fs/btrfs/ioctl.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/bio.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/file.h>
  23 #include <linux/fs.h>
  24 #include <linux/fsnotify.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/highmem.h>
  27 #include <linux/time.h>
  28 #include <linux/init.h>
  29 #include <linux/string.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/mount.h>
  32 #include <linux/mpage.h>
  33 #include <linux/namei.h>
  34 #include <linux/swap.h>
  35 #include <linux/writeback.h>
  36 #include <linux/statfs.h>
  37 #include <linux/compat.h>
  38 #include <linux/bit_spinlock.h>
  39 #include <linux/security.h>
  40 #include <linux/xattr.h>
  41 #include <linux/vmalloc.h>
  42 #include <linux/slab.h>
  43 #include <linux/blkdev.h>
  44 #include <linux/uuid.h>
  45 #include <linux/btrfs.h>
  46 #include <linux/uaccess.h>
  47 #include "ctree.h"
  48 #include "disk-io.h"
  49 #include "transaction.h"
  50 #include "btrfs_inode.h"
  51 #include "print-tree.h"
  52 #include "volumes.h"
  53 #include "locking.h"
  54 #include "inode-map.h"
  55 #include "backref.h"
  56 #include "rcu-string.h"
  57 #include "send.h"
  58 #include "dev-replace.h"
  59 #include "props.h"
  60 #include "sysfs.h"
  61 #include "qgroup.h"
  62
  63 #ifdef CONFIG_64BIT
  64 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  65  * structures are incorrect, as the timespec structure from userspace
  66  * is 4 bytes too small. We define these alternatives here to teach
  67  * the kernel about the 32-bit struct packing.
  68  */
  69 struct btrfs_ioctl_timespec_32 {
  70         __u64 sec;
  71         __u32 nsec;
  72 } __attribute__ ((__packed__));
  73
  74 struct btrfs_ioctl_received_subvol_args_32 {
  75         char    uuid[BTRFS_UUID_SIZE];  /* in */
  76         __u64   stransid;               /* in */
  77         __u64   rtransid;               /* out */
  78         struct btrfs_ioctl_timespec_32 stime; /* in */
  79         struct btrfs_ioctl_timespec_32 rtime; /* out */
  80         __u64   flags;                  /* in */
  81         __u64   reserved[16];           /* in */
  82 } __attribute__ ((__packed__));
  83
  84 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  85                                 struct btrfs_ioctl_received_subvol_args_32)
  86 #endif
  87
  88
  89 static int btrfs_clone(struct inode *src, struct inode *inode,
  90                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  91                        int no_time_update);
  92
  93 /* Mask out flags that are inappropriate for the given type of inode. */
  94 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  95 {
  96         if (S_ISDIR(mode))
  97                 return flags;
  98         else if (S_ISREG(mode))
  99                 return flags & ~FS_DIRSYNC_FL;
 100         else
 101                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 102 }
 103
 104 /*
 105  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
 106  */
 107 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
 108 {
 109         unsigned int iflags = 0;
 110
 111         if (flags & BTRFS_INODE_SYNC)
 112                 iflags |= FS_SYNC_FL;
 113         if (flags & BTRFS_INODE_IMMUTABLE)
 114                 iflags |= FS_IMMUTABLE_FL;
 115         if (flags & BTRFS_INODE_APPEND)
 116                 iflags |= FS_APPEND_FL;
 117         if (flags & BTRFS_INODE_NODUMP)
 118                 iflags |= FS_NODUMP_FL;
 119         if (flags & BTRFS_INODE_NOATIME)
 120                 iflags |= FS_NOATIME_FL;
 121         if (flags & BTRFS_INODE_DIRSYNC)
 122                 iflags |= FS_DIRSYNC_FL;
 123         if (flags & BTRFS_INODE_NODATACOW)
 124                 iflags |= FS_NOCOW_FL;
 125
 126         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
 127                 iflags |= FS_COMPR_FL;
 128         else if (flags & BTRFS_INODE_NOCOMPRESS)
 129                 iflags |= FS_NOCOMP_FL;
 130
 131         return iflags;
 132 }
 133
 134 /*
 135  * Update inode->i_flags based on the btrfs internal flags.
 136  */
 137 void btrfs_update_iflags(struct inode *inode)
 138 {
 139         struct btrfs_inode *ip = BTRFS_I(inode);
 140         unsigned int new_fl = 0;
 141
 142         if (ip->flags & BTRFS_INODE_SYNC)
 143                 new_fl |= S_SYNC;
 144         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 145                 new_fl |= S_IMMUTABLE;
 146         if (ip->flags & BTRFS_INODE_APPEND)
 147                 new_fl |= S_APPEND;
 148         if (ip->flags & BTRFS_INODE_NOATIME)
 149                 new_fl |= S_NOATIME;
 150         if (ip->flags & BTRFS_INODE_DIRSYNC)
 151                 new_fl |= S_DIRSYNC;
 152
 153         set_mask_bits(&inode->i_flags,
 154                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 155                       new_fl);
 156 }
 157
 158 /*
 159  * Inherit flags from the parent inode.
 160  *
 161  * Currently only the compression flags and the cow flags are inherited.
 162  */
 163 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 164 {
 165         unsigned int flags;
 166
 167         if (!dir)
 168                 return;
 169
 170         flags = BTRFS_I(dir)->flags;
 171
 172         if (flags & BTRFS_INODE_NOCOMPRESS) {
 173                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 174                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 175         } else if (flags & BTRFS_INODE_COMPRESS) {
 176                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 177                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 178         }
 179
 180         if (flags & BTRFS_INODE_NODATACOW) {
 181                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 182                 if (S_ISREG(inode->i_mode))
 183                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
 184         }
 185
 186         btrfs_update_iflags(inode);
 187 }
 188
 189 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 190 {
 191         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 192         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 193
 194         if (copy_to_user(arg, &flags, sizeof(flags)))
 195                 return -EFAULT;
 196         return 0;
 197 }
 198
 199 static int check_flags(unsigned int flags)
 200 {
 201         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 202                       FS_NOATIME_FL | FS_NODUMP_FL | \
 203                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 204                       FS_NOCOMP_FL | FS_COMPR_FL |
 205                       FS_NOCOW_FL))
 206                 return -EOPNOTSUPP;
 207
 208         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 209                 return -EINVAL;
 210
 211         return 0;
 212 }
 213
 214 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 215 {
 216         struct inode *inode = file_inode(file);
 217         struct btrfs_inode *ip = BTRFS_I(inode);
 218         struct btrfs_root *root = ip->root;
 219         struct btrfs_trans_handle *trans;
 220         unsigned int flags, oldflags;
 221         int ret;
 222         u64 ip_oldflags;
 223         unsigned int i_oldflags;
 224         umode_t mode;
 225
 226         if (!inode_owner_or_capable(inode))
 227                 return -EPERM;
 228
 229         if (btrfs_root_readonly(root))
 230                 return -EROFS;
 231
 232         if (copy_from_user(&flags, arg, sizeof(flags)))
 233                 return -EFAULT;
 234
 235         ret = check_flags(flags);
 236         if (ret)
 237                 return ret;
 238
 239         ret = mnt_want_write_file(file);
 240         if (ret)
 241                 return ret;
 242
 243         mutex_lock(&inode->i_mutex);
 244
 245         ip_oldflags = ip->flags;
 246         i_oldflags = inode->i_flags;
 247         mode = inode->i_mode;
 248
 249         flags = btrfs_mask_flags(inode->i_mode, flags);
 250         oldflags = btrfs_flags_to_ioctl(ip->flags);
 251         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 252                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 253                         ret = -EPERM;
 254                         goto out_unlock;
 255                 }
 256         }
 257
 258         if (flags & FS_SYNC_FL)
 259                 ip->flags |= BTRFS_INODE_SYNC;
 260         else
 261                 ip->flags &= ~BTRFS_INODE_SYNC;
 262         if (flags & FS_IMMUTABLE_FL)
 263                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 264         else
 265                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 266         if (flags & FS_APPEND_FL)
 267                 ip->flags |= BTRFS_INODE_APPEND;
 268         else
 269                 ip->flags &= ~BTRFS_INODE_APPEND;
 270         if (flags & FS_NODUMP_FL)
 271                 ip->flags |= BTRFS_INODE_NODUMP;
 272         else
 273                 ip->flags &= ~BTRFS_INODE_NODUMP;
 274         if (flags & FS_NOATIME_FL)
 275                 ip->flags |= BTRFS_INODE_NOATIME;
 276         else
 277                 ip->flags &= ~BTRFS_INODE_NOATIME;
 278         if (flags & FS_DIRSYNC_FL)
 279                 ip->flags |= BTRFS_INODE_DIRSYNC;
 280         else
 281                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 282         if (flags & FS_NOCOW_FL) {
 283                 if (S_ISREG(mode)) {
 284                         /*
 285                          * It's safe to turn csums off here, no extents exist.
 286                          * Otherwise we want the flag to reflect the real COW
 287                          * status of the file and will not set it.
 288                          */
 289                         if (inode->i_size == 0)
 290                                 ip->flags |= BTRFS_INODE_NODATACOW
 291                                            | BTRFS_INODE_NODATASUM;
 292                 } else {
 293                         ip->flags |= BTRFS_INODE_NODATACOW;
 294                 }
 295         } else {
 296                 /*
 297                  * Revert back under same assuptions as above
 298                  */
 299                 if (S_ISREG(mode)) {
 300                         if (inode->i_size == 0)
 301                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 302                                              | BTRFS_INODE_NODATASUM);
 303                 } else {
 304                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 305                 }
 306         }
 307
 308         /*
 309          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 310          * flag may be changed automatically if compression code won't make
 311          * things smaller.
 312          */
 313         if (flags & FS_NOCOMP_FL) {
 314                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 315                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 316
 317                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 318                 if (ret && ret != -ENODATA)
 319                         goto out_drop;
 320         } else if (flags & FS_COMPR_FL) {
 321                 const char *comp;
 322
 323                 ip->flags |= BTRFS_INODE_COMPRESS;
 324                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 325
 326                 if (root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
 327                         comp = "lzo";
 328                 else
 329                         comp = "zlib";
 330                 ret = btrfs_set_prop(inode, "btrfs.compression",
 331                                      comp, strlen(comp), 0);
 332                 if (ret)
 333                         goto out_drop;
 334
 335         } else {
 336                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 337                 if (ret && ret != -ENODATA)
 338                         goto out_drop;
 339                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 340         }
 341
 342         trans = btrfs_start_transaction(root, 1);
 343         if (IS_ERR(trans)) {
 344                 ret = PTR_ERR(trans);
 345                 goto out_drop;
 346         }
 347
 348         btrfs_update_iflags(inode);
 349         inode_inc_iversion(inode);
 350         inode->i_ctime = CURRENT_TIME;
 351         ret = btrfs_update_inode(trans, root, inode);
 352
 353         btrfs_end_transaction(trans, root);
 354  out_drop:
 355         if (ret) {
 356                 ip->flags = ip_oldflags;
 357                 inode->i_flags = i_oldflags;
 358         }
 359
 360  out_unlock:
 361         mutex_unlock(&inode->i_mutex);
 362         mnt_drop_write_file(file);
 363         return ret;
 364 }
 365
 366 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 367 {
 368         struct inode *inode = file_inode(file);
 369
 370         return put_user(inode->i_generation, arg);
 371 }
 372
 373 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 374 {
 375         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
 376         struct btrfs_device *device;
 377         struct request_queue *q;
 378         struct fstrim_range range;
 379         u64 minlen = ULLONG_MAX;
 380         u64 num_devices = 0;
 381         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 382         int ret;
 383
 384         if (!capable(CAP_SYS_ADMIN))
 385                 return -EPERM;
 386
 387         rcu_read_lock();
 388         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 389                                 dev_list) {
 390                 if (!device->bdev)
 391                         continue;
 392                 q = bdev_get_queue(device->bdev);
 393                 if (blk_queue_discard(q)) {
 394                         num_devices++;
 395                         minlen = min((u64)q->limits.discard_granularity,
 396                                      minlen);
 397                 }
 398         }
 399         rcu_read_unlock();
 400
 401         if (!num_devices)
 402                 return -EOPNOTSUPP;
 403         if (copy_from_user(&range, arg, sizeof(range)))
 404                 return -EFAULT;
 405         if (range.start > total_bytes ||
 406             range.len < fs_info->sb->s_blocksize)
 407                 return -EINVAL;
 408
 409         range.len = min(range.len, total_bytes - range.start);
 410         range.minlen = max(range.minlen, minlen);
 411         ret = btrfs_trim_fs(fs_info->tree_root, &range);
 412         if (ret < 0)
 413                 return ret;
 414
 415         if (copy_to_user(arg, &range, sizeof(range)))
 416                 return -EFAULT;
 417
 418         return 0;
 419 }
 420
 421 int btrfs_is_empty_uuid(u8 *uuid)
 422 {
 423         int i;
 424
 425         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 426                 if (uuid[i])
 427                         return 0;
 428         }
 429         return 1;
 430 }
 431
 432 static noinline int create_subvol(struct inode *dir,
 433                                   struct dentry *dentry,
 434                                   char *name, int namelen,
 435                                   u64 *async_transid,
 436                                   struct btrfs_qgroup_inherit *inherit)
 437 {
 438         struct btrfs_trans_handle *trans;
 439         struct btrfs_key key;
 440         struct btrfs_root_item root_item;
 441         struct btrfs_inode_item *inode_item;
 442         struct extent_buffer *leaf;
 443         struct btrfs_root *root = BTRFS_I(dir)->root;
 444         struct btrfs_root *new_root;
 445         struct btrfs_block_rsv block_rsv;
 446         struct timespec cur_time = CURRENT_TIME;
 447         struct inode *inode;
 448         int ret;
 449         int err;
 450         u64 objectid;
 451         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 452         u64 index = 0;
 453         u64 qgroup_reserved;
 454         uuid_le new_uuid;
 455
 456         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 457         if (ret)
 458                 return ret;
 459
 460         /*
 461          * Don't create subvolume whose level is not zero. Or qgroup will be
 462          * screwed up since it assume subvolme qgroup's level to be 0.
 463          */
 464         if (btrfs_qgroup_level(objectid))
 465                 return -ENOSPC;
 466
 467         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 468         /*
 469          * The same as the snapshot creation, please see the comment
 470          * of create_snapshot().
 471          */
 472         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 473                                                8, &qgroup_reserved, false);
 474         if (ret)
 475                 return ret;
 476
 477         trans = btrfs_start_transaction(root, 0);
 478         if (IS_ERR(trans)) {
 479                 ret = PTR_ERR(trans);
 480                 btrfs_subvolume_release_metadata(root, &block_rsv,
 481                                                  qgroup_reserved);
 482                 return ret;
 483         }
 484         trans->block_rsv = &block_rsv;
 485         trans->bytes_reserved = block_rsv.size;
 486
 487         ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
 488         if (ret)
 489                 goto fail;
 490
 491         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 492         if (IS_ERR(leaf)) {
 493                 ret = PTR_ERR(leaf);
 494                 goto fail;
 495         }
 496
 497         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 498         btrfs_set_header_bytenr(leaf, leaf->start);
 499         btrfs_set_header_generation(leaf, trans->transid);
 500         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 501         btrfs_set_header_owner(leaf, objectid);
 502
 503         write_extent_buffer(leaf, root->fs_info->fsid, btrfs_header_fsid(),
 504                             BTRFS_FSID_SIZE);
 505         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 506                             btrfs_header_chunk_tree_uuid(leaf),
 507                             BTRFS_UUID_SIZE);
 508         btrfs_mark_buffer_dirty(leaf);
 509
 510         memset(&root_item, 0, sizeof(root_item));
 511
 512         inode_item = &root_item.inode;
 513         btrfs_set_stack_inode_generation(inode_item, 1);
 514         btrfs_set_stack_inode_size(inode_item, 3);
 515         btrfs_set_stack_inode_nlink(inode_item, 1);
 516         btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
 517         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 518
 519         btrfs_set_root_flags(&root_item, 0);
 520         btrfs_set_root_limit(&root_item, 0);
 521         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 522
 523         btrfs_set_root_bytenr(&root_item, leaf->start);
 524         btrfs_set_root_generation(&root_item, trans->transid);
 525         btrfs_set_root_level(&root_item, 0);
 526         btrfs_set_root_refs(&root_item, 1);
 527         btrfs_set_root_used(&root_item, leaf->len);
 528         btrfs_set_root_last_snapshot(&root_item, 0);
 529
 530         btrfs_set_root_generation_v2(&root_item,
 531                         btrfs_root_generation(&root_item));
 532         uuid_le_gen(&new_uuid);
 533         memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
 534         btrfs_set_stack_timespec_sec(&root_item.otime, cur_time.tv_sec);
 535         btrfs_set_stack_timespec_nsec(&root_item.otime, cur_time.tv_nsec);
 536         root_item.ctime = root_item.otime;
 537         btrfs_set_root_ctransid(&root_item, trans->transid);
 538         btrfs_set_root_otransid(&root_item, trans->transid);
 539
 540         btrfs_tree_unlock(leaf);
 541         free_extent_buffer(leaf);
 542         leaf = NULL;
 543
 544         btrfs_set_root_dirid(&root_item, new_dirid);
 545
 546         key.objectid = objectid;
 547         key.offset = 0;
 548         key.type = BTRFS_ROOT_ITEM_KEY;
 549         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 550                                 &root_item);
 551         if (ret)
 552                 goto fail;
 553
 554         key.offset = (u64)-1;
 555         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 556         if (IS_ERR(new_root)) {
 557                 ret = PTR_ERR(new_root);
 558                 btrfs_abort_transaction(trans, root, ret);
 559                 goto fail;
 560         }
 561
 562         btrfs_record_root_in_trans(trans, new_root);
 563
 564         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 565         if (ret) {
 566                 /* We potentially lose an unused inode item here */
 567                 btrfs_abort_transaction(trans, root, ret);
 568                 goto fail;
 569         }
 570
 571         /*
 572          * insert the directory item
 573          */
 574         ret = btrfs_set_inode_index(dir, &index);
 575         if (ret) {
 576                 btrfs_abort_transaction(trans, root, ret);
 577                 goto fail;
 578         }
 579
 580         ret = btrfs_insert_dir_item(trans, root,
 581                                     name, namelen, dir, &key,
 582                                     BTRFS_FT_DIR, index);
 583         if (ret) {
 584                 btrfs_abort_transaction(trans, root, ret);
 585                 goto fail;
 586         }
 587
 588         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 589         ret = btrfs_update_inode(trans, root, dir);
 590         BUG_ON(ret);
 591
 592         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 593                                  objectid, root->root_key.objectid,
 594                                  btrfs_ino(dir), index, name, namelen);
 595         BUG_ON(ret);
 596
 597         ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
 598                                   root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
 599                                   objectid);
 600         if (ret)
 601                 btrfs_abort_transaction(trans, root, ret);
 602
 603 fail:
 604         trans->block_rsv = NULL;
 605         trans->bytes_reserved = 0;
 606         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
 607
 608         if (async_transid) {
 609                 *async_transid = trans->transid;
 610                 err = btrfs_commit_transaction_async(trans, root, 1);
 611                 if (err)
 612                         err = btrfs_commit_transaction(trans, root);
 613         } else {
 614                 err = btrfs_commit_transaction(trans, root);
 615         }
 616         if (err && !ret)
 617                 ret = err;
 618
 619         if (!ret) {
 620                 inode = btrfs_lookup_dentry(dir, dentry);
 621                 if (IS_ERR(inode))
 622                         return PTR_ERR(inode);
 623                 d_instantiate(dentry, inode);
 624         }
 625         return ret;
 626 }
 627
 628 static void btrfs_wait_for_no_snapshoting_writes(struct btrfs_root *root)
 629 {
 630         s64 writers;
 631         DEFINE_WAIT(wait);
 632
 633         do {
 634                 prepare_to_wait(&root->subv_writers->wait, &wait,
 635                                 TASK_UNINTERRUPTIBLE);
 636
 637                 writers = percpu_counter_sum(&root->subv_writers->counter);
 638                 if (writers)
 639                         schedule();
 640
 641                 finish_wait(&root->subv_writers->wait, &wait);
 642         } while (writers);
 643 }
 644
 645 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 646                            struct dentry *dentry, char *name, int namelen,
 647                            u64 *async_transid, bool readonly,
 648                            struct btrfs_qgroup_inherit *inherit)
 649 {
 650         struct inode *inode;
 651         struct btrfs_pending_snapshot *pending_snapshot;
 652         struct btrfs_trans_handle *trans;
 653         int ret;
 654
 655         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 656                 return -EINVAL;
 657
 658         atomic_inc(&root->will_be_snapshoted);
 659         smp_mb__after_atomic();
 660         btrfs_wait_for_no_snapshoting_writes(root);
 661
 662         ret = btrfs_start_delalloc_inodes(root, 0);
 663         if (ret)
 664                 goto out;
 665
 666         btrfs_wait_ordered_extents(root, -1);
 667
 668         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 669         if (!pending_snapshot) {
 670                 ret = -ENOMEM;
 671                 goto out;
 672         }
 673
 674         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 675                              BTRFS_BLOCK_RSV_TEMP);
 676         /*
 677          * 1 - parent dir inode
 678          * 2 - dir entries
 679          * 1 - root item
 680          * 2 - root ref/backref
 681          * 1 - root of snapshot
 682          * 1 - UUID item
 683          */
 684         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 685                                         &pending_snapshot->block_rsv, 8,
 686                                         &pending_snapshot->qgroup_reserved,
 687                                         false);
 688         if (ret)
 689                 goto free;
 690
 691         pending_snapshot->dentry = dentry;
 692         pending_snapshot->root = root;
 693         pending_snapshot->readonly = readonly;
 694         pending_snapshot->dir = dir;
 695         pending_snapshot->inherit = inherit;
 696
 697         trans = btrfs_start_transaction(root, 0);
 698         if (IS_ERR(trans)) {
 699                 ret = PTR_ERR(trans);
 700                 goto fail;
 701         }
 702
 703         spin_lock(&root->fs_info->trans_lock);
 704         list_add(&pending_snapshot->list,
 705                  &trans->transaction->pending_snapshots);
 706         spin_unlock(&root->fs_info->trans_lock);
 707         if (async_transid) {
 708                 *async_transid = trans->transid;
 709                 ret = btrfs_commit_transaction_async(trans,
 710                                      root->fs_info->extent_root, 1);
 711                 if (ret)
 712                         ret = btrfs_commit_transaction(trans, root);
 713         } else {
 714                 ret = btrfs_commit_transaction(trans,
 715                                                root->fs_info->extent_root);
 716         }
 717         if (ret)
 718                 goto fail;
 719
 720         ret = pending_snapshot->error;
 721         if (ret)
 722                 goto fail;
 723
 724         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 725         if (ret)
 726                 goto fail;
 727
 728         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 729         if (IS_ERR(inode)) {
 730                 ret = PTR_ERR(inode);
 731                 goto fail;
 732         }
 733
 734         d_instantiate(dentry, inode);
 735         ret = 0;
 736 fail:
 737         btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,
 738                                          &pending_snapshot->block_rsv,
 739                                          pending_snapshot->qgroup_reserved);
 740 free:
 741         kfree(pending_snapshot);
 742 out:
 743         if (atomic_dec_and_test(&root->will_be_snapshoted))
 744                 wake_up_atomic_t(&root->will_be_snapshoted);
 745         return ret;
 746 }
 747
 748 /*  copy of may_delete in fs/namei.c()
 749  *      Check whether we can remove a link victim from directory dir, check
 750  *  whether the type of victim is right.
 751  *  1. We can't do it if dir is read-only (done in permission())
 752  *  2. We should have write and exec permissions on dir
 753  *  3. We can't remove anything from append-only dir
 754  *  4. We can't do anything with immutable dir (done in permission())
 755  *  5. If the sticky bit on dir is set we should either
 756  *      a. be owner of dir, or
 757  *      b. be owner of victim, or
 758  *      c. have CAP_FOWNER capability
 759  *  6. If the victim is append-only or immutable we can't do antyhing with
 760  *     links pointing to it.
 761  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 762  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 763  *  9. We can't remove a root or mountpoint.
 764  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 765  *     nfs_async_unlink().
 766  */
 767
 768 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 769 {
 770         int error;
 771
 772         if (d_really_is_negative(victim))
 773                 return -ENOENT;
 774
 775         BUG_ON(d_inode(victim->d_parent) != dir);
 776         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 777
 778         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 779         if (error)
 780                 return error;
 781         if (IS_APPEND(dir))
 782                 return -EPERM;
 783         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 784             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 785                 return -EPERM;
 786         if (isdir) {
 787                 if (!d_is_dir(victim))
 788                         return -ENOTDIR;
 789                 if (IS_ROOT(victim))
 790                         return -EBUSY;
 791         } else if (d_is_dir(victim))
 792                 return -EISDIR;
 793         if (IS_DEADDIR(dir))
 794                 return -ENOENT;
 795         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 796                 return -EBUSY;
 797         return 0;
 798 }
 799
 800 /* copy of may_create in fs/namei.c() */
 801 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 802 {
 803         if (d_really_is_positive(child))
 804                 return -EEXIST;
 805         if (IS_DEADDIR(dir))
 806                 return -ENOENT;
 807         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 808 }
 809
 810 /*
 811  * Create a new subvolume below @parent.  This is largely modeled after
 812  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 813  * inside this filesystem so it's quite a bit simpler.
 814  */
 815 static noinline int btrfs_mksubvol(struct path *parent,
 816                                    char *name, int namelen,
 817                                    struct btrfs_root *snap_src,
 818                                    u64 *async_transid, bool readonly,
 819                                    struct btrfs_qgroup_inherit *inherit)
 820 {
 821         struct inode *dir  = d_inode(parent->dentry);
 822         struct dentry *dentry;
 823         int error;
 824
 825         error = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
 826         if (error == -EINTR)
 827                 return error;
 828
 829         dentry = lookup_one_len(name, parent->dentry, namelen);
 830         error = PTR_ERR(dentry);
 831         if (IS_ERR(dentry))
 832                 goto out_unlock;
 833
 834         error = -EEXIST;
 835         if (d_really_is_positive(dentry))
 836                 goto out_dput;
 837
 838         error = btrfs_may_create(dir, dentry);
 839         if (error)
 840                 goto out_dput;
 841
 842         /*
 843          * even if this name doesn't exist, we may get hash collisions.
 844          * check for them now when we can safely fail
 845          */
 846         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 847                                                dir->i_ino, name,
 848                                                namelen);
 849         if (error)
 850                 goto out_dput;
 851
 852         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 853
 854         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 855                 goto out_up_read;
 856
 857         if (snap_src) {
 858                 error = create_snapshot(snap_src, dir, dentry, name, namelen,
 859                                         async_transid, readonly, inherit);
 860         } else {
 861                 error = create_subvol(dir, dentry, name, namelen,
 862                                       async_transid, inherit);
 863         }
 864         if (!error)
 865                 fsnotify_mkdir(dir, dentry);
 866 out_up_read:
 867         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 868 out_dput:
 869         dput(dentry);
 870 out_unlock:
 871         mutex_unlock(&dir->i_mutex);
 872         return error;
 873 }
 874
 875 /*
 876  * When we're defragging a range, we don't want to kick it off again
 877  * if it is really just waiting for delalloc to send it down.
 878  * If we find a nice big extent or delalloc range for the bytes in the
 879  * file you want to defrag, we return 0 to let you know to skip this
 880  * part of the file
 881  */
 882 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 883 {
 884         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 885         struct extent_map *em = NULL;
 886         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 887         u64 end;
 888
 889         read_lock(&em_tree->lock);
 890         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 891         read_unlock(&em_tree->lock);
 892
 893         if (em) {
 894                 end = extent_map_end(em);
 895                 free_extent_map(em);
 896                 if (end - offset > thresh)
 897                         return 0;
 898         }
 899         /* if we already have a nice delalloc here, just stop */
 900         thresh /= 2;
 901         end = count_range_bits(io_tree, &offset, offset + thresh,
 902                                thresh, EXTENT_DELALLOC, 1);
 903         if (end >= thresh)
 904                 return 0;
 905         return 1;
 906 }
 907
 908 /*
 909  * helper function to walk through a file and find extents
 910  * newer than a specific transid, and smaller than thresh.
 911  *
 912  * This is used by the defragging code to find new and small
 913  * extents
 914  */
 915 static int find_new_extents(struct btrfs_root *root,
 916                             struct inode *inode, u64 newer_than,
 917                             u64 *off, u32 thresh)
 918 {
 919         struct btrfs_path *path;
 920         struct btrfs_key min_key;
 921         struct extent_buffer *leaf;
 922         struct btrfs_file_extent_item *extent;
 923         int type;
 924         int ret;
 925         u64 ino = btrfs_ino(inode);
 926
 927         path = btrfs_alloc_path();
 928         if (!path)
 929                 return -ENOMEM;
 930
 931         min_key.objectid = ino;
 932         min_key.type = BTRFS_EXTENT_DATA_KEY;
 933         min_key.offset = *off;
 934
 935         while (1) {
 936                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 937                 if (ret != 0)
 938                         goto none;
 939 process_slot:
 940                 if (min_key.objectid != ino)
 941                         goto none;
 942                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 943                         goto none;
 944
 945                 leaf = path->nodes[0];
 946                 extent = btrfs_item_ptr(leaf, path->slots[0],
 947                                         struct btrfs_file_extent_item);
 948
 949                 type = btrfs_file_extent_type(leaf, extent);
 950                 if (type == BTRFS_FILE_EXTENT_REG &&
 951                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 952                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 953                         *off = min_key.offset;
 954                         btrfs_free_path(path);
 955                         return 0;
 956                 }
 957
 958                 path->slots[0]++;
 959                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
 960                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 961                         goto process_slot;
 962                 }
 963
 964                 if (min_key.offset == (u64)-1)
 965                         goto none;
 966
 967                 min_key.offset++;
 968                 btrfs_release_path(path);
 969         }
 970 none:
 971         btrfs_free_path(path);
 972         return -ENOENT;
 973 }
 974
 975 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 976 {
 977         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 978         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 979         struct extent_map *em;
 980         u64 len = PAGE_CACHE_SIZE;
 981
 982         /*
 983          * hopefully we have this extent in the tree already, try without
 984          * the full extent lock
 985          */
 986         read_lock(&em_tree->lock);
 987         em = lookup_extent_mapping(em_tree, start, len);
 988         read_unlock(&em_tree->lock);
 989
 990         if (!em) {
 991                 struct extent_state *cached = NULL;
 992                 u64 end = start + len - 1;
 993
 994                 /* get the big lock and read metadata off disk */
 995                 lock_extent_bits(io_tree, start, end, 0, &cached);
 996                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 997                 unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
 998
 999                 if (IS_ERR(em))
1000                         return NULL;
1001         }
1002
1003         return em;
1004 }
1005
1006 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1007 {
1008         struct extent_map *next;
1009         bool ret = true;
1010
1011         /* this is the last extent */
1012         if (em->start + em->len >= i_size_read(inode))
1013                 return false;
1014
1015         next = defrag_lookup_extent(inode, em->start + em->len);
1016         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1017                 ret = false;
1018         else if ((em->block_start + em->block_len == next->block_start) &&
1019                  (em->block_len > 128 * 1024 && next->block_len > 128 * 1024))
1020                 ret = false;
1021
1022         free_extent_map(next);
1023         return ret;
1024 }
1025
1026 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1027                                u64 *last_len, u64 *skip, u64 *defrag_end,
1028                                int compress)
1029 {
1030         struct extent_map *em;
1031         int ret = 1;
1032         bool next_mergeable = true;
1033
1034         /*
1035          * make sure that once we start defragging an extent, we keep on
1036          * defragging it
1037          */
1038         if (start < *defrag_end)
1039                 return 1;
1040
1041         *skip = 0;
1042
1043         em = defrag_lookup_extent(inode, start);
1044         if (!em)
1045                 return 0;
1046
1047         /* this will cover holes, and inline extents */
1048         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1049                 ret = 0;
1050                 goto out;
1051         }
1052
1053         next_mergeable = defrag_check_next_extent(inode, em);
1054         /*
1055          * we hit a real extent, if it is big or the next extent is not a
1056          * real extent, don't bother defragging it
1057          */
1058         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1059             (em->len >= thresh || !next_mergeable))
1060                 ret = 0;
1061 out:
1062         /*
1063          * last_len ends up being a counter of how many bytes we've defragged.
1064          * every time we choose not to defrag an extent, we reset *last_len
1065          * so that the next tiny extent will force a defrag.
1066          *
1067          * The end result of this is that tiny extents before a single big
1068          * extent will force at least part of that big extent to be defragged.
1069          */
1070         if (ret) {
1071                 *defrag_end = extent_map_end(em);
1072         } else {
1073                 *last_len = 0;
1074                 *skip = extent_map_end(em);
1075                 *defrag_end = 0;
1076         }
1077
1078         free_extent_map(em);
1079         return ret;
1080 }
1081
1082 /*
1083  * it doesn't do much good to defrag one or two pages
1084  * at a time.  This pulls in a nice chunk of pages
1085  * to COW and defrag.
1086  *
1087  * It also makes sure the delalloc code has enough
1088  * dirty data to avoid making new small extents as part
1089  * of the defrag
1090  *
1091  * It's a good idea to start RA on this range
1092  * before calling this.
1093  */
1094 static int cluster_pages_for_defrag(struct inode *inode,
1095                                     struct page **pages,
1096                                     unsigned long start_index,
1097                                     unsigned long num_pages)
1098 {
1099         unsigned long file_end;
1100         u64 isize = i_size_read(inode);
1101         u64 page_start;
1102         u64 page_end;
1103         u64 page_cnt;
1104         int ret;
1105         int i;
1106         int i_done;
1107         struct btrfs_ordered_extent *ordered;
1108         struct extent_state *cached_state = NULL;
1109         struct extent_io_tree *tree;
1110         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1111
1112         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
1113         if (!isize || start_index > file_end)
1114                 return 0;
1115
1116         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1117
1118         ret = btrfs_delalloc_reserve_space(inode,
1119                                            page_cnt << PAGE_CACHE_SHIFT);
1120         if (ret)
1121                 return ret;
1122         i_done = 0;
1123         tree = &BTRFS_I(inode)->io_tree;
1124
1125         /* step one, lock all the pages */
1126         for (i = 0; i < page_cnt; i++) {
1127                 struct page *page;
1128 again:
1129                 page = find_or_create_page(inode->i_mapping,
1130                                            start_index + i, mask);
1131                 if (!page)
1132                         break;
1133
1134                 page_start = page_offset(page);
1135                 page_end = page_start + PAGE_CACHE_SIZE - 1;
1136                 while (1) {
1137                         lock_extent_bits(tree, page_start, page_end,
1138                                          0, &cached_state);
1139                         ordered = btrfs_lookup_ordered_extent(inode,
1140                                                               page_start);
1141                         unlock_extent_cached(tree, page_start, page_end,
1142                                              &cached_state, GFP_NOFS);
1143                         if (!ordered)
1144                                 break;
1145
1146                         unlock_page(page);
1147                         btrfs_start_ordered_extent(inode, ordered, 1);
1148                         btrfs_put_ordered_extent(ordered);
1149                         lock_page(page);
1150                         /*
1151                          * we unlocked the page above, so we need check if
1152                          * it was released or not.
1153                          */
1154                         if (page->mapping != inode->i_mapping) {
1155                                 unlock_page(page);
1156                                 page_cache_release(page);
1157                                 goto again;
1158                         }
1159                 }
1160
1161                 if (!PageUptodate(page)) {
1162                         btrfs_readpage(NULL, page);
1163                         lock_page(page);
1164                         if (!PageUptodate(page)) {
1165                                 unlock_page(page);
1166                                 page_cache_release(page);
1167                                 ret = -EIO;
1168                                 break;
1169                         }
1170                 }
1171
1172                 if (page->mapping != inode->i_mapping) {
1173                         unlock_page(page);
1174                         page_cache_release(page);
1175                         goto again;
1176                 }
1177
1178                 pages[i] = page;
1179                 i_done++;
1180         }
1181         if (!i_done || ret)
1182                 goto out;
1183
1184         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1185                 goto out;
1186
1187         /*
1188          * so now we have a nice long stream of locked
1189          * and up to date pages, lets wait on them
1190          */
1191         for (i = 0; i < i_done; i++)
1192                 wait_on_page_writeback(pages[i]);
1193
1194         page_start = page_offset(pages[0]);
1195         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1196
1197         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1198                          page_start, page_end - 1, 0, &cached_state);
1199         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1200                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1201                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1202                           &cached_state, GFP_NOFS);
1203
1204         if (i_done != page_cnt) {
1205                 spin_lock(&BTRFS_I(inode)->lock);
1206                 BTRFS_I(inode)->outstanding_extents++;
1207                 spin_unlock(&BTRFS_I(inode)->lock);
1208                 btrfs_delalloc_release_space(inode,
1209                                      (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1210         }
1211
1212
1213         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1214                           &cached_state, GFP_NOFS);
1215
1216         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1217                              page_start, page_end - 1, &cached_state,
1218                              GFP_NOFS);
1219
1220         for (i = 0; i < i_done; i++) {
1221                 clear_page_dirty_for_io(pages[i]);
1222                 ClearPageChecked(pages[i]);
1223                 set_page_extent_mapped(pages[i]);
1224                 set_page_dirty(pages[i]);
1225                 unlock_page(pages[i]);
1226                 page_cache_release(pages[i]);
1227         }
1228         return i_done;
1229 out:
1230         for (i = 0; i < i_done; i++) {
1231                 unlock_page(pages[i]);
1232                 page_cache_release(pages[i]);
1233         }
1234         btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1235         return ret;
1236
1237 }
1238
1239 int btrfs_defrag_file(struct inode *inode, struct file *file,
1240                       struct btrfs_ioctl_defrag_range_args *range,
1241                       u64 newer_than, unsigned long max_to_defrag)
1242 {
1243         struct btrfs_root *root = BTRFS_I(inode)->root;
1244         struct file_ra_state *ra = NULL;
1245         unsigned long last_index;
1246         u64 isize = i_size_read(inode);
1247         u64 last_len = 0;
1248         u64 skip = 0;
1249         u64 defrag_end = 0;
1250         u64 newer_off = range->start;
1251         unsigned long i;
1252         unsigned long ra_index = 0;
1253         int ret;
1254         int defrag_count = 0;
1255         int compress_type = BTRFS_COMPRESS_ZLIB;
1256         u32 extent_thresh = range->extent_thresh;
1257         unsigned long max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1258         unsigned long cluster = max_cluster;
1259         u64 new_align = ~((u64)128 * 1024 - 1);
1260         struct page **pages = NULL;
1261
1262         if (isize == 0)
1263                 return 0;
1264
1265         if (range->start >= isize)
1266                 return -EINVAL;
1267
1268         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1269                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1270                         return -EINVAL;
1271                 if (range->compress_type)
1272                         compress_type = range->compress_type;
1273         }
1274
1275         if (extent_thresh == 0)
1276                 extent_thresh = 256 * 1024;
1277
1278         /*
1279          * if we were not given a file, allocate a readahead
1280          * context
1281          */
1282         if (!file) {
1283                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1284                 if (!ra)
1285                         return -ENOMEM;
1286                 file_ra_state_init(ra, inode->i_mapping);
1287         } else {
1288                 ra = &file->f_ra;
1289         }
1290
1291         pages = kmalloc_array(max_cluster, sizeof(struct page *),
1292                         GFP_NOFS);
1293         if (!pages) {
1294                 ret = -ENOMEM;
1295                 goto out_ra;
1296         }
1297
1298         /* find the last page to defrag */
1299         if (range->start + range->len > range->start) {
1300                 last_index = min_t(u64, isize - 1,
1301                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1302         } else {
1303                 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1304         }
1305
1306         if (newer_than) {
1307                 ret = find_new_extents(root, inode, newer_than,
1308                                        &newer_off, 64 * 1024);
1309                 if (!ret) {
1310                         range->start = newer_off;
1311                         /*
1312                          * we always align our defrag to help keep
1313                          * the extents in the file evenly spaced
1314                          */
1315                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1316                 } else
1317                         goto out_ra;
1318         } else {
1319                 i = range->start >> PAGE_CACHE_SHIFT;
1320         }
1321         if (!max_to_defrag)
1322                 max_to_defrag = last_index - i + 1;
1323
1324         /*
1325          * make writeback starts from i, so the defrag range can be
1326          * written sequentially.
1327          */
1328         if (i < inode->i_mapping->writeback_index)
1329                 inode->i_mapping->writeback_index = i;
1330
1331         while (i <= last_index && defrag_count < max_to_defrag &&
1332                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE))) {
1333                 /*
1334                  * make sure we stop running if someone unmounts
1335                  * the FS
1336                  */
1337                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1338                         break;
1339
1340                 if (btrfs_defrag_cancelled(root->fs_info)) {
1341                         printk(KERN_DEBUG "BTRFS: defrag_file cancelled\n");
1342                         ret = -EAGAIN;
1343                         break;
1344                 }
1345
1346                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1347                                          extent_thresh, &last_len, &skip,
1348                                          &defrag_end, range->flags &
1349                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1350                         unsigned long next;
1351                         /*
1352                          * the should_defrag function tells us how much to skip
1353                          * bump our counter by the suggested amount
1354                          */
1355                         next = DIV_ROUND_UP(skip, PAGE_CACHE_SIZE);
1356                         i = max(i + 1, next);
1357                         continue;
1358                 }
1359
1360                 if (!newer_than) {
1361                         cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1362                                    PAGE_CACHE_SHIFT) - i;
1363                         cluster = min(cluster, max_cluster);
1364                 } else {
1365                         cluster = max_cluster;
1366                 }
1367
1368                 if (i + cluster > ra_index) {
1369                         ra_index = max(i, ra_index);
1370                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1371                                        cluster);
1372                         ra_index += cluster;
1373                 }
1374
1375                 mutex_lock(&inode->i_mutex);
1376                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1377                         BTRFS_I(inode)->force_compress = compress_type;
1378                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1379                 if (ret < 0) {
1380                         mutex_unlock(&inode->i_mutex);
1381                         goto out_ra;
1382                 }
1383
1384                 defrag_count += ret;
1385                 balance_dirty_pages_ratelimited(inode->i_mapping);
1386                 mutex_unlock(&inode->i_mutex);
1387
1388                 if (newer_than) {
1389                         if (newer_off == (u64)-1)
1390                                 break;
1391
1392                         if (ret > 0)
1393                                 i += ret;
1394
1395                         newer_off = max(newer_off + 1,
1396                                         (u64)i << PAGE_CACHE_SHIFT);
1397
1398                         ret = find_new_extents(root, inode,
1399                                                newer_than, &newer_off,
1400                                                64 * 1024);
1401                         if (!ret) {
1402                                 range->start = newer_off;
1403                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1404                         } else {
1405                                 break;
1406                         }
1407                 } else {
1408                         if (ret > 0) {
1409                                 i += ret;
1410                                 last_len += ret << PAGE_CACHE_SHIFT;
1411                         } else {
1412                                 i++;
1413                                 last_len = 0;
1414                         }
1415                 }
1416         }
1417
1418         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1419                 filemap_flush(inode->i_mapping);
1420                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1421                              &BTRFS_I(inode)->runtime_flags))
1422                         filemap_flush(inode->i_mapping);
1423         }
1424
1425         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1426                 /* the filemap_flush will queue IO into the worker threads, but
1427                  * we have to make sure the IO is actually started and that
1428                  * ordered extents get created before we return
1429                  */
1430                 atomic_inc(&root->fs_info->async_submit_draining);
1431                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1432                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1433                         wait_event(root->fs_info->async_submit_wait,
1434                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1435                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1436                 }
1437                 atomic_dec(&root->fs_info->async_submit_draining);
1438         }
1439
1440         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1441                 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1442         }
1443
1444         ret = defrag_count;
1445
1446 out_ra:
1447         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1448                 mutex_lock(&inode->i_mutex);
1449                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1450                 mutex_unlock(&inode->i_mutex);
1451         }
1452         if (!file)
1453                 kfree(ra);
1454         kfree(pages);
1455         return ret;
1456 }
1457
1458 static noinline int btrfs_ioctl_resize(struct file *file,
1459                                         void __user *arg)
1460 {
1461         u64 new_size;
1462         u64 old_size;
1463         u64 devid = 1;
1464         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
1465         struct btrfs_ioctl_vol_args *vol_args;
1466         struct btrfs_trans_handle *trans;
1467         struct btrfs_device *device = NULL;
1468         char *sizestr;
1469         char *retptr;
1470         char *devstr = NULL;
1471         int ret = 0;
1472         int mod = 0;
1473
1474         if (!capable(CAP_SYS_ADMIN))
1475                 return -EPERM;
1476
1477         ret = mnt_want_write_file(file);
1478         if (ret)
1479                 return ret;
1480
1481         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1482                         1)) {
1483                 mnt_drop_write_file(file);
1484                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1485         }
1486
1487         mutex_lock(&root->fs_info->volume_mutex);
1488         vol_args = memdup_user(arg, sizeof(*vol_args));
1489         if (IS_ERR(vol_args)) {
1490                 ret = PTR_ERR(vol_args);
1491                 goto out;
1492         }
1493
1494         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1495
1496         sizestr = vol_args->name;
1497         devstr = strchr(sizestr, ':');
1498         if (devstr) {
1499                 sizestr = devstr + 1;
1500                 *devstr = '\0';
1501                 devstr = vol_args->name;
1502                 ret = kstrtoull(devstr, 10, &devid);
1503                 if (ret)
1504                         goto out_free;
1505                 if (!devid) {
1506                         ret = -EINVAL;
1507                         goto out_free;
1508                 }
1509                 btrfs_info(root->fs_info, "resizing devid %llu", devid);
1510         }
1511
1512         device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1513         if (!device) {
1514                 btrfs_info(root->fs_info, "resizer unable to find device %llu",
1515                        devid);
1516                 ret = -ENODEV;
1517                 goto out_free;
1518         }
1519
1520         if (!device->writeable) {
1521                 btrfs_info(root->fs_info,
1522                            "resizer unable to apply on readonly device %llu",
1523                        devid);
1524                 ret = -EPERM;
1525                 goto out_free;
1526         }
1527
1528         if (!strcmp(sizestr, "max"))
1529                 new_size = device->bdev->bd_inode->i_size;
1530         else {
1531                 if (sizestr[0] == '-') {
1532                         mod = -1;
1533                         sizestr++;
1534                 } else if (sizestr[0] == '+') {
1535                         mod = 1;
1536                         sizestr++;
1537                 }
1538                 new_size = memparse(sizestr, &retptr);
1539                 if (*retptr != '\0' || new_size == 0) {
1540                         ret = -EINVAL;
1541                         goto out_free;
1542                 }
1543         }
1544
1545         if (device->is_tgtdev_for_dev_replace) {
1546                 ret = -EPERM;
1547                 goto out_free;
1548         }
1549
1550         old_size = btrfs_device_get_total_bytes(device);
1551
1552         if (mod < 0) {
1553                 if (new_size > old_size) {
1554                         ret = -EINVAL;
1555                         goto out_free;
1556                 }
1557                 new_size = old_size - new_size;
1558         } else if (mod > 0) {
1559                 if (new_size > ULLONG_MAX - old_size) {
1560                         ret = -ERANGE;
1561                         goto out_free;
1562                 }
1563                 new_size = old_size + new_size;
1564         }
1565
1566         if (new_size < 256 * 1024 * 1024) {
1567                 ret = -EINVAL;
1568                 goto out_free;
1569         }
1570         if (new_size > device->bdev->bd_inode->i_size) {
1571                 ret = -EFBIG;
1572                 goto out_free;
1573         }
1574
1575         new_size = div_u64(new_size, root->sectorsize);
1576         new_size *= root->sectorsize;
1577
1578         printk_in_rcu(KERN_INFO "BTRFS: new size for %s is %llu\n",
1579                       rcu_str_deref(device->name), new_size);
1580
1581         if (new_size > old_size) {
1582                 trans = btrfs_start_transaction(root, 0);
1583                 if (IS_ERR(trans)) {
1584                         ret = PTR_ERR(trans);
1585                         goto out_free;
1586                 }
1587                 ret = btrfs_grow_device(trans, device, new_size);
1588                 btrfs_commit_transaction(trans, root);
1589         } else if (new_size < old_size) {
1590                 ret = btrfs_shrink_device(device, new_size);
1591         } /* equal, nothing need to do */
1592
1593 out_free:
1594         kfree(vol_args);
1595 out:
1596         mutex_unlock(&root->fs_info->volume_mutex);
1597         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1598         mnt_drop_write_file(file);
1599         return ret;
1600 }
1601
1602 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1603                                 char *name, unsigned long fd, int subvol,
1604                                 u64 *transid, bool readonly,
1605                                 struct btrfs_qgroup_inherit *inherit)
1606 {
1607         int namelen;
1608         int ret = 0;
1609
1610         ret = mnt_want_write_file(file);
1611         if (ret)
1612                 goto out;
1613
1614         namelen = strlen(name);
1615         if (strchr(name, '/')) {
1616                 ret = -EINVAL;
1617                 goto out_drop_write;
1618         }
1619
1620         if (name[0] == '.' &&
1621            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1622                 ret = -EEXIST;
1623                 goto out_drop_write;
1624         }
1625
1626         if (subvol) {
1627                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1628                                      NULL, transid, readonly, inherit);
1629         } else {
1630                 struct fd src = fdget(fd);
1631                 struct inode *src_inode;
1632                 if (!src.file) {
1633                         ret = -EINVAL;
1634                         goto out_drop_write;
1635                 }
1636
1637                 src_inode = file_inode(src.file);
1638                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1639                         btrfs_info(BTRFS_I(src_inode)->root->fs_info,
1640                                    "Snapshot src from another FS");
1641                         ret = -EXDEV;
1642                 } else if (!inode_owner_or_capable(src_inode)) {
1643                         /*
1644                          * Subvolume creation is not restricted, but snapshots
1645                          * are limited to own subvolumes only
1646                          */
1647                         ret = -EPERM;
1648                 } else {
1649                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1650                                              BTRFS_I(src_inode)->root,
1651                                              transid, readonly, inherit);
1652                 }
1653                 fdput(src);
1654         }
1655 out_drop_write:
1656         mnt_drop_write_file(file);
1657 out:
1658         return ret;
1659 }
1660
1661 static noinline int btrfs_ioctl_snap_create(struct file *file,
1662                                             void __user *arg, int subvol)
1663 {
1664         struct btrfs_ioctl_vol_args *vol_args;
1665         int ret;
1666
1667         vol_args = memdup_user(arg, sizeof(*vol_args));
1668         if (IS_ERR(vol_args))
1669                 return PTR_ERR(vol_args);
1670         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1671
1672         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1673                                               vol_args->fd, subvol,
1674                                               NULL, false, NULL);
1675
1676         kfree(vol_args);
1677         return ret;
1678 }
1679
1680 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1681                                                void __user *arg, int subvol)
1682 {
1683         struct btrfs_ioctl_vol_args_v2 *vol_args;
1684         int ret;
1685         u64 transid = 0;
1686         u64 *ptr = NULL;
1687         bool readonly = false;
1688         struct btrfs_qgroup_inherit *inherit = NULL;
1689
1690         vol_args = memdup_user(arg, sizeof(*vol_args));
1691         if (IS_ERR(vol_args))
1692                 return PTR_ERR(vol_args);
1693         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1694
1695         if (vol_args->flags &
1696             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1697               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1698                 ret = -EOPNOTSUPP;
1699                 goto free_args;
1700         }
1701
1702         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1703                 ptr = &transid;
1704         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1705                 readonly = true;
1706         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1707                 if (vol_args->size > PAGE_CACHE_SIZE) {
1708                         ret = -EINVAL;
1709                         goto free_args;
1710                 }
1711                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1712                 if (IS_ERR(inherit)) {
1713                         ret = PTR_ERR(inherit);
1714                         goto free_args;
1715                 }
1716         }
1717
1718         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1719                                               vol_args->fd, subvol, ptr,
1720                                               readonly, inherit);
1721         if (ret)
1722                 goto free_inherit;
1723
1724         if (ptr && copy_to_user(arg +
1725                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1726                                         transid),
1727                                 ptr, sizeof(*ptr)))
1728                 ret = -EFAULT;
1729
1730 free_inherit:
1731         kfree(inherit);
1732 free_args:
1733         kfree(vol_args);
1734         return ret;
1735 }
1736
1737 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1738                                                 void __user *arg)
1739 {
1740         struct inode *inode = file_inode(file);
1741         struct btrfs_root *root = BTRFS_I(inode)->root;
1742         int ret = 0;
1743         u64 flags = 0;
1744
1745         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1746                 return -EINVAL;
1747
1748         down_read(&root->fs_info->subvol_sem);
1749         if (btrfs_root_readonly(root))
1750                 flags |= BTRFS_SUBVOL_RDONLY;
1751         up_read(&root->fs_info->subvol_sem);
1752
1753         if (copy_to_user(arg, &flags, sizeof(flags)))
1754                 ret = -EFAULT;
1755
1756         return ret;
1757 }
1758
1759 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1760                                               void __user *arg)
1761 {
1762         struct inode *inode = file_inode(file);
1763         struct btrfs_root *root = BTRFS_I(inode)->root;
1764         struct btrfs_trans_handle *trans;
1765         u64 root_flags;
1766         u64 flags;
1767         int ret = 0;
1768
1769         if (!inode_owner_or_capable(inode))
1770                 return -EPERM;
1771
1772         ret = mnt_want_write_file(file);
1773         if (ret)
1774                 goto out;
1775
1776         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1777                 ret = -EINVAL;
1778                 goto out_drop_write;
1779         }
1780
1781         if (copy_from_user(&flags, arg, sizeof(flags))) {
1782                 ret = -EFAULT;
1783                 goto out_drop_write;
1784         }
1785
1786         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1787                 ret = -EINVAL;
1788                 goto out_drop_write;
1789         }
1790
1791         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1792                 ret = -EOPNOTSUPP;
1793                 goto out_drop_write;
1794         }
1795
1796         down_write(&root->fs_info->subvol_sem);
1797
1798         /* nothing to do */
1799         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1800                 goto out_drop_sem;
1801
1802         root_flags = btrfs_root_flags(&root->root_item);
1803         if (flags & BTRFS_SUBVOL_RDONLY) {
1804                 btrfs_set_root_flags(&root->root_item,
1805                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1806         } else {
1807                 /*
1808                  * Block RO -> RW transition if this subvolume is involved in
1809                  * send
1810                  */
1811                 spin_lock(&root->root_item_lock);
1812                 if (root->send_in_progress == 0) {
1813                         btrfs_set_root_flags(&root->root_item,
1814                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1815                         spin_unlock(&root->root_item_lock);
1816                 } else {
1817                         spin_unlock(&root->root_item_lock);
1818                         btrfs_warn(root->fs_info,
1819                         "Attempt to set subvolume %llu read-write during send",
1820                                         root->root_key.objectid);
1821                         ret = -EPERM;
1822                         goto out_drop_sem;
1823                 }
1824         }
1825
1826         trans = btrfs_start_transaction(root, 1);
1827         if (IS_ERR(trans)) {
1828                 ret = PTR_ERR(trans);
1829                 goto out_reset;
1830         }
1831
1832         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1833                                 &root->root_key, &root->root_item);
1834
1835         btrfs_commit_transaction(trans, root);
1836 out_reset:
1837         if (ret)
1838                 btrfs_set_root_flags(&root->root_item, root_flags);
1839 out_drop_sem:
1840         up_write(&root->fs_info->subvol_sem);
1841 out_drop_write:
1842         mnt_drop_write_file(file);
1843 out:
1844         return ret;
1845 }
1846
1847 /*
1848  * helper to check if the subvolume references other subvolumes
1849  */
1850 static noinline int may_destroy_subvol(struct btrfs_root *root)
1851 {
1852         struct btrfs_path *path;
1853         struct btrfs_dir_item *di;
1854         struct btrfs_key key;
1855         u64 dir_id;
1856         int ret;
1857
1858         path = btrfs_alloc_path();
1859         if (!path)
1860                 return -ENOMEM;
1861
1862         /* Make sure this root isn't set as the default subvol */
1863         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
1864         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, path,
1865                                    dir_id, "default", 7, 0);
1866         if (di && !IS_ERR(di)) {
1867                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1868                 if (key.objectid == root->root_key.objectid) {
1869                         ret = -EPERM;
1870                         btrfs_err(root->fs_info, "deleting default subvolume "
1871                                   "%llu is not allowed", key.objectid);
1872                         goto out;
1873                 }
1874                 btrfs_release_path(path);
1875         }
1876
1877         key.objectid = root->root_key.objectid;
1878         key.type = BTRFS_ROOT_REF_KEY;
1879         key.offset = (u64)-1;
1880
1881         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1882                                 &key, path, 0, 0);
1883         if (ret < 0)
1884                 goto out;
1885         BUG_ON(ret == 0);
1886
1887         ret = 0;
1888         if (path->slots[0] > 0) {
1889                 path->slots[0]--;
1890                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1891                 if (key.objectid == root->root_key.objectid &&
1892                     key.type == BTRFS_ROOT_REF_KEY)
1893                         ret = -ENOTEMPTY;
1894         }
1895 out:
1896         btrfs_free_path(path);
1897         return ret;
1898 }
1899
1900 static noinline int key_in_sk(struct btrfs_key *key,
1901                               struct btrfs_ioctl_search_key *sk)
1902 {
1903         struct btrfs_key test;
1904         int ret;
1905
1906         test.objectid = sk->min_objectid;
1907         test.type = sk->min_type;
1908         test.offset = sk->min_offset;
1909
1910         ret = btrfs_comp_cpu_keys(key, &test);
1911         if (ret < 0)
1912                 return 0;
1913
1914         test.objectid = sk->max_objectid;
1915         test.type = sk->max_type;
1916         test.offset = sk->max_offset;
1917
1918         ret = btrfs_comp_cpu_keys(key, &test);
1919         if (ret > 0)
1920                 return 0;
1921         return 1;
1922 }
1923
1924 static noinline int copy_to_sk(struct btrfs_root *root,
1925                                struct btrfs_path *path,
1926                                struct btrfs_key *key,
1927                                struct btrfs_ioctl_search_key *sk,
1928                                size_t *buf_size,
1929                                char __user *ubuf,
1930                                unsigned long *sk_offset,
1931                                int *num_found)
1932 {
1933         u64 found_transid;
1934         struct extent_buffer *leaf;
1935         struct btrfs_ioctl_search_header sh;
1936         unsigned long item_off;
1937         unsigned long item_len;
1938         int nritems;
1939         int i;
1940         int slot;
1941         int ret = 0;
1942
1943         leaf = path->nodes[0];
1944         slot = path->slots[0];
1945         nritems = btrfs_header_nritems(leaf);
1946
1947         if (btrfs_header_generation(leaf) > sk->max_transid) {
1948                 i = nritems;
1949                 goto advance_key;
1950         }
1951         found_transid = btrfs_header_generation(leaf);
1952
1953         for (i = slot; i < nritems; i++) {
1954                 item_off = btrfs_item_ptr_offset(leaf, i);
1955                 item_len = btrfs_item_size_nr(leaf, i);
1956
1957                 btrfs_item_key_to_cpu(leaf, key, i);
1958                 if (!key_in_sk(key, sk))
1959                         continue;
1960
1961                 if (sizeof(sh) + item_len > *buf_size) {
1962                         if (*num_found) {
1963                                 ret = 1;
1964                                 goto out;
1965                         }
1966
1967                         /*
1968                          * return one empty item back for v1, which does not
1969                          * handle -EOVERFLOW
1970                          */
1971
1972                         *buf_size = sizeof(sh) + item_len;
1973                         item_len = 0;
1974                         ret = -EOVERFLOW;
1975                 }
1976
1977                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
1978                         ret = 1;
1979                         goto out;
1980                 }
1981
1982                 sh.objectid = key->objectid;
1983                 sh.offset = key->offset;
1984                 sh.type = key->type;
1985                 sh.len = item_len;
1986                 sh.transid = found_transid;
1987
1988                 /* copy search result header */
1989                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
1990                         ret = -EFAULT;
1991                         goto out;
1992                 }
1993
1994                 *sk_offset += sizeof(sh);
1995
1996                 if (item_len) {
1997                         char __user *up = ubuf + *sk_offset;
1998                         /* copy the item */
1999                         if (read_extent_buffer_to_user(leaf, up,
2000                                                        item_off, item_len)) {
2001                                 ret = -EFAULT;
2002                                 goto out;
2003                         }
2004
2005                         *sk_offset += item_len;
2006                 }
2007                 (*num_found)++;
2008
2009                 if (ret) /* -EOVERFLOW from above */
2010                         goto out;
2011
2012                 if (*num_found >= sk->nr_items) {
2013                         ret = 1;
2014                         goto out;
2015                 }
2016         }
2017 advance_key:
2018         ret = 0;
2019         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
2020                 key->offset++;
2021         else if (key->type < (u8)-1 && key->type < sk->max_type) {
2022                 key->offset = 0;
2023                 key->type++;
2024         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
2025                 key->offset = 0;
2026                 key->type = 0;
2027                 key->objectid++;
2028         } else
2029                 ret = 1;
2030 out:
2031         /*
2032          *  0: all items from this leaf copied, continue with next
2033          *  1: * more items can be copied, but unused buffer is too small
2034          *     * all items were found
2035          *     Either way, it will stops the loop which iterates to the next
2036          *     leaf
2037          *  -EOVERFLOW: item was to large for buffer
2038          *  -EFAULT: could not copy extent buffer back to userspace
2039          */
2040         return ret;
2041 }
2042
2043 static noinline int search_ioctl(struct inode *inode,
2044                                  struct btrfs_ioctl_search_key *sk,
2045                                  size_t *buf_size,
2046                                  char __user *ubuf)
2047 {
2048         struct btrfs_root *root;
2049         struct btrfs_key key;
2050         struct btrfs_path *path;
2051         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
2052         int ret;
2053         int num_found = 0;
2054         unsigned long sk_offset = 0;
2055
2056         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2057                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2058                 return -EOVERFLOW;
2059         }
2060
2061         path = btrfs_alloc_path();
2062         if (!path)
2063                 return -ENOMEM;
2064
2065         if (sk->tree_id == 0) {
2066                 /* search the root of the inode that was passed */
2067                 root = BTRFS_I(inode)->root;
2068         } else {
2069                 key.objectid = sk->tree_id;
2070                 key.type = BTRFS_ROOT_ITEM_KEY;
2071                 key.offset = (u64)-1;
2072                 root = btrfs_read_fs_root_no_name(info, &key);
2073                 if (IS_ERR(root)) {
2074                         printk(KERN_ERR "BTRFS: could not find root %llu\n",
2075                                sk->tree_id);
2076                         btrfs_free_path(path);
2077                         return -ENOENT;
2078                 }
2079         }
2080
2081         key.objectid = sk->min_objectid;
2082         key.type = sk->min_type;
2083         key.offset = sk->min_offset;
2084
2085         while (1) {
2086                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2087                 if (ret != 0) {
2088                         if (ret > 0)
2089                                 ret = 0;
2090                         goto err;
2091                 }
2092                 ret = copy_to_sk(root, path, &key, sk, buf_size, ubuf,
2093                                  &sk_offset, &num_found);
2094                 btrfs_release_path(path);
2095                 if (ret)
2096                         break;
2097
2098         }
2099         if (ret > 0)
2100                 ret = 0;
2101 err:
2102         sk->nr_items = num_found;
2103         btrfs_free_path(path);
2104         return ret;
2105 }
2106
2107 static noinline int btrfs_ioctl_tree_search(struct file *file,
2108                                            void __user *argp)
2109 {
2110         struct btrfs_ioctl_search_args __user *uargs;
2111         struct btrfs_ioctl_search_key sk;
2112         struct inode *inode;
2113         int ret;
2114         size_t buf_size;
2115
2116         if (!capable(CAP_SYS_ADMIN))
2117                 return -EPERM;
2118
2119         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2120
2121         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2122                 return -EFAULT;
2123
2124         buf_size = sizeof(uargs->buf);
2125
2126         inode = file_inode(file);
2127         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2128
2129         /*
2130          * In the origin implementation an overflow is handled by returning a
2131          * search header with a len of zero, so reset ret.
2132          */
2133         if (ret == -EOVERFLOW)
2134                 ret = 0;
2135
2136         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2137                 ret = -EFAULT;
2138         return ret;
2139 }
2140
2141 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2142                                                void __user *argp)
2143 {
2144         struct btrfs_ioctl_search_args_v2 __user *uarg;
2145         struct btrfs_ioctl_search_args_v2 args;
2146         struct inode *inode;
2147         int ret;
2148         size_t buf_size;
2149         const size_t buf_limit = 16 * 1024 * 1024;
2150
2151         if (!capable(CAP_SYS_ADMIN))
2152                 return -EPERM;
2153
2154         /* copy search header and buffer size */
2155         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2156         if (copy_from_user(&args, uarg, sizeof(args)))
2157                 return -EFAULT;
2158
2159         buf_size = args.buf_size;
2160
2161         if (buf_size < sizeof(struct btrfs_ioctl_search_header))
2162                 return -EOVERFLOW;
2163
2164         /* limit result size to 16MB */
2165         if (buf_size > buf_limit)
2166                 buf_size = buf_limit;
2167
2168         inode = file_inode(file);
2169         ret = search_ioctl(inode, &args.key, &buf_size,
2170                            (char *)(&uarg->buf[0]));
2171         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2172                 ret = -EFAULT;
2173         else if (ret == -EOVERFLOW &&
2174                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2175                 ret = -EFAULT;
2176
2177         return ret;
2178 }
2179
2180 /*
2181  * Search INODE_REFs to identify path name of 'dirid' directory
2182  * in a 'tree_id' tree. and sets path name to 'name'.
2183  */
2184 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2185                                 u64 tree_id, u64 dirid, char *name)
2186 {
2187         struct btrfs_root *root;
2188         struct btrfs_key key;
2189         char *ptr;
2190         int ret = -1;
2191         int slot;
2192         int len;
2193         int total_len = 0;
2194         struct btrfs_inode_ref *iref;
2195         struct extent_buffer *l;
2196         struct btrfs_path *path;
2197
2198         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2199                 name[0]='\0';
2200                 return 0;
2201         }
2202
2203         path = btrfs_alloc_path();
2204         if (!path)
2205                 return -ENOMEM;
2206
2207         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2208
2209         key.objectid = tree_id;
2210         key.type = BTRFS_ROOT_ITEM_KEY;
2211         key.offset = (u64)-1;
2212         root = btrfs_read_fs_root_no_name(info, &key);
2213         if (IS_ERR(root)) {
2214                 printk(KERN_ERR "BTRFS: could not find root %llu\n", tree_id);
2215                 ret = -ENOENT;
2216                 goto out;
2217         }
2218
2219         key.objectid = dirid;
2220         key.type = BTRFS_INODE_REF_KEY;
2221         key.offset = (u64)-1;
2222
2223         while (1) {
2224                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2225                 if (ret < 0)
2226                         goto out;
2227                 else if (ret > 0) {
2228                         ret = btrfs_previous_item(root, path, dirid,
2229                                                   BTRFS_INODE_REF_KEY);
2230                         if (ret < 0)
2231                                 goto out;
2232                         else if (ret > 0) {
2233                                 ret = -ENOENT;
2234                                 goto out;
2235                         }
2236                 }
2237
2238                 l = path->nodes[0];
2239                 slot = path->slots[0];
2240                 btrfs_item_key_to_cpu(l, &key, slot);
2241
2242                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2243                 len = btrfs_inode_ref_name_len(l, iref);
2244                 ptr -= len + 1;
2245                 total_len += len + 1;
2246                 if (ptr < name) {
2247                         ret = -ENAMETOOLONG;
2248                         goto out;
2249                 }
2250
2251                 *(ptr + len) = '/';
2252                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2253
2254                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2255                         break;
2256
2257                 btrfs_release_path(path);
2258                 key.objectid = key.offset;
2259                 key.offset = (u64)-1;
2260                 dirid = key.objectid;
2261         }
2262         memmove(name, ptr, total_len);
2263         name[total_len] = '\0';
2264         ret = 0;
2265 out:
2266         btrfs_free_path(path);
2267         return ret;
2268 }
2269
2270 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2271                                            void __user *argp)
2272 {
2273          struct btrfs_ioctl_ino_lookup_args *args;
2274          struct inode *inode;
2275         int ret = 0;
2276
2277         args = memdup_user(argp, sizeof(*args));
2278         if (IS_ERR(args))
2279                 return PTR_ERR(args);
2280
2281         inode = file_inode(file);
2282
2283         /*
2284          * Unprivileged query to obtain the containing subvolume root id. The
2285          * path is reset so it's consistent with btrfs_search_path_in_tree.
2286          */
2287         if (args->treeid == 0)
2288                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2289
2290         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2291                 args->name[0] = 0;
2292                 goto out;
2293         }
2294
2295         if (!capable(CAP_SYS_ADMIN)) {
2296                 ret = -EPERM;
2297                 goto out;
2298         }
2299
2300         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2301                                         args->treeid, args->objectid,
2302                                         args->name);
2303
2304 out:
2305         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2306                 ret = -EFAULT;
2307
2308         kfree(args);
2309         return ret;
2310 }
2311
2312 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2313                                              void __user *arg)
2314 {
2315         struct dentry *parent = file->f_path.dentry;
2316         struct dentry *dentry;
2317         struct inode *dir = d_inode(parent);
2318         struct inode *inode;
2319         struct btrfs_root *root = BTRFS_I(dir)->root;
2320         struct btrfs_root *dest = NULL;
2321         struct btrfs_ioctl_vol_args *vol_args;
2322         struct btrfs_trans_handle *trans;
2323         struct btrfs_block_rsv block_rsv;
2324         u64 root_flags;
2325         u64 qgroup_reserved;
2326         int namelen;
2327         int ret;
2328         int err = 0;
2329
2330         vol_args = memdup_user(arg, sizeof(*vol_args));
2331         if (IS_ERR(vol_args))
2332                 return PTR_ERR(vol_args);
2333
2334         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2335         namelen = strlen(vol_args->name);
2336         if (strchr(vol_args->name, '/') ||
2337             strncmp(vol_args->name, "..", namelen) == 0) {
2338                 err = -EINVAL;
2339                 goto out;
2340         }
2341
2342         err = mnt_want_write_file(file);
2343         if (err)
2344                 goto out;
2345
2346
2347         err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
2348         if (err == -EINTR)
2349                 goto out_drop_write;
2350         dentry = lookup_one_len(vol_args->name, parent, namelen);
2351         if (IS_ERR(dentry)) {
2352                 err = PTR_ERR(dentry);
2353                 goto out_unlock_dir;
2354         }
2355
2356         if (d_really_is_negative(dentry)) {
2357                 err = -ENOENT;
2358                 goto out_dput;
2359         }
2360
2361         inode = d_inode(dentry);
2362         dest = BTRFS_I(inode)->root;
2363         if (!capable(CAP_SYS_ADMIN)) {
2364                 /*
2365                  * Regular user.  Only allow this with a special mount
2366                  * option, when the user has write+exec access to the
2367                  * subvol root, and when rmdir(2) would have been
2368                  * allowed.
2369                  *
2370                  * Note that this is _not_ check that the subvol is
2371                  * empty or doesn't contain data that we wouldn't
2372                  * otherwise be able to delete.
2373                  *
2374                  * Users who want to delete empty subvols should try
2375                  * rmdir(2).
2376                  */
2377                 err = -EPERM;
2378                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2379                         goto out_dput;
2380
2381                 /*
2382                  * Do not allow deletion if the parent dir is the same
2383                  * as the dir to be deleted.  That means the ioctl
2384                  * must be called on the dentry referencing the root
2385                  * of the subvol, not a random directory contained
2386                  * within it.
2387                  */
2388                 err = -EINVAL;
2389                 if (root == dest)
2390                         goto out_dput;
2391
2392                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2393                 if (err)
2394                         goto out_dput;
2395         }
2396
2397         /* check if subvolume may be deleted by a user */
2398         err = btrfs_may_delete(dir, dentry, 1);
2399         if (err)
2400                 goto out_dput;
2401
2402         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2403                 err = -EINVAL;
2404                 goto out_dput;
2405         }
2406
2407         mutex_lock(&inode->i_mutex);
2408
2409         /*
2410          * Don't allow to delete a subvolume with send in progress. This is
2411          * inside the i_mutex so the error handling that has to drop the bit
2412          * again is not run concurrently.
2413          */
2414         spin_lock(&dest->root_item_lock);
2415         root_flags = btrfs_root_flags(&dest->root_item);
2416         if (dest->send_in_progress == 0) {
2417                 btrfs_set_root_flags(&dest->root_item,
2418                                 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2419                 spin_unlock(&dest->root_item_lock);
2420         } else {
2421                 spin_unlock(&dest->root_item_lock);
2422                 btrfs_warn(root->fs_info,
2423                         "Attempt to delete subvolume %llu during send",
2424                         dest->root_key.objectid);
2425                 err = -EPERM;
2426                 goto out_unlock_inode;
2427         }
2428
2429         down_write(&root->fs_info->subvol_sem);
2430
2431         err = may_destroy_subvol(dest);
2432         if (err)
2433                 goto out_up_write;
2434
2435         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2436         /*
2437          * One for dir inode, two for dir entries, two for root
2438          * ref/backref.
2439          */
2440         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2441                                                5, &qgroup_reserved, true);
2442         if (err)
2443                 goto out_up_write;
2444
2445         trans = btrfs_start_transaction(root, 0);
2446         if (IS_ERR(trans)) {
2447                 err = PTR_ERR(trans);
2448                 goto out_release;
2449         }
2450         trans->block_rsv = &block_rsv;
2451         trans->bytes_reserved = block_rsv.size;
2452
2453         ret = btrfs_unlink_subvol(trans, root, dir,
2454                                 dest->root_key.objectid,
2455                                 dentry->d_name.name,
2456                                 dentry->d_name.len);
2457         if (ret) {
2458                 err = ret;
2459                 btrfs_abort_transaction(trans, root, ret);
2460                 goto out_end_trans;
2461         }
2462
2463         btrfs_record_root_in_trans(trans, dest);
2464
2465         memset(&dest->root_item.drop_progress, 0,
2466                 sizeof(dest->root_item.drop_progress));
2467         dest->root_item.drop_level = 0;
2468         btrfs_set_root_refs(&dest->root_item, 0);
2469
2470         if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2471                 ret = btrfs_insert_orphan_item(trans,
2472                                         root->fs_info->tree_root,
2473                                         dest->root_key.objectid);
2474                 if (ret) {
2475                         btrfs_abort_transaction(trans, root, ret);
2476                         err = ret;
2477                         goto out_end_trans;
2478                 }
2479         }
2480
2481         ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2482                                   dest->root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
2483                                   dest->root_key.objectid);
2484         if (ret && ret != -ENOENT) {
2485                 btrfs_abort_transaction(trans, root, ret);
2486                 err = ret;
2487                 goto out_end_trans;
2488         }
2489         if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2490                 ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2491                                           dest->root_item.received_uuid,
2492                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2493                                           dest->root_key.objectid);
2494                 if (ret && ret != -ENOENT) {
2495                         btrfs_abort_transaction(trans, root, ret);
2496                         err = ret;
2497                         goto out_end_trans;
2498                 }
2499         }
2500
2501 out_end_trans:
2502         trans->block_rsv = NULL;
2503         trans->bytes_reserved = 0;
2504         ret = btrfs_end_transaction(trans, root);
2505         if (ret && !err)
2506                 err = ret;
2507         inode->i_flags |= S_DEAD;
2508 out_release:
2509         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
2510 out_up_write:
2511         up_write(&root->fs_info->subvol_sem);
2512         if (err) {
2513                 spin_lock(&dest->root_item_lock);
2514                 root_flags = btrfs_root_flags(&dest->root_item);
2515                 btrfs_set_root_flags(&dest->root_item,
2516                                 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2517                 spin_unlock(&dest->root_item_lock);
2518         }
2519 out_unlock_inode:
2520         mutex_unlock(&inode->i_mutex);
2521         if (!err) {
2522                 d_invalidate(dentry);
2523                 btrfs_invalidate_inodes(dest);
2524                 d_delete(dentry);
2525                 ASSERT(dest->send_in_progress == 0);
2526
2527                 /* the last ref */
2528                 if (dest->ino_cache_inode) {
2529                         iput(dest->ino_cache_inode);
2530                         dest->ino_cache_inode = NULL;
2531                 }
2532         }
2533 out_dput:
2534         dput(dentry);
2535 out_unlock_dir:
2536         mutex_unlock(&dir->i_mutex);
2537 out_drop_write:
2538         mnt_drop_write_file(file);
2539 out:
2540         kfree(vol_args);
2541         return err;
2542 }
2543
2544 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2545 {
2546         struct inode *inode = file_inode(file);
2547         struct btrfs_root *root = BTRFS_I(inode)->root;
2548         struct btrfs_ioctl_defrag_range_args *range;
2549         int ret;
2550
2551         ret = mnt_want_write_file(file);
2552         if (ret)
2553                 return ret;
2554
2555         if (btrfs_root_readonly(root)) {
2556                 ret = -EROFS;
2557                 goto out;
2558         }
2559
2560         switch (inode->i_mode & S_IFMT) {
2561         case S_IFDIR:
2562                 if (!capable(CAP_SYS_ADMIN)) {
2563                         ret = -EPERM;
2564                         goto out;
2565                 }
2566                 ret = btrfs_defrag_root(root);
2567                 if (ret)
2568                         goto out;
2569                 ret = btrfs_defrag_root(root->fs_info->extent_root);
2570                 break;
2571         case S_IFREG:
2572                 if (!(file->f_mode & FMODE_WRITE)) {
2573                         ret = -EINVAL;
2574                         goto out;
2575                 }
2576
2577                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2578                 if (!range) {
2579                         ret = -ENOMEM;
2580                         goto out;
2581                 }
2582
2583                 if (argp) {
2584                         if (copy_from_user(range, argp,
2585                                            sizeof(*range))) {
2586                                 ret = -EFAULT;
2587                                 kfree(range);
2588                                 goto out;
2589                         }
2590                         /* compression requires us to start the IO */
2591                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2592                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2593                                 range->extent_thresh = (u32)-1;
2594                         }
2595                 } else {
2596                         /* the rest are all set to zero by kzalloc */
2597                         range->len = (u64)-1;
2598                 }
2599                 ret = btrfs_defrag_file(file_inode(file), file,
2600                                         range, 0, 0);
2601                 if (ret > 0)
2602                         ret = 0;
2603                 kfree(range);
2604                 break;
2605         default:
2606                 ret = -EINVAL;
2607         }
2608 out:
2609         mnt_drop_write_file(file);
2610         return ret;
2611 }
2612
2613 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2614 {
2615         struct btrfs_ioctl_vol_args *vol_args;
2616         int ret;
2617
2618         if (!capable(CAP_SYS_ADMIN))
2619                 return -EPERM;
2620
2621         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2622                         1)) {
2623                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2624         }
2625
2626         mutex_lock(&root->fs_info->volume_mutex);
2627         vol_args = memdup_user(arg, sizeof(*vol_args));
2628         if (IS_ERR(vol_args)) {
2629                 ret = PTR_ERR(vol_args);
2630                 goto out;
2631         }
2632
2633         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2634         ret = btrfs_init_new_device(root, vol_args->name);
2635
2636         if (!ret)
2637                 btrfs_info(root->fs_info, "disk added %s",vol_args->name);
2638
2639         kfree(vol_args);
2640 out:
2641         mutex_unlock(&root->fs_info->volume_mutex);
2642         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2643         return ret;
2644 }
2645
2646 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2647 {
2648         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
2649         struct btrfs_ioctl_vol_args *vol_args;
2650         int ret;
2651
2652         if (!capable(CAP_SYS_ADMIN))
2653                 return -EPERM;
2654
2655         ret = mnt_want_write_file(file);
2656         if (ret)
2657                 return ret;
2658
2659         vol_args = memdup_user(arg, sizeof(*vol_args));
2660         if (IS_ERR(vol_args)) {
2661                 ret = PTR_ERR(vol_args);
2662                 goto err_drop;
2663         }
2664
2665         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2666
2667         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2668                         1)) {
2669                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2670                 goto out;
2671         }
2672
2673         mutex_lock(&root->fs_info->volume_mutex);
2674         ret = btrfs_rm_device(root, vol_args->name);
2675         mutex_unlock(&root->fs_info->volume_mutex);
2676         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2677
2678         if (!ret)
2679                 btrfs_info(root->fs_info, "disk deleted %s",vol_args->name);
2680
2681 out:
2682         kfree(vol_args);
2683 err_drop:
2684         mnt_drop_write_file(file);
2685         return ret;
2686 }
2687
2688 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2689 {
2690         struct btrfs_ioctl_fs_info_args *fi_args;
2691         struct btrfs_device *device;
2692         struct btrfs_device *next;
2693         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2694         int ret = 0;
2695
2696         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2697         if (!fi_args)
2698                 return -ENOMEM;
2699
2700         mutex_lock(&fs_devices->device_list_mutex);
2701         fi_args->num_devices = fs_devices->num_devices;
2702         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2703
2704         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2705                 if (device->devid > fi_args->max_id)
2706                         fi_args->max_id = device->devid;
2707         }
2708         mutex_unlock(&fs_devices->device_list_mutex);
2709
2710         fi_args->nodesize = root->fs_info->super_copy->nodesize;
2711         fi_args->sectorsize = root->fs_info->super_copy->sectorsize;
2712         fi_args->clone_alignment = root->fs_info->super_copy->sectorsize;
2713
2714         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2715                 ret = -EFAULT;
2716
2717         kfree(fi_args);
2718         return ret;
2719 }
2720
2721 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2722 {
2723         struct btrfs_ioctl_dev_info_args *di_args;
2724         struct btrfs_device *dev;
2725         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2726         int ret = 0;
2727         char *s_uuid = NULL;
2728
2729         di_args = memdup_user(arg, sizeof(*di_args));
2730         if (IS_ERR(di_args))
2731                 return PTR_ERR(di_args);
2732
2733         if (!btrfs_is_empty_uuid(di_args->uuid))
2734                 s_uuid = di_args->uuid;
2735
2736         mutex_lock(&fs_devices->device_list_mutex);
2737         dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
2738
2739         if (!dev) {
2740                 ret = -ENODEV;
2741                 goto out;
2742         }
2743
2744         di_args->devid = dev->devid;
2745         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2746         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2747         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2748         if (dev->name) {
2749                 struct rcu_string *name;
2750
2751                 rcu_read_lock();
2752                 name = rcu_dereference(dev->name);
2753                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2754                 rcu_read_unlock();
2755                 di_args->path[sizeof(di_args->path) - 1] = 0;
2756         } else {
2757                 di_args->path[0] = '\0';
2758         }
2759
2760 out:
2761         mutex_unlock(&fs_devices->device_list_mutex);
2762         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2763                 ret = -EFAULT;
2764
2765         kfree(di_args);
2766         return ret;
2767 }
2768
2769 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2770 {
2771         struct page *page;
2772         struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2773
2774         page = grab_cache_page(inode->i_mapping, index);
2775         if (!page)
2776                 return NULL;
2777
2778         if (!PageUptodate(page)) {
2779                 if (extent_read_full_page_nolock(tree, page, btrfs_get_extent,
2780                                                  0))
2781                         return NULL;
2782                 lock_page(page);
2783                 if (!PageUptodate(page)) {
2784                         unlock_page(page);
2785                         page_cache_release(page);
2786                         return NULL;
2787                 }
2788         }
2789         unlock_page(page);
2790
2791         return page;
2792 }
2793
2794 static int gather_extent_pages(struct inode *inode, struct page **pages,
2795                                int num_pages, u64 off)
2796 {
2797         int i;
2798         pgoff_t index = off >> PAGE_CACHE_SHIFT;
2799
2800         for (i = 0; i < num_pages; i++) {
2801                 pages[i] = extent_same_get_page(inode, index + i);
2802                 if (!pages[i])
2803                         return -ENOMEM;
2804         }
2805         return 0;
2806 }
2807
2808 static inline void lock_extent_range(struct inode *inode, u64 off, u64 len)
2809 {
2810         /* do any pending delalloc/csum calc on src, one way or
2811            another, and lock file content */
2812         while (1) {
2813                 struct btrfs_ordered_extent *ordered;
2814                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2815                 ordered = btrfs_lookup_first_ordered_extent(inode,
2816                                                             off + len - 1);
2817                 if ((!ordered ||
2818                      ordered->file_offset + ordered->len <= off ||
2819                      ordered->file_offset >= off + len) &&
2820                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2821                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2822                         if (ordered)
2823                                 btrfs_put_ordered_extent(ordered);
2824                         break;
2825                 }
2826                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2827                 if (ordered)
2828                         btrfs_put_ordered_extent(ordered);
2829                 btrfs_wait_ordered_range(inode, off, len);
2830         }
2831 }
2832
2833 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2834 {
2835         mutex_unlock(&inode1->i_mutex);
2836         mutex_unlock(&inode2->i_mutex);
2837 }
2838
2839 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2840 {
2841         if (inode1 < inode2)
2842                 swap(inode1, inode2);
2843
2844         mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
2845         if (inode1 != inode2)
2846                 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
2847 }
2848
2849 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2850                                       struct inode *inode2, u64 loff2, u64 len)
2851 {
2852         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2853         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2854 }
2855
2856 static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2857                                      struct inode *inode2, u64 loff2, u64 len)
2858 {
2859         if (inode1 < inode2) {
2860                 swap(inode1, inode2);
2861                 swap(loff1, loff2);
2862         }
2863         lock_extent_range(inode1, loff1, len);
2864         if (inode1 != inode2)
2865                 lock_extent_range(inode2, loff2, len);
2866 }
2867
2868 struct cmp_pages {
2869         int             num_pages;
2870         struct page     **src_pages;
2871         struct page     **dst_pages;
2872 };
2873
2874 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
2875 {
2876         int i;
2877         struct page *pg;
2878
2879         for (i = 0; i < cmp->num_pages; i++) {
2880                 pg = cmp->src_pages[i];
2881                 if (pg)
2882                         page_cache_release(pg);
2883                 pg = cmp->dst_pages[i];
2884                 if (pg)
2885                         page_cache_release(pg);
2886         }
2887         kfree(cmp->src_pages);
2888         kfree(cmp->dst_pages);
2889 }
2890
2891 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
2892                                   struct inode *dst, u64 dst_loff,
2893                                   u64 len, struct cmp_pages *cmp)
2894 {
2895         int ret;
2896         int num_pages = PAGE_CACHE_ALIGN(len) >> PAGE_CACHE_SHIFT;
2897         struct page **src_pgarr, **dst_pgarr;
2898
2899         /*
2900          * We must gather up all the pages before we initiate our
2901          * extent locking. We use an array for the page pointers. Size
2902          * of the array is bounded by len, which is in turn bounded by
2903          * BTRFS_MAX_DEDUPE_LEN.
2904          */
2905         src_pgarr = kzalloc(num_pages * sizeof(struct page *), GFP_NOFS);
2906         dst_pgarr = kzalloc(num_pages * sizeof(struct page *), GFP_NOFS);
2907         if (!src_pgarr || !dst_pgarr) {
2908                 kfree(src_pgarr);
2909                 kfree(dst_pgarr);
2910                 return -ENOMEM;
2911         }
2912         cmp->num_pages = num_pages;
2913         cmp->src_pages = src_pgarr;
2914         cmp->dst_pages = dst_pgarr;
2915
2916         ret = gather_extent_pages(src, cmp->src_pages, cmp->num_pages, loff);
2917         if (ret)
2918                 goto out;
2919
2920         ret = gather_extent_pages(dst, cmp->dst_pages, cmp->num_pages, dst_loff);
2921
2922 out:
2923         if (ret)
2924                 btrfs_cmp_data_free(cmp);
2925         return 0;
2926 }
2927
2928 static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
2929                           u64 dst_loff, u64 len, struct cmp_pages *cmp)
2930 {
2931         int ret = 0;
2932         int i;
2933         struct page *src_page, *dst_page;
2934         unsigned int cmp_len = PAGE_CACHE_SIZE;
2935         void *addr, *dst_addr;
2936
2937         i = 0;
2938         while (len) {
2939                 if (len < PAGE_CACHE_SIZE)
2940                         cmp_len = len;
2941
2942                 BUG_ON(i >= cmp->num_pages);
2943
2944                 src_page = cmp->src_pages[i];
2945                 dst_page = cmp->dst_pages[i];
2946
2947                 addr = kmap_atomic(src_page);
2948                 dst_addr = kmap_atomic(dst_page);
2949
2950                 flush_dcache_page(src_page);
2951                 flush_dcache_page(dst_page);
2952
2953                 if (memcmp(addr, dst_addr, cmp_len))
2954                         ret = BTRFS_SAME_DATA_DIFFERS;
2955
2956                 kunmap_atomic(addr);
2957                 kunmap_atomic(dst_addr);
2958
2959                 if (ret)
2960                         break;
2961
2962                 len -= cmp_len;
2963                 i++;
2964         }
2965
2966         return ret;
2967 }
2968
2969 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
2970                                      u64 olen)
2971 {
2972         u64 len = *plen;
2973         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
2974
2975         if (off + olen > inode->i_size || off + olen < off)
2976                 return -EINVAL;
2977
2978         /* if we extend to eof, continue to block boundary */
2979         if (off + len == inode->i_size)
2980                 *plen = len = ALIGN(inode->i_size, bs) - off;
2981
2982         /* Check that we are block aligned - btrfs_clone() requires this */
2983         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
2984                 return -EINVAL;
2985
2986         return 0;
2987 }
2988
2989 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
2990                              struct inode *dst, u64 dst_loff)
2991 {
2992         int ret;
2993         u64 len = olen;
2994         struct cmp_pages cmp;
2995         int same_inode = 0;
2996         u64 same_lock_start = 0;
2997         u64 same_lock_len = 0;
2998
2999         if (src == dst)
3000                 same_inode = 1;
3001
3002         if (len == 0)
3003                 return 0;
3004
3005         if (same_inode) {
3006                 mutex_lock(&src->i_mutex);
3007
3008                 ret = extent_same_check_offsets(src, loff, &len, olen);
3009                 if (ret)
3010                         goto out_unlock;
3011
3012                 /*
3013                  * Single inode case wants the same checks, except we
3014                  * don't want our length pushed out past i_size as
3015                  * comparing that data range makes no sense.
3016                  *
3017                  * extent_same_check_offsets() will do this for an
3018                  * unaligned length at i_size, so catch it here and
3019                  * reject the request.
3020                  *
3021                  * This effectively means we require aligned extents
3022                  * for the single-inode case, whereas the other cases
3023                  * allow an unaligned length so long as it ends at
3024                  * i_size.
3025                  */
3026                 if (len != olen) {
3027                         ret = -EINVAL;
3028                         goto out_unlock;
3029                 }
3030
3031                 /* Check for overlapping ranges */
3032                 if (dst_loff + len > loff && dst_loff < loff + len) {
3033                         ret = -EINVAL;
3034                         goto out_unlock;
3035                 }
3036
3037                 same_lock_start = min_t(u64, loff, dst_loff);
3038                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3039         } else {
3040                 btrfs_double_inode_lock(src, dst);
3041
3042                 ret = extent_same_check_offsets(src, loff, &len, olen);
3043                 if (ret)
3044                         goto out_unlock;
3045
3046                 ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3047                 if (ret)
3048                         goto out_unlock;
3049         }
3050
3051         /* don't make the dst file partly checksummed */
3052         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3053             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3054                 ret = -EINVAL;
3055                 goto out_unlock;
3056         }
3057
3058         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3059         if (ret)
3060                 goto out_unlock;
3061
3062         if (same_inode)
3063                 lock_extent_range(src, same_lock_start, same_lock_len);
3064         else
3065                 btrfs_double_extent_lock(src, loff, dst, dst_loff, len);
3066
3067         /* pass original length for comparison so we stay within i_size */
3068         ret = btrfs_cmp_data(src, loff, dst, dst_loff, olen, &cmp);
3069         if (ret == 0)
3070                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3071
3072         if (same_inode)
3073                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3074                               same_lock_start + same_lock_len - 1);
3075         else
3076                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3077
3078         btrfs_cmp_data_free(&cmp);
3079 out_unlock:
3080         if (same_inode)
3081                 mutex_unlock(&src->i_mutex);
3082         else
3083                 btrfs_double_inode_unlock(src, dst);
3084
3085         return ret;
3086 }
3087
3088 #define BTRFS_MAX_DEDUPE_LEN    (16 * 1024 * 1024)
3089
3090 static long btrfs_ioctl_file_extent_same(struct file *file,
3091                         struct btrfs_ioctl_same_args __user *argp)
3092 {
3093         struct btrfs_ioctl_same_args *same;
3094         struct btrfs_ioctl_same_extent_info *info;
3095         struct inode *src = file_inode(file);
3096         u64 off;
3097         u64 len;
3098         int i;
3099         int ret;
3100         unsigned long size;
3101         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3102         bool is_admin = capable(CAP_SYS_ADMIN);
3103         u16 count;
3104
3105         if (!(file->f_mode & FMODE_READ))
3106                 return -EINVAL;
3107
3108         ret = mnt_want_write_file(file);
3109         if (ret)
3110                 return ret;
3111
3112         if (get_user(count, &argp->dest_count)) {
3113                 ret = -EFAULT;
3114                 goto out;
3115         }
3116
3117         size = offsetof(struct btrfs_ioctl_same_args __user, info[count]);
3118
3119         same = memdup_user(argp, size);
3120
3121         if (IS_ERR(same)) {
3122                 ret = PTR_ERR(same);
3123                 goto out;
3124         }
3125
3126         off = same->logical_offset;
3127         len = same->length;
3128
3129         /*
3130          * Limit the total length we will dedupe for each operation.
3131          * This is intended to bound the total time spent in this
3132          * ioctl to something sane.
3133          */
3134         if (len > BTRFS_MAX_DEDUPE_LEN)
3135                 len = BTRFS_MAX_DEDUPE_LEN;
3136
3137         if (WARN_ON_ONCE(bs < PAGE_CACHE_SIZE)) {
3138                 /*
3139                  * Btrfs does not support blocksize < page_size. As a
3140                  * result, btrfs_cmp_data() won't correctly handle
3141                  * this situation without an update.
3142                  */
3143                 ret = -EINVAL;
3144                 goto out;
3145         }
3146
3147         ret = -EISDIR;
3148         if (S_ISDIR(src->i_mode))
3149                 goto out;
3150
3151         ret = -EACCES;
3152         if (!S_ISREG(src->i_mode))
3153                 goto out;
3154
3155         /* pre-format output fields to sane values */
3156         for (i = 0; i < count; i++) {
3157                 same->info[i].bytes_deduped = 0ULL;
3158                 same->info[i].status = 0;
3159         }
3160
3161         for (i = 0, info = same->info; i < count; i++, info++) {
3162                 struct inode *dst;
3163                 struct fd dst_file = fdget(info->fd);
3164                 if (!dst_file.file) {
3165                         info->status = -EBADF;
3166                         continue;
3167                 }
3168                 dst = file_inode(dst_file.file);
3169
3170                 if (!(is_admin || (dst_file.file->f_mode & FMODE_WRITE))) {
3171                         info->status = -EINVAL;
3172                 } else if (file->f_path.mnt != dst_file.file->f_path.mnt) {
3173                         info->status = -EXDEV;
3174                 } else if (S_ISDIR(dst->i_mode)) {
3175                         info->status = -EISDIR;
3176                 } else if (!S_ISREG(dst->i_mode)) {
3177                         info->status = -EACCES;
3178                 } else {
3179                         info->status = btrfs_extent_same(src, off, len, dst,
3180                                                         info->logical_offset);
3181                         if (info->status == 0)
3182                                 info->bytes_deduped += len;
3183                 }
3184                 fdput(dst_file);
3185         }
3186
3187         ret = copy_to_user(argp, same, size);
3188         if (ret)
3189                 ret = -EFAULT;
3190
3191 out:
3192         mnt_drop_write_file(file);
3193         return ret;
3194 }
3195
3196 /* Helper to check and see if this root currently has a ref on the given disk
3197  * bytenr.  If it does then we need to update the quota for this root.  This
3198  * doesn't do anything if quotas aren't enabled.
3199  */
3200 static int check_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3201                      u64 disko)
3202 {
3203         struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
3204         struct ulist *roots;
3205         struct ulist_iterator uiter;
3206         struct ulist_node *root_node = NULL;
3207         int ret;
3208
3209         if (!root->fs_info->quota_enabled)
3210                 return 1;
3211
3212         btrfs_get_tree_mod_seq(root->fs_info, &tree_mod_seq_elem);
3213         ret = btrfs_find_all_roots(trans, root->fs_info, disko,
3214                                    tree_mod_seq_elem.seq, &roots);
3215         if (ret < 0)
3216                 goto out;
3217         ret = 0;
3218         ULIST_ITER_INIT(&uiter);
3219         while ((root_node = ulist_next(roots, &uiter))) {
3220                 if (root_node->val == root->objectid) {
3221                         ret = 1;
3222                         break;
3223                 }
3224         }
3225         ulist_free(roots);
3226 out:
3227         btrfs_put_tree_mod_seq(root->fs_info, &tree_mod_seq_elem);
3228         return ret;
3229 }
3230
3231 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3232                                      struct inode *inode,
3233                                      u64 endoff,
3234                                      const u64 destoff,
3235                                      const u64 olen,
3236                                      int no_time_update)
3237 {
3238         struct btrfs_root *root = BTRFS_I(inode)->root;
3239         int ret;
3240
3241         inode_inc_iversion(inode);
3242         if (!no_time_update)
3243                 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3244         /*
3245          * We round up to the block size at eof when determining which
3246          * extents to clone above, but shouldn't round up the file size.
3247          */
3248         if (endoff > destoff + olen)
3249                 endoff = destoff + olen;
3250         if (endoff > inode->i_size)
3251                 btrfs_i_size_write(inode, endoff);
3252
3253         ret = btrfs_update_inode(trans, root, inode);
3254         if (ret) {
3255                 btrfs_abort_transaction(trans, root, ret);
3256                 btrfs_end_transaction(trans, root);
3257                 goto out;
3258         }
3259         ret = btrfs_end_transaction(trans, root);
3260 out:
3261         return ret;
3262 }
3263
3264 static void clone_update_extent_map(struct inode *inode,
3265                                     const struct btrfs_trans_handle *trans,
3266                                     const struct btrfs_path *path,
3267                                     const u64 hole_offset,
3268                                     const u64 hole_len)
3269 {
3270         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3271         struct extent_map *em;
3272         int ret;
3273
3274         em = alloc_extent_map();
3275         if (!em) {
3276                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3277                         &BTRFS_I(inode)->runtime_flags);
3278                 return;
3279         }
3280
3281         if (path) {
3282                 struct btrfs_file_extent_item *fi;
3283
3284                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3285                                     struct btrfs_file_extent_item);
3286                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3287                 em->generation = -1;
3288                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3289                     BTRFS_FILE_EXTENT_INLINE)
3290                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3291                                 &BTRFS_I(inode)->runtime_flags);
3292         } else {
3293                 em->start = hole_offset;
3294                 em->len = hole_len;
3295                 em->ram_bytes = em->len;
3296                 em->orig_start = hole_offset;
3297                 em->block_start = EXTENT_MAP_HOLE;
3298                 em->block_len = 0;
3299                 em->orig_block_len = 0;
3300                 em->compress_type = BTRFS_COMPRESS_NONE;
3301                 em->generation = trans->transid;
3302         }
3303
3304         while (1) {
3305                 write_lock(&em_tree->lock);
3306                 ret = add_extent_mapping(em_tree, em, 1);
3307                 write_unlock(&em_tree->lock);
3308                 if (ret != -EEXIST) {
3309                         free_extent_map(em);
3310                         break;
3311                 }
3312                 btrfs_drop_extent_cache(inode, em->start,
3313                                         em->start + em->len - 1, 0);
3314         }
3315
3316         if (ret)
3317                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3318                         &BTRFS_I(inode)->runtime_flags);
3319 }
3320
3321 /**
3322  * btrfs_clone() - clone a range from inode file to another
3323  *
3324  * @src: Inode to clone from
3325  * @inode: Inode to clone to
3326  * @off: Offset within source to start clone from
3327  * @olen: Original length, passed by user, of range to clone
3328  * @olen_aligned: Block-aligned value of olen
3329  * @destoff: Offset within @inode to start clone
3330  * @no_time_update: Whether to update mtime/ctime on the target inode
3331  */
3332 static int btrfs_clone(struct inode *src, struct inode *inode,
3333                        const u64 off, const u64 olen, const u64 olen_aligned,
3334                        const u64 destoff, int no_time_update)
3335 {
3336         struct btrfs_root *root = BTRFS_I(inode)->root;
3337         struct btrfs_path *path = NULL;
3338         struct extent_buffer *leaf;
3339         struct btrfs_trans_handle *trans;
3340         char *buf = NULL;
3341         struct btrfs_key key;
3342         u32 nritems;
3343         int slot;
3344         int ret;
3345         int no_quota;
3346         const u64 len = olen_aligned;
3347         u64 last_disko = 0;
3348         u64 last_dest_end = destoff;
3349
3350         ret = -ENOMEM;
3351         buf = vmalloc(root->nodesize);
3352         if (!buf)
3353                 return ret;
3354
3355         path = btrfs_alloc_path();
3356         if (!path) {
3357                 vfree(buf);
3358                 return ret;
3359         }
3360
3361         path->reada = 2;
3362         /* clone data */
3363         key.objectid = btrfs_ino(src);
3364         key.type = BTRFS_EXTENT_DATA_KEY;
3365         key.offset = off;
3366
3367         while (1) {
3368                 u64 next_key_min_offset = key.offset + 1;
3369
3370                 /*
3371                  * note the key will change type as we walk through the
3372                  * tree.
3373                  */
3374                 path->leave_spinning = 1;
3375                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3376                                 0, 0);
3377                 if (ret < 0)
3378                         goto out;
3379                 /*
3380                  * First search, if no extent item that starts at offset off was
3381                  * found but the previous item is an extent item, it's possible
3382                  * it might overlap our target range, therefore process it.
3383                  */
3384                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3385                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3386                                               path->slots[0] - 1);
3387                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3388                                 path->slots[0]--;
3389                 }
3390
3391                 nritems = btrfs_header_nritems(path->nodes[0]);
3392 process_slot:
3393                 no_quota = 1;
3394                 if (path->slots[0] >= nritems) {
3395                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3396                         if (ret < 0)
3397                                 goto out;
3398                         if (ret > 0)
3399                                 break;
3400                         nritems = btrfs_header_nritems(path->nodes[0]);
3401                 }
3402                 leaf = path->nodes[0];
3403                 slot = path->slots[0];
3404
3405                 btrfs_item_key_to_cpu(leaf, &key, slot);
3406                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3407                     key.objectid != btrfs_ino(src))
3408                         break;
3409
3410                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3411                         struct btrfs_file_extent_item *extent;
3412                         int type;
3413                         u32 size;
3414                         struct btrfs_key new_key;
3415                         u64 disko = 0, diskl = 0;
3416                         u64 datao = 0, datal = 0;
3417                         u8 comp;
3418                         u64 drop_start;
3419
3420                         extent = btrfs_item_ptr(leaf, slot,
3421                                                 struct btrfs_file_extent_item);
3422                         comp = btrfs_file_extent_compression(leaf, extent);
3423                         type = btrfs_file_extent_type(leaf, extent);
3424                         if (type == BTRFS_FILE_EXTENT_REG ||
3425                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3426                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3427                                                                       extent);
3428                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3429                                                                  extent);
3430                                 datao = btrfs_file_extent_offset(leaf, extent);
3431                                 datal = btrfs_file_extent_num_bytes(leaf,
3432                                                                     extent);
3433                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3434                                 /* take upper bound, may be compressed */
3435                                 datal = btrfs_file_extent_ram_bytes(leaf,
3436                                                                     extent);
3437                         }
3438
3439                         /*
3440                          * The first search might have left us at an extent
3441                          * item that ends before our target range's start, can
3442                          * happen if we have holes and NO_HOLES feature enabled.
3443                          */
3444                         if (key.offset + datal <= off) {
3445                                 path->slots[0]++;
3446                                 goto process_slot;
3447                         } else if (key.offset >= off + len) {
3448                                 break;
3449                         }
3450                         next_key_min_offset = key.offset + datal;
3451                         size = btrfs_item_size_nr(leaf, slot);
3452                         read_extent_buffer(leaf, buf,
3453                                            btrfs_item_ptr_offset(leaf, slot),
3454                                            size);
3455
3456                         btrfs_release_path(path);
3457                         path->leave_spinning = 0;
3458
3459                         memcpy(&new_key, &key, sizeof(new_key));
3460                         new_key.objectid = btrfs_ino(inode);
3461                         if (off <= key.offset)
3462                                 new_key.offset = key.offset + destoff - off;
3463                         else
3464                                 new_key.offset = destoff;
3465
3466                         /*
3467                          * Deal with a hole that doesn't have an extent item
3468                          * that represents it (NO_HOLES feature enabled).
3469                          * This hole is either in the middle of the cloning
3470                          * range or at the beginning (fully overlaps it or
3471                          * partially overlaps it).
3472                          */
3473                         if (new_key.offset != last_dest_end)
3474                                 drop_start = last_dest_end;
3475                         else
3476                                 drop_start = new_key.offset;
3477
3478                         /*
3479                          * 1 - adjusting old extent (we may have to split it)
3480                          * 1 - add new extent
3481                          * 1 - inode update
3482                          */
3483                         trans = btrfs_start_transaction(root, 3);
3484                         if (IS_ERR(trans)) {
3485                                 ret = PTR_ERR(trans);
3486                                 goto out;
3487                         }
3488
3489                         if (type == BTRFS_FILE_EXTENT_REG ||
3490                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3491                                 /*
3492                                  *    a  | --- range to clone ---|  b
3493                                  * | ------------- extent ------------- |
3494                                  */
3495
3496                                 /* subtract range b */
3497                                 if (key.offset + datal > off + len)
3498                                         datal = off + len - key.offset;
3499
3500                                 /* subtract range a */
3501                                 if (off > key.offset) {
3502                                         datao += off - key.offset;
3503                                         datal -= off - key.offset;
3504                                 }
3505
3506                                 ret = btrfs_drop_extents(trans, root, inode,
3507                                                          drop_start,
3508                                                          new_key.offset + datal,
3509                                                          1);
3510                                 if (ret) {
3511                                         if (ret != -EOPNOTSUPP)
3512                                                 btrfs_abort_transaction(trans,
3513                                                                 root, ret);
3514                                         btrfs_end_transaction(trans, root);
3515                                         goto out;
3516                                 }
3517
3518                                 ret = btrfs_insert_empty_item(trans, root, path,
3519                                                               &new_key, size);
3520                                 if (ret) {
3521                                         btrfs_abort_transaction(trans, root,
3522                                                                 ret);
3523                                         btrfs_end_transaction(trans, root);
3524                                         goto out;
3525                                 }
3526
3527                                 leaf = path->nodes[0];
3528                                 slot = path->slots[0];
3529                                 write_extent_buffer(leaf, buf,
3530                                             btrfs_item_ptr_offset(leaf, slot),
3531                                             size);
3532
3533                                 extent = btrfs_item_ptr(leaf, slot,
3534                                                 struct btrfs_file_extent_item);
3535
3536                                 /* disko == 0 means it's a hole */
3537                                 if (!disko)
3538                                         datao = 0;
3539
3540                                 btrfs_set_file_extent_offset(leaf, extent,
3541                                                              datao);
3542                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3543                                                                 datal);
3544
3545                                 /*
3546                                  * We need to look up the roots that point at
3547                                  * this bytenr and see if the new root does.  If
3548                                  * it does not we need to make sure we update
3549                                  * quotas appropriately.
3550                                  */
3551                                 if (disko && root != BTRFS_I(src)->root &&
3552                                     disko != last_disko) {
3553                                         no_quota = check_ref(trans, root,
3554                                                              disko);
3555                                         if (no_quota < 0) {
3556                                                 btrfs_abort_transaction(trans,
3557                                                                         root,
3558                                                                         ret);
3559                                                 btrfs_end_transaction(trans,
3560                                                                       root);
3561                                                 ret = no_quota;
3562                                                 goto out;
3563                                         }
3564                                 }
3565
3566                                 if (disko) {
3567                                         inode_add_bytes(inode, datal);
3568                                         ret = btrfs_inc_extent_ref(trans, root,
3569                                                         disko, diskl, 0,
3570                                                         root->root_key.objectid,
3571                                                         btrfs_ino(inode),
3572                                                         new_key.offset - datao,
3573                                                         no_quota);
3574                                         if (ret) {
3575                                                 btrfs_abort_transaction(trans,
3576                                                                         root,
3577                                                                         ret);
3578                                                 btrfs_end_transaction(trans,
3579                                                                       root);
3580                                                 goto out;
3581
3582                                         }
3583                                 }
3584                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3585                                 u64 skip = 0;
3586                                 u64 trim = 0;
3587                                 u64 aligned_end = 0;
3588
3589                                 if (off > key.offset) {
3590                                         skip = off - key.offset;
3591                                         new_key.offset += skip;
3592                                 }
3593
3594                                 if (key.offset + datal > off + len)
3595                                         trim = key.offset + datal - (off + len);
3596
3597                                 if (comp && (skip || trim)) {
3598                                         ret = -EINVAL;
3599                                         btrfs_end_transaction(trans, root);
3600                                         goto out;
3601                                 }
3602                                 size -= skip + trim;
3603                                 datal -= skip + trim;
3604
3605                                 aligned_end = ALIGN(new_key.offset + datal,
3606                                                     root->sectorsize);
3607                                 ret = btrfs_drop_extents(trans, root, inode,
3608                                                          drop_start,
3609                                                          aligned_end,
3610                                                          1);
3611                                 if (ret) {
3612                                         if (ret != -EOPNOTSUPP)
3613                                                 btrfs_abort_transaction(trans,
3614                                                         root, ret);
3615                                         btrfs_end_transaction(trans, root);
3616                                         goto out;
3617                                 }
3618
3619                                 ret = btrfs_insert_empty_item(trans, root, path,
3620                                                               &new_key, size);
3621                                 if (ret) {
3622                                         btrfs_abort_transaction(trans, root,
3623                                                                 ret);
3624                                         btrfs_end_transaction(trans, root);
3625                                         goto out;
3626                                 }
3627
3628                                 if (skip) {
3629                                         u32 start =
3630                                           btrfs_file_extent_calc_inline_size(0);
3631                                         memmove(buf+start, buf+start+skip,
3632                                                 datal);
3633                                 }
3634
3635                                 leaf = path->nodes[0];
3636                                 slot = path->slots[0];
3637                                 write_extent_buffer(leaf, buf,
3638                                             btrfs_item_ptr_offset(leaf, slot),
3639                                             size);
3640                                 inode_add_bytes(inode, datal);
3641                         }
3642
3643                         /* If we have an implicit hole (NO_HOLES feature). */
3644                         if (drop_start < new_key.offset)
3645                                 clone_update_extent_map(inode, trans,
3646                                                 NULL, drop_start,
3647                                                 new_key.offset - drop_start);
3648
3649                         clone_update_extent_map(inode, trans, path, 0, 0);
3650
3651                         btrfs_mark_buffer_dirty(leaf);
3652                         btrfs_release_path(path);
3653
3654                         last_dest_end = ALIGN(new_key.offset + datal,
3655                                               root->sectorsize);
3656                         ret = clone_finish_inode_update(trans, inode,
3657                                                         last_dest_end,
3658                                                         destoff, olen,
3659                                                         no_time_update);
3660                         if (ret)
3661                                 goto out;
3662                         if (new_key.offset + datal >= destoff + len)
3663                                 break;
3664                 }
3665                 btrfs_release_path(path);
3666                 key.offset = next_key_min_offset;
3667         }
3668         ret = 0;
3669
3670         if (last_dest_end < destoff + len) {
3671                 /*
3672                  * We have an implicit hole (NO_HOLES feature is enabled) that
3673                  * fully or partially overlaps our cloning range at its end.
3674                  */
3675                 btrfs_release_path(path);
3676
3677                 /*
3678                  * 1 - remove extent(s)
3679                  * 1 - inode update
3680                  */
3681                 trans = btrfs_start_transaction(root, 2);
3682                 if (IS_ERR(trans)) {
3683                         ret = PTR_ERR(trans);
3684                         goto out;
3685                 }
3686                 ret = btrfs_drop_extents(trans, root, inode,
3687                                          last_dest_end, destoff + len, 1);
3688                 if (ret) {
3689                         if (ret != -EOPNOTSUPP)
3690                                 btrfs_abort_transaction(trans, root, ret);
3691                         btrfs_end_transaction(trans, root);
3692                         goto out;
3693                 }
3694                 clone_update_extent_map(inode, trans, NULL, last_dest_end,
3695                                         destoff + len - last_dest_end);
3696                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3697                                                 destoff, olen, no_time_update);
3698         }
3699
3700 out:
3701         btrfs_free_path(path);
3702         vfree(buf);
3703         return ret;
3704 }
3705
3706 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
3707                                        u64 off, u64 olen, u64 destoff)
3708 {
3709         struct inode *inode = file_inode(file);
3710         struct btrfs_root *root = BTRFS_I(inode)->root;
3711         struct fd src_file;
3712         struct inode *src;
3713         int ret;
3714         u64 len = olen;
3715         u64 bs = root->fs_info->sb->s_blocksize;
3716         int same_inode = 0;
3717
3718         /*
3719          * TODO:
3720          * - split compressed inline extents.  annoying: we need to
3721          *   decompress into destination's address_space (the file offset
3722          *   may change, so source mapping won't do), then recompress (or
3723          *   otherwise reinsert) a subrange.
3724          *
3725          * - split destination inode's inline extents.  The inline extents can
3726          *   be either compressed or non-compressed.
3727          */
3728
3729         /* the destination must be opened for writing */
3730         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
3731                 return -EINVAL;
3732
3733         if (btrfs_root_readonly(root))
3734                 return -EROFS;
3735
3736         ret = mnt_want_write_file(file);
3737         if (ret)
3738                 return ret;
3739
3740         src_file = fdget(srcfd);
3741         if (!src_file.file) {
3742                 ret = -EBADF;
3743                 goto out_drop_write;
3744         }
3745
3746         ret = -EXDEV;
3747         if (src_file.file->f_path.mnt != file->f_path.mnt)
3748                 goto out_fput;
3749
3750         src = file_inode(src_file.file);
3751
3752         ret = -EINVAL;
3753         if (src == inode)
3754                 same_inode = 1;
3755
3756         /* the src must be open for reading */
3757         if (!(src_file.file->f_mode & FMODE_READ))
3758                 goto out_fput;
3759
3760         /* don't make the dst file partly checksummed */
3761         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3762             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3763                 goto out_fput;
3764
3765         ret = -EISDIR;
3766         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3767                 goto out_fput;
3768
3769         ret = -EXDEV;
3770         if (src->i_sb != inode->i_sb)
3771                 goto out_fput;
3772
3773         if (!same_inode) {
3774                 if (inode < src) {
3775                         mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
3776                         mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
3777                 } else {
3778                         mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
3779                         mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
3780                 }
3781         } else {
3782                 mutex_lock(&src->i_mutex);
3783         }
3784
3785         /* determine range to clone */
3786         ret = -EINVAL;
3787         if (off + len > src->i_size || off + len < off)
3788                 goto out_unlock;
3789         if (len == 0)
3790                 olen = len = src->i_size - off;
3791         /* if we extend to eof, continue to block boundary */
3792         if (off + len == src->i_size)
3793                 len = ALIGN(src->i_size, bs) - off;
3794
3795         if (len == 0) {
3796                 ret = 0;
3797                 goto out_unlock;
3798         }
3799
3800         /* verify the end result is block aligned */
3801         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3802             !IS_ALIGNED(destoff, bs))
3803                 goto out_unlock;
3804
3805         /* verify if ranges are overlapped within the same file */
3806         if (same_inode) {
3807                 if (destoff + len > off && destoff < off + len)
3808                         goto out_unlock;
3809         }
3810
3811         if (destoff > inode->i_size) {
3812                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3813                 if (ret)
3814                         goto out_unlock;
3815         }
3816
3817         /*
3818          * Lock the target range too. Right after we replace the file extent
3819          * items in the fs tree (which now point to the cloned data), we might
3820          * have a worker replace them with extent items relative to a write
3821          * operation that was issued before this clone operation (i.e. confront
3822          * with inode.c:btrfs_finish_ordered_io).
3823          */
3824         if (same_inode) {
3825                 u64 lock_start = min_t(u64, off, destoff);
3826                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3827
3828                 lock_extent_range(src, lock_start, lock_len);
3829         } else {
3830                 lock_extent_range(src, off, len);
3831                 lock_extent_range(inode, destoff, len);
3832         }
3833
3834         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3835
3836         if (same_inode) {
3837                 u64 lock_start = min_t(u64, off, destoff);
3838                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3839
3840                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3841         } else {
3842                 unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
3843                 unlock_extent(&BTRFS_I(inode)->io_tree, destoff,
3844                               destoff + len - 1);
3845         }
3846         /*
3847          * Truncate page cache pages so that future reads will see the cloned
3848          * data immediately and not the previous data.
3849          */
3850         truncate_inode_pages_range(&inode->i_data, destoff,
3851                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
3852 out_unlock:
3853         if (!same_inode) {
3854                 if (inode < src) {
3855                         mutex_unlock(&src->i_mutex);
3856                         mutex_unlock(&inode->i_mutex);
3857                 } else {
3858                         mutex_unlock(&inode->i_mutex);
3859                         mutex_unlock(&src->i_mutex);
3860                 }
3861         } else {
3862                 mutex_unlock(&src->i_mutex);
3863         }
3864 out_fput:
3865         fdput(src_file);
3866 out_drop_write:
3867         mnt_drop_write_file(file);
3868         return ret;
3869 }
3870
3871 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
3872 {
3873         struct btrfs_ioctl_clone_range_args args;
3874
3875         if (copy_from_user(&args, argp, sizeof(args)))
3876                 return -EFAULT;
3877         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
3878                                  args.src_length, args.dest_offset);
3879 }
3880
3881 /*
3882  * there are many ways the trans_start and trans_end ioctls can lead
3883  * to deadlocks.  They should only be used by applications that
3884  * basically own the machine, and have a very in depth understanding
3885  * of all the possible deadlocks and enospc problems.
3886  */
3887 static long btrfs_ioctl_trans_start(struct file *file)
3888 {
3889         struct inode *inode = file_inode(file);
3890         struct btrfs_root *root = BTRFS_I(inode)->root;
3891         struct btrfs_trans_handle *trans;
3892         int ret;
3893
3894         ret = -EPERM;
3895         if (!capable(CAP_SYS_ADMIN))
3896                 goto out;
3897
3898         ret = -EINPROGRESS;
3899         if (file->private_data)
3900                 goto out;
3901
3902         ret = -EROFS;
3903         if (btrfs_root_readonly(root))
3904                 goto out;
3905
3906         ret = mnt_want_write_file(file);
3907         if (ret)
3908                 goto out;
3909
3910         atomic_inc(&root->fs_info->open_ioctl_trans);
3911
3912         ret = -ENOMEM;
3913         trans = btrfs_start_ioctl_transaction(root);
3914         if (IS_ERR(trans))
3915                 goto out_drop;
3916
3917         file->private_data = trans;
3918         return 0;
3919
3920 out_drop:
3921         atomic_dec(&root->fs_info->open_ioctl_trans);
3922         mnt_drop_write_file(file);
3923 out:
3924         return ret;
3925 }
3926
3927 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3928 {
3929         struct inode *inode = file_inode(file);
3930         struct btrfs_root *root = BTRFS_I(inode)->root;
3931         struct btrfs_root *new_root;
3932         struct btrfs_dir_item *di;
3933         struct btrfs_trans_handle *trans;
3934         struct btrfs_path *path;
3935         struct btrfs_key location;
3936         struct btrfs_disk_key disk_key;
3937         u64 objectid = 0;
3938         u64 dir_id;
3939         int ret;
3940
3941         if (!capable(CAP_SYS_ADMIN))
3942                 return -EPERM;
3943
3944         ret = mnt_want_write_file(file);
3945         if (ret)
3946                 return ret;
3947
3948         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3949                 ret = -EFAULT;
3950                 goto out;
3951         }
3952
3953         if (!objectid)
3954                 objectid = BTRFS_FS_TREE_OBJECTID;
3955
3956         location.objectid = objectid;
3957         location.type = BTRFS_ROOT_ITEM_KEY;
3958         location.offset = (u64)-1;
3959
3960         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
3961         if (IS_ERR(new_root)) {
3962                 ret = PTR_ERR(new_root);
3963                 goto out;
3964         }
3965
3966         path = btrfs_alloc_path();
3967         if (!path) {
3968                 ret = -ENOMEM;
3969                 goto out;
3970         }
3971         path->leave_spinning = 1;
3972
3973         trans = btrfs_start_transaction(root, 1);
3974         if (IS_ERR(trans)) {
3975                 btrfs_free_path(path);
3976                 ret = PTR_ERR(trans);
3977                 goto out;
3978         }
3979
3980         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
3981         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
3982                                    dir_id, "default", 7, 1);
3983         if (IS_ERR_OR_NULL(di)) {
3984                 btrfs_free_path(path);
3985                 btrfs_end_transaction(trans, root);
3986                 btrfs_err(new_root->fs_info, "Umm, you don't have the default dir"
3987                            "item, this isn't going to work");
3988                 ret = -ENOENT;
3989                 goto out;
3990         }
3991
3992         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3993         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3994         btrfs_mark_buffer_dirty(path->nodes[0]);
3995         btrfs_free_path(path);
3996
3997         btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
3998         btrfs_end_transaction(trans, root);
3999 out:
4000         mnt_drop_write_file(file);
4001         return ret;
4002 }
4003
4004 void btrfs_get_block_group_info(struct list_head *groups_list,
4005                                 struct btrfs_ioctl_space_info *space)
4006 {
4007         struct btrfs_block_group_cache *block_group;
4008
4009         space->total_bytes = 0;
4010         space->used_bytes = 0;
4011         space->flags = 0;
4012         list_for_each_entry(block_group, groups_list, list) {
4013                 space->flags = block_group->flags;
4014                 space->total_bytes += block_group->key.offset;
4015                 space->used_bytes +=
4016                         btrfs_block_group_used(&block_group->item);
4017         }
4018 }
4019
4020 static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
4021 {
4022         struct btrfs_ioctl_space_args space_args;
4023         struct btrfs_ioctl_space_info space;
4024         struct btrfs_ioctl_space_info *dest;
4025         struct btrfs_ioctl_space_info *dest_orig;
4026         struct btrfs_ioctl_space_info __user *user_dest;
4027         struct btrfs_space_info *info;
4028         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
4029                        BTRFS_BLOCK_GROUP_SYSTEM,
4030                        BTRFS_BLOCK_GROUP_METADATA,
4031                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
4032         int num_types = 4;
4033         int alloc_size;
4034         int ret = 0;
4035         u64 slot_count = 0;
4036         int i, c;
4037
4038         if (copy_from_user(&space_args,
4039                            (struct btrfs_ioctl_space_args __user *)arg,
4040                            sizeof(space_args)))
4041                 return -EFAULT;
4042
4043         for (i = 0; i < num_types; i++) {
4044                 struct btrfs_space_info *tmp;
4045
4046                 info = NULL;
4047                 rcu_read_lock();
4048                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
4049                                         list) {
4050                         if (tmp->flags == types[i]) {
4051                                 info = tmp;
4052                                 break;
4053                         }
4054                 }
4055                 rcu_read_unlock();
4056
4057                 if (!info)
4058                         continue;
4059
4060                 down_read(&info->groups_sem);
4061                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4062                         if (!list_empty(&info->block_groups[c]))
4063                                 slot_count++;
4064                 }
4065                 up_read(&info->groups_sem);
4066         }
4067
4068         /*
4069          * Global block reserve, exported as a space_info
4070          */
4071         slot_count++;
4072
4073         /* space_slots == 0 means they are asking for a count */
4074         if (space_args.space_slots == 0) {
4075                 space_args.total_spaces = slot_count;
4076                 goto out;
4077         }
4078
4079         slot_count = min_t(u64, space_args.space_slots, slot_count);
4080
4081         alloc_size = sizeof(*dest) * slot_count;
4082
4083         /* we generally have at most 6 or so space infos, one for each raid
4084          * level.  So, a whole page should be more than enough for everyone
4085          */
4086         if (alloc_size > PAGE_CACHE_SIZE)
4087                 return -ENOMEM;
4088
4089         space_args.total_spaces = 0;
4090         dest = kmalloc(alloc_size, GFP_NOFS);
4091         if (!dest)
4092                 return -ENOMEM;
4093         dest_orig = dest;
4094
4095         /* now we have a buffer to copy into */
4096         for (i = 0; i < num_types; i++) {
4097                 struct btrfs_space_info *tmp;
4098
4099                 if (!slot_count)
4100                         break;
4101
4102                 info = NULL;
4103                 rcu_read_lock();
4104                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
4105                                         list) {
4106                         if (tmp->flags == types[i]) {
4107                                 info = tmp;
4108                                 break;
4109                         }
4110                 }
4111                 rcu_read_unlock();
4112
4113                 if (!info)
4114                         continue;
4115                 down_read(&info->groups_sem);
4116                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4117                         if (!list_empty(&info->block_groups[c])) {
4118                                 btrfs_get_block_group_info(
4119                                         &info->block_groups[c], &space);
4120                                 memcpy(dest, &space, sizeof(space));
4121                                 dest++;
4122                                 space_args.total_spaces++;
4123                                 slot_count--;
4124                         }
4125                         if (!slot_count)
4126                                 break;
4127                 }
4128                 up_read(&info->groups_sem);
4129         }
4130
4131         /*
4132          * Add global block reserve
4133          */
4134         if (slot_count) {
4135                 struct btrfs_block_rsv *block_rsv = &root->fs_info->global_block_rsv;
4136
4137                 spin_lock(&block_rsv->lock);
4138                 space.total_bytes = block_rsv->size;
4139                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4140                 spin_unlock(&block_rsv->lock);
4141                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4142                 memcpy(dest, &space, sizeof(space));
4143                 space_args.total_spaces++;
4144         }
4145
4146         user_dest = (struct btrfs_ioctl_space_info __user *)
4147                 (arg + sizeof(struct btrfs_ioctl_space_args));
4148
4149         if (copy_to_user(user_dest, dest_orig, alloc_size))
4150                 ret = -EFAULT;
4151
4152         kfree(dest_orig);
4153 out:
4154         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4155                 ret = -EFAULT;
4156
4157         return ret;
4158 }
4159
4160 /*
4161  * there are many ways the trans_start and trans_end ioctls can lead
4162  * to deadlocks.  They should only be used by applications that
4163  * basically own the machine, and have a very in depth understanding
4164  * of all the possible deadlocks and enospc problems.
4165  */
4166 long btrfs_ioctl_trans_end(struct file *file)
4167 {
4168         struct inode *inode = file_inode(file);
4169         struct btrfs_root *root = BTRFS_I(inode)->root;
4170         struct btrfs_trans_handle *trans;
4171
4172         trans = file->private_data;
4173         if (!trans)
4174                 return -EINVAL;
4175         file->private_data = NULL;
4176
4177         btrfs_end_transaction(trans, root);
4178
4179         atomic_dec(&root->fs_info->open_ioctl_trans);
4180
4181         mnt_drop_write_file(file);
4182         return 0;
4183 }
4184
4185 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4186                                             void __user *argp)
4187 {
4188         struct btrfs_trans_handle *trans;
4189         u64 transid;
4190         int ret;
4191
4192         trans = btrfs_attach_transaction_barrier(root);
4193         if (IS_ERR(trans)) {
4194                 if (PTR_ERR(trans) != -ENOENT)
4195                         return PTR_ERR(trans);
4196
4197                 /* No running transaction, don't bother */
4198                 transid = root->fs_info->last_trans_committed;
4199                 goto out;
4200         }
4201         transid = trans->transid;
4202         ret = btrfs_commit_transaction_async(trans, root, 0);
4203         if (ret) {
4204                 btrfs_end_transaction(trans, root);
4205                 return ret;
4206         }
4207 out:
4208         if (argp)
4209                 if (copy_to_user(argp, &transid, sizeof(transid)))
4210                         return -EFAULT;
4211         return 0;
4212 }
4213
4214 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
4215                                            void __user *argp)
4216 {
4217         u64 transid;
4218
4219         if (argp) {
4220                 if (copy_from_user(&transid, argp, sizeof(transid)))
4221                         return -EFAULT;
4222         } else {
4223                 transid = 0;  /* current trans */
4224         }
4225         return btrfs_wait_for_commit(root, transid);
4226 }
4227
4228 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4229 {
4230         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4231         struct btrfs_ioctl_scrub_args *sa;
4232         int ret;
4233
4234         if (!capable(CAP_SYS_ADMIN))
4235                 return -EPERM;
4236
4237         sa = memdup_user(arg, sizeof(*sa));
4238         if (IS_ERR(sa))
4239                 return PTR_ERR(sa);
4240
4241         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4242                 ret = mnt_want_write_file(file);
4243                 if (ret)
4244                         goto out;
4245         }
4246
4247         ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
4248                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4249                               0);
4250
4251         if (copy_to_user(arg, sa, sizeof(*sa)))
4252                 ret = -EFAULT;
4253
4254         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4255                 mnt_drop_write_file(file);
4256 out:
4257         kfree(sa);
4258         return ret;
4259 }
4260
4261 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
4262 {
4263         if (!capable(CAP_SYS_ADMIN))
4264                 return -EPERM;
4265
4266         return btrfs_scrub_cancel(root->fs_info);
4267 }
4268
4269 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
4270                                        void __user *arg)
4271 {
4272         struct btrfs_ioctl_scrub_args *sa;
4273         int ret;
4274
4275         if (!capable(CAP_SYS_ADMIN))
4276                 return -EPERM;
4277
4278         sa = memdup_user(arg, sizeof(*sa));
4279         if (IS_ERR(sa))
4280                 return PTR_ERR(sa);
4281
4282         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
4283
4284         if (copy_to_user(arg, sa, sizeof(*sa)))
4285                 ret = -EFAULT;
4286
4287         kfree(sa);
4288         return ret;
4289 }
4290
4291 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
4292                                       void __user *arg)
4293 {
4294         struct btrfs_ioctl_get_dev_stats *sa;
4295         int ret;
4296
4297         sa = memdup_user(arg, sizeof(*sa));
4298         if (IS_ERR(sa))
4299                 return PTR_ERR(sa);
4300
4301         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4302                 kfree(sa);
4303                 return -EPERM;
4304         }
4305
4306         ret = btrfs_get_dev_stats(root, sa);
4307
4308         if (copy_to_user(arg, sa, sizeof(*sa)))
4309                 ret = -EFAULT;
4310
4311         kfree(sa);
4312         return ret;
4313 }
4314
4315 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
4316 {
4317         struct btrfs_ioctl_dev_replace_args *p;
4318         int ret;
4319
4320         if (!capable(CAP_SYS_ADMIN))
4321                 return -EPERM;
4322
4323         p = memdup_user(arg, sizeof(*p));
4324         if (IS_ERR(p))
4325                 return PTR_ERR(p);
4326
4327         switch (p->cmd) {
4328         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4329                 if (root->fs_info->sb->s_flags & MS_RDONLY) {
4330                         ret = -EROFS;
4331                         goto out;
4332                 }
4333                 if (atomic_xchg(
4334                         &root->fs_info->mutually_exclusive_operation_running,
4335                         1)) {
4336                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4337                 } else {
4338                         ret = btrfs_dev_replace_start(root, p);
4339                         atomic_set(
4340                          &root->fs_info->mutually_exclusive_operation_running,
4341                          0);
4342                 }
4343                 break;
4344         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4345                 btrfs_dev_replace_status(root->fs_info, p);
4346                 ret = 0;
4347                 break;
4348         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4349                 ret = btrfs_dev_replace_cancel(root->fs_info, p);
4350                 break;
4351         default:
4352                 ret = -EINVAL;
4353                 break;
4354         }
4355
4356         if (copy_to_user(arg, p, sizeof(*p)))
4357                 ret = -EFAULT;
4358 out:
4359         kfree(p);
4360         return ret;
4361 }
4362
4363 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4364 {
4365         int ret = 0;
4366         int i;
4367         u64 rel_ptr;
4368         int size;
4369         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4370         struct inode_fs_paths *ipath = NULL;
4371         struct btrfs_path *path;
4372
4373         if (!capable(CAP_DAC_READ_SEARCH))
4374                 return -EPERM;
4375
4376         path = btrfs_alloc_path();
4377         if (!path) {
4378                 ret = -ENOMEM;
4379                 goto out;
4380         }
4381
4382         ipa = memdup_user(arg, sizeof(*ipa));
4383         if (IS_ERR(ipa)) {
4384                 ret = PTR_ERR(ipa);
4385                 ipa = NULL;
4386                 goto out;
4387         }
4388
4389         size = min_t(u32, ipa->size, 4096);
4390         ipath = init_ipath(size, root, path);
4391         if (IS_ERR(ipath)) {
4392                 ret = PTR_ERR(ipath);
4393                 ipath = NULL;
4394                 goto out;
4395         }
4396
4397         ret = paths_from_inode(ipa->inum, ipath);
4398         if (ret < 0)
4399                 goto out;
4400
4401         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4402                 rel_ptr = ipath->fspath->val[i] -
4403                           (u64)(unsigned long)ipath->fspath->val;
4404                 ipath->fspath->val[i] = rel_ptr;
4405         }
4406
4407         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4408                            (void *)(unsigned long)ipath->fspath, size);
4409         if (ret) {
4410                 ret = -EFAULT;
4411                 goto out;
4412         }
4413
4414 out:
4415         btrfs_free_path(path);
4416         free_ipath(ipath);
4417         kfree(ipa);
4418
4419         return ret;
4420 }
4421
4422 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4423 {
4424         struct btrfs_data_container *inodes = ctx;
4425         const size_t c = 3 * sizeof(u64);
4426
4427         if (inodes->bytes_left >= c) {
4428                 inodes->bytes_left -= c;
4429                 inodes->val[inodes->elem_cnt] = inum;
4430                 inodes->val[inodes->elem_cnt + 1] = offset;
4431                 inodes->val[inodes->elem_cnt + 2] = root;
4432                 inodes->elem_cnt += 3;
4433         } else {
4434                 inodes->bytes_missing += c - inodes->bytes_left;
4435                 inodes->bytes_left = 0;
4436                 inodes->elem_missed += 3;
4437         }
4438
4439         return 0;
4440 }
4441
4442 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
4443                                         void __user *arg)
4444 {
4445         int ret = 0;
4446         int size;
4447         struct btrfs_ioctl_logical_ino_args *loi;
4448         struct btrfs_data_container *inodes = NULL;
4449         struct btrfs_path *path = NULL;
4450
4451         if (!capable(CAP_SYS_ADMIN))
4452                 return -EPERM;
4453
4454         loi = memdup_user(arg, sizeof(*loi));
4455         if (IS_ERR(loi)) {
4456                 ret = PTR_ERR(loi);
4457                 loi = NULL;
4458                 goto out;
4459         }
4460
4461         path = btrfs_alloc_path();
4462         if (!path) {
4463                 ret = -ENOMEM;
4464                 goto out;
4465         }
4466
4467         size = min_t(u32, loi->size, 64 * 1024);
4468         inodes = init_data_container(size);
4469         if (IS_ERR(inodes)) {
4470                 ret = PTR_ERR(inodes);
4471                 inodes = NULL;
4472                 goto out;
4473         }
4474
4475         ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
4476                                           build_ino_list, inodes);
4477         if (ret == -EINVAL)
4478                 ret = -ENOENT;
4479         if (ret < 0)
4480                 goto out;
4481
4482         ret = copy_to_user((void *)(unsigned long)loi->inodes,
4483                            (void *)(unsigned long)inodes, size);
4484         if (ret)
4485                 ret = -EFAULT;
4486
4487 out:
4488         btrfs_free_path(path);
4489         vfree(inodes);
4490         kfree(loi);
4491
4492         return ret;
4493 }
4494
4495 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4496                                struct btrfs_ioctl_balance_args *bargs)
4497 {
4498         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4499
4500         bargs->flags = bctl->flags;
4501
4502         if (atomic_read(&fs_info->balance_running))
4503                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4504         if (atomic_read(&fs_info->balance_pause_req))
4505                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4506         if (atomic_read(&fs_info->balance_cancel_req))
4507                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4508
4509         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4510         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4511         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4512
4513         if (lock) {
4514                 spin_lock(&fs_info->balance_lock);
4515                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4516                 spin_unlock(&fs_info->balance_lock);
4517         } else {
4518                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4519         }
4520 }
4521
4522 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4523 {
4524         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4525         struct btrfs_fs_info *fs_info = root->fs_info;
4526         struct btrfs_ioctl_balance_args *bargs;
4527         struct btrfs_balance_control *bctl;
4528         bool need_unlock; /* for mut. excl. ops lock */
4529         int ret;
4530
4531         if (!capable(CAP_SYS_ADMIN))
4532                 return -EPERM;
4533
4534         ret = mnt_want_write_file(file);
4535         if (ret)
4536                 return ret;
4537
4538 again:
4539         if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
4540                 mutex_lock(&fs_info->volume_mutex);
4541                 mutex_lock(&fs_info->balance_mutex);
4542                 need_unlock = true;
4543                 goto locked;
4544         }
4545
4546         /*
4547          * mut. excl. ops lock is locked.  Three possibilites:
4548          *   (1) some other op is running
4549          *   (2) balance is running
4550          *   (3) balance is paused -- special case (think resume)
4551          */
4552         mutex_lock(&fs_info->balance_mutex);
4553         if (fs_info->balance_ctl) {
4554                 /* this is either (2) or (3) */
4555                 if (!atomic_read(&fs_info->balance_running)) {
4556                         mutex_unlock(&fs_info->balance_mutex);
4557                         if (!mutex_trylock(&fs_info->volume_mutex))
4558                                 goto again;
4559                         mutex_lock(&fs_info->balance_mutex);
4560
4561                         if (fs_info->balance_ctl &&
4562                             !atomic_read(&fs_info->balance_running)) {
4563                                 /* this is (3) */
4564                                 need_unlock = false;
4565                                 goto locked;
4566                         }
4567
4568                         mutex_unlock(&fs_info->balance_mutex);
4569                         mutex_unlock(&fs_info->volume_mutex);
4570                         goto again;
4571                 } else {
4572                         /* this is (2) */
4573                         mutex_unlock(&fs_info->balance_mutex);
4574                         ret = -EINPROGRESS;
4575                         goto out;
4576                 }
4577         } else {
4578                 /* this is (1) */
4579                 mutex_unlock(&fs_info->balance_mutex);
4580                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4581                 goto out;
4582         }
4583
4584 locked:
4585         BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
4586
4587         if (arg) {
4588                 bargs = memdup_user(arg, sizeof(*bargs));
4589                 if (IS_ERR(bargs)) {
4590                         ret = PTR_ERR(bargs);
4591                         goto out_unlock;
4592                 }
4593
4594                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4595                         if (!fs_info->balance_ctl) {
4596                                 ret = -ENOTCONN;
4597                                 goto out_bargs;
4598                         }
4599
4600                         bctl = fs_info->balance_ctl;
4601                         spin_lock(&fs_info->balance_lock);
4602                         bctl->flags |= BTRFS_BALANCE_RESUME;
4603                         spin_unlock(&fs_info->balance_lock);
4604
4605                         goto do_balance;
4606                 }
4607         } else {
4608                 bargs = NULL;
4609         }
4610
4611         if (fs_info->balance_ctl) {
4612                 ret = -EINPROGRESS;
4613                 goto out_bargs;
4614         }
4615
4616         bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
4617         if (!bctl) {
4618                 ret = -ENOMEM;
4619                 goto out_bargs;
4620         }
4621
4622         bctl->fs_info = fs_info;
4623         if (arg) {
4624                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4625                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4626                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4627
4628                 bctl->flags = bargs->flags;
4629         } else {
4630                 /* balance everything - no filters */
4631                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4632         }
4633
4634 do_balance:
4635         /*
4636          * Ownership of bctl and mutually_exclusive_operation_running
4637          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4638          * or, if restriper was paused all the way until unmount, in
4639          * free_fs_info.  mutually_exclusive_operation_running is
4640          * cleared in __cancel_balance.
4641          */
4642         need_unlock = false;
4643
4644         ret = btrfs_balance(bctl, bargs);
4645
4646         if (arg) {
4647                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4648                         ret = -EFAULT;
4649         }
4650
4651 out_bargs:
4652         kfree(bargs);
4653 out_unlock:
4654         mutex_unlock(&fs_info->balance_mutex);
4655         mutex_unlock(&fs_info->volume_mutex);
4656         if (need_unlock)
4657                 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
4658 out:
4659         mnt_drop_write_file(file);
4660         return ret;
4661 }
4662
4663 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
4664 {
4665         if (!capable(CAP_SYS_ADMIN))
4666                 return -EPERM;
4667
4668         switch (cmd) {
4669         case BTRFS_BALANCE_CTL_PAUSE:
4670                 return btrfs_pause_balance(root->fs_info);
4671         case BTRFS_BALANCE_CTL_CANCEL:
4672                 return btrfs_cancel_balance(root->fs_info);
4673         }
4674
4675         return -EINVAL;
4676 }
4677
4678 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
4679                                          void __user *arg)
4680 {
4681         struct btrfs_fs_info *fs_info = root->fs_info;
4682         struct btrfs_ioctl_balance_args *bargs;
4683         int ret = 0;
4684
4685         if (!capable(CAP_SYS_ADMIN))
4686                 return -EPERM;
4687
4688         mutex_lock(&fs_info->balance_mutex);
4689         if (!fs_info->balance_ctl) {
4690                 ret = -ENOTCONN;
4691                 goto out;
4692         }
4693
4694         bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
4695         if (!bargs) {
4696                 ret = -ENOMEM;
4697                 goto out;
4698         }
4699
4700         update_ioctl_balance_args(fs_info, 1, bargs);
4701
4702         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4703                 ret = -EFAULT;
4704
4705         kfree(bargs);
4706 out:
4707         mutex_unlock(&fs_info->balance_mutex);
4708         return ret;
4709 }
4710
4711 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4712 {
4713         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4714         struct btrfs_ioctl_quota_ctl_args *sa;
4715         struct btrfs_trans_handle *trans = NULL;
4716         int ret;
4717         int err;
4718
4719         if (!capable(CAP_SYS_ADMIN))
4720                 return -EPERM;
4721
4722         ret = mnt_want_write_file(file);
4723         if (ret)
4724                 return ret;
4725
4726         sa = memdup_user(arg, sizeof(*sa));
4727         if (IS_ERR(sa)) {
4728                 ret = PTR_ERR(sa);
4729                 goto drop_write;
4730         }
4731
4732         down_write(&root->fs_info->subvol_sem);
4733         trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
4734         if (IS_ERR(trans)) {
4735                 ret = PTR_ERR(trans);
4736                 goto out;
4737         }
4738
4739         switch (sa->cmd) {
4740         case BTRFS_QUOTA_CTL_ENABLE:
4741                 ret = btrfs_quota_enable(trans, root->fs_info);
4742                 break;
4743         case BTRFS_QUOTA_CTL_DISABLE:
4744                 ret = btrfs_quota_disable(trans, root->fs_info);
4745                 break;
4746         default:
4747                 ret = -EINVAL;
4748                 break;
4749         }
4750
4751         err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
4752         if (err && !ret)
4753                 ret = err;
4754 out:
4755         kfree(sa);
4756         up_write(&root->fs_info->subvol_sem);
4757 drop_write:
4758         mnt_drop_write_file(file);
4759         return ret;
4760 }
4761
4762 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4763 {
4764         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4765         struct btrfs_ioctl_qgroup_assign_args *sa;
4766         struct btrfs_trans_handle *trans;
4767         int ret;
4768         int err;
4769
4770         if (!capable(CAP_SYS_ADMIN))
4771                 return -EPERM;
4772
4773         ret = mnt_want_write_file(file);
4774         if (ret)
4775                 return ret;
4776
4777         sa = memdup_user(arg, sizeof(*sa));
4778         if (IS_ERR(sa)) {
4779                 ret = PTR_ERR(sa);
4780                 goto drop_write;
4781         }
4782
4783         trans = btrfs_join_transaction(root);
4784         if (IS_ERR(trans)) {
4785                 ret = PTR_ERR(trans);
4786                 goto out;
4787         }
4788
4789         /* FIXME: check if the IDs really exist */
4790         if (sa->assign) {
4791                 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
4792                                                 sa->src, sa->dst);
4793         } else {
4794                 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
4795                                                 sa->src, sa->dst);
4796         }
4797
4798         /* update qgroup status and info */
4799         err = btrfs_run_qgroups(trans, root->fs_info);
4800         if (err < 0)
4801                 btrfs_error(root->fs_info, ret,
4802                             "failed to update qgroup status and info\n");
4803         err = btrfs_end_transaction(trans, root);
4804         if (err && !ret)
4805                 ret = err;
4806
4807 out:
4808         kfree(sa);
4809 drop_write:
4810         mnt_drop_write_file(file);
4811         return ret;
4812 }
4813
4814 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4815 {
4816         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4817         struct btrfs_ioctl_qgroup_create_args *sa;
4818         struct btrfs_trans_handle *trans;
4819         int ret;
4820         int err;
4821
4822         if (!capable(CAP_SYS_ADMIN))
4823                 return -EPERM;
4824
4825         ret = mnt_want_write_file(file);
4826         if (ret)
4827                 return ret;
4828
4829         sa = memdup_user(arg, sizeof(*sa));
4830         if (IS_ERR(sa)) {
4831                 ret = PTR_ERR(sa);
4832                 goto drop_write;
4833         }
4834
4835         if (!sa->qgroupid) {
4836                 ret = -EINVAL;
4837                 goto out;
4838         }
4839
4840         trans = btrfs_join_transaction(root);
4841         if (IS_ERR(trans)) {
4842                 ret = PTR_ERR(trans);
4843                 goto out;
4844         }
4845
4846         /* FIXME: check if the IDs really exist */
4847         if (sa->create) {
4848                 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid);
4849         } else {
4850                 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
4851         }
4852
4853         err = btrfs_end_transaction(trans, root);
4854         if (err && !ret)
4855                 ret = err;
4856
4857 out:
4858         kfree(sa);
4859 drop_write:
4860         mnt_drop_write_file(file);
4861         return ret;
4862 }
4863
4864 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4865 {
4866         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4867         struct btrfs_ioctl_qgroup_limit_args *sa;
4868         struct btrfs_trans_handle *trans;
4869         int ret;
4870         int err;
4871         u64 qgroupid;
4872
4873         if (!capable(CAP_SYS_ADMIN))
4874                 return -EPERM;
4875
4876         ret = mnt_want_write_file(file);
4877         if (ret)
4878                 return ret;
4879
4880         sa = memdup_user(arg, sizeof(*sa));
4881         if (IS_ERR(sa)) {
4882                 ret = PTR_ERR(sa);
4883                 goto drop_write;
4884         }
4885
4886         trans = btrfs_join_transaction(root);
4887         if (IS_ERR(trans)) {
4888                 ret = PTR_ERR(trans);
4889                 goto out;
4890         }
4891
4892         qgroupid = sa->qgroupid;
4893         if (!qgroupid) {
4894                 /* take the current subvol as qgroup */
4895                 qgroupid = root->root_key.objectid;
4896         }
4897
4898         /* FIXME: check if the IDs really exist */
4899         ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
4900
4901         err = btrfs_end_transaction(trans, root);
4902         if (err && !ret)
4903                 ret = err;
4904
4905 out:
4906         kfree(sa);
4907 drop_write:
4908         mnt_drop_write_file(file);
4909         return ret;
4910 }
4911
4912 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4913 {
4914         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4915         struct btrfs_ioctl_quota_rescan_args *qsa;
4916         int ret;
4917
4918         if (!capable(CAP_SYS_ADMIN))
4919                 return -EPERM;
4920
4921         ret = mnt_want_write_file(file);
4922         if (ret)
4923                 return ret;
4924
4925         qsa = memdup_user(arg, sizeof(*qsa));
4926         if (IS_ERR(qsa)) {
4927                 ret = PTR_ERR(qsa);
4928                 goto drop_write;
4929         }
4930
4931         if (qsa->flags) {
4932                 ret = -EINVAL;
4933                 goto out;
4934         }
4935
4936         ret = btrfs_qgroup_rescan(root->fs_info);
4937
4938 out:
4939         kfree(qsa);
4940 drop_write:
4941         mnt_drop_write_file(file);
4942         return ret;
4943 }
4944
4945 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
4946 {
4947         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4948         struct btrfs_ioctl_quota_rescan_args *qsa;
4949         int ret = 0;
4950
4951         if (!capable(CAP_SYS_ADMIN))
4952                 return -EPERM;
4953
4954         qsa = kzalloc(sizeof(*qsa), GFP_NOFS);
4955         if (!qsa)
4956                 return -ENOMEM;
4957
4958         if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4959                 qsa->flags = 1;
4960                 qsa->progress = root->fs_info->qgroup_rescan_progress.objectid;
4961         }
4962
4963         if (copy_to_user(arg, qsa, sizeof(*qsa)))
4964                 ret = -EFAULT;
4965
4966         kfree(qsa);
4967         return ret;
4968 }
4969
4970 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
4971 {
4972         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4973
4974         if (!capable(CAP_SYS_ADMIN))
4975                 return -EPERM;
4976
4977         return btrfs_qgroup_wait_for_completion(root->fs_info);
4978 }
4979
4980 static long _btrfs_ioctl_set_received_subvol(struct file *file,
4981                                             struct btrfs_ioctl_received_subvol_args *sa)
4982 {
4983         struct inode *inode = file_inode(file);
4984         struct btrfs_root *root = BTRFS_I(inode)->root;
4985         struct btrfs_root_item *root_item = &root->root_item;
4986         struct btrfs_trans_handle *trans;
4987         struct timespec ct = CURRENT_TIME;
4988         int ret = 0;
4989         int received_uuid_changed;
4990
4991         if (!inode_owner_or_capable(inode))
4992                 return -EPERM;
4993
4994         ret = mnt_want_write_file(file);
4995         if (ret < 0)
4996                 return ret;
4997
4998         down_write(&root->fs_info->subvol_sem);
4999
5000         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
5001                 ret = -EINVAL;
5002                 goto out;
5003         }
5004
5005         if (btrfs_root_readonly(root)) {
5006                 ret = -EROFS;
5007                 goto out;
5008         }
5009
5010         /*
5011          * 1 - root item
5012          * 2 - uuid items (received uuid + subvol uuid)
5013          */
5014         trans = btrfs_start_transaction(root, 3);
5015         if (IS_ERR(trans)) {
5016                 ret = PTR_ERR(trans);
5017                 trans = NULL;
5018                 goto out;
5019         }
5020
5021         sa->rtransid = trans->transid;
5022         sa->rtime.sec = ct.tv_sec;
5023         sa->rtime.nsec = ct.tv_nsec;
5024
5025         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5026                                        BTRFS_UUID_SIZE);
5027         if (received_uuid_changed &&
5028             !btrfs_is_empty_uuid(root_item->received_uuid))
5029                 btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
5030                                     root_item->received_uuid,
5031                                     BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5032                                     root->root_key.objectid);
5033         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5034         btrfs_set_root_stransid(root_item, sa->stransid);
5035         btrfs_set_root_rtransid(root_item, sa->rtransid);
5036         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5037         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5038         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5039         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5040
5041         ret = btrfs_update_root(trans, root->fs_info->tree_root,
5042                                 &root->root_key, &root->root_item);
5043         if (ret < 0) {
5044                 btrfs_end_transaction(trans, root);
5045                 goto out;
5046         }
5047         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5048                 ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
5049                                           sa->uuid,
5050                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5051                                           root->root_key.objectid);
5052                 if (ret < 0 && ret != -EEXIST) {
5053                         btrfs_abort_transaction(trans, root, ret);
5054                         goto out;
5055                 }
5056         }
5057         ret = btrfs_commit_transaction(trans, root);
5058         if (ret < 0) {
5059                 btrfs_abort_transaction(trans, root, ret);
5060                 goto out;
5061         }
5062
5063 out:
5064         up_write(&root->fs_info->subvol_sem);
5065         mnt_drop_write_file(file);
5066         return ret;
5067 }
5068
5069 #ifdef CONFIG_64BIT
5070 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5071                                                 void __user *arg)
5072 {
5073         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5074         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5075         int ret = 0;
5076
5077         args32 = memdup_user(arg, sizeof(*args32));
5078         if (IS_ERR(args32)) {
5079                 ret = PTR_ERR(args32);
5080                 args32 = NULL;
5081                 goto out;
5082         }
5083
5084         args64 = kmalloc(sizeof(*args64), GFP_NOFS);
5085         if (!args64) {
5086                 ret = -ENOMEM;
5087                 goto out;
5088         }
5089
5090         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5091         args64->stransid = args32->stransid;
5092         args64->rtransid = args32->rtransid;
5093         args64->stime.sec = args32->stime.sec;
5094         args64->stime.nsec = args32->stime.nsec;
5095         args64->rtime.sec = args32->rtime.sec;
5096         args64->rtime.nsec = args32->rtime.nsec;
5097         args64->flags = args32->flags;
5098
5099         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5100         if (ret)
5101                 goto out;
5102
5103         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5104         args32->stransid = args64->stransid;
5105         args32->rtransid = args64->rtransid;
5106         args32->stime.sec = args64->stime.sec;
5107         args32->stime.nsec = args64->stime.nsec;
5108         args32->rtime.sec = args64->rtime.sec;
5109         args32->rtime.nsec = args64->rtime.nsec;
5110         args32->flags = args64->flags;
5111
5112         ret = copy_to_user(arg, args32, sizeof(*args32));
5113         if (ret)
5114                 ret = -EFAULT;
5115
5116 out:
5117         kfree(args32);
5118         kfree(args64);
5119         return ret;
5120 }
5121 #endif
5122
5123 static long btrfs_ioctl_set_received_subvol(struct file *file,
5124                                             void __user *arg)
5125 {
5126         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5127         int ret = 0;
5128
5129         sa = memdup_user(arg, sizeof(*sa));
5130         if (IS_ERR(sa)) {
5131                 ret = PTR_ERR(sa);
5132                 sa = NULL;
5133                 goto out;
5134         }
5135
5136         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5137
5138         if (ret)
5139                 goto out;
5140
5141         ret = copy_to_user(arg, sa, sizeof(*sa));
5142         if (ret)
5143                 ret = -EFAULT;
5144
5145 out:
5146         kfree(sa);
5147         return ret;
5148 }
5149
5150 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5151 {
5152         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5153         size_t len;
5154         int ret;
5155         char label[BTRFS_LABEL_SIZE];
5156
5157         spin_lock(&root->fs_info->super_lock);
5158         memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5159         spin_unlock(&root->fs_info->super_lock);
5160
5161         len = strnlen(label, BTRFS_LABEL_SIZE);
5162
5163         if (len == BTRFS_LABEL_SIZE) {
5164                 btrfs_warn(root->fs_info,
5165                         "label is too long, return the first %zu bytes", --len);
5166         }
5167
5168         ret = copy_to_user(arg, label, len);
5169
5170         return ret ? -EFAULT : 0;
5171 }
5172
5173 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5174 {
5175         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5176         struct btrfs_super_block *super_block = root->fs_info->super_copy;
5177         struct btrfs_trans_handle *trans;
5178         char label[BTRFS_LABEL_SIZE];
5179         int ret;
5180
5181         if (!capable(CAP_SYS_ADMIN))
5182                 return -EPERM;
5183
5184         if (copy_from_user(label, arg, sizeof(label)))
5185                 return -EFAULT;
5186
5187         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5188                 btrfs_err(root->fs_info, "unable to set label with more than %d bytes",
5189                        BTRFS_LABEL_SIZE - 1);
5190                 return -EINVAL;
5191         }
5192
5193         ret = mnt_want_write_file(file);
5194         if (ret)
5195                 return ret;
5196
5197         trans = btrfs_start_transaction(root, 0);
5198         if (IS_ERR(trans)) {
5199                 ret = PTR_ERR(trans);
5200                 goto out_unlock;
5201         }
5202
5203         spin_lock(&root->fs_info->super_lock);
5204         strcpy(super_block->label, label);
5205         spin_unlock(&root->fs_info->super_lock);
5206         ret = btrfs_commit_transaction(trans, root);
5207
5208 out_unlock:
5209         mnt_drop_write_file(file);
5210         return ret;
5211 }
5212
5213 #define INIT_FEATURE_FLAGS(suffix) \
5214         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5215           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5216           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5217
5218 static int btrfs_ioctl_get_supported_features(struct file *file,
5219                                               void __user *arg)
5220 {
5221         static struct btrfs_ioctl_feature_flags features[3] = {
5222                 INIT_FEATURE_FLAGS(SUPP),
5223                 INIT_FEATURE_FLAGS(SAFE_SET),
5224                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5225         };
5226
5227         if (copy_to_user(arg, &features, sizeof(features)))
5228                 return -EFAULT;
5229
5230         return 0;
5231 }
5232
5233 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5234 {
5235         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5236         struct btrfs_super_block *super_block = root->fs_info->super_copy;
5237         struct btrfs_ioctl_feature_flags features;
5238
5239         features.compat_flags = btrfs_super_compat_flags(super_block);
5240         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5241         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5242
5243         if (copy_to_user(arg, &features, sizeof(features)))
5244                 return -EFAULT;
5245
5246         return 0;
5247 }
5248
5249 static int check_feature_bits(struct btrfs_root *root,
5250                               enum btrfs_feature_set set,
5251                               u64 change_mask, u64 flags, u64 supported_flags,
5252                               u64 safe_set, u64 safe_clear)
5253 {
5254         const char *type = btrfs_feature_set_names[set];
5255         char *names;
5256         u64 disallowed, unsupported;
5257         u64 set_mask = flags & change_mask;
5258         u64 clear_mask = ~flags & change_mask;
5259
5260         unsupported = set_mask & ~supported_flags;
5261         if (unsupported) {
5262                 names = btrfs_printable_features(set, unsupported);
5263                 if (names) {
5264                         btrfs_warn(root->fs_info,
5265                            "this kernel does not support the %s feature bit%s",
5266                            names, strchr(names, ',') ? "s" : "");
5267                         kfree(names);
5268                 } else
5269                         btrfs_warn(root->fs_info,
5270                            "this kernel does not support %s bits 0x%llx",
5271                            type, unsupported);
5272                 return -EOPNOTSUPP;
5273         }
5274
5275         disallowed = set_mask & ~safe_set;
5276         if (disallowed) {
5277                 names = btrfs_printable_features(set, disallowed);
5278                 if (names) {
5279                         btrfs_warn(root->fs_info,
5280                            "can't set the %s feature bit%s while mounted",
5281                            names, strchr(names, ',') ? "s" : "");
5282                         kfree(names);
5283                 } else
5284                         btrfs_warn(root->fs_info,
5285                            "can't set %s bits 0x%llx while mounted",
5286                            type, disallowed);
5287                 return -EPERM;
5288         }
5289
5290         disallowed = clear_mask & ~safe_clear;
5291         if (disallowed) {
5292                 names = btrfs_printable_features(set, disallowed);
5293                 if (names) {
5294                         btrfs_warn(root->fs_info,
5295                            "can't clear the %s feature bit%s while mounted",
5296                            names, strchr(names, ',') ? "s" : "");
5297                         kfree(names);
5298                 } else
5299                         btrfs_warn(root->fs_info,
5300                            "can't clear %s bits 0x%llx while mounted",
5301                            type, disallowed);
5302                 return -EPERM;
5303         }
5304
5305         return 0;
5306 }
5307
5308 #define check_feature(root, change_mask, flags, mask_base)      \
5309 check_feature_bits(root, FEAT_##mask_base, change_mask, flags,  \
5310                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5311                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5312                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5313
5314 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5315 {
5316         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5317         struct btrfs_super_block *super_block = root->fs_info->super_copy;
5318         struct btrfs_ioctl_feature_flags flags[2];
5319         struct btrfs_trans_handle *trans;
5320         u64 newflags;
5321         int ret;
5322
5323         if (!capable(CAP_SYS_ADMIN))
5324                 return -EPERM;
5325
5326         if (copy_from_user(flags, arg, sizeof(flags)))
5327                 return -EFAULT;
5328
5329         /* Nothing to do */
5330         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5331             !flags[0].incompat_flags)
5332                 return 0;
5333
5334         ret = check_feature(root, flags[0].compat_flags,
5335                             flags[1].compat_flags, COMPAT);
5336         if (ret)
5337                 return ret;
5338
5339         ret = check_feature(root, flags[0].compat_ro_flags,
5340                             flags[1].compat_ro_flags, COMPAT_RO);
5341         if (ret)
5342                 return ret;
5343
5344         ret = check_feature(root, flags[0].incompat_flags,
5345                             flags[1].incompat_flags, INCOMPAT);
5346         if (ret)
5347                 return ret;
5348
5349         trans = btrfs_start_transaction(root, 0);
5350         if (IS_ERR(trans))
5351                 return PTR_ERR(trans);
5352
5353         spin_lock(&root->fs_info->super_lock);
5354         newflags = btrfs_super_compat_flags(super_block);
5355         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5356         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5357         btrfs_set_super_compat_flags(super_block, newflags);
5358
5359         newflags = btrfs_super_compat_ro_flags(super_block);
5360         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5361         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5362         btrfs_set_super_compat_ro_flags(super_block, newflags);
5363
5364         newflags = btrfs_super_incompat_flags(super_block);
5365         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5366         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5367         btrfs_set_super_incompat_flags(super_block, newflags);
5368         spin_unlock(&root->fs_info->super_lock);
5369
5370         return btrfs_commit_transaction(trans, root);
5371 }
5372
5373 long btrfs_ioctl(struct file *file, unsigned int
5374                 cmd, unsigned long arg)
5375 {
5376         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5377         void __user *argp = (void __user *)arg;
5378
5379         switch (cmd) {
5380         case FS_IOC_GETFLAGS:
5381                 return btrfs_ioctl_getflags(file, argp);
5382         case FS_IOC_SETFLAGS:
5383                 return btrfs_ioctl_setflags(file, argp);
5384         case FS_IOC_GETVERSION:
5385                 return btrfs_ioctl_getversion(file, argp);
5386         case FITRIM:
5387                 return btrfs_ioctl_fitrim(file, argp);
5388         case BTRFS_IOC_SNAP_CREATE:
5389                 return btrfs_ioctl_snap_create(file, argp, 0);
5390         case BTRFS_IOC_SNAP_CREATE_V2:
5391                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5392         case BTRFS_IOC_SUBVOL_CREATE:
5393                 return btrfs_ioctl_snap_create(file, argp, 1);
5394         case BTRFS_IOC_SUBVOL_CREATE_V2:
5395                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5396         case BTRFS_IOC_SNAP_DESTROY:
5397                 return btrfs_ioctl_snap_destroy(file, argp);
5398         case BTRFS_IOC_SUBVOL_GETFLAGS:
5399                 return btrfs_ioctl_subvol_getflags(file, argp);
5400         case BTRFS_IOC_SUBVOL_SETFLAGS:
5401                 return btrfs_ioctl_subvol_setflags(file, argp);
5402         case BTRFS_IOC_DEFAULT_SUBVOL:
5403                 return btrfs_ioctl_default_subvol(file, argp);
5404         case BTRFS_IOC_DEFRAG:
5405                 return btrfs_ioctl_defrag(file, NULL);
5406         case BTRFS_IOC_DEFRAG_RANGE:
5407                 return btrfs_ioctl_defrag(file, argp);
5408         case BTRFS_IOC_RESIZE:
5409                 return btrfs_ioctl_resize(file, argp);
5410         case BTRFS_IOC_ADD_DEV:
5411                 return btrfs_ioctl_add_dev(root, argp);
5412         case BTRFS_IOC_RM_DEV:
5413                 return btrfs_ioctl_rm_dev(file, argp);
5414         case BTRFS_IOC_FS_INFO:
5415                 return btrfs_ioctl_fs_info(root, argp);
5416         case BTRFS_IOC_DEV_INFO:
5417                 return btrfs_ioctl_dev_info(root, argp);
5418         case BTRFS_IOC_BALANCE:
5419                 return btrfs_ioctl_balance(file, NULL);
5420         case BTRFS_IOC_CLONE:
5421                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
5422         case BTRFS_IOC_CLONE_RANGE:
5423                 return btrfs_ioctl_clone_range(file, argp);
5424         case BTRFS_IOC_TRANS_START:
5425                 return btrfs_ioctl_trans_start(file);
5426         case BTRFS_IOC_TRANS_END:
5427                 return btrfs_ioctl_trans_end(file);
5428         case BTRFS_IOC_TREE_SEARCH:
5429                 return btrfs_ioctl_tree_search(file, argp);
5430         case BTRFS_IOC_TREE_SEARCH_V2:
5431                 return btrfs_ioctl_tree_search_v2(file, argp);
5432         case BTRFS_IOC_INO_LOOKUP:
5433                 return btrfs_ioctl_ino_lookup(file, argp);
5434         case BTRFS_IOC_INO_PATHS:
5435                 return btrfs_ioctl_ino_to_path(root, argp);
5436         case BTRFS_IOC_LOGICAL_INO:
5437                 return btrfs_ioctl_logical_to_ino(root, argp);
5438         case BTRFS_IOC_SPACE_INFO:
5439                 return btrfs_ioctl_space_info(root, argp);
5440         case BTRFS_IOC_SYNC: {
5441                 int ret;
5442
5443                 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1);
5444                 if (ret)
5445                         return ret;
5446                 ret = btrfs_sync_fs(file_inode(file)->i_sb, 1);
5447                 /*
5448                  * The transaction thread may want to do more work,
5449                  * namely it pokes the cleaner ktread that will start
5450                  * processing uncleaned subvols.
5451                  */
5452                 wake_up_process(root->fs_info->transaction_kthread);
5453                 return ret;
5454         }
5455         case BTRFS_IOC_START_SYNC:
5456                 return btrfs_ioctl_start_sync(root, argp);
5457         case BTRFS_IOC_WAIT_SYNC:
5458                 return btrfs_ioctl_wait_sync(root, argp);
5459         case BTRFS_IOC_SCRUB:
5460                 return btrfs_ioctl_scrub(file, argp);
5461         case BTRFS_IOC_SCRUB_CANCEL:
5462                 return btrfs_ioctl_scrub_cancel(root, argp);
5463         case BTRFS_IOC_SCRUB_PROGRESS:
5464                 return btrfs_ioctl_scrub_progress(root, argp);
5465         case BTRFS_IOC_BALANCE_V2:
5466                 return btrfs_ioctl_balance(file, argp);
5467         case BTRFS_IOC_BALANCE_CTL:
5468                 return btrfs_ioctl_balance_ctl(root, arg);
5469         case BTRFS_IOC_BALANCE_PROGRESS:
5470                 return btrfs_ioctl_balance_progress(root, argp);
5471         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5472                 return btrfs_ioctl_set_received_subvol(file, argp);
5473 #ifdef CONFIG_64BIT
5474         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5475                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5476 #endif
5477         case BTRFS_IOC_SEND:
5478                 return btrfs_ioctl_send(file, argp);
5479         case BTRFS_IOC_GET_DEV_STATS:
5480                 return btrfs_ioctl_get_dev_stats(root, argp);
5481         case BTRFS_IOC_QUOTA_CTL:
5482                 return btrfs_ioctl_quota_ctl(file, argp);
5483         case BTRFS_IOC_QGROUP_ASSIGN:
5484                 return btrfs_ioctl_qgroup_assign(file, argp);
5485         case BTRFS_IOC_QGROUP_CREATE:
5486                 return btrfs_ioctl_qgroup_create(file, argp);
5487         case BTRFS_IOC_QGROUP_LIMIT:
5488                 return btrfs_ioctl_qgroup_limit(file, argp);
5489         case BTRFS_IOC_QUOTA_RESCAN:
5490                 return btrfs_ioctl_quota_rescan(file, argp);
5491         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5492                 return btrfs_ioctl_quota_rescan_status(file, argp);
5493         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5494                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5495         case BTRFS_IOC_DEV_REPLACE:
5496                 return btrfs_ioctl_dev_replace(root, argp);
5497         case BTRFS_IOC_GET_FSLABEL:
5498                 return btrfs_ioctl_get_fslabel(file, argp);
5499         case BTRFS_IOC_SET_FSLABEL:
5500                 return btrfs_ioctl_set_fslabel(file, argp);
5501         case BTRFS_IOC_FILE_EXTENT_SAME:
5502                 return btrfs_ioctl_file_extent_same(file, argp);
5503         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5504                 return btrfs_ioctl_get_supported_features(file, argp);
5505         case BTRFS_IOC_GET_FEATURES:
5506                 return btrfs_ioctl_get_features(file, argp);
5507         case BTRFS_IOC_SET_FEATURES:
5508                 return btrfs_ioctl_set_features(file, argp);
5509         }
5510
5511         return -ENOTTY;
5512 }