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 <linux/fileattr.h>
  30 #include <linux/fsverity.h>
  31 #include "ctree.h"
  32 #include "disk-io.h"
  33 #include "export.h"
  34 #include "transaction.h"
  35 #include "btrfs_inode.h"
  36 #include "print-tree.h"
  37 #include "volumes.h"
  38 #include "locking.h"
  39 #include "backref.h"
  40 #include "rcu-string.h"
  41 #include "send.h"
  42 #include "dev-replace.h"
  43 #include "props.h"
  44 #include "sysfs.h"
  45 #include "qgroup.h"
  46 #include "tree-log.h"
  47 #include "compression.h"
  48 #include "space-info.h"
  49 #include "delalloc-space.h"
  50 #include "block-group.h"
  51 #include "subpage.h"
  52
  53 #ifdef CONFIG_64BIT
  54 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  55  * structures are incorrect, as the timespec structure from userspace
  56  * is 4 bytes too small. We define these alternatives here to teach
  57  * the kernel about the 32-bit struct packing.
  58  */
  59 struct btrfs_ioctl_timespec_32 {
  60         __u64 sec;
  61         __u32 nsec;
  62 } __attribute__ ((__packed__));
  63
  64 struct btrfs_ioctl_received_subvol_args_32 {
  65         char    uuid[BTRFS_UUID_SIZE];  /* in */
  66         __u64   stransid;               /* in */
  67         __u64   rtransid;               /* out */
  68         struct btrfs_ioctl_timespec_32 stime; /* in */
  69         struct btrfs_ioctl_timespec_32 rtime; /* out */
  70         __u64   flags;                  /* in */
  71         __u64   reserved[16];           /* in */
  72 } __attribute__ ((__packed__));
  73
  74 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  75                                 struct btrfs_ioctl_received_subvol_args_32)
  76 #endif
  77
  78 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  79 struct btrfs_ioctl_send_args_32 {
  80         __s64 send_fd;                  /* in */
  81         __u64 clone_sources_count;      /* in */
  82         compat_uptr_t clone_sources;    /* in */
  83         __u64 parent_root;              /* in */
  84         __u64 flags;                    /* in */
  85         __u32 version;                  /* in */
  86         __u8  reserved[28];             /* in */
  87 } __attribute__ ((__packed__));
  88
  89 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  90                                struct btrfs_ioctl_send_args_32)
  91 #endif
  92
  93 /* Mask out flags that are inappropriate for the given type of inode. */
  94 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
  95                 unsigned int flags)
  96 {
  97         if (S_ISDIR(inode->i_mode))
  98                 return flags;
  99         else if (S_ISREG(inode->i_mode))
 100                 return flags & ~FS_DIRSYNC_FL;
 101         else
 102                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 103 }
 104
 105 /*
 106  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 107  * ioctl.
 108  */
 109 static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode)
 110 {
 111         unsigned int iflags = 0;
 112         u32 flags = binode->flags;
 113         u32 ro_flags = binode->ro_flags;
 114
 115         if (flags & BTRFS_INODE_SYNC)
 116                 iflags |= FS_SYNC_FL;
 117         if (flags & BTRFS_INODE_IMMUTABLE)
 118                 iflags |= FS_IMMUTABLE_FL;
 119         if (flags & BTRFS_INODE_APPEND)
 120                 iflags |= FS_APPEND_FL;
 121         if (flags & BTRFS_INODE_NODUMP)
 122                 iflags |= FS_NODUMP_FL;
 123         if (flags & BTRFS_INODE_NOATIME)
 124                 iflags |= FS_NOATIME_FL;
 125         if (flags & BTRFS_INODE_DIRSYNC)
 126                 iflags |= FS_DIRSYNC_FL;
 127         if (flags & BTRFS_INODE_NODATACOW)
 128                 iflags |= FS_NOCOW_FL;
 129         if (ro_flags & BTRFS_INODE_RO_VERITY)
 130                 iflags |= FS_VERITY_FL;
 131
 132         if (flags & BTRFS_INODE_NOCOMPRESS)
 133                 iflags |= FS_NOCOMP_FL;
 134         else if (flags & BTRFS_INODE_COMPRESS)
 135                 iflags |= FS_COMPR_FL;
 136
 137         return iflags;
 138 }
 139
 140 /*
 141  * Update inode->i_flags based on the btrfs internal flags.
 142  */
 143 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 144 {
 145         struct btrfs_inode *binode = BTRFS_I(inode);
 146         unsigned int new_fl = 0;
 147
 148         if (binode->flags & BTRFS_INODE_SYNC)
 149                 new_fl |= S_SYNC;
 150         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 151                 new_fl |= S_IMMUTABLE;
 152         if (binode->flags & BTRFS_INODE_APPEND)
 153                 new_fl |= S_APPEND;
 154         if (binode->flags & BTRFS_INODE_NOATIME)
 155                 new_fl |= S_NOATIME;
 156         if (binode->flags & BTRFS_INODE_DIRSYNC)
 157                 new_fl |= S_DIRSYNC;
 158         if (binode->ro_flags & BTRFS_INODE_RO_VERITY)
 159                 new_fl |= S_VERITY;
 160
 161         set_mask_bits(&inode->i_flags,
 162                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC |
 163                       S_VERITY, new_fl);
 164 }
 165
 166 /*
 167  * Check if @flags are a supported and valid set of FS_*_FL flags and that
 168  * the old and new flags are not conflicting
 169  */
 170 static int check_fsflags(unsigned int old_flags, unsigned int flags)
 171 {
 172         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 173                       FS_NOATIME_FL | FS_NODUMP_FL | \
 174                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 175                       FS_NOCOMP_FL | FS_COMPR_FL |
 176                       FS_NOCOW_FL))
 177                 return -EOPNOTSUPP;
 178
 179         /* COMPR and NOCOMP on new/old are valid */
 180         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 181                 return -EINVAL;
 182
 183         if ((flags & FS_COMPR_FL) && (flags & FS_NOCOW_FL))
 184                 return -EINVAL;
 185
 186         /* NOCOW and compression options are mutually exclusive */
 187         if ((old_flags & FS_NOCOW_FL) && (flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
 188                 return -EINVAL;
 189         if ((flags & FS_NOCOW_FL) && (old_flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
 190                 return -EINVAL;
 191
 192         return 0;
 193 }
 194
 195 static int check_fsflags_compatible(struct btrfs_fs_info *fs_info,
 196                                     unsigned int flags)
 197 {
 198         if (btrfs_is_zoned(fs_info) && (flags & FS_NOCOW_FL))
 199                 return -EPERM;
 200
 201         return 0;
 202 }
 203
 204 /*
 205  * Set flags/xflags from the internal inode flags. The remaining items of
 206  * fsxattr are zeroed.
 207  */
 208 int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 209 {
 210         struct btrfs_inode *binode = BTRFS_I(d_inode(dentry));
 211
 212         fileattr_fill_flags(fa, btrfs_inode_flags_to_fsflags(binode));
 213         return 0;
 214 }
 215
 216 int btrfs_fileattr_set(struct user_namespace *mnt_userns,
 217                        struct dentry *dentry, struct fileattr *fa)
 218 {
 219         struct inode *inode = d_inode(dentry);
 220         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 221         struct btrfs_inode *binode = BTRFS_I(inode);
 222         struct btrfs_root *root = binode->root;
 223         struct btrfs_trans_handle *trans;
 224         unsigned int fsflags, old_fsflags;
 225         int ret;
 226         const char *comp = NULL;
 227         u32 binode_flags;
 228
 229         if (btrfs_root_readonly(root))
 230                 return -EROFS;
 231
 232         if (fileattr_has_fsx(fa))
 233                 return -EOPNOTSUPP;
 234
 235         fsflags = btrfs_mask_fsflags_for_type(inode, fa->flags);
 236         old_fsflags = btrfs_inode_flags_to_fsflags(binode);
 237         ret = check_fsflags(old_fsflags, fsflags);
 238         if (ret)
 239                 return ret;
 240
 241         ret = check_fsflags_compatible(fs_info, fsflags);
 242         if (ret)
 243                 return ret;
 244
 245         binode_flags = binode->flags;
 246         if (fsflags & FS_SYNC_FL)
 247                 binode_flags |= BTRFS_INODE_SYNC;
 248         else
 249                 binode_flags &= ~BTRFS_INODE_SYNC;
 250         if (fsflags & FS_IMMUTABLE_FL)
 251                 binode_flags |= BTRFS_INODE_IMMUTABLE;
 252         else
 253                 binode_flags &= ~BTRFS_INODE_IMMUTABLE;
 254         if (fsflags & FS_APPEND_FL)
 255                 binode_flags |= BTRFS_INODE_APPEND;
 256         else
 257                 binode_flags &= ~BTRFS_INODE_APPEND;
 258         if (fsflags & FS_NODUMP_FL)
 259                 binode_flags |= BTRFS_INODE_NODUMP;
 260         else
 261                 binode_flags &= ~BTRFS_INODE_NODUMP;
 262         if (fsflags & FS_NOATIME_FL)
 263                 binode_flags |= BTRFS_INODE_NOATIME;
 264         else
 265                 binode_flags &= ~BTRFS_INODE_NOATIME;
 266
 267         /* If coming from FS_IOC_FSSETXATTR then skip unconverted flags */
 268         if (!fa->flags_valid) {
 269                 /* 1 item for the inode */
 270                 trans = btrfs_start_transaction(root, 1);
 271                 if (IS_ERR(trans))
 272                         return PTR_ERR(trans);
 273                 goto update_flags;
 274         }
 275
 276         if (fsflags & FS_DIRSYNC_FL)
 277                 binode_flags |= BTRFS_INODE_DIRSYNC;
 278         else
 279                 binode_flags &= ~BTRFS_INODE_DIRSYNC;
 280         if (fsflags & FS_NOCOW_FL) {
 281                 if (S_ISREG(inode->i_mode)) {
 282                         /*
 283                          * It's safe to turn csums off here, no extents exist.
 284                          * Otherwise we want the flag to reflect the real COW
 285                          * status of the file and will not set it.
 286                          */
 287                         if (inode->i_size == 0)
 288                                 binode_flags |= BTRFS_INODE_NODATACOW |
 289                                                 BTRFS_INODE_NODATASUM;
 290                 } else {
 291                         binode_flags |= BTRFS_INODE_NODATACOW;
 292                 }
 293         } else {
 294                 /*
 295                  * Revert back under same assumptions as above
 296                  */
 297                 if (S_ISREG(inode->i_mode)) {
 298                         if (inode->i_size == 0)
 299                                 binode_flags &= ~(BTRFS_INODE_NODATACOW |
 300                                                   BTRFS_INODE_NODATASUM);
 301                 } else {
 302                         binode_flags &= ~BTRFS_INODE_NODATACOW;
 303                 }
 304         }
 305
 306         /*
 307          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 308          * flag may be changed automatically if compression code won't make
 309          * things smaller.
 310          */
 311         if (fsflags & FS_NOCOMP_FL) {
 312                 binode_flags &= ~BTRFS_INODE_COMPRESS;
 313                 binode_flags |= BTRFS_INODE_NOCOMPRESS;
 314         } else if (fsflags & FS_COMPR_FL) {
 315
 316                 if (IS_SWAPFILE(inode))
 317                         return -ETXTBSY;
 318
 319                 binode_flags |= BTRFS_INODE_COMPRESS;
 320                 binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
 321
 322                 comp = btrfs_compress_type2str(fs_info->compress_type);
 323                 if (!comp || comp[0] == 0)
 324                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 325         } else {
 326                 binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 327         }
 328
 329         /*
 330          * 1 for inode item
 331          * 2 for properties
 332          */
 333         trans = btrfs_start_transaction(root, 3);
 334         if (IS_ERR(trans))
 335                 return PTR_ERR(trans);
 336
 337         if (comp) {
 338                 ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
 339                                      strlen(comp), 0);
 340                 if (ret) {
 341                         btrfs_abort_transaction(trans, ret);
 342                         goto out_end_trans;
 343                 }
 344         } else {
 345                 ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
 346                                      0, 0);
 347                 if (ret && ret != -ENODATA) {
 348                         btrfs_abort_transaction(trans, ret);
 349                         goto out_end_trans;
 350                 }
 351         }
 352
 353 update_flags:
 354         binode->flags = binode_flags;
 355         btrfs_sync_inode_flags_to_i_flags(inode);
 356         inode_inc_iversion(inode);
 357         inode->i_ctime = current_time(inode);
 358         ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
 359
 360  out_end_trans:
 361         btrfs_end_transaction(trans);
 362         return ret;
 363 }
 364
 365 /*
 366  * Start exclusive operation @type, return true on success
 367  */
 368 bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
 369                         enum btrfs_exclusive_operation type)
 370 {
 371         bool ret = false;
 372
 373         spin_lock(&fs_info->super_lock);
 374         if (fs_info->exclusive_operation == BTRFS_EXCLOP_NONE) {
 375                 fs_info->exclusive_operation = type;
 376                 ret = true;
 377         }
 378         spin_unlock(&fs_info->super_lock);
 379
 380         return ret;
 381 }
 382
 383 /*
 384  * Conditionally allow to enter the exclusive operation in case it's compatible
 385  * with the running one.  This must be paired with btrfs_exclop_start_unlock and
 386  * btrfs_exclop_finish.
 387  *
 388  * Compatibility:
 389  * - the same type is already running
 390  * - when trying to add a device and balance has been paused
 391  * - not BTRFS_EXCLOP_NONE - this is intentionally incompatible and the caller
 392  *   must check the condition first that would allow none -> @type
 393  */
 394 bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
 395                                  enum btrfs_exclusive_operation type)
 396 {
 397         spin_lock(&fs_info->super_lock);
 398         if (fs_info->exclusive_operation == type ||
 399             (fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED &&
 400              type == BTRFS_EXCLOP_DEV_ADD))
 401                 return true;
 402
 403         spin_unlock(&fs_info->super_lock);
 404         return false;
 405 }
 406
 407 void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info)
 408 {
 409         spin_unlock(&fs_info->super_lock);
 410 }
 411
 412 void btrfs_exclop_finish(struct btrfs_fs_info *fs_info)
 413 {
 414         spin_lock(&fs_info->super_lock);
 415         WRITE_ONCE(fs_info->exclusive_operation, BTRFS_EXCLOP_NONE);
 416         spin_unlock(&fs_info->super_lock);
 417         sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL, "exclusive_operation");
 418 }
 419
 420 void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
 421                           enum btrfs_exclusive_operation op)
 422 {
 423         switch (op) {
 424         case BTRFS_EXCLOP_BALANCE_PAUSED:
 425                 spin_lock(&fs_info->super_lock);
 426                 ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE ||
 427                        fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD);
 428                 fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE_PAUSED;
 429                 spin_unlock(&fs_info->super_lock);
 430                 break;
 431         case BTRFS_EXCLOP_BALANCE:
 432                 spin_lock(&fs_info->super_lock);
 433                 ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED);
 434                 fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE;
 435                 spin_unlock(&fs_info->super_lock);
 436                 break;
 437         default:
 438                 btrfs_warn(fs_info,
 439                         "invalid exclop balance operation %d requested", op);
 440         }
 441 }
 442
 443 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 444 {
 445         struct inode *inode = file_inode(file);
 446
 447         return put_user(inode->i_generation, arg);
 448 }
 449
 450 static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
 451                                         void __user *arg)
 452 {
 453         struct btrfs_device *device;
 454         struct request_queue *q;
 455         struct fstrim_range range;
 456         u64 minlen = ULLONG_MAX;
 457         u64 num_devices = 0;
 458         int ret;
 459
 460         if (!capable(CAP_SYS_ADMIN))
 461                 return -EPERM;
 462
 463         /*
 464          * btrfs_trim_block_group() depends on space cache, which is not
 465          * available in zoned filesystem. So, disallow fitrim on a zoned
 466          * filesystem for now.
 467          */
 468         if (btrfs_is_zoned(fs_info))
 469                 return -EOPNOTSUPP;
 470
 471         /*
 472          * If the fs is mounted with nologreplay, which requires it to be
 473          * mounted in RO mode as well, we can not allow discard on free space
 474          * inside block groups, because log trees refer to extents that are not
 475          * pinned in a block group's free space cache (pinning the extents is
 476          * precisely the first phase of replaying a log tree).
 477          */
 478         if (btrfs_test_opt(fs_info, NOLOGREPLAY))
 479                 return -EROFS;
 480
 481         rcu_read_lock();
 482         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 483                                 dev_list) {
 484                 if (!device->bdev)
 485                         continue;
 486                 q = bdev_get_queue(device->bdev);
 487                 if (blk_queue_discard(q)) {
 488                         num_devices++;
 489                         minlen = min_t(u64, q->limits.discard_granularity,
 490                                      minlen);
 491                 }
 492         }
 493         rcu_read_unlock();
 494
 495         if (!num_devices)
 496                 return -EOPNOTSUPP;
 497         if (copy_from_user(&range, arg, sizeof(range)))
 498                 return -EFAULT;
 499
 500         /*
 501          * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
 502          * block group is in the logical address space, which can be any
 503          * sectorsize aligned bytenr in  the range [0, U64_MAX].
 504          */
 505         if (range.len < fs_info->sb->s_blocksize)
 506                 return -EINVAL;
 507
 508         range.minlen = max(range.minlen, minlen);
 509         ret = btrfs_trim_fs(fs_info, &range);
 510         if (ret < 0)
 511                 return ret;
 512
 513         if (copy_to_user(arg, &range, sizeof(range)))
 514                 return -EFAULT;
 515
 516         return 0;
 517 }
 518
 519 int __pure btrfs_is_empty_uuid(u8 *uuid)
 520 {
 521         int i;
 522
 523         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 524                 if (uuid[i])
 525                         return 0;
 526         }
 527         return 1;
 528 }
 529
 530 static noinline int create_subvol(struct user_namespace *mnt_userns,
 531                                   struct inode *dir, struct dentry *dentry,
 532                                   const char *name, int namelen,
 533                                   struct btrfs_qgroup_inherit *inherit)
 534 {
 535         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 536         struct btrfs_trans_handle *trans;
 537         struct btrfs_key key;
 538         struct btrfs_root_item *root_item;
 539         struct btrfs_inode_item *inode_item;
 540         struct extent_buffer *leaf;
 541         struct btrfs_root *root = BTRFS_I(dir)->root;
 542         struct btrfs_root *new_root;
 543         struct btrfs_block_rsv block_rsv;
 544         struct timespec64 cur_time = current_time(dir);
 545         struct inode *inode;
 546         int ret;
 547         dev_t anon_dev = 0;
 548         u64 objectid;
 549         u64 index = 0;
 550
 551         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 552         if (!root_item)
 553                 return -ENOMEM;
 554
 555         ret = btrfs_get_free_objectid(fs_info->tree_root, &objectid);
 556         if (ret)
 557                 goto fail_free;
 558
 559         ret = get_anon_bdev(&anon_dev);
 560         if (ret < 0)
 561                 goto fail_free;
 562
 563         /*
 564          * Don't create subvolume whose level is not zero. Or qgroup will be
 565          * screwed up since it assumes subvolume qgroup's level to be 0.
 566          */
 567         if (btrfs_qgroup_level(objectid)) {
 568                 ret = -ENOSPC;
 569                 goto fail_free;
 570         }
 571
 572         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 573         /*
 574          * The same as the snapshot creation, please see the comment
 575          * of create_snapshot().
 576          */
 577         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
 578         if (ret)
 579                 goto fail_free;
 580
 581         trans = btrfs_start_transaction(root, 0);
 582         if (IS_ERR(trans)) {
 583                 ret = PTR_ERR(trans);
 584                 btrfs_subvolume_release_metadata(root, &block_rsv);
 585                 goto fail_free;
 586         }
 587         trans->block_rsv = &block_rsv;
 588         trans->bytes_reserved = block_rsv.size;
 589
 590         ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
 591         if (ret)
 592                 goto fail;
 593
 594         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
 595                                       BTRFS_NESTING_NORMAL);
 596         if (IS_ERR(leaf)) {
 597                 ret = PTR_ERR(leaf);
 598                 goto fail;
 599         }
 600
 601         btrfs_mark_buffer_dirty(leaf);
 602
 603         inode_item = &root_item->inode;
 604         btrfs_set_stack_inode_generation(inode_item, 1);
 605         btrfs_set_stack_inode_size(inode_item, 3);
 606         btrfs_set_stack_inode_nlink(inode_item, 1);
 607         btrfs_set_stack_inode_nbytes(inode_item,
 608                                      fs_info->nodesize);
 609         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 610
 611         btrfs_set_root_flags(root_item, 0);
 612         btrfs_set_root_limit(root_item, 0);
 613         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 614
 615         btrfs_set_root_bytenr(root_item, leaf->start);
 616         btrfs_set_root_generation(root_item, trans->transid);
 617         btrfs_set_root_level(root_item, 0);
 618         btrfs_set_root_refs(root_item, 1);
 619         btrfs_set_root_used(root_item, leaf->len);
 620         btrfs_set_root_last_snapshot(root_item, 0);
 621
 622         btrfs_set_root_generation_v2(root_item,
 623                         btrfs_root_generation(root_item));
 624         generate_random_guid(root_item->uuid);
 625         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 626         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 627         root_item->ctime = root_item->otime;
 628         btrfs_set_root_ctransid(root_item, trans->transid);
 629         btrfs_set_root_otransid(root_item, trans->transid);
 630
 631         btrfs_tree_unlock(leaf);
 632
 633         btrfs_set_root_dirid(root_item, BTRFS_FIRST_FREE_OBJECTID);
 634
 635         key.objectid = objectid;
 636         key.offset = 0;
 637         key.type = BTRFS_ROOT_ITEM_KEY;
 638         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 639                                 root_item);
 640         if (ret) {
 641                 /*
 642                  * Since we don't abort the transaction in this case, free the
 643                  * tree block so that we don't leak space and leave the
 644                  * filesystem in an inconsistent state (an extent item in the
 645                  * extent tree with a backreference for a root that does not
 646                  * exists).
 647                  */
 648                 btrfs_tree_lock(leaf);
 649                 btrfs_clean_tree_block(leaf);
 650                 btrfs_tree_unlock(leaf);
 651                 btrfs_free_tree_block(trans, objectid, leaf, 0, 1);
 652                 free_extent_buffer(leaf);
 653                 goto fail;
 654         }
 655
 656         free_extent_buffer(leaf);
 657         leaf = NULL;
 658
 659         key.offset = (u64)-1;
 660         new_root = btrfs_get_new_fs_root(fs_info, objectid, anon_dev);
 661         if (IS_ERR(new_root)) {
 662                 free_anon_bdev(anon_dev);
 663                 ret = PTR_ERR(new_root);
 664                 btrfs_abort_transaction(trans, ret);
 665                 goto fail;
 666         }
 667         /* Freeing will be done in btrfs_put_root() of new_root */
 668         anon_dev = 0;
 669
 670         ret = btrfs_record_root_in_trans(trans, new_root);
 671         if (ret) {
 672                 btrfs_put_root(new_root);
 673                 btrfs_abort_transaction(trans, ret);
 674                 goto fail;
 675         }
 676
 677         ret = btrfs_create_subvol_root(trans, new_root, root, mnt_userns);
 678         btrfs_put_root(new_root);
 679         if (ret) {
 680                 /* We potentially lose an unused inode item here */
 681                 btrfs_abort_transaction(trans, ret);
 682                 goto fail;
 683         }
 684
 685         /*
 686          * insert the directory item
 687          */
 688         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 689         if (ret) {
 690                 btrfs_abort_transaction(trans, ret);
 691                 goto fail;
 692         }
 693
 694         ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
 695                                     BTRFS_FT_DIR, index);
 696         if (ret) {
 697                 btrfs_abort_transaction(trans, ret);
 698                 goto fail;
 699         }
 700
 701         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 702         ret = btrfs_update_inode(trans, root, BTRFS_I(dir));
 703         if (ret) {
 704                 btrfs_abort_transaction(trans, ret);
 705                 goto fail;
 706         }
 707
 708         ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
 709                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 710         if (ret) {
 711                 btrfs_abort_transaction(trans, ret);
 712                 goto fail;
 713         }
 714
 715         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 716                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 717         if (ret)
 718                 btrfs_abort_transaction(trans, ret);
 719
 720 fail:
 721         kfree(root_item);
 722         trans->block_rsv = NULL;
 723         trans->bytes_reserved = 0;
 724         btrfs_subvolume_release_metadata(root, &block_rsv);
 725
 726         if (ret)
 727                 btrfs_end_transaction(trans);
 728         else
 729                 ret = btrfs_commit_transaction(trans);
 730
 731         if (!ret) {
 732                 inode = btrfs_lookup_dentry(dir, dentry);
 733                 if (IS_ERR(inode))
 734                         return PTR_ERR(inode);
 735                 d_instantiate(dentry, inode);
 736         }
 737         return ret;
 738
 739 fail_free:
 740         if (anon_dev)
 741                 free_anon_bdev(anon_dev);
 742         kfree(root_item);
 743         return ret;
 744 }
 745
 746 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 747                            struct dentry *dentry, bool readonly,
 748                            struct btrfs_qgroup_inherit *inherit)
 749 {
 750         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 751         struct inode *inode;
 752         struct btrfs_pending_snapshot *pending_snapshot;
 753         struct btrfs_trans_handle *trans;
 754         int ret;
 755
 756         if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
 757                 return -EINVAL;
 758
 759         if (atomic_read(&root->nr_swapfiles)) {
 760                 btrfs_warn(fs_info,
 761                            "cannot snapshot subvolume with active swapfile");
 762                 return -ETXTBSY;
 763         }
 764
 765         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 766         if (!pending_snapshot)
 767                 return -ENOMEM;
 768
 769         ret = get_anon_bdev(&pending_snapshot->anon_dev);
 770         if (ret < 0)
 771                 goto free_pending;
 772         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 773                         GFP_KERNEL);
 774         pending_snapshot->path = btrfs_alloc_path();
 775         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 776                 ret = -ENOMEM;
 777                 goto free_pending;
 778         }
 779
 780         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 781                              BTRFS_BLOCK_RSV_TEMP);
 782         /*
 783          * 1 - parent dir inode
 784          * 2 - dir entries
 785          * 1 - root item
 786          * 2 - root ref/backref
 787          * 1 - root of snapshot
 788          * 1 - UUID item
 789          */
 790         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 791                                         &pending_snapshot->block_rsv, 8,
 792                                         false);
 793         if (ret)
 794                 goto free_pending;
 795
 796         pending_snapshot->dentry = dentry;
 797         pending_snapshot->root = root;
 798         pending_snapshot->readonly = readonly;
 799         pending_snapshot->dir = dir;
 800         pending_snapshot->inherit = inherit;
 801
 802         trans = btrfs_start_transaction(root, 0);
 803         if (IS_ERR(trans)) {
 804                 ret = PTR_ERR(trans);
 805                 goto fail;
 806         }
 807
 808         trans->pending_snapshot = pending_snapshot;
 809
 810         ret = btrfs_commit_transaction(trans);
 811         if (ret)
 812                 goto fail;
 813
 814         ret = pending_snapshot->error;
 815         if (ret)
 816                 goto fail;
 817
 818         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 819         if (ret)
 820                 goto fail;
 821
 822         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 823         if (IS_ERR(inode)) {
 824                 ret = PTR_ERR(inode);
 825                 goto fail;
 826         }
 827
 828         d_instantiate(dentry, inode);
 829         ret = 0;
 830         pending_snapshot->anon_dev = 0;
 831 fail:
 832         /* Prevent double freeing of anon_dev */
 833         if (ret && pending_snapshot->snap)
 834                 pending_snapshot->snap->anon_dev = 0;
 835         btrfs_put_root(pending_snapshot->snap);
 836         btrfs_subvolume_release_metadata(root, &pending_snapshot->block_rsv);
 837 free_pending:
 838         if (pending_snapshot->anon_dev)
 839                 free_anon_bdev(pending_snapshot->anon_dev);
 840         kfree(pending_snapshot->root_item);
 841         btrfs_free_path(pending_snapshot->path);
 842         kfree(pending_snapshot);
 843
 844         return ret;
 845 }
 846
 847 /*  copy of may_delete in fs/namei.c()
 848  *      Check whether we can remove a link victim from directory dir, check
 849  *  whether the type of victim is right.
 850  *  1. We can't do it if dir is read-only (done in permission())
 851  *  2. We should have write and exec permissions on dir
 852  *  3. We can't remove anything from append-only dir
 853  *  4. We can't do anything with immutable dir (done in permission())
 854  *  5. If the sticky bit on dir is set we should either
 855  *      a. be owner of dir, or
 856  *      b. be owner of victim, or
 857  *      c. have CAP_FOWNER capability
 858  *  6. If the victim is append-only or immutable we can't do anything with
 859  *     links pointing to it.
 860  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 861  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 862  *  9. We can't remove a root or mountpoint.
 863  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 864  *     nfs_async_unlink().
 865  */
 866
 867 static int btrfs_may_delete(struct user_namespace *mnt_userns,
 868                             struct inode *dir, struct dentry *victim, int isdir)
 869 {
 870         int error;
 871
 872         if (d_really_is_negative(victim))
 873                 return -ENOENT;
 874
 875         BUG_ON(d_inode(victim->d_parent) != dir);
 876         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 877
 878         error = inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
 879         if (error)
 880                 return error;
 881         if (IS_APPEND(dir))
 882                 return -EPERM;
 883         if (check_sticky(mnt_userns, dir, d_inode(victim)) ||
 884             IS_APPEND(d_inode(victim)) || IS_IMMUTABLE(d_inode(victim)) ||
 885             IS_SWAPFILE(d_inode(victim)))
 886                 return -EPERM;
 887         if (isdir) {
 888                 if (!d_is_dir(victim))
 889                         return -ENOTDIR;
 890                 if (IS_ROOT(victim))
 891                         return -EBUSY;
 892         } else if (d_is_dir(victim))
 893                 return -EISDIR;
 894         if (IS_DEADDIR(dir))
 895                 return -ENOENT;
 896         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 897                 return -EBUSY;
 898         return 0;
 899 }
 900
 901 /* copy of may_create in fs/namei.c() */
 902 static inline int btrfs_may_create(struct user_namespace *mnt_userns,
 903                                    struct inode *dir, struct dentry *child)
 904 {
 905         if (d_really_is_positive(child))
 906                 return -EEXIST;
 907         if (IS_DEADDIR(dir))
 908                 return -ENOENT;
 909         if (!fsuidgid_has_mapping(dir->i_sb, mnt_userns))
 910                 return -EOVERFLOW;
 911         return inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
 912 }
 913
 914 /*
 915  * Create a new subvolume below @parent.  This is largely modeled after
 916  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 917  * inside this filesystem so it's quite a bit simpler.
 918  */
 919 static noinline int btrfs_mksubvol(const struct path *parent,
 920                                    struct user_namespace *mnt_userns,
 921                                    const char *name, int namelen,
 922                                    struct btrfs_root *snap_src,
 923                                    bool readonly,
 924                                    struct btrfs_qgroup_inherit *inherit)
 925 {
 926         struct inode *dir = d_inode(parent->dentry);
 927         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 928         struct dentry *dentry;
 929         int error;
 930
 931         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 932         if (error == -EINTR)
 933                 return error;
 934
 935         dentry = lookup_one(mnt_userns, name, parent->dentry, namelen);
 936         error = PTR_ERR(dentry);
 937         if (IS_ERR(dentry))
 938                 goto out_unlock;
 939
 940         error = btrfs_may_create(mnt_userns, dir, dentry);
 941         if (error)
 942                 goto out_dput;
 943
 944         /*
 945          * even if this name doesn't exist, we may get hash collisions.
 946          * check for them now when we can safely fail
 947          */
 948         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 949                                                dir->i_ino, name,
 950                                                namelen);
 951         if (error)
 952                 goto out_dput;
 953
 954         down_read(&fs_info->subvol_sem);
 955
 956         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 957                 goto out_up_read;
 958
 959         if (snap_src)
 960                 error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
 961         else
 962                 error = create_subvol(mnt_userns, dir, dentry, name, namelen, inherit);
 963
 964         if (!error)
 965                 fsnotify_mkdir(dir, dentry);
 966 out_up_read:
 967         up_read(&fs_info->subvol_sem);
 968 out_dput:
 969         dput(dentry);
 970 out_unlock:
 971         btrfs_inode_unlock(dir, 0);
 972         return error;
 973 }
 974
 975 static noinline int btrfs_mksnapshot(const struct path *parent,
 976                                    struct user_namespace *mnt_userns,
 977                                    const char *name, int namelen,
 978                                    struct btrfs_root *root,
 979                                    bool readonly,
 980                                    struct btrfs_qgroup_inherit *inherit)
 981 {
 982         int ret;
 983         bool snapshot_force_cow = false;
 984
 985         /*
 986          * Force new buffered writes to reserve space even when NOCOW is
 987          * possible. This is to avoid later writeback (running dealloc) to
 988          * fallback to COW mode and unexpectedly fail with ENOSPC.
 989          */
 990         btrfs_drew_read_lock(&root->snapshot_lock);
 991
 992         ret = btrfs_start_delalloc_snapshot(root, false);
 993         if (ret)
 994                 goto out;
 995
 996         /*
 997          * All previous writes have started writeback in NOCOW mode, so now
 998          * we force future writes to fallback to COW mode during snapshot
 999          * creation.
1000          */
1001         atomic_inc(&root->snapshot_force_cow);
1002         snapshot_force_cow = true;
1003
1004         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
1005
1006         ret = btrfs_mksubvol(parent, mnt_userns, name, namelen,
1007                              root, readonly, inherit);
1008 out:
1009         if (snapshot_force_cow)
1010                 atomic_dec(&root->snapshot_force_cow);
1011         btrfs_drew_read_unlock(&root->snapshot_lock);
1012         return ret;
1013 }
1014
1015 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start,
1016                                                bool locked)
1017 {
1018         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1019         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1020         struct extent_map *em;
1021         const u32 sectorsize = BTRFS_I(inode)->root->fs_info->sectorsize;
1022
1023         /*
1024          * hopefully we have this extent in the tree already, try without
1025          * the full extent lock
1026          */
1027         read_lock(&em_tree->lock);
1028         em = lookup_extent_mapping(em_tree, start, sectorsize);
1029         read_unlock(&em_tree->lock);
1030
1031         if (!em) {
1032                 struct extent_state *cached = NULL;
1033                 u64 end = start + sectorsize - 1;
1034
1035                 /* get the big lock and read metadata off disk */
1036                 if (!locked)
1037                         lock_extent_bits(io_tree, start, end, &cached);
1038                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, sectorsize);
1039                 if (!locked)
1040                         unlock_extent_cached(io_tree, start, end, &cached);
1041
1042                 if (IS_ERR(em))
1043                         return NULL;
1044         }
1045
1046         return em;
1047 }
1048
1049 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em,
1050                                      bool locked)
1051 {
1052         struct extent_map *next;
1053         bool ret = true;
1054
1055         /* this is the last extent */
1056         if (em->start + em->len >= i_size_read(inode))
1057                 return false;
1058
1059         next = defrag_lookup_extent(inode, em->start + em->len, locked);
1060         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1061                 ret = false;
1062         else if ((em->block_start + em->block_len == next->block_start) &&
1063                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1064                 ret = false;
1065
1066         free_extent_map(next);
1067         return ret;
1068 }
1069
1070 /*
1071  * Prepare one page to be defragged.
1072  *
1073  * This will ensure:
1074  *
1075  * - Returned page is locked and has been set up properly.
1076  * - No ordered extent exists in the page.
1077  * - The page is uptodate.
1078  *
1079  * NOTE: Caller should also wait for page writeback after the cluster is
1080  * prepared, here we don't do writeback wait for each page.
1081  */
1082 static struct page *defrag_prepare_one_page(struct btrfs_inode *inode,
1083                                             pgoff_t index)
1084 {
1085         struct address_space *mapping = inode->vfs_inode.i_mapping;
1086         gfp_t mask = btrfs_alloc_write_mask(mapping);
1087         u64 page_start = (u64)index << PAGE_SHIFT;
1088         u64 page_end = page_start + PAGE_SIZE - 1;
1089         struct extent_state *cached_state = NULL;
1090         struct page *page;
1091         int ret;
1092
1093 again:
1094         page = find_or_create_page(mapping, index, mask);
1095         if (!page)
1096                 return ERR_PTR(-ENOMEM);
1097
1098         /*
1099          * Since we can defragment files opened read-only, we can encounter
1100          * transparent huge pages here (see CONFIG_READ_ONLY_THP_FOR_FS). We
1101          * can't do I/O using huge pages yet, so return an error for now.
1102          * Filesystem transparent huge pages are typically only used for
1103          * executables that explicitly enable them, so this isn't very
1104          * restrictive.
1105          */
1106         if (PageCompound(page)) {
1107                 unlock_page(page);
1108                 put_page(page);
1109                 return ERR_PTR(-ETXTBSY);
1110         }
1111
1112         ret = set_page_extent_mapped(page);
1113         if (ret < 0) {
1114                 unlock_page(page);
1115                 put_page(page);
1116                 return ERR_PTR(ret);
1117         }
1118
1119         /* Wait for any existing ordered extent in the range */
1120         while (1) {
1121                 struct btrfs_ordered_extent *ordered;
1122
1123                 lock_extent_bits(&inode->io_tree, page_start, page_end, &cached_state);
1124                 ordered = btrfs_lookup_ordered_range(inode, page_start, PAGE_SIZE);
1125                 unlock_extent_cached(&inode->io_tree, page_start, page_end,
1126                                      &cached_state);
1127                 if (!ordered)
1128                         break;
1129
1130                 unlock_page(page);
1131                 btrfs_start_ordered_extent(ordered, 1);
1132                 btrfs_put_ordered_extent(ordered);
1133                 lock_page(page);
1134                 /*
1135                  * We unlocked the page above, so we need check if it was
1136                  * released or not.
1137                  */
1138                 if (page->mapping != mapping || !PagePrivate(page)) {
1139                         unlock_page(page);
1140                         put_page(page);
1141                         goto again;
1142                 }
1143         }
1144
1145         /*
1146          * Now the page range has no ordered extent any more.  Read the page to
1147          * make it uptodate.
1148          */
1149         if (!PageUptodate(page)) {
1150                 btrfs_readpage(NULL, page);
1151                 lock_page(page);
1152                 if (page->mapping != mapping || !PagePrivate(page)) {
1153                         unlock_page(page);
1154                         put_page(page);
1155                         goto again;
1156                 }
1157                 if (!PageUptodate(page)) {
1158                         unlock_page(page);
1159                         put_page(page);
1160                         return ERR_PTR(-EIO);
1161                 }
1162         }
1163         return page;
1164 }
1165
1166 struct defrag_target_range {
1167         struct list_head list;
1168         u64 start;
1169         u64 len;
1170 };
1171
1172 /*
1173  * Collect all valid target extents.
1174  *
1175  * @start:         file offset to lookup
1176  * @len:           length to lookup
1177  * @extent_thresh: file extent size threshold, any extent size >= this value
1178  *                 will be ignored
1179  * @newer_than:    only defrag extents newer than this value
1180  * @do_compress:   whether the defrag is doing compression
1181  *                 if true, @extent_thresh will be ignored and all regular
1182  *                 file extents meeting @newer_than will be targets.
1183  * @locked:        if the range has already held extent lock
1184  * @target_list:   list of targets file extents
1185  */
1186 static int defrag_collect_targets(struct btrfs_inode *inode,
1187                                   u64 start, u64 len, u32 extent_thresh,
1188                                   u64 newer_than, bool do_compress,
1189                                   bool locked, struct list_head *target_list)
1190 {
1191         u64 cur = start;
1192         int ret = 0;
1193
1194         while (cur < start + len) {
1195                 struct extent_map *em;
1196                 struct defrag_target_range *new;
1197                 bool next_mergeable = true;
1198                 u64 range_len;
1199
1200                 em = defrag_lookup_extent(&inode->vfs_inode, cur, locked);
1201                 if (!em)
1202                         break;
1203
1204                 /* Skip hole/inline/preallocated extents */
1205                 if (em->block_start >= EXTENT_MAP_LAST_BYTE ||
1206                     test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
1207                         goto next;
1208
1209                 /* Skip older extent */
1210                 if (em->generation < newer_than)
1211                         goto next;
1212
1213                 /*
1214                  * Our start offset might be in the middle of an existing extent
1215                  * map, so take that into account.
1216                  */
1217                 range_len = em->len - (cur - em->start);
1218                 /*
1219                  * If this range of the extent map is already flagged for delalloc,
1220                  * skip it, because:
1221                  *
1222                  * 1) We could deadlock later, when trying to reserve space for
1223                  *    delalloc, because in case we can't immediately reserve space
1224                  *    the flusher can start delalloc and wait for the respective
1225                  *    ordered extents to complete. The deadlock would happen
1226                  *    because we do the space reservation while holding the range
1227                  *    locked, and starting writeback, or finishing an ordered
1228                  *    extent, requires locking the range;
1229                  *
1230                  * 2) If there's delalloc there, it means there's dirty pages for
1231                  *    which writeback has not started yet (we clean the delalloc
1232                  *    flag when starting writeback and after creating an ordered
1233                  *    extent). If we mark pages in an adjacent range for defrag,
1234                  *    then we will have a larger contiguous range for delalloc,
1235                  *    very likely resulting in a larger extent after writeback is
1236                  *    triggered (except in a case of free space fragmentation).
1237                  */
1238                 if (test_range_bit(&inode->io_tree, cur, cur + range_len - 1,
1239                                    EXTENT_DELALLOC, 0, NULL))
1240                         goto next;
1241
1242                 /*
1243                  * For do_compress case, we want to compress all valid file
1244                  * extents, thus no @extent_thresh or mergeable check.
1245                  */
1246                 if (do_compress)
1247                         goto add;
1248
1249                 /* Skip too large extent */
1250                 if (range_len >= extent_thresh)
1251                         goto next;
1252
1253                 next_mergeable = defrag_check_next_extent(&inode->vfs_inode, em,
1254                                                           locked);
1255                 if (!next_mergeable) {
1256                         struct defrag_target_range *last;
1257
1258                         /* Empty target list, no way to merge with last entry */
1259                         if (list_empty(target_list))
1260                                 goto next;
1261                         last = list_entry(target_list->prev,
1262                                           struct defrag_target_range, list);
1263                         /* Not mergeable with last entry */
1264                         if (last->start + last->len != cur)
1265                                 goto next;
1266
1267                         /* Mergeable, fall through to add it to @target_list. */
1268                 }
1269
1270 add:
1271                 range_len = min(extent_map_end(em), start + len) - cur;
1272                 /*
1273                  * This one is a good target, check if it can be merged into
1274                  * last range of the target list.
1275                  */
1276                 if (!list_empty(target_list)) {
1277                         struct defrag_target_range *last;
1278
1279                         last = list_entry(target_list->prev,
1280                                           struct defrag_target_range, list);
1281                         ASSERT(last->start + last->len <= cur);
1282                         if (last->start + last->len == cur) {
1283                                 /* Mergeable, enlarge the last entry */
1284                                 last->len += range_len;
1285                                 goto next;
1286                         }
1287                         /* Fall through to allocate a new entry */
1288                 }
1289
1290                 /* Allocate new defrag_target_range */
1291                 new = kmalloc(sizeof(*new), GFP_NOFS);
1292                 if (!new) {
1293                         free_extent_map(em);
1294                         ret = -ENOMEM;
1295                         break;
1296                 }
1297                 new->start = cur;
1298                 new->len = range_len;
1299                 list_add_tail(&new->list, target_list);
1300
1301 next:
1302                 cur = extent_map_end(em);
1303                 free_extent_map(em);
1304         }
1305         if (ret < 0) {
1306                 struct defrag_target_range *entry;
1307                 struct defrag_target_range *tmp;
1308
1309                 list_for_each_entry_safe(entry, tmp, target_list, list) {
1310                         list_del_init(&entry->list);
1311                         kfree(entry);
1312                 }
1313         }
1314         return ret;
1315 }
1316
1317 #define CLUSTER_SIZE    (SZ_256K)
1318
1319 /*
1320  * Defrag one contiguous target range.
1321  *
1322  * @inode:      target inode
1323  * @target:     target range to defrag
1324  * @pages:      locked pages covering the defrag range
1325  * @nr_pages:   number of locked pages
1326  *
1327  * Caller should ensure:
1328  *
1329  * - Pages are prepared
1330  *   Pages should be locked, no ordered extent in the pages range,
1331  *   no writeback.
1332  *
1333  * - Extent bits are locked
1334  */
1335 static int defrag_one_locked_target(struct btrfs_inode *inode,
1336                                     struct defrag_target_range *target,
1337                                     struct page **pages, int nr_pages,
1338                                     struct extent_state **cached_state)
1339 {
1340         struct btrfs_fs_info *fs_info = inode->root->fs_info;
1341         struct extent_changeset *data_reserved = NULL;
1342         const u64 start = target->start;
1343         const u64 len = target->len;
1344         unsigned long last_index = (start + len - 1) >> PAGE_SHIFT;
1345         unsigned long start_index = start >> PAGE_SHIFT;
1346         unsigned long first_index = page_index(pages[0]);
1347         int ret = 0;
1348         int i;
1349
1350         ASSERT(last_index - first_index + 1 <= nr_pages);
1351
1352         ret = btrfs_delalloc_reserve_space(inode, &data_reserved, start, len);
1353         if (ret < 0)
1354                 return ret;
1355         clear_extent_bit(&inode->io_tree, start, start + len - 1,
1356                          EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
1357                          EXTENT_DEFRAG, 0, 0, cached_state);
1358         set_extent_defrag(&inode->io_tree, start, start + len - 1, cached_state);
1359
1360         /* Update the page status */
1361         for (i = start_index - first_index; i <= last_index - first_index; i++) {
1362                 ClearPageChecked(pages[i]);
1363                 btrfs_page_clamp_set_dirty(fs_info, pages[i], start, len);
1364         }
1365         btrfs_delalloc_release_extents(inode, len);
1366         extent_changeset_free(data_reserved);
1367
1368         return ret;
1369 }
1370
1371 static int defrag_one_range(struct btrfs_inode *inode, u64 start, u32 len,
1372                             u32 extent_thresh, u64 newer_than, bool do_compress)
1373 {
1374         struct extent_state *cached_state = NULL;
1375         struct defrag_target_range *entry;
1376         struct defrag_target_range *tmp;
1377         LIST_HEAD(target_list);
1378         struct page **pages;
1379         const u32 sectorsize = inode->root->fs_info->sectorsize;
1380         u64 last_index = (start + len - 1) >> PAGE_SHIFT;
1381         u64 start_index = start >> PAGE_SHIFT;
1382         unsigned int nr_pages = last_index - start_index + 1;
1383         int ret = 0;
1384         int i;
1385
1386         ASSERT(nr_pages <= CLUSTER_SIZE / PAGE_SIZE);
1387         ASSERT(IS_ALIGNED(start, sectorsize) && IS_ALIGNED(len, sectorsize));
1388
1389         pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
1390         if (!pages)
1391                 return -ENOMEM;
1392
1393         /* Prepare all pages */
1394         for (i = 0; i < nr_pages; i++) {
1395                 pages[i] = defrag_prepare_one_page(inode, start_index + i);
1396                 if (IS_ERR(pages[i])) {
1397                         ret = PTR_ERR(pages[i]);
1398                         pages[i] = NULL;
1399                         goto free_pages;
1400                 }
1401         }
1402         for (i = 0; i < nr_pages; i++)
1403                 wait_on_page_writeback(pages[i]);
1404
1405         /* Lock the pages range */
1406         lock_extent_bits(&inode->io_tree, start_index << PAGE_SHIFT,
1407                          (last_index << PAGE_SHIFT) + PAGE_SIZE - 1,
1408                          &cached_state);
1409         /*
1410          * Now we have a consistent view about the extent map, re-check
1411          * which range really needs to be defragged.
1412          *
1413          * And this time we have extent locked already, pass @locked = true
1414          * so that we won't relock the extent range and cause deadlock.
1415          */
1416         ret = defrag_collect_targets(inode, start, len, extent_thresh,
1417                                      newer_than, do_compress, true,
1418                                      &target_list);
1419         if (ret < 0)
1420                 goto unlock_extent;
1421
1422         list_for_each_entry(entry, &target_list, list) {
1423                 ret = defrag_one_locked_target(inode, entry, pages, nr_pages,
1424                                                &cached_state);
1425                 if (ret < 0)
1426                         break;
1427         }
1428
1429         list_for_each_entry_safe(entry, tmp, &target_list, list) {
1430                 list_del_init(&entry->list);
1431                 kfree(entry);
1432         }
1433 unlock_extent:
1434         unlock_extent_cached(&inode->io_tree, start_index << PAGE_SHIFT,
1435                              (last_index << PAGE_SHIFT) + PAGE_SIZE - 1,
1436                              &cached_state);
1437 free_pages:
1438         for (i = 0; i < nr_pages; i++) {
1439                 if (pages[i]) {
1440                         unlock_page(pages[i]);
1441                         put_page(pages[i]);
1442                 }
1443         }
1444         kfree(pages);
1445         return ret;
1446 }
1447
1448 static int defrag_one_cluster(struct btrfs_inode *inode,
1449                               struct file_ra_state *ra,
1450                               u64 start, u32 len, u32 extent_thresh,
1451                               u64 newer_than, bool do_compress,
1452                               unsigned long *sectors_defragged,
1453                               unsigned long max_sectors)
1454 {
1455         const u32 sectorsize = inode->root->fs_info->sectorsize;
1456         struct defrag_target_range *entry;
1457         struct defrag_target_range *tmp;
1458         LIST_HEAD(target_list);
1459         int ret;
1460
1461         BUILD_BUG_ON(!IS_ALIGNED(CLUSTER_SIZE, PAGE_SIZE));
1462         ret = defrag_collect_targets(inode, start, len, extent_thresh,
1463                                      newer_than, do_compress, false,
1464                                      &target_list);
1465         if (ret < 0)
1466                 goto out;
1467
1468         list_for_each_entry(entry, &target_list, list) {
1469                 u32 range_len = entry->len;
1470
1471                 /* Reached or beyond the limit */
1472                 if (max_sectors && *sectors_defragged >= max_sectors) {
1473                         ret = 1;
1474                         break;
1475                 }
1476
1477                 if (max_sectors)
1478                         range_len = min_t(u32, range_len,
1479                                 (max_sectors - *sectors_defragged) * sectorsize);
1480
1481                 if (ra)
1482                         page_cache_sync_readahead(inode->vfs_inode.i_mapping,
1483                                 ra, NULL, entry->start >> PAGE_SHIFT,
1484                                 ((entry->start + range_len - 1) >> PAGE_SHIFT) -
1485                                 (entry->start >> PAGE_SHIFT) + 1);
1486                 /*
1487                  * Here we may not defrag any range if holes are punched before
1488                  * we locked the pages.
1489                  * But that's fine, it only affects the @sectors_defragged
1490                  * accounting.
1491                  */
1492                 ret = defrag_one_range(inode, entry->start, range_len,
1493                                        extent_thresh, newer_than, do_compress);
1494                 if (ret < 0)
1495                         break;
1496                 *sectors_defragged += range_len >>
1497                                       inode->root->fs_info->sectorsize_bits;
1498         }
1499 out:
1500         list_for_each_entry_safe(entry, tmp, &target_list, list) {
1501                 list_del_init(&entry->list);
1502                 kfree(entry);
1503         }
1504         return ret;
1505 }
1506
1507 /*
1508  * Entry point to file defragmentation.
1509  *
1510  * @inode:         inode to be defragged
1511  * @ra:            readahead state (can be NUL)
1512  * @range:         defrag options including range and flags
1513  * @newer_than:    minimum transid to defrag
1514  * @max_to_defrag: max number of sectors to be defragged, if 0, the whole inode
1515  *                 will be defragged.
1516  *
1517  * Return <0 for error.
1518  * Return >=0 for the number of sectors defragged, and range->start will be updated
1519  * to indicate the file offset where next defrag should be started at.
1520  * (Mostly for autodefrag, which sets @max_to_defrag thus we may exit early without
1521  *  defragging all the range).
1522  */
1523 int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra,
1524                       struct btrfs_ioctl_defrag_range_args *range,
1525                       u64 newer_than, unsigned long max_to_defrag)
1526 {
1527         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1528         unsigned long sectors_defragged = 0;
1529         u64 isize = i_size_read(inode);
1530         u64 cur;
1531         u64 last_byte;
1532         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1533         bool ra_allocated = false;
1534         int compress_type = BTRFS_COMPRESS_ZLIB;
1535         int ret = 0;
1536         u32 extent_thresh = range->extent_thresh;
1537         pgoff_t start_index;
1538
1539         if (isize == 0)
1540                 return 0;
1541
1542         if (range->start >= isize)
1543                 return -EINVAL;
1544
1545         if (do_compress) {
1546                 if (range->compress_type >= BTRFS_NR_COMPRESS_TYPES)
1547                         return -EINVAL;
1548                 if (range->compress_type)
1549                         compress_type = range->compress_type;
1550         }
1551
1552         if (extent_thresh == 0)
1553                 extent_thresh = SZ_256K;
1554
1555         if (range->start + range->len > range->start) {
1556                 /* Got a specific range */
1557                 last_byte = min(isize, range->start + range->len);
1558         } else {
1559                 /* Defrag until file end */
1560                 last_byte = isize;
1561         }
1562
1563         /* Align the range */
1564         cur = round_down(range->start, fs_info->sectorsize);
1565         last_byte = round_up(last_byte, fs_info->sectorsize) - 1;
1566
1567         /*
1568          * If we were not given a ra, allocate a readahead context. As
1569          * readahead is just an optimization, defrag will work without it so
1570          * we don't error out.
1571          */
1572         if (!ra) {
1573                 ra_allocated = true;
1574                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1575                 if (ra)
1576                         file_ra_state_init(ra, inode->i_mapping);
1577         }
1578
1579         /*
1580          * Make writeback start from the beginning of the range, so that the
1581          * defrag range can be written sequentially.
1582          */
1583         start_index = cur >> PAGE_SHIFT;
1584         if (start_index < inode->i_mapping->writeback_index)
1585                 inode->i_mapping->writeback_index = start_index;
1586
1587         while (cur < last_byte) {
1588                 const unsigned long prev_sectors_defragged = sectors_defragged;
1589                 u64 cluster_end;
1590
1591                 /* The cluster size 256K should always be page aligned */
1592                 BUILD_BUG_ON(!IS_ALIGNED(CLUSTER_SIZE, PAGE_SIZE));
1593
1594                 if (btrfs_defrag_cancelled(fs_info)) {
1595                         ret = -EAGAIN;
1596                         break;
1597                 }
1598
1599                 /* We want the cluster end at page boundary when possible */
1600                 cluster_end = (((cur >> PAGE_SHIFT) +
1601                                (SZ_256K >> PAGE_SHIFT)) << PAGE_SHIFT) - 1;
1602                 cluster_end = min(cluster_end, last_byte);
1603
1604                 btrfs_inode_lock(inode, 0);
1605                 if (IS_SWAPFILE(inode)) {
1606                         ret = -ETXTBSY;
1607                         btrfs_inode_unlock(inode, 0);
1608                         break;
1609                 }
1610                 if (!(inode->i_sb->s_flags & SB_ACTIVE)) {
1611                         btrfs_inode_unlock(inode, 0);
1612                         break;
1613                 }
1614                 if (do_compress)
1615                         BTRFS_I(inode)->defrag_compress = compress_type;
1616                 ret = defrag_one_cluster(BTRFS_I(inode), ra, cur,
1617                                 cluster_end + 1 - cur, extent_thresh,
1618                                 newer_than, do_compress,
1619                                 &sectors_defragged, max_to_defrag);
1620
1621                 if (sectors_defragged > prev_sectors_defragged)
1622                         balance_dirty_pages_ratelimited(inode->i_mapping);
1623
1624                 btrfs_inode_unlock(inode, 0);
1625                 if (ret < 0)
1626                         break;
1627                 cur = cluster_end + 1;
1628                 if (ret > 0) {
1629                         ret = 0;
1630                         break;
1631                 }
1632         }
1633
1634         if (ra_allocated)
1635                 kfree(ra);
1636         /*
1637          * Update range.start for autodefrag, this will indicate where to start
1638          * in next run.
1639          */
1640         range->start = cur;
1641         if (sectors_defragged) {
1642                 /*
1643                  * We have defragged some sectors, for compression case they
1644                  * need to be written back immediately.
1645                  */
1646                 if (range->flags & BTRFS_DEFRAG_RANGE_START_IO) {
1647                         filemap_flush(inode->i_mapping);
1648                         if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1649                                      &BTRFS_I(inode)->runtime_flags))
1650                                 filemap_flush(inode->i_mapping);
1651                 }
1652                 if (range->compress_type == BTRFS_COMPRESS_LZO)
1653                         btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1654                 else if (range->compress_type == BTRFS_COMPRESS_ZSTD)
1655                         btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1656                 ret = sectors_defragged;
1657         }
1658         if (do_compress) {
1659                 btrfs_inode_lock(inode, 0);
1660                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1661                 btrfs_inode_unlock(inode, 0);
1662         }
1663         return ret;
1664 }
1665
1666 /*
1667  * Try to start exclusive operation @type or cancel it if it's running.
1668  *
1669  * Return:
1670  *   0        - normal mode, newly claimed op started
1671  *  >0        - normal mode, something else is running,
1672  *              return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS to user space
1673  * ECANCELED  - cancel mode, successful cancel
1674  * ENOTCONN   - cancel mode, operation not running anymore
1675  */
1676 static int exclop_start_or_cancel_reloc(struct btrfs_fs_info *fs_info,
1677                         enum btrfs_exclusive_operation type, bool cancel)
1678 {
1679         if (!cancel) {
1680                 /* Start normal op */
1681                 if (!btrfs_exclop_start(fs_info, type))
1682                         return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1683                 /* Exclusive operation is now claimed */
1684                 return 0;
1685         }
1686
1687         /* Cancel running op */
1688         if (btrfs_exclop_start_try_lock(fs_info, type)) {
1689                 /*
1690                  * This blocks any exclop finish from setting it to NONE, so we
1691                  * request cancellation. Either it runs and we will wait for it,
1692                  * or it has finished and no waiting will happen.
1693                  */
1694                 atomic_inc(&fs_info->reloc_cancel_req);
1695                 btrfs_exclop_start_unlock(fs_info);
1696
1697                 if (test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags))
1698                         wait_on_bit(&fs_info->flags, BTRFS_FS_RELOC_RUNNING,
1699                                     TASK_INTERRUPTIBLE);
1700
1701                 return -ECANCELED;
1702         }
1703
1704         /* Something else is running or none */
1705         return -ENOTCONN;
1706 }
1707
1708 static noinline int btrfs_ioctl_resize(struct file *file,
1709                                         void __user *arg)
1710 {
1711         BTRFS_DEV_LOOKUP_ARGS(args);
1712         struct inode *inode = file_inode(file);
1713         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1714         u64 new_size;
1715         u64 old_size;
1716         u64 devid = 1;
1717         struct btrfs_root *root = BTRFS_I(inode)->root;
1718         struct btrfs_ioctl_vol_args *vol_args;
1719         struct btrfs_trans_handle *trans;
1720         struct btrfs_device *device = NULL;
1721         char *sizestr;
1722         char *retptr;
1723         char *devstr = NULL;
1724         int ret = 0;
1725         int mod = 0;
1726         bool cancel;
1727
1728         if (!capable(CAP_SYS_ADMIN))
1729                 return -EPERM;
1730
1731         ret = mnt_want_write_file(file);
1732         if (ret)
1733                 return ret;
1734
1735         /*
1736          * Read the arguments before checking exclusivity to be able to
1737          * distinguish regular resize and cancel
1738          */
1739         vol_args = memdup_user(arg, sizeof(*vol_args));
1740         if (IS_ERR(vol_args)) {
1741                 ret = PTR_ERR(vol_args);
1742                 goto out_drop;
1743         }
1744         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1745         sizestr = vol_args->name;
1746         cancel = (strcmp("cancel", sizestr) == 0);
1747         ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_RESIZE, cancel);
1748         if (ret)
1749                 goto out_free;
1750         /* Exclusive operation is now claimed */
1751
1752         devstr = strchr(sizestr, ':');
1753         if (devstr) {
1754                 sizestr = devstr + 1;
1755                 *devstr = '\0';
1756                 devstr = vol_args->name;
1757                 ret = kstrtoull(devstr, 10, &devid);
1758                 if (ret)
1759                         goto out_finish;
1760                 if (!devid) {
1761                         ret = -EINVAL;
1762                         goto out_finish;
1763                 }
1764                 btrfs_info(fs_info, "resizing devid %llu", devid);
1765         }
1766
1767         args.devid = devid;
1768         device = btrfs_find_device(fs_info->fs_devices, &args);
1769         if (!device) {
1770                 btrfs_info(fs_info, "resizer unable to find device %llu",
1771                            devid);
1772                 ret = -ENODEV;
1773                 goto out_finish;
1774         }
1775
1776         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1777                 btrfs_info(fs_info,
1778                            "resizer unable to apply on readonly device %llu",
1779                        devid);
1780                 ret = -EPERM;
1781                 goto out_finish;
1782         }
1783
1784         if (!strcmp(sizestr, "max"))
1785                 new_size = bdev_nr_bytes(device->bdev);
1786         else {
1787                 if (sizestr[0] == '-') {
1788                         mod = -1;
1789                         sizestr++;
1790                 } else if (sizestr[0] == '+') {
1791                         mod = 1;
1792                         sizestr++;
1793                 }
1794                 new_size = memparse(sizestr, &retptr);
1795                 if (*retptr != '\0' || new_size == 0) {
1796                         ret = -EINVAL;
1797                         goto out_finish;
1798                 }
1799         }
1800
1801         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1802                 ret = -EPERM;
1803                 goto out_finish;
1804         }
1805
1806         old_size = btrfs_device_get_total_bytes(device);
1807
1808         if (mod < 0) {
1809                 if (new_size > old_size) {
1810                         ret = -EINVAL;
1811                         goto out_finish;
1812                 }
1813                 new_size = old_size - new_size;
1814         } else if (mod > 0) {
1815                 if (new_size > ULLONG_MAX - old_size) {
1816                         ret = -ERANGE;
1817                         goto out_finish;
1818                 }
1819                 new_size = old_size + new_size;
1820         }
1821
1822         if (new_size < SZ_256M) {
1823                 ret = -EINVAL;
1824                 goto out_finish;
1825         }
1826         if (new_size > bdev_nr_bytes(device->bdev)) {
1827                 ret = -EFBIG;
1828                 goto out_finish;
1829         }
1830
1831         new_size = round_down(new_size, fs_info->sectorsize);
1832
1833         if (new_size > old_size) {
1834                 trans = btrfs_start_transaction(root, 0);
1835                 if (IS_ERR(trans)) {
1836                         ret = PTR_ERR(trans);
1837                         goto out_finish;
1838                 }
1839                 ret = btrfs_grow_device(trans, device, new_size);
1840                 btrfs_commit_transaction(trans);
1841         } else if (new_size < old_size) {
1842                 ret = btrfs_shrink_device(device, new_size);
1843         } /* equal, nothing need to do */
1844
1845         if (ret == 0 && new_size != old_size)
1846                 btrfs_info_in_rcu(fs_info,
1847                         "resize device %s (devid %llu) from %llu to %llu",
1848                         rcu_str_deref(device->name), device->devid,
1849                         old_size, new_size);
1850 out_finish:
1851         btrfs_exclop_finish(fs_info);
1852 out_free:
1853         kfree(vol_args);
1854 out_drop:
1855         mnt_drop_write_file(file);
1856         return ret;
1857 }
1858
1859 static noinline int __btrfs_ioctl_snap_create(struct file *file,
1860                                 struct user_namespace *mnt_userns,
1861                                 const char *name, unsigned long fd, int subvol,
1862                                 bool readonly,
1863                                 struct btrfs_qgroup_inherit *inherit)
1864 {
1865         int namelen;
1866         int ret = 0;
1867
1868         if (!S_ISDIR(file_inode(file)->i_mode))
1869                 return -ENOTDIR;
1870
1871         ret = mnt_want_write_file(file);
1872         if (ret)
1873                 goto out;
1874
1875         namelen = strlen(name);
1876         if (strchr(name, '/')) {
1877                 ret = -EINVAL;
1878                 goto out_drop_write;
1879         }
1880
1881         if (name[0] == '.' &&
1882            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1883                 ret = -EEXIST;
1884                 goto out_drop_write;
1885         }
1886
1887         if (subvol) {
1888                 ret = btrfs_mksubvol(&file->f_path, mnt_userns, name,
1889                                      namelen, NULL, readonly, inherit);
1890         } else {
1891                 struct fd src = fdget(fd);
1892                 struct inode *src_inode;
1893                 if (!src.file) {
1894                         ret = -EINVAL;
1895                         goto out_drop_write;
1896                 }
1897
1898                 src_inode = file_inode(src.file);
1899                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1900                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1901                                    "Snapshot src from another FS");
1902                         ret = -EXDEV;
1903                 } else if (!inode_owner_or_capable(mnt_userns, src_inode)) {
1904                         /*
1905                          * Subvolume creation is not restricted, but snapshots
1906                          * are limited to own subvolumes only
1907                          */
1908                         ret = -EPERM;
1909                 } else {
1910                         ret = btrfs_mksnapshot(&file->f_path, mnt_userns,
1911                                                name, namelen,
1912                                                BTRFS_I(src_inode)->root,
1913                                                readonly, inherit);
1914                 }
1915                 fdput(src);
1916         }
1917 out_drop_write:
1918         mnt_drop_write_file(file);
1919 out:
1920         return ret;
1921 }
1922
1923 static noinline int btrfs_ioctl_snap_create(struct file *file,
1924                                             void __user *arg, int subvol)
1925 {
1926         struct btrfs_ioctl_vol_args *vol_args;
1927         int ret;
1928
1929         if (!S_ISDIR(file_inode(file)->i_mode))
1930                 return -ENOTDIR;
1931
1932         vol_args = memdup_user(arg, sizeof(*vol_args));
1933         if (IS_ERR(vol_args))
1934                 return PTR_ERR(vol_args);
1935         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1936
1937         ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file),
1938                                         vol_args->name, vol_args->fd, subvol,
1939                                         false, NULL);
1940
1941         kfree(vol_args);
1942         return ret;
1943 }
1944
1945 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1946                                                void __user *arg, int subvol)
1947 {
1948         struct btrfs_ioctl_vol_args_v2 *vol_args;
1949         int ret;
1950         bool readonly = false;
1951         struct btrfs_qgroup_inherit *inherit = NULL;
1952
1953         if (!S_ISDIR(file_inode(file)->i_mode))
1954                 return -ENOTDIR;
1955
1956         vol_args = memdup_user(arg, sizeof(*vol_args));
1957         if (IS_ERR(vol_args))
1958                 return PTR_ERR(vol_args);
1959         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1960
1961         if (vol_args->flags & ~BTRFS_SUBVOL_CREATE_ARGS_MASK) {
1962                 ret = -EOPNOTSUPP;
1963                 goto free_args;
1964         }
1965
1966         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1967                 readonly = true;
1968         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1969                 u64 nums;
1970
1971                 if (vol_args->size < sizeof(*inherit) ||
1972                     vol_args->size > PAGE_SIZE) {
1973                         ret = -EINVAL;
1974                         goto free_args;
1975                 }
1976                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1977                 if (IS_ERR(inherit)) {
1978                         ret = PTR_ERR(inherit);
1979                         goto free_args;
1980                 }
1981
1982                 if (inherit->num_qgroups > PAGE_SIZE ||
1983                     inherit->num_ref_copies > PAGE_SIZE ||
1984                     inherit->num_excl_copies > PAGE_SIZE) {
1985                         ret = -EINVAL;
1986                         goto free_inherit;
1987                 }
1988
1989                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
1990                        2 * inherit->num_excl_copies;
1991                 if (vol_args->size != struct_size(inherit, qgroups, nums)) {
1992                         ret = -EINVAL;
1993                         goto free_inherit;
1994                 }
1995         }
1996
1997         ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file),
1998                                         vol_args->name, vol_args->fd, subvol,
1999                                         readonly, inherit);
2000         if (ret)
2001                 goto free_inherit;
2002 free_inherit:
2003         kfree(inherit);
2004 free_args:
2005         kfree(vol_args);
2006         return ret;
2007 }
2008
2009 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
2010                                                 void __user *arg)
2011 {
2012         struct inode *inode = file_inode(file);
2013         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2014         struct btrfs_root *root = BTRFS_I(inode)->root;
2015         int ret = 0;
2016         u64 flags = 0;
2017
2018         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
2019                 return -EINVAL;
2020
2021         down_read(&fs_info->subvol_sem);
2022         if (btrfs_root_readonly(root))
2023                 flags |= BTRFS_SUBVOL_RDONLY;
2024         up_read(&fs_info->subvol_sem);
2025
2026         if (copy_to_user(arg, &flags, sizeof(flags)))
2027                 ret = -EFAULT;
2028
2029         return ret;
2030 }
2031
2032 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
2033                                               void __user *arg)
2034 {
2035         struct inode *inode = file_inode(file);
2036         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2037         struct btrfs_root *root = BTRFS_I(inode)->root;
2038         struct btrfs_trans_handle *trans;
2039         u64 root_flags;
2040         u64 flags;
2041         int ret = 0;
2042
2043         if (!inode_owner_or_capable(file_mnt_user_ns(file), inode))
2044                 return -EPERM;
2045
2046         ret = mnt_want_write_file(file);
2047         if (ret)
2048                 goto out;
2049
2050         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2051                 ret = -EINVAL;
2052                 goto out_drop_write;
2053         }
2054
2055         if (copy_from_user(&flags, arg, sizeof(flags))) {
2056                 ret = -EFAULT;
2057                 goto out_drop_write;
2058         }
2059
2060         if (flags & ~BTRFS_SUBVOL_RDONLY) {
2061                 ret = -EOPNOTSUPP;
2062                 goto out_drop_write;
2063         }
2064
2065         down_write(&fs_info->subvol_sem);
2066
2067         /* nothing to do */
2068         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
2069                 goto out_drop_sem;
2070
2071         root_flags = btrfs_root_flags(&root->root_item);
2072         if (flags & BTRFS_SUBVOL_RDONLY) {
2073                 btrfs_set_root_flags(&root->root_item,
2074                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
2075         } else {
2076                 /*
2077                  * Block RO -> RW transition if this subvolume is involved in
2078                  * send
2079                  */
2080                 spin_lock(&root->root_item_lock);
2081                 if (root->send_in_progress == 0) {
2082                         btrfs_set_root_flags(&root->root_item,
2083                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
2084                         spin_unlock(&root->root_item_lock);
2085                 } else {
2086                         spin_unlock(&root->root_item_lock);
2087                         btrfs_warn(fs_info,
2088                                    "Attempt to set subvolume %llu read-write during send",
2089                                    root->root_key.objectid);
2090                         ret = -EPERM;
2091                         goto out_drop_sem;
2092                 }
2093         }
2094
2095         trans = btrfs_start_transaction(root, 1);
2096         if (IS_ERR(trans)) {
2097                 ret = PTR_ERR(trans);
2098                 goto out_reset;
2099         }
2100
2101         ret = btrfs_update_root(trans, fs_info->tree_root,
2102                                 &root->root_key, &root->root_item);
2103         if (ret < 0) {
2104                 btrfs_end_transaction(trans);
2105                 goto out_reset;
2106         }
2107
2108         ret = btrfs_commit_transaction(trans);
2109
2110 out_reset:
2111         if (ret)
2112                 btrfs_set_root_flags(&root->root_item, root_flags);
2113 out_drop_sem:
2114         up_write(&fs_info->subvol_sem);
2115 out_drop_write:
2116         mnt_drop_write_file(file);
2117 out:
2118         return ret;
2119 }
2120
2121 static noinline int key_in_sk(struct btrfs_key *key,
2122                               struct btrfs_ioctl_search_key *sk)
2123 {
2124         struct btrfs_key test;
2125         int ret;
2126
2127         test.objectid = sk->min_objectid;
2128         test.type = sk->min_type;
2129         test.offset = sk->min_offset;
2130
2131         ret = btrfs_comp_cpu_keys(key, &test);
2132         if (ret < 0)
2133                 return 0;
2134
2135         test.objectid = sk->max_objectid;
2136         test.type = sk->max_type;
2137         test.offset = sk->max_offset;
2138
2139         ret = btrfs_comp_cpu_keys(key, &test);
2140         if (ret > 0)
2141                 return 0;
2142         return 1;
2143 }
2144
2145 static noinline int copy_to_sk(struct btrfs_path *path,
2146                                struct btrfs_key *key,
2147                                struct btrfs_ioctl_search_key *sk,
2148                                size_t *buf_size,
2149                                char __user *ubuf,
2150                                unsigned long *sk_offset,
2151                                int *num_found)
2152 {
2153         u64 found_transid;
2154         struct extent_buffer *leaf;
2155         struct btrfs_ioctl_search_header sh;
2156         struct btrfs_key test;
2157         unsigned long item_off;
2158         unsigned long item_len;
2159         int nritems;
2160         int i;
2161         int slot;
2162         int ret = 0;
2163
2164         leaf = path->nodes[0];
2165         slot = path->slots[0];
2166         nritems = btrfs_header_nritems(leaf);
2167
2168         if (btrfs_header_generation(leaf) > sk->max_transid) {
2169                 i = nritems;
2170                 goto advance_key;
2171         }
2172         found_transid = btrfs_header_generation(leaf);
2173
2174         for (i = slot; i < nritems; i++) {
2175                 item_off = btrfs_item_ptr_offset(leaf, i);
2176                 item_len = btrfs_item_size(leaf, i);
2177
2178                 btrfs_item_key_to_cpu(leaf, key, i);
2179                 if (!key_in_sk(key, sk))
2180                         continue;
2181
2182                 if (sizeof(sh) + item_len > *buf_size) {
2183                         if (*num_found) {
2184                                 ret = 1;
2185                                 goto out;
2186                         }
2187
2188                         /*
2189                          * return one empty item back for v1, which does not
2190                          * handle -EOVERFLOW
2191                          */
2192
2193                         *buf_size = sizeof(sh) + item_len;
2194                         item_len = 0;
2195                         ret = -EOVERFLOW;
2196                 }
2197
2198                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2199                         ret = 1;
2200                         goto out;
2201                 }
2202
2203                 sh.objectid = key->objectid;
2204                 sh.offset = key->offset;
2205                 sh.type = key->type;
2206                 sh.len = item_len;
2207                 sh.transid = found_transid;
2208
2209                 /*
2210                  * Copy search result header. If we fault then loop again so we
2211                  * can fault in the pages and -EFAULT there if there's a
2212                  * problem. Otherwise we'll fault and then copy the buffer in
2213                  * properly this next time through
2214                  */
2215                 if (copy_to_user_nofault(ubuf + *sk_offset, &sh, sizeof(sh))) {
2216                         ret = 0;
2217                         goto out;
2218                 }
2219
2220                 *sk_offset += sizeof(sh);
2221
2222                 if (item_len) {
2223                         char __user *up = ubuf + *sk_offset;
2224                         /*
2225                          * Copy the item, same behavior as above, but reset the
2226                          * * sk_offset so we copy the full thing again.
2227                          */
2228                         if (read_extent_buffer_to_user_nofault(leaf, up,
2229                                                 item_off, item_len)) {
2230                                 ret = 0;
2231                                 *sk_offset -= sizeof(sh);
2232                                 goto out;
2233                         }
2234
2235                         *sk_offset += item_len;
2236                 }
2237                 (*num_found)++;
2238
2239                 if (ret) /* -EOVERFLOW from above */
2240                         goto out;
2241
2242                 if (*num_found >= sk->nr_items) {
2243                         ret = 1;
2244                         goto out;
2245                 }
2246         }
2247 advance_key:
2248         ret = 0;
2249         test.objectid = sk->max_objectid;
2250         test.type = sk->max_type;
2251         test.offset = sk->max_offset;
2252         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2253                 ret = 1;
2254         else if (key->offset < (u64)-1)
2255                 key->offset++;
2256         else if (key->type < (u8)-1) {
2257                 key->offset = 0;
2258                 key->type++;
2259         } else if (key->objectid < (u64)-1) {
2260                 key->offset = 0;
2261                 key->type = 0;
2262                 key->objectid++;
2263         } else
2264                 ret = 1;
2265 out:
2266         /*
2267          *  0: all items from this leaf copied, continue with next
2268          *  1: * more items can be copied, but unused buffer is too small
2269          *     * all items were found
2270          *     Either way, it will stops the loop which iterates to the next
2271          *     leaf
2272          *  -EOVERFLOW: item was to large for buffer
2273          *  -EFAULT: could not copy extent buffer back to userspace
2274          */
2275         return ret;
2276 }
2277
2278 static noinline int search_ioctl(struct inode *inode,
2279                                  struct btrfs_ioctl_search_key *sk,
2280                                  size_t *buf_size,
2281                                  char __user *ubuf)
2282 {
2283         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2284         struct btrfs_root *root;
2285         struct btrfs_key key;
2286         struct btrfs_path *path;
2287         int ret;
2288         int num_found = 0;
2289         unsigned long sk_offset = 0;
2290
2291         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2292                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2293                 return -EOVERFLOW;
2294         }
2295
2296         path = btrfs_alloc_path();
2297         if (!path)
2298                 return -ENOMEM;
2299
2300         if (sk->tree_id == 0) {
2301                 /* search the root of the inode that was passed */
2302                 root = btrfs_grab_root(BTRFS_I(inode)->root);
2303         } else {
2304                 root = btrfs_get_fs_root(info, sk->tree_id, true);
2305                 if (IS_ERR(root)) {
2306                         btrfs_free_path(path);
2307                         return PTR_ERR(root);
2308                 }
2309         }
2310
2311         key.objectid = sk->min_objectid;
2312         key.type = sk->min_type;
2313         key.offset = sk->min_offset;
2314
2315         while (1) {
2316                 ret = -EFAULT;
2317                 if (fault_in_writeable(ubuf + sk_offset, *buf_size - sk_offset))
2318                         break;
2319
2320                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2321                 if (ret != 0) {
2322                         if (ret > 0)
2323                                 ret = 0;
2324                         goto err;
2325                 }
2326                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2327                                  &sk_offset, &num_found);
2328                 btrfs_release_path(path);
2329                 if (ret)
2330                         break;
2331
2332         }
2333         if (ret > 0)
2334                 ret = 0;
2335 err:
2336         sk->nr_items = num_found;
2337         btrfs_put_root(root);
2338         btrfs_free_path(path);
2339         return ret;
2340 }
2341
2342 static noinline int btrfs_ioctl_tree_search(struct file *file,
2343                                            void __user *argp)
2344 {
2345         struct btrfs_ioctl_search_args __user *uargs;
2346         struct btrfs_ioctl_search_key sk;
2347         struct inode *inode;
2348         int ret;
2349         size_t buf_size;
2350
2351         if (!capable(CAP_SYS_ADMIN))
2352                 return -EPERM;
2353
2354         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2355
2356         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2357                 return -EFAULT;
2358
2359         buf_size = sizeof(uargs->buf);
2360
2361         inode = file_inode(file);
2362         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2363
2364         /*
2365          * In the origin implementation an overflow is handled by returning a
2366          * search header with a len of zero, so reset ret.
2367          */
2368         if (ret == -EOVERFLOW)
2369                 ret = 0;
2370
2371         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2372                 ret = -EFAULT;
2373         return ret;
2374 }
2375
2376 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2377                                                void __user *argp)
2378 {
2379         struct btrfs_ioctl_search_args_v2 __user *uarg;
2380         struct btrfs_ioctl_search_args_v2 args;
2381         struct inode *inode;
2382         int ret;
2383         size_t buf_size;
2384         const size_t buf_limit = SZ_16M;
2385
2386         if (!capable(CAP_SYS_ADMIN))
2387                 return -EPERM;
2388
2389         /* copy search header and buffer size */
2390         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2391         if (copy_from_user(&args, uarg, sizeof(args)))
2392                 return -EFAULT;
2393
2394         buf_size = args.buf_size;
2395
2396         /* limit result size to 16MB */
2397         if (buf_size > buf_limit)
2398                 buf_size = buf_limit;
2399
2400         inode = file_inode(file);
2401         ret = search_ioctl(inode, &args.key, &buf_size,
2402                            (char __user *)(&uarg->buf[0]));
2403         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2404                 ret = -EFAULT;
2405         else if (ret == -EOVERFLOW &&
2406                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2407                 ret = -EFAULT;
2408
2409         return ret;
2410 }
2411
2412 /*
2413  * Search INODE_REFs to identify path name of 'dirid' directory
2414  * in a 'tree_id' tree. and sets path name to 'name'.
2415  */
2416 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2417                                 u64 tree_id, u64 dirid, char *name)
2418 {
2419         struct btrfs_root *root;
2420         struct btrfs_key key;
2421         char *ptr;
2422         int ret = -1;
2423         int slot;
2424         int len;
2425         int total_len = 0;
2426         struct btrfs_inode_ref *iref;
2427         struct extent_buffer *l;
2428         struct btrfs_path *path;
2429
2430         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2431                 name[0]='\0';
2432                 return 0;
2433         }
2434
2435         path = btrfs_alloc_path();
2436         if (!path)
2437                 return -ENOMEM;
2438
2439         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2440
2441         root = btrfs_get_fs_root(info, tree_id, true);
2442         if (IS_ERR(root)) {
2443                 ret = PTR_ERR(root);
2444                 root = NULL;
2445                 goto out;
2446         }
2447
2448         key.objectid = dirid;
2449         key.type = BTRFS_INODE_REF_KEY;
2450         key.offset = (u64)-1;
2451
2452         while (1) {
2453                 ret = btrfs_search_backwards(root, &key, path);
2454                 if (ret < 0)
2455                         goto out;
2456                 else if (ret > 0) {
2457                         ret = -ENOENT;
2458                         goto out;
2459                 }
2460
2461                 l = path->nodes[0];
2462                 slot = path->slots[0];
2463
2464                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2465                 len = btrfs_inode_ref_name_len(l, iref);
2466                 ptr -= len + 1;
2467                 total_len += len + 1;
2468                 if (ptr < name) {
2469                         ret = -ENAMETOOLONG;
2470                         goto out;
2471                 }
2472
2473                 *(ptr + len) = '/';
2474                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2475
2476                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2477                         break;
2478
2479                 btrfs_release_path(path);
2480                 key.objectid = key.offset;
2481                 key.offset = (u64)-1;
2482                 dirid = key.objectid;
2483         }
2484         memmove(name, ptr, total_len);
2485         name[total_len] = '\0';
2486         ret = 0;
2487 out:
2488         btrfs_put_root(root);
2489         btrfs_free_path(path);
2490         return ret;
2491 }
2492
2493 static int btrfs_search_path_in_tree_user(struct user_namespace *mnt_userns,
2494                                 struct inode *inode,
2495                                 struct btrfs_ioctl_ino_lookup_user_args *args)
2496 {
2497         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2498         struct super_block *sb = inode->i_sb;
2499         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2500         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2501         u64 dirid = args->dirid;
2502         unsigned long item_off;
2503         unsigned long item_len;
2504         struct btrfs_inode_ref *iref;
2505         struct btrfs_root_ref *rref;
2506         struct btrfs_root *root = NULL;
2507         struct btrfs_path *path;
2508         struct btrfs_key key, key2;
2509         struct extent_buffer *leaf;
2510         struct inode *temp_inode;
2511         char *ptr;
2512         int slot;
2513         int len;
2514         int total_len = 0;
2515         int ret;
2516
2517         path = btrfs_alloc_path();
2518         if (!path)
2519                 return -ENOMEM;
2520
2521         /*
2522          * If the bottom subvolume does not exist directly under upper_limit,
2523          * construct the path in from the bottom up.
2524          */
2525         if (dirid != upper_limit.objectid) {
2526                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2527
2528                 root = btrfs_get_fs_root(fs_info, treeid, true);
2529                 if (IS_ERR(root)) {
2530                         ret = PTR_ERR(root);
2531                         goto out;
2532                 }
2533
2534                 key.objectid = dirid;
2535                 key.type = BTRFS_INODE_REF_KEY;
2536                 key.offset = (u64)-1;
2537                 while (1) {
2538                         ret = btrfs_search_backwards(root, &key, path);
2539                         if (ret < 0)
2540                                 goto out_put;
2541                         else if (ret > 0) {
2542                                 ret = -ENOENT;
2543                                 goto out_put;
2544                         }
2545
2546                         leaf = path->nodes[0];
2547                         slot = path->slots[0];
2548
2549                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2550                         len = btrfs_inode_ref_name_len(leaf, iref);
2551                         ptr -= len + 1;
2552                         total_len += len + 1;
2553                         if (ptr < args->path) {
2554                                 ret = -ENAMETOOLONG;
2555                                 goto out_put;
2556                         }
2557
2558                         *(ptr + len) = '/';
2559                         read_extent_buffer(leaf, ptr,
2560                                         (unsigned long)(iref + 1), len);
2561
2562                         /* Check the read+exec permission of this directory */
2563                         ret = btrfs_previous_item(root, path, dirid,
2564                                                   BTRFS_INODE_ITEM_KEY);
2565                         if (ret < 0) {
2566                                 goto out_put;
2567                         } else if (ret > 0) {
2568                                 ret = -ENOENT;
2569                                 goto out_put;
2570                         }
2571
2572                         leaf = path->nodes[0];
2573                         slot = path->slots[0];
2574                         btrfs_item_key_to_cpu(leaf, &key2, slot);
2575                         if (key2.objectid != dirid) {
2576                                 ret = -ENOENT;
2577                                 goto out_put;
2578                         }
2579
2580                         temp_inode = btrfs_iget(sb, key2.objectid, root);
2581                         if (IS_ERR(temp_inode)) {
2582                                 ret = PTR_ERR(temp_inode);
2583                                 goto out_put;
2584                         }
2585                         ret = inode_permission(mnt_userns, temp_inode,
2586                                                MAY_READ | MAY_EXEC);
2587                         iput(temp_inode);
2588                         if (ret) {
2589                                 ret = -EACCES;
2590                                 goto out_put;
2591                         }
2592
2593                         if (key.offset == upper_limit.objectid)
2594                                 break;
2595                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2596                                 ret = -EACCES;
2597                                 goto out_put;
2598                         }
2599
2600                         btrfs_release_path(path);
2601                         key.objectid = key.offset;
2602                         key.offset = (u64)-1;
2603                         dirid = key.objectid;
2604                 }
2605
2606                 memmove(args->path, ptr, total_len);
2607                 args->path[total_len] = '\0';
2608                 btrfs_put_root(root);
2609                 root = NULL;
2610                 btrfs_release_path(path);
2611         }
2612
2613         /* Get the bottom subvolume's name from ROOT_REF */
2614         key.objectid = treeid;
2615         key.type = BTRFS_ROOT_REF_KEY;
2616         key.offset = args->treeid;
2617         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2618         if (ret < 0) {
2619                 goto out;
2620         } else if (ret > 0) {
2621                 ret = -ENOENT;
2622                 goto out;
2623         }
2624
2625         leaf = path->nodes[0];
2626         slot = path->slots[0];
2627         btrfs_item_key_to_cpu(leaf, &key, slot);
2628
2629         item_off = btrfs_item_ptr_offset(leaf, slot);
2630         item_len = btrfs_item_size(leaf, slot);
2631         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2632         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2633         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2634                 ret = -EINVAL;
2635                 goto out;
2636         }
2637
2638         /* Copy subvolume's name */
2639         item_off += sizeof(struct btrfs_root_ref);
2640         item_len -= sizeof(struct btrfs_root_ref);
2641         read_extent_buffer(leaf, args->name, item_off, item_len);
2642         args->name[item_len] = 0;
2643
2644 out_put:
2645         btrfs_put_root(root);
2646 out:
2647         btrfs_free_path(path);
2648         return ret;
2649 }
2650
2651 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2652                                            void __user *argp)
2653 {
2654         struct btrfs_ioctl_ino_lookup_args *args;
2655         struct inode *inode;
2656         int ret = 0;
2657
2658         args = memdup_user(argp, sizeof(*args));
2659         if (IS_ERR(args))
2660                 return PTR_ERR(args);
2661
2662         inode = file_inode(file);
2663
2664         /*
2665          * Unprivileged query to obtain the containing subvolume root id. The
2666          * path is reset so it's consistent with btrfs_search_path_in_tree.
2667          */
2668         if (args->treeid == 0)
2669                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2670
2671         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2672                 args->name[0] = 0;
2673                 goto out;
2674         }
2675
2676         if (!capable(CAP_SYS_ADMIN)) {
2677                 ret = -EPERM;
2678                 goto out;
2679         }
2680
2681         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2682                                         args->treeid, args->objectid,
2683                                         args->name);
2684
2685 out:
2686         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2687                 ret = -EFAULT;
2688
2689         kfree(args);
2690         return ret;
2691 }
2692
2693 /*
2694  * Version of ino_lookup ioctl (unprivileged)
2695  *
2696  * The main differences from ino_lookup ioctl are:
2697  *
2698  *   1. Read + Exec permission will be checked using inode_permission() during
2699  *      path construction. -EACCES will be returned in case of failure.
2700  *   2. Path construction will be stopped at the inode number which corresponds
2701  *      to the fd with which this ioctl is called. If constructed path does not
2702  *      exist under fd's inode, -EACCES will be returned.
2703  *   3. The name of bottom subvolume is also searched and filled.
2704  */
2705 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2706 {
2707         struct btrfs_ioctl_ino_lookup_user_args *args;
2708         struct inode *inode;
2709         int ret;
2710
2711         args = memdup_user(argp, sizeof(*args));
2712         if (IS_ERR(args))
2713                 return PTR_ERR(args);
2714
2715         inode = file_inode(file);
2716
2717         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2718             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2719                 /*
2720                  * The subvolume does not exist under fd with which this is
2721                  * called
2722                  */
2723                 kfree(args);
2724                 return -EACCES;
2725         }
2726
2727         ret = btrfs_search_path_in_tree_user(file_mnt_user_ns(file), inode, args);
2728
2729         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2730                 ret = -EFAULT;
2731
2732         kfree(args);
2733         return ret;
2734 }
2735
2736 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2737 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2738 {
2739         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2740         struct btrfs_fs_info *fs_info;
2741         struct btrfs_root *root;
2742         struct btrfs_path *path;
2743         struct btrfs_key key;
2744         struct btrfs_root_item *root_item;
2745         struct btrfs_root_ref *rref;
2746         struct extent_buffer *leaf;
2747         unsigned long item_off;
2748         unsigned long item_len;
2749         struct inode *inode;
2750         int slot;
2751         int ret = 0;
2752
2753         path = btrfs_alloc_path();
2754         if (!path)
2755                 return -ENOMEM;
2756
2757         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2758         if (!subvol_info) {
2759                 btrfs_free_path(path);
2760                 return -ENOMEM;
2761         }
2762
2763         inode = file_inode(file);
2764         fs_info = BTRFS_I(inode)->root->fs_info;
2765
2766         /* Get root_item of inode's subvolume */
2767         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2768         root = btrfs_get_fs_root(fs_info, key.objectid, true);
2769         if (IS_ERR(root)) {
2770                 ret = PTR_ERR(root);
2771                 goto out_free;
2772         }
2773         root_item = &root->root_item;
2774
2775         subvol_info->treeid = key.objectid;
2776
2777         subvol_info->generation = btrfs_root_generation(root_item);
2778         subvol_info->flags = btrfs_root_flags(root_item);
2779
2780         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2781         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2782                                                     BTRFS_UUID_SIZE);
2783         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2784                                                     BTRFS_UUID_SIZE);
2785
2786         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2787         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2788         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2789
2790         subvol_info->otransid = btrfs_root_otransid(root_item);
2791         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2792         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2793
2794         subvol_info->stransid = btrfs_root_stransid(root_item);
2795         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2796         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2797
2798         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2799         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2800         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2801
2802         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2803                 /* Search root tree for ROOT_BACKREF of this subvolume */
2804                 key.type = BTRFS_ROOT_BACKREF_KEY;
2805                 key.offset = 0;
2806                 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2807                 if (ret < 0) {
2808                         goto out;
2809                 } else if (path->slots[0] >=
2810                            btrfs_header_nritems(path->nodes[0])) {
2811                         ret = btrfs_next_leaf(fs_info->tree_root, path);
2812                         if (ret < 0) {
2813                                 goto out;
2814                         } else if (ret > 0) {
2815                                 ret = -EUCLEAN;
2816                                 goto out;
2817                         }
2818                 }
2819
2820                 leaf = path->nodes[0];
2821                 slot = path->slots[0];
2822                 btrfs_item_key_to_cpu(leaf, &key, slot);
2823                 if (key.objectid == subvol_info->treeid &&
2824                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2825                         subvol_info->parent_id = key.offset;
2826
2827                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2828                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2829
2830                         item_off = btrfs_item_ptr_offset(leaf, slot)
2831                                         + sizeof(struct btrfs_root_ref);
2832                         item_len = btrfs_item_size(leaf, slot)
2833                                         - sizeof(struct btrfs_root_ref);
2834                         read_extent_buffer(leaf, subvol_info->name,
2835                                            item_off, item_len);
2836                 } else {
2837                         ret = -ENOENT;
2838                         goto out;
2839                 }
2840         }
2841
2842         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2843                 ret = -EFAULT;
2844
2845 out:
2846         btrfs_put_root(root);
2847 out_free:
2848         btrfs_free_path(path);
2849         kfree(subvol_info);
2850         return ret;
2851 }
2852
2853 /*
2854  * Return ROOT_REF information of the subvolume containing this inode
2855  * except the subvolume name.
2856  */
2857 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2858 {
2859         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2860         struct btrfs_root_ref *rref;
2861         struct btrfs_root *root;
2862         struct btrfs_path *path;
2863         struct btrfs_key key;
2864         struct extent_buffer *leaf;
2865         struct inode *inode;
2866         u64 objectid;
2867         int slot;
2868         int ret;
2869         u8 found;
2870
2871         path = btrfs_alloc_path();
2872         if (!path)
2873                 return -ENOMEM;
2874
2875         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2876         if (IS_ERR(rootrefs)) {
2877                 btrfs_free_path(path);
2878                 return PTR_ERR(rootrefs);
2879         }
2880
2881         inode = file_inode(file);
2882         root = BTRFS_I(inode)->root->fs_info->tree_root;
2883         objectid = BTRFS_I(inode)->root->root_key.objectid;
2884
2885         key.objectid = objectid;
2886         key.type = BTRFS_ROOT_REF_KEY;
2887         key.offset = rootrefs->min_treeid;
2888         found = 0;
2889
2890         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2891         if (ret < 0) {
2892                 goto out;
2893         } else if (path->slots[0] >=
2894                    btrfs_header_nritems(path->nodes[0])) {
2895                 ret = btrfs_next_leaf(root, path);
2896                 if (ret < 0) {
2897                         goto out;
2898                 } else if (ret > 0) {
2899                         ret = -EUCLEAN;
2900                         goto out;
2901                 }
2902         }
2903         while (1) {
2904                 leaf = path->nodes[0];
2905                 slot = path->slots[0];
2906
2907                 btrfs_item_key_to_cpu(leaf, &key, slot);
2908                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2909                         ret = 0;
2910                         goto out;
2911                 }
2912
2913                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2914                         ret = -EOVERFLOW;
2915                         goto out;
2916                 }
2917
2918                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2919                 rootrefs->rootref[found].treeid = key.offset;
2920                 rootrefs->rootref[found].dirid =
2921                                   btrfs_root_ref_dirid(leaf, rref);
2922                 found++;
2923
2924                 ret = btrfs_next_item(root, path);
2925                 if (ret < 0) {
2926                         goto out;
2927                 } else if (ret > 0) {
2928                         ret = -EUCLEAN;
2929                         goto out;
2930                 }
2931         }
2932
2933 out:
2934         if (!ret || ret == -EOVERFLOW) {
2935                 rootrefs->num_items = found;
2936                 /* update min_treeid for next search */
2937                 if (found)
2938                         rootrefs->min_treeid =
2939                                 rootrefs->rootref[found - 1].treeid + 1;
2940                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2941                         ret = -EFAULT;
2942         }
2943
2944         kfree(rootrefs);
2945         btrfs_free_path(path);
2946
2947         return ret;
2948 }
2949
2950 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2951                                              void __user *arg,
2952                                              bool destroy_v2)
2953 {
2954         struct dentry *parent = file->f_path.dentry;
2955         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2956         struct dentry *dentry;
2957         struct inode *dir = d_inode(parent);
2958         struct inode *inode;
2959         struct btrfs_root *root = BTRFS_I(dir)->root;
2960         struct btrfs_root *dest = NULL;
2961         struct btrfs_ioctl_vol_args *vol_args = NULL;
2962         struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
2963         struct user_namespace *mnt_userns = file_mnt_user_ns(file);
2964         char *subvol_name, *subvol_name_ptr = NULL;
2965         int subvol_namelen;
2966         int err = 0;
2967         bool destroy_parent = false;
2968
2969         if (destroy_v2) {
2970                 vol_args2 = memdup_user(arg, sizeof(*vol_args2));
2971                 if (IS_ERR(vol_args2))
2972                         return PTR_ERR(vol_args2);
2973
2974                 if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
2975                         err = -EOPNOTSUPP;
2976                         goto out;
2977                 }
2978
2979                 /*
2980                  * If SPEC_BY_ID is not set, we are looking for the subvolume by
2981                  * name, same as v1 currently does.
2982                  */
2983                 if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
2984                         vol_args2->name[BTRFS_SUBVOL_NAME_MAX] = 0;
2985                         subvol_name = vol_args2->name;
2986
2987                         err = mnt_want_write_file(file);
2988                         if (err)
2989                                 goto out;
2990                 } else {
2991                         struct inode *old_dir;
2992
2993                         if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
2994                                 err = -EINVAL;
2995                                 goto out;
2996                         }
2997
2998                         err = mnt_want_write_file(file);
2999                         if (err)
3000                                 goto out;
3001
3002                         dentry = btrfs_get_dentry(fs_info->sb,
3003                                         BTRFS_FIRST_FREE_OBJECTID,
3004                                         vol_args2->subvolid, 0, 0);
3005                         if (IS_ERR(dentry)) {
3006                                 err = PTR_ERR(dentry);
3007                                 goto out_drop_write;
3008                         }
3009
3010                         /*
3011                          * Change the default parent since the subvolume being
3012                          * deleted can be outside of the current mount point.
3013                          */
3014                         parent = btrfs_get_parent(dentry);
3015
3016                         /*
3017                          * At this point dentry->d_name can point to '/' if the
3018                          * subvolume we want to destroy is outsite of the
3019                          * current mount point, so we need to release the
3020                          * current dentry and execute the lookup to return a new
3021                          * one with ->d_name pointing to the
3022                          * <mount point>/subvol_name.
3023                          */
3024                         dput(dentry);
3025                         if (IS_ERR(parent)) {
3026                                 err = PTR_ERR(parent);
3027                                 goto out_drop_write;
3028                         }
3029                         old_dir = dir;
3030                         dir = d_inode(parent);
3031
3032                         /*
3033                          * If v2 was used with SPEC_BY_ID, a new parent was
3034                          * allocated since the subvolume can be outside of the
3035                          * current mount point. Later on we need to release this
3036                          * new parent dentry.
3037                          */
3038                         destroy_parent = true;
3039
3040                         /*
3041                          * On idmapped mounts, deletion via subvolid is
3042                          * restricted to subvolumes that are immediate
3043                          * ancestors of the inode referenced by the file
3044                          * descriptor in the ioctl. Otherwise the idmapping
3045                          * could potentially be abused to delete subvolumes
3046                          * anywhere in the filesystem the user wouldn't be able
3047                          * to delete without an idmapped mount.
3048                          */
3049                         if (old_dir != dir && mnt_userns != &init_user_ns) {
3050                                 err = -EOPNOTSUPP;
3051                                 goto free_parent;
3052                         }
3053
3054                         subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
3055                                                 fs_info, vol_args2->subvolid);
3056                         if (IS_ERR(subvol_name_ptr)) {
3057                                 err = PTR_ERR(subvol_name_ptr);
3058                                 goto free_parent;
3059                         }
3060                         /* subvol_name_ptr is already nul terminated */
3061                         subvol_name = (char *)kbasename(subvol_name_ptr);
3062                 }
3063         } else {
3064                 vol_args = memdup_user(arg, sizeof(*vol_args));
3065                 if (IS_ERR(vol_args))
3066                         return PTR_ERR(vol_args);
3067
3068                 vol_args->name[BTRFS_PATH_NAME_MAX] = 0;
3069                 subvol_name = vol_args->name;
3070
3071                 err = mnt_want_write_file(file);
3072                 if (err)
3073                         goto out;
3074         }
3075
3076         subvol_namelen = strlen(subvol_name);
3077
3078         if (strchr(subvol_name, '/') ||
3079             strncmp(subvol_name, "..", subvol_namelen) == 0) {
3080                 err = -EINVAL;
3081                 goto free_subvol_name;
3082         }
3083
3084         if (!S_ISDIR(dir->i_mode)) {
3085                 err = -ENOTDIR;
3086                 goto free_subvol_name;
3087         }
3088
3089         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
3090         if (err == -EINTR)
3091                 goto free_subvol_name;
3092         dentry = lookup_one(mnt_userns, subvol_name, parent, subvol_namelen);
3093         if (IS_ERR(dentry)) {
3094                 err = PTR_ERR(dentry);
3095                 goto out_unlock_dir;
3096         }
3097
3098         if (d_really_is_negative(dentry)) {
3099                 err = -ENOENT;
3100                 goto out_dput;
3101         }
3102
3103         inode = d_inode(dentry);
3104         dest = BTRFS_I(inode)->root;
3105         if (!capable(CAP_SYS_ADMIN)) {
3106                 /*
3107                  * Regular user.  Only allow this with a special mount
3108                  * option, when the user has write+exec access to the
3109                  * subvol root, and when rmdir(2) would have been
3110                  * allowed.
3111                  *
3112                  * Note that this is _not_ check that the subvol is
3113                  * empty or doesn't contain data that we wouldn't
3114                  * otherwise be able to delete.
3115                  *
3116                  * Users who want to delete empty subvols should try
3117                  * rmdir(2).
3118                  */
3119                 err = -EPERM;
3120                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
3121                         goto out_dput;
3122
3123                 /*
3124                  * Do not allow deletion if the parent dir is the same
3125                  * as the dir to be deleted.  That means the ioctl
3126                  * must be called on the dentry referencing the root
3127                  * of the subvol, not a random directory contained
3128                  * within it.
3129                  */
3130                 err = -EINVAL;
3131                 if (root == dest)
3132                         goto out_dput;
3133
3134                 err = inode_permission(mnt_userns, inode, MAY_WRITE | MAY_EXEC);
3135                 if (err)
3136                         goto out_dput;
3137         }
3138
3139         /* check if subvolume may be deleted by a user */
3140         err = btrfs_may_delete(mnt_userns, dir, dentry, 1);
3141         if (err)
3142                 goto out_dput;
3143
3144         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
3145                 err = -EINVAL;
3146                 goto out_dput;
3147         }
3148
3149         btrfs_inode_lock(inode, 0);
3150         err = btrfs_delete_subvolume(dir, dentry);
3151         btrfs_inode_unlock(inode, 0);
3152         if (!err)
3153                 d_delete_notify(dir, dentry);
3154
3155 out_dput:
3156         dput(dentry);
3157 out_unlock_dir:
3158         btrfs_inode_unlock(dir, 0);
3159 free_subvol_name:
3160         kfree(subvol_name_ptr);
3161 free_parent:
3162         if (destroy_parent)
3163                 dput(parent);
3164 out_drop_write:
3165         mnt_drop_write_file(file);
3166 out:
3167         kfree(vol_args2);
3168         kfree(vol_args);
3169         return err;
3170 }
3171
3172 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
3173 {
3174         struct inode *inode = file_inode(file);
3175         struct btrfs_root *root = BTRFS_I(inode)->root;
3176         struct btrfs_ioctl_defrag_range_args range = {0};
3177         int ret;
3178
3179         ret = mnt_want_write_file(file);
3180         if (ret)
3181                 return ret;
3182
3183         if (btrfs_root_readonly(root)) {
3184                 ret = -EROFS;
3185                 goto out;
3186         }
3187
3188         switch (inode->i_mode & S_IFMT) {
3189         case S_IFDIR:
3190                 if (!capable(CAP_SYS_ADMIN)) {
3191                         ret = -EPERM;
3192                         goto out;
3193                 }
3194                 ret = btrfs_defrag_root(root);
3195                 break;
3196         case S_IFREG:
3197                 /*
3198                  * Note that this does not check the file descriptor for write
3199                  * access. This prevents defragmenting executables that are
3200                  * running and allows defrag on files open in read-only mode.
3201                  */
3202                 if (!capable(CAP_SYS_ADMIN) &&
3203                     inode_permission(&init_user_ns, inode, MAY_WRITE)) {
3204                         ret = -EPERM;
3205                         goto out;
3206                 }
3207
3208                 if (argp) {
3209                         if (copy_from_user(&range, argp, sizeof(range))) {
3210                                 ret = -EFAULT;
3211                                 goto out;
3212                         }
3213                         /* compression requires us to start the IO */
3214                         if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
3215                                 range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
3216                                 range.extent_thresh = (u32)-1;
3217                         }
3218                 } else {
3219                         /* the rest are all set to zero by kzalloc */
3220                         range.len = (u64)-1;
3221                 }
3222                 ret = btrfs_defrag_file(file_inode(file), &file->f_ra,
3223                                         &range, BTRFS_OLDEST_GENERATION, 0);
3224                 if (ret > 0)
3225                         ret = 0;
3226                 break;
3227         default:
3228                 ret = -EINVAL;
3229         }
3230 out:
3231         mnt_drop_write_file(file);
3232         return ret;
3233 }
3234
3235 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
3236 {
3237         struct btrfs_ioctl_vol_args *vol_args;
3238         bool restore_op = false;
3239         int ret;
3240
3241         if (!capable(CAP_SYS_ADMIN))
3242                 return -EPERM;
3243
3244         if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD)) {
3245                 if (!btrfs_exclop_start_try_lock(fs_info, BTRFS_EXCLOP_DEV_ADD))
3246                         return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3247
3248                 /*
3249                  * We can do the device add because we have a paused balanced,
3250                  * change the exclusive op type and remember we should bring
3251                  * back the paused balance
3252                  */
3253                 fs_info->exclusive_operation = BTRFS_EXCLOP_DEV_ADD;
3254                 btrfs_exclop_start_unlock(fs_info);
3255                 restore_op = true;
3256         }
3257
3258         vol_args = memdup_user(arg, sizeof(*vol_args));
3259         if (IS_ERR(vol_args)) {
3260                 ret = PTR_ERR(vol_args);
3261                 goto out;
3262         }
3263
3264         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3265         ret = btrfs_init_new_device(fs_info, vol_args->name);
3266
3267         if (!ret)
3268                 btrfs_info(fs_info, "disk added %s", vol_args->name);
3269
3270         kfree(vol_args);
3271 out:
3272         if (restore_op)
3273                 btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED);
3274         else
3275                 btrfs_exclop_finish(fs_info);
3276         return ret;
3277 }
3278
3279 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3280 {
3281         BTRFS_DEV_LOOKUP_ARGS(args);
3282         struct inode *inode = file_inode(file);
3283         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3284         struct btrfs_ioctl_vol_args_v2 *vol_args;
3285         struct block_device *bdev = NULL;
3286         fmode_t mode;
3287         int ret;
3288         bool cancel = false;
3289
3290         if (!capable(CAP_SYS_ADMIN))
3291                 return -EPERM;
3292
3293         vol_args = memdup_user(arg, sizeof(*vol_args));
3294         if (IS_ERR(vol_args))
3295                 return PTR_ERR(vol_args);
3296
3297         if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
3298                 ret = -EOPNOTSUPP;
3299                 goto out;
3300         }
3301
3302         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3303         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3304                 args.devid = vol_args->devid;
3305         } else if (!strcmp("cancel", vol_args->name)) {
3306                 cancel = true;
3307         } else {
3308                 ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
3309                 if (ret)
3310                         goto out;
3311         }
3312
3313         ret = mnt_want_write_file(file);
3314         if (ret)
3315                 goto out;
3316
3317         ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
3318                                            cancel);
3319         if (ret)
3320                 goto err_drop;
3321
3322         /* Exclusive operation is now claimed */
3323         ret = btrfs_rm_device(fs_info, &args, &bdev, &mode);
3324
3325         btrfs_exclop_finish(fs_info);
3326
3327         if (!ret) {
3328                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3329                         btrfs_info(fs_info, "device deleted: id %llu",
3330                                         vol_args->devid);
3331                 else
3332                         btrfs_info(fs_info, "device deleted: %s",
3333                                         vol_args->name);
3334         }
3335 err_drop:
3336         mnt_drop_write_file(file);
3337         if (bdev)
3338                 blkdev_put(bdev, mode);
3339 out:
3340         btrfs_put_dev_args_from_path(&args);
3341         kfree(vol_args);
3342         return ret;
3343 }
3344
3345 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3346 {
3347         BTRFS_DEV_LOOKUP_ARGS(args);
3348         struct inode *inode = file_inode(file);
3349         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3350         struct btrfs_ioctl_vol_args *vol_args;
3351         struct block_device *bdev = NULL;
3352         fmode_t mode;
3353         int ret;
3354         bool cancel = false;
3355
3356         if (!capable(CAP_SYS_ADMIN))
3357                 return -EPERM;
3358
3359         vol_args = memdup_user(arg, sizeof(*vol_args));
3360         if (IS_ERR(vol_args))
3361                 return PTR_ERR(vol_args);
3362
3363         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3364         if (!strcmp("cancel", vol_args->name)) {
3365                 cancel = true;
3366         } else {
3367                 ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
3368                 if (ret)
3369                         goto out;
3370         }
3371
3372         ret = mnt_want_write_file(file);
3373         if (ret)
3374                 goto out;
3375
3376         ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
3377                                            cancel);
3378         if (ret == 0) {
3379                 ret = btrfs_rm_device(fs_info, &args, &bdev, &mode);
3380                 if (!ret)
3381                         btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3382                 btrfs_exclop_finish(fs_info);
3383         }
3384
3385         mnt_drop_write_file(file);
3386         if (bdev)
3387                 blkdev_put(bdev, mode);
3388 out:
3389         btrfs_put_dev_args_from_path(&args);
3390         kfree(vol_args);
3391         return ret;
3392 }
3393
3394 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3395                                 void __user *arg)
3396 {
3397         struct btrfs_ioctl_fs_info_args *fi_args;
3398         struct btrfs_device *device;
3399         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3400         u64 flags_in;
3401         int ret = 0;
3402
3403         fi_args = memdup_user(arg, sizeof(*fi_args));
3404         if (IS_ERR(fi_args))
3405                 return PTR_ERR(fi_args);
3406
3407         flags_in = fi_args->flags;
3408         memset(fi_args, 0, sizeof(*fi_args));
3409
3410         rcu_read_lock();
3411         fi_args->num_devices = fs_devices->num_devices;
3412
3413         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3414                 if (device->devid > fi_args->max_id)
3415                         fi_args->max_id = device->devid;
3416         }
3417         rcu_read_unlock();
3418
3419         memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
3420         fi_args->nodesize = fs_info->nodesize;
3421         fi_args->sectorsize = fs_info->sectorsize;
3422         fi_args->clone_alignment = fs_info->sectorsize;
3423
3424         if (flags_in & BTRFS_FS_INFO_FLAG_CSUM_INFO) {
3425                 fi_args->csum_type = btrfs_super_csum_type(fs_info->super_copy);
3426                 fi_args->csum_size = btrfs_super_csum_size(fs_info->super_copy);
3427                 fi_args->flags |= BTRFS_FS_INFO_FLAG_CSUM_INFO;
3428         }
3429
3430         if (flags_in & BTRFS_FS_INFO_FLAG_GENERATION) {
3431                 fi_args->generation = fs_info->generation;
3432                 fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;
3433         }
3434
3435         if (flags_in & BTRFS_FS_INFO_FLAG_METADATA_UUID) {
3436                 memcpy(&fi_args->metadata_uuid, fs_devices->metadata_uuid,
3437                        sizeof(fi_args->metadata_uuid));
3438                 fi_args->flags |= BTRFS_FS_INFO_FLAG_METADATA_UUID;
3439         }
3440
3441         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3442                 ret = -EFAULT;
3443
3444         kfree(fi_args);
3445         return ret;
3446 }
3447
3448 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3449                                  void __user *arg)
3450 {
3451         BTRFS_DEV_LOOKUP_ARGS(args);
3452         struct btrfs_ioctl_dev_info_args *di_args;
3453         struct btrfs_device *dev;
3454         int ret = 0;
3455
3456         di_args = memdup_user(arg, sizeof(*di_args));
3457         if (IS_ERR(di_args))
3458                 return PTR_ERR(di_args);
3459
3460         args.devid = di_args->devid;
3461         if (!btrfs_is_empty_uuid(di_args->uuid))
3462                 args.uuid = di_args->uuid;
3463
3464         rcu_read_lock();
3465         dev = btrfs_find_device(fs_info->fs_devices, &args);
3466         if (!dev) {
3467                 ret = -ENODEV;
3468                 goto out;
3469         }
3470
3471         di_args->devid = dev->devid;
3472         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3473         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3474         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3475         if (dev->name) {
3476                 strncpy(di_args->path, rcu_str_deref(dev->name),
3477                                 sizeof(di_args->path) - 1);
3478                 di_args->path[sizeof(di_args->path) - 1] = 0;
3479         } else {
3480                 di_args->path[0] = '\0';
3481         }
3482
3483 out:
3484         rcu_read_unlock();
3485         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3486                 ret = -EFAULT;
3487
3488         kfree(di_args);
3489         return ret;
3490 }
3491
3492 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3493 {
3494         struct inode *inode = file_inode(file);
3495         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3496         struct btrfs_root *root = BTRFS_I(inode)->root;
3497         struct btrfs_root *new_root;
3498         struct btrfs_dir_item *di;
3499         struct btrfs_trans_handle *trans;
3500         struct btrfs_path *path = NULL;
3501         struct btrfs_disk_key disk_key;
3502         u64 objectid = 0;
3503         u64 dir_id;
3504         int ret;
3505
3506         if (!capable(CAP_SYS_ADMIN))
3507                 return -EPERM;
3508
3509         ret = mnt_want_write_file(file);
3510         if (ret)
3511                 return ret;
3512
3513         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3514                 ret = -EFAULT;
3515                 goto out;
3516         }
3517
3518         if (!objectid)
3519                 objectid = BTRFS_FS_TREE_OBJECTID;
3520
3521         new_root = btrfs_get_fs_root(fs_info, objectid, true);
3522         if (IS_ERR(new_root)) {
3523                 ret = PTR_ERR(new_root);
3524                 goto out;
3525         }
3526         if (!is_fstree(new_root->root_key.objectid)) {
3527                 ret = -ENOENT;
3528                 goto out_free;
3529         }
3530
3531         path = btrfs_alloc_path();
3532         if (!path) {
3533                 ret = -ENOMEM;
3534                 goto out_free;
3535         }
3536
3537         trans = btrfs_start_transaction(root, 1);
3538         if (IS_ERR(trans)) {
3539                 ret = PTR_ERR(trans);
3540                 goto out_free;
3541         }
3542
3543         dir_id = btrfs_super_root_dir(fs_info->super_copy);
3544         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
3545                                    dir_id, "default", 7, 1);
3546         if (IS_ERR_OR_NULL(di)) {
3547                 btrfs_release_path(path);
3548                 btrfs_end_transaction(trans);
3549                 btrfs_err(fs_info,
3550                           "Umm, you don't have the default diritem, this isn't going to work");
3551                 ret = -ENOENT;
3552                 goto out_free;
3553         }
3554
3555         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3556         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3557         btrfs_mark_buffer_dirty(path->nodes[0]);
3558         btrfs_release_path(path);
3559
3560         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
3561         btrfs_end_transaction(trans);
3562 out_free:
3563         btrfs_put_root(new_root);
3564         btrfs_free_path(path);
3565 out:
3566         mnt_drop_write_file(file);
3567         return ret;
3568 }
3569
3570 static void get_block_group_info(struct list_head *groups_list,
3571                                  struct btrfs_ioctl_space_info *space)
3572 {
3573         struct btrfs_block_group *block_group;
3574
3575         space->total_bytes = 0;
3576         space->used_bytes = 0;
3577         space->flags = 0;
3578         list_for_each_entry(block_group, groups_list, list) {
3579                 space->flags = block_group->flags;
3580                 space->total_bytes += block_group->length;
3581                 space->used_bytes += block_group->used;
3582         }
3583 }
3584
3585 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
3586                                    void __user *arg)
3587 {
3588         struct btrfs_ioctl_space_args space_args;
3589         struct btrfs_ioctl_space_info space;
3590         struct btrfs_ioctl_space_info *dest;
3591         struct btrfs_ioctl_space_info *dest_orig;
3592         struct btrfs_ioctl_space_info __user *user_dest;
3593         struct btrfs_space_info *info;
3594         static const u64 types[] = {
3595                 BTRFS_BLOCK_GROUP_DATA,
3596                 BTRFS_BLOCK_GROUP_SYSTEM,
3597                 BTRFS_BLOCK_GROUP_METADATA,
3598                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
3599         };
3600         int num_types = 4;
3601         int alloc_size;
3602         int ret = 0;
3603         u64 slot_count = 0;
3604         int i, c;
3605
3606         if (copy_from_user(&space_args,
3607                            (struct btrfs_ioctl_space_args __user *)arg,
3608                            sizeof(space_args)))
3609                 return -EFAULT;
3610
3611         for (i = 0; i < num_types; i++) {
3612                 struct btrfs_space_info *tmp;
3613
3614                 info = NULL;
3615                 list_for_each_entry(tmp, &fs_info->space_info, list) {
3616                         if (tmp->flags == types[i]) {
3617                                 info = tmp;
3618                                 break;
3619                         }
3620                 }
3621
3622                 if (!info)
3623                         continue;
3624
3625                 down_read(&info->groups_sem);
3626                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3627                         if (!list_empty(&info->block_groups[c]))
3628                                 slot_count++;
3629                 }
3630                 up_read(&info->groups_sem);
3631         }
3632
3633         /*
3634          * Global block reserve, exported as a space_info
3635          */
3636         slot_count++;
3637
3638         /* space_slots == 0 means they are asking for a count */
3639         if (space_args.space_slots == 0) {
3640                 space_args.total_spaces = slot_count;
3641                 goto out;
3642         }
3643
3644         slot_count = min_t(u64, space_args.space_slots, slot_count);
3645
3646         alloc_size = sizeof(*dest) * slot_count;
3647
3648         /* we generally have at most 6 or so space infos, one for each raid
3649          * level.  So, a whole page should be more than enough for everyone
3650          */
3651         if (alloc_size > PAGE_SIZE)
3652                 return -ENOMEM;
3653
3654         space_args.total_spaces = 0;
3655         dest = kmalloc(alloc_size, GFP_KERNEL);
3656         if (!dest)
3657                 return -ENOMEM;
3658         dest_orig = dest;
3659
3660         /* now we have a buffer to copy into */
3661         for (i = 0; i < num_types; i++) {
3662                 struct btrfs_space_info *tmp;
3663
3664                 if (!slot_count)
3665                         break;
3666
3667                 info = NULL;
3668                 list_for_each_entry(tmp, &fs_info->space_info, list) {
3669                         if (tmp->flags == types[i]) {
3670                                 info = tmp;
3671                                 break;
3672                         }
3673                 }
3674
3675                 if (!info)
3676                         continue;
3677                 down_read(&info->groups_sem);
3678                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3679                         if (!list_empty(&info->block_groups[c])) {
3680                                 get_block_group_info(&info->block_groups[c],
3681                                                      &space);
3682                                 memcpy(dest, &space, sizeof(space));
3683                                 dest++;
3684                                 space_args.total_spaces++;
3685                                 slot_count--;
3686                         }
3687                         if (!slot_count)
3688                                 break;
3689                 }
3690                 up_read(&info->groups_sem);
3691         }
3692
3693         /*
3694          * Add global block reserve
3695          */
3696         if (slot_count) {
3697                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3698
3699                 spin_lock(&block_rsv->lock);
3700                 space.total_bytes = block_rsv->size;
3701                 space.used_bytes = block_rsv->size - block_rsv->reserved;
3702                 spin_unlock(&block_rsv->lock);
3703                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3704                 memcpy(dest, &space, sizeof(space));
3705                 space_args.total_spaces++;
3706         }
3707
3708         user_dest = (struct btrfs_ioctl_space_info __user *)
3709                 (arg + sizeof(struct btrfs_ioctl_space_args));
3710
3711         if (copy_to_user(user_dest, dest_orig, alloc_size))
3712                 ret = -EFAULT;
3713
3714         kfree(dest_orig);
3715 out:
3716         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3717                 ret = -EFAULT;
3718
3719         return ret;
3720 }
3721
3722 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3723                                             void __user *argp)
3724 {
3725         struct btrfs_trans_handle *trans;
3726         u64 transid;
3727
3728         trans = btrfs_attach_transaction_barrier(root);
3729         if (IS_ERR(trans)) {
3730                 if (PTR_ERR(trans) != -ENOENT)
3731                         return PTR_ERR(trans);
3732
3733                 /* No running transaction, don't bother */
3734                 transid = root->fs_info->last_trans_committed;
3735                 goto out;
3736         }
3737         transid = trans->transid;
3738         btrfs_commit_transaction_async(trans);
3739 out:
3740         if (argp)
3741                 if (copy_to_user(argp, &transid, sizeof(transid)))
3742                         return -EFAULT;
3743         return 0;
3744 }
3745
3746 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
3747                                            void __user *argp)
3748 {
3749         u64 transid;
3750
3751         if (argp) {
3752                 if (copy_from_user(&transid, argp, sizeof(transid)))
3753                         return -EFAULT;
3754         } else {
3755                 transid = 0;  /* current trans */
3756         }
3757         return btrfs_wait_for_commit(fs_info, transid);
3758 }
3759
3760 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3761 {
3762         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
3763         struct btrfs_ioctl_scrub_args *sa;
3764         int ret;
3765
3766         if (!capable(CAP_SYS_ADMIN))
3767                 return -EPERM;
3768
3769         sa = memdup_user(arg, sizeof(*sa));
3770         if (IS_ERR(sa))
3771                 return PTR_ERR(sa);
3772
3773         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3774                 ret = mnt_want_write_file(file);
3775                 if (ret)
3776                         goto out;
3777         }
3778
3779         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
3780                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3781                               0);
3782
3783         /*
3784          * Copy scrub args to user space even if btrfs_scrub_dev() returned an
3785          * error. This is important as it allows user space to know how much
3786          * progress scrub has done. For example, if scrub is canceled we get
3787          * -ECANCELED from btrfs_scrub_dev() and return that error back to user
3788          * space. Later user space can inspect the progress from the structure
3789          * btrfs_ioctl_scrub_args and resume scrub from where it left off
3790          * previously (btrfs-progs does this).
3791          * If we fail to copy the btrfs_ioctl_scrub_args structure to user space
3792          * then return -EFAULT to signal the structure was not copied or it may
3793          * be corrupt and unreliable due to a partial copy.
3794          */
3795         if (copy_to_user(arg, sa, sizeof(*sa)))
3796                 ret = -EFAULT;
3797
3798         if (!(sa->flags & BTRFS_SCRUB_READONLY))
3799                 mnt_drop_write_file(file);
3800 out:
3801         kfree(sa);
3802         return ret;
3803 }
3804
3805 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
3806 {
3807         if (!capable(CAP_SYS_ADMIN))
3808                 return -EPERM;
3809
3810         return btrfs_scrub_cancel(fs_info);
3811 }
3812
3813 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
3814                                        void __user *arg)
3815 {
3816         struct btrfs_ioctl_scrub_args *sa;
3817         int ret;
3818
3819         if (!capable(CAP_SYS_ADMIN))
3820                 return -EPERM;
3821
3822         sa = memdup_user(arg, sizeof(*sa));
3823         if (IS_ERR(sa))
3824                 return PTR_ERR(sa);
3825
3826         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
3827
3828         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3829                 ret = -EFAULT;
3830
3831         kfree(sa);
3832         return ret;
3833 }
3834
3835 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
3836                                       void __user *arg)
3837 {
3838         struct btrfs_ioctl_get_dev_stats *sa;
3839         int ret;
3840
3841         sa = memdup_user(arg, sizeof(*sa));
3842         if (IS_ERR(sa))
3843                 return PTR_ERR(sa);
3844
3845         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3846                 kfree(sa);
3847                 return -EPERM;
3848         }
3849
3850         ret = btrfs_get_dev_stats(fs_info, sa);
3851
3852         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3853                 ret = -EFAULT;
3854
3855         kfree(sa);
3856         return ret;
3857 }
3858
3859 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
3860                                     void __user *arg)
3861 {
3862         struct btrfs_ioctl_dev_replace_args *p;
3863         int ret;
3864
3865         if (!capable(CAP_SYS_ADMIN))
3866                 return -EPERM;
3867
3868         p = memdup_user(arg, sizeof(*p));
3869         if (IS_ERR(p))
3870                 return PTR_ERR(p);
3871
3872         switch (p->cmd) {
3873         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3874                 if (sb_rdonly(fs_info->sb)) {
3875                         ret = -EROFS;
3876                         goto out;
3877                 }
3878                 if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) {
3879                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3880                 } else {
3881                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
3882                         btrfs_exclop_finish(fs_info);
3883                 }
3884                 break;
3885         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3886                 btrfs_dev_replace_status(fs_info, p);
3887                 ret = 0;
3888                 break;
3889         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3890                 p->result = btrfs_dev_replace_cancel(fs_info);
3891                 ret = 0;
3892                 break;
3893         default:
3894                 ret = -EINVAL;
3895                 break;
3896         }
3897
3898         if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
3899                 ret = -EFAULT;
3900 out:
3901         kfree(p);
3902         return ret;
3903 }
3904
3905 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3906 {
3907         int ret = 0;
3908         int i;
3909         u64 rel_ptr;
3910         int size;
3911         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3912         struct inode_fs_paths *ipath = NULL;
3913         struct btrfs_path *path;
3914
3915         if (!capable(CAP_DAC_READ_SEARCH))
3916                 return -EPERM;
3917
3918         path = btrfs_alloc_path();
3919         if (!path) {
3920                 ret = -ENOMEM;
3921                 goto out;
3922         }
3923
3924         ipa = memdup_user(arg, sizeof(*ipa));
3925         if (IS_ERR(ipa)) {
3926                 ret = PTR_ERR(ipa);
3927                 ipa = NULL;
3928                 goto out;
3929         }
3930
3931         size = min_t(u32, ipa->size, 4096);
3932         ipath = init_ipath(size, root, path);
3933         if (IS_ERR(ipath)) {
3934                 ret = PTR_ERR(ipath);
3935                 ipath = NULL;
3936                 goto out;
3937         }
3938
3939         ret = paths_from_inode(ipa->inum, ipath);
3940         if (ret < 0)
3941                 goto out;
3942
3943         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3944                 rel_ptr = ipath->fspath->val[i] -
3945                           (u64)(unsigned long)ipath->fspath->val;
3946                 ipath->fspath->val[i] = rel_ptr;
3947         }
3948
3949         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
3950                            ipath->fspath, size);
3951         if (ret) {
3952                 ret = -EFAULT;
3953                 goto out;
3954         }
3955
3956 out:
3957         btrfs_free_path(path);
3958         free_ipath(ipath);
3959         kfree(ipa);
3960
3961         return ret;
3962 }
3963
3964 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3965 {
3966         struct btrfs_data_container *inodes = ctx;
3967         const size_t c = 3 * sizeof(u64);
3968
3969         if (inodes->bytes_left >= c) {
3970                 inodes->bytes_left -= c;
3971                 inodes->val[inodes->elem_cnt] = inum;
3972                 inodes->val[inodes->elem_cnt + 1] = offset;
3973                 inodes->val[inodes->elem_cnt + 2] = root;
3974                 inodes->elem_cnt += 3;
3975         } else {
3976                 inodes->bytes_missing += c - inodes->bytes_left;
3977                 inodes->bytes_left = 0;
3978                 inodes->elem_missed += 3;
3979         }
3980
3981         return 0;
3982 }
3983
3984 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
3985                                         void __user *arg, int version)
3986 {
3987         int ret = 0;
3988         int size;
3989         struct btrfs_ioctl_logical_ino_args *loi;
3990         struct btrfs_data_container *inodes = NULL;
3991         struct btrfs_path *path = NULL;
3992         bool ignore_offset;
3993
3994         if (!capable(CAP_SYS_ADMIN))
3995                 return -EPERM;
3996
3997         loi = memdup_user(arg, sizeof(*loi));
3998         if (IS_ERR(loi))
3999                 return PTR_ERR(loi);
4000
4001         if (version == 1) {
4002                 ignore_offset = false;
4003                 size = min_t(u32, loi->size, SZ_64K);
4004         } else {
4005                 /* All reserved bits must be 0 for now */
4006                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4007                         ret = -EINVAL;
4008                         goto out_loi;
4009                 }
4010                 /* Only accept flags we have defined so far */
4011                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4012                         ret = -EINVAL;
4013                         goto out_loi;
4014                 }
4015                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4016                 size = min_t(u32, loi->size, SZ_16M);
4017         }
4018
4019         path = btrfs_alloc_path();
4020         if (!path) {
4021                 ret = -ENOMEM;
4022                 goto out;
4023         }
4024
4025         inodes = init_data_container(size);
4026         if (IS_ERR(inodes)) {
4027                 ret = PTR_ERR(inodes);
4028                 inodes = NULL;
4029                 goto out;
4030         }
4031
4032         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4033                                           build_ino_list, inodes, ignore_offset);
4034         if (ret == -EINVAL)
4035                 ret = -ENOENT;
4036         if (ret < 0)
4037                 goto out;
4038
4039         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4040                            size);
4041         if (ret)
4042                 ret = -EFAULT;
4043
4044 out:
4045         btrfs_free_path(path);
4046         kvfree(inodes);
4047 out_loi:
4048         kfree(loi);
4049
4050         return ret;
4051 }
4052
4053 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4054                                struct btrfs_ioctl_balance_args *bargs)
4055 {
4056         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4057
4058         bargs->flags = bctl->flags;
4059
4060         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4061                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4062         if (atomic_read(&fs_info->balance_pause_req))
4063                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4064         if (atomic_read(&fs_info->balance_cancel_req))
4065                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4066
4067         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4068         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4069         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4070
4071         spin_lock(&fs_info->balance_lock);
4072         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4073         spin_unlock(&fs_info->balance_lock);
4074 }
4075
4076 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4077 {
4078         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4079         struct btrfs_fs_info *fs_info = root->fs_info;
4080         struct btrfs_ioctl_balance_args *bargs;
4081         struct btrfs_balance_control *bctl;
4082         bool need_unlock; /* for mut. excl. ops lock */
4083         int ret;
4084
4085         if (!arg)
4086                 btrfs_warn(fs_info,
4087         "IOC_BALANCE ioctl (v1) is deprecated and will be removed in kernel 5.18");
4088
4089         if (!capable(CAP_SYS_ADMIN))
4090                 return -EPERM;
4091
4092         ret = mnt_want_write_file(file);
4093         if (ret)
4094                 return ret;
4095
4096 again:
4097         if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
4098                 mutex_lock(&fs_info->balance_mutex);
4099                 need_unlock = true;
4100                 goto locked;
4101         }
4102
4103         /*
4104          * mut. excl. ops lock is locked.  Three possibilities:
4105          *   (1) some other op is running
4106          *   (2) balance is running
4107          *   (3) balance is paused -- special case (think resume)
4108          */
4109         mutex_lock(&fs_info->balance_mutex);
4110         if (fs_info->balance_ctl) {
4111                 /* this is either (2) or (3) */
4112                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4113                         mutex_unlock(&fs_info->balance_mutex);
4114                         /*
4115                          * Lock released to allow other waiters to continue,
4116                          * we'll reexamine the status again.
4117                          */
4118                         mutex_lock(&fs_info->balance_mutex);
4119
4120                         if (fs_info->balance_ctl &&
4121                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4122                                 /* this is (3) */
4123                                 need_unlock = false;
4124                                 goto locked;
4125                         }
4126
4127                         mutex_unlock(&fs_info->balance_mutex);
4128                         goto again;
4129                 } else {
4130                         /* this is (2) */
4131                         mutex_unlock(&fs_info->balance_mutex);
4132                         ret = -EINPROGRESS;
4133                         goto out;
4134                 }
4135         } else {
4136                 /* this is (1) */
4137                 mutex_unlock(&fs_info->balance_mutex);
4138                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4139                 goto out;
4140         }
4141
4142 locked:
4143
4144         if (arg) {
4145                 bargs = memdup_user(arg, sizeof(*bargs));
4146                 if (IS_ERR(bargs)) {
4147                         ret = PTR_ERR(bargs);
4148                         goto out_unlock;
4149                 }
4150
4151                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4152                         if (!fs_info->balance_ctl) {
4153                                 ret = -ENOTCONN;
4154                                 goto out_bargs;
4155                         }
4156
4157                         bctl = fs_info->balance_ctl;
4158                         spin_lock(&fs_info->balance_lock);
4159                         bctl->flags |= BTRFS_BALANCE_RESUME;
4160                         spin_unlock(&fs_info->balance_lock);
4161                         btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE);
4162
4163                         goto do_balance;
4164                 }
4165         } else {
4166                 bargs = NULL;
4167         }
4168
4169         if (fs_info->balance_ctl) {
4170                 ret = -EINPROGRESS;
4171                 goto out_bargs;
4172         }
4173
4174         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4175         if (!bctl) {
4176                 ret = -ENOMEM;
4177                 goto out_bargs;
4178         }
4179
4180         if (arg) {
4181                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4182                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4183                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4184
4185                 bctl->flags = bargs->flags;
4186         } else {
4187                 /* balance everything - no filters */
4188                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4189         }
4190
4191         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4192                 ret = -EINVAL;
4193                 goto out_bctl;
4194         }
4195
4196 do_balance:
4197         /*
4198          * Ownership of bctl and exclusive operation goes to btrfs_balance.
4199          * bctl is freed in reset_balance_state, or, if restriper was paused
4200          * all the way until unmount, in free_fs_info.  The flag should be
4201          * cleared after reset_balance_state.
4202          */
4203         need_unlock = false;
4204
4205         ret = btrfs_balance(fs_info, bctl, bargs);
4206         bctl = NULL;
4207
4208         if ((ret == 0 || ret == -ECANCELED) && arg) {
4209                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4210                         ret = -EFAULT;
4211         }
4212
4213 out_bctl:
4214         kfree(bctl);
4215 out_bargs:
4216         kfree(bargs);
4217 out_unlock:
4218         mutex_unlock(&fs_info->balance_mutex);
4219         if (need_unlock)
4220                 btrfs_exclop_finish(fs_info);
4221 out:
4222         mnt_drop_write_file(file);
4223         return ret;
4224 }
4225
4226 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4227 {
4228         if (!capable(CAP_SYS_ADMIN))
4229                 return -EPERM;
4230
4231         switch (cmd) {
4232         case BTRFS_BALANCE_CTL_PAUSE:
4233                 return btrfs_pause_balance(fs_info);
4234         case BTRFS_BALANCE_CTL_CANCEL:
4235                 return btrfs_cancel_balance(fs_info);
4236         }
4237
4238         return -EINVAL;
4239 }
4240
4241 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4242                                          void __user *arg)
4243 {
4244         struct btrfs_ioctl_balance_args *bargs;
4245         int ret = 0;
4246
4247         if (!capable(CAP_SYS_ADMIN))
4248                 return -EPERM;
4249
4250         mutex_lock(&fs_info->balance_mutex);
4251         if (!fs_info->balance_ctl) {
4252                 ret = -ENOTCONN;
4253                 goto out;
4254         }
4255
4256         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4257         if (!bargs) {
4258                 ret = -ENOMEM;
4259                 goto out;
4260         }
4261
4262         btrfs_update_ioctl_balance_args(fs_info, bargs);
4263
4264         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4265                 ret = -EFAULT;
4266
4267         kfree(bargs);
4268 out:
4269         mutex_unlock(&fs_info->balance_mutex);
4270         return ret;
4271 }
4272
4273 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4274 {
4275         struct inode *inode = file_inode(file);
4276         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4277         struct btrfs_ioctl_quota_ctl_args *sa;
4278         int ret;
4279
4280         if (!capable(CAP_SYS_ADMIN))
4281                 return -EPERM;
4282
4283         ret = mnt_want_write_file(file);
4284         if (ret)
4285                 return ret;
4286
4287         sa = memdup_user(arg, sizeof(*sa));
4288         if (IS_ERR(sa)) {
4289                 ret = PTR_ERR(sa);
4290                 goto drop_write;
4291         }
4292
4293         down_write(&fs_info->subvol_sem);
4294
4295         switch (sa->cmd) {
4296         case BTRFS_QUOTA_CTL_ENABLE:
4297                 ret = btrfs_quota_enable(fs_info);
4298                 break;
4299         case BTRFS_QUOTA_CTL_DISABLE:
4300                 ret = btrfs_quota_disable(fs_info);
4301                 break;
4302         default:
4303                 ret = -EINVAL;
4304                 break;
4305         }
4306
4307         kfree(sa);
4308         up_write(&fs_info->subvol_sem);
4309 drop_write:
4310         mnt_drop_write_file(file);
4311         return ret;
4312 }
4313
4314 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4315 {
4316         struct inode *inode = file_inode(file);
4317         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4318         struct btrfs_root *root = BTRFS_I(inode)->root;
4319         struct btrfs_ioctl_qgroup_assign_args *sa;
4320         struct btrfs_trans_handle *trans;
4321         int ret;
4322         int err;
4323
4324         if (!capable(CAP_SYS_ADMIN))
4325                 return -EPERM;
4326
4327         ret = mnt_want_write_file(file);
4328         if (ret)
4329                 return ret;
4330
4331         sa = memdup_user(arg, sizeof(*sa));
4332         if (IS_ERR(sa)) {
4333                 ret = PTR_ERR(sa);
4334                 goto drop_write;
4335         }
4336
4337         trans = btrfs_join_transaction(root);
4338         if (IS_ERR(trans)) {
4339                 ret = PTR_ERR(trans);
4340                 goto out;
4341         }
4342
4343         if (sa->assign) {
4344                 ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
4345         } else {
4346                 ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
4347         }
4348
4349         /* update qgroup status and info */
4350         err = btrfs_run_qgroups(trans);
4351         if (err < 0)
4352                 btrfs_handle_fs_error(fs_info, err,
4353                                       "failed to update qgroup status and info");
4354         err = btrfs_end_transaction(trans);
4355         if (err && !ret)
4356                 ret = err;
4357
4358 out:
4359         kfree(sa);
4360 drop_write:
4361         mnt_drop_write_file(file);
4362         return ret;
4363 }
4364
4365 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4366 {
4367         struct inode *inode = file_inode(file);
4368         struct btrfs_root *root = BTRFS_I(inode)->root;
4369         struct btrfs_ioctl_qgroup_create_args *sa;
4370         struct btrfs_trans_handle *trans;
4371         int ret;
4372         int err;
4373
4374         if (!capable(CAP_SYS_ADMIN))
4375                 return -EPERM;
4376
4377         ret = mnt_want_write_file(file);
4378         if (ret)
4379                 return ret;
4380
4381         sa = memdup_user(arg, sizeof(*sa));
4382         if (IS_ERR(sa)) {
4383                 ret = PTR_ERR(sa);
4384                 goto drop_write;
4385         }
4386
4387         if (!sa->qgroupid) {
4388                 ret = -EINVAL;
4389                 goto out;
4390         }
4391
4392         trans = btrfs_join_transaction(root);
4393         if (IS_ERR(trans)) {
4394                 ret = PTR_ERR(trans);
4395                 goto out;
4396         }
4397
4398         if (sa->create) {
4399                 ret = btrfs_create_qgroup(trans, sa->qgroupid);
4400         } else {
4401                 ret = btrfs_remove_qgroup(trans, sa->qgroupid);
4402         }
4403
4404         err = btrfs_end_transaction(trans);
4405         if (err && !ret)
4406                 ret = err;
4407
4408 out:
4409         kfree(sa);
4410 drop_write:
4411         mnt_drop_write_file(file);
4412         return ret;
4413 }
4414
4415 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4416 {
4417         struct inode *inode = file_inode(file);
4418         struct btrfs_root *root = BTRFS_I(inode)->root;
4419         struct btrfs_ioctl_qgroup_limit_args *sa;
4420         struct btrfs_trans_handle *trans;
4421         int ret;
4422         int err;
4423         u64 qgroupid;
4424
4425         if (!capable(CAP_SYS_ADMIN))
4426                 return -EPERM;
4427
4428         ret = mnt_want_write_file(file);
4429         if (ret)
4430                 return ret;
4431
4432         sa = memdup_user(arg, sizeof(*sa));
4433         if (IS_ERR(sa)) {
4434                 ret = PTR_ERR(sa);
4435                 goto drop_write;
4436         }
4437
4438         trans = btrfs_join_transaction(root);
4439         if (IS_ERR(trans)) {
4440                 ret = PTR_ERR(trans);
4441                 goto out;
4442         }
4443
4444         qgroupid = sa->qgroupid;
4445         if (!qgroupid) {
4446                 /* take the current subvol as qgroup */
4447                 qgroupid = root->root_key.objectid;
4448         }
4449
4450         ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
4451
4452         err = btrfs_end_transaction(trans);
4453         if (err && !ret)
4454                 ret = err;
4455
4456 out:
4457         kfree(sa);
4458 drop_write:
4459         mnt_drop_write_file(file);
4460         return ret;
4461 }
4462
4463 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4464 {
4465         struct inode *inode = file_inode(file);
4466         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4467         struct btrfs_ioctl_quota_rescan_args *qsa;
4468         int ret;
4469
4470         if (!capable(CAP_SYS_ADMIN))
4471                 return -EPERM;
4472
4473         ret = mnt_want_write_file(file);
4474         if (ret)
4475                 return ret;
4476
4477         qsa = memdup_user(arg, sizeof(*qsa));
4478         if (IS_ERR(qsa)) {
4479                 ret = PTR_ERR(qsa);
4480                 goto drop_write;
4481         }
4482
4483         if (qsa->flags) {
4484                 ret = -EINVAL;
4485                 goto out;
4486         }
4487
4488         ret = btrfs_qgroup_rescan(fs_info);
4489
4490 out:
4491         kfree(qsa);
4492 drop_write:
4493         mnt_drop_write_file(file);
4494         return ret;
4495 }
4496
4497 static long btrfs_ioctl_quota_rescan_status(struct btrfs_fs_info *fs_info,
4498                                                 void __user *arg)
4499 {
4500         struct btrfs_ioctl_quota_rescan_args qsa = {0};
4501
4502         if (!capable(CAP_SYS_ADMIN))
4503                 return -EPERM;
4504
4505         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4506                 qsa.flags = 1;
4507                 qsa.progress = fs_info->qgroup_rescan_progress.objectid;
4508         }
4509
4510         if (copy_to_user(arg, &qsa, sizeof(qsa)))
4511                 return -EFAULT;
4512
4513         return 0;
4514 }
4515
4516 static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info,
4517                                                 void __user *arg)
4518 {
4519         if (!capable(CAP_SYS_ADMIN))
4520                 return -EPERM;
4521
4522         return btrfs_qgroup_wait_for_completion(fs_info, true);
4523 }
4524
4525 static long _btrfs_ioctl_set_received_subvol(struct file *file,
4526                                             struct user_namespace *mnt_userns,
4527                                             struct btrfs_ioctl_received_subvol_args *sa)
4528 {
4529         struct inode *inode = file_inode(file);
4530         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4531         struct btrfs_root *root = BTRFS_I(inode)->root;
4532         struct btrfs_root_item *root_item = &root->root_item;
4533         struct btrfs_trans_handle *trans;
4534         struct timespec64 ct = current_time(inode);
4535         int ret = 0;
4536         int received_uuid_changed;
4537
4538         if (!inode_owner_or_capable(mnt_userns, inode))
4539                 return -EPERM;
4540
4541         ret = mnt_want_write_file(file);
4542         if (ret < 0)
4543                 return ret;
4544
4545         down_write(&fs_info->subvol_sem);
4546
4547         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
4548                 ret = -EINVAL;
4549                 goto out;
4550         }
4551
4552         if (btrfs_root_readonly(root)) {
4553                 ret = -EROFS;
4554                 goto out;
4555         }
4556
4557         /*
4558          * 1 - root item
4559          * 2 - uuid items (received uuid + subvol uuid)
4560          */
4561         trans = btrfs_start_transaction(root, 3);
4562         if (IS_ERR(trans)) {
4563                 ret = PTR_ERR(trans);
4564                 trans = NULL;
4565                 goto out;
4566         }
4567
4568         sa->rtransid = trans->transid;
4569         sa->rtime.sec = ct.tv_sec;
4570         sa->rtime.nsec = ct.tv_nsec;
4571
4572         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4573                                        BTRFS_UUID_SIZE);
4574         if (received_uuid_changed &&
4575             !btrfs_is_empty_uuid(root_item->received_uuid)) {
4576                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
4577                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4578                                           root->root_key.objectid);
4579                 if (ret && ret != -ENOENT) {
4580                         btrfs_abort_transaction(trans, ret);
4581                         btrfs_end_transaction(trans);
4582                         goto out;
4583                 }
4584         }
4585         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4586         btrfs_set_root_stransid(root_item, sa->stransid);
4587         btrfs_set_root_rtransid(root_item, sa->rtransid);
4588         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4589         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4590         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4591         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4592
4593         ret = btrfs_update_root(trans, fs_info->tree_root,
4594                                 &root->root_key, &root->root_item);
4595         if (ret < 0) {
4596                 btrfs_end_transaction(trans);
4597                 goto out;
4598         }
4599         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4600                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
4601                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4602                                           root->root_key.objectid);
4603                 if (ret < 0 && ret != -EEXIST) {
4604                         btrfs_abort_transaction(trans, ret);
4605                         btrfs_end_transaction(trans);
4606                         goto out;
4607                 }
4608         }
4609         ret = btrfs_commit_transaction(trans);
4610 out:
4611         up_write(&fs_info->subvol_sem);
4612         mnt_drop_write_file(file);
4613         return ret;
4614 }
4615
4616 #ifdef CONFIG_64BIT
4617 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4618                                                 void __user *arg)
4619 {
4620         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4621         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4622         int ret = 0;
4623
4624         args32 = memdup_user(arg, sizeof(*args32));
4625         if (IS_ERR(args32))
4626                 return PTR_ERR(args32);
4627
4628         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
4629         if (!args64) {
4630                 ret = -ENOMEM;
4631                 goto out;
4632         }
4633
4634         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4635         args64->stransid = args32->stransid;
4636         args64->rtransid = args32->rtransid;
4637         args64->stime.sec = args32->stime.sec;
4638         args64->stime.nsec = args32->stime.nsec;
4639         args64->rtime.sec = args32->rtime.sec;
4640         args64->rtime.nsec = args32->rtime.nsec;
4641         args64->flags = args32->flags;
4642
4643         ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_user_ns(file), args64);
4644         if (ret)
4645                 goto out;
4646
4647         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4648         args32->stransid = args64->stransid;
4649         args32->rtransid = args64->rtransid;
4650         args32->stime.sec = args64->stime.sec;
4651         args32->stime.nsec = args64->stime.nsec;
4652         args32->rtime.sec = args64->rtime.sec;
4653         args32->rtime.nsec = args64->rtime.nsec;
4654         args32->flags = args64->flags;
4655
4656         ret = copy_to_user(arg, args32, sizeof(*args32));
4657         if (ret)
4658                 ret = -EFAULT;
4659
4660 out:
4661         kfree(args32);
4662         kfree(args64);
4663         return ret;
4664 }
4665 #endif
4666
4667 static long btrfs_ioctl_set_received_subvol(struct file *file,
4668                                             void __user *arg)
4669 {
4670         struct btrfs_ioctl_received_subvol_args *sa = NULL;
4671         int ret = 0;
4672
4673         sa = memdup_user(arg, sizeof(*sa));
4674         if (IS_ERR(sa))
4675                 return PTR_ERR(sa);
4676
4677         ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_user_ns(file), sa);
4678
4679         if (ret)
4680                 goto out;
4681
4682         ret = copy_to_user(arg, sa, sizeof(*sa));
4683         if (ret)
4684                 ret = -EFAULT;
4685
4686 out:
4687         kfree(sa);
4688         return ret;
4689 }
4690
4691 static int btrfs_ioctl_get_fslabel(struct btrfs_fs_info *fs_info,
4692                                         void __user *arg)
4693 {
4694         size_t len;
4695         int ret;
4696         char label[BTRFS_LABEL_SIZE];
4697
4698         spin_lock(&fs_info->super_lock);
4699         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4700         spin_unlock(&fs_info->super_lock);
4701
4702         len = strnlen(label, BTRFS_LABEL_SIZE);
4703
4704         if (len == BTRFS_LABEL_SIZE) {
4705                 btrfs_warn(fs_info,
4706                            "label is too long, return the first %zu bytes",
4707                            --len);
4708         }
4709
4710         ret = copy_to_user(arg, label, len);
4711
4712         return ret ? -EFAULT : 0;
4713 }
4714
4715 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4716 {
4717         struct inode *inode = file_inode(file);
4718         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4719         struct btrfs_root *root = BTRFS_I(inode)->root;
4720         struct btrfs_super_block *super_block = fs_info->super_copy;
4721         struct btrfs_trans_handle *trans;
4722         char label[BTRFS_LABEL_SIZE];
4723         int ret;
4724
4725         if (!capable(CAP_SYS_ADMIN))
4726                 return -EPERM;
4727
4728         if (copy_from_user(label, arg, sizeof(label)))
4729                 return -EFAULT;
4730
4731         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4732                 btrfs_err(fs_info,
4733                           "unable to set label with more than %d bytes",
4734                           BTRFS_LABEL_SIZE - 1);
4735                 return -EINVAL;
4736         }
4737
4738         ret = mnt_want_write_file(file);
4739         if (ret)
4740                 return ret;
4741
4742         trans = btrfs_start_transaction(root, 0);
4743         if (IS_ERR(trans)) {
4744                 ret = PTR_ERR(trans);
4745                 goto out_unlock;
4746         }
4747
4748         spin_lock(&fs_info->super_lock);
4749         strcpy(super_block->label, label);
4750         spin_unlock(&fs_info->super_lock);
4751         ret = btrfs_commit_transaction(trans);
4752
4753 out_unlock:
4754         mnt_drop_write_file(file);
4755         return ret;
4756 }
4757
4758 #define INIT_FEATURE_FLAGS(suffix) \
4759         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
4760           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
4761           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
4762
4763 int btrfs_ioctl_get_supported_features(void __user *arg)
4764 {
4765         static const struct btrfs_ioctl_feature_flags features[3] = {
4766                 INIT_FEATURE_FLAGS(SUPP),
4767                 INIT_FEATURE_FLAGS(SAFE_SET),
4768                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
4769         };
4770
4771         if (copy_to_user(arg, &features, sizeof(features)))
4772                 return -EFAULT;
4773
4774         return 0;
4775 }
4776
4777 static int btrfs_ioctl_get_features(struct btrfs_fs_info *fs_info,
4778                                         void __user *arg)
4779 {
4780         struct btrfs_super_block *super_block = fs_info->super_copy;
4781         struct btrfs_ioctl_feature_flags features;
4782
4783         features.compat_flags = btrfs_super_compat_flags(super_block);
4784         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
4785         features.incompat_flags = btrfs_super_incompat_flags(super_block);
4786
4787         if (copy_to_user(arg, &features, sizeof(features)))
4788                 return -EFAULT;
4789
4790         return 0;
4791 }
4792
4793 static int check_feature_bits(struct btrfs_fs_info *fs_info,
4794                               enum btrfs_feature_set set,
4795                               u64 change_mask, u64 flags, u64 supported_flags,
4796                               u64 safe_set, u64 safe_clear)
4797 {
4798         const char *type = btrfs_feature_set_name(set);
4799         char *names;
4800         u64 disallowed, unsupported;
4801         u64 set_mask = flags & change_mask;
4802         u64 clear_mask = ~flags & change_mask;
4803
4804         unsupported = set_mask & ~supported_flags;
4805         if (unsupported) {
4806                 names = btrfs_printable_features(set, unsupported);
4807                 if (names) {
4808                         btrfs_warn(fs_info,
4809                                    "this kernel does not support the %s feature bit%s",
4810                                    names, strchr(names, ',') ? "s" : "");
4811                         kfree(names);
4812                 } else
4813                         btrfs_warn(fs_info,
4814                                    "this kernel does not support %s bits 0x%llx",
4815                                    type, unsupported);
4816                 return -EOPNOTSUPP;
4817         }
4818
4819         disallowed = set_mask & ~safe_set;
4820         if (disallowed) {
4821                 names = btrfs_printable_features(set, disallowed);
4822                 if (names) {
4823                         btrfs_warn(fs_info,
4824                                    "can't set the %s feature bit%s while mounted",
4825                                    names, strchr(names, ',') ? "s" : "");
4826                         kfree(names);
4827                 } else
4828                         btrfs_warn(fs_info,
4829                                    "can't set %s bits 0x%llx while mounted",
4830                                    type, disallowed);
4831                 return -EPERM;
4832         }
4833
4834         disallowed = clear_mask & ~safe_clear;
4835         if (disallowed) {
4836                 names = btrfs_printable_features(set, disallowed);
4837                 if (names) {
4838                         btrfs_warn(fs_info,
4839                                    "can't clear the %s feature bit%s while mounted",
4840                                    names, strchr(names, ',') ? "s" : "");
4841                         kfree(names);
4842                 } else
4843                         btrfs_warn(fs_info,
4844                                    "can't clear %s bits 0x%llx while mounted",
4845                                    type, disallowed);
4846                 return -EPERM;
4847         }
4848
4849         return 0;
4850 }
4851
4852 #define check_feature(fs_info, change_mask, flags, mask_base)   \
4853 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
4854                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
4855                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
4856                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
4857
4858 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
4859 {
4860         struct inode *inode = file_inode(file);
4861         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4862         struct btrfs_root *root = BTRFS_I(inode)->root;
4863         struct btrfs_super_block *super_block = fs_info->super_copy;
4864         struct btrfs_ioctl_feature_flags flags[2];
4865         struct btrfs_trans_handle *trans;
4866         u64 newflags;
4867         int ret;
4868
4869         if (!capable(CAP_SYS_ADMIN))
4870                 return -EPERM;
4871
4872         if (copy_from_user(flags, arg, sizeof(flags)))
4873                 return -EFAULT;
4874
4875         /* Nothing to do */
4876         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
4877             !flags[0].incompat_flags)
4878                 return 0;
4879
4880         ret = check_feature(fs_info, flags[0].compat_flags,
4881                             flags[1].compat_flags, COMPAT);
4882         if (ret)
4883                 return ret;
4884
4885         ret = check_feature(fs_info, flags[0].compat_ro_flags,
4886                             flags[1].compat_ro_flags, COMPAT_RO);
4887         if (ret)
4888                 return ret;
4889
4890         ret = check_feature(fs_info, flags[0].incompat_flags,
4891                             flags[1].incompat_flags, INCOMPAT);
4892         if (ret)
4893                 return ret;
4894
4895         ret = mnt_want_write_file(file);
4896         if (ret)
4897                 return ret;
4898
4899         trans = btrfs_start_transaction(root, 0);
4900         if (IS_ERR(trans)) {
4901                 ret = PTR_ERR(trans);
4902                 goto out_drop_write;
4903         }
4904
4905         spin_lock(&fs_info->super_lock);
4906         newflags = btrfs_super_compat_flags(super_block);
4907         newflags |= flags[0].compat_flags & flags[1].compat_flags;
4908         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
4909         btrfs_set_super_compat_flags(super_block, newflags);
4910
4911         newflags = btrfs_super_compat_ro_flags(super_block);
4912         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
4913         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
4914         btrfs_set_super_compat_ro_flags(super_block, newflags);
4915
4916         newflags = btrfs_super_incompat_flags(super_block);
4917         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
4918         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
4919         btrfs_set_super_incompat_flags(super_block, newflags);
4920         spin_unlock(&fs_info->super_lock);
4921
4922         ret = btrfs_commit_transaction(trans);
4923 out_drop_write:
4924         mnt_drop_write_file(file);
4925
4926         return ret;
4927 }
4928
4929 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
4930 {
4931         struct btrfs_ioctl_send_args *arg;
4932         int ret;
4933
4934         if (compat) {
4935 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4936                 struct btrfs_ioctl_send_args_32 args32;
4937
4938                 ret = copy_from_user(&args32, argp, sizeof(args32));
4939                 if (ret)
4940                         return -EFAULT;
4941                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
4942                 if (!arg)
4943                         return -ENOMEM;
4944                 arg->send_fd = args32.send_fd;
4945                 arg->clone_sources_count = args32.clone_sources_count;
4946                 arg->clone_sources = compat_ptr(args32.clone_sources);
4947                 arg->parent_root = args32.parent_root;
4948                 arg->flags = args32.flags;
4949                 memcpy(arg->reserved, args32.reserved,
4950                        sizeof(args32.reserved));
4951 #else
4952                 return -ENOTTY;
4953 #endif
4954         } else {
4955                 arg = memdup_user(argp, sizeof(*arg));
4956                 if (IS_ERR(arg))
4957                         return PTR_ERR(arg);
4958         }
4959         ret = btrfs_ioctl_send(file, arg);
4960         kfree(arg);
4961         return ret;
4962 }
4963
4964 long btrfs_ioctl(struct file *file, unsigned int
4965                 cmd, unsigned long arg)
4966 {
4967         struct inode *inode = file_inode(file);
4968         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4969         struct btrfs_root *root = BTRFS_I(inode)->root;
4970         void __user *argp = (void __user *)arg;
4971
4972         switch (cmd) {
4973         case FS_IOC_GETVERSION:
4974                 return btrfs_ioctl_getversion(file, argp);
4975         case FS_IOC_GETFSLABEL:
4976                 return btrfs_ioctl_get_fslabel(fs_info, argp);
4977         case FS_IOC_SETFSLABEL:
4978                 return btrfs_ioctl_set_fslabel(file, argp);
4979         case FITRIM:
4980                 return btrfs_ioctl_fitrim(fs_info, argp);
4981         case BTRFS_IOC_SNAP_CREATE:
4982                 return btrfs_ioctl_snap_create(file, argp, 0);
4983         case BTRFS_IOC_SNAP_CREATE_V2:
4984                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
4985         case BTRFS_IOC_SUBVOL_CREATE:
4986                 return btrfs_ioctl_snap_create(file, argp, 1);
4987         case BTRFS_IOC_SUBVOL_CREATE_V2:
4988                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
4989         case BTRFS_IOC_SNAP_DESTROY:
4990                 return btrfs_ioctl_snap_destroy(file, argp, false);
4991         case BTRFS_IOC_SNAP_DESTROY_V2:
4992                 return btrfs_ioctl_snap_destroy(file, argp, true);
4993         case BTRFS_IOC_SUBVOL_GETFLAGS:
4994                 return btrfs_ioctl_subvol_getflags(file, argp);
4995         case BTRFS_IOC_SUBVOL_SETFLAGS:
4996                 return btrfs_ioctl_subvol_setflags(file, argp);
4997         case BTRFS_IOC_DEFAULT_SUBVOL:
4998                 return btrfs_ioctl_default_subvol(file, argp);
4999         case BTRFS_IOC_DEFRAG:
5000                 return btrfs_ioctl_defrag(file, NULL);
5001         case BTRFS_IOC_DEFRAG_RANGE:
5002                 return btrfs_ioctl_defrag(file, argp);
5003         case BTRFS_IOC_RESIZE:
5004                 return btrfs_ioctl_resize(file, argp);
5005         case BTRFS_IOC_ADD_DEV:
5006                 return btrfs_ioctl_add_dev(fs_info, argp);
5007         case BTRFS_IOC_RM_DEV:
5008                 return btrfs_ioctl_rm_dev(file, argp);
5009         case BTRFS_IOC_RM_DEV_V2:
5010                 return btrfs_ioctl_rm_dev_v2(file, argp);
5011         case BTRFS_IOC_FS_INFO:
5012                 return btrfs_ioctl_fs_info(fs_info, argp);
5013         case BTRFS_IOC_DEV_INFO:
5014                 return btrfs_ioctl_dev_info(fs_info, argp);
5015         case BTRFS_IOC_BALANCE:
5016                 return btrfs_ioctl_balance(file, NULL);
5017         case BTRFS_IOC_TREE_SEARCH:
5018                 return btrfs_ioctl_tree_search(file, argp);
5019         case BTRFS_IOC_TREE_SEARCH_V2:
5020                 return btrfs_ioctl_tree_search_v2(file, argp);
5021         case BTRFS_IOC_INO_LOOKUP:
5022                 return btrfs_ioctl_ino_lookup(file, argp);
5023         case BTRFS_IOC_INO_PATHS:
5024                 return btrfs_ioctl_ino_to_path(root, argp);
5025         case BTRFS_IOC_LOGICAL_INO:
5026                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5027         case BTRFS_IOC_LOGICAL_INO_V2:
5028                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5029         case BTRFS_IOC_SPACE_INFO:
5030                 return btrfs_ioctl_space_info(fs_info, argp);
5031         case BTRFS_IOC_SYNC: {
5032                 int ret;
5033
5034                 ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false);
5035                 if (ret)
5036                         return ret;
5037                 ret = btrfs_sync_fs(inode->i_sb, 1);
5038                 /*
5039                  * The transaction thread may want to do more work,
5040                  * namely it pokes the cleaner kthread that will start
5041                  * processing uncleaned subvols.
5042                  */
5043                 wake_up_process(fs_info->transaction_kthread);
5044                 return ret;
5045         }
5046         case BTRFS_IOC_START_SYNC:
5047                 return btrfs_ioctl_start_sync(root, argp);
5048         case BTRFS_IOC_WAIT_SYNC:
5049                 return btrfs_ioctl_wait_sync(fs_info, argp);
5050         case BTRFS_IOC_SCRUB:
5051                 return btrfs_ioctl_scrub(file, argp);
5052         case BTRFS_IOC_SCRUB_CANCEL:
5053                 return btrfs_ioctl_scrub_cancel(fs_info);
5054         case BTRFS_IOC_SCRUB_PROGRESS:
5055                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5056         case BTRFS_IOC_BALANCE_V2:
5057                 return btrfs_ioctl_balance(file, argp);
5058         case BTRFS_IOC_BALANCE_CTL:
5059                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5060         case BTRFS_IOC_BALANCE_PROGRESS:
5061                 return btrfs_ioctl_balance_progress(fs_info, argp);
5062         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5063                 return btrfs_ioctl_set_received_subvol(file, argp);
5064 #ifdef CONFIG_64BIT
5065         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5066                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5067 #endif
5068         case BTRFS_IOC_SEND:
5069                 return _btrfs_ioctl_send(file, argp, false);
5070 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5071         case BTRFS_IOC_SEND_32:
5072                 return _btrfs_ioctl_send(file, argp, true);
5073 #endif
5074         case BTRFS_IOC_GET_DEV_STATS:
5075                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5076         case BTRFS_IOC_QUOTA_CTL:
5077                 return btrfs_ioctl_quota_ctl(file, argp);
5078         case BTRFS_IOC_QGROUP_ASSIGN:
5079                 return btrfs_ioctl_qgroup_assign(file, argp);
5080         case BTRFS_IOC_QGROUP_CREATE:
5081                 return btrfs_ioctl_qgroup_create(file, argp);
5082         case BTRFS_IOC_QGROUP_LIMIT:
5083                 return btrfs_ioctl_qgroup_limit(file, argp);
5084         case BTRFS_IOC_QUOTA_RESCAN:
5085                 return btrfs_ioctl_quota_rescan(file, argp);
5086         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5087                 return btrfs_ioctl_quota_rescan_status(fs_info, argp);
5088         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5089                 return btrfs_ioctl_quota_rescan_wait(fs_info, argp);
5090         case BTRFS_IOC_DEV_REPLACE:
5091                 return btrfs_ioctl_dev_replace(fs_info, argp);
5092         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5093                 return btrfs_ioctl_get_supported_features(argp);
5094         case BTRFS_IOC_GET_FEATURES:
5095                 return btrfs_ioctl_get_features(fs_info, argp);
5096         case BTRFS_IOC_SET_FEATURES:
5097                 return btrfs_ioctl_set_features(file, argp);
5098         case BTRFS_IOC_GET_SUBVOL_INFO:
5099                 return btrfs_ioctl_get_subvol_info(file, argp);
5100         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5101                 return btrfs_ioctl_get_subvol_rootref(file, argp);
5102         case BTRFS_IOC_INO_LOOKUP_USER:
5103                 return btrfs_ioctl_ino_lookup_user(file, argp);
5104         case FS_IOC_ENABLE_VERITY:
5105                 return fsverity_ioctl_enable(file, (const void __user *)argp);
5106         case FS_IOC_MEASURE_VERITY:
5107                 return fsverity_ioctl_measure(file, argp);
5108         }
5109
5110         return -ENOTTY;
5111 }
5112
5113 #ifdef CONFIG_COMPAT
5114 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5115 {
5116         /*
5117          * These all access 32-bit values anyway so no further
5118          * handling is necessary.
5119          */
5120         switch (cmd) {
5121         case FS_IOC32_GETVERSION:
5122                 cmd = FS_IOC_GETVERSION;
5123                 break;
5124         }
5125
5126         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5127 }
5128 #endif