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/file.h>
   9 #include <linux/fs.h>
  10 #include <linux/fsnotify.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/highmem.h>
  13 #include <linux/time.h>
  14 #include <linux/string.h>
  15 #include <linux/backing-dev.h>
  16 #include <linux/mount.h>
  17 #include <linux/namei.h>
  18 #include <linux/writeback.h>
  19 #include <linux/compat.h>
  20 #include <linux/security.h>
  21 #include <linux/xattr.h>
  22 #include <linux/mm.h>
  23 #include <linux/slab.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/uuid.h>
  26 #include <linux/btrfs.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/iversion.h>
  29 #include "ctree.h"
  30 #include "disk-io.h"
  31 #include "export.h"
  32 #include "transaction.h"
  33 #include "btrfs_inode.h"
  34 #include "print-tree.h"
  35 #include "volumes.h"
  36 #include "locking.h"
  37 #include "inode-map.h"
  38 #include "backref.h"
  39 #include "rcu-string.h"
  40 #include "send.h"
  41 #include "dev-replace.h"
  42 #include "props.h"
  43 #include "sysfs.h"
  44 #include "qgroup.h"
  45 #include "tree-log.h"
  46 #include "compression.h"
  47 #include "space-info.h"
  48 #include "delalloc-space.h"
  49 #include "block-group.h"
  50
  51 #ifdef CONFIG_64BIT
  52 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  53  * structures are incorrect, as the timespec structure from userspace
  54  * is 4 bytes too small. We define these alternatives here to teach
  55  * the kernel about the 32-bit struct packing.
  56  */
  57 struct btrfs_ioctl_timespec_32 {
  58         __u64 sec;
  59         __u32 nsec;
  60 } __attribute__ ((__packed__));
  61
  62 struct btrfs_ioctl_received_subvol_args_32 {
  63         char    uuid[BTRFS_UUID_SIZE];  /* in */
  64         __u64   stransid;               /* in */
  65         __u64   rtransid;               /* out */
  66         struct btrfs_ioctl_timespec_32 stime; /* in */
  67         struct btrfs_ioctl_timespec_32 rtime; /* out */
  68         __u64   flags;                  /* in */
  69         __u64   reserved[16];           /* in */
  70 } __attribute__ ((__packed__));
  71
  72 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  73                                 struct btrfs_ioctl_received_subvol_args_32)
  74 #endif
  75
  76 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  77 struct btrfs_ioctl_send_args_32 {
  78         __s64 send_fd;                  /* in */
  79         __u64 clone_sources_count;      /* in */
  80         compat_uptr_t clone_sources;    /* in */
  81         __u64 parent_root;              /* in */
  82         __u64 flags;                    /* in */
  83         __u64 reserved[4];              /* in */
  84 } __attribute__ ((__packed__));
  85
  86 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  87                                struct btrfs_ioctl_send_args_32)
  88 #endif
  89
  90 /* Mask out flags that are inappropriate for the given type of inode. */
  91 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
  92                 unsigned int flags)
  93 {
  94         if (S_ISDIR(inode->i_mode))
  95                 return flags;
  96         else if (S_ISREG(inode->i_mode))
  97                 return flags & ~FS_DIRSYNC_FL;
  98         else
  99                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 100 }
 101
 102 /*
 103  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 104  * ioctl.
 105  */
 106 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
 107 {
 108         unsigned int iflags = 0;
 109
 110         if (flags & BTRFS_INODE_SYNC)
 111                 iflags |= FS_SYNC_FL;
 112         if (flags & BTRFS_INODE_IMMUTABLE)
 113                 iflags |= FS_IMMUTABLE_FL;
 114         if (flags & BTRFS_INODE_APPEND)
 115                 iflags |= FS_APPEND_FL;
 116         if (flags & BTRFS_INODE_NODUMP)
 117                 iflags |= FS_NODUMP_FL;
 118         if (flags & BTRFS_INODE_NOATIME)
 119                 iflags |= FS_NOATIME_FL;
 120         if (flags & BTRFS_INODE_DIRSYNC)
 121                 iflags |= FS_DIRSYNC_FL;
 122         if (flags & BTRFS_INODE_NODATACOW)
 123                 iflags |= FS_NOCOW_FL;
 124
 125         if (flags & BTRFS_INODE_NOCOMPRESS)
 126                 iflags |= FS_NOCOMP_FL;
 127         else if (flags & BTRFS_INODE_COMPRESS)
 128                 iflags |= FS_COMPR_FL;
 129
 130         return iflags;
 131 }
 132
 133 /*
 134  * Update inode->i_flags based on the btrfs internal flags.
 135  */
 136 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 137 {
 138         struct btrfs_inode *binode = BTRFS_I(inode);
 139         unsigned int new_fl = 0;
 140
 141         if (binode->flags & BTRFS_INODE_SYNC)
 142                 new_fl |= S_SYNC;
 143         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 144                 new_fl |= S_IMMUTABLE;
 145         if (binode->flags & BTRFS_INODE_APPEND)
 146                 new_fl |= S_APPEND;
 147         if (binode->flags & BTRFS_INODE_NOATIME)
 148                 new_fl |= S_NOATIME;
 149         if (binode->flags & BTRFS_INODE_DIRSYNC)
 150                 new_fl |= S_DIRSYNC;
 151
 152         set_mask_bits(&inode->i_flags,
 153                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 154                       new_fl);
 155 }
 156
 157 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 158 {
 159         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 160         unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
 161
 162         if (copy_to_user(arg, &flags, sizeof(flags)))
 163                 return -EFAULT;
 164         return 0;
 165 }
 166
 167 /* Check if @flags are a supported and valid set of FS_*_FL flags */
 168 static int check_fsflags(unsigned int flags)
 169 {
 170         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 171                       FS_NOATIME_FL | FS_NODUMP_FL | \
 172                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 173                       FS_NOCOMP_FL | FS_COMPR_FL |
 174                       FS_NOCOW_FL))
 175                 return -EOPNOTSUPP;
 176
 177         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 178                 return -EINVAL;
 179
 180         return 0;
 181 }
 182
 183 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 184 {
 185         struct inode *inode = file_inode(file);
 186         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 187         struct btrfs_inode *binode = BTRFS_I(inode);
 188         struct btrfs_root *root = binode->root;
 189         struct btrfs_trans_handle *trans;
 190         unsigned int fsflags, old_fsflags;
 191         int ret;
 192         const char *comp = NULL;
 193         u32 binode_flags = binode->flags;
 194
 195         if (!inode_owner_or_capable(inode))
 196                 return -EPERM;
 197
 198         if (btrfs_root_readonly(root))
 199                 return -EROFS;
 200
 201         if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
 202                 return -EFAULT;
 203
 204         ret = check_fsflags(fsflags);
 205         if (ret)
 206                 return ret;
 207
 208         ret = mnt_want_write_file(file);
 209         if (ret)
 210                 return ret;
 211
 212         inode_lock(inode);
 213
 214         fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
 215         old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
 216         ret = vfs_ioc_setflags_prepare(inode, old_fsflags, fsflags);
 217         if (ret)
 218                 goto out_unlock;
 219
 220         if (fsflags & FS_SYNC_FL)
 221                 binode_flags |= BTRFS_INODE_SYNC;
 222         else
 223                 binode_flags &= ~BTRFS_INODE_SYNC;
 224         if (fsflags & FS_IMMUTABLE_FL)
 225                 binode_flags |= BTRFS_INODE_IMMUTABLE;
 226         else
 227                 binode_flags &= ~BTRFS_INODE_IMMUTABLE;
 228         if (fsflags & FS_APPEND_FL)
 229                 binode_flags |= BTRFS_INODE_APPEND;
 230         else
 231                 binode_flags &= ~BTRFS_INODE_APPEND;
 232         if (fsflags & FS_NODUMP_FL)
 233                 binode_flags |= BTRFS_INODE_NODUMP;
 234         else
 235                 binode_flags &= ~BTRFS_INODE_NODUMP;
 236         if (fsflags & FS_NOATIME_FL)
 237                 binode_flags |= BTRFS_INODE_NOATIME;
 238         else
 239                 binode_flags &= ~BTRFS_INODE_NOATIME;
 240         if (fsflags & FS_DIRSYNC_FL)
 241                 binode_flags |= BTRFS_INODE_DIRSYNC;
 242         else
 243                 binode_flags &= ~BTRFS_INODE_DIRSYNC;
 244         if (fsflags & FS_NOCOW_FL) {
 245                 if (S_ISREG(inode->i_mode)) {
 246                         /*
 247                          * It's safe to turn csums off here, no extents exist.
 248                          * Otherwise we want the flag to reflect the real COW
 249                          * status of the file and will not set it.
 250                          */
 251                         if (inode->i_size == 0)
 252                                 binode_flags |= BTRFS_INODE_NODATACOW |
 253                                                 BTRFS_INODE_NODATASUM;
 254                 } else {
 255                         binode_flags |= BTRFS_INODE_NODATACOW;
 256                 }
 257         } else {
 258                 /*
 259                  * Revert back under same assumptions as above
 260                  */
 261                 if (S_ISREG(inode->i_mode)) {
 262                         if (inode->i_size == 0)
 263                                 binode_flags &= ~(BTRFS_INODE_NODATACOW |
 264                                                   BTRFS_INODE_NODATASUM);
 265                 } else {
 266                         binode_flags &= ~BTRFS_INODE_NODATACOW;
 267                 }
 268         }
 269
 270         /*
 271          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 272          * flag may be changed automatically if compression code won't make
 273          * things smaller.
 274          */
 275         if (fsflags & FS_NOCOMP_FL) {
 276                 binode_flags &= ~BTRFS_INODE_COMPRESS;
 277                 binode_flags |= BTRFS_INODE_NOCOMPRESS;
 278         } else if (fsflags & FS_COMPR_FL) {
 279
 280                 if (IS_SWAPFILE(inode)) {
 281                         ret = -ETXTBSY;
 282                         goto out_unlock;
 283                 }
 284
 285                 binode_flags |= BTRFS_INODE_COMPRESS;
 286                 binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
 287
 288                 comp = btrfs_compress_type2str(fs_info->compress_type);
 289                 if (!comp || comp[0] == 0)
 290                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 291         } else {
 292                 binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 293         }
 294
 295         /*
 296          * 1 for inode item
 297          * 2 for properties
 298          */
 299         trans = btrfs_start_transaction(root, 3);
 300         if (IS_ERR(trans)) {
 301                 ret = PTR_ERR(trans);
 302                 goto out_unlock;
 303         }
 304
 305         if (comp) {
 306                 ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
 307                                      strlen(comp), 0);
 308                 if (ret) {
 309                         btrfs_abort_transaction(trans, ret);
 310                         goto out_end_trans;
 311                 }
 312         } else {
 313                 ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
 314                                      0, 0);
 315                 if (ret && ret != -ENODATA) {
 316                         btrfs_abort_transaction(trans, ret);
 317                         goto out_end_trans;
 318                 }
 319         }
 320
 321         binode->flags = binode_flags;
 322         btrfs_sync_inode_flags_to_i_flags(inode);
 323         inode_inc_iversion(inode);
 324         inode->i_ctime = current_time(inode);
 325         ret = btrfs_update_inode(trans, root, inode);
 326
 327  out_end_trans:
 328         btrfs_end_transaction(trans);
 329  out_unlock:
 330         inode_unlock(inode);
 331         mnt_drop_write_file(file);
 332         return ret;
 333 }
 334
 335 /*
 336  * Translate btrfs internal inode flags to xflags as expected by the
 337  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
 338  * silently dropped.
 339  */
 340 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
 341 {
 342         unsigned int xflags = 0;
 343
 344         if (flags & BTRFS_INODE_APPEND)
 345                 xflags |= FS_XFLAG_APPEND;
 346         if (flags & BTRFS_INODE_IMMUTABLE)
 347                 xflags |= FS_XFLAG_IMMUTABLE;
 348         if (flags & BTRFS_INODE_NOATIME)
 349                 xflags |= FS_XFLAG_NOATIME;
 350         if (flags & BTRFS_INODE_NODUMP)
 351                 xflags |= FS_XFLAG_NODUMP;
 352         if (flags & BTRFS_INODE_SYNC)
 353                 xflags |= FS_XFLAG_SYNC;
 354
 355         return xflags;
 356 }
 357
 358 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
 359 static int check_xflags(unsigned int flags)
 360 {
 361         if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
 362                       FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
 363                 return -EOPNOTSUPP;
 364         return 0;
 365 }
 366
 367 /*
 368  * Set the xflags from the internal inode flags. The remaining items of fsxattr
 369  * are zeroed.
 370  */
 371 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
 372 {
 373         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 374         struct fsxattr fa;
 375
 376         simple_fill_fsxattr(&fa, btrfs_inode_flags_to_xflags(binode->flags));
 377         if (copy_to_user(arg, &fa, sizeof(fa)))
 378                 return -EFAULT;
 379
 380         return 0;
 381 }
 382
 383 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
 384 {
 385         struct inode *inode = file_inode(file);
 386         struct btrfs_inode *binode = BTRFS_I(inode);
 387         struct btrfs_root *root = binode->root;
 388         struct btrfs_trans_handle *trans;
 389         struct fsxattr fa, old_fa;
 390         unsigned old_flags;
 391         unsigned old_i_flags;
 392         int ret = 0;
 393
 394         if (!inode_owner_or_capable(inode))
 395                 return -EPERM;
 396
 397         if (btrfs_root_readonly(root))
 398                 return -EROFS;
 399
 400         if (copy_from_user(&fa, arg, sizeof(fa)))
 401                 return -EFAULT;
 402
 403         ret = check_xflags(fa.fsx_xflags);
 404         if (ret)
 405                 return ret;
 406
 407         if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
 408                 return -EOPNOTSUPP;
 409
 410         ret = mnt_want_write_file(file);
 411         if (ret)
 412                 return ret;
 413
 414         inode_lock(inode);
 415
 416         old_flags = binode->flags;
 417         old_i_flags = inode->i_flags;
 418
 419         simple_fill_fsxattr(&old_fa,
 420                             btrfs_inode_flags_to_xflags(binode->flags));
 421         ret = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
 422         if (ret)
 423                 goto out_unlock;
 424
 425         if (fa.fsx_xflags & FS_XFLAG_SYNC)
 426                 binode->flags |= BTRFS_INODE_SYNC;
 427         else
 428                 binode->flags &= ~BTRFS_INODE_SYNC;
 429         if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
 430                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 431         else
 432                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 433         if (fa.fsx_xflags & FS_XFLAG_APPEND)
 434                 binode->flags |= BTRFS_INODE_APPEND;
 435         else
 436                 binode->flags &= ~BTRFS_INODE_APPEND;
 437         if (fa.fsx_xflags & FS_XFLAG_NODUMP)
 438                 binode->flags |= BTRFS_INODE_NODUMP;
 439         else
 440                 binode->flags &= ~BTRFS_INODE_NODUMP;
 441         if (fa.fsx_xflags & FS_XFLAG_NOATIME)
 442                 binode->flags |= BTRFS_INODE_NOATIME;
 443         else
 444                 binode->flags &= ~BTRFS_INODE_NOATIME;
 445
 446         /* 1 item for the inode */
 447         trans = btrfs_start_transaction(root, 1);
 448         if (IS_ERR(trans)) {
 449                 ret = PTR_ERR(trans);
 450                 goto out_unlock;
 451         }
 452
 453         btrfs_sync_inode_flags_to_i_flags(inode);
 454         inode_inc_iversion(inode);
 455         inode->i_ctime = current_time(inode);
 456         ret = btrfs_update_inode(trans, root, inode);
 457
 458         btrfs_end_transaction(trans);
 459
 460 out_unlock:
 461         if (ret) {
 462                 binode->flags = old_flags;
 463                 inode->i_flags = old_i_flags;
 464         }
 465
 466         inode_unlock(inode);
 467         mnt_drop_write_file(file);
 468
 469         return ret;
 470 }
 471
 472 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 473 {
 474         struct inode *inode = file_inode(file);
 475
 476         return put_user(inode->i_generation, arg);
 477 }
 478
 479 static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
 480                                         void __user *arg)
 481 {
 482         struct btrfs_device *device;
 483         struct request_queue *q;
 484         struct fstrim_range range;
 485         u64 minlen = ULLONG_MAX;
 486         u64 num_devices = 0;
 487         int ret;
 488
 489         if (!capable(CAP_SYS_ADMIN))
 490                 return -EPERM;
 491
 492         /*
 493          * If the fs is mounted with nologreplay, which requires it to be
 494          * mounted in RO mode as well, we can not allow discard on free space
 495          * inside block groups, because log trees refer to extents that are not
 496          * pinned in a block group's free space cache (pinning the extents is
 497          * precisely the first phase of replaying a log tree).
 498          */
 499         if (btrfs_test_opt(fs_info, NOLOGREPLAY))
 500                 return -EROFS;
 501
 502         rcu_read_lock();
 503         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 504                                 dev_list) {
 505                 if (!device->bdev)
 506                         continue;
 507                 q = bdev_get_queue(device->bdev);
 508                 if (blk_queue_discard(q)) {
 509                         num_devices++;
 510                         minlen = min_t(u64, q->limits.discard_granularity,
 511                                      minlen);
 512                 }
 513         }
 514         rcu_read_unlock();
 515
 516         if (!num_devices)
 517                 return -EOPNOTSUPP;
 518         if (copy_from_user(&range, arg, sizeof(range)))
 519                 return -EFAULT;
 520
 521         /*
 522          * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
 523          * block group is in the logical address space, which can be any
 524          * sectorsize aligned bytenr in  the range [0, U64_MAX].
 525          */
 526         if (range.len < fs_info->sb->s_blocksize)
 527                 return -EINVAL;
 528
 529         range.minlen = max(range.minlen, minlen);
 530         ret = btrfs_trim_fs(fs_info, &range);
 531         if (ret < 0)
 532                 return ret;
 533
 534         if (copy_to_user(arg, &range, sizeof(range)))
 535                 return -EFAULT;
 536
 537         return 0;
 538 }
 539
 540 int __pure btrfs_is_empty_uuid(u8 *uuid)
 541 {
 542         int i;
 543
 544         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 545                 if (uuid[i])
 546                         return 0;
 547         }
 548         return 1;
 549 }
 550
 551 static noinline int create_subvol(struct inode *dir,
 552                                   struct dentry *dentry,
 553                                   const char *name, int namelen,
 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
 573         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 574         if (!root_item)
 575                 return -ENOMEM;
 576
 577         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 578         if (ret)
 579                 goto fail_free;
 580
 581         /*
 582          * Don't create subvolume whose level is not zero. Or qgroup will be
 583          * screwed up since it assumes subvolume qgroup's level to be 0.
 584          */
 585         if (btrfs_qgroup_level(objectid)) {
 586                 ret = -ENOSPC;
 587                 goto fail_free;
 588         }
 589
 590         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 591         /*
 592          * The same as the snapshot creation, please see the comment
 593          * of create_snapshot().
 594          */
 595         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
 596         if (ret)
 597                 goto fail_free;
 598
 599         trans = btrfs_start_transaction(root, 0);
 600         if (IS_ERR(trans)) {
 601                 ret = PTR_ERR(trans);
 602                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 603                 goto fail_free;
 604         }
 605         trans->block_rsv = &block_rsv;
 606         trans->bytes_reserved = block_rsv.size;
 607
 608         ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
 609         if (ret)
 610                 goto fail;
 611
 612         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 613         if (IS_ERR(leaf)) {
 614                 ret = PTR_ERR(leaf);
 615                 goto fail;
 616         }
 617
 618         btrfs_mark_buffer_dirty(leaf);
 619
 620         inode_item = &root_item->inode;
 621         btrfs_set_stack_inode_generation(inode_item, 1);
 622         btrfs_set_stack_inode_size(inode_item, 3);
 623         btrfs_set_stack_inode_nlink(inode_item, 1);
 624         btrfs_set_stack_inode_nbytes(inode_item,
 625                                      fs_info->nodesize);
 626         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 627
 628         btrfs_set_root_flags(root_item, 0);
 629         btrfs_set_root_limit(root_item, 0);
 630         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 631
 632         btrfs_set_root_bytenr(root_item, leaf->start);
 633         btrfs_set_root_generation(root_item, trans->transid);
 634         btrfs_set_root_level(root_item, 0);
 635         btrfs_set_root_refs(root_item, 1);
 636         btrfs_set_root_used(root_item, leaf->len);
 637         btrfs_set_root_last_snapshot(root_item, 0);
 638
 639         btrfs_set_root_generation_v2(root_item,
 640                         btrfs_root_generation(root_item));
 641         generate_random_guid(root_item->uuid);
 642         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 643         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 644         root_item->ctime = root_item->otime;
 645         btrfs_set_root_ctransid(root_item, trans->transid);
 646         btrfs_set_root_otransid(root_item, trans->transid);
 647
 648         btrfs_tree_unlock(leaf);
 649         free_extent_buffer(leaf);
 650         leaf = NULL;
 651
 652         btrfs_set_root_dirid(root_item, new_dirid);
 653
 654         key.objectid = objectid;
 655         key.offset = 0;
 656         key.type = BTRFS_ROOT_ITEM_KEY;
 657         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 658                                 root_item);
 659         if (ret)
 660                 goto fail;
 661
 662         key.offset = (u64)-1;
 663         new_root = btrfs_get_fs_root(fs_info, &key, true);
 664         if (IS_ERR(new_root)) {
 665                 ret = PTR_ERR(new_root);
 666                 btrfs_abort_transaction(trans, ret);
 667                 goto fail;
 668         }
 669
 670         btrfs_record_root_in_trans(trans, new_root);
 671
 672         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 673         btrfs_put_root(new_root);
 674         if (ret) {
 675                 /* We potentially lose an unused inode item here */
 676                 btrfs_abort_transaction(trans, ret);
 677                 goto fail;
 678         }
 679
 680         mutex_lock(&new_root->objectid_mutex);
 681         new_root->highest_objectid = new_dirid;
 682         mutex_unlock(&new_root->objectid_mutex);
 683
 684         /*
 685          * insert the directory item
 686          */
 687         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 688         if (ret) {
 689                 btrfs_abort_transaction(trans, ret);
 690                 goto fail;
 691         }
 692
 693         ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
 694                                     BTRFS_FT_DIR, index);
 695         if (ret) {
 696                 btrfs_abort_transaction(trans, ret);
 697                 goto fail;
 698         }
 699
 700         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 701         ret = btrfs_update_inode(trans, root, dir);
 702         if (ret) {
 703                 btrfs_abort_transaction(trans, ret);
 704                 goto fail;
 705         }
 706
 707         ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
 708                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 709         if (ret) {
 710                 btrfs_abort_transaction(trans, ret);
 711                 goto fail;
 712         }
 713
 714         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 715                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 716         if (ret)
 717                 btrfs_abort_transaction(trans, ret);
 718
 719 fail:
 720         kfree(root_item);
 721         trans->block_rsv = NULL;
 722         trans->bytes_reserved = 0;
 723         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 724
 725         err = btrfs_commit_transaction(trans);
 726         if (err && !ret)
 727                 ret = err;
 728
 729         if (!ret) {
 730                 inode = btrfs_lookup_dentry(dir, dentry);
 731                 if (IS_ERR(inode))
 732                         return PTR_ERR(inode);
 733                 d_instantiate(dentry, inode);
 734         }
 735         return ret;
 736
 737 fail_free:
 738         kfree(root_item);
 739         return ret;
 740 }
 741
 742 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 743                            struct dentry *dentry, bool readonly,
 744                            struct btrfs_qgroup_inherit *inherit)
 745 {
 746         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 747         struct inode *inode;
 748         struct btrfs_pending_snapshot *pending_snapshot;
 749         struct btrfs_trans_handle *trans;
 750         int ret;
 751         bool snapshot_force_cow = false;
 752
 753         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 754                 return -EINVAL;
 755
 756         if (atomic_read(&root->nr_swapfiles)) {
 757                 btrfs_warn(fs_info,
 758                            "cannot snapshot subvolume with active swapfile");
 759                 return -ETXTBSY;
 760         }
 761
 762         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 763         if (!pending_snapshot)
 764                 return -ENOMEM;
 765
 766         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 767                         GFP_KERNEL);
 768         pending_snapshot->path = btrfs_alloc_path();
 769         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 770                 ret = -ENOMEM;
 771                 goto free_pending;
 772         }
 773
 774         /*
 775          * Force new buffered writes to reserve space even when NOCOW is
 776          * possible. This is to avoid later writeback (running dealloc) to
 777          * fallback to COW mode and unexpectedly fail with ENOSPC.
 778          */
 779         btrfs_drew_read_lock(&root->snapshot_lock);
 780
 781         ret = btrfs_start_delalloc_snapshot(root);
 782         if (ret)
 783                 goto dec_and_free;
 784
 785         /*
 786          * All previous writes have started writeback in NOCOW mode, so now
 787          * we force future writes to fallback to COW mode during snapshot
 788          * creation.
 789          */
 790         atomic_inc(&root->snapshot_force_cow);
 791         snapshot_force_cow = true;
 792
 793         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 794
 795         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 796                              BTRFS_BLOCK_RSV_TEMP);
 797         /*
 798          * 1 - parent dir inode
 799          * 2 - dir entries
 800          * 1 - root item
 801          * 2 - root ref/backref
 802          * 1 - root of snapshot
 803          * 1 - UUID item
 804          */
 805         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 806                                         &pending_snapshot->block_rsv, 8,
 807                                         false);
 808         if (ret)
 809                 goto dec_and_free;
 810
 811         pending_snapshot->dentry = dentry;
 812         pending_snapshot->root = root;
 813         pending_snapshot->readonly = readonly;
 814         pending_snapshot->dir = dir;
 815         pending_snapshot->inherit = inherit;
 816
 817         trans = btrfs_start_transaction(root, 0);
 818         if (IS_ERR(trans)) {
 819                 ret = PTR_ERR(trans);
 820                 goto fail;
 821         }
 822
 823         spin_lock(&fs_info->trans_lock);
 824         list_add(&pending_snapshot->list,
 825                  &trans->transaction->pending_snapshots);
 826         spin_unlock(&fs_info->trans_lock);
 827
 828         ret = btrfs_commit_transaction(trans);
 829         if (ret)
 830                 goto fail;
 831
 832         ret = pending_snapshot->error;
 833         if (ret)
 834                 goto fail;
 835
 836         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 837         if (ret)
 838                 goto fail;
 839
 840         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 841         if (IS_ERR(inode)) {
 842                 ret = PTR_ERR(inode);
 843                 goto fail;
 844         }
 845
 846         d_instantiate(dentry, inode);
 847         ret = 0;
 848 fail:
 849         btrfs_put_root(pending_snapshot->snap);
 850         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 851 dec_and_free:
 852         if (snapshot_force_cow)
 853                 atomic_dec(&root->snapshot_force_cow);
 854         btrfs_drew_read_unlock(&root->snapshot_lock);
 855
 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                                    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, readonly, inherit);
 972         else
 973                 error = create_subvol(dir, dentry, name, namelen, inherit);
 974
 975         if (!error)
 976                 fsnotify_mkdir(dir, dentry);
 977 out_up_read:
 978         up_read(&fs_info->subvol_sem);
 979 out_dput:
 980         dput(dentry);
 981 out_unlock:
 982         inode_unlock(dir);
 983         return error;
 984 }
 985
 986 /*
 987  * When we're defragging a range, we don't want to kick it off again
 988  * if it is really just waiting for delalloc to send it down.
 989  * If we find a nice big extent or delalloc range for the bytes in the
 990  * file you want to defrag, we return 0 to let you know to skip this
 991  * part of the file
 992  */
 993 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 994 {
 995         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 996         struct extent_map *em = NULL;
 997         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 998         u64 end;
 999
1000         read_lock(&em_tree->lock);
1001         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1002         read_unlock(&em_tree->lock);
1003
1004         if (em) {
1005                 end = extent_map_end(em);
1006                 free_extent_map(em);
1007                 if (end - offset > thresh)
1008                         return 0;
1009         }
1010         /* if we already have a nice delalloc here, just stop */
1011         thresh /= 2;
1012         end = count_range_bits(io_tree, &offset, offset + thresh,
1013                                thresh, EXTENT_DELALLOC, 1);
1014         if (end >= thresh)
1015                 return 0;
1016         return 1;
1017 }
1018
1019 /*
1020  * helper function to walk through a file and find extents
1021  * newer than a specific transid, and smaller than thresh.
1022  *
1023  * This is used by the defragging code to find new and small
1024  * extents
1025  */
1026 static int find_new_extents(struct btrfs_root *root,
1027                             struct inode *inode, u64 newer_than,
1028                             u64 *off, u32 thresh)
1029 {
1030         struct btrfs_path *path;
1031         struct btrfs_key min_key;
1032         struct extent_buffer *leaf;
1033         struct btrfs_file_extent_item *extent;
1034         int type;
1035         int ret;
1036         u64 ino = btrfs_ino(BTRFS_I(inode));
1037
1038         path = btrfs_alloc_path();
1039         if (!path)
1040                 return -ENOMEM;
1041
1042         min_key.objectid = ino;
1043         min_key.type = BTRFS_EXTENT_DATA_KEY;
1044         min_key.offset = *off;
1045
1046         while (1) {
1047                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
1048                 if (ret != 0)
1049                         goto none;
1050 process_slot:
1051                 if (min_key.objectid != ino)
1052                         goto none;
1053                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1054                         goto none;
1055
1056                 leaf = path->nodes[0];
1057                 extent = btrfs_item_ptr(leaf, path->slots[0],
1058                                         struct btrfs_file_extent_item);
1059
1060                 type = btrfs_file_extent_type(leaf, extent);
1061                 if (type == BTRFS_FILE_EXTENT_REG &&
1062                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1063                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
1064                         *off = min_key.offset;
1065                         btrfs_free_path(path);
1066                         return 0;
1067                 }
1068
1069                 path->slots[0]++;
1070                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
1071                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1072                         goto process_slot;
1073                 }
1074
1075                 if (min_key.offset == (u64)-1)
1076                         goto none;
1077
1078                 min_key.offset++;
1079                 btrfs_release_path(path);
1080         }
1081 none:
1082         btrfs_free_path(path);
1083         return -ENOENT;
1084 }
1085
1086 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1087 {
1088         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1089         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1090         struct extent_map *em;
1091         u64 len = PAGE_SIZE;
1092
1093         /*
1094          * hopefully we have this extent in the tree already, try without
1095          * the full extent lock
1096          */
1097         read_lock(&em_tree->lock);
1098         em = lookup_extent_mapping(em_tree, start, len);
1099         read_unlock(&em_tree->lock);
1100
1101         if (!em) {
1102                 struct extent_state *cached = NULL;
1103                 u64 end = start + len - 1;
1104
1105                 /* get the big lock and read metadata off disk */
1106                 lock_extent_bits(io_tree, start, end, &cached);
1107                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
1108                 unlock_extent_cached(io_tree, start, end, &cached);
1109
1110                 if (IS_ERR(em))
1111                         return NULL;
1112         }
1113
1114         return em;
1115 }
1116
1117 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1118 {
1119         struct extent_map *next;
1120         bool ret = true;
1121
1122         /* this is the last extent */
1123         if (em->start + em->len >= i_size_read(inode))
1124                 return false;
1125
1126         next = defrag_lookup_extent(inode, em->start + em->len);
1127         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1128                 ret = false;
1129         else if ((em->block_start + em->block_len == next->block_start) &&
1130                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1131                 ret = false;
1132
1133         free_extent_map(next);
1134         return ret;
1135 }
1136
1137 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1138                                u64 *last_len, u64 *skip, u64 *defrag_end,
1139                                int compress)
1140 {
1141         struct extent_map *em;
1142         int ret = 1;
1143         bool next_mergeable = true;
1144         bool prev_mergeable = true;
1145
1146         /*
1147          * make sure that once we start defragging an extent, we keep on
1148          * defragging it
1149          */
1150         if (start < *defrag_end)
1151                 return 1;
1152
1153         *skip = 0;
1154
1155         em = defrag_lookup_extent(inode, start);
1156         if (!em)
1157                 return 0;
1158
1159         /* this will cover holes, and inline extents */
1160         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1161                 ret = 0;
1162                 goto out;
1163         }
1164
1165         if (!*defrag_end)
1166                 prev_mergeable = false;
1167
1168         next_mergeable = defrag_check_next_extent(inode, em);
1169         /*
1170          * we hit a real extent, if it is big or the next extent is not a
1171          * real extent, don't bother defragging it
1172          */
1173         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1174             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1175                 ret = 0;
1176 out:
1177         /*
1178          * last_len ends up being a counter of how many bytes we've defragged.
1179          * every time we choose not to defrag an extent, we reset *last_len
1180          * so that the next tiny extent will force a defrag.
1181          *
1182          * The end result of this is that tiny extents before a single big
1183          * extent will force at least part of that big extent to be defragged.
1184          */
1185         if (ret) {
1186                 *defrag_end = extent_map_end(em);
1187         } else {
1188                 *last_len = 0;
1189                 *skip = extent_map_end(em);
1190                 *defrag_end = 0;
1191         }
1192
1193         free_extent_map(em);
1194         return ret;
1195 }
1196
1197 /*
1198  * it doesn't do much good to defrag one or two pages
1199  * at a time.  This pulls in a nice chunk of pages
1200  * to COW and defrag.
1201  *
1202  * It also makes sure the delalloc code has enough
1203  * dirty data to avoid making new small extents as part
1204  * of the defrag
1205  *
1206  * It's a good idea to start RA on this range
1207  * before calling this.
1208  */
1209 static int cluster_pages_for_defrag(struct inode *inode,
1210                                     struct page **pages,
1211                                     unsigned long start_index,
1212                                     unsigned long num_pages)
1213 {
1214         unsigned long file_end;
1215         u64 isize = i_size_read(inode);
1216         u64 page_start;
1217         u64 page_end;
1218         u64 page_cnt;
1219         int ret;
1220         int i;
1221         int i_done;
1222         struct btrfs_ordered_extent *ordered;
1223         struct extent_state *cached_state = NULL;
1224         struct extent_io_tree *tree;
1225         struct extent_changeset *data_reserved = NULL;
1226         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1227
1228         file_end = (isize - 1) >> PAGE_SHIFT;
1229         if (!isize || start_index > file_end)
1230                 return 0;
1231
1232         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1233
1234         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1235                         start_index << PAGE_SHIFT,
1236                         page_cnt << PAGE_SHIFT);
1237         if (ret)
1238                 return ret;
1239         i_done = 0;
1240         tree = &BTRFS_I(inode)->io_tree;
1241
1242         /* step one, lock all the pages */
1243         for (i = 0; i < page_cnt; i++) {
1244                 struct page *page;
1245 again:
1246                 page = find_or_create_page(inode->i_mapping,
1247                                            start_index + i, mask);
1248                 if (!page)
1249                         break;
1250
1251                 page_start = page_offset(page);
1252                 page_end = page_start + PAGE_SIZE - 1;
1253                 while (1) {
1254                         lock_extent_bits(tree, page_start, page_end,
1255                                          &cached_state);
1256                         ordered = btrfs_lookup_ordered_extent(inode,
1257                                                               page_start);
1258                         unlock_extent_cached(tree, page_start, page_end,
1259                                              &cached_state);
1260                         if (!ordered)
1261                                 break;
1262
1263                         unlock_page(page);
1264                         btrfs_start_ordered_extent(inode, ordered, 1);
1265                         btrfs_put_ordered_extent(ordered);
1266                         lock_page(page);
1267                         /*
1268                          * we unlocked the page above, so we need check if
1269                          * it was released or not.
1270                          */
1271                         if (page->mapping != inode->i_mapping) {
1272                                 unlock_page(page);
1273                                 put_page(page);
1274                                 goto again;
1275                         }
1276                 }
1277
1278                 if (!PageUptodate(page)) {
1279                         btrfs_readpage(NULL, page);
1280                         lock_page(page);
1281                         if (!PageUptodate(page)) {
1282                                 unlock_page(page);
1283                                 put_page(page);
1284                                 ret = -EIO;
1285                                 break;
1286                         }
1287                 }
1288
1289                 if (page->mapping != inode->i_mapping) {
1290                         unlock_page(page);
1291                         put_page(page);
1292                         goto again;
1293                 }
1294
1295                 pages[i] = page;
1296                 i_done++;
1297         }
1298         if (!i_done || ret)
1299                 goto out;
1300
1301         if (!(inode->i_sb->s_flags & SB_ACTIVE))
1302                 goto out;
1303
1304         /*
1305          * so now we have a nice long stream of locked
1306          * and up to date pages, lets wait on them
1307          */
1308         for (i = 0; i < i_done; i++)
1309                 wait_on_page_writeback(pages[i]);
1310
1311         page_start = page_offset(pages[0]);
1312         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1313
1314         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1315                          page_start, page_end - 1, &cached_state);
1316         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1317                           page_end - 1, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
1318                           EXTENT_DEFRAG, 0, 0, &cached_state);
1319
1320         if (i_done != page_cnt) {
1321                 spin_lock(&BTRFS_I(inode)->lock);
1322                 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1323                 spin_unlock(&BTRFS_I(inode)->lock);
1324                 btrfs_delalloc_release_space(inode, data_reserved,
1325                                 start_index << PAGE_SHIFT,
1326                                 (page_cnt - i_done) << PAGE_SHIFT, true);
1327         }
1328
1329
1330         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1331                           &cached_state);
1332
1333         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1334                              page_start, page_end - 1, &cached_state);
1335
1336         for (i = 0; i < i_done; i++) {
1337                 clear_page_dirty_for_io(pages[i]);
1338                 ClearPageChecked(pages[i]);
1339                 set_page_extent_mapped(pages[i]);
1340                 set_page_dirty(pages[i]);
1341                 unlock_page(pages[i]);
1342                 put_page(pages[i]);
1343         }
1344         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
1345         extent_changeset_free(data_reserved);
1346         return i_done;
1347 out:
1348         for (i = 0; i < i_done; i++) {
1349                 unlock_page(pages[i]);
1350                 put_page(pages[i]);
1351         }
1352         btrfs_delalloc_release_space(inode, data_reserved,
1353                         start_index << PAGE_SHIFT,
1354                         page_cnt << PAGE_SHIFT, true);
1355         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
1356         extent_changeset_free(data_reserved);
1357         return ret;
1358
1359 }
1360
1361 int btrfs_defrag_file(struct inode *inode, struct file *file,
1362                       struct btrfs_ioctl_defrag_range_args *range,
1363                       u64 newer_than, unsigned long max_to_defrag)
1364 {
1365         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1366         struct btrfs_root *root = BTRFS_I(inode)->root;
1367         struct file_ra_state *ra = NULL;
1368         unsigned long last_index;
1369         u64 isize = i_size_read(inode);
1370         u64 last_len = 0;
1371         u64 skip = 0;
1372         u64 defrag_end = 0;
1373         u64 newer_off = range->start;
1374         unsigned long i;
1375         unsigned long ra_index = 0;
1376         int ret;
1377         int defrag_count = 0;
1378         int compress_type = BTRFS_COMPRESS_ZLIB;
1379         u32 extent_thresh = range->extent_thresh;
1380         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1381         unsigned long cluster = max_cluster;
1382         u64 new_align = ~((u64)SZ_128K - 1);
1383         struct page **pages = NULL;
1384         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1385
1386         if (isize == 0)
1387                 return 0;
1388
1389         if (range->start >= isize)
1390                 return -EINVAL;
1391
1392         if (do_compress) {
1393                 if (range->compress_type >= BTRFS_NR_COMPRESS_TYPES)
1394                         return -EINVAL;
1395                 if (range->compress_type)
1396                         compress_type = range->compress_type;
1397         }
1398
1399         if (extent_thresh == 0)
1400                 extent_thresh = SZ_256K;
1401
1402         /*
1403          * If we were not given a file, allocate a readahead context. As
1404          * readahead is just an optimization, defrag will work without it so
1405          * we don't error out.
1406          */
1407         if (!file) {
1408                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1409                 if (ra)
1410                         file_ra_state_init(ra, inode->i_mapping);
1411         } else {
1412                 ra = &file->f_ra;
1413         }
1414
1415         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1416         if (!pages) {
1417                 ret = -ENOMEM;
1418                 goto out_ra;
1419         }
1420
1421         /* find the last page to defrag */
1422         if (range->start + range->len > range->start) {
1423                 last_index = min_t(u64, isize - 1,
1424                          range->start + range->len - 1) >> PAGE_SHIFT;
1425         } else {
1426                 last_index = (isize - 1) >> PAGE_SHIFT;
1427         }
1428
1429         if (newer_than) {
1430                 ret = find_new_extents(root, inode, newer_than,
1431                                        &newer_off, SZ_64K);
1432                 if (!ret) {
1433                         range->start = newer_off;
1434                         /*
1435                          * we always align our defrag to help keep
1436                          * the extents in the file evenly spaced
1437                          */
1438                         i = (newer_off & new_align) >> PAGE_SHIFT;
1439                 } else
1440                         goto out_ra;
1441         } else {
1442                 i = range->start >> PAGE_SHIFT;
1443         }
1444         if (!max_to_defrag)
1445                 max_to_defrag = last_index - i + 1;
1446
1447         /*
1448          * make writeback starts from i, so the defrag range can be
1449          * written sequentially.
1450          */
1451         if (i < inode->i_mapping->writeback_index)
1452                 inode->i_mapping->writeback_index = i;
1453
1454         while (i <= last_index && defrag_count < max_to_defrag &&
1455                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1456                 /*
1457                  * make sure we stop running if someone unmounts
1458                  * the FS
1459                  */
1460                 if (!(inode->i_sb->s_flags & SB_ACTIVE))
1461                         break;
1462
1463                 if (btrfs_defrag_cancelled(fs_info)) {
1464                         btrfs_debug(fs_info, "defrag_file cancelled");
1465                         ret = -EAGAIN;
1466                         break;
1467                 }
1468
1469                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1470                                          extent_thresh, &last_len, &skip,
1471                                          &defrag_end, do_compress)){
1472                         unsigned long next;
1473                         /*
1474                          * the should_defrag function tells us how much to skip
1475                          * bump our counter by the suggested amount
1476                          */
1477                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1478                         i = max(i + 1, next);
1479                         continue;
1480                 }
1481
1482                 if (!newer_than) {
1483                         cluster = (PAGE_ALIGN(defrag_end) >>
1484                                    PAGE_SHIFT) - i;
1485                         cluster = min(cluster, max_cluster);
1486                 } else {
1487                         cluster = max_cluster;
1488                 }
1489
1490                 if (i + cluster > ra_index) {
1491                         ra_index = max(i, ra_index);
1492                         if (ra)
1493                                 page_cache_sync_readahead(inode->i_mapping, ra,
1494                                                 file, ra_index, cluster);
1495                         ra_index += cluster;
1496                 }
1497
1498                 inode_lock(inode);
1499                 if (IS_SWAPFILE(inode)) {
1500                         ret = -ETXTBSY;
1501                 } else {
1502                         if (do_compress)
1503                                 BTRFS_I(inode)->defrag_compress = compress_type;
1504                         ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1505                 }
1506                 if (ret < 0) {
1507                         inode_unlock(inode);
1508                         goto out_ra;
1509                 }
1510
1511                 defrag_count += ret;
1512                 balance_dirty_pages_ratelimited(inode->i_mapping);
1513                 inode_unlock(inode);
1514
1515                 if (newer_than) {
1516                         if (newer_off == (u64)-1)
1517                                 break;
1518
1519                         if (ret > 0)
1520                                 i += ret;
1521
1522                         newer_off = max(newer_off + 1,
1523                                         (u64)i << PAGE_SHIFT);
1524
1525                         ret = find_new_extents(root, inode, newer_than,
1526                                                &newer_off, SZ_64K);
1527                         if (!ret) {
1528                                 range->start = newer_off;
1529                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1530                         } else {
1531                                 break;
1532                         }
1533                 } else {
1534                         if (ret > 0) {
1535                                 i += ret;
1536                                 last_len += ret << PAGE_SHIFT;
1537                         } else {
1538                                 i++;
1539                                 last_len = 0;
1540                         }
1541                 }
1542         }
1543
1544         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1545                 filemap_flush(inode->i_mapping);
1546                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1547                              &BTRFS_I(inode)->runtime_flags))
1548                         filemap_flush(inode->i_mapping);
1549         }
1550
1551         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1552                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1553         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1554                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1555         }
1556
1557         ret = defrag_count;
1558
1559 out_ra:
1560         if (do_compress) {
1561                 inode_lock(inode);
1562                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1563                 inode_unlock(inode);
1564         }
1565         if (!file)
1566                 kfree(ra);
1567         kfree(pages);
1568         return ret;
1569 }
1570
1571 static noinline int btrfs_ioctl_resize(struct file *file,
1572                                         void __user *arg)
1573 {
1574         struct inode *inode = file_inode(file);
1575         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1576         u64 new_size;
1577         u64 old_size;
1578         u64 devid = 1;
1579         struct btrfs_root *root = BTRFS_I(inode)->root;
1580         struct btrfs_ioctl_vol_args *vol_args;
1581         struct btrfs_trans_handle *trans;
1582         struct btrfs_device *device = NULL;
1583         char *sizestr;
1584         char *retptr;
1585         char *devstr = NULL;
1586         int ret = 0;
1587         int mod = 0;
1588
1589         if (!capable(CAP_SYS_ADMIN))
1590                 return -EPERM;
1591
1592         ret = mnt_want_write_file(file);
1593         if (ret)
1594                 return ret;
1595
1596         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1597                 mnt_drop_write_file(file);
1598                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1599         }
1600
1601         vol_args = memdup_user(arg, sizeof(*vol_args));
1602         if (IS_ERR(vol_args)) {
1603                 ret = PTR_ERR(vol_args);
1604                 goto out;
1605         }
1606
1607         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1608
1609         sizestr = vol_args->name;
1610         devstr = strchr(sizestr, ':');
1611         if (devstr) {
1612                 sizestr = devstr + 1;
1613                 *devstr = '\0';
1614                 devstr = vol_args->name;
1615                 ret = kstrtoull(devstr, 10, &devid);
1616                 if (ret)
1617                         goto out_free;
1618                 if (!devid) {
1619                         ret = -EINVAL;
1620                         goto out_free;
1621                 }
1622                 btrfs_info(fs_info, "resizing devid %llu", devid);
1623         }
1624
1625         device = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
1626         if (!device) {
1627                 btrfs_info(fs_info, "resizer unable to find device %llu",
1628                            devid);
1629                 ret = -ENODEV;
1630                 goto out_free;
1631         }
1632
1633         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1634                 btrfs_info(fs_info,
1635                            "resizer unable to apply on readonly device %llu",
1636                        devid);
1637                 ret = -EPERM;
1638                 goto out_free;
1639         }
1640
1641         if (!strcmp(sizestr, "max"))
1642                 new_size = device->bdev->bd_inode->i_size;
1643         else {
1644                 if (sizestr[0] == '-') {
1645                         mod = -1;
1646                         sizestr++;
1647                 } else if (sizestr[0] == '+') {
1648                         mod = 1;
1649                         sizestr++;
1650                 }
1651                 new_size = memparse(sizestr, &retptr);
1652                 if (*retptr != '\0' || new_size == 0) {
1653                         ret = -EINVAL;
1654                         goto out_free;
1655                 }
1656         }
1657
1658         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1659                 ret = -EPERM;
1660                 goto out_free;
1661         }
1662
1663         old_size = btrfs_device_get_total_bytes(device);
1664
1665         if (mod < 0) {
1666                 if (new_size > old_size) {
1667                         ret = -EINVAL;
1668                         goto out_free;
1669                 }
1670                 new_size = old_size - new_size;
1671         } else if (mod > 0) {
1672                 if (new_size > ULLONG_MAX - old_size) {
1673                         ret = -ERANGE;
1674                         goto out_free;
1675                 }
1676                 new_size = old_size + new_size;
1677         }
1678
1679         if (new_size < SZ_256M) {
1680                 ret = -EINVAL;
1681                 goto out_free;
1682         }
1683         if (new_size > device->bdev->bd_inode->i_size) {
1684                 ret = -EFBIG;
1685                 goto out_free;
1686         }
1687
1688         new_size = round_down(new_size, fs_info->sectorsize);
1689
1690         if (new_size > old_size) {
1691                 trans = btrfs_start_transaction(root, 0);
1692                 if (IS_ERR(trans)) {
1693                         ret = PTR_ERR(trans);
1694                         goto out_free;
1695                 }
1696                 ret = btrfs_grow_device(trans, device, new_size);
1697                 btrfs_commit_transaction(trans);
1698         } else if (new_size < old_size) {
1699                 ret = btrfs_shrink_device(device, new_size);
1700         } /* equal, nothing need to do */
1701
1702         if (ret == 0 && new_size != old_size)
1703                 btrfs_info_in_rcu(fs_info,
1704                         "resize device %s (devid %llu) from %llu to %llu",
1705                         rcu_str_deref(device->name), device->devid,
1706                         old_size, new_size);
1707 out_free:
1708         kfree(vol_args);
1709 out:
1710         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1711         mnt_drop_write_file(file);
1712         return ret;
1713 }
1714
1715 static noinline int __btrfs_ioctl_snap_create(struct file *file,
1716                                 const char *name, unsigned long fd, int subvol,
1717                                 bool readonly,
1718                                 struct btrfs_qgroup_inherit *inherit)
1719 {
1720         int namelen;
1721         int ret = 0;
1722
1723         if (!S_ISDIR(file_inode(file)->i_mode))
1724                 return -ENOTDIR;
1725
1726         ret = mnt_want_write_file(file);
1727         if (ret)
1728                 goto out;
1729
1730         namelen = strlen(name);
1731         if (strchr(name, '/')) {
1732                 ret = -EINVAL;
1733                 goto out_drop_write;
1734         }
1735
1736         if (name[0] == '.' &&
1737            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1738                 ret = -EEXIST;
1739                 goto out_drop_write;
1740         }
1741
1742         if (subvol) {
1743                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1744                                      NULL, readonly, inherit);
1745         } else {
1746                 struct fd src = fdget(fd);
1747                 struct inode *src_inode;
1748                 if (!src.file) {
1749                         ret = -EINVAL;
1750                         goto out_drop_write;
1751                 }
1752
1753                 src_inode = file_inode(src.file);
1754                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1755                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1756                                    "Snapshot src from another FS");
1757                         ret = -EXDEV;
1758                 } else if (!inode_owner_or_capable(src_inode)) {
1759                         /*
1760                          * Subvolume creation is not restricted, but snapshots
1761                          * are limited to own subvolumes only
1762                          */
1763                         ret = -EPERM;
1764                 } else {
1765                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1766                                              BTRFS_I(src_inode)->root,
1767                                              readonly, inherit);
1768                 }
1769                 fdput(src);
1770         }
1771 out_drop_write:
1772         mnt_drop_write_file(file);
1773 out:
1774         return ret;
1775 }
1776
1777 static noinline int btrfs_ioctl_snap_create(struct file *file,
1778                                             void __user *arg, int subvol)
1779 {
1780         struct btrfs_ioctl_vol_args *vol_args;
1781         int ret;
1782
1783         if (!S_ISDIR(file_inode(file)->i_mode))
1784                 return -ENOTDIR;
1785
1786         vol_args = memdup_user(arg, sizeof(*vol_args));
1787         if (IS_ERR(vol_args))
1788                 return PTR_ERR(vol_args);
1789         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1790
1791         ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd,
1792                                         subvol, 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         bool readonly = false;
1804         struct btrfs_qgroup_inherit *inherit = NULL;
1805
1806         if (!S_ISDIR(file_inode(file)->i_mode))
1807                 return -ENOTDIR;
1808
1809         vol_args = memdup_user(arg, sizeof(*vol_args));
1810         if (IS_ERR(vol_args))
1811                 return PTR_ERR(vol_args);
1812         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1813
1814         if (vol_args->flags & ~BTRFS_SUBVOL_CREATE_ARGS_MASK) {
1815                 ret = -EOPNOTSUPP;
1816                 goto free_args;
1817         }
1818
1819         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1820                 readonly = true;
1821         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1822                 if (vol_args->size > PAGE_SIZE) {
1823                         ret = -EINVAL;
1824                         goto free_args;
1825                 }
1826                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1827                 if (IS_ERR(inherit)) {
1828                         ret = PTR_ERR(inherit);
1829                         goto free_args;
1830                 }
1831         }
1832
1833         ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd,
1834                                         subvol, readonly, inherit);
1835         if (ret)
1836                 goto free_inherit;
1837 free_inherit:
1838         kfree(inherit);
1839 free_args:
1840         kfree(vol_args);
1841         return ret;
1842 }
1843
1844 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1845                                                 void __user *arg)
1846 {
1847         struct inode *inode = file_inode(file);
1848         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1849         struct btrfs_root *root = BTRFS_I(inode)->root;
1850         int ret = 0;
1851         u64 flags = 0;
1852
1853         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1854                 return -EINVAL;
1855
1856         down_read(&fs_info->subvol_sem);
1857         if (btrfs_root_readonly(root))
1858                 flags |= BTRFS_SUBVOL_RDONLY;
1859         up_read(&fs_info->subvol_sem);
1860
1861         if (copy_to_user(arg, &flags, sizeof(flags)))
1862                 ret = -EFAULT;
1863
1864         return ret;
1865 }
1866
1867 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1868                                               void __user *arg)
1869 {
1870         struct inode *inode = file_inode(file);
1871         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1872         struct btrfs_root *root = BTRFS_I(inode)->root;
1873         struct btrfs_trans_handle *trans;
1874         u64 root_flags;
1875         u64 flags;
1876         int ret = 0;
1877
1878         if (!inode_owner_or_capable(inode))
1879                 return -EPERM;
1880
1881         ret = mnt_want_write_file(file);
1882         if (ret)
1883                 goto out;
1884
1885         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1886                 ret = -EINVAL;
1887                 goto out_drop_write;
1888         }
1889
1890         if (copy_from_user(&flags, arg, sizeof(flags))) {
1891                 ret = -EFAULT;
1892                 goto out_drop_write;
1893         }
1894
1895         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1896                 ret = -EOPNOTSUPP;
1897                 goto out_drop_write;
1898         }
1899
1900         down_write(&fs_info->subvol_sem);
1901
1902         /* nothing to do */
1903         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1904                 goto out_drop_sem;
1905
1906         root_flags = btrfs_root_flags(&root->root_item);
1907         if (flags & BTRFS_SUBVOL_RDONLY) {
1908                 btrfs_set_root_flags(&root->root_item,
1909                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1910         } else {
1911                 /*
1912                  * Block RO -> RW transition if this subvolume is involved in
1913                  * send
1914                  */
1915                 spin_lock(&root->root_item_lock);
1916                 if (root->send_in_progress == 0) {
1917                         btrfs_set_root_flags(&root->root_item,
1918                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1919                         spin_unlock(&root->root_item_lock);
1920                 } else {
1921                         spin_unlock(&root->root_item_lock);
1922                         btrfs_warn(fs_info,
1923                                    "Attempt to set subvolume %llu read-write during send",
1924                                    root->root_key.objectid);
1925                         ret = -EPERM;
1926                         goto out_drop_sem;
1927                 }
1928         }
1929
1930         trans = btrfs_start_transaction(root, 1);
1931         if (IS_ERR(trans)) {
1932                 ret = PTR_ERR(trans);
1933                 goto out_reset;
1934         }
1935
1936         ret = btrfs_update_root(trans, fs_info->tree_root,
1937                                 &root->root_key, &root->root_item);
1938         if (ret < 0) {
1939                 btrfs_end_transaction(trans);
1940                 goto out_reset;
1941         }
1942
1943         ret = btrfs_commit_transaction(trans);
1944
1945 out_reset:
1946         if (ret)
1947                 btrfs_set_root_flags(&root->root_item, root_flags);
1948 out_drop_sem:
1949         up_write(&fs_info->subvol_sem);
1950 out_drop_write:
1951         mnt_drop_write_file(file);
1952 out:
1953         return ret;
1954 }
1955
1956 static noinline int key_in_sk(struct btrfs_key *key,
1957                               struct btrfs_ioctl_search_key *sk)
1958 {
1959         struct btrfs_key test;
1960         int ret;
1961
1962         test.objectid = sk->min_objectid;
1963         test.type = sk->min_type;
1964         test.offset = sk->min_offset;
1965
1966         ret = btrfs_comp_cpu_keys(key, &test);
1967         if (ret < 0)
1968                 return 0;
1969
1970         test.objectid = sk->max_objectid;
1971         test.type = sk->max_type;
1972         test.offset = sk->max_offset;
1973
1974         ret = btrfs_comp_cpu_keys(key, &test);
1975         if (ret > 0)
1976                 return 0;
1977         return 1;
1978 }
1979
1980 static noinline int copy_to_sk(struct btrfs_path *path,
1981                                struct btrfs_key *key,
1982                                struct btrfs_ioctl_search_key *sk,
1983                                size_t *buf_size,
1984                                char __user *ubuf,
1985                                unsigned long *sk_offset,
1986                                int *num_found)
1987 {
1988         u64 found_transid;
1989         struct extent_buffer *leaf;
1990         struct btrfs_ioctl_search_header sh;
1991         struct btrfs_key test;
1992         unsigned long item_off;
1993         unsigned long item_len;
1994         int nritems;
1995         int i;
1996         int slot;
1997         int ret = 0;
1998
1999         leaf = path->nodes[0];
2000         slot = path->slots[0];
2001         nritems = btrfs_header_nritems(leaf);
2002
2003         if (btrfs_header_generation(leaf) > sk->max_transid) {
2004                 i = nritems;
2005                 goto advance_key;
2006         }
2007         found_transid = btrfs_header_generation(leaf);
2008
2009         for (i = slot; i < nritems; i++) {
2010                 item_off = btrfs_item_ptr_offset(leaf, i);
2011                 item_len = btrfs_item_size_nr(leaf, i);
2012
2013                 btrfs_item_key_to_cpu(leaf, key, i);
2014                 if (!key_in_sk(key, sk))
2015                         continue;
2016
2017                 if (sizeof(sh) + item_len > *buf_size) {
2018                         if (*num_found) {
2019                                 ret = 1;
2020                                 goto out;
2021                         }
2022
2023                         /*
2024                          * return one empty item back for v1, which does not
2025                          * handle -EOVERFLOW
2026                          */
2027
2028                         *buf_size = sizeof(sh) + item_len;
2029                         item_len = 0;
2030                         ret = -EOVERFLOW;
2031                 }
2032
2033                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2034                         ret = 1;
2035                         goto out;
2036                 }
2037
2038                 sh.objectid = key->objectid;
2039                 sh.offset = key->offset;
2040                 sh.type = key->type;
2041                 sh.len = item_len;
2042                 sh.transid = found_transid;
2043
2044                 /* copy search result header */
2045                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2046                         ret = -EFAULT;
2047                         goto out;
2048                 }
2049
2050                 *sk_offset += sizeof(sh);
2051
2052                 if (item_len) {
2053                         char __user *up = ubuf + *sk_offset;
2054                         /* copy the item */
2055                         if (read_extent_buffer_to_user(leaf, up,
2056                                                        item_off, item_len)) {
2057                                 ret = -EFAULT;
2058                                 goto out;
2059                         }
2060
2061                         *sk_offset += item_len;
2062                 }
2063                 (*num_found)++;
2064
2065                 if (ret) /* -EOVERFLOW from above */
2066                         goto out;
2067
2068                 if (*num_found >= sk->nr_items) {
2069                         ret = 1;
2070                         goto out;
2071                 }
2072         }
2073 advance_key:
2074         ret = 0;
2075         test.objectid = sk->max_objectid;
2076         test.type = sk->max_type;
2077         test.offset = sk->max_offset;
2078         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2079                 ret = 1;
2080         else if (key->offset < (u64)-1)
2081                 key->offset++;
2082         else if (key->type < (u8)-1) {
2083                 key->offset = 0;
2084                 key->type++;
2085         } else if (key->objectid < (u64)-1) {
2086                 key->offset = 0;
2087                 key->type = 0;
2088                 key->objectid++;
2089         } else
2090                 ret = 1;
2091 out:
2092         /*
2093          *  0: all items from this leaf copied, continue with next
2094          *  1: * more items can be copied, but unused buffer is too small
2095          *     * all items were found
2096          *     Either way, it will stops the loop which iterates to the next
2097          *     leaf
2098          *  -EOVERFLOW: item was to large for buffer
2099          *  -EFAULT: could not copy extent buffer back to userspace
2100          */
2101         return ret;
2102 }
2103
2104 static noinline int search_ioctl(struct inode *inode,
2105                                  struct btrfs_ioctl_search_key *sk,
2106                                  size_t *buf_size,
2107                                  char __user *ubuf)
2108 {
2109         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2110         struct btrfs_root *root;
2111         struct btrfs_key key;
2112         struct btrfs_path *path;
2113         int ret;
2114         int num_found = 0;
2115         unsigned long sk_offset = 0;
2116
2117         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2118                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2119                 return -EOVERFLOW;
2120         }
2121
2122         path = btrfs_alloc_path();
2123         if (!path)
2124                 return -ENOMEM;
2125
2126         if (sk->tree_id == 0) {
2127                 /* search the root of the inode that was passed */
2128                 root = btrfs_grab_root(BTRFS_I(inode)->root);
2129         } else {
2130                 key.objectid = sk->tree_id;
2131                 key.type = BTRFS_ROOT_ITEM_KEY;
2132                 key.offset = (u64)-1;
2133                 root = btrfs_get_fs_root(info, &key, true);
2134                 if (IS_ERR(root)) {
2135                         btrfs_free_path(path);
2136                         return PTR_ERR(root);
2137                 }
2138         }
2139
2140         key.objectid = sk->min_objectid;
2141         key.type = sk->min_type;
2142         key.offset = sk->min_offset;
2143
2144         while (1) {
2145                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2146                 if (ret != 0) {
2147                         if (ret > 0)
2148                                 ret = 0;
2149                         goto err;
2150                 }
2151                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2152                                  &sk_offset, &num_found);
2153                 btrfs_release_path(path);
2154                 if (ret)
2155                         break;
2156
2157         }
2158         if (ret > 0)
2159                 ret = 0;
2160 err:
2161         sk->nr_items = num_found;
2162         btrfs_put_root(root);
2163         btrfs_free_path(path);
2164         return ret;
2165 }
2166
2167 static noinline int btrfs_ioctl_tree_search(struct file *file,
2168                                            void __user *argp)
2169 {
2170         struct btrfs_ioctl_search_args __user *uargs;
2171         struct btrfs_ioctl_search_key sk;
2172         struct inode *inode;
2173         int ret;
2174         size_t buf_size;
2175
2176         if (!capable(CAP_SYS_ADMIN))
2177                 return -EPERM;
2178
2179         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2180
2181         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2182                 return -EFAULT;
2183
2184         buf_size = sizeof(uargs->buf);
2185
2186         inode = file_inode(file);
2187         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2188
2189         /*
2190          * In the origin implementation an overflow is handled by returning a
2191          * search header with a len of zero, so reset ret.
2192          */
2193         if (ret == -EOVERFLOW)
2194                 ret = 0;
2195
2196         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2197                 ret = -EFAULT;
2198         return ret;
2199 }
2200
2201 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2202                                                void __user *argp)
2203 {
2204         struct btrfs_ioctl_search_args_v2 __user *uarg;
2205         struct btrfs_ioctl_search_args_v2 args;
2206         struct inode *inode;
2207         int ret;
2208         size_t buf_size;
2209         const size_t buf_limit = SZ_16M;
2210
2211         if (!capable(CAP_SYS_ADMIN))
2212                 return -EPERM;
2213
2214         /* copy search header and buffer size */
2215         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2216         if (copy_from_user(&args, uarg, sizeof(args)))
2217                 return -EFAULT;
2218
2219         buf_size = args.buf_size;
2220
2221         /* limit result size to 16MB */
2222         if (buf_size > buf_limit)
2223                 buf_size = buf_limit;
2224
2225         inode = file_inode(file);
2226         ret = search_ioctl(inode, &args.key, &buf_size,
2227                            (char __user *)(&uarg->buf[0]));
2228         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2229                 ret = -EFAULT;
2230         else if (ret == -EOVERFLOW &&
2231                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2232                 ret = -EFAULT;
2233
2234         return ret;
2235 }
2236
2237 /*
2238  * Search INODE_REFs to identify path name of 'dirid' directory
2239  * in a 'tree_id' tree. and sets path name to 'name'.
2240  */
2241 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2242                                 u64 tree_id, u64 dirid, char *name)
2243 {
2244         struct btrfs_root *root;
2245         struct btrfs_key key;
2246         char *ptr;
2247         int ret = -1;
2248         int slot;
2249         int len;
2250         int total_len = 0;
2251         struct btrfs_inode_ref *iref;
2252         struct extent_buffer *l;
2253         struct btrfs_path *path;
2254
2255         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2256                 name[0]='\0';
2257                 return 0;
2258         }
2259
2260         path = btrfs_alloc_path();
2261         if (!path)
2262                 return -ENOMEM;
2263
2264         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2265
2266         key.objectid = tree_id;
2267         key.type = BTRFS_ROOT_ITEM_KEY;
2268         key.offset = (u64)-1;
2269         root = btrfs_get_fs_root(info, &key, true);
2270         if (IS_ERR(root)) {
2271                 ret = PTR_ERR(root);
2272                 root = NULL;
2273                 goto out;
2274         }
2275
2276         key.objectid = dirid;
2277         key.type = BTRFS_INODE_REF_KEY;
2278         key.offset = (u64)-1;
2279
2280         while (1) {
2281                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2282                 if (ret < 0)
2283                         goto out;
2284                 else if (ret > 0) {
2285                         ret = btrfs_previous_item(root, path, dirid,
2286                                                   BTRFS_INODE_REF_KEY);
2287                         if (ret < 0)
2288                                 goto out;
2289                         else if (ret > 0) {
2290                                 ret = -ENOENT;
2291                                 goto out;
2292                         }
2293                 }
2294
2295                 l = path->nodes[0];
2296                 slot = path->slots[0];
2297                 btrfs_item_key_to_cpu(l, &key, slot);
2298
2299                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2300                 len = btrfs_inode_ref_name_len(l, iref);
2301                 ptr -= len + 1;
2302                 total_len += len + 1;
2303                 if (ptr < name) {
2304                         ret = -ENAMETOOLONG;
2305                         goto out;
2306                 }
2307
2308                 *(ptr + len) = '/';
2309                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2310
2311                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2312                         break;
2313
2314                 btrfs_release_path(path);
2315                 key.objectid = key.offset;
2316                 key.offset = (u64)-1;
2317                 dirid = key.objectid;
2318         }
2319         memmove(name, ptr, total_len);
2320         name[total_len] = '\0';
2321         ret = 0;
2322 out:
2323         btrfs_put_root(root);
2324         btrfs_free_path(path);
2325         return ret;
2326 }
2327
2328 static int btrfs_search_path_in_tree_user(struct inode *inode,
2329                                 struct btrfs_ioctl_ino_lookup_user_args *args)
2330 {
2331         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2332         struct super_block *sb = inode->i_sb;
2333         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2334         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2335         u64 dirid = args->dirid;
2336         unsigned long item_off;
2337         unsigned long item_len;
2338         struct btrfs_inode_ref *iref;
2339         struct btrfs_root_ref *rref;
2340         struct btrfs_root *root = NULL;
2341         struct btrfs_path *path;
2342         struct btrfs_key key, key2;
2343         struct extent_buffer *leaf;
2344         struct inode *temp_inode;
2345         char *ptr;
2346         int slot;
2347         int len;
2348         int total_len = 0;
2349         int ret;
2350
2351         path = btrfs_alloc_path();
2352         if (!path)
2353                 return -ENOMEM;
2354
2355         /*
2356          * If the bottom subvolume does not exist directly under upper_limit,
2357          * construct the path in from the bottom up.
2358          */
2359         if (dirid != upper_limit.objectid) {
2360                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2361
2362                 key.objectid = treeid;
2363                 key.type = BTRFS_ROOT_ITEM_KEY;
2364                 key.offset = (u64)-1;
2365                 root = btrfs_get_fs_root(fs_info, &key, true);
2366                 if (IS_ERR(root)) {
2367                         ret = PTR_ERR(root);
2368                         goto out;
2369                 }
2370
2371                 key.objectid = dirid;
2372                 key.type = BTRFS_INODE_REF_KEY;
2373                 key.offset = (u64)-1;
2374                 while (1) {
2375                         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2376                         if (ret < 0) {
2377                                 goto out_put;
2378                         } else if (ret > 0) {
2379                                 ret = btrfs_previous_item(root, path, dirid,
2380                                                           BTRFS_INODE_REF_KEY);
2381                                 if (ret < 0) {
2382                                         goto out_put;
2383                                 } else if (ret > 0) {
2384                                         ret = -ENOENT;
2385                                         goto out_put;
2386                                 }
2387                         }
2388
2389                         leaf = path->nodes[0];
2390                         slot = path->slots[0];
2391                         btrfs_item_key_to_cpu(leaf, &key, slot);
2392
2393                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2394                         len = btrfs_inode_ref_name_len(leaf, iref);
2395                         ptr -= len + 1;
2396                         total_len += len + 1;
2397                         if (ptr < args->path) {
2398                                 ret = -ENAMETOOLONG;
2399                                 goto out_put;
2400                         }
2401
2402                         *(ptr + len) = '/';
2403                         read_extent_buffer(leaf, ptr,
2404                                         (unsigned long)(iref + 1), len);
2405
2406                         /* Check the read+exec permission of this directory */
2407                         ret = btrfs_previous_item(root, path, dirid,
2408                                                   BTRFS_INODE_ITEM_KEY);
2409                         if (ret < 0) {
2410                                 goto out_put;
2411                         } else if (ret > 0) {
2412                                 ret = -ENOENT;
2413                                 goto out_put;
2414                         }
2415
2416                         leaf = path->nodes[0];
2417                         slot = path->slots[0];
2418                         btrfs_item_key_to_cpu(leaf, &key2, slot);
2419                         if (key2.objectid != dirid) {
2420                                 ret = -ENOENT;
2421                                 goto out_put;
2422                         }
2423
2424                         temp_inode = btrfs_iget(sb, &key2, root);
2425                         if (IS_ERR(temp_inode)) {
2426                                 ret = PTR_ERR(temp_inode);
2427                                 goto out_put;
2428                         }
2429                         ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2430                         iput(temp_inode);
2431                         if (ret) {
2432                                 ret = -EACCES;
2433                                 goto out_put;
2434                         }
2435
2436                         if (key.offset == upper_limit.objectid)
2437                                 break;
2438                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2439                                 ret = -EACCES;
2440                                 goto out_put;
2441                         }
2442
2443                         btrfs_release_path(path);
2444                         key.objectid = key.offset;
2445                         key.offset = (u64)-1;
2446                         dirid = key.objectid;
2447                 }
2448
2449                 memmove(args->path, ptr, total_len);
2450                 args->path[total_len] = '\0';
2451                 btrfs_put_root(root);
2452                 root = NULL;
2453                 btrfs_release_path(path);
2454         }
2455
2456         /* Get the bottom subvolume's name from ROOT_REF */
2457         key.objectid = treeid;
2458         key.type = BTRFS_ROOT_REF_KEY;
2459         key.offset = args->treeid;
2460         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2461         if (ret < 0) {
2462                 goto out;
2463         } else if (ret > 0) {
2464                 ret = -ENOENT;
2465                 goto out;
2466         }
2467
2468         leaf = path->nodes[0];
2469         slot = path->slots[0];
2470         btrfs_item_key_to_cpu(leaf, &key, slot);
2471
2472         item_off = btrfs_item_ptr_offset(leaf, slot);
2473         item_len = btrfs_item_size_nr(leaf, slot);
2474         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2475         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2476         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2477                 ret = -EINVAL;
2478                 goto out;
2479         }
2480
2481         /* Copy subvolume's name */
2482         item_off += sizeof(struct btrfs_root_ref);
2483         item_len -= sizeof(struct btrfs_root_ref);
2484         read_extent_buffer(leaf, args->name, item_off, item_len);
2485         args->name[item_len] = 0;
2486
2487 out_put:
2488         btrfs_put_root(root);
2489 out:
2490         btrfs_free_path(path);
2491         return ret;
2492 }
2493
2494 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2495                                            void __user *argp)
2496 {
2497         struct btrfs_ioctl_ino_lookup_args *args;
2498         struct inode *inode;
2499         int ret = 0;
2500
2501         args = memdup_user(argp, sizeof(*args));
2502         if (IS_ERR(args))
2503                 return PTR_ERR(args);
2504
2505         inode = file_inode(file);
2506
2507         /*
2508          * Unprivileged query to obtain the containing subvolume root id. The
2509          * path is reset so it's consistent with btrfs_search_path_in_tree.
2510          */
2511         if (args->treeid == 0)
2512                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2513
2514         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2515                 args->name[0] = 0;
2516                 goto out;
2517         }
2518
2519         if (!capable(CAP_SYS_ADMIN)) {
2520                 ret = -EPERM;
2521                 goto out;
2522         }
2523
2524         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2525                                         args->treeid, args->objectid,
2526                                         args->name);
2527
2528 out:
2529         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2530                 ret = -EFAULT;
2531
2532         kfree(args);
2533         return ret;
2534 }
2535
2536 /*
2537  * Version of ino_lookup ioctl (unprivileged)
2538  *
2539  * The main differences from ino_lookup ioctl are:
2540  *
2541  *   1. Read + Exec permission will be checked using inode_permission() during
2542  *      path construction. -EACCES will be returned in case of failure.
2543  *   2. Path construction will be stopped at the inode number which corresponds
2544  *      to the fd with which this ioctl is called. If constructed path does not
2545  *      exist under fd's inode, -EACCES will be returned.
2546  *   3. The name of bottom subvolume is also searched and filled.
2547  */
2548 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2549 {
2550         struct btrfs_ioctl_ino_lookup_user_args *args;
2551         struct inode *inode;
2552         int ret;
2553
2554         args = memdup_user(argp, sizeof(*args));
2555         if (IS_ERR(args))
2556                 return PTR_ERR(args);
2557
2558         inode = file_inode(file);
2559
2560         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2561             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2562                 /*
2563                  * The subvolume does not exist under fd with which this is
2564                  * called
2565                  */
2566                 kfree(args);
2567                 return -EACCES;
2568         }
2569
2570         ret = btrfs_search_path_in_tree_user(inode, args);
2571
2572         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2573                 ret = -EFAULT;
2574
2575         kfree(args);
2576         return ret;
2577 }
2578
2579 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2580 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2581 {
2582         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2583         struct btrfs_fs_info *fs_info;
2584         struct btrfs_root *root;
2585         struct btrfs_path *path;
2586         struct btrfs_key key;
2587         struct btrfs_root_item *root_item;
2588         struct btrfs_root_ref *rref;
2589         struct extent_buffer *leaf;
2590         unsigned long item_off;
2591         unsigned long item_len;
2592         struct inode *inode;
2593         int slot;
2594         int ret = 0;
2595
2596         path = btrfs_alloc_path();
2597         if (!path)
2598                 return -ENOMEM;
2599
2600         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2601         if (!subvol_info) {
2602                 btrfs_free_path(path);
2603                 return -ENOMEM;
2604         }
2605
2606         inode = file_inode(file);
2607         fs_info = BTRFS_I(inode)->root->fs_info;
2608
2609         /* Get root_item of inode's subvolume */
2610         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2611         key.type = BTRFS_ROOT_ITEM_KEY;
2612         key.offset = (u64)-1;
2613         root = btrfs_get_fs_root(fs_info, &key, true);
2614         if (IS_ERR(root)) {
2615                 ret = PTR_ERR(root);
2616                 goto out_free;
2617         }
2618         root_item = &root->root_item;
2619
2620         subvol_info->treeid = key.objectid;
2621
2622         subvol_info->generation = btrfs_root_generation(root_item);
2623         subvol_info->flags = btrfs_root_flags(root_item);
2624
2625         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2626         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2627                                                     BTRFS_UUID_SIZE);
2628         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2629                                                     BTRFS_UUID_SIZE);
2630
2631         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2632         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2633         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2634
2635         subvol_info->otransid = btrfs_root_otransid(root_item);
2636         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2637         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2638
2639         subvol_info->stransid = btrfs_root_stransid(root_item);
2640         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2641         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2642
2643         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2644         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2645         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2646
2647         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2648                 /* Search root tree for ROOT_BACKREF of this subvolume */
2649                 key.type = BTRFS_ROOT_BACKREF_KEY;
2650                 key.offset = 0;
2651                 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2652                 if (ret < 0) {
2653                         goto out;
2654                 } else if (path->slots[0] >=
2655                            btrfs_header_nritems(path->nodes[0])) {
2656                         ret = btrfs_next_leaf(fs_info->tree_root, path);
2657                         if (ret < 0) {
2658                                 goto out;
2659                         } else if (ret > 0) {
2660                                 ret = -EUCLEAN;
2661                                 goto out;
2662                         }
2663                 }
2664
2665                 leaf = path->nodes[0];
2666                 slot = path->slots[0];
2667                 btrfs_item_key_to_cpu(leaf, &key, slot);
2668                 if (key.objectid == subvol_info->treeid &&
2669                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2670                         subvol_info->parent_id = key.offset;
2671
2672                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2673                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2674
2675                         item_off = btrfs_item_ptr_offset(leaf, slot)
2676                                         + sizeof(struct btrfs_root_ref);
2677                         item_len = btrfs_item_size_nr(leaf, slot)
2678                                         - sizeof(struct btrfs_root_ref);
2679                         read_extent_buffer(leaf, subvol_info->name,
2680                                            item_off, item_len);
2681                 } else {
2682                         ret = -ENOENT;
2683                         goto out;
2684                 }
2685         }
2686
2687         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2688                 ret = -EFAULT;
2689
2690 out:
2691         btrfs_put_root(root);
2692 out_free:
2693         btrfs_free_path(path);
2694         kzfree(subvol_info);
2695         return ret;
2696 }
2697
2698 /*
2699  * Return ROOT_REF information of the subvolume containing this inode
2700  * except the subvolume name.
2701  */
2702 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2703 {
2704         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2705         struct btrfs_root_ref *rref;
2706         struct btrfs_root *root;
2707         struct btrfs_path *path;
2708         struct btrfs_key key;
2709         struct extent_buffer *leaf;
2710         struct inode *inode;
2711         u64 objectid;
2712         int slot;
2713         int ret;
2714         u8 found;
2715
2716         path = btrfs_alloc_path();
2717         if (!path)
2718                 return -ENOMEM;
2719
2720         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2721         if (IS_ERR(rootrefs)) {
2722                 btrfs_free_path(path);
2723                 return PTR_ERR(rootrefs);
2724         }
2725
2726         inode = file_inode(file);
2727         root = BTRFS_I(inode)->root->fs_info->tree_root;
2728         objectid = BTRFS_I(inode)->root->root_key.objectid;
2729
2730         key.objectid = objectid;
2731         key.type = BTRFS_ROOT_REF_KEY;
2732         key.offset = rootrefs->min_treeid;
2733         found = 0;
2734
2735         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2736         if (ret < 0) {
2737                 goto out;
2738         } else if (path->slots[0] >=
2739                    btrfs_header_nritems(path->nodes[0])) {
2740                 ret = btrfs_next_leaf(root, path);
2741                 if (ret < 0) {
2742                         goto out;
2743                 } else if (ret > 0) {
2744                         ret = -EUCLEAN;
2745                         goto out;
2746                 }
2747         }
2748         while (1) {
2749                 leaf = path->nodes[0];
2750                 slot = path->slots[0];
2751
2752                 btrfs_item_key_to_cpu(leaf, &key, slot);
2753                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2754                         ret = 0;
2755                         goto out;
2756                 }
2757
2758                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2759                         ret = -EOVERFLOW;
2760                         goto out;
2761                 }
2762
2763                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2764                 rootrefs->rootref[found].treeid = key.offset;
2765                 rootrefs->rootref[found].dirid =
2766                                   btrfs_root_ref_dirid(leaf, rref);
2767                 found++;
2768
2769                 ret = btrfs_next_item(root, path);
2770                 if (ret < 0) {
2771                         goto out;
2772                 } else if (ret > 0) {
2773                         ret = -EUCLEAN;
2774                         goto out;
2775                 }
2776         }
2777
2778 out:
2779         if (!ret || ret == -EOVERFLOW) {
2780                 rootrefs->num_items = found;
2781                 /* update min_treeid for next search */
2782                 if (found)
2783                         rootrefs->min_treeid =
2784                                 rootrefs->rootref[found - 1].treeid + 1;
2785                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2786                         ret = -EFAULT;
2787         }
2788
2789         kfree(rootrefs);
2790         btrfs_free_path(path);
2791
2792         return ret;
2793 }
2794
2795 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2796                                              void __user *arg,
2797                                              bool destroy_v2)
2798 {
2799         struct dentry *parent = file->f_path.dentry;
2800         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2801         struct dentry *dentry;
2802         struct inode *dir = d_inode(parent);
2803         struct inode *inode;
2804         struct btrfs_root *root = BTRFS_I(dir)->root;
2805         struct btrfs_root *dest = NULL;
2806         struct btrfs_ioctl_vol_args *vol_args = NULL;
2807         struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
2808         char *subvol_name, *subvol_name_ptr = NULL;
2809         int subvol_namelen;
2810         int err = 0;
2811         bool destroy_parent = false;
2812
2813         if (destroy_v2) {
2814                 vol_args2 = memdup_user(arg, sizeof(*vol_args2));
2815                 if (IS_ERR(vol_args2))
2816                         return PTR_ERR(vol_args2);
2817
2818                 if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
2819                         err = -EOPNOTSUPP;
2820                         goto out;
2821                 }
2822
2823                 /*
2824                  * If SPEC_BY_ID is not set, we are looking for the subvolume by
2825                  * name, same as v1 currently does.
2826                  */
2827                 if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
2828                         vol_args2->name[BTRFS_SUBVOL_NAME_MAX] = 0;
2829                         subvol_name = vol_args2->name;
2830
2831                         err = mnt_want_write_file(file);
2832                         if (err)
2833                                 goto out;
2834                 } else {
2835                         if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
2836                                 err = -EINVAL;
2837                                 goto out;
2838                         }
2839
2840                         err = mnt_want_write_file(file);
2841                         if (err)
2842                                 goto out;
2843
2844                         dentry = btrfs_get_dentry(fs_info->sb,
2845                                         BTRFS_FIRST_FREE_OBJECTID,
2846                                         vol_args2->subvolid, 0, 0);
2847                         if (IS_ERR(dentry)) {
2848                                 err = PTR_ERR(dentry);
2849                                 goto out_drop_write;
2850                         }
2851
2852                         /*
2853                          * Change the default parent since the subvolume being
2854                          * deleted can be outside of the current mount point.
2855                          */
2856                         parent = btrfs_get_parent(dentry);
2857
2858                         /*
2859                          * At this point dentry->d_name can point to '/' if the
2860                          * subvolume we want to destroy is outsite of the
2861                          * current mount point, so we need to release the
2862                          * current dentry and execute the lookup to return a new
2863                          * one with ->d_name pointing to the
2864                          * <mount point>/subvol_name.
2865                          */
2866                         dput(dentry);
2867                         if (IS_ERR(parent)) {
2868                                 err = PTR_ERR(parent);
2869                                 goto out_drop_write;
2870                         }
2871                         dir = d_inode(parent);
2872
2873                         /*
2874                          * If v2 was used with SPEC_BY_ID, a new parent was
2875                          * allocated since the subvolume can be outside of the
2876                          * current mount point. Later on we need to release this
2877                          * new parent dentry.
2878                          */
2879                         destroy_parent = true;
2880
2881                         subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
2882                                                 fs_info, vol_args2->subvolid);
2883                         if (IS_ERR(subvol_name_ptr)) {
2884                                 err = PTR_ERR(subvol_name_ptr);
2885                                 goto free_parent;
2886                         }
2887                         /* subvol_name_ptr is already NULL termined */
2888                         subvol_name = (char *)kbasename(subvol_name_ptr);
2889                 }
2890         } else {
2891                 vol_args = memdup_user(arg, sizeof(*vol_args));
2892                 if (IS_ERR(vol_args))
2893                         return PTR_ERR(vol_args);
2894
2895                 vol_args->name[BTRFS_PATH_NAME_MAX] = 0;
2896                 subvol_name = vol_args->name;
2897
2898                 err = mnt_want_write_file(file);
2899                 if (err)
2900                         goto out;
2901         }
2902
2903         subvol_namelen = strlen(subvol_name);
2904
2905         if (strchr(subvol_name, '/') ||
2906             strncmp(subvol_name, "..", subvol_namelen) == 0) {
2907                 err = -EINVAL;
2908                 goto free_subvol_name;
2909         }
2910
2911         if (!S_ISDIR(dir->i_mode)) {
2912                 err = -ENOTDIR;
2913                 goto free_subvol_name;
2914         }
2915
2916         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2917         if (err == -EINTR)
2918                 goto free_subvol_name;
2919         dentry = lookup_one_len(subvol_name, parent, subvol_namelen);
2920         if (IS_ERR(dentry)) {
2921                 err = PTR_ERR(dentry);
2922                 goto out_unlock_dir;
2923         }
2924
2925         if (d_really_is_negative(dentry)) {
2926                 err = -ENOENT;
2927                 goto out_dput;
2928         }
2929
2930         inode = d_inode(dentry);
2931         dest = BTRFS_I(inode)->root;
2932         if (!capable(CAP_SYS_ADMIN)) {
2933                 /*
2934                  * Regular user.  Only allow this with a special mount
2935                  * option, when the user has write+exec access to the
2936                  * subvol root, and when rmdir(2) would have been
2937                  * allowed.
2938                  *
2939                  * Note that this is _not_ check that the subvol is
2940                  * empty or doesn't contain data that we wouldn't
2941                  * otherwise be able to delete.
2942                  *
2943                  * Users who want to delete empty subvols should try
2944                  * rmdir(2).
2945                  */
2946                 err = -EPERM;
2947                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2948                         goto out_dput;
2949
2950                 /*
2951                  * Do not allow deletion if the parent dir is the same
2952                  * as the dir to be deleted.  That means the ioctl
2953                  * must be called on the dentry referencing the root
2954                  * of the subvol, not a random directory contained
2955                  * within it.
2956                  */
2957                 err = -EINVAL;
2958                 if (root == dest)
2959                         goto out_dput;
2960
2961                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2962                 if (err)
2963                         goto out_dput;
2964         }
2965
2966         /* check if subvolume may be deleted by a user */
2967         err = btrfs_may_delete(dir, dentry, 1);
2968         if (err)
2969                 goto out_dput;
2970
2971         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2972                 err = -EINVAL;
2973                 goto out_dput;
2974         }
2975
2976         inode_lock(inode);
2977         err = btrfs_delete_subvolume(dir, dentry);
2978         inode_unlock(inode);
2979         if (!err) {
2980                 fsnotify_rmdir(dir, dentry);
2981                 d_delete(dentry);
2982         }
2983
2984 out_dput:
2985         dput(dentry);
2986 out_unlock_dir:
2987         inode_unlock(dir);
2988 free_subvol_name:
2989         kfree(subvol_name_ptr);
2990 free_parent:
2991         if (destroy_parent)
2992                 dput(parent);
2993 out_drop_write:
2994         mnt_drop_write_file(file);
2995 out:
2996         kfree(vol_args2);
2997         kfree(vol_args);
2998         return err;
2999 }
3000
3001 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
3002 {
3003         struct inode *inode = file_inode(file);
3004         struct btrfs_root *root = BTRFS_I(inode)->root;
3005         struct btrfs_ioctl_defrag_range_args *range;
3006         int ret;
3007
3008         ret = mnt_want_write_file(file);
3009         if (ret)
3010                 return ret;
3011
3012         if (btrfs_root_readonly(root)) {
3013                 ret = -EROFS;
3014                 goto out;
3015         }
3016
3017         switch (inode->i_mode & S_IFMT) {
3018         case S_IFDIR:
3019                 if (!capable(CAP_SYS_ADMIN)) {
3020                         ret = -EPERM;
3021                         goto out;
3022                 }
3023                 ret = btrfs_defrag_root(root);
3024                 break;
3025         case S_IFREG:
3026                 /*
3027                  * Note that this does not check the file descriptor for write
3028                  * access. This prevents defragmenting executables that are
3029                  * running and allows defrag on files open in read-only mode.
3030                  */
3031                 if (!capable(CAP_SYS_ADMIN) &&
3032                     inode_permission(inode, MAY_WRITE)) {
3033                         ret = -EPERM;
3034                         goto out;
3035                 }
3036
3037                 range = kzalloc(sizeof(*range), GFP_KERNEL);
3038                 if (!range) {
3039                         ret = -ENOMEM;
3040                         goto out;
3041                 }
3042
3043                 if (argp) {
3044                         if (copy_from_user(range, argp,
3045                                            sizeof(*range))) {
3046                                 ret = -EFAULT;
3047                                 kfree(range);
3048                                 goto out;
3049                         }
3050                         /* compression requires us to start the IO */
3051                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
3052                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
3053                                 range->extent_thresh = (u32)-1;
3054                         }
3055                 } else {
3056                         /* the rest are all set to zero by kzalloc */
3057                         range->len = (u64)-1;
3058                 }
3059                 ret = btrfs_defrag_file(file_inode(file), file,
3060                                         range, BTRFS_OLDEST_GENERATION, 0);
3061                 if (ret > 0)
3062                         ret = 0;
3063                 kfree(range);
3064                 break;
3065         default:
3066                 ret = -EINVAL;
3067         }
3068 out:
3069         mnt_drop_write_file(file);
3070         return ret;
3071 }
3072
3073 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
3074 {
3075         struct btrfs_ioctl_vol_args *vol_args;
3076         int ret;
3077
3078         if (!capable(CAP_SYS_ADMIN))
3079                 return -EPERM;
3080
3081         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
3082                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3083
3084         vol_args = memdup_user(arg, sizeof(*vol_args));
3085         if (IS_ERR(vol_args)) {
3086                 ret = PTR_ERR(vol_args);
3087                 goto out;
3088         }
3089
3090         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3091         ret = btrfs_init_new_device(fs_info, vol_args->name);
3092
3093         if (!ret)
3094                 btrfs_info(fs_info, "disk added %s", vol_args->name);
3095
3096         kfree(vol_args);
3097 out:
3098         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3099         return ret;
3100 }
3101
3102 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3103 {
3104         struct inode *inode = file_inode(file);
3105         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3106         struct btrfs_ioctl_vol_args_v2 *vol_args;
3107         int ret;
3108
3109         if (!capable(CAP_SYS_ADMIN))
3110                 return -EPERM;
3111
3112         ret = mnt_want_write_file(file);
3113         if (ret)
3114                 return ret;
3115
3116         vol_args = memdup_user(arg, sizeof(*vol_args));
3117         if (IS_ERR(vol_args)) {
3118                 ret = PTR_ERR(vol_args);
3119                 goto err_drop;
3120         }
3121
3122         if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
3123                 ret = -EOPNOTSUPP;
3124                 goto out;
3125         }
3126
3127         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3128                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3129                 goto out;
3130         }
3131
3132         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3133                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3134         } else {
3135                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3136                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3137         }
3138         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3139
3140         if (!ret) {
3141                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3142                         btrfs_info(fs_info, "device deleted: id %llu",
3143                                         vol_args->devid);
3144                 else
3145                         btrfs_info(fs_info, "device deleted: %s",
3146                                         vol_args->name);
3147         }
3148 out:
3149         kfree(vol_args);
3150 err_drop:
3151         mnt_drop_write_file(file);
3152         return ret;
3153 }
3154
3155 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3156 {
3157         struct inode *inode = file_inode(file);
3158         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3159         struct btrfs_ioctl_vol_args *vol_args;
3160         int ret;
3161
3162         if (!capable(CAP_SYS_ADMIN))
3163                 return -EPERM;
3164
3165         ret = mnt_want_write_file(file);
3166         if (ret)
3167                 return ret;
3168
3169         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3170                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3171                 goto out_drop_write;
3172         }
3173
3174         vol_args = memdup_user(arg, sizeof(*vol_args));
3175         if (IS_ERR(vol_args)) {
3176                 ret = PTR_ERR(vol_args);
3177                 goto out;
3178         }
3179
3180         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3181         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3182
3183         if (!ret)
3184                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3185         kfree(vol_args);
3186 out:
3187         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3188 out_drop_write:
3189         mnt_drop_write_file(file);
3190
3191         return ret;
3192 }
3193
3194 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3195                                 void __user *arg)
3196 {
3197         struct btrfs_ioctl_fs_info_args *fi_args;
3198         struct btrfs_device *device;
3199         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3200         int ret = 0;
3201
3202         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3203         if (!fi_args)
3204                 return -ENOMEM;
3205
3206         rcu_read_lock();
3207         fi_args->num_devices = fs_devices->num_devices;
3208
3209         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3210                 if (device->devid > fi_args->max_id)
3211                         fi_args->max_id = device->devid;
3212         }
3213         rcu_read_unlock();
3214
3215         memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
3216         fi_args->nodesize = fs_info->nodesize;
3217         fi_args->sectorsize = fs_info->sectorsize;
3218         fi_args->clone_alignment = fs_info->sectorsize;
3219
3220         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3221                 ret = -EFAULT;
3222
3223         kfree(fi_args);
3224         return ret;
3225 }
3226
3227 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3228                                  void __user *arg)
3229 {
3230         struct btrfs_ioctl_dev_info_args *di_args;
3231         struct btrfs_device *dev;
3232         int ret = 0;
3233         char *s_uuid = NULL;
3234
3235         di_args = memdup_user(arg, sizeof(*di_args));
3236         if (IS_ERR(di_args))
3237                 return PTR_ERR(di_args);
3238
3239         if (!btrfs_is_empty_uuid(di_args->uuid))
3240                 s_uuid = di_args->uuid;
3241
3242         rcu_read_lock();
3243         dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
3244                                 NULL, true);
3245
3246         if (!dev) {
3247                 ret = -ENODEV;
3248                 goto out;
3249         }
3250
3251         di_args->devid = dev->devid;
3252         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3253         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3254         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3255         if (dev->name) {
3256                 strncpy(di_args->path, rcu_str_deref(dev->name),
3257                                 sizeof(di_args->path) - 1);
3258                 di_args->path[sizeof(di_args->path) - 1] = 0;
3259         } else {
3260                 di_args->path[0] = '\0';
3261         }
3262
3263 out:
3264         rcu_read_unlock();
3265         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3266                 ret = -EFAULT;
3267
3268         kfree(di_args);
3269         return ret;
3270 }
3271
3272 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3273 {
3274         struct inode *inode = file_inode(file);
3275         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3276         struct btrfs_root *root = BTRFS_I(inode)->root;
3277         struct btrfs_root *new_root;
3278         struct btrfs_dir_item *di;
3279         struct btrfs_trans_handle *trans;
3280         struct btrfs_path *path = NULL;
3281         struct btrfs_key location;
3282         struct btrfs_disk_key disk_key;
3283         u64 objectid = 0;
3284         u64 dir_id;
3285         int ret;
3286
3287         if (!capable(CAP_SYS_ADMIN))
3288                 return -EPERM;
3289
3290         ret = mnt_want_write_file(file);
3291         if (ret)
3292                 return ret;
3293
3294         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3295                 ret = -EFAULT;
3296                 goto out;
3297         }
3298
3299         if (!objectid)
3300                 objectid = BTRFS_FS_TREE_OBJECTID;
3301
3302         location.objectid = objectid;
3303         location.type = BTRFS_ROOT_ITEM_KEY;
3304         location.offset = (u64)-1;
3305
3306         new_root = btrfs_get_fs_root(fs_info, &location, true);
3307         if (IS_ERR(new_root)) {
3308                 ret = PTR_ERR(new_root);
3309                 goto out;
3310         }
3311         if (!is_fstree(new_root->root_key.objectid)) {
3312                 ret = -ENOENT;
3313                 goto out_free;
3314         }
3315
3316         path = btrfs_alloc_path();
3317         if (!path) {
3318                 ret = -ENOMEM;
3319                 goto out_free;
3320         }
3321         path->leave_spinning = 1;
3322
3323         trans = btrfs_start_transaction(root, 1);
3324         if (IS_ERR(trans)) {
3325                 ret = PTR_ERR(trans);
3326                 goto out_free;
3327         }
3328
3329         dir_id = btrfs_super_root_dir(fs_info->super_copy);
3330         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
3331                                    dir_id, "default", 7, 1);
3332         if (IS_ERR_OR_NULL(di)) {
3333                 btrfs_release_path(path);
3334                 btrfs_end_transaction(trans);
3335                 btrfs_err(fs_info,
3336                           "Umm, you don't have the default diritem, this isn't going to work");
3337                 ret = -ENOENT;
3338                 goto out_free;
3339         }
3340
3341         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3342         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3343         btrfs_mark_buffer_dirty(path->nodes[0]);
3344         btrfs_release_path(path);
3345
3346         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
3347         btrfs_end_transaction(trans);
3348 out_free:
3349         btrfs_put_root(new_root);
3350         btrfs_free_path(path);
3351 out:
3352         mnt_drop_write_file(file);
3353         return ret;
3354 }
3355
3356 static void get_block_group_info(struct list_head *groups_list,
3357                                  struct btrfs_ioctl_space_info *space)
3358 {
3359         struct btrfs_block_group *block_group;
3360
3361         space->total_bytes = 0;
3362         space->used_bytes = 0;
3363         space->flags = 0;
3364         list_for_each_entry(block_group, groups_list, list) {
3365                 space->flags = block_group->flags;
3366                 space->total_bytes += block_group->length;
3367                 space->used_bytes += block_group->used;
3368         }
3369 }
3370
3371 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
3372                                    void __user *arg)
3373 {
3374         struct btrfs_ioctl_space_args space_args;
3375         struct btrfs_ioctl_space_info space;
3376         struct btrfs_ioctl_space_info *dest;
3377         struct btrfs_ioctl_space_info *dest_orig;
3378         struct btrfs_ioctl_space_info __user *user_dest;
3379         struct btrfs_space_info *info;
3380         static const u64 types[] = {
3381                 BTRFS_BLOCK_GROUP_DATA,
3382                 BTRFS_BLOCK_GROUP_SYSTEM,
3383                 BTRFS_BLOCK_GROUP_METADATA,
3384                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
3385         };
3386         int num_types = 4;
3387         int alloc_size;
3388         int ret = 0;
3389         u64 slot_count = 0;
3390         int i, c;
3391
3392         if (copy_from_user(&space_args,
3393                            (struct btrfs_ioctl_space_args __user *)arg,
3394                            sizeof(space_args)))
3395                 return -EFAULT;
3396
3397         for (i = 0; i < num_types; i++) {
3398                 struct btrfs_space_info *tmp;
3399
3400                 info = NULL;
3401                 rcu_read_lock();
3402                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
3403                                         list) {
3404                         if (tmp->flags == types[i]) {
3405                                 info = tmp;
3406                                 break;
3407                         }
3408                 }
3409                 rcu_read_unlock();
3410
3411                 if (!info)
3412                         continue;
3413
3414                 down_read(&info->groups_sem);
3415                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3416                         if (!list_empty(&info->block_groups[c]))
3417                                 slot_count++;
3418                 }
3419                 up_read(&info->groups_sem);
3420         }
3421
3422         /*
3423          * Global block reserve, exported as a space_info
3424          */
3425         slot_count++;
3426
3427         /* space_slots == 0 means they are asking for a count */
3428         if (space_args.space_slots == 0) {
3429                 space_args.total_spaces = slot_count;
3430                 goto out;
3431         }
3432
3433         slot_count = min_t(u64, space_args.space_slots, slot_count);
3434
3435         alloc_size = sizeof(*dest) * slot_count;
3436
3437         /* we generally have at most 6 or so space infos, one for each raid
3438          * level.  So, a whole page should be more than enough for everyone
3439          */
3440         if (alloc_size > PAGE_SIZE)
3441                 return -ENOMEM;
3442
3443         space_args.total_spaces = 0;
3444         dest = kmalloc(alloc_size, GFP_KERNEL);
3445         if (!dest)
3446                 return -ENOMEM;
3447         dest_orig = dest;
3448
3449         /* now we have a buffer to copy into */
3450         for (i = 0; i < num_types; i++) {
3451                 struct btrfs_space_info *tmp;
3452
3453                 if (!slot_count)
3454                         break;
3455
3456                 info = NULL;
3457                 rcu_read_lock();
3458                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
3459                                         list) {
3460                         if (tmp->flags == types[i]) {
3461                                 info = tmp;
3462                                 break;
3463                         }
3464                 }
3465                 rcu_read_unlock();
3466
3467                 if (!info)
3468                         continue;
3469                 down_read(&info->groups_sem);
3470                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3471                         if (!list_empty(&info->block_groups[c])) {
3472                                 get_block_group_info(&info->block_groups[c],
3473                                                      &space);
3474                                 memcpy(dest, &space, sizeof(space));
3475                                 dest++;
3476                                 space_args.total_spaces++;
3477                                 slot_count--;
3478                         }
3479                         if (!slot_count)
3480                                 break;
3481                 }
3482                 up_read(&info->groups_sem);
3483         }
3484
3485         /*
3486          * Add global block reserve
3487          */
3488         if (slot_count) {
3489                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3490
3491                 spin_lock(&block_rsv->lock);
3492                 space.total_bytes = block_rsv->size;
3493                 space.used_bytes = block_rsv->size - block_rsv->reserved;
3494                 spin_unlock(&block_rsv->lock);
3495                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3496                 memcpy(dest, &space, sizeof(space));
3497                 space_args.total_spaces++;
3498         }
3499
3500         user_dest = (struct btrfs_ioctl_space_info __user *)
3501                 (arg + sizeof(struct btrfs_ioctl_space_args));
3502
3503         if (copy_to_user(user_dest, dest_orig, alloc_size))
3504                 ret = -EFAULT;
3505
3506         kfree(dest_orig);
3507 out:
3508         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3509                 ret = -EFAULT;
3510
3511         return ret;
3512 }
3513
3514 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3515                                             void __user *argp)
3516 {
3517         struct btrfs_trans_handle *trans;
3518         u64 transid;
3519         int ret;
3520
3521         trans = btrfs_attach_transaction_barrier(root);
3522         if (IS_ERR(trans)) {
3523                 if (PTR_ERR(trans) != -ENOENT)
3524                         return PTR_ERR(trans);
3525
3526                 /* No running transaction, don't bother */
3527                 transid = root->fs_info->last_trans_committed;
3528                 goto out;
3529         }
3530         transid = trans->transid;
3531         ret = btrfs_commit_transaction_async(trans, 0);
3532         if (ret) {
3533                 btrfs_end_transaction(trans);
3534                 return ret;
3535         }
3536 out:
3537         if (argp)
3538                 if (copy_to_user(argp, &transid, sizeof(transid)))
3539                         return -EFAULT;
3540         return 0;
3541 }
3542
3543 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
3544                                            void __user *argp)
3545 {
3546         u64 transid;
3547
3548         if (argp) {
3549                 if (copy_from_user(&transid, argp, sizeof(transid)))
3550                         return -EFAULT;
3551         } else {
3552                 transid = 0;  /* current trans */
3553         }
3554         return btrfs_wait_for_commit(fs_info, transid);
3555 }
3556
3557 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3558 {
3559         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
3560         struct btrfs_ioctl_scrub_args *sa;
3561         int ret;
3562
3563         if (!capable(CAP_SYS_ADMIN))
3564                 return -EPERM;
3565
3566         sa = memdup_user(arg, sizeof(*sa));
3567         if (IS_ERR(sa))
3568                 return PTR_ERR(sa);
3569
3570         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3571                 ret = mnt_want_write_file(file);
3572                 if (ret)
3573                         goto out;
3574         }
3575
3576         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
3577                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3578                               0);
3579
3580         /*
3581          * Copy scrub args to user space even if btrfs_scrub_dev() returned an
3582          * error. This is important as it allows user space to know how much
3583          * progress scrub has done. For example, if scrub is canceled we get
3584          * -ECANCELED from btrfs_scrub_dev() and return that error back to user
3585          * space. Later user space can inspect the progress from the structure
3586          * btrfs_ioctl_scrub_args and resume scrub from where it left off
3587          * previously (btrfs-progs does this).
3588          * If we fail to copy the btrfs_ioctl_scrub_args structure to user space
3589          * then return -EFAULT to signal the structure was not copied or it may
3590          * be corrupt and unreliable due to a partial copy.
3591          */
3592         if (copy_to_user(arg, sa, sizeof(*sa)))
3593                 ret = -EFAULT;
3594
3595         if (!(sa->flags & BTRFS_SCRUB_READONLY))
3596                 mnt_drop_write_file(file);
3597 out:
3598         kfree(sa);
3599         return ret;
3600 }
3601
3602 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
3603 {
3604         if (!capable(CAP_SYS_ADMIN))
3605                 return -EPERM;
3606
3607         return btrfs_scrub_cancel(fs_info);
3608 }
3609
3610 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
3611                                        void __user *arg)
3612 {
3613         struct btrfs_ioctl_scrub_args *sa;
3614         int ret;
3615
3616         if (!capable(CAP_SYS_ADMIN))
3617                 return -EPERM;
3618
3619         sa = memdup_user(arg, sizeof(*sa));
3620         if (IS_ERR(sa))
3621                 return PTR_ERR(sa);
3622
3623         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
3624
3625         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3626                 ret = -EFAULT;
3627
3628         kfree(sa);
3629         return ret;
3630 }
3631
3632 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
3633                                       void __user *arg)
3634 {
3635         struct btrfs_ioctl_get_dev_stats *sa;
3636         int ret;
3637
3638         sa = memdup_user(arg, sizeof(*sa));
3639         if (IS_ERR(sa))
3640                 return PTR_ERR(sa);
3641
3642         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3643                 kfree(sa);
3644                 return -EPERM;
3645         }
3646
3647         ret = btrfs_get_dev_stats(fs_info, sa);
3648
3649         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3650                 ret = -EFAULT;
3651
3652         kfree(sa);
3653         return ret;
3654 }
3655
3656 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
3657                                     void __user *arg)
3658 {
3659         struct btrfs_ioctl_dev_replace_args *p;
3660         int ret;
3661
3662         if (!capable(CAP_SYS_ADMIN))
3663                 return -EPERM;
3664
3665         p = memdup_user(arg, sizeof(*p));
3666         if (IS_ERR(p))
3667                 return PTR_ERR(p);
3668
3669         switch (p->cmd) {
3670         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3671                 if (sb_rdonly(fs_info->sb)) {
3672                         ret = -EROFS;
3673                         goto out;
3674                 }
3675                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3676                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3677                 } else {
3678                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
3679                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3680                 }
3681                 break;
3682         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3683                 btrfs_dev_replace_status(fs_info, p);
3684                 ret = 0;
3685                 break;
3686         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3687                 p->result = btrfs_dev_replace_cancel(fs_info);
3688                 ret = 0;
3689                 break;
3690         default:
3691                 ret = -EINVAL;
3692                 break;
3693         }
3694
3695         if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
3696                 ret = -EFAULT;
3697 out:
3698         kfree(p);
3699         return ret;
3700 }
3701
3702 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3703 {
3704         int ret = 0;
3705         int i;
3706         u64 rel_ptr;
3707         int size;
3708         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3709         struct inode_fs_paths *ipath = NULL;
3710         struct btrfs_path *path;
3711
3712         if (!capable(CAP_DAC_READ_SEARCH))
3713                 return -EPERM;
3714
3715         path = btrfs_alloc_path();
3716         if (!path) {
3717                 ret = -ENOMEM;
3718                 goto out;
3719         }
3720
3721         ipa = memdup_user(arg, sizeof(*ipa));
3722         if (IS_ERR(ipa)) {
3723                 ret = PTR_ERR(ipa);
3724                 ipa = NULL;
3725                 goto out;
3726         }
3727
3728         size = min_t(u32, ipa->size, 4096);
3729         ipath = init_ipath(size, root, path);
3730         if (IS_ERR(ipath)) {
3731                 ret = PTR_ERR(ipath);
3732                 ipath = NULL;
3733                 goto out;
3734         }
3735
3736         ret = paths_from_inode(ipa->inum, ipath);
3737         if (ret < 0)
3738                 goto out;
3739
3740         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3741                 rel_ptr = ipath->fspath->val[i] -
3742                           (u64)(unsigned long)ipath->fspath->val;
3743                 ipath->fspath->val[i] = rel_ptr;
3744         }
3745
3746         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
3747                            ipath->fspath, size);
3748         if (ret) {
3749                 ret = -EFAULT;
3750                 goto out;
3751         }
3752
3753 out:
3754         btrfs_free_path(path);
3755         free_ipath(ipath);
3756         kfree(ipa);
3757
3758         return ret;
3759 }
3760
3761 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3762 {
3763         struct btrfs_data_container *inodes = ctx;
3764         const size_t c = 3 * sizeof(u64);
3765
3766         if (inodes->bytes_left >= c) {
3767                 inodes->bytes_left -= c;
3768                 inodes->val[inodes->elem_cnt] = inum;
3769                 inodes->val[inodes->elem_cnt + 1] = offset;
3770                 inodes->val[inodes->elem_cnt + 2] = root;
3771                 inodes->elem_cnt += 3;
3772         } else {
3773                 inodes->bytes_missing += c - inodes->bytes_left;
3774                 inodes->bytes_left = 0;
3775                 inodes->elem_missed += 3;
3776         }
3777
3778         return 0;
3779 }
3780
3781 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
3782                                         void __user *arg, int version)
3783 {
3784         int ret = 0;
3785         int size;
3786         struct btrfs_ioctl_logical_ino_args *loi;
3787         struct btrfs_data_container *inodes = NULL;
3788         struct btrfs_path *path = NULL;
3789         bool ignore_offset;
3790
3791         if (!capable(CAP_SYS_ADMIN))
3792                 return -EPERM;
3793
3794         loi = memdup_user(arg, sizeof(*loi));
3795         if (IS_ERR(loi))
3796                 return PTR_ERR(loi);
3797
3798         if (version == 1) {
3799                 ignore_offset = false;
3800                 size = min_t(u32, loi->size, SZ_64K);
3801         } else {
3802                 /* All reserved bits must be 0 for now */
3803                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
3804                         ret = -EINVAL;
3805                         goto out_loi;
3806                 }
3807                 /* Only accept flags we have defined so far */
3808                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
3809                         ret = -EINVAL;
3810                         goto out_loi;
3811                 }
3812                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
3813                 size = min_t(u32, loi->size, SZ_16M);
3814         }
3815
3816         path = btrfs_alloc_path();
3817         if (!path) {
3818                 ret = -ENOMEM;
3819                 goto out;
3820         }
3821
3822         inodes = init_data_container(size);
3823         if (IS_ERR(inodes)) {
3824                 ret = PTR_ERR(inodes);
3825                 inodes = NULL;
3826                 goto out;
3827         }
3828
3829         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
3830                                           build_ino_list, inodes, ignore_offset);
3831         if (ret == -EINVAL)
3832                 ret = -ENOENT;
3833         if (ret < 0)
3834                 goto out;
3835
3836         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
3837                            size);
3838         if (ret)
3839                 ret = -EFAULT;
3840
3841 out:
3842         btrfs_free_path(path);
3843         kvfree(inodes);
3844 out_loi:
3845         kfree(loi);
3846
3847         return ret;
3848 }
3849
3850 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
3851                                struct btrfs_ioctl_balance_args *bargs)
3852 {
3853         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3854
3855         bargs->flags = bctl->flags;
3856
3857         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
3858                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3859         if (atomic_read(&fs_info->balance_pause_req))
3860                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3861         if (atomic_read(&fs_info->balance_cancel_req))
3862                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3863
3864         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3865         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3866         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3867
3868         spin_lock(&fs_info->balance_lock);
3869         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3870         spin_unlock(&fs_info->balance_lock);
3871 }
3872
3873 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3874 {
3875         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3876         struct btrfs_fs_info *fs_info = root->fs_info;
3877         struct btrfs_ioctl_balance_args *bargs;
3878         struct btrfs_balance_control *bctl;
3879         bool need_unlock; /* for mut. excl. ops lock */
3880         int ret;
3881
3882         if (!capable(CAP_SYS_ADMIN))
3883                 return -EPERM;
3884
3885         ret = mnt_want_write_file(file);
3886         if (ret)
3887                 return ret;
3888
3889 again:
3890         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3891                 mutex_lock(&fs_info->balance_mutex);
3892                 need_unlock = true;
3893                 goto locked;
3894         }
3895
3896         /*
3897          * mut. excl. ops lock is locked.  Three possibilities:
3898          *   (1) some other op is running
3899          *   (2) balance is running
3900          *   (3) balance is paused -- special case (think resume)
3901          */
3902         mutex_lock(&fs_info->balance_mutex);
3903         if (fs_info->balance_ctl) {
3904                 /* this is either (2) or (3) */
3905                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3906                         mutex_unlock(&fs_info->balance_mutex);
3907                         /*
3908                          * Lock released to allow other waiters to continue,
3909                          * we'll reexamine the status again.
3910                          */
3911                         mutex_lock(&fs_info->balance_mutex);
3912
3913                         if (fs_info->balance_ctl &&
3914                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3915                                 /* this is (3) */
3916                                 need_unlock = false;
3917                                 goto locked;
3918                         }
3919
3920                         mutex_unlock(&fs_info->balance_mutex);
3921                         goto again;
3922                 } else {
3923                         /* this is (2) */
3924                         mutex_unlock(&fs_info->balance_mutex);
3925                         ret = -EINPROGRESS;
3926                         goto out;
3927                 }
3928         } else {
3929                 /* this is (1) */
3930                 mutex_unlock(&fs_info->balance_mutex);
3931                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3932                 goto out;
3933         }
3934
3935 locked:
3936         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
3937
3938         if (arg) {
3939                 bargs = memdup_user(arg, sizeof(*bargs));
3940                 if (IS_ERR(bargs)) {
3941                         ret = PTR_ERR(bargs);
3942                         goto out_unlock;
3943                 }
3944
3945                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
3946                         if (!fs_info->balance_ctl) {
3947                                 ret = -ENOTCONN;
3948                                 goto out_bargs;
3949                         }
3950
3951                         bctl = fs_info->balance_ctl;
3952                         spin_lock(&fs_info->balance_lock);
3953                         bctl->flags |= BTRFS_BALANCE_RESUME;
3954                         spin_unlock(&fs_info->balance_lock);
3955
3956                         goto do_balance;
3957                 }
3958         } else {
3959                 bargs = NULL;
3960         }
3961
3962         if (fs_info->balance_ctl) {
3963                 ret = -EINPROGRESS;
3964                 goto out_bargs;
3965         }
3966
3967         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
3968         if (!bctl) {
3969                 ret = -ENOMEM;
3970                 goto out_bargs;
3971         }
3972
3973         if (arg) {
3974                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3975                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3976                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3977
3978                 bctl->flags = bargs->flags;
3979         } else {
3980                 /* balance everything - no filters */
3981                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3982         }
3983
3984         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
3985                 ret = -EINVAL;
3986                 goto out_bctl;
3987         }
3988
3989 do_balance:
3990         /*
3991          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
3992          * btrfs_balance.  bctl is freed in reset_balance_state, or, if
3993          * restriper was paused all the way until unmount, in free_fs_info.
3994          * The flag should be cleared after reset_balance_state.
3995          */
3996         need_unlock = false;
3997
3998         ret = btrfs_balance(fs_info, bctl, bargs);
3999         bctl = NULL;
4000
4001         if ((ret == 0 || ret == -ECANCELED) && arg) {
4002                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4003                         ret = -EFAULT;
4004         }
4005
4006 out_bctl:
4007         kfree(bctl);
4008 out_bargs:
4009         kfree(bargs);
4010 out_unlock:
4011         mutex_unlock(&fs_info->balance_mutex);
4012         if (need_unlock)
4013                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4014 out:
4015         mnt_drop_write_file(file);
4016         return ret;
4017 }
4018
4019 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4020 {
4021         if (!capable(CAP_SYS_ADMIN))
4022                 return -EPERM;
4023
4024         switch (cmd) {
4025         case BTRFS_BALANCE_CTL_PAUSE:
4026                 return btrfs_pause_balance(fs_info);
4027         case BTRFS_BALANCE_CTL_CANCEL:
4028                 return btrfs_cancel_balance(fs_info);
4029         }
4030
4031         return -EINVAL;
4032 }
4033
4034 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4035                                          void __user *arg)
4036 {
4037         struct btrfs_ioctl_balance_args *bargs;
4038         int ret = 0;
4039
4040         if (!capable(CAP_SYS_ADMIN))
4041                 return -EPERM;
4042
4043         mutex_lock(&fs_info->balance_mutex);
4044         if (!fs_info->balance_ctl) {
4045                 ret = -ENOTCONN;
4046                 goto out;
4047         }
4048
4049         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4050         if (!bargs) {
4051                 ret = -ENOMEM;
4052                 goto out;
4053         }
4054
4055         btrfs_update_ioctl_balance_args(fs_info, bargs);
4056
4057         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4058                 ret = -EFAULT;
4059
4060         kfree(bargs);
4061 out:
4062         mutex_unlock(&fs_info->balance_mutex);
4063         return ret;
4064 }
4065
4066 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4067 {
4068         struct inode *inode = file_inode(file);
4069         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4070         struct btrfs_ioctl_quota_ctl_args *sa;
4071         int ret;
4072
4073         if (!capable(CAP_SYS_ADMIN))
4074                 return -EPERM;
4075
4076         ret = mnt_want_write_file(file);
4077         if (ret)
4078                 return ret;
4079
4080         sa = memdup_user(arg, sizeof(*sa));
4081         if (IS_ERR(sa)) {
4082                 ret = PTR_ERR(sa);
4083                 goto drop_write;
4084         }
4085
4086         down_write(&fs_info->subvol_sem);
4087
4088         switch (sa->cmd) {
4089         case BTRFS_QUOTA_CTL_ENABLE:
4090                 ret = btrfs_quota_enable(fs_info);
4091                 break;
4092         case BTRFS_QUOTA_CTL_DISABLE:
4093                 ret = btrfs_quota_disable(fs_info);
4094                 break;
4095         default:
4096                 ret = -EINVAL;
4097                 break;
4098         }
4099
4100         kfree(sa);
4101         up_write(&fs_info->subvol_sem);
4102 drop_write:
4103         mnt_drop_write_file(file);
4104         return ret;
4105 }
4106
4107 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4108 {
4109         struct inode *inode = file_inode(file);
4110         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4111         struct btrfs_root *root = BTRFS_I(inode)->root;
4112         struct btrfs_ioctl_qgroup_assign_args *sa;
4113         struct btrfs_trans_handle *trans;
4114         int ret;
4115         int err;
4116
4117         if (!capable(CAP_SYS_ADMIN))
4118                 return -EPERM;
4119
4120         ret = mnt_want_write_file(file);
4121         if (ret)
4122                 return ret;
4123
4124         sa = memdup_user(arg, sizeof(*sa));
4125         if (IS_ERR(sa)) {
4126                 ret = PTR_ERR(sa);
4127                 goto drop_write;
4128         }
4129
4130         trans = btrfs_join_transaction(root);
4131         if (IS_ERR(trans)) {
4132                 ret = PTR_ERR(trans);
4133                 goto out;
4134         }
4135
4136         if (sa->assign) {
4137                 ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
4138         } else {
4139                 ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
4140         }
4141
4142         /* update qgroup status and info */
4143         err = btrfs_run_qgroups(trans);
4144         if (err < 0)
4145                 btrfs_handle_fs_error(fs_info, err,
4146                                       "failed to update qgroup status and info");
4147         err = btrfs_end_transaction(trans);
4148         if (err && !ret)
4149                 ret = err;
4150
4151 out:
4152         kfree(sa);
4153 drop_write:
4154         mnt_drop_write_file(file);
4155         return ret;
4156 }
4157
4158 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4159 {
4160         struct inode *inode = file_inode(file);
4161         struct btrfs_root *root = BTRFS_I(inode)->root;
4162         struct btrfs_ioctl_qgroup_create_args *sa;
4163         struct btrfs_trans_handle *trans;
4164         int ret;
4165         int err;
4166
4167         if (!capable(CAP_SYS_ADMIN))
4168                 return -EPERM;
4169
4170         ret = mnt_want_write_file(file);
4171         if (ret)
4172                 return ret;
4173
4174         sa = memdup_user(arg, sizeof(*sa));
4175         if (IS_ERR(sa)) {
4176                 ret = PTR_ERR(sa);
4177                 goto drop_write;
4178         }
4179
4180         if (!sa->qgroupid) {
4181                 ret = -EINVAL;
4182                 goto out;
4183         }
4184
4185         trans = btrfs_join_transaction(root);
4186         if (IS_ERR(trans)) {
4187                 ret = PTR_ERR(trans);
4188                 goto out;
4189         }
4190
4191         if (sa->create) {
4192                 ret = btrfs_create_qgroup(trans, sa->qgroupid);
4193         } else {
4194                 ret = btrfs_remove_qgroup(trans, sa->qgroupid);
4195         }
4196
4197         err = btrfs_end_transaction(trans);
4198         if (err && !ret)
4199                 ret = err;
4200
4201 out:
4202         kfree(sa);
4203 drop_write:
4204         mnt_drop_write_file(file);
4205         return ret;
4206 }
4207
4208 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4209 {
4210         struct inode *inode = file_inode(file);
4211         struct btrfs_root *root = BTRFS_I(inode)->root;
4212         struct btrfs_ioctl_qgroup_limit_args *sa;
4213         struct btrfs_trans_handle *trans;
4214         int ret;
4215         int err;
4216         u64 qgroupid;
4217
4218         if (!capable(CAP_SYS_ADMIN))
4219                 return -EPERM;
4220
4221         ret = mnt_want_write_file(file);
4222         if (ret)
4223                 return ret;
4224
4225         sa = memdup_user(arg, sizeof(*sa));
4226         if (IS_ERR(sa)) {
4227                 ret = PTR_ERR(sa);
4228                 goto drop_write;
4229         }
4230
4231         trans = btrfs_join_transaction(root);
4232         if (IS_ERR(trans)) {
4233                 ret = PTR_ERR(trans);
4234                 goto out;
4235         }
4236
4237         qgroupid = sa->qgroupid;
4238         if (!qgroupid) {
4239                 /* take the current subvol as qgroup */
4240                 qgroupid = root->root_key.objectid;
4241         }
4242
4243         ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
4244
4245         err = btrfs_end_transaction(trans);
4246         if (err && !ret)
4247                 ret = err;
4248
4249 out:
4250         kfree(sa);
4251 drop_write:
4252         mnt_drop_write_file(file);
4253         return ret;
4254 }
4255
4256 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4257 {
4258         struct inode *inode = file_inode(file);
4259         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4260         struct btrfs_ioctl_quota_rescan_args *qsa;
4261         int ret;
4262
4263         if (!capable(CAP_SYS_ADMIN))
4264                 return -EPERM;
4265
4266         ret = mnt_want_write_file(file);
4267         if (ret)
4268                 return ret;
4269
4270         qsa = memdup_user(arg, sizeof(*qsa));
4271         if (IS_ERR(qsa)) {
4272                 ret = PTR_ERR(qsa);
4273                 goto drop_write;
4274         }
4275
4276         if (qsa->flags) {
4277                 ret = -EINVAL;
4278                 goto out;
4279         }
4280
4281         ret = btrfs_qgroup_rescan(fs_info);
4282
4283 out:
4284         kfree(qsa);
4285 drop_write:
4286         mnt_drop_write_file(file);
4287         return ret;
4288 }
4289
4290 static long btrfs_ioctl_quota_rescan_status(struct btrfs_fs_info *fs_info,
4291                                                 void __user *arg)
4292 {
4293         struct btrfs_ioctl_quota_rescan_args *qsa;
4294         int ret = 0;
4295
4296         if (!capable(CAP_SYS_ADMIN))
4297                 return -EPERM;
4298
4299         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
4300         if (!qsa)
4301                 return -ENOMEM;
4302
4303         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4304                 qsa->flags = 1;
4305                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
4306         }
4307
4308         if (copy_to_user(arg, qsa, sizeof(*qsa)))
4309                 ret = -EFAULT;
4310
4311         kfree(qsa);
4312         return ret;
4313 }
4314
4315 static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info,
4316                                                 void __user *arg)
4317 {
4318         if (!capable(CAP_SYS_ADMIN))
4319                 return -EPERM;
4320
4321         return btrfs_qgroup_wait_for_completion(fs_info, true);
4322 }
4323
4324 static long _btrfs_ioctl_set_received_subvol(struct file *file,
4325                                             struct btrfs_ioctl_received_subvol_args *sa)
4326 {
4327         struct inode *inode = file_inode(file);
4328         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4329         struct btrfs_root *root = BTRFS_I(inode)->root;
4330         struct btrfs_root_item *root_item = &root->root_item;
4331         struct btrfs_trans_handle *trans;
4332         struct timespec64 ct = current_time(inode);
4333         int ret = 0;
4334         int received_uuid_changed;
4335
4336         if (!inode_owner_or_capable(inode))
4337                 return -EPERM;
4338
4339         ret = mnt_want_write_file(file);
4340         if (ret < 0)
4341                 return ret;
4342
4343         down_write(&fs_info->subvol_sem);
4344
4345         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
4346                 ret = -EINVAL;
4347                 goto out;
4348         }
4349
4350         if (btrfs_root_readonly(root)) {
4351                 ret = -EROFS;
4352                 goto out;
4353         }
4354
4355         /*
4356          * 1 - root item
4357          * 2 - uuid items (received uuid + subvol uuid)
4358          */
4359         trans = btrfs_start_transaction(root, 3);
4360         if (IS_ERR(trans)) {
4361                 ret = PTR_ERR(trans);
4362                 trans = NULL;
4363                 goto out;
4364         }
4365
4366         sa->rtransid = trans->transid;
4367         sa->rtime.sec = ct.tv_sec;
4368         sa->rtime.nsec = ct.tv_nsec;
4369
4370         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4371                                        BTRFS_UUID_SIZE);
4372         if (received_uuid_changed &&
4373             !btrfs_is_empty_uuid(root_item->received_uuid)) {
4374                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
4375                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4376                                           root->root_key.objectid);
4377                 if (ret && ret != -ENOENT) {
4378                         btrfs_abort_transaction(trans, ret);
4379                         btrfs_end_transaction(trans);
4380                         goto out;
4381                 }
4382         }
4383         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4384         btrfs_set_root_stransid(root_item, sa->stransid);
4385         btrfs_set_root_rtransid(root_item, sa->rtransid);
4386         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4387         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4388         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4389         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4390
4391         ret = btrfs_update_root(trans, fs_info->tree_root,
4392                                 &root->root_key, &root->root_item);
4393         if (ret < 0) {
4394                 btrfs_end_transaction(trans);
4395                 goto out;
4396         }
4397         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4398                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
4399                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4400                                           root->root_key.objectid);
4401                 if (ret < 0 && ret != -EEXIST) {
4402                         btrfs_abort_transaction(trans, ret);
4403                         btrfs_end_transaction(trans);
4404                         goto out;
4405                 }
4406         }
4407         ret = btrfs_commit_transaction(trans);
4408 out:
4409         up_write(&fs_info->subvol_sem);
4410         mnt_drop_write_file(file);
4411         return ret;
4412 }
4413
4414 #ifdef CONFIG_64BIT
4415 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4416                                                 void __user *arg)
4417 {
4418         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4419         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4420         int ret = 0;
4421
4422         args32 = memdup_user(arg, sizeof(*args32));
4423         if (IS_ERR(args32))
4424                 return PTR_ERR(args32);
4425
4426         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
4427         if (!args64) {
4428                 ret = -ENOMEM;
4429                 goto out;
4430         }
4431
4432         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4433         args64->stransid = args32->stransid;
4434         args64->rtransid = args32->rtransid;
4435         args64->stime.sec = args32->stime.sec;
4436         args64->stime.nsec = args32->stime.nsec;
4437         args64->rtime.sec = args32->rtime.sec;
4438         args64->rtime.nsec = args32->rtime.nsec;
4439         args64->flags = args32->flags;
4440
4441         ret = _btrfs_ioctl_set_received_subvol(file, args64);
4442         if (ret)
4443                 goto out;
4444
4445         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4446         args32->stransid = args64->stransid;
4447         args32->rtransid = args64->rtransid;
4448         args32->stime.sec = args64->stime.sec;
4449         args32->stime.nsec = args64->stime.nsec;
4450         args32->rtime.sec = args64->rtime.sec;
4451         args32->rtime.nsec = args64->rtime.nsec;
4452         args32->flags = args64->flags;
4453
4454         ret = copy_to_user(arg, args32, sizeof(*args32));
4455         if (ret)
4456                 ret = -EFAULT;
4457
4458 out:
4459         kfree(args32);
4460         kfree(args64);
4461         return ret;
4462 }
4463 #endif
4464
4465 static long btrfs_ioctl_set_received_subvol(struct file *file,
4466                                             void __user *arg)
4467 {
4468         struct btrfs_ioctl_received_subvol_args *sa = NULL;
4469         int ret = 0;
4470
4471         sa = memdup_user(arg, sizeof(*sa));
4472         if (IS_ERR(sa))
4473                 return PTR_ERR(sa);
4474
4475         ret = _btrfs_ioctl_set_received_subvol(file, sa);
4476
4477         if (ret)
4478                 goto out;
4479
4480         ret = copy_to_user(arg, sa, sizeof(*sa));
4481         if (ret)
4482                 ret = -EFAULT;
4483
4484 out:
4485         kfree(sa);
4486         return ret;
4487 }
4488
4489 static int btrfs_ioctl_get_fslabel(struct btrfs_fs_info *fs_info,
4490                                         void __user *arg)
4491 {
4492         size_t len;
4493         int ret;
4494         char label[BTRFS_LABEL_SIZE];
4495
4496         spin_lock(&fs_info->super_lock);
4497         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4498         spin_unlock(&fs_info->super_lock);
4499
4500         len = strnlen(label, BTRFS_LABEL_SIZE);
4501
4502         if (len == BTRFS_LABEL_SIZE) {
4503                 btrfs_warn(fs_info,
4504                            "label is too long, return the first %zu bytes",
4505                            --len);
4506         }
4507
4508         ret = copy_to_user(arg, label, len);
4509
4510         return ret ? -EFAULT : 0;
4511 }
4512
4513 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4514 {
4515         struct inode *inode = file_inode(file);
4516         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4517         struct btrfs_root *root = BTRFS_I(inode)->root;
4518         struct btrfs_super_block *super_block = fs_info->super_copy;
4519         struct btrfs_trans_handle *trans;
4520         char label[BTRFS_LABEL_SIZE];
4521         int ret;
4522
4523         if (!capable(CAP_SYS_ADMIN))
4524                 return -EPERM;
4525
4526         if (copy_from_user(label, arg, sizeof(label)))
4527                 return -EFAULT;
4528
4529         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4530                 btrfs_err(fs_info,
4531                           "unable to set label with more than %d bytes",
4532                           BTRFS_LABEL_SIZE - 1);
4533                 return -EINVAL;
4534         }
4535
4536         ret = mnt_want_write_file(file);
4537         if (ret)
4538                 return ret;
4539
4540         trans = btrfs_start_transaction(root, 0);
4541         if (IS_ERR(trans)) {
4542                 ret = PTR_ERR(trans);
4543                 goto out_unlock;
4544         }
4545
4546         spin_lock(&fs_info->super_lock);
4547         strcpy(super_block->label, label);
4548         spin_unlock(&fs_info->super_lock);
4549         ret = btrfs_commit_transaction(trans);
4550
4551 out_unlock:
4552         mnt_drop_write_file(file);
4553         return ret;
4554 }
4555
4556 #define INIT_FEATURE_FLAGS(suffix) \
4557         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
4558           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
4559           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
4560
4561 int btrfs_ioctl_get_supported_features(void __user *arg)
4562 {
4563         static const struct btrfs_ioctl_feature_flags features[3] = {
4564                 INIT_FEATURE_FLAGS(SUPP),
4565                 INIT_FEATURE_FLAGS(SAFE_SET),
4566                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
4567         };
4568
4569         if (copy_to_user(arg, &features, sizeof(features)))
4570                 return -EFAULT;
4571
4572         return 0;
4573 }
4574
4575 static int btrfs_ioctl_get_features(struct btrfs_fs_info *fs_info,
4576                                         void __user *arg)
4577 {
4578         struct btrfs_super_block *super_block = fs_info->super_copy;
4579         struct btrfs_ioctl_feature_flags features;
4580
4581         features.compat_flags = btrfs_super_compat_flags(super_block);
4582         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
4583         features.incompat_flags = btrfs_super_incompat_flags(super_block);
4584
4585         if (copy_to_user(arg, &features, sizeof(features)))
4586                 return -EFAULT;
4587
4588         return 0;
4589 }
4590
4591 static int check_feature_bits(struct btrfs_fs_info *fs_info,
4592                               enum btrfs_feature_set set,
4593                               u64 change_mask, u64 flags, u64 supported_flags,
4594                               u64 safe_set, u64 safe_clear)
4595 {
4596         const char *type = btrfs_feature_set_name(set);
4597         char *names;
4598         u64 disallowed, unsupported;
4599         u64 set_mask = flags & change_mask;
4600         u64 clear_mask = ~flags & change_mask;
4601
4602         unsupported = set_mask & ~supported_flags;
4603         if (unsupported) {
4604                 names = btrfs_printable_features(set, unsupported);
4605                 if (names) {
4606                         btrfs_warn(fs_info,
4607                                    "this kernel does not support the %s feature bit%s",
4608                                    names, strchr(names, ',') ? "s" : "");
4609                         kfree(names);
4610                 } else
4611                         btrfs_warn(fs_info,
4612                                    "this kernel does not support %s bits 0x%llx",
4613                                    type, unsupported);
4614                 return -EOPNOTSUPP;
4615         }
4616
4617         disallowed = set_mask & ~safe_set;
4618         if (disallowed) {
4619                 names = btrfs_printable_features(set, disallowed);
4620                 if (names) {
4621                         btrfs_warn(fs_info,
4622                                    "can't set the %s feature bit%s while mounted",
4623                                    names, strchr(names, ',') ? "s" : "");
4624                         kfree(names);
4625                 } else
4626                         btrfs_warn(fs_info,
4627                                    "can't set %s bits 0x%llx while mounted",
4628                                    type, disallowed);
4629                 return -EPERM;
4630         }
4631
4632         disallowed = clear_mask & ~safe_clear;
4633         if (disallowed) {
4634                 names = btrfs_printable_features(set, disallowed);
4635                 if (names) {
4636                         btrfs_warn(fs_info,
4637                                    "can't clear the %s feature bit%s while mounted",
4638                                    names, strchr(names, ',') ? "s" : "");
4639                         kfree(names);
4640                 } else
4641                         btrfs_warn(fs_info,
4642                                    "can't clear %s bits 0x%llx while mounted",
4643                                    type, disallowed);
4644                 return -EPERM;
4645         }
4646
4647         return 0;
4648 }
4649
4650 #define check_feature(fs_info, change_mask, flags, mask_base)   \
4651 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
4652                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
4653                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
4654                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
4655
4656 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
4657 {
4658         struct inode *inode = file_inode(file);
4659         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4660         struct btrfs_root *root = BTRFS_I(inode)->root;
4661         struct btrfs_super_block *super_block = fs_info->super_copy;
4662         struct btrfs_ioctl_feature_flags flags[2];
4663         struct btrfs_trans_handle *trans;
4664         u64 newflags;
4665         int ret;
4666
4667         if (!capable(CAP_SYS_ADMIN))
4668                 return -EPERM;
4669
4670         if (copy_from_user(flags, arg, sizeof(flags)))
4671                 return -EFAULT;
4672
4673         /* Nothing to do */
4674         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
4675             !flags[0].incompat_flags)
4676                 return 0;
4677
4678         ret = check_feature(fs_info, flags[0].compat_flags,
4679                             flags[1].compat_flags, COMPAT);
4680         if (ret)
4681                 return ret;
4682
4683         ret = check_feature(fs_info, flags[0].compat_ro_flags,
4684                             flags[1].compat_ro_flags, COMPAT_RO);
4685         if (ret)
4686                 return ret;
4687
4688         ret = check_feature(fs_info, flags[0].incompat_flags,
4689                             flags[1].incompat_flags, INCOMPAT);
4690         if (ret)
4691                 return ret;
4692
4693         ret = mnt_want_write_file(file);
4694         if (ret)
4695                 return ret;
4696
4697         trans = btrfs_start_transaction(root, 0);
4698         if (IS_ERR(trans)) {
4699                 ret = PTR_ERR(trans);
4700                 goto out_drop_write;
4701         }
4702
4703         spin_lock(&fs_info->super_lock);
4704         newflags = btrfs_super_compat_flags(super_block);
4705         newflags |= flags[0].compat_flags & flags[1].compat_flags;
4706         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
4707         btrfs_set_super_compat_flags(super_block, newflags);
4708
4709         newflags = btrfs_super_compat_ro_flags(super_block);
4710         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
4711         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
4712         btrfs_set_super_compat_ro_flags(super_block, newflags);
4713
4714         newflags = btrfs_super_incompat_flags(super_block);
4715         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
4716         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
4717         btrfs_set_super_incompat_flags(super_block, newflags);
4718         spin_unlock(&fs_info->super_lock);
4719
4720         ret = btrfs_commit_transaction(trans);
4721 out_drop_write:
4722         mnt_drop_write_file(file);
4723
4724         return ret;
4725 }
4726
4727 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
4728 {
4729         struct btrfs_ioctl_send_args *arg;
4730         int ret;
4731
4732         if (compat) {
4733 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4734                 struct btrfs_ioctl_send_args_32 args32;
4735
4736                 ret = copy_from_user(&args32, argp, sizeof(args32));
4737                 if (ret)
4738                         return -EFAULT;
4739                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
4740                 if (!arg)
4741                         return -ENOMEM;
4742                 arg->send_fd = args32.send_fd;
4743                 arg->clone_sources_count = args32.clone_sources_count;
4744                 arg->clone_sources = compat_ptr(args32.clone_sources);
4745                 arg->parent_root = args32.parent_root;
4746                 arg->flags = args32.flags;
4747                 memcpy(arg->reserved, args32.reserved,
4748                        sizeof(args32.reserved));
4749 #else
4750                 return -ENOTTY;
4751 #endif
4752         } else {
4753                 arg = memdup_user(argp, sizeof(*arg));
4754                 if (IS_ERR(arg))
4755                         return PTR_ERR(arg);
4756         }
4757         ret = btrfs_ioctl_send(file, arg);
4758         kfree(arg);
4759         return ret;
4760 }
4761
4762 long btrfs_ioctl(struct file *file, unsigned int
4763                 cmd, unsigned long arg)
4764 {
4765         struct inode *inode = file_inode(file);
4766         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4767         struct btrfs_root *root = BTRFS_I(inode)->root;
4768         void __user *argp = (void __user *)arg;
4769
4770         switch (cmd) {
4771         case FS_IOC_GETFLAGS:
4772                 return btrfs_ioctl_getflags(file, argp);
4773         case FS_IOC_SETFLAGS:
4774                 return btrfs_ioctl_setflags(file, argp);
4775         case FS_IOC_GETVERSION:
4776                 return btrfs_ioctl_getversion(file, argp);
4777         case FS_IOC_GETFSLABEL:
4778                 return btrfs_ioctl_get_fslabel(fs_info, argp);
4779         case FS_IOC_SETFSLABEL:
4780                 return btrfs_ioctl_set_fslabel(file, argp);
4781         case FITRIM:
4782                 return btrfs_ioctl_fitrim(fs_info, argp);
4783         case BTRFS_IOC_SNAP_CREATE:
4784                 return btrfs_ioctl_snap_create(file, argp, 0);
4785         case BTRFS_IOC_SNAP_CREATE_V2:
4786                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
4787         case BTRFS_IOC_SUBVOL_CREATE:
4788                 return btrfs_ioctl_snap_create(file, argp, 1);
4789         case BTRFS_IOC_SUBVOL_CREATE_V2:
4790                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
4791         case BTRFS_IOC_SNAP_DESTROY:
4792                 return btrfs_ioctl_snap_destroy(file, argp, false);
4793         case BTRFS_IOC_SNAP_DESTROY_V2:
4794                 return btrfs_ioctl_snap_destroy(file, argp, true);
4795         case BTRFS_IOC_SUBVOL_GETFLAGS:
4796                 return btrfs_ioctl_subvol_getflags(file, argp);
4797         case BTRFS_IOC_SUBVOL_SETFLAGS:
4798                 return btrfs_ioctl_subvol_setflags(file, argp);
4799         case BTRFS_IOC_DEFAULT_SUBVOL:
4800                 return btrfs_ioctl_default_subvol(file, argp);
4801         case BTRFS_IOC_DEFRAG:
4802                 return btrfs_ioctl_defrag(file, NULL);
4803         case BTRFS_IOC_DEFRAG_RANGE:
4804                 return btrfs_ioctl_defrag(file, argp);
4805         case BTRFS_IOC_RESIZE:
4806                 return btrfs_ioctl_resize(file, argp);
4807         case BTRFS_IOC_ADD_DEV:
4808                 return btrfs_ioctl_add_dev(fs_info, argp);
4809         case BTRFS_IOC_RM_DEV:
4810                 return btrfs_ioctl_rm_dev(file, argp);
4811         case BTRFS_IOC_RM_DEV_V2:
4812                 return btrfs_ioctl_rm_dev_v2(file, argp);
4813         case BTRFS_IOC_FS_INFO:
4814                 return btrfs_ioctl_fs_info(fs_info, argp);
4815         case BTRFS_IOC_DEV_INFO:
4816                 return btrfs_ioctl_dev_info(fs_info, argp);
4817         case BTRFS_IOC_BALANCE:
4818                 return btrfs_ioctl_balance(file, NULL);
4819         case BTRFS_IOC_TREE_SEARCH:
4820                 return btrfs_ioctl_tree_search(file, argp);
4821         case BTRFS_IOC_TREE_SEARCH_V2:
4822                 return btrfs_ioctl_tree_search_v2(file, argp);
4823         case BTRFS_IOC_INO_LOOKUP:
4824                 return btrfs_ioctl_ino_lookup(file, argp);
4825         case BTRFS_IOC_INO_PATHS:
4826                 return btrfs_ioctl_ino_to_path(root, argp);
4827         case BTRFS_IOC_LOGICAL_INO:
4828                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
4829         case BTRFS_IOC_LOGICAL_INO_V2:
4830                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
4831         case BTRFS_IOC_SPACE_INFO:
4832                 return btrfs_ioctl_space_info(fs_info, argp);
4833         case BTRFS_IOC_SYNC: {
4834                 int ret;
4835
4836                 ret = btrfs_start_delalloc_roots(fs_info, -1);
4837                 if (ret)
4838                         return ret;
4839                 ret = btrfs_sync_fs(inode->i_sb, 1);
4840                 /*
4841                  * The transaction thread may want to do more work,
4842                  * namely it pokes the cleaner kthread that will start
4843                  * processing uncleaned subvols.
4844                  */
4845                 wake_up_process(fs_info->transaction_kthread);
4846                 return ret;
4847         }
4848         case BTRFS_IOC_START_SYNC:
4849                 return btrfs_ioctl_start_sync(root, argp);
4850         case BTRFS_IOC_WAIT_SYNC:
4851                 return btrfs_ioctl_wait_sync(fs_info, argp);
4852         case BTRFS_IOC_SCRUB:
4853                 return btrfs_ioctl_scrub(file, argp);
4854         case BTRFS_IOC_SCRUB_CANCEL:
4855                 return btrfs_ioctl_scrub_cancel(fs_info);
4856         case BTRFS_IOC_SCRUB_PROGRESS:
4857                 return btrfs_ioctl_scrub_progress(fs_info, argp);
4858         case BTRFS_IOC_BALANCE_V2:
4859                 return btrfs_ioctl_balance(file, argp);
4860         case BTRFS_IOC_BALANCE_CTL:
4861                 return btrfs_ioctl_balance_ctl(fs_info, arg);
4862         case BTRFS_IOC_BALANCE_PROGRESS:
4863                 return btrfs_ioctl_balance_progress(fs_info, argp);
4864         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4865                 return btrfs_ioctl_set_received_subvol(file, argp);
4866 #ifdef CONFIG_64BIT
4867         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
4868                 return btrfs_ioctl_set_received_subvol_32(file, argp);
4869 #endif
4870         case BTRFS_IOC_SEND:
4871                 return _btrfs_ioctl_send(file, argp, false);
4872 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4873         case BTRFS_IOC_SEND_32:
4874                 return _btrfs_ioctl_send(file, argp, true);
4875 #endif
4876         case BTRFS_IOC_GET_DEV_STATS:
4877                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
4878         case BTRFS_IOC_QUOTA_CTL:
4879                 return btrfs_ioctl_quota_ctl(file, argp);
4880         case BTRFS_IOC_QGROUP_ASSIGN:
4881                 return btrfs_ioctl_qgroup_assign(file, argp);
4882         case BTRFS_IOC_QGROUP_CREATE:
4883                 return btrfs_ioctl_qgroup_create(file, argp);
4884         case BTRFS_IOC_QGROUP_LIMIT:
4885                 return btrfs_ioctl_qgroup_limit(file, argp);
4886         case BTRFS_IOC_QUOTA_RESCAN:
4887                 return btrfs_ioctl_quota_rescan(file, argp);
4888         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
4889                 return btrfs_ioctl_quota_rescan_status(fs_info, argp);
4890         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
4891                 return btrfs_ioctl_quota_rescan_wait(fs_info, argp);
4892         case BTRFS_IOC_DEV_REPLACE:
4893                 return btrfs_ioctl_dev_replace(fs_info, argp);
4894         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
4895                 return btrfs_ioctl_get_supported_features(argp);
4896         case BTRFS_IOC_GET_FEATURES:
4897                 return btrfs_ioctl_get_features(fs_info, argp);
4898         case BTRFS_IOC_SET_FEATURES:
4899                 return btrfs_ioctl_set_features(file, argp);
4900         case FS_IOC_FSGETXATTR:
4901                 return btrfs_ioctl_fsgetxattr(file, argp);
4902         case FS_IOC_FSSETXATTR:
4903                 return btrfs_ioctl_fssetxattr(file, argp);
4904         case BTRFS_IOC_GET_SUBVOL_INFO:
4905                 return btrfs_ioctl_get_subvol_info(file, argp);
4906         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
4907                 return btrfs_ioctl_get_subvol_rootref(file, argp);
4908         case BTRFS_IOC_INO_LOOKUP_USER:
4909                 return btrfs_ioctl_ino_lookup_user(file, argp);
4910         }
4911
4912         return -ENOTTY;
4913 }
4914
4915 #ifdef CONFIG_COMPAT
4916 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4917 {
4918         /*
4919          * These all access 32-bit values anyway so no further
4920          * handling is necessary.
4921          */
4922         switch (cmd) {
4923         case FS_IOC32_GETFLAGS:
4924                 cmd = FS_IOC_GETFLAGS;
4925                 break;
4926         case FS_IOC32_SETFLAGS:
4927                 cmd = FS_IOC_SETFLAGS;
4928                 break;
4929         case FS_IOC32_GETVERSION:
4930                 cmd = FS_IOC_GETVERSION;
4931                 break;
4932         }
4933
4934         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
4935 }
4936 #endif