fs/btrfs/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/bio.h>
   8 #include <linux/buffer_head.h>
   9 #include <linux/file.h>
  10 #include <linux/fs.h>
  11 #include <linux/fsnotify.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/highmem.h>
  14 #include <linux/time.h>
  15 #include <linux/init.h>
  16 #include <linux/string.h>
  17 #include <linux/backing-dev.h>
  18 #include <linux/mount.h>
  19 #include <linux/mpage.h>
  20 #include <linux/namei.h>
  21 #include <linux/swap.h>
  22 #include <linux/writeback.h>
  23 #include <linux/compat.h>
  24 #include <linux/bit_spinlock.h>
  25 #include <linux/security.h>
  26 #include <linux/xattr.h>
  27 #include <linux/mm.h>
  28 #include <linux/slab.h>
  29 #include <linux/blkdev.h>
  30 #include <linux/uuid.h>
  31 #include <linux/btrfs.h>
  32 #include <linux/uaccess.h>
  33 #include <linux/iversion.h>
  34 #include "ctree.h"
  35 #include "disk-io.h"
  36 #include "transaction.h"
  37 #include "btrfs_inode.h"
  38 #include "print-tree.h"
  39 #include "volumes.h"
  40 #include "locking.h"
  41 #include "inode-map.h"
  42 #include "backref.h"
  43 #include "rcu-string.h"
  44 #include "send.h"
  45 #include "dev-replace.h"
  46 #include "props.h"
  47 #include "sysfs.h"
  48 #include "qgroup.h"
  49 #include "tree-log.h"
  50 #include "compression.h"
  51
  52 #ifdef CONFIG_64BIT
  53 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  54  * structures are incorrect, as the timespec structure from userspace
  55  * is 4 bytes too small. We define these alternatives here to teach
  56  * the kernel about the 32-bit struct packing.
  57  */
  58 struct btrfs_ioctl_timespec_32 {
  59         __u64 sec;
  60         __u32 nsec;
  61 } __attribute__ ((__packed__));
  62
  63 struct btrfs_ioctl_received_subvol_args_32 {
  64         char    uuid[BTRFS_UUID_SIZE];  /* in */
  65         __u64   stransid;               /* in */
  66         __u64   rtransid;               /* out */
  67         struct btrfs_ioctl_timespec_32 stime; /* in */
  68         struct btrfs_ioctl_timespec_32 rtime; /* out */
  69         __u64   flags;                  /* in */
  70         __u64   reserved[16];           /* in */
  71 } __attribute__ ((__packed__));
  72
  73 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  74                                 struct btrfs_ioctl_received_subvol_args_32)
  75 #endif
  76
  77 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  78 struct btrfs_ioctl_send_args_32 {
  79         __s64 send_fd;                  /* in */
  80         __u64 clone_sources_count;      /* in */
  81         compat_uptr_t clone_sources;    /* in */
  82         __u64 parent_root;              /* in */
  83         __u64 flags;                    /* in */
  84         __u64 reserved[4];              /* in */
  85 } __attribute__ ((__packed__));
  86
  87 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  88                                struct btrfs_ioctl_send_args_32)
  89 #endif
  90
  91 static int btrfs_clone(struct inode *src, struct inode *inode,
  92                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  93                        int no_time_update);
  94
  95 /* Mask out flags that are inappropriate for the given type of inode. */
  96 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
  97                 unsigned int flags)
  98 {
  99         if (S_ISDIR(inode->i_mode))
 100                 return flags;
 101         else if (S_ISREG(inode->i_mode))
 102                 return flags & ~FS_DIRSYNC_FL;
 103         else
 104                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 105 }
 106
 107 /*
 108  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 109  * ioctl.
 110  */
 111 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
 112 {
 113         unsigned int iflags = 0;
 114
 115         if (flags & BTRFS_INODE_SYNC)
 116                 iflags |= FS_SYNC_FL;
 117         if (flags & BTRFS_INODE_IMMUTABLE)
 118                 iflags |= FS_IMMUTABLE_FL;
 119         if (flags & BTRFS_INODE_APPEND)
 120                 iflags |= FS_APPEND_FL;
 121         if (flags & BTRFS_INODE_NODUMP)
 122                 iflags |= FS_NODUMP_FL;
 123         if (flags & BTRFS_INODE_NOATIME)
 124                 iflags |= FS_NOATIME_FL;
 125         if (flags & BTRFS_INODE_DIRSYNC)
 126                 iflags |= FS_DIRSYNC_FL;
 127         if (flags & BTRFS_INODE_NODATACOW)
 128                 iflags |= FS_NOCOW_FL;
 129
 130         if (flags & BTRFS_INODE_NOCOMPRESS)
 131                 iflags |= FS_NOCOMP_FL;
 132         else if (flags & BTRFS_INODE_COMPRESS)
 133                 iflags |= FS_COMPR_FL;
 134
 135         return iflags;
 136 }
 137
 138 /*
 139  * Update inode->i_flags based on the btrfs internal flags.
 140  */
 141 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 142 {
 143         struct btrfs_inode *binode = BTRFS_I(inode);
 144         unsigned int new_fl = 0;
 145
 146         if (binode->flags & BTRFS_INODE_SYNC)
 147                 new_fl |= S_SYNC;
 148         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 149                 new_fl |= S_IMMUTABLE;
 150         if (binode->flags & BTRFS_INODE_APPEND)
 151                 new_fl |= S_APPEND;
 152         if (binode->flags & BTRFS_INODE_NOATIME)
 153                 new_fl |= S_NOATIME;
 154         if (binode->flags & BTRFS_INODE_DIRSYNC)
 155                 new_fl |= S_DIRSYNC;
 156
 157         set_mask_bits(&inode->i_flags,
 158                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 159                       new_fl);
 160 }
 161
 162 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 163 {
 164         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 165         unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
 166
 167         if (copy_to_user(arg, &flags, sizeof(flags)))
 168                 return -EFAULT;
 169         return 0;
 170 }
 171
 172 /* Check if @flags are a supported and valid set of FS_*_FL flags */
 173 static int check_fsflags(unsigned int flags)
 174 {
 175         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 176                       FS_NOATIME_FL | FS_NODUMP_FL | \
 177                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 178                       FS_NOCOMP_FL | FS_COMPR_FL |
 179                       FS_NOCOW_FL))
 180                 return -EOPNOTSUPP;
 181
 182         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 183                 return -EINVAL;
 184
 185         return 0;
 186 }
 187
 188 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 189 {
 190         struct inode *inode = file_inode(file);
 191         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 192         struct btrfs_inode *binode = BTRFS_I(inode);
 193         struct btrfs_root *root = binode->root;
 194         struct btrfs_trans_handle *trans;
 195         unsigned int fsflags, old_fsflags;
 196         int ret;
 197         u64 old_flags;
 198         unsigned int old_i_flags;
 199         umode_t mode;
 200
 201         if (!inode_owner_or_capable(inode))
 202                 return -EPERM;
 203
 204         if (btrfs_root_readonly(root))
 205                 return -EROFS;
 206
 207         if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
 208                 return -EFAULT;
 209
 210         ret = check_fsflags(fsflags);
 211         if (ret)
 212                 return ret;
 213
 214         ret = mnt_want_write_file(file);
 215         if (ret)
 216                 return ret;
 217
 218         inode_lock(inode);
 219
 220         old_flags = binode->flags;
 221         old_i_flags = inode->i_flags;
 222         mode = inode->i_mode;
 223
 224         fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
 225         old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
 226         if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 227                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 228                         ret = -EPERM;
 229                         goto out_unlock;
 230                 }
 231         }
 232
 233         if (fsflags & FS_SYNC_FL)
 234                 binode->flags |= BTRFS_INODE_SYNC;
 235         else
 236                 binode->flags &= ~BTRFS_INODE_SYNC;
 237         if (fsflags & FS_IMMUTABLE_FL)
 238                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 239         else
 240                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 241         if (fsflags & FS_APPEND_FL)
 242                 binode->flags |= BTRFS_INODE_APPEND;
 243         else
 244                 binode->flags &= ~BTRFS_INODE_APPEND;
 245         if (fsflags & FS_NODUMP_FL)
 246                 binode->flags |= BTRFS_INODE_NODUMP;
 247         else
 248                 binode->flags &= ~BTRFS_INODE_NODUMP;
 249         if (fsflags & FS_NOATIME_FL)
 250                 binode->flags |= BTRFS_INODE_NOATIME;
 251         else
 252                 binode->flags &= ~BTRFS_INODE_NOATIME;
 253         if (fsflags & FS_DIRSYNC_FL)
 254                 binode->flags |= BTRFS_INODE_DIRSYNC;
 255         else
 256                 binode->flags &= ~BTRFS_INODE_DIRSYNC;
 257         if (fsflags & FS_NOCOW_FL) {
 258                 if (S_ISREG(mode)) {
 259                         /*
 260                          * It's safe to turn csums off here, no extents exist.
 261                          * Otherwise we want the flag to reflect the real COW
 262                          * status of the file and will not set it.
 263                          */
 264                         if (inode->i_size == 0)
 265                                 binode->flags |= BTRFS_INODE_NODATACOW
 266                                               | BTRFS_INODE_NODATASUM;
 267                 } else {
 268                         binode->flags |= BTRFS_INODE_NODATACOW;
 269                 }
 270         } else {
 271                 /*
 272                  * Revert back under same assumptions as above
 273                  */
 274                 if (S_ISREG(mode)) {
 275                         if (inode->i_size == 0)
 276                                 binode->flags &= ~(BTRFS_INODE_NODATACOW
 277                                              | BTRFS_INODE_NODATASUM);
 278                 } else {
 279                         binode->flags &= ~BTRFS_INODE_NODATACOW;
 280                 }
 281         }
 282
 283         /*
 284          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 285          * flag may be changed automatically if compression code won't make
 286          * things smaller.
 287          */
 288         if (fsflags & FS_NOCOMP_FL) {
 289                 binode->flags &= ~BTRFS_INODE_COMPRESS;
 290                 binode->flags |= BTRFS_INODE_NOCOMPRESS;
 291
 292                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 293                 if (ret && ret != -ENODATA)
 294                         goto out_drop;
 295         } else if (fsflags & FS_COMPR_FL) {
 296                 const char *comp;
 297
 298                 binode->flags |= BTRFS_INODE_COMPRESS;
 299                 binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
 300
 301                 comp = btrfs_compress_type2str(fs_info->compress_type);
 302                 if (!comp || comp[0] == 0)
 303                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 304
 305                 ret = btrfs_set_prop(inode, "btrfs.compression",
 306                                      comp, strlen(comp), 0);
 307                 if (ret)
 308                         goto out_drop;
 309
 310         } else {
 311                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 312                 if (ret && ret != -ENODATA)
 313                         goto out_drop;
 314                 binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 315         }
 316
 317         trans = btrfs_start_transaction(root, 1);
 318         if (IS_ERR(trans)) {
 319                 ret = PTR_ERR(trans);
 320                 goto out_drop;
 321         }
 322
 323         btrfs_sync_inode_flags_to_i_flags(inode);
 324         inode_inc_iversion(inode);
 325         inode->i_ctime = current_time(inode);
 326         ret = btrfs_update_inode(trans, root, inode);
 327
 328         btrfs_end_transaction(trans);
 329  out_drop:
 330         if (ret) {
 331                 binode->flags = old_flags;
 332                 inode->i_flags = old_i_flags;
 333         }
 334
 335  out_unlock:
 336         inode_unlock(inode);
 337         mnt_drop_write_file(file);
 338         return ret;
 339 }
 340
 341 /*
 342  * Translate btrfs internal inode flags to xflags as expected by the
 343  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
 344  * silently dropped.
 345  */
 346 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
 347 {
 348         unsigned int xflags = 0;
 349
 350         if (flags & BTRFS_INODE_APPEND)
 351                 xflags |= FS_XFLAG_APPEND;
 352         if (flags & BTRFS_INODE_IMMUTABLE)
 353                 xflags |= FS_XFLAG_IMMUTABLE;
 354         if (flags & BTRFS_INODE_NOATIME)
 355                 xflags |= FS_XFLAG_NOATIME;
 356         if (flags & BTRFS_INODE_NODUMP)
 357                 xflags |= FS_XFLAG_NODUMP;
 358         if (flags & BTRFS_INODE_SYNC)
 359                 xflags |= FS_XFLAG_SYNC;
 360
 361         return xflags;
 362 }
 363
 364 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
 365 static int check_xflags(unsigned int flags)
 366 {
 367         if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
 368                       FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
 369                 return -EOPNOTSUPP;
 370         return 0;
 371 }
 372
 373 /*
 374  * Set the xflags from the internal inode flags. The remaining items of fsxattr
 375  * are zeroed.
 376  */
 377 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
 378 {
 379         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 380         struct fsxattr fa;
 381
 382         memset(&fa, 0, sizeof(fa));
 383         fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
 384
 385         if (copy_to_user(arg, &fa, sizeof(fa)))
 386                 return -EFAULT;
 387
 388         return 0;
 389 }
 390
 391 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
 392 {
 393         struct inode *inode = file_inode(file);
 394         struct btrfs_inode *binode = BTRFS_I(inode);
 395         struct btrfs_root *root = binode->root;
 396         struct btrfs_trans_handle *trans;
 397         struct fsxattr fa;
 398         unsigned old_flags;
 399         unsigned old_i_flags;
 400         int ret = 0;
 401
 402         if (!inode_owner_or_capable(inode))
 403                 return -EPERM;
 404
 405         if (btrfs_root_readonly(root))
 406                 return -EROFS;
 407
 408         memset(&fa, 0, sizeof(fa));
 409         if (copy_from_user(&fa, arg, sizeof(fa)))
 410                 return -EFAULT;
 411
 412         ret = check_xflags(fa.fsx_xflags);
 413         if (ret)
 414                 return ret;
 415
 416         if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
 417                 return -EOPNOTSUPP;
 418
 419         ret = mnt_want_write_file(file);
 420         if (ret)
 421                 return ret;
 422
 423         inode_lock(inode);
 424
 425         old_flags = binode->flags;
 426         old_i_flags = inode->i_flags;
 427
 428         /* We need the capabilities to change append-only or immutable inode */
 429         if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
 430              (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
 431             !capable(CAP_LINUX_IMMUTABLE)) {
 432                 ret = -EPERM;
 433                 goto out_unlock;
 434         }
 435
 436         if (fa.fsx_xflags & FS_XFLAG_SYNC)
 437                 binode->flags |= BTRFS_INODE_SYNC;
 438         else
 439                 binode->flags &= ~BTRFS_INODE_SYNC;
 440         if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
 441                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 442         else
 443                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 444         if (fa.fsx_xflags & FS_XFLAG_APPEND)
 445                 binode->flags |= BTRFS_INODE_APPEND;
 446         else
 447                 binode->flags &= ~BTRFS_INODE_APPEND;
 448         if (fa.fsx_xflags & FS_XFLAG_NODUMP)
 449                 binode->flags |= BTRFS_INODE_NODUMP;
 450         else
 451                 binode->flags &= ~BTRFS_INODE_NODUMP;
 452         if (fa.fsx_xflags & FS_XFLAG_NOATIME)
 453                 binode->flags |= BTRFS_INODE_NOATIME;
 454         else
 455                 binode->flags &= ~BTRFS_INODE_NOATIME;
 456
 457         /* 1 item for the inode */
 458         trans = btrfs_start_transaction(root, 1);
 459         if (IS_ERR(trans)) {
 460                 ret = PTR_ERR(trans);
 461                 goto out_unlock;
 462         }
 463
 464         btrfs_sync_inode_flags_to_i_flags(inode);
 465         inode_inc_iversion(inode);
 466         inode->i_ctime = current_time(inode);
 467         ret = btrfs_update_inode(trans, root, inode);
 468
 469         btrfs_end_transaction(trans);
 470
 471 out_unlock:
 472         if (ret) {
 473                 binode->flags = old_flags;
 474                 inode->i_flags = old_i_flags;
 475         }
 476
 477         inode_unlock(inode);
 478         mnt_drop_write_file(file);
 479
 480         return ret;
 481 }
 482
 483 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 484 {
 485         struct inode *inode = file_inode(file);
 486
 487         return put_user(inode->i_generation, arg);
 488 }
 489
 490 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 491 {
 492         struct inode *inode = file_inode(file);
 493         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 494         struct btrfs_device *device;
 495         struct request_queue *q;
 496         struct fstrim_range range;
 497         u64 minlen = ULLONG_MAX;
 498         u64 num_devices = 0;
 499         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 500         int ret;
 501
 502         if (!capable(CAP_SYS_ADMIN))
 503                 return -EPERM;
 504
 505         rcu_read_lock();
 506         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 507                                 dev_list) {
 508                 if (!device->bdev)
 509                         continue;
 510                 q = bdev_get_queue(device->bdev);
 511                 if (blk_queue_discard(q)) {
 512                         num_devices++;
 513                         minlen = min_t(u64, q->limits.discard_granularity,
 514                                      minlen);
 515                 }
 516         }
 517         rcu_read_unlock();
 518
 519         if (!num_devices)
 520                 return -EOPNOTSUPP;
 521         if (copy_from_user(&range, arg, sizeof(range)))
 522                 return -EFAULT;
 523         if (range.start > total_bytes ||
 524             range.len < fs_info->sb->s_blocksize)
 525                 return -EINVAL;
 526
 527         range.len = min(range.len, total_bytes - range.start);
 528         range.minlen = max(range.minlen, minlen);
 529         ret = btrfs_trim_fs(fs_info, &range);
 530         if (ret < 0)
 531                 return ret;
 532
 533         if (copy_to_user(arg, &range, sizeof(range)))
 534                 return -EFAULT;
 535
 536         return 0;
 537 }
 538
 539 int btrfs_is_empty_uuid(u8 *uuid)
 540 {
 541         int i;
 542
 543         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 544                 if (uuid[i])
 545                         return 0;
 546         }
 547         return 1;
 548 }
 549
 550 static noinline int create_subvol(struct inode *dir,
 551                                   struct dentry *dentry,
 552                                   const char *name, int namelen,
 553                                   u64 *async_transid,
 554                                   struct btrfs_qgroup_inherit *inherit)
 555 {
 556         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 557         struct btrfs_trans_handle *trans;
 558         struct btrfs_key key;
 559         struct btrfs_root_item *root_item;
 560         struct btrfs_inode_item *inode_item;
 561         struct extent_buffer *leaf;
 562         struct btrfs_root *root = BTRFS_I(dir)->root;
 563         struct btrfs_root *new_root;
 564         struct btrfs_block_rsv block_rsv;
 565         struct timespec64 cur_time = current_time(dir);
 566         struct inode *inode;
 567         int ret;
 568         int err;
 569         u64 objectid;
 570         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 571         u64 index = 0;
 572         uuid_le new_uuid;
 573
 574         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 575         if (!root_item)
 576                 return -ENOMEM;
 577
 578         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 579         if (ret)
 580                 goto fail_free;
 581
 582         /*
 583          * Don't create subvolume whose level is not zero. Or qgroup will be
 584          * screwed up since it assumes subvolume qgroup's level to be 0.
 585          */
 586         if (btrfs_qgroup_level(objectid)) {
 587                 ret = -ENOSPC;
 588                 goto fail_free;
 589         }
 590
 591         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 592         /*
 593          * The same as the snapshot creation, please see the comment
 594          * of create_snapshot().
 595          */
 596         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
 597         if (ret)
 598                 goto fail_free;
 599
 600         trans = btrfs_start_transaction(root, 0);
 601         if (IS_ERR(trans)) {
 602                 ret = PTR_ERR(trans);
 603                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 604                 goto fail_free;
 605         }
 606         trans->block_rsv = &block_rsv;
 607         trans->bytes_reserved = block_rsv.size;
 608
 609         ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 610         if (ret)
 611                 goto fail;
 612
 613         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 614         if (IS_ERR(leaf)) {
 615                 ret = PTR_ERR(leaf);
 616                 goto fail;
 617         }
 618
 619         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
 620         btrfs_set_header_bytenr(leaf, leaf->start);
 621         btrfs_set_header_generation(leaf, trans->transid);
 622         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 623         btrfs_set_header_owner(leaf, objectid);
 624
 625         write_extent_buffer_fsid(leaf, fs_info->fsid);
 626         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 627         btrfs_mark_buffer_dirty(leaf);
 628
 629         inode_item = &root_item->inode;
 630         btrfs_set_stack_inode_generation(inode_item, 1);
 631         btrfs_set_stack_inode_size(inode_item, 3);
 632         btrfs_set_stack_inode_nlink(inode_item, 1);
 633         btrfs_set_stack_inode_nbytes(inode_item,
 634                                      fs_info->nodesize);
 635         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 636
 637         btrfs_set_root_flags(root_item, 0);
 638         btrfs_set_root_limit(root_item, 0);
 639         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 640
 641         btrfs_set_root_bytenr(root_item, leaf->start);
 642         btrfs_set_root_generation(root_item, trans->transid);
 643         btrfs_set_root_level(root_item, 0);
 644         btrfs_set_root_refs(root_item, 1);
 645         btrfs_set_root_used(root_item, leaf->len);
 646         btrfs_set_root_last_snapshot(root_item, 0);
 647
 648         btrfs_set_root_generation_v2(root_item,
 649                         btrfs_root_generation(root_item));
 650         uuid_le_gen(&new_uuid);
 651         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 652         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 653         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 654         root_item->ctime = root_item->otime;
 655         btrfs_set_root_ctransid(root_item, trans->transid);
 656         btrfs_set_root_otransid(root_item, trans->transid);
 657
 658         btrfs_tree_unlock(leaf);
 659         free_extent_buffer(leaf);
 660         leaf = NULL;
 661
 662         btrfs_set_root_dirid(root_item, new_dirid);
 663
 664         key.objectid = objectid;
 665         key.offset = 0;
 666         key.type = BTRFS_ROOT_ITEM_KEY;
 667         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 668                                 root_item);
 669         if (ret)
 670                 goto fail;
 671
 672         key.offset = (u64)-1;
 673         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 674         if (IS_ERR(new_root)) {
 675                 ret = PTR_ERR(new_root);
 676                 btrfs_abort_transaction(trans, ret);
 677                 goto fail;
 678         }
 679
 680         btrfs_record_root_in_trans(trans, new_root);
 681
 682         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 683         if (ret) {
 684                 /* We potentially lose an unused inode item here */
 685                 btrfs_abort_transaction(trans, ret);
 686                 goto fail;
 687         }
 688
 689         mutex_lock(&new_root->objectid_mutex);
 690         new_root->highest_objectid = new_dirid;
 691         mutex_unlock(&new_root->objectid_mutex);
 692
 693         /*
 694          * insert the directory item
 695          */
 696         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 697         if (ret) {
 698                 btrfs_abort_transaction(trans, ret);
 699                 goto fail;
 700         }
 701
 702         ret = btrfs_insert_dir_item(trans, root,
 703                                     name, namelen, BTRFS_I(dir), &key,
 704                                     BTRFS_FT_DIR, index);
 705         if (ret) {
 706                 btrfs_abort_transaction(trans, ret);
 707                 goto fail;
 708         }
 709
 710         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 711         ret = btrfs_update_inode(trans, root, dir);
 712         BUG_ON(ret);
 713
 714         ret = btrfs_add_root_ref(trans, fs_info,
 715                                  objectid, root->root_key.objectid,
 716                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 717         BUG_ON(ret);
 718
 719         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 720                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 721         if (ret)
 722                 btrfs_abort_transaction(trans, ret);
 723
 724 fail:
 725         kfree(root_item);
 726         trans->block_rsv = NULL;
 727         trans->bytes_reserved = 0;
 728         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 729
 730         if (async_transid) {
 731                 *async_transid = trans->transid;
 732                 err = btrfs_commit_transaction_async(trans, 1);
 733                 if (err)
 734                         err = btrfs_commit_transaction(trans);
 735         } else {
 736                 err = btrfs_commit_transaction(trans);
 737         }
 738         if (err && !ret)
 739                 ret = err;
 740
 741         if (!ret) {
 742                 inode = btrfs_lookup_dentry(dir, dentry);
 743                 if (IS_ERR(inode))
 744                         return PTR_ERR(inode);
 745                 d_instantiate(dentry, inode);
 746         }
 747         return ret;
 748
 749 fail_free:
 750         kfree(root_item);
 751         return ret;
 752 }
 753
 754 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 755                            struct dentry *dentry,
 756                            u64 *async_transid, bool readonly,
 757                            struct btrfs_qgroup_inherit *inherit)
 758 {
 759         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 760         struct inode *inode;
 761         struct btrfs_pending_snapshot *pending_snapshot;
 762         struct btrfs_trans_handle *trans;
 763         int ret;
 764
 765         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 766                 return -EINVAL;
 767
 768         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 769         if (!pending_snapshot)
 770                 return -ENOMEM;
 771
 772         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 773                         GFP_KERNEL);
 774         pending_snapshot->path = btrfs_alloc_path();
 775         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 776                 ret = -ENOMEM;
 777                 goto free_pending;
 778         }
 779
 780         atomic_inc(&root->will_be_snapshotted);
 781         smp_mb__after_atomic();
 782         /* wait for no snapshot writes */
 783         wait_event(root->subv_writers->wait,
 784                    percpu_counter_sum(&root->subv_writers->counter) == 0);
 785
 786         ret = btrfs_start_delalloc_inodes(root);
 787         if (ret)
 788                 goto dec_and_free;
 789
 790         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 791
 792         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 793                              BTRFS_BLOCK_RSV_TEMP);
 794         /*
 795          * 1 - parent dir inode
 796          * 2 - dir entries
 797          * 1 - root item
 798          * 2 - root ref/backref
 799          * 1 - root of snapshot
 800          * 1 - UUID item
 801          */
 802         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 803                                         &pending_snapshot->block_rsv, 8,
 804                                         false);
 805         if (ret)
 806                 goto dec_and_free;
 807
 808         pending_snapshot->dentry = dentry;
 809         pending_snapshot->root = root;
 810         pending_snapshot->readonly = readonly;
 811         pending_snapshot->dir = dir;
 812         pending_snapshot->inherit = inherit;
 813
 814         trans = btrfs_start_transaction(root, 0);
 815         if (IS_ERR(trans)) {
 816                 ret = PTR_ERR(trans);
 817                 goto fail;
 818         }
 819
 820         spin_lock(&fs_info->trans_lock);
 821         list_add(&pending_snapshot->list,
 822                  &trans->transaction->pending_snapshots);
 823         spin_unlock(&fs_info->trans_lock);
 824         if (async_transid) {
 825                 *async_transid = trans->transid;
 826                 ret = btrfs_commit_transaction_async(trans, 1);
 827                 if (ret)
 828                         ret = btrfs_commit_transaction(trans);
 829         } else {
 830                 ret = btrfs_commit_transaction(trans);
 831         }
 832         if (ret)
 833                 goto fail;
 834
 835         ret = pending_snapshot->error;
 836         if (ret)
 837                 goto fail;
 838
 839         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 840         if (ret)
 841                 goto fail;
 842
 843         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 844         if (IS_ERR(inode)) {
 845                 ret = PTR_ERR(inode);
 846                 goto fail;
 847         }
 848
 849         d_instantiate(dentry, inode);
 850         ret = 0;
 851 fail:
 852         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 853 dec_and_free:
 854         if (atomic_dec_and_test(&root->will_be_snapshotted))
 855                 wake_up_var(&root->will_be_snapshotted);
 856 free_pending:
 857         kfree(pending_snapshot->root_item);
 858         btrfs_free_path(pending_snapshot->path);
 859         kfree(pending_snapshot);
 860
 861         return ret;
 862 }
 863
 864 /*  copy of may_delete in fs/namei.c()
 865  *      Check whether we can remove a link victim from directory dir, check
 866  *  whether the type of victim is right.
 867  *  1. We can't do it if dir is read-only (done in permission())
 868  *  2. We should have write and exec permissions on dir
 869  *  3. We can't remove anything from append-only dir
 870  *  4. We can't do anything with immutable dir (done in permission())
 871  *  5. If the sticky bit on dir is set we should either
 872  *      a. be owner of dir, or
 873  *      b. be owner of victim, or
 874  *      c. have CAP_FOWNER capability
 875  *  6. If the victim is append-only or immutable we can't do anything with
 876  *     links pointing to it.
 877  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 878  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 879  *  9. We can't remove a root or mountpoint.
 880  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 881  *     nfs_async_unlink().
 882  */
 883
 884 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 885 {
 886         int error;
 887
 888         if (d_really_is_negative(victim))
 889                 return -ENOENT;
 890
 891         BUG_ON(d_inode(victim->d_parent) != dir);
 892         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 893
 894         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 895         if (error)
 896                 return error;
 897         if (IS_APPEND(dir))
 898                 return -EPERM;
 899         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 900             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 901                 return -EPERM;
 902         if (isdir) {
 903                 if (!d_is_dir(victim))
 904                         return -ENOTDIR;
 905                 if (IS_ROOT(victim))
 906                         return -EBUSY;
 907         } else if (d_is_dir(victim))
 908                 return -EISDIR;
 909         if (IS_DEADDIR(dir))
 910                 return -ENOENT;
 911         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 912                 return -EBUSY;
 913         return 0;
 914 }
 915
 916 /* copy of may_create in fs/namei.c() */
 917 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 918 {
 919         if (d_really_is_positive(child))
 920                 return -EEXIST;
 921         if (IS_DEADDIR(dir))
 922                 return -ENOENT;
 923         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 924 }
 925
 926 /*
 927  * Create a new subvolume below @parent.  This is largely modeled after
 928  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 929  * inside this filesystem so it's quite a bit simpler.
 930  */
 931 static noinline int btrfs_mksubvol(const struct path *parent,
 932                                    const char *name, int namelen,
 933                                    struct btrfs_root *snap_src,
 934                                    u64 *async_transid, bool readonly,
 935                                    struct btrfs_qgroup_inherit *inherit)
 936 {
 937         struct inode *dir = d_inode(parent->dentry);
 938         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 939         struct dentry *dentry;
 940         int error;
 941
 942         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 943         if (error == -EINTR)
 944                 return error;
 945
 946         dentry = lookup_one_len(name, parent->dentry, namelen);
 947         error = PTR_ERR(dentry);
 948         if (IS_ERR(dentry))
 949                 goto out_unlock;
 950
 951         error = btrfs_may_create(dir, dentry);
 952         if (error)
 953                 goto out_dput;
 954
 955         /*
 956          * even if this name doesn't exist, we may get hash collisions.
 957          * check for them now when we can safely fail
 958          */
 959         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 960                                                dir->i_ino, name,
 961                                                namelen);
 962         if (error)
 963                 goto out_dput;
 964
 965         down_read(&fs_info->subvol_sem);
 966
 967         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 968                 goto out_up_read;
 969
 970         if (snap_src) {
 971                 error = create_snapshot(snap_src, dir, dentry,
 972                                         async_transid, readonly, inherit);
 973         } else {
 974                 error = create_subvol(dir, dentry, name, namelen,
 975                                       async_transid, inherit);
 976         }
 977         if (!error)
 978                 fsnotify_mkdir(dir, dentry);
 979 out_up_read:
 980         up_read(&fs_info->subvol_sem);
 981 out_dput:
 982         dput(dentry);
 983 out_unlock:
 984         inode_unlock(dir);
 985         return error;
 986 }
 987
 988 /*
 989  * When we're defragging a range, we don't want to kick it off again
 990  * if it is really just waiting for delalloc to send it down.
 991  * If we find a nice big extent or delalloc range for the bytes in the
 992  * file you want to defrag, we return 0 to let you know to skip this
 993  * part of the file
 994  */
 995 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 996 {
 997         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 998         struct extent_map *em = NULL;
 999         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1000         u64 end;
1001
1002         read_lock(&em_tree->lock);
1003         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1004         read_unlock(&em_tree->lock);
1005
1006         if (em) {
1007                 end = extent_map_end(em);
1008                 free_extent_map(em);
1009                 if (end - offset > thresh)
1010                         return 0;
1011         }
1012         /* if we already have a nice delalloc here, just stop */
1013         thresh /= 2;
1014         end = count_range_bits(io_tree, &offset, offset + thresh,
1015                                thresh, EXTENT_DELALLOC, 1);
1016         if (end >= thresh)
1017                 return 0;
1018         return 1;
1019 }
1020
1021 /*
1022  * helper function to walk through a file and find extents
1023  * newer than a specific transid, and smaller than thresh.
1024  *
1025  * This is used by the defragging code to find new and small
1026  * extents
1027  */
1028 static int find_new_extents(struct btrfs_root *root,
1029                             struct inode *inode, u64 newer_than,
1030                             u64 *off, u32 thresh)
1031 {
1032         struct btrfs_path *path;
1033         struct btrfs_key min_key;
1034         struct extent_buffer *leaf;
1035         struct btrfs_file_extent_item *extent;
1036         int type;
1037         int ret;
1038         u64 ino = btrfs_ino(BTRFS_I(inode));
1039
1040         path = btrfs_alloc_path();
1041         if (!path)
1042                 return -ENOMEM;
1043
1044         min_key.objectid = ino;
1045         min_key.type = BTRFS_EXTENT_DATA_KEY;
1046         min_key.offset = *off;
1047
1048         while (1) {
1049                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
1050                 if (ret != 0)
1051                         goto none;
1052 process_slot:
1053                 if (min_key.objectid != ino)
1054                         goto none;
1055                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1056                         goto none;
1057
1058                 leaf = path->nodes[0];
1059                 extent = btrfs_item_ptr(leaf, path->slots[0],
1060                                         struct btrfs_file_extent_item);
1061
1062                 type = btrfs_file_extent_type(leaf, extent);
1063                 if (type == BTRFS_FILE_EXTENT_REG &&
1064                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1065                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
1066                         *off = min_key.offset;
1067                         btrfs_free_path(path);
1068                         return 0;
1069                 }
1070
1071                 path->slots[0]++;
1072                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
1073                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1074                         goto process_slot;
1075                 }
1076
1077                 if (min_key.offset == (u64)-1)
1078                         goto none;
1079
1080                 min_key.offset++;
1081                 btrfs_release_path(path);
1082         }
1083 none:
1084         btrfs_free_path(path);
1085         return -ENOENT;
1086 }
1087
1088 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1089 {
1090         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1091         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1092         struct extent_map *em;
1093         u64 len = PAGE_SIZE;
1094
1095         /*
1096          * hopefully we have this extent in the tree already, try without
1097          * the full extent lock
1098          */
1099         read_lock(&em_tree->lock);
1100         em = lookup_extent_mapping(em_tree, start, len);
1101         read_unlock(&em_tree->lock);
1102
1103         if (!em) {
1104                 struct extent_state *cached = NULL;
1105                 u64 end = start + len - 1;
1106
1107                 /* get the big lock and read metadata off disk */
1108                 lock_extent_bits(io_tree, start, end, &cached);
1109                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1110                 unlock_extent_cached(io_tree, start, end, &cached);
1111
1112                 if (IS_ERR(em))
1113                         return NULL;
1114         }
1115
1116         return em;
1117 }
1118
1119 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1120 {
1121         struct extent_map *next;
1122         bool ret = true;
1123
1124         /* this is the last extent */
1125         if (em->start + em->len >= i_size_read(inode))
1126                 return false;
1127
1128         next = defrag_lookup_extent(inode, em->start + em->len);
1129         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1130                 ret = false;
1131         else if ((em->block_start + em->block_len == next->block_start) &&
1132                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1133                 ret = false;
1134
1135         free_extent_map(next);
1136         return ret;
1137 }
1138
1139 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1140                                u64 *last_len, u64 *skip, u64 *defrag_end,
1141                                int compress)
1142 {
1143         struct extent_map *em;
1144         int ret = 1;
1145         bool next_mergeable = true;
1146         bool prev_mergeable = true;
1147
1148         /*
1149          * make sure that once we start defragging an extent, we keep on
1150          * defragging it
1151          */
1152         if (start < *defrag_end)
1153                 return 1;
1154
1155         *skip = 0;
1156
1157         em = defrag_lookup_extent(inode, start);
1158         if (!em)
1159                 return 0;
1160
1161         /* this will cover holes, and inline extents */
1162         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1163                 ret = 0;
1164                 goto out;
1165         }
1166
1167         if (!*defrag_end)
1168                 prev_mergeable = false;
1169
1170         next_mergeable = defrag_check_next_extent(inode, em);
1171         /*
1172          * we hit a real extent, if it is big or the next extent is not a
1173          * real extent, don't bother defragging it
1174          */
1175         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1176             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1177                 ret = 0;
1178 out:
1179         /*
1180          * last_len ends up being a counter of how many bytes we've defragged.
1181          * every time we choose not to defrag an extent, we reset *last_len
1182          * so that the next tiny extent will force a defrag.
1183          *
1184          * The end result of this is that tiny extents before a single big
1185          * extent will force at least part of that big extent to be defragged.
1186          */
1187         if (ret) {
1188                 *defrag_end = extent_map_end(em);
1189         } else {
1190                 *last_len = 0;
1191                 *skip = extent_map_end(em);
1192                 *defrag_end = 0;
1193         }
1194
1195         free_extent_map(em);
1196         return ret;
1197 }
1198
1199 /*
1200  * it doesn't do much good to defrag one or two pages
1201  * at a time.  This pulls in a nice chunk of pages
1202  * to COW and defrag.
1203  *
1204  * It also makes sure the delalloc code has enough
1205  * dirty data to avoid making new small extents as part
1206  * of the defrag
1207  *
1208  * It's a good idea to start RA on this range
1209  * before calling this.
1210  */
1211 static int cluster_pages_for_defrag(struct inode *inode,
1212                                     struct page **pages,
1213                                     unsigned long start_index,
1214                                     unsigned long num_pages)
1215 {
1216         unsigned long file_end;
1217         u64 isize = i_size_read(inode);
1218         u64 page_start;
1219         u64 page_end;
1220         u64 page_cnt;
1221         int ret;
1222         int i;
1223         int i_done;
1224         struct btrfs_ordered_extent *ordered;
1225         struct extent_state *cached_state = NULL;
1226         struct extent_io_tree *tree;
1227         struct extent_changeset *data_reserved = NULL;
1228         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1229
1230         file_end = (isize - 1) >> PAGE_SHIFT;
1231         if (!isize || start_index > file_end)
1232                 return 0;
1233
1234         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1235
1236         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1237                         start_index << PAGE_SHIFT,
1238                         page_cnt << PAGE_SHIFT);
1239         if (ret)
1240                 return ret;
1241         i_done = 0;
1242         tree = &BTRFS_I(inode)->io_tree;
1243
1244         /* step one, lock all the pages */
1245         for (i = 0; i < page_cnt; i++) {
1246                 struct page *page;
1247 again:
1248                 page = find_or_create_page(inode->i_mapping,
1249                                            start_index + i, mask);
1250                 if (!page)
1251                         break;
1252
1253                 page_start = page_offset(page);
1254                 page_end = page_start + PAGE_SIZE - 1;
1255                 while (1) {
1256                         lock_extent_bits(tree, page_start, page_end,
1257                                          &cached_state);
1258                         ordered = btrfs_lookup_ordered_extent(inode,
1259                                                               page_start);
1260                         unlock_extent_cached(tree, page_start, page_end,
1261                                              &cached_state);
1262                         if (!ordered)
1263                                 break;
1264
1265                         unlock_page(page);
1266                         btrfs_start_ordered_extent(inode, ordered, 1);
1267                         btrfs_put_ordered_extent(ordered);
1268                         lock_page(page);
1269                         /*
1270                          * we unlocked the page above, so we need check if
1271                          * it was released or not.
1272                          */
1273                         if (page->mapping != inode->i_mapping) {
1274                                 unlock_page(page);
1275                                 put_page(page);
1276                                 goto again;
1277                         }
1278                 }
1279
1280                 if (!PageUptodate(page)) {
1281                         btrfs_readpage(NULL, page);
1282                         lock_page(page);
1283                         if (!PageUptodate(page)) {
1284                                 unlock_page(page);
1285                                 put_page(page);
1286                                 ret = -EIO;
1287                                 break;
1288                         }
1289                 }
1290
1291                 if (page->mapping != inode->i_mapping) {
1292                         unlock_page(page);
1293                         put_page(page);
1294                         goto again;
1295                 }
1296
1297                 pages[i] = page;
1298                 i_done++;
1299         }
1300         if (!i_done || ret)
1301                 goto out;
1302
1303         if (!(inode->i_sb->s_flags & SB_ACTIVE))
1304                 goto out;
1305
1306         /*
1307          * so now we have a nice long stream of locked
1308          * and up to date pages, lets wait on them
1309          */
1310         for (i = 0; i < i_done; i++)
1311                 wait_on_page_writeback(pages[i]);
1312
1313         page_start = page_offset(pages[0]);
1314         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1315
1316         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1317                          page_start, page_end - 1, &cached_state);
1318         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1319                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1320                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1321                           &cached_state);
1322
1323         if (i_done != page_cnt) {
1324                 spin_lock(&BTRFS_I(inode)->lock);
1325                 BTRFS_I(inode)->outstanding_extents++;
1326                 spin_unlock(&BTRFS_I(inode)->lock);
1327                 btrfs_delalloc_release_space(inode, data_reserved,
1328                                 start_index << PAGE_SHIFT,
1329                                 (page_cnt - i_done) << PAGE_SHIFT, true);
1330         }
1331
1332
1333         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1334                           &cached_state);
1335
1336         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1337                              page_start, page_end - 1, &cached_state);
1338
1339         for (i = 0; i < i_done; i++) {
1340                 clear_page_dirty_for_io(pages[i]);
1341                 ClearPageChecked(pages[i]);
1342                 set_page_extent_mapped(pages[i]);
1343                 set_page_dirty(pages[i]);
1344                 unlock_page(pages[i]);
1345                 put_page(pages[i]);
1346         }
1347         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1348                                        false);
1349         extent_changeset_free(data_reserved);
1350         return i_done;
1351 out:
1352         for (i = 0; i < i_done; i++) {
1353                 unlock_page(pages[i]);
1354                 put_page(pages[i]);
1355         }
1356         btrfs_delalloc_release_space(inode, data_reserved,
1357                         start_index << PAGE_SHIFT,
1358                         page_cnt << PAGE_SHIFT, true);
1359         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1360                                        true);
1361         extent_changeset_free(data_reserved);
1362         return ret;
1363
1364 }
1365
1366 int btrfs_defrag_file(struct inode *inode, struct file *file,
1367                       struct btrfs_ioctl_defrag_range_args *range,
1368                       u64 newer_than, unsigned long max_to_defrag)
1369 {
1370         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1371         struct btrfs_root *root = BTRFS_I(inode)->root;
1372         struct file_ra_state *ra = NULL;
1373         unsigned long last_index;
1374         u64 isize = i_size_read(inode);
1375         u64 last_len = 0;
1376         u64 skip = 0;
1377         u64 defrag_end = 0;
1378         u64 newer_off = range->start;
1379         unsigned long i;
1380         unsigned long ra_index = 0;
1381         int ret;
1382         int defrag_count = 0;
1383         int compress_type = BTRFS_COMPRESS_ZLIB;
1384         u32 extent_thresh = range->extent_thresh;
1385         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1386         unsigned long cluster = max_cluster;
1387         u64 new_align = ~((u64)SZ_128K - 1);
1388         struct page **pages = NULL;
1389         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1390
1391         if (isize == 0)
1392                 return 0;
1393
1394         if (range->start >= isize)
1395                 return -EINVAL;
1396
1397         if (do_compress) {
1398                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1399                         return -EINVAL;
1400                 if (range->compress_type)
1401                         compress_type = range->compress_type;
1402         }
1403
1404         if (extent_thresh == 0)
1405                 extent_thresh = SZ_256K;
1406
1407         /*
1408          * If we were not given a file, allocate a readahead context. As
1409          * readahead is just an optimization, defrag will work without it so
1410          * we don't error out.
1411          */
1412         if (!file) {
1413                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1414                 if (ra)
1415                         file_ra_state_init(ra, inode->i_mapping);
1416         } else {
1417                 ra = &file->f_ra;
1418         }
1419
1420         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1421         if (!pages) {
1422                 ret = -ENOMEM;
1423                 goto out_ra;
1424         }
1425
1426         /* find the last page to defrag */
1427         if (range->start + range->len > range->start) {
1428                 last_index = min_t(u64, isize - 1,
1429                          range->start + range->len - 1) >> PAGE_SHIFT;
1430         } else {
1431                 last_index = (isize - 1) >> PAGE_SHIFT;
1432         }
1433
1434         if (newer_than) {
1435                 ret = find_new_extents(root, inode, newer_than,
1436                                        &newer_off, SZ_64K);
1437                 if (!ret) {
1438                         range->start = newer_off;
1439                         /*
1440                          * we always align our defrag to help keep
1441                          * the extents in the file evenly spaced
1442                          */
1443                         i = (newer_off & new_align) >> PAGE_SHIFT;
1444                 } else
1445                         goto out_ra;
1446         } else {
1447                 i = range->start >> PAGE_SHIFT;
1448         }
1449         if (!max_to_defrag)
1450                 max_to_defrag = last_index - i + 1;
1451
1452         /*
1453          * make writeback starts from i, so the defrag range can be
1454          * written sequentially.
1455          */
1456         if (i < inode->i_mapping->writeback_index)
1457                 inode->i_mapping->writeback_index = i;
1458
1459         while (i <= last_index && defrag_count < max_to_defrag &&
1460                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1461                 /*
1462                  * make sure we stop running if someone unmounts
1463                  * the FS
1464                  */
1465                 if (!(inode->i_sb->s_flags & SB_ACTIVE))
1466                         break;
1467
1468                 if (btrfs_defrag_cancelled(fs_info)) {
1469                         btrfs_debug(fs_info, "defrag_file cancelled");
1470                         ret = -EAGAIN;
1471                         break;
1472                 }
1473
1474                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1475                                          extent_thresh, &last_len, &skip,
1476                                          &defrag_end, do_compress)){
1477                         unsigned long next;
1478                         /*
1479                          * the should_defrag function tells us how much to skip
1480                          * bump our counter by the suggested amount
1481                          */
1482                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1483                         i = max(i + 1, next);
1484                         continue;
1485                 }
1486
1487                 if (!newer_than) {
1488                         cluster = (PAGE_ALIGN(defrag_end) >>
1489                                    PAGE_SHIFT) - i;
1490                         cluster = min(cluster, max_cluster);
1491                 } else {
1492                         cluster = max_cluster;
1493                 }
1494
1495                 if (i + cluster > ra_index) {
1496                         ra_index = max(i, ra_index);
1497                         if (ra)
1498                                 page_cache_sync_readahead(inode->i_mapping, ra,
1499                                                 file, ra_index, cluster);
1500                         ra_index += cluster;
1501                 }
1502
1503                 inode_lock(inode);
1504                 if (do_compress)
1505                         BTRFS_I(inode)->defrag_compress = compress_type;
1506                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1507                 if (ret < 0) {
1508                         inode_unlock(inode);
1509                         goto out_ra;
1510                 }
1511
1512                 defrag_count += ret;
1513                 balance_dirty_pages_ratelimited(inode->i_mapping);
1514                 inode_unlock(inode);
1515
1516                 if (newer_than) {
1517                         if (newer_off == (u64)-1)
1518                                 break;
1519
1520                         if (ret > 0)
1521                                 i += ret;
1522
1523                         newer_off = max(newer_off + 1,
1524                                         (u64)i << PAGE_SHIFT);
1525
1526                         ret = find_new_extents(root, inode, newer_than,
1527                                                &newer_off, SZ_64K);
1528                         if (!ret) {
1529                                 range->start = newer_off;
1530                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1531                         } else {
1532                                 break;
1533                         }
1534                 } else {
1535                         if (ret > 0) {
1536                                 i += ret;
1537                                 last_len += ret << PAGE_SHIFT;
1538                         } else {
1539                                 i++;
1540                                 last_len = 0;
1541                         }
1542                 }
1543         }
1544
1545         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1546                 filemap_flush(inode->i_mapping);
1547                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1548                              &BTRFS_I(inode)->runtime_flags))
1549                         filemap_flush(inode->i_mapping);
1550         }
1551
1552         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1553                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1554         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1555                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1556         }
1557
1558         ret = defrag_count;
1559
1560 out_ra:
1561         if (do_compress) {
1562                 inode_lock(inode);
1563                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1564                 inode_unlock(inode);
1565         }
1566         if (!file)
1567                 kfree(ra);
1568         kfree(pages);
1569         return ret;
1570 }
1571
1572 static noinline int btrfs_ioctl_resize(struct file *file,
1573                                         void __user *arg)
1574 {
1575         struct inode *inode = file_inode(file);
1576         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1577         u64 new_size;
1578         u64 old_size;
1579         u64 devid = 1;
1580         struct btrfs_root *root = BTRFS_I(inode)->root;
1581         struct btrfs_ioctl_vol_args *vol_args;
1582         struct btrfs_trans_handle *trans;
1583         struct btrfs_device *device = NULL;
1584         char *sizestr;
1585         char *retptr;
1586         char *devstr = NULL;
1587         int ret = 0;
1588         int mod = 0;
1589
1590         if (!capable(CAP_SYS_ADMIN))
1591                 return -EPERM;
1592
1593         ret = mnt_want_write_file(file);
1594         if (ret)
1595                 return ret;
1596
1597         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1598                 mnt_drop_write_file(file);
1599                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1600         }
1601
1602         vol_args = memdup_user(arg, sizeof(*vol_args));
1603         if (IS_ERR(vol_args)) {
1604                 ret = PTR_ERR(vol_args);
1605                 goto out;
1606         }
1607
1608         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1609
1610         sizestr = vol_args->name;
1611         devstr = strchr(sizestr, ':');
1612         if (devstr) {
1613                 sizestr = devstr + 1;
1614                 *devstr = '\0';
1615                 devstr = vol_args->name;
1616                 ret = kstrtoull(devstr, 10, &devid);
1617                 if (ret)
1618                         goto out_free;
1619                 if (!devid) {
1620                         ret = -EINVAL;
1621                         goto out_free;
1622                 }
1623                 btrfs_info(fs_info, "resizing devid %llu", devid);
1624         }
1625
1626         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1627         if (!device) {
1628                 btrfs_info(fs_info, "resizer unable to find device %llu",
1629                            devid);
1630                 ret = -ENODEV;
1631                 goto out_free;
1632         }
1633
1634         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1635                 btrfs_info(fs_info,
1636                            "resizer unable to apply on readonly device %llu",
1637                        devid);
1638                 ret = -EPERM;
1639                 goto out_free;
1640         }
1641
1642         if (!strcmp(sizestr, "max"))
1643                 new_size = device->bdev->bd_inode->i_size;
1644         else {
1645                 if (sizestr[0] == '-') {
1646                         mod = -1;
1647                         sizestr++;
1648                 } else if (sizestr[0] == '+') {
1649                         mod = 1;
1650                         sizestr++;
1651                 }
1652                 new_size = memparse(sizestr, &retptr);
1653                 if (*retptr != '\0' || new_size == 0) {
1654                         ret = -EINVAL;
1655                         goto out_free;
1656                 }
1657         }
1658
1659         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1660                 ret = -EPERM;
1661                 goto out_free;
1662         }
1663
1664         old_size = btrfs_device_get_total_bytes(device);
1665
1666         if (mod < 0) {
1667                 if (new_size > old_size) {
1668                         ret = -EINVAL;
1669                         goto out_free;
1670                 }
1671                 new_size = old_size - new_size;
1672         } else if (mod > 0) {
1673                 if (new_size > ULLONG_MAX - old_size) {
1674                         ret = -ERANGE;
1675                         goto out_free;
1676                 }
1677                 new_size = old_size + new_size;
1678         }
1679
1680         if (new_size < SZ_256M) {
1681                 ret = -EINVAL;
1682                 goto out_free;
1683         }
1684         if (new_size > device->bdev->bd_inode->i_size) {
1685                 ret = -EFBIG;
1686                 goto out_free;
1687         }
1688
1689         new_size = round_down(new_size, fs_info->sectorsize);
1690
1691         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1692                           rcu_str_deref(device->name), new_size);
1693
1694         if (new_size > old_size) {
1695                 trans = btrfs_start_transaction(root, 0);
1696                 if (IS_ERR(trans)) {
1697                         ret = PTR_ERR(trans);
1698                         goto out_free;
1699                 }
1700                 ret = btrfs_grow_device(trans, device, new_size);
1701                 btrfs_commit_transaction(trans);
1702         } else if (new_size < old_size) {
1703                 ret = btrfs_shrink_device(device, new_size);
1704         } /* equal, nothing need to do */
1705
1706 out_free:
1707         kfree(vol_args);
1708 out:
1709         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1710         mnt_drop_write_file(file);
1711         return ret;
1712 }
1713
1714 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1715                                 const char *name, unsigned long fd, int subvol,
1716                                 u64 *transid, bool readonly,
1717                                 struct btrfs_qgroup_inherit *inherit)
1718 {
1719         int namelen;
1720         int ret = 0;
1721
1722         if (!S_ISDIR(file_inode(file)->i_mode))
1723                 return -ENOTDIR;
1724
1725         ret = mnt_want_write_file(file);
1726         if (ret)
1727                 goto out;
1728
1729         namelen = strlen(name);
1730         if (strchr(name, '/')) {
1731                 ret = -EINVAL;
1732                 goto out_drop_write;
1733         }
1734
1735         if (name[0] == '.' &&
1736            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1737                 ret = -EEXIST;
1738                 goto out_drop_write;
1739         }
1740
1741         if (subvol) {
1742                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1743                                      NULL, transid, readonly, inherit);
1744         } else {
1745                 struct fd src = fdget(fd);
1746                 struct inode *src_inode;
1747                 if (!src.file) {
1748                         ret = -EINVAL;
1749                         goto out_drop_write;
1750                 }
1751
1752                 src_inode = file_inode(src.file);
1753                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1754                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1755                                    "Snapshot src from another FS");
1756                         ret = -EXDEV;
1757                 } else if (!inode_owner_or_capable(src_inode)) {
1758                         /*
1759                          * Subvolume creation is not restricted, but snapshots
1760                          * are limited to own subvolumes only
1761                          */
1762                         ret = -EPERM;
1763                 } else {
1764                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1765                                              BTRFS_I(src_inode)->root,
1766                                              transid, readonly, inherit);
1767                 }
1768                 fdput(src);
1769         }
1770 out_drop_write:
1771         mnt_drop_write_file(file);
1772 out:
1773         return ret;
1774 }
1775
1776 static noinline int btrfs_ioctl_snap_create(struct file *file,
1777                                             void __user *arg, int subvol)
1778 {
1779         struct btrfs_ioctl_vol_args *vol_args;
1780         int ret;
1781
1782         if (!S_ISDIR(file_inode(file)->i_mode))
1783                 return -ENOTDIR;
1784
1785         vol_args = memdup_user(arg, sizeof(*vol_args));
1786         if (IS_ERR(vol_args))
1787                 return PTR_ERR(vol_args);
1788         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1789
1790         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1791                                               vol_args->fd, subvol,
1792                                               NULL, false, NULL);
1793
1794         kfree(vol_args);
1795         return ret;
1796 }
1797
1798 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1799                                                void __user *arg, int subvol)
1800 {
1801         struct btrfs_ioctl_vol_args_v2 *vol_args;
1802         int ret;
1803         u64 transid = 0;
1804         u64 *ptr = NULL;
1805         bool readonly = false;
1806         struct btrfs_qgroup_inherit *inherit = NULL;
1807
1808         if (!S_ISDIR(file_inode(file)->i_mode))
1809                 return -ENOTDIR;
1810
1811         vol_args = memdup_user(arg, sizeof(*vol_args));
1812         if (IS_ERR(vol_args))
1813                 return PTR_ERR(vol_args);
1814         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1815
1816         if (vol_args->flags &
1817             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1818               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1819                 ret = -EOPNOTSUPP;
1820                 goto free_args;
1821         }
1822
1823         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1824                 ptr = &transid;
1825         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1826                 readonly = true;
1827         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1828                 if (vol_args->size > PAGE_SIZE) {
1829                         ret = -EINVAL;
1830                         goto free_args;
1831                 }
1832                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1833                 if (IS_ERR(inherit)) {
1834                         ret = PTR_ERR(inherit);
1835                         goto free_args;
1836                 }
1837         }
1838
1839         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1840                                               vol_args->fd, subvol, ptr,
1841                                               readonly, inherit);
1842         if (ret)
1843                 goto free_inherit;
1844
1845         if (ptr && copy_to_user(arg +
1846                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1847                                         transid),
1848                                 ptr, sizeof(*ptr)))
1849                 ret = -EFAULT;
1850
1851 free_inherit:
1852         kfree(inherit);
1853 free_args:
1854         kfree(vol_args);
1855         return ret;
1856 }
1857
1858 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1859                                                 void __user *arg)
1860 {
1861         struct inode *inode = file_inode(file);
1862         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1863         struct btrfs_root *root = BTRFS_I(inode)->root;
1864         int ret = 0;
1865         u64 flags = 0;
1866
1867         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1868                 return -EINVAL;
1869
1870         down_read(&fs_info->subvol_sem);
1871         if (btrfs_root_readonly(root))
1872                 flags |= BTRFS_SUBVOL_RDONLY;
1873         up_read(&fs_info->subvol_sem);
1874
1875         if (copy_to_user(arg, &flags, sizeof(flags)))
1876                 ret = -EFAULT;
1877
1878         return ret;
1879 }
1880
1881 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1882                                               void __user *arg)
1883 {
1884         struct inode *inode = file_inode(file);
1885         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1886         struct btrfs_root *root = BTRFS_I(inode)->root;
1887         struct btrfs_trans_handle *trans;
1888         u64 root_flags;
1889         u64 flags;
1890         int ret = 0;
1891
1892         if (!inode_owner_or_capable(inode))
1893                 return -EPERM;
1894
1895         ret = mnt_want_write_file(file);
1896         if (ret)
1897                 goto out;
1898
1899         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1900                 ret = -EINVAL;
1901                 goto out_drop_write;
1902         }
1903
1904         if (copy_from_user(&flags, arg, sizeof(flags))) {
1905                 ret = -EFAULT;
1906                 goto out_drop_write;
1907         }
1908
1909         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1910                 ret = -EINVAL;
1911                 goto out_drop_write;
1912         }
1913
1914         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1915                 ret = -EOPNOTSUPP;
1916                 goto out_drop_write;
1917         }
1918
1919         down_write(&fs_info->subvol_sem);
1920
1921         /* nothing to do */
1922         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1923                 goto out_drop_sem;
1924
1925         root_flags = btrfs_root_flags(&root->root_item);
1926         if (flags & BTRFS_SUBVOL_RDONLY) {
1927                 btrfs_set_root_flags(&root->root_item,
1928                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1929         } else {
1930                 /*
1931                  * Block RO -> RW transition if this subvolume is involved in
1932                  * send
1933                  */
1934                 spin_lock(&root->root_item_lock);
1935                 if (root->send_in_progress == 0) {
1936                         btrfs_set_root_flags(&root->root_item,
1937                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1938                         spin_unlock(&root->root_item_lock);
1939                 } else {
1940                         spin_unlock(&root->root_item_lock);
1941                         btrfs_warn(fs_info,
1942                                    "Attempt to set subvolume %llu read-write during send",
1943                                    root->root_key.objectid);
1944                         ret = -EPERM;
1945                         goto out_drop_sem;
1946                 }
1947         }
1948
1949         trans = btrfs_start_transaction(root, 1);
1950         if (IS_ERR(trans)) {
1951                 ret = PTR_ERR(trans);
1952                 goto out_reset;
1953         }
1954
1955         ret = btrfs_update_root(trans, fs_info->tree_root,
1956                                 &root->root_key, &root->root_item);
1957         if (ret < 0) {
1958                 btrfs_end_transaction(trans);
1959                 goto out_reset;
1960         }
1961
1962         ret = btrfs_commit_transaction(trans);
1963
1964 out_reset:
1965         if (ret)
1966                 btrfs_set_root_flags(&root->root_item, root_flags);
1967 out_drop_sem:
1968         up_write(&fs_info->subvol_sem);
1969 out_drop_write:
1970         mnt_drop_write_file(file);
1971 out:
1972         return ret;
1973 }
1974
1975 static noinline int key_in_sk(struct btrfs_key *key,
1976                               struct btrfs_ioctl_search_key *sk)
1977 {
1978         struct btrfs_key test;
1979         int ret;
1980
1981         test.objectid = sk->min_objectid;
1982         test.type = sk->min_type;
1983         test.offset = sk->min_offset;
1984
1985         ret = btrfs_comp_cpu_keys(key, &test);
1986         if (ret < 0)
1987                 return 0;
1988
1989         test.objectid = sk->max_objectid;
1990         test.type = sk->max_type;
1991         test.offset = sk->max_offset;
1992
1993         ret = btrfs_comp_cpu_keys(key, &test);
1994         if (ret > 0)
1995                 return 0;
1996         return 1;
1997 }
1998
1999 static noinline int copy_to_sk(struct btrfs_path *path,
2000                                struct btrfs_key *key,
2001                                struct btrfs_ioctl_search_key *sk,
2002                                size_t *buf_size,
2003                                char __user *ubuf,
2004                                unsigned long *sk_offset,
2005                                int *num_found)
2006 {
2007         u64 found_transid;
2008         struct extent_buffer *leaf;
2009         struct btrfs_ioctl_search_header sh;
2010         struct btrfs_key test;
2011         unsigned long item_off;
2012         unsigned long item_len;
2013         int nritems;
2014         int i;
2015         int slot;
2016         int ret = 0;
2017
2018         leaf = path->nodes[0];
2019         slot = path->slots[0];
2020         nritems = btrfs_header_nritems(leaf);
2021
2022         if (btrfs_header_generation(leaf) > sk->max_transid) {
2023                 i = nritems;
2024                 goto advance_key;
2025         }
2026         found_transid = btrfs_header_generation(leaf);
2027
2028         for (i = slot; i < nritems; i++) {
2029                 item_off = btrfs_item_ptr_offset(leaf, i);
2030                 item_len = btrfs_item_size_nr(leaf, i);
2031
2032                 btrfs_item_key_to_cpu(leaf, key, i);
2033                 if (!key_in_sk(key, sk))
2034                         continue;
2035
2036                 if (sizeof(sh) + item_len > *buf_size) {
2037                         if (*num_found) {
2038                                 ret = 1;
2039                                 goto out;
2040                         }
2041
2042                         /*
2043                          * return one empty item back for v1, which does not
2044                          * handle -EOVERFLOW
2045                          */
2046
2047                         *buf_size = sizeof(sh) + item_len;
2048                         item_len = 0;
2049                         ret = -EOVERFLOW;
2050                 }
2051
2052                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2053                         ret = 1;
2054                         goto out;
2055                 }
2056
2057                 sh.objectid = key->objectid;
2058                 sh.offset = key->offset;
2059                 sh.type = key->type;
2060                 sh.len = item_len;
2061                 sh.transid = found_transid;
2062
2063                 /* copy search result header */
2064                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2065                         ret = -EFAULT;
2066                         goto out;
2067                 }
2068
2069                 *sk_offset += sizeof(sh);
2070
2071                 if (item_len) {
2072                         char __user *up = ubuf + *sk_offset;
2073                         /* copy the item */
2074                         if (read_extent_buffer_to_user(leaf, up,
2075                                                        item_off, item_len)) {
2076                                 ret = -EFAULT;
2077                                 goto out;
2078                         }
2079
2080                         *sk_offset += item_len;
2081                 }
2082                 (*num_found)++;
2083
2084                 if (ret) /* -EOVERFLOW from above */
2085                         goto out;
2086
2087                 if (*num_found >= sk->nr_items) {
2088                         ret = 1;
2089                         goto out;
2090                 }
2091         }
2092 advance_key:
2093         ret = 0;
2094         test.objectid = sk->max_objectid;
2095         test.type = sk->max_type;
2096         test.offset = sk->max_offset;
2097         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2098                 ret = 1;
2099         else if (key->offset < (u64)-1)
2100                 key->offset++;
2101         else if (key->type < (u8)-1) {
2102                 key->offset = 0;
2103                 key->type++;
2104         } else if (key->objectid < (u64)-1) {
2105                 key->offset = 0;
2106                 key->type = 0;
2107                 key->objectid++;
2108         } else
2109                 ret = 1;
2110 out:
2111         /*
2112          *  0: all items from this leaf copied, continue with next
2113          *  1: * more items can be copied, but unused buffer is too small
2114          *     * all items were found
2115          *     Either way, it will stops the loop which iterates to the next
2116          *     leaf
2117          *  -EOVERFLOW: item was to large for buffer
2118          *  -EFAULT: could not copy extent buffer back to userspace
2119          */
2120         return ret;
2121 }
2122
2123 static noinline int search_ioctl(struct inode *inode,
2124                                  struct btrfs_ioctl_search_key *sk,
2125                                  size_t *buf_size,
2126                                  char __user *ubuf)
2127 {
2128         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2129         struct btrfs_root *root;
2130         struct btrfs_key key;
2131         struct btrfs_path *path;
2132         int ret;
2133         int num_found = 0;
2134         unsigned long sk_offset = 0;
2135
2136         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2137                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2138                 return -EOVERFLOW;
2139         }
2140
2141         path = btrfs_alloc_path();
2142         if (!path)
2143                 return -ENOMEM;
2144
2145         if (sk->tree_id == 0) {
2146                 /* search the root of the inode that was passed */
2147                 root = BTRFS_I(inode)->root;
2148         } else {
2149                 key.objectid = sk->tree_id;
2150                 key.type = BTRFS_ROOT_ITEM_KEY;
2151                 key.offset = (u64)-1;
2152                 root = btrfs_read_fs_root_no_name(info, &key);
2153                 if (IS_ERR(root)) {
2154                         btrfs_free_path(path);
2155                         return PTR_ERR(root);
2156                 }
2157         }
2158
2159         key.objectid = sk->min_objectid;
2160         key.type = sk->min_type;
2161         key.offset = sk->min_offset;
2162
2163         while (1) {
2164                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2165                 if (ret != 0) {
2166                         if (ret > 0)
2167                                 ret = 0;
2168                         goto err;
2169                 }
2170                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2171                                  &sk_offset, &num_found);
2172                 btrfs_release_path(path);
2173                 if (ret)
2174                         break;
2175
2176         }
2177         if (ret > 0)
2178                 ret = 0;
2179 err:
2180         sk->nr_items = num_found;
2181         btrfs_free_path(path);
2182         return ret;
2183 }
2184
2185 static noinline int btrfs_ioctl_tree_search(struct file *file,
2186                                            void __user *argp)
2187 {
2188         struct btrfs_ioctl_search_args __user *uargs;
2189         struct btrfs_ioctl_search_key sk;
2190         struct inode *inode;
2191         int ret;
2192         size_t buf_size;
2193
2194         if (!capable(CAP_SYS_ADMIN))
2195                 return -EPERM;
2196
2197         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2198
2199         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2200                 return -EFAULT;
2201
2202         buf_size = sizeof(uargs->buf);
2203
2204         inode = file_inode(file);
2205         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2206
2207         /*
2208          * In the origin implementation an overflow is handled by returning a
2209          * search header with a len of zero, so reset ret.
2210          */
2211         if (ret == -EOVERFLOW)
2212                 ret = 0;
2213
2214         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2215                 ret = -EFAULT;
2216         return ret;
2217 }
2218
2219 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2220                                                void __user *argp)
2221 {
2222         struct btrfs_ioctl_search_args_v2 __user *uarg;
2223         struct btrfs_ioctl_search_args_v2 args;
2224         struct inode *inode;
2225         int ret;
2226         size_t buf_size;
2227         const size_t buf_limit = SZ_16M;
2228
2229         if (!capable(CAP_SYS_ADMIN))
2230                 return -EPERM;
2231
2232         /* copy search header and buffer size */
2233         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2234         if (copy_from_user(&args, uarg, sizeof(args)))
2235                 return -EFAULT;
2236
2237         buf_size = args.buf_size;
2238
2239         /* limit result size to 16MB */
2240         if (buf_size > buf_limit)
2241                 buf_size = buf_limit;
2242
2243         inode = file_inode(file);
2244         ret = search_ioctl(inode, &args.key, &buf_size,
2245                            (char __user *)(&uarg->buf[0]));
2246         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2247                 ret = -EFAULT;
2248         else if (ret == -EOVERFLOW &&
2249                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2250                 ret = -EFAULT;
2251
2252         return ret;
2253 }
2254
2255 /*
2256  * Search INODE_REFs to identify path name of 'dirid' directory
2257  * in a 'tree_id' tree. and sets path name to 'name'.
2258  */
2259 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2260                                 u64 tree_id, u64 dirid, char *name)
2261 {
2262         struct btrfs_root *root;
2263         struct btrfs_key key;
2264         char *ptr;
2265         int ret = -1;
2266         int slot;
2267         int len;
2268         int total_len = 0;
2269         struct btrfs_inode_ref *iref;
2270         struct extent_buffer *l;
2271         struct btrfs_path *path;
2272
2273         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2274                 name[0]='\0';
2275                 return 0;
2276         }
2277
2278         path = btrfs_alloc_path();
2279         if (!path)
2280                 return -ENOMEM;
2281
2282         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2283
2284         key.objectid = tree_id;
2285         key.type = BTRFS_ROOT_ITEM_KEY;
2286         key.offset = (u64)-1;
2287         root = btrfs_read_fs_root_no_name(info, &key);
2288         if (IS_ERR(root)) {
2289                 ret = PTR_ERR(root);
2290                 goto out;
2291         }
2292
2293         key.objectid = dirid;
2294         key.type = BTRFS_INODE_REF_KEY;
2295         key.offset = (u64)-1;
2296
2297         while (1) {
2298                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2299                 if (ret < 0)
2300                         goto out;
2301                 else if (ret > 0) {
2302                         ret = btrfs_previous_item(root, path, dirid,
2303                                                   BTRFS_INODE_REF_KEY);
2304                         if (ret < 0)
2305                                 goto out;
2306                         else if (ret > 0) {
2307                                 ret = -ENOENT;
2308                                 goto out;
2309                         }
2310                 }
2311
2312                 l = path->nodes[0];
2313                 slot = path->slots[0];
2314                 btrfs_item_key_to_cpu(l, &key, slot);
2315
2316                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2317                 len = btrfs_inode_ref_name_len(l, iref);
2318                 ptr -= len + 1;
2319                 total_len += len + 1;
2320                 if (ptr < name) {
2321                         ret = -ENAMETOOLONG;
2322                         goto out;
2323                 }
2324
2325                 *(ptr + len) = '/';
2326                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2327
2328                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2329                         break;
2330
2331                 btrfs_release_path(path);
2332                 key.objectid = key.offset;
2333                 key.offset = (u64)-1;
2334                 dirid = key.objectid;
2335         }
2336         memmove(name, ptr, total_len);
2337         name[total_len] = '\0';
2338         ret = 0;
2339 out:
2340         btrfs_free_path(path);
2341         return ret;
2342 }
2343
2344 static int btrfs_search_path_in_tree_user(struct inode *inode,
2345                                 struct btrfs_ioctl_ino_lookup_user_args *args)
2346 {
2347         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2348         struct super_block *sb = inode->i_sb;
2349         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2350         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2351         u64 dirid = args->dirid;
2352         unsigned long item_off;
2353         unsigned long item_len;
2354         struct btrfs_inode_ref *iref;
2355         struct btrfs_root_ref *rref;
2356         struct btrfs_root *root;
2357         struct btrfs_path *path;
2358         struct btrfs_key key, key2;
2359         struct extent_buffer *leaf;
2360         struct inode *temp_inode;
2361         char *ptr;
2362         int slot;
2363         int len;
2364         int total_len = 0;
2365         int ret;
2366
2367         path = btrfs_alloc_path();
2368         if (!path)
2369                 return -ENOMEM;
2370
2371         /*
2372          * If the bottom subvolume does not exist directly under upper_limit,
2373          * construct the path in from the bottom up.
2374          */
2375         if (dirid != upper_limit.objectid) {
2376                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2377
2378                 key.objectid = treeid;
2379                 key.type = BTRFS_ROOT_ITEM_KEY;
2380                 key.offset = (u64)-1;
2381                 root = btrfs_read_fs_root_no_name(fs_info, &key);
2382                 if (IS_ERR(root)) {
2383                         ret = PTR_ERR(root);
2384                         goto out;
2385                 }
2386
2387                 key.objectid = dirid;
2388                 key.type = BTRFS_INODE_REF_KEY;
2389                 key.offset = (u64)-1;
2390                 while (1) {
2391                         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2392                         if (ret < 0) {
2393                                 goto out;
2394                         } else if (ret > 0) {
2395                                 ret = btrfs_previous_item(root, path, dirid,
2396                                                           BTRFS_INODE_REF_KEY);
2397                                 if (ret < 0) {
2398                                         goto out;
2399                                 } else if (ret > 0) {
2400                                         ret = -ENOENT;
2401                                         goto out;
2402                                 }
2403                         }
2404
2405                         leaf = path->nodes[0];
2406                         slot = path->slots[0];
2407                         btrfs_item_key_to_cpu(leaf, &key, slot);
2408
2409                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2410                         len = btrfs_inode_ref_name_len(leaf, iref);
2411                         ptr -= len + 1;
2412                         total_len += len + 1;
2413                         if (ptr < args->path) {
2414                                 ret = -ENAMETOOLONG;
2415                                 goto out;
2416                         }
2417
2418                         *(ptr + len) = '/';
2419                         read_extent_buffer(leaf, ptr,
2420                                         (unsigned long)(iref + 1), len);
2421
2422                         /* Check the read+exec permission of this directory */
2423                         ret = btrfs_previous_item(root, path, dirid,
2424                                                   BTRFS_INODE_ITEM_KEY);
2425                         if (ret < 0) {
2426                                 goto out;
2427                         } else if (ret > 0) {
2428                                 ret = -ENOENT;
2429                                 goto out;
2430                         }
2431
2432                         leaf = path->nodes[0];
2433                         slot = path->slots[0];
2434                         btrfs_item_key_to_cpu(leaf, &key2, slot);
2435                         if (key2.objectid != dirid) {
2436                                 ret = -ENOENT;
2437                                 goto out;
2438                         }
2439
2440                         temp_inode = btrfs_iget(sb, &key2, root, NULL);
2441                         if (IS_ERR(temp_inode)) {
2442                                 ret = PTR_ERR(temp_inode);
2443                                 goto out;
2444                         }
2445                         ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2446                         iput(temp_inode);
2447                         if (ret) {
2448                                 ret = -EACCES;
2449                                 goto out;
2450                         }
2451
2452                         if (key.offset == upper_limit.objectid)
2453                                 break;
2454                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2455                                 ret = -EACCES;
2456                                 goto out;
2457                         }
2458
2459                         btrfs_release_path(path);
2460                         key.objectid = key.offset;
2461                         key.offset = (u64)-1;
2462                         dirid = key.objectid;
2463                 }
2464
2465                 memmove(args->path, ptr, total_len);
2466                 args->path[total_len] = '\0';
2467                 btrfs_release_path(path);
2468         }
2469
2470         /* Get the bottom subvolume's name from ROOT_REF */
2471         root = fs_info->tree_root;
2472         key.objectid = treeid;
2473         key.type = BTRFS_ROOT_REF_KEY;
2474         key.offset = args->treeid;
2475         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2476         if (ret < 0) {
2477                 goto out;
2478         } else if (ret > 0) {
2479                 ret = -ENOENT;
2480                 goto out;
2481         }
2482
2483         leaf = path->nodes[0];
2484         slot = path->slots[0];
2485         btrfs_item_key_to_cpu(leaf, &key, slot);
2486
2487         item_off = btrfs_item_ptr_offset(leaf, slot);
2488         item_len = btrfs_item_size_nr(leaf, slot);
2489         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2490         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2491         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2492                 ret = -EINVAL;
2493                 goto out;
2494         }
2495
2496         /* Copy subvolume's name */
2497         item_off += sizeof(struct btrfs_root_ref);
2498         item_len -= sizeof(struct btrfs_root_ref);
2499         read_extent_buffer(leaf, args->name, item_off, item_len);
2500         args->name[item_len] = 0;
2501
2502 out:
2503         btrfs_free_path(path);
2504         return ret;
2505 }
2506
2507 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2508                                            void __user *argp)
2509 {
2510          struct btrfs_ioctl_ino_lookup_args *args;
2511          struct inode *inode;
2512         int ret = 0;
2513
2514         args = memdup_user(argp, sizeof(*args));
2515         if (IS_ERR(args))
2516                 return PTR_ERR(args);
2517
2518         inode = file_inode(file);
2519
2520         /*
2521          * Unprivileged query to obtain the containing subvolume root id. The
2522          * path is reset so it's consistent with btrfs_search_path_in_tree.
2523          */
2524         if (args->treeid == 0)
2525                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2526
2527         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2528                 args->name[0] = 0;
2529                 goto out;
2530         }
2531
2532         if (!capable(CAP_SYS_ADMIN)) {
2533                 ret = -EPERM;
2534                 goto out;
2535         }
2536
2537         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2538                                         args->treeid, args->objectid,
2539                                         args->name);
2540
2541 out:
2542         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2543                 ret = -EFAULT;
2544
2545         kfree(args);
2546         return ret;
2547 }
2548
2549 /*
2550  * Version of ino_lookup ioctl (unprivileged)
2551  *
2552  * The main differences from ino_lookup ioctl are:
2553  *
2554  *   1. Read + Exec permission will be checked using inode_permission() during
2555  *      path construction. -EACCES will be returned in case of failure.
2556  *   2. Path construction will be stopped at the inode number which corresponds
2557  *      to the fd with which this ioctl is called. If constructed path does not
2558  *      exist under fd's inode, -EACCES will be returned.
2559  *   3. The name of bottom subvolume is also searched and filled.
2560  */
2561 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2562 {
2563         struct btrfs_ioctl_ino_lookup_user_args *args;
2564         struct inode *inode;
2565         int ret;
2566
2567         args = memdup_user(argp, sizeof(*args));
2568         if (IS_ERR(args))
2569                 return PTR_ERR(args);
2570
2571         inode = file_inode(file);
2572
2573         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2574             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2575                 /*
2576                  * The subvolume does not exist under fd with which this is
2577                  * called
2578                  */
2579                 kfree(args);
2580                 return -EACCES;
2581         }
2582
2583         ret = btrfs_search_path_in_tree_user(inode, args);
2584
2585         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2586                 ret = -EFAULT;
2587
2588         kfree(args);
2589         return ret;
2590 }
2591
2592 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2593 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2594 {
2595         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2596         struct btrfs_fs_info *fs_info;
2597         struct btrfs_root *root;
2598         struct btrfs_path *path;
2599         struct btrfs_key key;
2600         struct btrfs_root_item *root_item;
2601         struct btrfs_root_ref *rref;
2602         struct extent_buffer *leaf;
2603         unsigned long item_off;
2604         unsigned long item_len;
2605         struct inode *inode;
2606         int slot;
2607         int ret = 0;
2608
2609         path = btrfs_alloc_path();
2610         if (!path)
2611                 return -ENOMEM;
2612
2613         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2614         if (!subvol_info) {
2615                 btrfs_free_path(path);
2616                 return -ENOMEM;
2617         }
2618
2619         inode = file_inode(file);
2620         fs_info = BTRFS_I(inode)->root->fs_info;
2621
2622         /* Get root_item of inode's subvolume */
2623         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2624         key.type = BTRFS_ROOT_ITEM_KEY;
2625         key.offset = (u64)-1;
2626         root = btrfs_read_fs_root_no_name(fs_info, &key);
2627         if (IS_ERR(root)) {
2628                 ret = PTR_ERR(root);
2629                 goto out;
2630         }
2631         root_item = &root->root_item;
2632
2633         subvol_info->treeid = key.objectid;
2634
2635         subvol_info->generation = btrfs_root_generation(root_item);
2636         subvol_info->flags = btrfs_root_flags(root_item);
2637
2638         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2639         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2640                                                     BTRFS_UUID_SIZE);
2641         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2642                                                     BTRFS_UUID_SIZE);
2643
2644         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2645         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2646         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2647
2648         subvol_info->otransid = btrfs_root_otransid(root_item);
2649         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2650         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2651
2652         subvol_info->stransid = btrfs_root_stransid(root_item);
2653         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2654         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2655
2656         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2657         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2658         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2659
2660         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2661                 /* Search root tree for ROOT_BACKREF of this subvolume */
2662                 root = fs_info->tree_root;
2663
2664                 key.type = BTRFS_ROOT_BACKREF_KEY;
2665                 key.offset = 0;
2666                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2667                 if (ret < 0) {
2668                         goto out;
2669                 } else if (path->slots[0] >=
2670                            btrfs_header_nritems(path->nodes[0])) {
2671                         ret = btrfs_next_leaf(root, path);
2672                         if (ret < 0) {
2673                                 goto out;
2674                         } else if (ret > 0) {
2675                                 ret = -EUCLEAN;
2676                                 goto out;
2677                         }
2678                 }
2679
2680                 leaf = path->nodes[0];
2681                 slot = path->slots[0];
2682                 btrfs_item_key_to_cpu(leaf, &key, slot);
2683                 if (key.objectid == subvol_info->treeid &&
2684                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2685                         subvol_info->parent_id = key.offset;
2686
2687                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2688                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2689
2690                         item_off = btrfs_item_ptr_offset(leaf, slot)
2691                                         + sizeof(struct btrfs_root_ref);
2692                         item_len = btrfs_item_size_nr(leaf, slot)
2693                                         - sizeof(struct btrfs_root_ref);
2694                         read_extent_buffer(leaf, subvol_info->name,
2695                                            item_off, item_len);
2696                 } else {
2697                         ret = -ENOENT;
2698                         goto out;
2699                 }
2700         }
2701
2702         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2703                 ret = -EFAULT;
2704
2705 out:
2706         btrfs_free_path(path);
2707         kzfree(subvol_info);
2708         return ret;
2709 }
2710
2711 /*
2712  * Return ROOT_REF information of the subvolume containing this inode
2713  * except the subvolume name.
2714  */
2715 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2716 {
2717         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2718         struct btrfs_root_ref *rref;
2719         struct btrfs_root *root;
2720         struct btrfs_path *path;
2721         struct btrfs_key key;
2722         struct extent_buffer *leaf;
2723         struct inode *inode;
2724         u64 objectid;
2725         int slot;
2726         int ret;
2727         u8 found;
2728
2729         path = btrfs_alloc_path();
2730         if (!path)
2731                 return -ENOMEM;
2732
2733         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2734         if (IS_ERR(rootrefs)) {
2735                 btrfs_free_path(path);
2736                 return PTR_ERR(rootrefs);
2737         }
2738
2739         inode = file_inode(file);
2740         root = BTRFS_I(inode)->root->fs_info->tree_root;
2741         objectid = BTRFS_I(inode)->root->root_key.objectid;
2742
2743         key.objectid = objectid;
2744         key.type = BTRFS_ROOT_REF_KEY;
2745         key.offset = rootrefs->min_treeid;
2746         found = 0;
2747
2748         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2749         if (ret < 0) {
2750                 goto out;
2751         } else if (path->slots[0] >=
2752                    btrfs_header_nritems(path->nodes[0])) {
2753                 ret = btrfs_next_leaf(root, path);
2754                 if (ret < 0) {
2755                         goto out;
2756                 } else if (ret > 0) {
2757                         ret = -EUCLEAN;
2758                         goto out;
2759                 }
2760         }
2761         while (1) {
2762                 leaf = path->nodes[0];
2763                 slot = path->slots[0];
2764
2765                 btrfs_item_key_to_cpu(leaf, &key, slot);
2766                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2767                         ret = 0;
2768                         goto out;
2769                 }
2770
2771                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2772                         ret = -EOVERFLOW;
2773                         goto out;
2774                 }
2775
2776                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2777                 rootrefs->rootref[found].treeid = key.offset;
2778                 rootrefs->rootref[found].dirid =
2779                                   btrfs_root_ref_dirid(leaf, rref);
2780                 found++;
2781
2782                 ret = btrfs_next_item(root, path);
2783                 if (ret < 0) {
2784                         goto out;
2785                 } else if (ret > 0) {
2786                         ret = -EUCLEAN;
2787                         goto out;
2788                 }
2789         }
2790
2791 out:
2792         if (!ret || ret == -EOVERFLOW) {
2793                 rootrefs->num_items = found;
2794                 /* update min_treeid for next search */
2795                 if (found)
2796                         rootrefs->min_treeid =
2797                                 rootrefs->rootref[found - 1].treeid + 1;
2798                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2799                         ret = -EFAULT;
2800         }
2801
2802         kfree(rootrefs);
2803         btrfs_free_path(path);
2804
2805         return ret;
2806 }
2807
2808 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2809                                              void __user *arg)
2810 {
2811         struct dentry *parent = file->f_path.dentry;
2812         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2813         struct dentry *dentry;
2814         struct inode *dir = d_inode(parent);
2815         struct inode *inode;
2816         struct btrfs_root *root = BTRFS_I(dir)->root;
2817         struct btrfs_root *dest = NULL;
2818         struct btrfs_ioctl_vol_args *vol_args;
2819         int namelen;
2820         int err = 0;
2821
2822         if (!S_ISDIR(dir->i_mode))
2823                 return -ENOTDIR;
2824
2825         vol_args = memdup_user(arg, sizeof(*vol_args));
2826         if (IS_ERR(vol_args))
2827                 return PTR_ERR(vol_args);
2828
2829         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2830         namelen = strlen(vol_args->name);
2831         if (strchr(vol_args->name, '/') ||
2832             strncmp(vol_args->name, "..", namelen) == 0) {
2833                 err = -EINVAL;
2834                 goto out;
2835         }
2836
2837         err = mnt_want_write_file(file);
2838         if (err)
2839                 goto out;
2840
2841
2842         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2843         if (err == -EINTR)
2844                 goto out_drop_write;
2845         dentry = lookup_one_len(vol_args->name, parent, namelen);
2846         if (IS_ERR(dentry)) {
2847                 err = PTR_ERR(dentry);
2848                 goto out_unlock_dir;
2849         }
2850
2851         if (d_really_is_negative(dentry)) {
2852                 err = -ENOENT;
2853                 goto out_dput;
2854         }
2855
2856         inode = d_inode(dentry);
2857         dest = BTRFS_I(inode)->root;
2858         if (!capable(CAP_SYS_ADMIN)) {
2859                 /*
2860                  * Regular user.  Only allow this with a special mount
2861                  * option, when the user has write+exec access to the
2862                  * subvol root, and when rmdir(2) would have been
2863                  * allowed.
2864                  *
2865                  * Note that this is _not_ check that the subvol is
2866                  * empty or doesn't contain data that we wouldn't
2867                  * otherwise be able to delete.
2868                  *
2869                  * Users who want to delete empty subvols should try
2870                  * rmdir(2).
2871                  */
2872                 err = -EPERM;
2873                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2874                         goto out_dput;
2875
2876                 /*
2877                  * Do not allow deletion if the parent dir is the same
2878                  * as the dir to be deleted.  That means the ioctl
2879                  * must be called on the dentry referencing the root
2880                  * of the subvol, not a random directory contained
2881                  * within it.
2882                  */
2883                 err = -EINVAL;
2884                 if (root == dest)
2885                         goto out_dput;
2886
2887                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2888                 if (err)
2889                         goto out_dput;
2890         }
2891
2892         /* check if subvolume may be deleted by a user */
2893         err = btrfs_may_delete(dir, dentry, 1);
2894         if (err)
2895                 goto out_dput;
2896
2897         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2898                 err = -EINVAL;
2899                 goto out_dput;
2900         }
2901
2902         inode_lock(inode);
2903         err = btrfs_delete_subvolume(dir, dentry);
2904         inode_unlock(inode);
2905         if (!err)
2906                 d_delete(dentry);
2907
2908 out_dput:
2909         dput(dentry);
2910 out_unlock_dir:
2911         inode_unlock(dir);
2912 out_drop_write:
2913         mnt_drop_write_file(file);
2914 out:
2915         kfree(vol_args);
2916         return err;
2917 }
2918
2919 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2920 {
2921         struct inode *inode = file_inode(file);
2922         struct btrfs_root *root = BTRFS_I(inode)->root;
2923         struct btrfs_ioctl_defrag_range_args *range;
2924         int ret;
2925
2926         ret = mnt_want_write_file(file);
2927         if (ret)
2928                 return ret;
2929
2930         if (btrfs_root_readonly(root)) {
2931                 ret = -EROFS;
2932                 goto out;
2933         }
2934
2935         switch (inode->i_mode & S_IFMT) {
2936         case S_IFDIR:
2937                 if (!capable(CAP_SYS_ADMIN)) {
2938                         ret = -EPERM;
2939                         goto out;
2940                 }
2941                 ret = btrfs_defrag_root(root);
2942                 break;
2943         case S_IFREG:
2944                 if (!(file->f_mode & FMODE_WRITE)) {
2945                         ret = -EINVAL;
2946                         goto out;
2947                 }
2948
2949                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2950                 if (!range) {
2951                         ret = -ENOMEM;
2952                         goto out;
2953                 }
2954
2955                 if (argp) {
2956                         if (copy_from_user(range, argp,
2957                                            sizeof(*range))) {
2958                                 ret = -EFAULT;
2959                                 kfree(range);
2960                                 goto out;
2961                         }
2962                         /* compression requires us to start the IO */
2963                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2964                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2965                                 range->extent_thresh = (u32)-1;
2966                         }
2967                 } else {
2968                         /* the rest are all set to zero by kzalloc */
2969                         range->len = (u64)-1;
2970                 }
2971                 ret = btrfs_defrag_file(file_inode(file), file,
2972                                         range, BTRFS_OLDEST_GENERATION, 0);
2973                 if (ret > 0)
2974                         ret = 0;
2975                 kfree(range);
2976                 break;
2977         default:
2978                 ret = -EINVAL;
2979         }
2980 out:
2981         mnt_drop_write_file(file);
2982         return ret;
2983 }
2984
2985 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2986 {
2987         struct btrfs_ioctl_vol_args *vol_args;
2988         int ret;
2989
2990         if (!capable(CAP_SYS_ADMIN))
2991                 return -EPERM;
2992
2993         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
2994                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2995
2996         vol_args = memdup_user(arg, sizeof(*vol_args));
2997         if (IS_ERR(vol_args)) {
2998                 ret = PTR_ERR(vol_args);
2999                 goto out;
3000         }
3001
3002         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3003         ret = btrfs_init_new_device(fs_info, vol_args->name);
3004
3005         if (!ret)
3006                 btrfs_info(fs_info, "disk added %s", vol_args->name);
3007
3008         kfree(vol_args);
3009 out:
3010         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3011         return ret;
3012 }
3013
3014 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3015 {
3016         struct inode *inode = file_inode(file);
3017         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3018         struct btrfs_ioctl_vol_args_v2 *vol_args;
3019         int ret;
3020
3021         if (!capable(CAP_SYS_ADMIN))
3022                 return -EPERM;
3023
3024         ret = mnt_want_write_file(file);
3025         if (ret)
3026                 return ret;
3027
3028         vol_args = memdup_user(arg, sizeof(*vol_args));
3029         if (IS_ERR(vol_args)) {
3030                 ret = PTR_ERR(vol_args);
3031                 goto err_drop;
3032         }
3033
3034         /* Check for compatibility reject unknown flags */
3035         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3036                 ret = -EOPNOTSUPP;
3037                 goto out;
3038         }
3039
3040         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3041                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3042                 goto out;
3043         }
3044
3045         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3046                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3047         } else {
3048                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3049                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3050         }
3051         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3052
3053         if (!ret) {
3054                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3055                         btrfs_info(fs_info, "device deleted: id %llu",
3056                                         vol_args->devid);
3057                 else
3058                         btrfs_info(fs_info, "device deleted: %s",
3059                                         vol_args->name);
3060         }
3061 out:
3062         kfree(vol_args);
3063 err_drop:
3064         mnt_drop_write_file(file);
3065         return ret;
3066 }
3067
3068 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3069 {
3070         struct inode *inode = file_inode(file);
3071         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3072         struct btrfs_ioctl_vol_args *vol_args;
3073         int ret;
3074
3075         if (!capable(CAP_SYS_ADMIN))
3076                 return -EPERM;
3077
3078         ret = mnt_want_write_file(file);
3079         if (ret)
3080                 return ret;
3081
3082         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3083                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3084                 goto out_drop_write;
3085         }
3086
3087         vol_args = memdup_user(arg, sizeof(*vol_args));
3088         if (IS_ERR(vol_args)) {
3089                 ret = PTR_ERR(vol_args);
3090                 goto out;
3091         }
3092
3093         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3094         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3095
3096         if (!ret)
3097                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3098         kfree(vol_args);
3099 out:
3100         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3101 out_drop_write:
3102         mnt_drop_write_file(file);
3103
3104         return ret;
3105 }
3106
3107 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3108                                 void __user *arg)
3109 {
3110         struct btrfs_ioctl_fs_info_args *fi_args;
3111         struct btrfs_device *device;
3112         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3113         int ret = 0;
3114
3115         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3116         if (!fi_args)
3117                 return -ENOMEM;
3118
3119         rcu_read_lock();
3120         fi_args->num_devices = fs_devices->num_devices;
3121
3122         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3123                 if (device->devid > fi_args->max_id)
3124                         fi_args->max_id = device->devid;
3125         }
3126         rcu_read_unlock();
3127
3128         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
3129         fi_args->nodesize = fs_info->nodesize;
3130         fi_args->sectorsize = fs_info->sectorsize;
3131         fi_args->clone_alignment = fs_info->sectorsize;
3132
3133         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3134                 ret = -EFAULT;
3135
3136         kfree(fi_args);
3137         return ret;
3138 }
3139
3140 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3141                                  void __user *arg)
3142 {
3143         struct btrfs_ioctl_dev_info_args *di_args;
3144         struct btrfs_device *dev;
3145         int ret = 0;
3146         char *s_uuid = NULL;
3147
3148         di_args = memdup_user(arg, sizeof(*di_args));
3149         if (IS_ERR(di_args))
3150                 return PTR_ERR(di_args);
3151
3152         if (!btrfs_is_empty_uuid(di_args->uuid))
3153                 s_uuid = di_args->uuid;
3154
3155         rcu_read_lock();
3156         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
3157
3158         if (!dev) {
3159                 ret = -ENODEV;
3160                 goto out;
3161         }
3162
3163         di_args->devid = dev->devid;
3164         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3165         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3166         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3167         if (dev->name) {
3168                 struct rcu_string *name;
3169
3170                 name = rcu_dereference(dev->name);
3171                 strncpy(di_args->path, name->str, sizeof(di_args->path) - 1);
3172                 di_args->path[sizeof(di_args->path) - 1] = 0;
3173         } else {
3174                 di_args->path[0] = '\0';
3175         }
3176
3177 out:
3178         rcu_read_unlock();
3179         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3180                 ret = -EFAULT;
3181
3182         kfree(di_args);
3183         return ret;
3184 }
3185
3186 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
3187 {
3188         struct page *page;
3189
3190         page = grab_cache_page(inode->i_mapping, index);
3191         if (!page)
3192                 return ERR_PTR(-ENOMEM);
3193
3194         if (!PageUptodate(page)) {
3195                 int ret;
3196
3197                 ret = btrfs_readpage(NULL, page);
3198                 if (ret)
3199                         return ERR_PTR(ret);
3200                 lock_page(page);
3201                 if (!PageUptodate(page)) {
3202                         unlock_page(page);
3203                         put_page(page);
3204                         return ERR_PTR(-EIO);
3205                 }
3206                 if (page->mapping != inode->i_mapping) {
3207                         unlock_page(page);
3208                         put_page(page);
3209                         return ERR_PTR(-EAGAIN);
3210                 }
3211         }
3212
3213         return page;
3214 }
3215
3216 static int gather_extent_pages(struct inode *inode, struct page **pages,
3217                                int num_pages, u64 off)
3218 {
3219         int i;
3220         pgoff_t index = off >> PAGE_SHIFT;
3221
3222         for (i = 0; i < num_pages; i++) {
3223 again:
3224                 pages[i] = extent_same_get_page(inode, index + i);
3225                 if (IS_ERR(pages[i])) {
3226                         int err = PTR_ERR(pages[i]);
3227
3228                         if (err == -EAGAIN)
3229                                 goto again;
3230                         pages[i] = NULL;
3231                         return err;
3232                 }
3233         }
3234         return 0;
3235 }
3236
3237 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
3238                              bool retry_range_locking)
3239 {
3240         /*
3241          * Do any pending delalloc/csum calculations on inode, one way or
3242          * another, and lock file content.
3243          * The locking order is:
3244          *
3245          *   1) pages
3246          *   2) range in the inode's io tree
3247          */
3248         while (1) {
3249                 struct btrfs_ordered_extent *ordered;
3250                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3251                 ordered = btrfs_lookup_first_ordered_extent(inode,
3252                                                             off + len - 1);
3253                 if ((!ordered ||
3254                      ordered->file_offset + ordered->len <= off ||
3255                      ordered->file_offset >= off + len) &&
3256                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
3257                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
3258                         if (ordered)
3259                                 btrfs_put_ordered_extent(ordered);
3260                         break;
3261                 }
3262                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3263                 if (ordered)
3264                         btrfs_put_ordered_extent(ordered);
3265                 if (!retry_range_locking)
3266                         return -EAGAIN;
3267                 btrfs_wait_ordered_range(inode, off, len);
3268         }
3269         return 0;
3270 }
3271
3272 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
3273 {
3274         inode_unlock(inode1);
3275         inode_unlock(inode2);
3276 }
3277
3278 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
3279 {
3280         if (inode1 < inode2)
3281                 swap(inode1, inode2);
3282
3283         inode_lock_nested(inode1, I_MUTEX_PARENT);
3284         inode_lock_nested(inode2, I_MUTEX_CHILD);
3285 }
3286
3287 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
3288                                       struct inode *inode2, u64 loff2, u64 len)
3289 {
3290         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3291         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3292 }
3293
3294 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
3295                                     struct inode *inode2, u64 loff2, u64 len,
3296                                     bool retry_range_locking)
3297 {
3298         int ret;
3299
3300         if (inode1 < inode2) {
3301                 swap(inode1, inode2);
3302                 swap(loff1, loff2);
3303         }
3304         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
3305         if (ret)
3306                 return ret;
3307         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
3308         if (ret)
3309                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
3310                               loff1 + len - 1);
3311         return ret;
3312 }
3313
3314 struct cmp_pages {
3315         int             num_pages;
3316         struct page     **src_pages;
3317         struct page     **dst_pages;
3318 };
3319
3320 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
3321 {
3322         int i;
3323         struct page *pg;
3324
3325         for (i = 0; i < cmp->num_pages; i++) {
3326                 pg = cmp->src_pages[i];
3327                 if (pg) {
3328                         unlock_page(pg);
3329                         put_page(pg);
3330                         cmp->src_pages[i] = NULL;
3331                 }
3332                 pg = cmp->dst_pages[i];
3333                 if (pg) {
3334                         unlock_page(pg);
3335                         put_page(pg);
3336                         cmp->dst_pages[i] = NULL;
3337                 }
3338         }
3339 }
3340
3341 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3342                                   struct inode *dst, u64 dst_loff,
3343                                   u64 len, struct cmp_pages *cmp)
3344 {
3345         int ret;
3346         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3347
3348         cmp->num_pages = num_pages;
3349
3350         ret = gather_extent_pages(src, cmp->src_pages, num_pages, loff);
3351         if (ret)
3352                 goto out;
3353
3354         ret = gather_extent_pages(dst, cmp->dst_pages, num_pages, dst_loff);
3355
3356 out:
3357         if (ret)
3358                 btrfs_cmp_data_free(cmp);
3359         return ret;
3360 }
3361
3362 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3363 {
3364         int ret = 0;
3365         int i;
3366         struct page *src_page, *dst_page;
3367         unsigned int cmp_len = PAGE_SIZE;
3368         void *addr, *dst_addr;
3369
3370         i = 0;
3371         while (len) {
3372                 if (len < PAGE_SIZE)
3373                         cmp_len = len;
3374
3375                 BUG_ON(i >= cmp->num_pages);
3376
3377                 src_page = cmp->src_pages[i];
3378                 dst_page = cmp->dst_pages[i];
3379                 ASSERT(PageLocked(src_page));
3380                 ASSERT(PageLocked(dst_page));
3381
3382                 addr = kmap_atomic(src_page);
3383                 dst_addr = kmap_atomic(dst_page);
3384
3385                 flush_dcache_page(src_page);
3386                 flush_dcache_page(dst_page);
3387
3388                 if (memcmp(addr, dst_addr, cmp_len))
3389                         ret = -EBADE;
3390
3391                 kunmap_atomic(addr);
3392                 kunmap_atomic(dst_addr);
3393
3394                 if (ret)
3395                         break;
3396
3397                 len -= cmp_len;
3398                 i++;
3399         }
3400
3401         return ret;
3402 }
3403
3404 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3405                                      u64 olen)
3406 {
3407         u64 len = *plen;
3408         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3409
3410         if (off + olen > inode->i_size || off + olen < off)
3411                 return -EINVAL;
3412
3413         /* if we extend to eof, continue to block boundary */
3414         if (off + len == inode->i_size)
3415                 *plen = len = ALIGN(inode->i_size, bs) - off;
3416
3417         /* Check that we are block aligned - btrfs_clone() requires this */
3418         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3419                 return -EINVAL;
3420
3421         return 0;
3422 }
3423
3424 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
3425                                    struct inode *dst, u64 dst_loff,
3426                                    struct cmp_pages *cmp)
3427 {
3428         int ret;
3429         u64 len = olen;
3430         bool same_inode = (src == dst);
3431         u64 same_lock_start = 0;
3432         u64 same_lock_len = 0;
3433
3434         ret = extent_same_check_offsets(src, loff, &len, olen);
3435         if (ret)
3436                 return ret;
3437
3438         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3439         if (ret)
3440                 return ret;
3441
3442         if (same_inode) {
3443                 /*
3444                  * Single inode case wants the same checks, except we
3445                  * don't want our length pushed out past i_size as
3446                  * comparing that data range makes no sense.
3447                  *
3448                  * extent_same_check_offsets() will do this for an
3449                  * unaligned length at i_size, so catch it here and
3450                  * reject the request.
3451                  *
3452                  * This effectively means we require aligned extents
3453                  * for the single-inode case, whereas the other cases
3454                  * allow an unaligned length so long as it ends at
3455                  * i_size.
3456                  */
3457                 if (len != olen)
3458                         return -EINVAL;
3459
3460                 /* Check for overlapping ranges */
3461                 if (dst_loff + len > loff && dst_loff < loff + len)
3462                         return -EINVAL;
3463
3464                 same_lock_start = min_t(u64, loff, dst_loff);
3465                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3466         }
3467
3468 again:
3469         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, cmp);
3470         if (ret)
3471                 return ret;
3472
3473         if (same_inode)
3474                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3475                                         false);
3476         else
3477                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3478                                                false);
3479         /*
3480          * If one of the inodes has dirty pages in the respective range or
3481          * ordered extents, we need to flush dellaloc and wait for all ordered
3482          * extents in the range. We must unlock the pages and the ranges in the
3483          * io trees to avoid deadlocks when flushing delalloc (requires locking
3484          * pages) and when waiting for ordered extents to complete (they require
3485          * range locking).
3486          */
3487         if (ret == -EAGAIN) {
3488                 /*
3489                  * Ranges in the io trees already unlocked. Now unlock all
3490                  * pages before waiting for all IO to complete.
3491                  */
3492                 btrfs_cmp_data_free(cmp);
3493                 if (same_inode) {
3494                         btrfs_wait_ordered_range(src, same_lock_start,
3495                                                  same_lock_len);
3496                 } else {
3497                         btrfs_wait_ordered_range(src, loff, len);
3498                         btrfs_wait_ordered_range(dst, dst_loff, len);
3499                 }
3500                 goto again;
3501         }
3502         ASSERT(ret == 0);
3503         if (WARN_ON(ret)) {
3504                 /* ranges in the io trees already unlocked */
3505                 btrfs_cmp_data_free(cmp);
3506                 return ret;
3507         }
3508
3509         /* pass original length for comparison so we stay within i_size */
3510         ret = btrfs_cmp_data(olen, cmp);
3511         if (ret == 0)
3512                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3513
3514         if (same_inode)
3515                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3516                               same_lock_start + same_lock_len - 1);
3517         else
3518                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3519
3520         btrfs_cmp_data_free(cmp);
3521
3522         return ret;
3523 }
3524
3525 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3526
3527 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3528                              struct inode *dst, u64 dst_loff)
3529 {
3530         int ret;
3531         struct cmp_pages cmp;
3532         int num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
3533         bool same_inode = (src == dst);
3534         u64 i, tail_len, chunk_count;
3535
3536         if (olen == 0)
3537                 return 0;
3538
3539         if (same_inode)
3540                 inode_lock(src);
3541         else
3542                 btrfs_double_inode_lock(src, dst);
3543
3544         /* don't make the dst file partly checksummed */
3545         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3546             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3547                 ret = -EINVAL;
3548                 goto out_unlock;
3549         }
3550
3551         tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3552         chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3553         if (chunk_count == 0)
3554                 num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
3555
3556         /*
3557          * If deduping ranges in the same inode, locking rules make it
3558          * mandatory to always lock pages in ascending order to avoid deadlocks
3559          * with concurrent tasks (such as starting writeback/delalloc).
3560          */
3561         if (same_inode && dst_loff < loff)
3562                 swap(loff, dst_loff);
3563
3564         /*
3565          * We must gather up all the pages before we initiate our extent
3566          * locking. We use an array for the page pointers. Size of the array is
3567          * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
3568          */
3569         cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3570                                        GFP_KERNEL | __GFP_ZERO);
3571         cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3572                                        GFP_KERNEL | __GFP_ZERO);
3573         if (!cmp.src_pages || !cmp.dst_pages) {
3574                 ret = -ENOMEM;
3575                 goto out_free;
3576         }
3577
3578         for (i = 0; i < chunk_count; i++) {
3579                 ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3580                                               dst, dst_loff, &cmp);
3581                 if (ret)
3582                         goto out_free;
3583
3584                 loff += BTRFS_MAX_DEDUPE_LEN;
3585                 dst_loff += BTRFS_MAX_DEDUPE_LEN;
3586         }
3587
3588         if (tail_len > 0)
3589                 ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3590                                               dst_loff, &cmp);
3591
3592 out_free:
3593         kvfree(cmp.src_pages);
3594         kvfree(cmp.dst_pages);
3595
3596 out_unlock:
3597         if (same_inode)
3598                 inode_unlock(src);
3599         else
3600                 btrfs_double_inode_unlock(src, dst);
3601
3602         return ret;
3603 }
3604
3605 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3606                                 struct file *dst_file, u64 dst_loff)
3607 {
3608         struct inode *src = file_inode(src_file);
3609         struct inode *dst = file_inode(dst_file);
3610         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3611         ssize_t res;
3612
3613         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3614                 /*
3615                  * Btrfs does not support blocksize < page_size. As a
3616                  * result, btrfs_cmp_data() won't correctly handle
3617                  * this situation without an update.
3618                  */
3619                 return -EINVAL;
3620         }
3621
3622         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3623         if (res)
3624                 return res;
3625         return olen;
3626 }
3627
3628 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3629                                      struct inode *inode,
3630                                      u64 endoff,
3631                                      const u64 destoff,
3632                                      const u64 olen,
3633                                      int no_time_update)
3634 {
3635         struct btrfs_root *root = BTRFS_I(inode)->root;
3636         int ret;
3637
3638         inode_inc_iversion(inode);
3639         if (!no_time_update)
3640                 inode->i_mtime = inode->i_ctime = current_time(inode);
3641         /*
3642          * We round up to the block size at eof when determining which
3643          * extents to clone above, but shouldn't round up the file size.
3644          */
3645         if (endoff > destoff + olen)
3646                 endoff = destoff + olen;
3647         if (endoff > inode->i_size)
3648                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3649
3650         ret = btrfs_update_inode(trans, root, inode);
3651         if (ret) {
3652                 btrfs_abort_transaction(trans, ret);
3653                 btrfs_end_transaction(trans);
3654                 goto out;
3655         }
3656         ret = btrfs_end_transaction(trans);
3657 out:
3658         return ret;
3659 }
3660
3661 static void clone_update_extent_map(struct btrfs_inode *inode,
3662                                     const struct btrfs_trans_handle *trans,
3663                                     const struct btrfs_path *path,
3664                                     const u64 hole_offset,
3665                                     const u64 hole_len)
3666 {
3667         struct extent_map_tree *em_tree = &inode->extent_tree;
3668         struct extent_map *em;
3669         int ret;
3670
3671         em = alloc_extent_map();
3672         if (!em) {
3673                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3674                 return;
3675         }
3676
3677         if (path) {
3678                 struct btrfs_file_extent_item *fi;
3679
3680                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3681                                     struct btrfs_file_extent_item);
3682                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3683                 em->generation = -1;
3684                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3685                     BTRFS_FILE_EXTENT_INLINE)
3686                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3687                                         &inode->runtime_flags);
3688         } else {
3689                 em->start = hole_offset;
3690                 em->len = hole_len;
3691                 em->ram_bytes = em->len;
3692                 em->orig_start = hole_offset;
3693                 em->block_start = EXTENT_MAP_HOLE;
3694                 em->block_len = 0;
3695                 em->orig_block_len = 0;
3696                 em->compress_type = BTRFS_COMPRESS_NONE;
3697                 em->generation = trans->transid;
3698         }
3699
3700         while (1) {
3701                 write_lock(&em_tree->lock);
3702                 ret = add_extent_mapping(em_tree, em, 1);
3703                 write_unlock(&em_tree->lock);
3704                 if (ret != -EEXIST) {
3705                         free_extent_map(em);
3706                         break;
3707                 }
3708                 btrfs_drop_extent_cache(inode, em->start,
3709                                         em->start + em->len - 1, 0);
3710         }
3711
3712         if (ret)
3713                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3714 }
3715
3716 /*
3717  * Make sure we do not end up inserting an inline extent into a file that has
3718  * already other (non-inline) extents. If a file has an inline extent it can
3719  * not have any other extents and the (single) inline extent must start at the
3720  * file offset 0. Failing to respect these rules will lead to file corruption,
3721  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3722  *
3723  * We can have extents that have been already written to disk or we can have
3724  * dirty ranges still in delalloc, in which case the extent maps and items are
3725  * created only when we run delalloc, and the delalloc ranges might fall outside
3726  * the range we are currently locking in the inode's io tree. So we check the
3727  * inode's i_size because of that (i_size updates are done while holding the
3728  * i_mutex, which we are holding here).
3729  * We also check to see if the inode has a size not greater than "datal" but has
3730  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3731  * protected against such concurrent fallocate calls by the i_mutex).
3732  *
3733  * If the file has no extents but a size greater than datal, do not allow the
3734  * copy because we would need turn the inline extent into a non-inline one (even
3735  * with NO_HOLES enabled). If we find our destination inode only has one inline
3736  * extent, just overwrite it with the source inline extent if its size is less
3737  * than the source extent's size, or we could copy the source inline extent's
3738  * data into the destination inode's inline extent if the later is greater then
3739  * the former.
3740  */
3741 static int clone_copy_inline_extent(struct inode *dst,
3742                                     struct btrfs_trans_handle *trans,
3743                                     struct btrfs_path *path,
3744                                     struct btrfs_key *new_key,
3745                                     const u64 drop_start,
3746                                     const u64 datal,
3747                                     const u64 skip,
3748                                     const u64 size,
3749                                     char *inline_data)
3750 {
3751         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3752         struct btrfs_root *root = BTRFS_I(dst)->root;
3753         const u64 aligned_end = ALIGN(new_key->offset + datal,
3754                                       fs_info->sectorsize);
3755         int ret;
3756         struct btrfs_key key;
3757
3758         if (new_key->offset > 0)
3759                 return -EOPNOTSUPP;
3760
3761         key.objectid = btrfs_ino(BTRFS_I(dst));
3762         key.type = BTRFS_EXTENT_DATA_KEY;
3763         key.offset = 0;
3764         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3765         if (ret < 0) {
3766                 return ret;
3767         } else if (ret > 0) {
3768                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3769                         ret = btrfs_next_leaf(root, path);
3770                         if (ret < 0)
3771                                 return ret;
3772                         else if (ret > 0)
3773                                 goto copy_inline_extent;
3774                 }
3775                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3776                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3777                     key.type == BTRFS_EXTENT_DATA_KEY) {
3778                         ASSERT(key.offset > 0);
3779                         return -EOPNOTSUPP;
3780                 }
3781         } else if (i_size_read(dst) <= datal) {
3782                 struct btrfs_file_extent_item *ei;
3783                 u64 ext_len;
3784
3785                 /*
3786                  * If the file size is <= datal, make sure there are no other
3787                  * extents following (can happen do to an fallocate call with
3788                  * the flag FALLOC_FL_KEEP_SIZE).
3789                  */
3790                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3791                                     struct btrfs_file_extent_item);
3792                 /*
3793                  * If it's an inline extent, it can not have other extents
3794                  * following it.
3795                  */
3796                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3797                     BTRFS_FILE_EXTENT_INLINE)
3798                         goto copy_inline_extent;
3799
3800                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3801                 if (ext_len > aligned_end)
3802                         return -EOPNOTSUPP;
3803
3804                 ret = btrfs_next_item(root, path);
3805                 if (ret < 0) {
3806                         return ret;
3807                 } else if (ret == 0) {
3808                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3809                                               path->slots[0]);
3810                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3811                             key.type == BTRFS_EXTENT_DATA_KEY)
3812                                 return -EOPNOTSUPP;
3813                 }
3814         }
3815
3816 copy_inline_extent:
3817         /*
3818          * We have no extent items, or we have an extent at offset 0 which may
3819          * or may not be inlined. All these cases are dealt the same way.
3820          */
3821         if (i_size_read(dst) > datal) {
3822                 /*
3823                  * If the destination inode has an inline extent...
3824                  * This would require copying the data from the source inline
3825                  * extent into the beginning of the destination's inline extent.
3826                  * But this is really complex, both extents can be compressed
3827                  * or just one of them, which would require decompressing and
3828                  * re-compressing data (which could increase the new compressed
3829                  * size, not allowing the compressed data to fit anymore in an
3830                  * inline extent).
3831                  * So just don't support this case for now (it should be rare,
3832                  * we are not really saving space when cloning inline extents).
3833                  */
3834                 return -EOPNOTSUPP;
3835         }
3836
3837         btrfs_release_path(path);
3838         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3839         if (ret)
3840                 return ret;
3841         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3842         if (ret)
3843                 return ret;
3844
3845         if (skip) {
3846                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3847
3848                 memmove(inline_data + start, inline_data + start + skip, datal);
3849         }
3850
3851         write_extent_buffer(path->nodes[0], inline_data,
3852                             btrfs_item_ptr_offset(path->nodes[0],
3853                                                   path->slots[0]),
3854                             size);
3855         inode_add_bytes(dst, datal);
3856
3857         return 0;
3858 }
3859
3860 /**
3861  * btrfs_clone() - clone a range from inode file to another
3862  *
3863  * @src: Inode to clone from
3864  * @inode: Inode to clone to
3865  * @off: Offset within source to start clone from
3866  * @olen: Original length, passed by user, of range to clone
3867  * @olen_aligned: Block-aligned value of olen
3868  * @destoff: Offset within @inode to start clone
3869  * @no_time_update: Whether to update mtime/ctime on the target inode
3870  */
3871 static int btrfs_clone(struct inode *src, struct inode *inode,
3872                        const u64 off, const u64 olen, const u64 olen_aligned,
3873                        const u64 destoff, int no_time_update)
3874 {
3875         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3876         struct btrfs_root *root = BTRFS_I(inode)->root;
3877         struct btrfs_path *path = NULL;
3878         struct extent_buffer *leaf;
3879         struct btrfs_trans_handle *trans;
3880         char *buf = NULL;
3881         struct btrfs_key key;
3882         u32 nritems;
3883         int slot;
3884         int ret;
3885         const u64 len = olen_aligned;
3886         u64 last_dest_end = destoff;
3887
3888         ret = -ENOMEM;
3889         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3890         if (!buf)
3891                 return ret;
3892
3893         path = btrfs_alloc_path();
3894         if (!path) {
3895                 kvfree(buf);
3896                 return ret;
3897         }
3898
3899         path->reada = READA_FORWARD;
3900         /* clone data */
3901         key.objectid = btrfs_ino(BTRFS_I(src));
3902         key.type = BTRFS_EXTENT_DATA_KEY;
3903         key.offset = off;
3904
3905         while (1) {
3906                 u64 next_key_min_offset = key.offset + 1;
3907
3908                 /*
3909                  * note the key will change type as we walk through the
3910                  * tree.
3911                  */
3912                 path->leave_spinning = 1;
3913                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3914                                 0, 0);
3915                 if (ret < 0)
3916                         goto out;
3917                 /*
3918                  * First search, if no extent item that starts at offset off was
3919                  * found but the previous item is an extent item, it's possible
3920                  * it might overlap our target range, therefore process it.
3921                  */
3922                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3923                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3924                                               path->slots[0] - 1);
3925                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3926                                 path->slots[0]--;
3927                 }
3928
3929                 nritems = btrfs_header_nritems(path->nodes[0]);
3930 process_slot:
3931                 if (path->slots[0] >= nritems) {
3932                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3933                         if (ret < 0)
3934                                 goto out;
3935                         if (ret > 0)
3936                                 break;
3937                         nritems = btrfs_header_nritems(path->nodes[0]);
3938                 }
3939                 leaf = path->nodes[0];
3940                 slot = path->slots[0];
3941
3942                 btrfs_item_key_to_cpu(leaf, &key, slot);
3943                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3944                     key.objectid != btrfs_ino(BTRFS_I(src)))
3945                         break;
3946
3947                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3948                         struct btrfs_file_extent_item *extent;
3949                         int type;
3950                         u32 size;
3951                         struct btrfs_key new_key;
3952                         u64 disko = 0, diskl = 0;
3953                         u64 datao = 0, datal = 0;
3954                         u8 comp;
3955                         u64 drop_start;
3956
3957                         extent = btrfs_item_ptr(leaf, slot,
3958                                                 struct btrfs_file_extent_item);
3959                         comp = btrfs_file_extent_compression(leaf, extent);
3960                         type = btrfs_file_extent_type(leaf, extent);
3961                         if (type == BTRFS_FILE_EXTENT_REG ||
3962                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3963                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3964                                                                       extent);
3965                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3966                                                                  extent);
3967                                 datao = btrfs_file_extent_offset(leaf, extent);
3968                                 datal = btrfs_file_extent_num_bytes(leaf,
3969                                                                     extent);
3970                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3971                                 /* take upper bound, may be compressed */
3972                                 datal = btrfs_file_extent_ram_bytes(leaf,
3973                                                                     extent);
3974                         }
3975
3976                         /*
3977                          * The first search might have left us at an extent
3978                          * item that ends before our target range's start, can
3979                          * happen if we have holes and NO_HOLES feature enabled.
3980                          */
3981                         if (key.offset + datal <= off) {
3982                                 path->slots[0]++;
3983                                 goto process_slot;
3984                         } else if (key.offset >= off + len) {
3985                                 break;
3986                         }
3987                         next_key_min_offset = key.offset + datal;
3988                         size = btrfs_item_size_nr(leaf, slot);
3989                         read_extent_buffer(leaf, buf,
3990                                            btrfs_item_ptr_offset(leaf, slot),
3991                                            size);
3992
3993                         btrfs_release_path(path);
3994                         path->leave_spinning = 0;
3995
3996                         memcpy(&new_key, &key, sizeof(new_key));
3997                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
3998                         if (off <= key.offset)
3999                                 new_key.offset = key.offset + destoff - off;
4000                         else
4001                                 new_key.offset = destoff;
4002
4003                         /*
4004                          * Deal with a hole that doesn't have an extent item
4005                          * that represents it (NO_HOLES feature enabled).
4006                          * This hole is either in the middle of the cloning
4007                          * range or at the beginning (fully overlaps it or
4008                          * partially overlaps it).
4009                          */
4010                         if (new_key.offset != last_dest_end)
4011                                 drop_start = last_dest_end;
4012                         else
4013                                 drop_start = new_key.offset;
4014
4015                         /*
4016                          * 1 - adjusting old extent (we may have to split it)
4017                          * 1 - add new extent
4018                          * 1 - inode update
4019                          */
4020                         trans = btrfs_start_transaction(root, 3);
4021                         if (IS_ERR(trans)) {
4022                                 ret = PTR_ERR(trans);
4023                                 goto out;
4024                         }
4025
4026                         if (type == BTRFS_FILE_EXTENT_REG ||
4027                             type == BTRFS_FILE_EXTENT_PREALLOC) {
4028                                 /*
4029                                  *    a  | --- range to clone ---|  b
4030                                  * | ------------- extent ------------- |
4031                                  */
4032
4033                                 /* subtract range b */
4034                                 if (key.offset + datal > off + len)
4035                                         datal = off + len - key.offset;
4036
4037                                 /* subtract range a */
4038                                 if (off > key.offset) {
4039                                         datao += off - key.offset;
4040                                         datal -= off - key.offset;
4041                                 }
4042
4043                                 ret = btrfs_drop_extents(trans, root, inode,
4044                                                          drop_start,
4045                                                          new_key.offset + datal,
4046                                                          1);
4047                                 if (ret) {
4048                                         if (ret != -EOPNOTSUPP)
4049                                                 btrfs_abort_transaction(trans,
4050                                                                         ret);
4051                                         btrfs_end_transaction(trans);
4052                                         goto out;
4053                                 }
4054
4055                                 ret = btrfs_insert_empty_item(trans, root, path,
4056                                                               &new_key, size);
4057                                 if (ret) {
4058                                         btrfs_abort_transaction(trans, ret);
4059                                         btrfs_end_transaction(trans);
4060                                         goto out;
4061                                 }
4062
4063                                 leaf = path->nodes[0];
4064                                 slot = path->slots[0];
4065                                 write_extent_buffer(leaf, buf,
4066                                             btrfs_item_ptr_offset(leaf, slot),
4067                                             size);
4068
4069                                 extent = btrfs_item_ptr(leaf, slot,
4070                                                 struct btrfs_file_extent_item);
4071
4072                                 /* disko == 0 means it's a hole */
4073                                 if (!disko)
4074                                         datao = 0;
4075
4076                                 btrfs_set_file_extent_offset(leaf, extent,
4077                                                              datao);
4078                                 btrfs_set_file_extent_num_bytes(leaf, extent,
4079                                                                 datal);
4080
4081                                 if (disko) {
4082                                         inode_add_bytes(inode, datal);
4083                                         ret = btrfs_inc_extent_ref(trans,
4084                                                         root,
4085                                                         disko, diskl, 0,
4086                                                         root->root_key.objectid,
4087                                                         btrfs_ino(BTRFS_I(inode)),
4088                                                         new_key.offset - datao);
4089                                         if (ret) {
4090                                                 btrfs_abort_transaction(trans,
4091                                                                         ret);
4092                                                 btrfs_end_transaction(trans);
4093                                                 goto out;
4094
4095                                         }
4096                                 }
4097                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
4098                                 u64 skip = 0;
4099                                 u64 trim = 0;
4100
4101                                 if (off > key.offset) {
4102                                         skip = off - key.offset;
4103                                         new_key.offset += skip;
4104                                 }
4105
4106                                 if (key.offset + datal > off + len)
4107                                         trim = key.offset + datal - (off + len);
4108
4109                                 if (comp && (skip || trim)) {
4110                                         ret = -EINVAL;
4111                                         btrfs_end_transaction(trans);
4112                                         goto out;
4113                                 }
4114                                 size -= skip + trim;
4115                                 datal -= skip + trim;
4116
4117                                 ret = clone_copy_inline_extent(inode,
4118                                                                trans, path,
4119                                                                &new_key,
4120                                                                drop_start,
4121                                                                datal,
4122                                                                skip, size, buf);
4123                                 if (ret) {
4124                                         if (ret != -EOPNOTSUPP)
4125                                                 btrfs_abort_transaction(trans,
4126                                                                         ret);
4127                                         btrfs_end_transaction(trans);
4128                                         goto out;
4129                                 }
4130                                 leaf = path->nodes[0];
4131                                 slot = path->slots[0];
4132                         }
4133
4134                         /* If we have an implicit hole (NO_HOLES feature). */
4135                         if (drop_start < new_key.offset)
4136                                 clone_update_extent_map(BTRFS_I(inode), trans,
4137                                                 NULL, drop_start,
4138                                                 new_key.offset - drop_start);
4139
4140                         clone_update_extent_map(BTRFS_I(inode), trans,
4141                                         path, 0, 0);
4142
4143                         btrfs_mark_buffer_dirty(leaf);
4144                         btrfs_release_path(path);
4145
4146                         last_dest_end = ALIGN(new_key.offset + datal,
4147                                               fs_info->sectorsize);
4148                         ret = clone_finish_inode_update(trans, inode,
4149                                                         last_dest_end,
4150                                                         destoff, olen,
4151                                                         no_time_update);
4152                         if (ret)
4153                                 goto out;
4154                         if (new_key.offset + datal >= destoff + len)
4155                                 break;
4156                 }
4157                 btrfs_release_path(path);
4158                 key.offset = next_key_min_offset;
4159
4160                 if (fatal_signal_pending(current)) {
4161                         ret = -EINTR;
4162                         goto out;
4163                 }
4164         }
4165         ret = 0;
4166
4167         if (last_dest_end < destoff + len) {
4168                 /*
4169                  * We have an implicit hole (NO_HOLES feature is enabled) that
4170                  * fully or partially overlaps our cloning range at its end.
4171                  */
4172                 btrfs_release_path(path);
4173
4174                 /*
4175                  * 1 - remove extent(s)
4176                  * 1 - inode update
4177                  */
4178                 trans = btrfs_start_transaction(root, 2);
4179                 if (IS_ERR(trans)) {
4180                         ret = PTR_ERR(trans);
4181                         goto out;
4182                 }
4183                 ret = btrfs_drop_extents(trans, root, inode,
4184                                          last_dest_end, destoff + len, 1);
4185                 if (ret) {
4186                         if (ret != -EOPNOTSUPP)
4187                                 btrfs_abort_transaction(trans, ret);
4188                         btrfs_end_transaction(trans);
4189                         goto out;
4190                 }
4191                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
4192                                 last_dest_end,
4193                                 destoff + len - last_dest_end);
4194                 ret = clone_finish_inode_update(trans, inode, destoff + len,
4195                                                 destoff, olen, no_time_update);
4196         }
4197
4198 out:
4199         btrfs_free_path(path);
4200         kvfree(buf);
4201         return ret;
4202 }
4203
4204 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
4205                                         u64 off, u64 olen, u64 destoff)
4206 {
4207         struct inode *inode = file_inode(file);
4208         struct inode *src = file_inode(file_src);
4209         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4210         struct btrfs_root *root = BTRFS_I(inode)->root;
4211         int ret;
4212         u64 len = olen;
4213         u64 bs = fs_info->sb->s_blocksize;
4214         int same_inode = src == inode;
4215
4216         /*
4217          * TODO:
4218          * - split compressed inline extents.  annoying: we need to
4219          *   decompress into destination's address_space (the file offset
4220          *   may change, so source mapping won't do), then recompress (or
4221          *   otherwise reinsert) a subrange.
4222          *
4223          * - split destination inode's inline extents.  The inline extents can
4224          *   be either compressed or non-compressed.
4225          */
4226
4227         if (btrfs_root_readonly(root))
4228                 return -EROFS;
4229
4230         if (file_src->f_path.mnt != file->f_path.mnt ||
4231             src->i_sb != inode->i_sb)
4232                 return -EXDEV;
4233
4234         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
4235                 return -EISDIR;
4236
4237         if (!same_inode) {
4238                 btrfs_double_inode_lock(src, inode);
4239         } else {
4240                 inode_lock(src);
4241         }
4242
4243         /* don't make the dst file partly checksummed */
4244         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
4245             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
4246                 ret = -EINVAL;
4247                 goto out_unlock;
4248         }
4249
4250         /* determine range to clone */
4251         ret = -EINVAL;
4252         if (off + len > src->i_size || off + len < off)
4253                 goto out_unlock;
4254         if (len == 0)
4255                 olen = len = src->i_size - off;
4256         /* if we extend to eof, continue to block boundary */
4257         if (off + len == src->i_size)
4258                 len = ALIGN(src->i_size, bs) - off;
4259
4260         if (len == 0) {
4261                 ret = 0;
4262                 goto out_unlock;
4263         }
4264
4265         /* verify the end result is block aligned */
4266         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
4267             !IS_ALIGNED(destoff, bs))
4268                 goto out_unlock;
4269
4270         /* verify if ranges are overlapped within the same file */
4271         if (same_inode) {
4272                 if (destoff + len > off && destoff < off + len)
4273                         goto out_unlock;
4274         }
4275
4276         if (destoff > inode->i_size) {
4277                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
4278                 if (ret)
4279                         goto out_unlock;
4280         }
4281
4282         /*
4283          * Lock the target range too. Right after we replace the file extent
4284          * items in the fs tree (which now point to the cloned data), we might
4285          * have a worker replace them with extent items relative to a write
4286          * operation that was issued before this clone operation (i.e. confront
4287          * with inode.c:btrfs_finish_ordered_io).
4288          */
4289         if (same_inode) {
4290                 u64 lock_start = min_t(u64, off, destoff);
4291                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
4292
4293                 ret = lock_extent_range(src, lock_start, lock_len, true);
4294         } else {
4295                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
4296                                                true);
4297         }
4298         ASSERT(ret == 0);
4299         if (WARN_ON(ret)) {
4300                 /* ranges in the io trees already unlocked */
4301                 goto out_unlock;
4302         }
4303
4304         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
4305
4306         if (same_inode) {
4307                 u64 lock_start = min_t(u64, off, destoff);
4308                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
4309
4310                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
4311         } else {
4312                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
4313         }
4314         /*
4315          * Truncate page cache pages so that future reads will see the cloned
4316          * data immediately and not the previous data.
4317          */
4318         truncate_inode_pages_range(&inode->i_data,
4319                                 round_down(destoff, PAGE_SIZE),
4320                                 round_up(destoff + len, PAGE_SIZE) - 1);
4321 out_unlock:
4322         if (!same_inode)
4323                 btrfs_double_inode_unlock(src, inode);
4324         else
4325                 inode_unlock(src);
4326         return ret;
4327 }
4328
4329 int btrfs_clone_file_range(struct file *src_file, loff_t off,
4330                 struct file *dst_file, loff_t destoff, u64 len)
4331 {
4332         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
4333 }
4334
4335 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4336 {
4337         struct inode *inode = file_inode(file);
4338         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4339         struct btrfs_root *root = BTRFS_I(inode)->root;
4340         struct btrfs_root *new_root;
4341         struct btrfs_dir_item *di;
4342         struct btrfs_trans_handle *trans;
4343         struct btrfs_path *path;
4344         struct btrfs_key location;
4345         struct btrfs_disk_key disk_key;
4346         u64 objectid = 0;
4347         u64 dir_id;
4348         int ret;
4349
4350         if (!capable(CAP_SYS_ADMIN))
4351                 return -EPERM;
4352
4353         ret = mnt_want_write_file(file);
4354         if (ret)
4355                 return ret;
4356
4357         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4358                 ret = -EFAULT;
4359                 goto out;
4360         }
4361
4362         if (!objectid)
4363                 objectid = BTRFS_FS_TREE_OBJECTID;
4364
4365         location.objectid = objectid;
4366         location.type = BTRFS_ROOT_ITEM_KEY;
4367         location.offset = (u64)-1;
4368
4369         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4370         if (IS_ERR(new_root)) {
4371                 ret = PTR_ERR(new_root);
4372                 goto out;
4373         }
4374         if (!is_fstree(new_root->objectid)) {
4375                 ret = -ENOENT;
4376                 goto out;
4377         }
4378
4379         path = btrfs_alloc_path();
4380         if (!path) {
4381                 ret = -ENOMEM;
4382                 goto out;
4383         }
4384         path->leave_spinning = 1;
4385
4386         trans = btrfs_start_transaction(root, 1);
4387         if (IS_ERR(trans)) {
4388                 btrfs_free_path(path);
4389                 ret = PTR_ERR(trans);
4390                 goto out;
4391         }
4392
4393         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4394         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4395                                    dir_id, "default", 7, 1);
4396         if (IS_ERR_OR_NULL(di)) {
4397                 btrfs_free_path(path);
4398                 btrfs_end_transaction(trans);
4399                 btrfs_err(fs_info,
4400                           "Umm, you don't have the default diritem, this isn't going to work");
4401                 ret = -ENOENT;
4402                 goto out;
4403         }
4404
4405         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4406         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4407         btrfs_mark_buffer_dirty(path->nodes[0]);
4408         btrfs_free_path(path);
4409
4410         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4411         btrfs_end_transaction(trans);
4412 out:
4413         mnt_drop_write_file(file);
4414         return ret;
4415 }
4416
4417 static void get_block_group_info(struct list_head *groups_list,
4418                                  struct btrfs_ioctl_space_info *space)
4419 {
4420         struct btrfs_block_group_cache *block_group;
4421
4422         space->total_bytes = 0;
4423         space->used_bytes = 0;
4424         space->flags = 0;
4425         list_for_each_entry(block_group, groups_list, list) {
4426                 space->flags = block_group->flags;
4427                 space->total_bytes += block_group->key.offset;
4428                 space->used_bytes +=
4429                         btrfs_block_group_used(&block_group->item);
4430         }
4431 }
4432
4433 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4434                                    void __user *arg)
4435 {
4436         struct btrfs_ioctl_space_args space_args;
4437         struct btrfs_ioctl_space_info space;
4438         struct btrfs_ioctl_space_info *dest;
4439         struct btrfs_ioctl_space_info *dest_orig;
4440         struct btrfs_ioctl_space_info __user *user_dest;
4441         struct btrfs_space_info *info;
4442         static const u64 types[] = {
4443                 BTRFS_BLOCK_GROUP_DATA,
4444                 BTRFS_BLOCK_GROUP_SYSTEM,
4445                 BTRFS_BLOCK_GROUP_METADATA,
4446                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4447         };
4448         int num_types = 4;
4449         int alloc_size;
4450         int ret = 0;
4451         u64 slot_count = 0;
4452         int i, c;
4453
4454         if (copy_from_user(&space_args,
4455                            (struct btrfs_ioctl_space_args __user *)arg,
4456                            sizeof(space_args)))
4457                 return -EFAULT;
4458
4459         for (i = 0; i < num_types; i++) {
4460                 struct btrfs_space_info *tmp;
4461
4462                 info = NULL;
4463                 rcu_read_lock();
4464                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4465                                         list) {
4466                         if (tmp->flags == types[i]) {
4467                                 info = tmp;
4468                                 break;
4469                         }
4470                 }
4471                 rcu_read_unlock();
4472
4473                 if (!info)
4474                         continue;
4475
4476                 down_read(&info->groups_sem);
4477                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4478                         if (!list_empty(&info->block_groups[c]))
4479                                 slot_count++;
4480                 }
4481                 up_read(&info->groups_sem);
4482         }
4483
4484         /*
4485          * Global block reserve, exported as a space_info
4486          */
4487         slot_count++;
4488
4489         /* space_slots == 0 means they are asking for a count */
4490         if (space_args.space_slots == 0) {
4491                 space_args.total_spaces = slot_count;
4492                 goto out;
4493         }
4494
4495         slot_count = min_t(u64, space_args.space_slots, slot_count);
4496
4497         alloc_size = sizeof(*dest) * slot_count;
4498
4499         /* we generally have at most 6 or so space infos, one for each raid
4500          * level.  So, a whole page should be more than enough for everyone
4501          */
4502         if (alloc_size > PAGE_SIZE)
4503                 return -ENOMEM;
4504
4505         space_args.total_spaces = 0;
4506         dest = kmalloc(alloc_size, GFP_KERNEL);
4507         if (!dest)
4508                 return -ENOMEM;
4509         dest_orig = dest;
4510
4511         /* now we have a buffer to copy into */
4512         for (i = 0; i < num_types; i++) {
4513                 struct btrfs_space_info *tmp;
4514
4515                 if (!slot_count)
4516                         break;
4517
4518                 info = NULL;
4519                 rcu_read_lock();
4520                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4521                                         list) {
4522                         if (tmp->flags == types[i]) {
4523                                 info = tmp;
4524                                 break;
4525                         }
4526                 }
4527                 rcu_read_unlock();
4528
4529                 if (!info)
4530                         continue;
4531                 down_read(&info->groups_sem);
4532                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4533                         if (!list_empty(&info->block_groups[c])) {
4534                                 get_block_group_info(&info->block_groups[c],
4535                                                      &space);
4536                                 memcpy(dest, &space, sizeof(space));
4537                                 dest++;
4538                                 space_args.total_spaces++;
4539                                 slot_count--;
4540                         }
4541                         if (!slot_count)
4542                                 break;
4543                 }
4544                 up_read(&info->groups_sem);
4545         }
4546
4547         /*
4548          * Add global block reserve
4549          */
4550         if (slot_count) {
4551                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4552
4553                 spin_lock(&block_rsv->lock);
4554                 space.total_bytes = block_rsv->size;
4555                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4556                 spin_unlock(&block_rsv->lock);
4557                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4558                 memcpy(dest, &space, sizeof(space));
4559                 space_args.total_spaces++;
4560         }
4561
4562         user_dest = (struct btrfs_ioctl_space_info __user *)
4563                 (arg + sizeof(struct btrfs_ioctl_space_args));
4564
4565         if (copy_to_user(user_dest, dest_orig, alloc_size))
4566                 ret = -EFAULT;
4567
4568         kfree(dest_orig);
4569 out:
4570         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4571                 ret = -EFAULT;
4572
4573         return ret;
4574 }
4575
4576 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4577                                             void __user *argp)
4578 {
4579         struct btrfs_trans_handle *trans;
4580         u64 transid;
4581         int ret;
4582
4583         trans = btrfs_attach_transaction_barrier(root);
4584         if (IS_ERR(trans)) {
4585                 if (PTR_ERR(trans) != -ENOENT)
4586                         return PTR_ERR(trans);
4587
4588                 /* No running transaction, don't bother */
4589                 transid = root->fs_info->last_trans_committed;
4590                 goto out;
4591         }
4592         transid = trans->transid;
4593         ret = btrfs_commit_transaction_async(trans, 0);
4594         if (ret) {
4595                 btrfs_end_transaction(trans);
4596                 return ret;
4597         }
4598 out:
4599         if (argp)
4600                 if (copy_to_user(argp, &transid, sizeof(transid)))
4601                         return -EFAULT;
4602         return 0;
4603 }
4604
4605 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4606                                            void __user *argp)
4607 {
4608         u64 transid;
4609
4610         if (argp) {
4611                 if (copy_from_user(&transid, argp, sizeof(transid)))
4612                         return -EFAULT;
4613         } else {
4614                 transid = 0;  /* current trans */
4615         }
4616         return btrfs_wait_for_commit(fs_info, transid);
4617 }
4618
4619 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4620 {
4621         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4622         struct btrfs_ioctl_scrub_args *sa;
4623         int ret;
4624
4625         if (!capable(CAP_SYS_ADMIN))
4626                 return -EPERM;
4627
4628         sa = memdup_user(arg, sizeof(*sa));
4629         if (IS_ERR(sa))
4630                 return PTR_ERR(sa);
4631
4632         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4633                 ret = mnt_want_write_file(file);
4634                 if (ret)
4635                         goto out;
4636         }
4637
4638         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4639                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4640                               0);
4641
4642         if (copy_to_user(arg, sa, sizeof(*sa)))
4643                 ret = -EFAULT;
4644
4645         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4646                 mnt_drop_write_file(file);
4647 out:
4648         kfree(sa);
4649         return ret;
4650 }
4651
4652 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4653 {
4654         if (!capable(CAP_SYS_ADMIN))
4655                 return -EPERM;
4656
4657         return btrfs_scrub_cancel(fs_info);
4658 }
4659
4660 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4661                                        void __user *arg)
4662 {
4663         struct btrfs_ioctl_scrub_args *sa;
4664         int ret;
4665
4666         if (!capable(CAP_SYS_ADMIN))
4667                 return -EPERM;
4668
4669         sa = memdup_user(arg, sizeof(*sa));
4670         if (IS_ERR(sa))
4671                 return PTR_ERR(sa);
4672
4673         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4674
4675         if (copy_to_user(arg, sa, sizeof(*sa)))
4676                 ret = -EFAULT;
4677
4678         kfree(sa);
4679         return ret;
4680 }
4681
4682 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4683                                       void __user *arg)
4684 {
4685         struct btrfs_ioctl_get_dev_stats *sa;
4686         int ret;
4687
4688         sa = memdup_user(arg, sizeof(*sa));
4689         if (IS_ERR(sa))
4690                 return PTR_ERR(sa);
4691
4692         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4693                 kfree(sa);
4694                 return -EPERM;
4695         }
4696
4697         ret = btrfs_get_dev_stats(fs_info, sa);
4698
4699         if (copy_to_user(arg, sa, sizeof(*sa)))
4700                 ret = -EFAULT;
4701
4702         kfree(sa);
4703         return ret;
4704 }
4705
4706 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4707                                     void __user *arg)
4708 {
4709         struct btrfs_ioctl_dev_replace_args *p;
4710         int ret;
4711
4712         if (!capable(CAP_SYS_ADMIN))
4713                 return -EPERM;
4714
4715         p = memdup_user(arg, sizeof(*p));
4716         if (IS_ERR(p))
4717                 return PTR_ERR(p);
4718
4719         switch (p->cmd) {
4720         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4721                 if (sb_rdonly(fs_info->sb)) {
4722                         ret = -EROFS;
4723                         goto out;
4724                 }
4725                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4726                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4727                 } else {
4728                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4729                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4730                 }
4731                 break;
4732         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4733                 btrfs_dev_replace_status(fs_info, p);
4734                 ret = 0;
4735                 break;
4736         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4737                 p->result = btrfs_dev_replace_cancel(fs_info);
4738                 ret = 0;
4739                 break;
4740         default:
4741                 ret = -EINVAL;
4742                 break;
4743         }
4744
4745         if (copy_to_user(arg, p, sizeof(*p)))
4746                 ret = -EFAULT;
4747 out:
4748         kfree(p);
4749         return ret;
4750 }
4751
4752 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4753 {
4754         int ret = 0;
4755         int i;
4756         u64 rel_ptr;
4757         int size;
4758         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4759         struct inode_fs_paths *ipath = NULL;
4760         struct btrfs_path *path;
4761
4762         if (!capable(CAP_DAC_READ_SEARCH))
4763                 return -EPERM;
4764
4765         path = btrfs_alloc_path();
4766         if (!path) {
4767                 ret = -ENOMEM;
4768                 goto out;
4769         }
4770
4771         ipa = memdup_user(arg, sizeof(*ipa));
4772         if (IS_ERR(ipa)) {
4773                 ret = PTR_ERR(ipa);
4774                 ipa = NULL;
4775                 goto out;
4776         }
4777
4778         size = min_t(u32, ipa->size, 4096);
4779         ipath = init_ipath(size, root, path);
4780         if (IS_ERR(ipath)) {
4781                 ret = PTR_ERR(ipath);
4782                 ipath = NULL;
4783                 goto out;
4784         }
4785
4786         ret = paths_from_inode(ipa->inum, ipath);
4787         if (ret < 0)
4788                 goto out;
4789
4790         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4791                 rel_ptr = ipath->fspath->val[i] -
4792                           (u64)(unsigned long)ipath->fspath->val;
4793                 ipath->fspath->val[i] = rel_ptr;
4794         }
4795
4796         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4797                            ipath->fspath, size);
4798         if (ret) {
4799                 ret = -EFAULT;
4800                 goto out;
4801         }
4802
4803 out:
4804         btrfs_free_path(path);
4805         free_ipath(ipath);
4806         kfree(ipa);
4807
4808         return ret;
4809 }
4810
4811 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4812 {
4813         struct btrfs_data_container *inodes = ctx;
4814         const size_t c = 3 * sizeof(u64);
4815
4816         if (inodes->bytes_left >= c) {
4817                 inodes->bytes_left -= c;
4818                 inodes->val[inodes->elem_cnt] = inum;
4819                 inodes->val[inodes->elem_cnt + 1] = offset;
4820                 inodes->val[inodes->elem_cnt + 2] = root;
4821                 inodes->elem_cnt += 3;
4822         } else {
4823                 inodes->bytes_missing += c - inodes->bytes_left;
4824                 inodes->bytes_left = 0;
4825                 inodes->elem_missed += 3;
4826         }
4827
4828         return 0;
4829 }
4830
4831 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4832                                         void __user *arg, int version)
4833 {
4834         int ret = 0;
4835         int size;
4836         struct btrfs_ioctl_logical_ino_args *loi;
4837         struct btrfs_data_container *inodes = NULL;
4838         struct btrfs_path *path = NULL;
4839         bool ignore_offset;
4840
4841         if (!capable(CAP_SYS_ADMIN))
4842                 return -EPERM;
4843
4844         loi = memdup_user(arg, sizeof(*loi));
4845         if (IS_ERR(loi))
4846                 return PTR_ERR(loi);
4847
4848         if (version == 1) {
4849                 ignore_offset = false;
4850                 size = min_t(u32, loi->size, SZ_64K);
4851         } else {
4852                 /* All reserved bits must be 0 for now */
4853                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4854                         ret = -EINVAL;
4855                         goto out_loi;
4856                 }
4857                 /* Only accept flags we have defined so far */
4858                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4859                         ret = -EINVAL;
4860                         goto out_loi;
4861                 }
4862                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4863                 size = min_t(u32, loi->size, SZ_16M);
4864         }
4865
4866         path = btrfs_alloc_path();
4867         if (!path) {
4868                 ret = -ENOMEM;
4869                 goto out;
4870         }
4871
4872         inodes = init_data_container(size);
4873         if (IS_ERR(inodes)) {
4874                 ret = PTR_ERR(inodes);
4875                 inodes = NULL;
4876                 goto out;
4877         }
4878
4879         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4880                                           build_ino_list, inodes, ignore_offset);
4881         if (ret == -EINVAL)
4882                 ret = -ENOENT;
4883         if (ret < 0)
4884                 goto out;
4885
4886         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4887                            size);
4888         if (ret)
4889                 ret = -EFAULT;
4890
4891 out:
4892         btrfs_free_path(path);
4893         kvfree(inodes);
4894 out_loi:
4895         kfree(loi);
4896
4897         return ret;
4898 }
4899
4900 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4901                                struct btrfs_ioctl_balance_args *bargs)
4902 {
4903         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4904
4905         bargs->flags = bctl->flags;
4906
4907         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4908                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4909         if (atomic_read(&fs_info->balance_pause_req))
4910                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4911         if (atomic_read(&fs_info->balance_cancel_req))
4912                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4913
4914         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4915         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4916         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4917
4918         spin_lock(&fs_info->balance_lock);
4919         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4920         spin_unlock(&fs_info->balance_lock);
4921 }
4922
4923 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4924 {
4925         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4926         struct btrfs_fs_info *fs_info = root->fs_info;
4927         struct btrfs_ioctl_balance_args *bargs;
4928         struct btrfs_balance_control *bctl;
4929         bool need_unlock; /* for mut. excl. ops lock */
4930         int ret;
4931
4932         if (!capable(CAP_SYS_ADMIN))
4933                 return -EPERM;
4934
4935         ret = mnt_want_write_file(file);
4936         if (ret)
4937                 return ret;
4938
4939 again:
4940         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4941                 mutex_lock(&fs_info->balance_mutex);
4942                 need_unlock = true;
4943                 goto locked;
4944         }
4945
4946         /*
4947          * mut. excl. ops lock is locked.  Three possibilities:
4948          *   (1) some other op is running
4949          *   (2) balance is running
4950          *   (3) balance is paused -- special case (think resume)
4951          */
4952         mutex_lock(&fs_info->balance_mutex);
4953         if (fs_info->balance_ctl) {
4954                 /* this is either (2) or (3) */
4955                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4956                         mutex_unlock(&fs_info->balance_mutex);
4957                         /*
4958                          * Lock released to allow other waiters to continue,
4959                          * we'll reexamine the status again.
4960                          */
4961                         mutex_lock(&fs_info->balance_mutex);
4962
4963                         if (fs_info->balance_ctl &&
4964                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4965                                 /* this is (3) */
4966                                 need_unlock = false;
4967                                 goto locked;
4968                         }
4969
4970                         mutex_unlock(&fs_info->balance_mutex);
4971                         goto again;
4972                 } else {
4973                         /* this is (2) */
4974                         mutex_unlock(&fs_info->balance_mutex);
4975                         ret = -EINPROGRESS;
4976                         goto out;
4977                 }
4978         } else {
4979                 /* this is (1) */
4980                 mutex_unlock(&fs_info->balance_mutex);
4981                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4982                 goto out;
4983         }
4984
4985 locked:
4986         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4987
4988         if (arg) {
4989                 bargs = memdup_user(arg, sizeof(*bargs));
4990                 if (IS_ERR(bargs)) {
4991                         ret = PTR_ERR(bargs);
4992                         goto out_unlock;
4993                 }
4994
4995                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4996                         if (!fs_info->balance_ctl) {
4997                                 ret = -ENOTCONN;
4998                                 goto out_bargs;
4999                         }
5000
5001                         bctl = fs_info->balance_ctl;
5002                         spin_lock(&fs_info->balance_lock);
5003                         bctl->flags |= BTRFS_BALANCE_RESUME;
5004                         spin_unlock(&fs_info->balance_lock);
5005
5006                         goto do_balance;
5007                 }
5008         } else {
5009                 bargs = NULL;
5010         }
5011
5012         if (fs_info->balance_ctl) {
5013                 ret = -EINPROGRESS;
5014                 goto out_bargs;
5015         }
5016
5017         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
5018         if (!bctl) {
5019                 ret = -ENOMEM;
5020                 goto out_bargs;
5021         }
5022
5023         if (arg) {
5024                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
5025                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
5026                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
5027
5028                 bctl->flags = bargs->flags;
5029         } else {
5030                 /* balance everything - no filters */
5031                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
5032         }
5033
5034         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
5035                 ret = -EINVAL;
5036                 goto out_bctl;
5037         }
5038
5039 do_balance:
5040         /*
5041          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
5042          * btrfs_balance.  bctl is freed in reset_balance_state, or, if
5043          * restriper was paused all the way until unmount, in free_fs_info.
5044          * The flag should be cleared after reset_balance_state.
5045          */
5046         need_unlock = false;
5047
5048         ret = btrfs_balance(fs_info, bctl, bargs);
5049         bctl = NULL;
5050
5051         if (arg) {
5052                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
5053                         ret = -EFAULT;
5054         }
5055
5056 out_bctl:
5057         kfree(bctl);
5058 out_bargs:
5059         kfree(bargs);
5060 out_unlock:
5061         mutex_unlock(&fs_info->balance_mutex);
5062         if (need_unlock)
5063                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
5064 out:
5065         mnt_drop_write_file(file);
5066         return ret;
5067 }
5068
5069 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
5070 {
5071         if (!capable(CAP_SYS_ADMIN))
5072                 return -EPERM;
5073
5074         switch (cmd) {
5075         case BTRFS_BALANCE_CTL_PAUSE:
5076                 return btrfs_pause_balance(fs_info);
5077         case BTRFS_BALANCE_CTL_CANCEL:
5078                 return btrfs_cancel_balance(fs_info);
5079         }
5080
5081         return -EINVAL;
5082 }
5083
5084 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
5085                                          void __user *arg)
5086 {
5087         struct btrfs_ioctl_balance_args *bargs;
5088         int ret = 0;
5089
5090         if (!capable(CAP_SYS_ADMIN))
5091                 return -EPERM;
5092
5093         mutex_lock(&fs_info->balance_mutex);
5094         if (!fs_info->balance_ctl) {
5095                 ret = -ENOTCONN;
5096                 goto out;
5097         }
5098
5099         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
5100         if (!bargs) {
5101                 ret = -ENOMEM;
5102                 goto out;
5103         }
5104
5105         btrfs_update_ioctl_balance_args(fs_info, bargs);
5106
5107         if (copy_to_user(arg, bargs, sizeof(*bargs)))
5108                 ret = -EFAULT;
5109
5110         kfree(bargs);
5111 out:
5112         mutex_unlock(&fs_info->balance_mutex);
5113         return ret;
5114 }
5115
5116 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
5117 {
5118         struct inode *inode = file_inode(file);
5119         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5120         struct btrfs_ioctl_quota_ctl_args *sa;
5121         struct btrfs_trans_handle *trans = NULL;
5122         int ret;
5123         int err;
5124
5125         if (!capable(CAP_SYS_ADMIN))
5126                 return -EPERM;
5127
5128         ret = mnt_want_write_file(file);
5129         if (ret)
5130                 return ret;
5131
5132         sa = memdup_user(arg, sizeof(*sa));
5133         if (IS_ERR(sa)) {
5134                 ret = PTR_ERR(sa);
5135                 goto drop_write;
5136         }
5137
5138         down_write(&fs_info->subvol_sem);
5139         trans = btrfs_start_transaction(fs_info->tree_root, 2);
5140         if (IS_ERR(trans)) {
5141                 ret = PTR_ERR(trans);
5142                 goto out;
5143         }
5144
5145         switch (sa->cmd) {
5146         case BTRFS_QUOTA_CTL_ENABLE:
5147                 ret = btrfs_quota_enable(trans, fs_info);
5148                 break;
5149         case BTRFS_QUOTA_CTL_DISABLE:
5150                 ret = btrfs_quota_disable(trans, fs_info);
5151                 break;
5152         default:
5153                 ret = -EINVAL;
5154                 break;
5155         }
5156
5157         err = btrfs_commit_transaction(trans);
5158         if (err && !ret)
5159                 ret = err;
5160 out:
5161         kfree(sa);
5162         up_write(&fs_info->subvol_sem);
5163 drop_write:
5164         mnt_drop_write_file(file);
5165         return ret;
5166 }
5167
5168 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
5169 {
5170         struct inode *inode = file_inode(file);
5171         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5172         struct btrfs_root *root = BTRFS_I(inode)->root;
5173         struct btrfs_ioctl_qgroup_assign_args *sa;
5174         struct btrfs_trans_handle *trans;
5175         int ret;
5176         int err;
5177
5178         if (!capable(CAP_SYS_ADMIN))
5179                 return -EPERM;
5180
5181         ret = mnt_want_write_file(file);
5182         if (ret)
5183                 return ret;
5184
5185         sa = memdup_user(arg, sizeof(*sa));
5186         if (IS_ERR(sa)) {
5187                 ret = PTR_ERR(sa);
5188                 goto drop_write;
5189         }
5190
5191         trans = btrfs_join_transaction(root);
5192         if (IS_ERR(trans)) {
5193                 ret = PTR_ERR(trans);
5194                 goto out;
5195         }
5196
5197         if (sa->assign) {
5198                 ret = btrfs_add_qgroup_relation(trans, fs_info,
5199                                                 sa->src, sa->dst);
5200         } else {
5201                 ret = btrfs_del_qgroup_relation(trans, fs_info,
5202                                                 sa->src, sa->dst);
5203         }
5204
5205         /* update qgroup status and info */
5206         err = btrfs_run_qgroups(trans, fs_info);
5207         if (err < 0)
5208                 btrfs_handle_fs_error(fs_info, err,
5209                                       "failed to update qgroup status and info");
5210         err = btrfs_end_transaction(trans);
5211         if (err && !ret)
5212                 ret = err;
5213
5214 out:
5215         kfree(sa);
5216 drop_write:
5217         mnt_drop_write_file(file);
5218         return ret;
5219 }
5220
5221 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
5222 {
5223         struct inode *inode = file_inode(file);
5224         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5225         struct btrfs_root *root = BTRFS_I(inode)->root;
5226         struct btrfs_ioctl_qgroup_create_args *sa;
5227         struct btrfs_trans_handle *trans;
5228         int ret;
5229         int err;
5230
5231         if (!capable(CAP_SYS_ADMIN))
5232                 return -EPERM;
5233
5234         ret = mnt_want_write_file(file);
5235         if (ret)
5236                 return ret;
5237
5238         sa = memdup_user(arg, sizeof(*sa));
5239         if (IS_ERR(sa)) {
5240                 ret = PTR_ERR(sa);
5241                 goto drop_write;
5242         }
5243
5244         if (!sa->qgroupid) {
5245                 ret = -EINVAL;
5246                 goto out;
5247         }
5248
5249         trans = btrfs_join_transaction(root);
5250         if (IS_ERR(trans)) {
5251                 ret = PTR_ERR(trans);
5252                 goto out;
5253         }
5254
5255         if (sa->create) {
5256                 ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
5257         } else {
5258                 ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
5259         }
5260
5261         err = btrfs_end_transaction(trans);
5262         if (err && !ret)
5263                 ret = err;
5264
5265 out:
5266         kfree(sa);
5267 drop_write:
5268         mnt_drop_write_file(file);
5269         return ret;
5270 }
5271
5272 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
5273 {
5274         struct inode *inode = file_inode(file);
5275         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5276         struct btrfs_root *root = BTRFS_I(inode)->root;
5277         struct btrfs_ioctl_qgroup_limit_args *sa;
5278         struct btrfs_trans_handle *trans;
5279         int ret;
5280         int err;
5281         u64 qgroupid;
5282
5283         if (!capable(CAP_SYS_ADMIN))
5284                 return -EPERM;
5285
5286         ret = mnt_want_write_file(file);
5287         if (ret)
5288                 return ret;
5289
5290         sa = memdup_user(arg, sizeof(*sa));
5291         if (IS_ERR(sa)) {
5292                 ret = PTR_ERR(sa);
5293                 goto drop_write;
5294         }
5295
5296         trans = btrfs_join_transaction(root);
5297         if (IS_ERR(trans)) {
5298                 ret = PTR_ERR(trans);
5299                 goto out;
5300         }
5301
5302         qgroupid = sa->qgroupid;
5303         if (!qgroupid) {
5304                 /* take the current subvol as qgroup */
5305                 qgroupid = root->root_key.objectid;
5306         }
5307
5308         ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
5309
5310         err = btrfs_end_transaction(trans);
5311         if (err && !ret)
5312                 ret = err;
5313
5314 out:
5315         kfree(sa);
5316 drop_write:
5317         mnt_drop_write_file(file);
5318         return ret;
5319 }
5320
5321 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5322 {
5323         struct inode *inode = file_inode(file);
5324         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5325         struct btrfs_ioctl_quota_rescan_args *qsa;
5326         int ret;
5327
5328         if (!capable(CAP_SYS_ADMIN))
5329                 return -EPERM;
5330
5331         ret = mnt_want_write_file(file);
5332         if (ret)
5333                 return ret;
5334
5335         qsa = memdup_user(arg, sizeof(*qsa));
5336         if (IS_ERR(qsa)) {
5337                 ret = PTR_ERR(qsa);
5338                 goto drop_write;
5339         }
5340
5341         if (qsa->flags) {
5342                 ret = -EINVAL;
5343                 goto out;
5344         }
5345
5346         ret = btrfs_qgroup_rescan(fs_info);
5347
5348 out:
5349         kfree(qsa);
5350 drop_write:
5351         mnt_drop_write_file(file);
5352         return ret;
5353 }
5354
5355 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5356 {
5357         struct inode *inode = file_inode(file);
5358         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5359         struct btrfs_ioctl_quota_rescan_args *qsa;
5360         int ret = 0;
5361
5362         if (!capable(CAP_SYS_ADMIN))
5363                 return -EPERM;
5364
5365         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5366         if (!qsa)
5367                 return -ENOMEM;
5368
5369         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5370                 qsa->flags = 1;
5371                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5372         }
5373
5374         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5375                 ret = -EFAULT;
5376
5377         kfree(qsa);
5378         return ret;
5379 }
5380
5381 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5382 {
5383         struct inode *inode = file_inode(file);
5384         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5385
5386         if (!capable(CAP_SYS_ADMIN))
5387                 return -EPERM;
5388
5389         return btrfs_qgroup_wait_for_completion(fs_info, true);
5390 }
5391
5392 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5393                                             struct btrfs_ioctl_received_subvol_args *sa)
5394 {
5395         struct inode *inode = file_inode(file);
5396         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5397         struct btrfs_root *root = BTRFS_I(inode)->root;
5398         struct btrfs_root_item *root_item = &root->root_item;
5399         struct btrfs_trans_handle *trans;
5400         struct timespec64 ct = current_time(inode);
5401         int ret = 0;
5402         int received_uuid_changed;
5403
5404         if (!inode_owner_or_capable(inode))
5405                 return -EPERM;
5406
5407         ret = mnt_want_write_file(file);
5408         if (ret < 0)
5409                 return ret;
5410
5411         down_write(&fs_info->subvol_sem);
5412
5413         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5414                 ret = -EINVAL;
5415                 goto out;
5416         }
5417
5418         if (btrfs_root_readonly(root)) {
5419                 ret = -EROFS;
5420                 goto out;
5421         }
5422
5423         /*
5424          * 1 - root item
5425          * 2 - uuid items (received uuid + subvol uuid)
5426          */
5427         trans = btrfs_start_transaction(root, 3);
5428         if (IS_ERR(trans)) {
5429                 ret = PTR_ERR(trans);
5430                 trans = NULL;
5431                 goto out;
5432         }
5433
5434         sa->rtransid = trans->transid;
5435         sa->rtime.sec = ct.tv_sec;
5436         sa->rtime.nsec = ct.tv_nsec;
5437
5438         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5439                                        BTRFS_UUID_SIZE);
5440         if (received_uuid_changed &&
5441             !btrfs_is_empty_uuid(root_item->received_uuid)) {
5442                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5443                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5444                                           root->root_key.objectid);
5445                 if (ret && ret != -ENOENT) {
5446                         btrfs_abort_transaction(trans, ret);
5447                         btrfs_end_transaction(trans);
5448                         goto out;
5449                 }
5450         }
5451         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5452         btrfs_set_root_stransid(root_item, sa->stransid);
5453         btrfs_set_root_rtransid(root_item, sa->rtransid);
5454         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5455         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5456         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5457         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5458
5459         ret = btrfs_update_root(trans, fs_info->tree_root,
5460                                 &root->root_key, &root->root_item);
5461         if (ret < 0) {
5462                 btrfs_end_transaction(trans);
5463                 goto out;
5464         }
5465         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5466                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
5467                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5468                                           root->root_key.objectid);
5469                 if (ret < 0 && ret != -EEXIST) {
5470                         btrfs_abort_transaction(trans, ret);
5471                         btrfs_end_transaction(trans);
5472                         goto out;
5473                 }
5474         }
5475         ret = btrfs_commit_transaction(trans);
5476 out:
5477         up_write(&fs_info->subvol_sem);
5478         mnt_drop_write_file(file);
5479         return ret;
5480 }
5481
5482 #ifdef CONFIG_64BIT
5483 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5484                                                 void __user *arg)
5485 {
5486         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5487         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5488         int ret = 0;
5489
5490         args32 = memdup_user(arg, sizeof(*args32));
5491         if (IS_ERR(args32))
5492                 return PTR_ERR(args32);
5493
5494         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5495         if (!args64) {
5496                 ret = -ENOMEM;
5497                 goto out;
5498         }
5499
5500         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5501         args64->stransid = args32->stransid;
5502         args64->rtransid = args32->rtransid;
5503         args64->stime.sec = args32->stime.sec;
5504         args64->stime.nsec = args32->stime.nsec;
5505         args64->rtime.sec = args32->rtime.sec;
5506         args64->rtime.nsec = args32->rtime.nsec;
5507         args64->flags = args32->flags;
5508
5509         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5510         if (ret)
5511                 goto out;
5512
5513         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5514         args32->stransid = args64->stransid;
5515         args32->rtransid = args64->rtransid;
5516         args32->stime.sec = args64->stime.sec;
5517         args32->stime.nsec = args64->stime.nsec;
5518         args32->rtime.sec = args64->rtime.sec;
5519         args32->rtime.nsec = args64->rtime.nsec;
5520         args32->flags = args64->flags;
5521
5522         ret = copy_to_user(arg, args32, sizeof(*args32));
5523         if (ret)
5524                 ret = -EFAULT;
5525
5526 out:
5527         kfree(args32);
5528         kfree(args64);
5529         return ret;
5530 }
5531 #endif
5532
5533 static long btrfs_ioctl_set_received_subvol(struct file *file,
5534                                             void __user *arg)
5535 {
5536         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5537         int ret = 0;
5538
5539         sa = memdup_user(arg, sizeof(*sa));
5540         if (IS_ERR(sa))
5541                 return PTR_ERR(sa);
5542
5543         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5544
5545         if (ret)
5546                 goto out;
5547
5548         ret = copy_to_user(arg, sa, sizeof(*sa));
5549         if (ret)
5550                 ret = -EFAULT;
5551
5552 out:
5553         kfree(sa);
5554         return ret;
5555 }
5556
5557 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5558 {
5559         struct inode *inode = file_inode(file);
5560         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5561         size_t len;
5562         int ret;
5563         char label[BTRFS_LABEL_SIZE];
5564
5565         spin_lock(&fs_info->super_lock);
5566         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5567         spin_unlock(&fs_info->super_lock);
5568
5569         len = strnlen(label, BTRFS_LABEL_SIZE);
5570
5571         if (len == BTRFS_LABEL_SIZE) {
5572                 btrfs_warn(fs_info,
5573                            "label is too long, return the first %zu bytes",
5574                            --len);
5575         }
5576
5577         ret = copy_to_user(arg, label, len);
5578
5579         return ret ? -EFAULT : 0;
5580 }
5581
5582 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5583 {
5584         struct inode *inode = file_inode(file);
5585         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5586         struct btrfs_root *root = BTRFS_I(inode)->root;
5587         struct btrfs_super_block *super_block = fs_info->super_copy;
5588         struct btrfs_trans_handle *trans;
5589         char label[BTRFS_LABEL_SIZE];
5590         int ret;
5591
5592         if (!capable(CAP_SYS_ADMIN))
5593                 return -EPERM;
5594
5595         if (copy_from_user(label, arg, sizeof(label)))
5596                 return -EFAULT;
5597
5598         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5599                 btrfs_err(fs_info,
5600                           "unable to set label with more than %d bytes",
5601                           BTRFS_LABEL_SIZE - 1);
5602                 return -EINVAL;
5603         }
5604
5605         ret = mnt_want_write_file(file);
5606         if (ret)
5607                 return ret;
5608
5609         trans = btrfs_start_transaction(root, 0);
5610         if (IS_ERR(trans)) {
5611                 ret = PTR_ERR(trans);
5612                 goto out_unlock;
5613         }
5614
5615         spin_lock(&fs_info->super_lock);
5616         strcpy(super_block->label, label);
5617         spin_unlock(&fs_info->super_lock);
5618         ret = btrfs_commit_transaction(trans);
5619
5620 out_unlock:
5621         mnt_drop_write_file(file);
5622         return ret;
5623 }
5624
5625 #define INIT_FEATURE_FLAGS(suffix) \
5626         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5627           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5628           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5629
5630 int btrfs_ioctl_get_supported_features(void __user *arg)
5631 {
5632         static const struct btrfs_ioctl_feature_flags features[3] = {
5633                 INIT_FEATURE_FLAGS(SUPP),
5634                 INIT_FEATURE_FLAGS(SAFE_SET),
5635                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5636         };
5637
5638         if (copy_to_user(arg, &features, sizeof(features)))
5639                 return -EFAULT;
5640
5641         return 0;
5642 }
5643
5644 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5645 {
5646         struct inode *inode = file_inode(file);
5647         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5648         struct btrfs_super_block *super_block = fs_info->super_copy;
5649         struct btrfs_ioctl_feature_flags features;
5650
5651         features.compat_flags = btrfs_super_compat_flags(super_block);
5652         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5653         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5654
5655         if (copy_to_user(arg, &features, sizeof(features)))
5656                 return -EFAULT;
5657
5658         return 0;
5659 }
5660
5661 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5662                               enum btrfs_feature_set set,
5663                               u64 change_mask, u64 flags, u64 supported_flags,
5664                               u64 safe_set, u64 safe_clear)
5665 {
5666         const char *type = btrfs_feature_set_names[set];
5667         char *names;
5668         u64 disallowed, unsupported;
5669         u64 set_mask = flags & change_mask;
5670         u64 clear_mask = ~flags & change_mask;
5671
5672         unsupported = set_mask & ~supported_flags;
5673         if (unsupported) {
5674                 names = btrfs_printable_features(set, unsupported);
5675                 if (names) {
5676                         btrfs_warn(fs_info,
5677                                    "this kernel does not support the %s feature bit%s",
5678                                    names, strchr(names, ',') ? "s" : "");
5679                         kfree(names);
5680                 } else
5681                         btrfs_warn(fs_info,
5682                                    "this kernel does not support %s bits 0x%llx",
5683                                    type, unsupported);
5684                 return -EOPNOTSUPP;
5685         }
5686
5687         disallowed = set_mask & ~safe_set;
5688         if (disallowed) {
5689                 names = btrfs_printable_features(set, disallowed);
5690                 if (names) {
5691                         btrfs_warn(fs_info,
5692                                    "can't set the %s feature bit%s while mounted",
5693                                    names, strchr(names, ',') ? "s" : "");
5694                         kfree(names);
5695                 } else
5696                         btrfs_warn(fs_info,
5697                                    "can't set %s bits 0x%llx while mounted",
5698                                    type, disallowed);
5699                 return -EPERM;
5700         }
5701
5702         disallowed = clear_mask & ~safe_clear;
5703         if (disallowed) {
5704                 names = btrfs_printable_features(set, disallowed);
5705                 if (names) {
5706                         btrfs_warn(fs_info,
5707                                    "can't clear the %s feature bit%s while mounted",
5708                                    names, strchr(names, ',') ? "s" : "");
5709                         kfree(names);
5710                 } else
5711                         btrfs_warn(fs_info,
5712                                    "can't clear %s bits 0x%llx while mounted",
5713                                    type, disallowed);
5714                 return -EPERM;
5715         }
5716
5717         return 0;
5718 }
5719
5720 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5721 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5722                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5723                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5724                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5725
5726 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5727 {
5728         struct inode *inode = file_inode(file);
5729         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5730         struct btrfs_root *root = BTRFS_I(inode)->root;
5731         struct btrfs_super_block *super_block = fs_info->super_copy;
5732         struct btrfs_ioctl_feature_flags flags[2];
5733         struct btrfs_trans_handle *trans;
5734         u64 newflags;
5735         int ret;
5736
5737         if (!capable(CAP_SYS_ADMIN))
5738                 return -EPERM;
5739
5740         if (copy_from_user(flags, arg, sizeof(flags)))
5741                 return -EFAULT;
5742
5743         /* Nothing to do */
5744         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5745             !flags[0].incompat_flags)
5746                 return 0;
5747
5748         ret = check_feature(fs_info, flags[0].compat_flags,
5749                             flags[1].compat_flags, COMPAT);
5750         if (ret)
5751                 return ret;
5752
5753         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5754                             flags[1].compat_ro_flags, COMPAT_RO);
5755         if (ret)
5756                 return ret;
5757
5758         ret = check_feature(fs_info, flags[0].incompat_flags,
5759                             flags[1].incompat_flags, INCOMPAT);
5760         if (ret)
5761                 return ret;
5762
5763         ret = mnt_want_write_file(file);
5764         if (ret)
5765                 return ret;
5766
5767         trans = btrfs_start_transaction(root, 0);
5768         if (IS_ERR(trans)) {
5769                 ret = PTR_ERR(trans);
5770                 goto out_drop_write;
5771         }
5772
5773         spin_lock(&fs_info->super_lock);
5774         newflags = btrfs_super_compat_flags(super_block);
5775         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5776         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5777         btrfs_set_super_compat_flags(super_block, newflags);
5778
5779         newflags = btrfs_super_compat_ro_flags(super_block);
5780         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5781         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5782         btrfs_set_super_compat_ro_flags(super_block, newflags);
5783
5784         newflags = btrfs_super_incompat_flags(super_block);
5785         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5786         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5787         btrfs_set_super_incompat_flags(super_block, newflags);
5788         spin_unlock(&fs_info->super_lock);
5789
5790         ret = btrfs_commit_transaction(trans);
5791 out_drop_write:
5792         mnt_drop_write_file(file);
5793
5794         return ret;
5795 }
5796
5797 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5798 {
5799         struct btrfs_ioctl_send_args *arg;
5800         int ret;
5801
5802         if (compat) {
5803 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5804                 struct btrfs_ioctl_send_args_32 args32;
5805
5806                 ret = copy_from_user(&args32, argp, sizeof(args32));
5807                 if (ret)
5808                         return -EFAULT;
5809                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5810                 if (!arg)
5811                         return -ENOMEM;
5812                 arg->send_fd = args32.send_fd;
5813                 arg->clone_sources_count = args32.clone_sources_count;
5814                 arg->clone_sources = compat_ptr(args32.clone_sources);
5815                 arg->parent_root = args32.parent_root;
5816                 arg->flags = args32.flags;
5817                 memcpy(arg->reserved, args32.reserved,
5818                        sizeof(args32.reserved));
5819 #else
5820                 return -ENOTTY;
5821 #endif
5822         } else {
5823                 arg = memdup_user(argp, sizeof(*arg));
5824                 if (IS_ERR(arg))
5825                         return PTR_ERR(arg);
5826         }
5827         ret = btrfs_ioctl_send(file, arg);
5828         kfree(arg);
5829         return ret;
5830 }
5831
5832 long btrfs_ioctl(struct file *file, unsigned int
5833                 cmd, unsigned long arg)
5834 {
5835         struct inode *inode = file_inode(file);
5836         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5837         struct btrfs_root *root = BTRFS_I(inode)->root;
5838         void __user *argp = (void __user *)arg;
5839
5840         switch (cmd) {
5841         case FS_IOC_GETFLAGS:
5842                 return btrfs_ioctl_getflags(file, argp);
5843         case FS_IOC_SETFLAGS:
5844                 return btrfs_ioctl_setflags(file, argp);
5845         case FS_IOC_GETVERSION:
5846                 return btrfs_ioctl_getversion(file, argp);
5847         case FITRIM:
5848                 return btrfs_ioctl_fitrim(file, argp);
5849         case BTRFS_IOC_SNAP_CREATE:
5850                 return btrfs_ioctl_snap_create(file, argp, 0);
5851         case BTRFS_IOC_SNAP_CREATE_V2:
5852                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5853         case BTRFS_IOC_SUBVOL_CREATE:
5854                 return btrfs_ioctl_snap_create(file, argp, 1);
5855         case BTRFS_IOC_SUBVOL_CREATE_V2:
5856                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5857         case BTRFS_IOC_SNAP_DESTROY:
5858                 return btrfs_ioctl_snap_destroy(file, argp);
5859         case BTRFS_IOC_SUBVOL_GETFLAGS:
5860                 return btrfs_ioctl_subvol_getflags(file, argp);
5861         case BTRFS_IOC_SUBVOL_SETFLAGS:
5862                 return btrfs_ioctl_subvol_setflags(file, argp);
5863         case BTRFS_IOC_DEFAULT_SUBVOL:
5864                 return btrfs_ioctl_default_subvol(file, argp);
5865         case BTRFS_IOC_DEFRAG:
5866                 return btrfs_ioctl_defrag(file, NULL);
5867         case BTRFS_IOC_DEFRAG_RANGE:
5868                 return btrfs_ioctl_defrag(file, argp);
5869         case BTRFS_IOC_RESIZE:
5870                 return btrfs_ioctl_resize(file, argp);
5871         case BTRFS_IOC_ADD_DEV:
5872                 return btrfs_ioctl_add_dev(fs_info, argp);
5873         case BTRFS_IOC_RM_DEV:
5874                 return btrfs_ioctl_rm_dev(file, argp);
5875         case BTRFS_IOC_RM_DEV_V2:
5876                 return btrfs_ioctl_rm_dev_v2(file, argp);
5877         case BTRFS_IOC_FS_INFO:
5878                 return btrfs_ioctl_fs_info(fs_info, argp);
5879         case BTRFS_IOC_DEV_INFO:
5880                 return btrfs_ioctl_dev_info(fs_info, argp);
5881         case BTRFS_IOC_BALANCE:
5882                 return btrfs_ioctl_balance(file, NULL);
5883         case BTRFS_IOC_TREE_SEARCH:
5884                 return btrfs_ioctl_tree_search(file, argp);
5885         case BTRFS_IOC_TREE_SEARCH_V2:
5886                 return btrfs_ioctl_tree_search_v2(file, argp);
5887         case BTRFS_IOC_INO_LOOKUP:
5888                 return btrfs_ioctl_ino_lookup(file, argp);
5889         case BTRFS_IOC_INO_PATHS:
5890                 return btrfs_ioctl_ino_to_path(root, argp);
5891         case BTRFS_IOC_LOGICAL_INO:
5892                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5893         case BTRFS_IOC_LOGICAL_INO_V2:
5894                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5895         case BTRFS_IOC_SPACE_INFO:
5896                 return btrfs_ioctl_space_info(fs_info, argp);
5897         case BTRFS_IOC_SYNC: {
5898                 int ret;
5899
5900                 ret = btrfs_start_delalloc_roots(fs_info, -1);
5901                 if (ret)
5902                         return ret;
5903                 ret = btrfs_sync_fs(inode->i_sb, 1);
5904                 /*
5905                  * The transaction thread may want to do more work,
5906                  * namely it pokes the cleaner kthread that will start
5907                  * processing uncleaned subvols.
5908                  */
5909                 wake_up_process(fs_info->transaction_kthread);
5910                 return ret;
5911         }
5912         case BTRFS_IOC_START_SYNC:
5913                 return btrfs_ioctl_start_sync(root, argp);
5914         case BTRFS_IOC_WAIT_SYNC:
5915                 return btrfs_ioctl_wait_sync(fs_info, argp);
5916         case BTRFS_IOC_SCRUB:
5917                 return btrfs_ioctl_scrub(file, argp);
5918         case BTRFS_IOC_SCRUB_CANCEL:
5919                 return btrfs_ioctl_scrub_cancel(fs_info);
5920         case BTRFS_IOC_SCRUB_PROGRESS:
5921                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5922         case BTRFS_IOC_BALANCE_V2:
5923                 return btrfs_ioctl_balance(file, argp);
5924         case BTRFS_IOC_BALANCE_CTL:
5925                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5926         case BTRFS_IOC_BALANCE_PROGRESS:
5927                 return btrfs_ioctl_balance_progress(fs_info, argp);
5928         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5929                 return btrfs_ioctl_set_received_subvol(file, argp);
5930 #ifdef CONFIG_64BIT
5931         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5932                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5933 #endif
5934         case BTRFS_IOC_SEND:
5935                 return _btrfs_ioctl_send(file, argp, false);
5936 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5937         case BTRFS_IOC_SEND_32:
5938                 return _btrfs_ioctl_send(file, argp, true);
5939 #endif
5940         case BTRFS_IOC_GET_DEV_STATS:
5941                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5942         case BTRFS_IOC_QUOTA_CTL:
5943                 return btrfs_ioctl_quota_ctl(file, argp);
5944         case BTRFS_IOC_QGROUP_ASSIGN:
5945                 return btrfs_ioctl_qgroup_assign(file, argp);
5946         case BTRFS_IOC_QGROUP_CREATE:
5947                 return btrfs_ioctl_qgroup_create(file, argp);
5948         case BTRFS_IOC_QGROUP_LIMIT:
5949                 return btrfs_ioctl_qgroup_limit(file, argp);
5950         case BTRFS_IOC_QUOTA_RESCAN:
5951                 return btrfs_ioctl_quota_rescan(file, argp);
5952         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5953                 return btrfs_ioctl_quota_rescan_status(file, argp);
5954         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5955                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5956         case BTRFS_IOC_DEV_REPLACE:
5957                 return btrfs_ioctl_dev_replace(fs_info, argp);
5958         case BTRFS_IOC_GET_FSLABEL:
5959                 return btrfs_ioctl_get_fslabel(file, argp);
5960         case BTRFS_IOC_SET_FSLABEL:
5961                 return btrfs_ioctl_set_fslabel(file, argp);
5962         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5963                 return btrfs_ioctl_get_supported_features(argp);
5964         case BTRFS_IOC_GET_FEATURES:
5965                 return btrfs_ioctl_get_features(file, argp);
5966         case BTRFS_IOC_SET_FEATURES:
5967                 return btrfs_ioctl_set_features(file, argp);
5968         case FS_IOC_FSGETXATTR:
5969                 return btrfs_ioctl_fsgetxattr(file, argp);
5970         case FS_IOC_FSSETXATTR:
5971                 return btrfs_ioctl_fssetxattr(file, argp);
5972         case BTRFS_IOC_GET_SUBVOL_INFO:
5973                 return btrfs_ioctl_get_subvol_info(file, argp);
5974         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5975                 return btrfs_ioctl_get_subvol_rootref(file, argp);
5976         case BTRFS_IOC_INO_LOOKUP_USER:
5977                 return btrfs_ioctl_ino_lookup_user(file, argp);
5978         }
5979
5980         return -ENOTTY;
5981 }
5982
5983 #ifdef CONFIG_COMPAT
5984 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5985 {
5986         /*
5987          * These all access 32-bit values anyway so no further
5988          * handling is necessary.
5989          */
5990         switch (cmd) {
5991         case FS_IOC32_GETFLAGS:
5992                 cmd = FS_IOC_GETFLAGS;
5993                 break;
5994         case FS_IOC32_SETFLAGS:
5995                 cmd = FS_IOC_SETFLAGS;
5996                 break;
5997         case FS_IOC32_GETVERSION:
5998                 cmd = FS_IOC_GETVERSION;
5999                 break;
6000         }
6001
6002         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
6003 }
6004 #endif