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 "compat.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
  60 /* Mask out flags that are inappropriate for the given type of inode. */
  61 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  62 {
  63         if (S_ISDIR(mode))
  64                 return flags;
  65         else if (S_ISREG(mode))
  66                 return flags & ~FS_DIRSYNC_FL;
  67         else
  68                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  69 }
  70
  71 /*
  72  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  73  */
  74 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  75 {
  76         unsigned int iflags = 0;
  77
  78         if (flags & BTRFS_INODE_SYNC)
  79                 iflags |= FS_SYNC_FL;
  80         if (flags & BTRFS_INODE_IMMUTABLE)
  81                 iflags |= FS_IMMUTABLE_FL;
  82         if (flags & BTRFS_INODE_APPEND)
  83                 iflags |= FS_APPEND_FL;
  84         if (flags & BTRFS_INODE_NODUMP)
  85                 iflags |= FS_NODUMP_FL;
  86         if (flags & BTRFS_INODE_NOATIME)
  87                 iflags |= FS_NOATIME_FL;
  88         if (flags & BTRFS_INODE_DIRSYNC)
  89                 iflags |= FS_DIRSYNC_FL;
  90         if (flags & BTRFS_INODE_NODATACOW)
  91                 iflags |= FS_NOCOW_FL;
  92
  93         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
  94                 iflags |= FS_COMPR_FL;
  95         else if (flags & BTRFS_INODE_NOCOMPRESS)
  96                 iflags |= FS_NOCOMP_FL;
  97
  98         return iflags;
  99 }
 100
 101 /*
 102  * Update inode->i_flags based on the btrfs internal flags.
 103  */
 104 void btrfs_update_iflags(struct inode *inode)
 105 {
 106         struct btrfs_inode *ip = BTRFS_I(inode);
 107
 108         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 109
 110         if (ip->flags & BTRFS_INODE_SYNC)
 111                 inode->i_flags |= S_SYNC;
 112         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 113                 inode->i_flags |= S_IMMUTABLE;
 114         if (ip->flags & BTRFS_INODE_APPEND)
 115                 inode->i_flags |= S_APPEND;
 116         if (ip->flags & BTRFS_INODE_NOATIME)
 117                 inode->i_flags |= S_NOATIME;
 118         if (ip->flags & BTRFS_INODE_DIRSYNC)
 119                 inode->i_flags |= S_DIRSYNC;
 120 }
 121
 122 /*
 123  * Inherit flags from the parent inode.
 124  *
 125  * Currently only the compression flags and the cow flags are inherited.
 126  */
 127 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 128 {
 129         unsigned int flags;
 130
 131         if (!dir)
 132                 return;
 133
 134         flags = BTRFS_I(dir)->flags;
 135
 136         if (flags & BTRFS_INODE_NOCOMPRESS) {
 137                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 138                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 139         } else if (flags & BTRFS_INODE_COMPRESS) {
 140                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 141                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 142         }
 143
 144         if (flags & BTRFS_INODE_NODATACOW) {
 145                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 146                 if (S_ISREG(inode->i_mode))
 147                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
 148         }
 149
 150         btrfs_update_iflags(inode);
 151 }
 152
 153 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 154 {
 155         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 156         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 157
 158         if (copy_to_user(arg, &flags, sizeof(flags)))
 159                 return -EFAULT;
 160         return 0;
 161 }
 162
 163 static int check_flags(unsigned int flags)
 164 {
 165         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 166                       FS_NOATIME_FL | FS_NODUMP_FL | \
 167                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 168                       FS_NOCOMP_FL | FS_COMPR_FL |
 169                       FS_NOCOW_FL))
 170                 return -EOPNOTSUPP;
 171
 172         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 173                 return -EINVAL;
 174
 175         return 0;
 176 }
 177
 178 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 179 {
 180         struct inode *inode = file_inode(file);
 181         struct btrfs_inode *ip = BTRFS_I(inode);
 182         struct btrfs_root *root = ip->root;
 183         struct btrfs_trans_handle *trans;
 184         unsigned int flags, oldflags;
 185         int ret;
 186         u64 ip_oldflags;
 187         unsigned int i_oldflags;
 188         umode_t mode;
 189
 190         if (btrfs_root_readonly(root))
 191                 return -EROFS;
 192
 193         if (copy_from_user(&flags, arg, sizeof(flags)))
 194                 return -EFAULT;
 195
 196         ret = check_flags(flags);
 197         if (ret)
 198                 return ret;
 199
 200         if (!inode_owner_or_capable(inode))
 201                 return -EACCES;
 202
 203         ret = mnt_want_write_file(file);
 204         if (ret)
 205                 return ret;
 206
 207         mutex_lock(&inode->i_mutex);
 208
 209         ip_oldflags = ip->flags;
 210         i_oldflags = inode->i_flags;
 211         mode = inode->i_mode;
 212
 213         flags = btrfs_mask_flags(inode->i_mode, flags);
 214         oldflags = btrfs_flags_to_ioctl(ip->flags);
 215         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 216                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 217                         ret = -EPERM;
 218                         goto out_unlock;
 219                 }
 220         }
 221
 222         if (flags & FS_SYNC_FL)
 223                 ip->flags |= BTRFS_INODE_SYNC;
 224         else
 225                 ip->flags &= ~BTRFS_INODE_SYNC;
 226         if (flags & FS_IMMUTABLE_FL)
 227                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 228         else
 229                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 230         if (flags & FS_APPEND_FL)
 231                 ip->flags |= BTRFS_INODE_APPEND;
 232         else
 233                 ip->flags &= ~BTRFS_INODE_APPEND;
 234         if (flags & FS_NODUMP_FL)
 235                 ip->flags |= BTRFS_INODE_NODUMP;
 236         else
 237                 ip->flags &= ~BTRFS_INODE_NODUMP;
 238         if (flags & FS_NOATIME_FL)
 239                 ip->flags |= BTRFS_INODE_NOATIME;
 240         else
 241                 ip->flags &= ~BTRFS_INODE_NOATIME;
 242         if (flags & FS_DIRSYNC_FL)
 243                 ip->flags |= BTRFS_INODE_DIRSYNC;
 244         else
 245                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 246         if (flags & FS_NOCOW_FL) {
 247                 if (S_ISREG(mode)) {
 248                         /*
 249                          * It's safe to turn csums off here, no extents exist.
 250                          * Otherwise we want the flag to reflect the real COW
 251                          * status of the file and will not set it.
 252                          */
 253                         if (inode->i_size == 0)
 254                                 ip->flags |= BTRFS_INODE_NODATACOW
 255                                            | BTRFS_INODE_NODATASUM;
 256                 } else {
 257                         ip->flags |= BTRFS_INODE_NODATACOW;
 258                 }
 259         } else {
 260                 /*
 261                  * Revert back under same assuptions as above
 262                  */
 263                 if (S_ISREG(mode)) {
 264                         if (inode->i_size == 0)
 265                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 266                                              | BTRFS_INODE_NODATASUM);
 267                 } else {
 268                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 269                 }
 270         }
 271
 272         /*
 273          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 274          * flag may be changed automatically if compression code won't make
 275          * things smaller.
 276          */
 277         if (flags & FS_NOCOMP_FL) {
 278                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 279                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 280         } else if (flags & FS_COMPR_FL) {
 281                 ip->flags |= BTRFS_INODE_COMPRESS;
 282                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 283         } else {
 284                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 285         }
 286
 287         trans = btrfs_start_transaction(root, 1);
 288         if (IS_ERR(trans)) {
 289                 ret = PTR_ERR(trans);
 290                 goto out_drop;
 291         }
 292
 293         btrfs_update_iflags(inode);
 294         inode_inc_iversion(inode);
 295         inode->i_ctime = CURRENT_TIME;
 296         ret = btrfs_update_inode(trans, root, inode);
 297
 298         btrfs_end_transaction(trans, root);
 299  out_drop:
 300         if (ret) {
 301                 ip->flags = ip_oldflags;
 302                 inode->i_flags = i_oldflags;
 303         }
 304
 305  out_unlock:
 306         mutex_unlock(&inode->i_mutex);
 307         mnt_drop_write_file(file);
 308         return ret;
 309 }
 310
 311 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 312 {
 313         struct inode *inode = file_inode(file);
 314
 315         return put_user(inode->i_generation, arg);
 316 }
 317
 318 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 319 {
 320         struct btrfs_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
 321         struct btrfs_device *device;
 322         struct request_queue *q;
 323         struct fstrim_range range;
 324         u64 minlen = ULLONG_MAX;
 325         u64 num_devices = 0;
 326         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 327         int ret;
 328
 329         if (!capable(CAP_SYS_ADMIN))
 330                 return -EPERM;
 331
 332         rcu_read_lock();
 333         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 334                                 dev_list) {
 335                 if (!device->bdev)
 336                         continue;
 337                 q = bdev_get_queue(device->bdev);
 338                 if (blk_queue_discard(q)) {
 339                         num_devices++;
 340                         minlen = min((u64)q->limits.discard_granularity,
 341                                      minlen);
 342                 }
 343         }
 344         rcu_read_unlock();
 345
 346         if (!num_devices)
 347                 return -EOPNOTSUPP;
 348         if (copy_from_user(&range, arg, sizeof(range)))
 349                 return -EFAULT;
 350         if (range.start > total_bytes ||
 351             range.len < fs_info->sb->s_blocksize)
 352                 return -EINVAL;
 353
 354         range.len = min(range.len, total_bytes - range.start);
 355         range.minlen = max(range.minlen, minlen);
 356         ret = btrfs_trim_fs(fs_info->tree_root, &range);
 357         if (ret < 0)
 358                 return ret;
 359
 360         if (copy_to_user(arg, &range, sizeof(range)))
 361                 return -EFAULT;
 362
 363         return 0;
 364 }
 365
 366 static noinline int create_subvol(struct inode *dir,
 367                                   struct dentry *dentry,
 368                                   char *name, int namelen,
 369                                   u64 *async_transid,
 370                                   struct btrfs_qgroup_inherit *inherit)
 371 {
 372         struct btrfs_trans_handle *trans;
 373         struct btrfs_key key;
 374         struct btrfs_root_item root_item;
 375         struct btrfs_inode_item *inode_item;
 376         struct extent_buffer *leaf;
 377         struct btrfs_root *root = BTRFS_I(dir)->root;
 378         struct btrfs_root *new_root;
 379         struct btrfs_block_rsv block_rsv;
 380         struct timespec cur_time = CURRENT_TIME;
 381         int ret;
 382         int err;
 383         u64 objectid;
 384         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 385         u64 index = 0;
 386         u64 qgroup_reserved;
 387         uuid_le new_uuid;
 388
 389         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 390         if (ret)
 391                 return ret;
 392
 393         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 394         /*
 395          * The same as the snapshot creation, please see the comment
 396          * of create_snapshot().
 397          */
 398         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 399                                                7, &qgroup_reserved);
 400         if (ret)
 401                 return ret;
 402
 403         trans = btrfs_start_transaction(root, 0);
 404         if (IS_ERR(trans)) {
 405                 ret = PTR_ERR(trans);
 406                 goto out;
 407         }
 408         trans->block_rsv = &block_rsv;
 409         trans->bytes_reserved = block_rsv.size;
 410
 411         ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
 412         if (ret)
 413                 goto fail;
 414
 415         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 416                                       0, objectid, NULL, 0, 0, 0);
 417         if (IS_ERR(leaf)) {
 418                 ret = PTR_ERR(leaf);
 419                 goto fail;
 420         }
 421
 422         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 423         btrfs_set_header_bytenr(leaf, leaf->start);
 424         btrfs_set_header_generation(leaf, trans->transid);
 425         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 426         btrfs_set_header_owner(leaf, objectid);
 427
 428         write_extent_buffer(leaf, root->fs_info->fsid,
 429                             (unsigned long)btrfs_header_fsid(leaf),
 430                             BTRFS_FSID_SIZE);
 431         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 432                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 433                             BTRFS_UUID_SIZE);
 434         btrfs_mark_buffer_dirty(leaf);
 435
 436         memset(&root_item, 0, sizeof(root_item));
 437
 438         inode_item = &root_item.inode;
 439         inode_item->generation = cpu_to_le64(1);
 440         inode_item->size = cpu_to_le64(3);
 441         inode_item->nlink = cpu_to_le32(1);
 442         inode_item->nbytes = cpu_to_le64(root->leafsize);
 443         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 444
 445         root_item.flags = 0;
 446         root_item.byte_limit = 0;
 447         inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
 448
 449         btrfs_set_root_bytenr(&root_item, leaf->start);
 450         btrfs_set_root_generation(&root_item, trans->transid);
 451         btrfs_set_root_level(&root_item, 0);
 452         btrfs_set_root_refs(&root_item, 1);
 453         btrfs_set_root_used(&root_item, leaf->len);
 454         btrfs_set_root_last_snapshot(&root_item, 0);
 455
 456         btrfs_set_root_generation_v2(&root_item,
 457                         btrfs_root_generation(&root_item));
 458         uuid_le_gen(&new_uuid);
 459         memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
 460         root_item.otime.sec = cpu_to_le64(cur_time.tv_sec);
 461         root_item.otime.nsec = cpu_to_le32(cur_time.tv_nsec);
 462         root_item.ctime = root_item.otime;
 463         btrfs_set_root_ctransid(&root_item, trans->transid);
 464         btrfs_set_root_otransid(&root_item, trans->transid);
 465
 466         btrfs_tree_unlock(leaf);
 467         free_extent_buffer(leaf);
 468         leaf = NULL;
 469
 470         btrfs_set_root_dirid(&root_item, new_dirid);
 471
 472         key.objectid = objectid;
 473         key.offset = 0;
 474         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 475         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 476                                 &root_item);
 477         if (ret)
 478                 goto fail;
 479
 480         key.offset = (u64)-1;
 481         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 482         if (IS_ERR(new_root)) {
 483                 btrfs_abort_transaction(trans, root, PTR_ERR(new_root));
 484                 ret = PTR_ERR(new_root);
 485                 goto fail;
 486         }
 487
 488         btrfs_record_root_in_trans(trans, new_root);
 489
 490         ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
 491         if (ret) {
 492                 /* We potentially lose an unused inode item here */
 493                 btrfs_abort_transaction(trans, root, ret);
 494                 goto fail;
 495         }
 496
 497         /*
 498          * insert the directory item
 499          */
 500         ret = btrfs_set_inode_index(dir, &index);
 501         if (ret) {
 502                 btrfs_abort_transaction(trans, root, ret);
 503                 goto fail;
 504         }
 505
 506         ret = btrfs_insert_dir_item(trans, root,
 507                                     name, namelen, dir, &key,
 508                                     BTRFS_FT_DIR, index);
 509         if (ret) {
 510                 btrfs_abort_transaction(trans, root, ret);
 511                 goto fail;
 512         }
 513
 514         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 515         ret = btrfs_update_inode(trans, root, dir);
 516         BUG_ON(ret);
 517
 518         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 519                                  objectid, root->root_key.objectid,
 520                                  btrfs_ino(dir), index, name, namelen);
 521
 522         BUG_ON(ret);
 523
 524 fail:
 525         trans->block_rsv = NULL;
 526         trans->bytes_reserved = 0;
 527         if (async_transid) {
 528                 *async_transid = trans->transid;
 529                 err = btrfs_commit_transaction_async(trans, root, 1);
 530                 if (err)
 531                         err = btrfs_commit_transaction(trans, root);
 532         } else {
 533                 err = btrfs_commit_transaction(trans, root);
 534         }
 535         if (err && !ret)
 536                 ret = err;
 537
 538         if (!ret)
 539                 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 540 out:
 541         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
 542         return ret;
 543 }
 544
 545 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 546                            struct dentry *dentry, char *name, int namelen,
 547                            u64 *async_transid, bool readonly,
 548                            struct btrfs_qgroup_inherit *inherit)
 549 {
 550         struct inode *inode;
 551         struct btrfs_pending_snapshot *pending_snapshot;
 552         struct btrfs_trans_handle *trans;
 553         int ret;
 554
 555         if (!root->ref_cows)
 556                 return -EINVAL;
 557
 558         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 559         if (!pending_snapshot)
 560                 return -ENOMEM;
 561
 562         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 563                              BTRFS_BLOCK_RSV_TEMP);
 564         /*
 565          * 1 - parent dir inode
 566          * 2 - dir entries
 567          * 1 - root item
 568          * 2 - root ref/backref
 569          * 1 - root of snapshot
 570          */
 571         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 572                                         &pending_snapshot->block_rsv, 7,
 573                                         &pending_snapshot->qgroup_reserved);
 574         if (ret)
 575                 goto out;
 576
 577         pending_snapshot->dentry = dentry;
 578         pending_snapshot->root = root;
 579         pending_snapshot->readonly = readonly;
 580         pending_snapshot->dir = dir;
 581         pending_snapshot->inherit = inherit;
 582
 583         trans = btrfs_start_transaction(root, 0);
 584         if (IS_ERR(trans)) {
 585                 ret = PTR_ERR(trans);
 586                 goto fail;
 587         }
 588
 589         spin_lock(&root->fs_info->trans_lock);
 590         list_add(&pending_snapshot->list,
 591                  &trans->transaction->pending_snapshots);
 592         spin_unlock(&root->fs_info->trans_lock);
 593         if (async_transid) {
 594                 *async_transid = trans->transid;
 595                 ret = btrfs_commit_transaction_async(trans,
 596                                      root->fs_info->extent_root, 1);
 597                 if (ret)
 598                         ret = btrfs_commit_transaction(trans, root);
 599         } else {
 600                 ret = btrfs_commit_transaction(trans,
 601                                                root->fs_info->extent_root);
 602         }
 603         if (ret)
 604                 goto fail;
 605
 606         ret = pending_snapshot->error;
 607         if (ret)
 608                 goto fail;
 609
 610         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 611         if (ret)
 612                 goto fail;
 613
 614         inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 615         if (IS_ERR(inode)) {
 616                 ret = PTR_ERR(inode);
 617                 goto fail;
 618         }
 619         BUG_ON(!inode);
 620         d_instantiate(dentry, inode);
 621         ret = 0;
 622 fail:
 623         btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,
 624                                          &pending_snapshot->block_rsv,
 625                                          pending_snapshot->qgroup_reserved);
 626 out:
 627         kfree(pending_snapshot);
 628         return ret;
 629 }
 630
 631 /*  copy of check_sticky in fs/namei.c()
 632 * It's inline, so penalty for filesystems that don't use sticky bit is
 633 * minimal.
 634 */
 635 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
 636 {
 637         kuid_t fsuid = current_fsuid();
 638
 639         if (!(dir->i_mode & S_ISVTX))
 640                 return 0;
 641         if (uid_eq(inode->i_uid, fsuid))
 642                 return 0;
 643         if (uid_eq(dir->i_uid, fsuid))
 644                 return 0;
 645         return !capable(CAP_FOWNER);
 646 }
 647
 648 /*  copy of may_delete in fs/namei.c()
 649  *      Check whether we can remove a link victim from directory dir, check
 650  *  whether the type of victim is right.
 651  *  1. We can't do it if dir is read-only (done in permission())
 652  *  2. We should have write and exec permissions on dir
 653  *  3. We can't remove anything from append-only dir
 654  *  4. We can't do anything with immutable dir (done in permission())
 655  *  5. If the sticky bit on dir is set we should either
 656  *      a. be owner of dir, or
 657  *      b. be owner of victim, or
 658  *      c. have CAP_FOWNER capability
 659  *  6. If the victim is append-only or immutable we can't do antyhing with
 660  *     links pointing to it.
 661  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 662  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 663  *  9. We can't remove a root or mountpoint.
 664  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 665  *     nfs_async_unlink().
 666  */
 667
 668 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
 669 {
 670         int error;
 671
 672         if (!victim->d_inode)
 673                 return -ENOENT;
 674
 675         BUG_ON(victim->d_parent->d_inode != dir);
 676         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 677
 678         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 679         if (error)
 680                 return error;
 681         if (IS_APPEND(dir))
 682                 return -EPERM;
 683         if (btrfs_check_sticky(dir, victim->d_inode)||
 684                 IS_APPEND(victim->d_inode)||
 685             IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
 686                 return -EPERM;
 687         if (isdir) {
 688                 if (!S_ISDIR(victim->d_inode->i_mode))
 689                         return -ENOTDIR;
 690                 if (IS_ROOT(victim))
 691                         return -EBUSY;
 692         } else if (S_ISDIR(victim->d_inode->i_mode))
 693                 return -EISDIR;
 694         if (IS_DEADDIR(dir))
 695                 return -ENOENT;
 696         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 697                 return -EBUSY;
 698         return 0;
 699 }
 700
 701 /* copy of may_create in fs/namei.c() */
 702 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 703 {
 704         if (child->d_inode)
 705                 return -EEXIST;
 706         if (IS_DEADDIR(dir))
 707                 return -ENOENT;
 708         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 709 }
 710
 711 /*
 712  * Create a new subvolume below @parent.  This is largely modeled after
 713  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 714  * inside this filesystem so it's quite a bit simpler.
 715  */
 716 static noinline int btrfs_mksubvol(struct path *parent,
 717                                    char *name, int namelen,
 718                                    struct btrfs_root *snap_src,
 719                                    u64 *async_transid, bool readonly,
 720                                    struct btrfs_qgroup_inherit *inherit)
 721 {
 722         struct inode *dir  = parent->dentry->d_inode;
 723         struct dentry *dentry;
 724         int error;
 725
 726         error = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
 727         if (error == -EINTR)
 728                 return error;
 729
 730         dentry = lookup_one_len(name, parent->dentry, namelen);
 731         error = PTR_ERR(dentry);
 732         if (IS_ERR(dentry))
 733                 goto out_unlock;
 734
 735         error = -EEXIST;
 736         if (dentry->d_inode)
 737                 goto out_dput;
 738
 739         error = btrfs_may_create(dir, dentry);
 740         if (error)
 741                 goto out_dput;
 742
 743         /*
 744          * even if this name doesn't exist, we may get hash collisions.
 745          * check for them now when we can safely fail
 746          */
 747         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 748                                                dir->i_ino, name,
 749                                                namelen);
 750         if (error)
 751                 goto out_dput;
 752
 753         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 754
 755         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 756                 goto out_up_read;
 757
 758         if (snap_src) {
 759                 error = create_snapshot(snap_src, dir, dentry, name, namelen,
 760                                         async_transid, readonly, inherit);
 761         } else {
 762                 error = create_subvol(dir, dentry, name, namelen,
 763                                       async_transid, inherit);
 764         }
 765         if (!error)
 766                 fsnotify_mkdir(dir, dentry);
 767 out_up_read:
 768         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 769 out_dput:
 770         dput(dentry);
 771 out_unlock:
 772         mutex_unlock(&dir->i_mutex);
 773         return error;
 774 }
 775
 776 /*
 777  * When we're defragging a range, we don't want to kick it off again
 778  * if it is really just waiting for delalloc to send it down.
 779  * If we find a nice big extent or delalloc range for the bytes in the
 780  * file you want to defrag, we return 0 to let you know to skip this
 781  * part of the file
 782  */
 783 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
 784 {
 785         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 786         struct extent_map *em = NULL;
 787         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 788         u64 end;
 789
 790         read_lock(&em_tree->lock);
 791         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 792         read_unlock(&em_tree->lock);
 793
 794         if (em) {
 795                 end = extent_map_end(em);
 796                 free_extent_map(em);
 797                 if (end - offset > thresh)
 798                         return 0;
 799         }
 800         /* if we already have a nice delalloc here, just stop */
 801         thresh /= 2;
 802         end = count_range_bits(io_tree, &offset, offset + thresh,
 803                                thresh, EXTENT_DELALLOC, 1);
 804         if (end >= thresh)
 805                 return 0;
 806         return 1;
 807 }
 808
 809 /*
 810  * helper function to walk through a file and find extents
 811  * newer than a specific transid, and smaller than thresh.
 812  *
 813  * This is used by the defragging code to find new and small
 814  * extents
 815  */
 816 static int find_new_extents(struct btrfs_root *root,
 817                             struct inode *inode, u64 newer_than,
 818                             u64 *off, int thresh)
 819 {
 820         struct btrfs_path *path;
 821         struct btrfs_key min_key;
 822         struct btrfs_key max_key;
 823         struct extent_buffer *leaf;
 824         struct btrfs_file_extent_item *extent;
 825         int type;
 826         int ret;
 827         u64 ino = btrfs_ino(inode);
 828
 829         path = btrfs_alloc_path();
 830         if (!path)
 831                 return -ENOMEM;
 832
 833         min_key.objectid = ino;
 834         min_key.type = BTRFS_EXTENT_DATA_KEY;
 835         min_key.offset = *off;
 836
 837         max_key.objectid = ino;
 838         max_key.type = (u8)-1;
 839         max_key.offset = (u64)-1;
 840
 841         path->keep_locks = 1;
 842
 843         while(1) {
 844                 ret = btrfs_search_forward(root, &min_key, &max_key,
 845                                            path, newer_than);
 846                 if (ret != 0)
 847                         goto none;
 848                 if (min_key.objectid != ino)
 849                         goto none;
 850                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 851                         goto none;
 852
 853                 leaf = path->nodes[0];
 854                 extent = btrfs_item_ptr(leaf, path->slots[0],
 855                                         struct btrfs_file_extent_item);
 856
 857                 type = btrfs_file_extent_type(leaf, extent);
 858                 if (type == BTRFS_FILE_EXTENT_REG &&
 859                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 860                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 861                         *off = min_key.offset;
 862                         btrfs_free_path(path);
 863                         return 0;
 864                 }
 865
 866                 if (min_key.offset == (u64)-1)
 867                         goto none;
 868
 869                 min_key.offset++;
 870                 btrfs_release_path(path);
 871         }
 872 none:
 873         btrfs_free_path(path);
 874         return -ENOENT;
 875 }
 876
 877 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 878 {
 879         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 880         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 881         struct extent_map *em;
 882         u64 len = PAGE_CACHE_SIZE;
 883
 884         /*
 885          * hopefully we have this extent in the tree already, try without
 886          * the full extent lock
 887          */
 888         read_lock(&em_tree->lock);
 889         em = lookup_extent_mapping(em_tree, start, len);
 890         read_unlock(&em_tree->lock);
 891
 892         if (!em) {
 893                 /* get the big lock and read metadata off disk */
 894                 lock_extent(io_tree, start, start + len - 1);
 895                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 896                 unlock_extent(io_tree, start, start + len - 1);
 897
 898                 if (IS_ERR(em))
 899                         return NULL;
 900         }
 901
 902         return em;
 903 }
 904
 905 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 906 {
 907         struct extent_map *next;
 908         bool ret = true;
 909
 910         /* this is the last extent */
 911         if (em->start + em->len >= i_size_read(inode))
 912                 return false;
 913
 914         next = defrag_lookup_extent(inode, em->start + em->len);
 915         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
 916                 ret = false;
 917
 918         free_extent_map(next);
 919         return ret;
 920 }
 921
 922 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
 923                                u64 *last_len, u64 *skip, u64 *defrag_end,
 924                                int compress)
 925 {
 926         struct extent_map *em;
 927         int ret = 1;
 928         bool next_mergeable = true;
 929
 930         /*
 931          * make sure that once we start defragging an extent, we keep on
 932          * defragging it
 933          */
 934         if (start < *defrag_end)
 935                 return 1;
 936
 937         *skip = 0;
 938
 939         em = defrag_lookup_extent(inode, start);
 940         if (!em)
 941                 return 0;
 942
 943         /* this will cover holes, and inline extents */
 944         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
 945                 ret = 0;
 946                 goto out;
 947         }
 948
 949         next_mergeable = defrag_check_next_extent(inode, em);
 950
 951         /*
 952          * we hit a real extent, if it is big or the next extent is not a
 953          * real extent, don't bother defragging it
 954          */
 955         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
 956             (em->len >= thresh || !next_mergeable))
 957                 ret = 0;
 958 out:
 959         /*
 960          * last_len ends up being a counter of how many bytes we've defragged.
 961          * every time we choose not to defrag an extent, we reset *last_len
 962          * so that the next tiny extent will force a defrag.
 963          *
 964          * The end result of this is that tiny extents before a single big
 965          * extent will force at least part of that big extent to be defragged.
 966          */
 967         if (ret) {
 968                 *defrag_end = extent_map_end(em);
 969         } else {
 970                 *last_len = 0;
 971                 *skip = extent_map_end(em);
 972                 *defrag_end = 0;
 973         }
 974
 975         free_extent_map(em);
 976         return ret;
 977 }
 978
 979 /*
 980  * it doesn't do much good to defrag one or two pages
 981  * at a time.  This pulls in a nice chunk of pages
 982  * to COW and defrag.
 983  *
 984  * It also makes sure the delalloc code has enough
 985  * dirty data to avoid making new small extents as part
 986  * of the defrag
 987  *
 988  * It's a good idea to start RA on this range
 989  * before calling this.
 990  */
 991 static int cluster_pages_for_defrag(struct inode *inode,
 992                                     struct page **pages,
 993                                     unsigned long start_index,
 994                                     int num_pages)
 995 {
 996         unsigned long file_end;
 997         u64 isize = i_size_read(inode);
 998         u64 page_start;
 999         u64 page_end;
1000         u64 page_cnt;
1001         int ret;
1002         int i;
1003         int i_done;
1004         struct btrfs_ordered_extent *ordered;
1005         struct extent_state *cached_state = NULL;
1006         struct extent_io_tree *tree;
1007         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1008
1009         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
1010         if (!isize || start_index > file_end)
1011                 return 0;
1012
1013         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1014
1015         ret = btrfs_delalloc_reserve_space(inode,
1016                                            page_cnt << PAGE_CACHE_SHIFT);
1017         if (ret)
1018                 return ret;
1019         i_done = 0;
1020         tree = &BTRFS_I(inode)->io_tree;
1021
1022         /* step one, lock all the pages */
1023         for (i = 0; i < page_cnt; i++) {
1024                 struct page *page;
1025 again:
1026                 page = find_or_create_page(inode->i_mapping,
1027                                            start_index + i, mask);
1028                 if (!page)
1029                         break;
1030
1031                 page_start = page_offset(page);
1032                 page_end = page_start + PAGE_CACHE_SIZE - 1;
1033                 while (1) {
1034                         lock_extent(tree, page_start, page_end);
1035                         ordered = btrfs_lookup_ordered_extent(inode,
1036                                                               page_start);
1037                         unlock_extent(tree, page_start, page_end);
1038                         if (!ordered)
1039                                 break;
1040
1041                         unlock_page(page);
1042                         btrfs_start_ordered_extent(inode, ordered, 1);
1043                         btrfs_put_ordered_extent(ordered);
1044                         lock_page(page);
1045                         /*
1046                          * we unlocked the page above, so we need check if
1047                          * it was released or not.
1048                          */
1049                         if (page->mapping != inode->i_mapping) {
1050                                 unlock_page(page);
1051                                 page_cache_release(page);
1052                                 goto again;
1053                         }
1054                 }
1055
1056                 if (!PageUptodate(page)) {
1057                         btrfs_readpage(NULL, page);
1058                         lock_page(page);
1059                         if (!PageUptodate(page)) {
1060                                 unlock_page(page);
1061                                 page_cache_release(page);
1062                                 ret = -EIO;
1063                                 break;
1064                         }
1065                 }
1066
1067                 if (page->mapping != inode->i_mapping) {
1068                         unlock_page(page);
1069                         page_cache_release(page);
1070                         goto again;
1071                 }
1072
1073                 pages[i] = page;
1074                 i_done++;
1075         }
1076         if (!i_done || ret)
1077                 goto out;
1078
1079         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1080                 goto out;
1081
1082         /*
1083          * so now we have a nice long stream of locked
1084          * and up to date pages, lets wait on them
1085          */
1086         for (i = 0; i < i_done; i++)
1087                 wait_on_page_writeback(pages[i]);
1088
1089         page_start = page_offset(pages[0]);
1090         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1091
1092         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1093                          page_start, page_end - 1, 0, &cached_state);
1094         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1095                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1096                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1097                           &cached_state, GFP_NOFS);
1098
1099         if (i_done != page_cnt) {
1100                 spin_lock(&BTRFS_I(inode)->lock);
1101                 BTRFS_I(inode)->outstanding_extents++;
1102                 spin_unlock(&BTRFS_I(inode)->lock);
1103                 btrfs_delalloc_release_space(inode,
1104                                      (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1105         }
1106
1107
1108         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1109                           &cached_state, GFP_NOFS);
1110
1111         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1112                              page_start, page_end - 1, &cached_state,
1113                              GFP_NOFS);
1114
1115         for (i = 0; i < i_done; i++) {
1116                 clear_page_dirty_for_io(pages[i]);
1117                 ClearPageChecked(pages[i]);
1118                 set_page_extent_mapped(pages[i]);
1119                 set_page_dirty(pages[i]);
1120                 unlock_page(pages[i]);
1121                 page_cache_release(pages[i]);
1122         }
1123         return i_done;
1124 out:
1125         for (i = 0; i < i_done; i++) {
1126                 unlock_page(pages[i]);
1127                 page_cache_release(pages[i]);
1128         }
1129         btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1130         return ret;
1131
1132 }
1133
1134 int btrfs_defrag_file(struct inode *inode, struct file *file,
1135                       struct btrfs_ioctl_defrag_range_args *range,
1136                       u64 newer_than, unsigned long max_to_defrag)
1137 {
1138         struct btrfs_root *root = BTRFS_I(inode)->root;
1139         struct file_ra_state *ra = NULL;
1140         unsigned long last_index;
1141         u64 isize = i_size_read(inode);
1142         u64 last_len = 0;
1143         u64 skip = 0;
1144         u64 defrag_end = 0;
1145         u64 newer_off = range->start;
1146         unsigned long i;
1147         unsigned long ra_index = 0;
1148         int ret;
1149         int defrag_count = 0;
1150         int compress_type = BTRFS_COMPRESS_ZLIB;
1151         int extent_thresh = range->extent_thresh;
1152         int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1153         int cluster = max_cluster;
1154         u64 new_align = ~((u64)128 * 1024 - 1);
1155         struct page **pages = NULL;
1156
1157         if (isize == 0)
1158                 return 0;
1159
1160         if (range->start >= isize)
1161                 return -EINVAL;
1162
1163         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1164                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1165                         return -EINVAL;
1166                 if (range->compress_type)
1167                         compress_type = range->compress_type;
1168         }
1169
1170         if (extent_thresh == 0)
1171                 extent_thresh = 256 * 1024;
1172
1173         /*
1174          * if we were not given a file, allocate a readahead
1175          * context
1176          */
1177         if (!file) {
1178                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1179                 if (!ra)
1180                         return -ENOMEM;
1181                 file_ra_state_init(ra, inode->i_mapping);
1182         } else {
1183                 ra = &file->f_ra;
1184         }
1185
1186         pages = kmalloc(sizeof(struct page *) * max_cluster,
1187                         GFP_NOFS);
1188         if (!pages) {
1189                 ret = -ENOMEM;
1190                 goto out_ra;
1191         }
1192
1193         /* find the last page to defrag */
1194         if (range->start + range->len > range->start) {
1195                 last_index = min_t(u64, isize - 1,
1196                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1197         } else {
1198                 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1199         }
1200
1201         if (newer_than) {
1202                 ret = find_new_extents(root, inode, newer_than,
1203                                        &newer_off, 64 * 1024);
1204                 if (!ret) {
1205                         range->start = newer_off;
1206                         /*
1207                          * we always align our defrag to help keep
1208                          * the extents in the file evenly spaced
1209                          */
1210                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1211                 } else
1212                         goto out_ra;
1213         } else {
1214                 i = range->start >> PAGE_CACHE_SHIFT;
1215         }
1216         if (!max_to_defrag)
1217                 max_to_defrag = last_index + 1;
1218
1219         /*
1220          * make writeback starts from i, so the defrag range can be
1221          * written sequentially.
1222          */
1223         if (i < inode->i_mapping->writeback_index)
1224                 inode->i_mapping->writeback_index = i;
1225
1226         while (i <= last_index && defrag_count < max_to_defrag &&
1227                (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1228                 PAGE_CACHE_SHIFT)) {
1229                 /*
1230                  * make sure we stop running if someone unmounts
1231                  * the FS
1232                  */
1233                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1234                         break;
1235
1236                 if (btrfs_defrag_cancelled(root->fs_info)) {
1237                         printk(KERN_DEBUG "btrfs: defrag_file cancelled\n");
1238                         ret = -EAGAIN;
1239                         break;
1240                 }
1241
1242                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1243                                          extent_thresh, &last_len, &skip,
1244                                          &defrag_end, range->flags &
1245                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1246                         unsigned long next;
1247                         /*
1248                          * the should_defrag function tells us how much to skip
1249                          * bump our counter by the suggested amount
1250                          */
1251                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1252                         i = max(i + 1, next);
1253                         continue;
1254                 }
1255
1256                 if (!newer_than) {
1257                         cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1258                                    PAGE_CACHE_SHIFT) - i;
1259                         cluster = min(cluster, max_cluster);
1260                 } else {
1261                         cluster = max_cluster;
1262                 }
1263
1264                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1265                         BTRFS_I(inode)->force_compress = compress_type;
1266
1267                 if (i + cluster > ra_index) {
1268                         ra_index = max(i, ra_index);
1269                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1270                                        cluster);
1271                         ra_index += max_cluster;
1272                 }
1273
1274                 mutex_lock(&inode->i_mutex);
1275                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1276                 if (ret < 0) {
1277                         mutex_unlock(&inode->i_mutex);
1278                         goto out_ra;
1279                 }
1280
1281                 defrag_count += ret;
1282                 balance_dirty_pages_ratelimited(inode->i_mapping);
1283                 mutex_unlock(&inode->i_mutex);
1284
1285                 if (newer_than) {
1286                         if (newer_off == (u64)-1)
1287                                 break;
1288
1289                         if (ret > 0)
1290                                 i += ret;
1291
1292                         newer_off = max(newer_off + 1,
1293                                         (u64)i << PAGE_CACHE_SHIFT);
1294
1295                         ret = find_new_extents(root, inode,
1296                                                newer_than, &newer_off,
1297                                                64 * 1024);
1298                         if (!ret) {
1299                                 range->start = newer_off;
1300                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1301                         } else {
1302                                 break;
1303                         }
1304                 } else {
1305                         if (ret > 0) {
1306                                 i += ret;
1307                                 last_len += ret << PAGE_CACHE_SHIFT;
1308                         } else {
1309                                 i++;
1310                                 last_len = 0;
1311                         }
1312                 }
1313         }
1314
1315         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1316                 filemap_flush(inode->i_mapping);
1317
1318         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1319                 /* the filemap_flush will queue IO into the worker threads, but
1320                  * we have to make sure the IO is actually started and that
1321                  * ordered extents get created before we return
1322                  */
1323                 atomic_inc(&root->fs_info->async_submit_draining);
1324                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1325                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1326                         wait_event(root->fs_info->async_submit_wait,
1327                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1328                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1329                 }
1330                 atomic_dec(&root->fs_info->async_submit_draining);
1331
1332                 mutex_lock(&inode->i_mutex);
1333                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1334                 mutex_unlock(&inode->i_mutex);
1335         }
1336
1337         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1338                 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1339         }
1340
1341         ret = defrag_count;
1342
1343 out_ra:
1344         if (!file)
1345                 kfree(ra);
1346         kfree(pages);
1347         return ret;
1348 }
1349
1350 static noinline int btrfs_ioctl_resize(struct file *file,
1351                                         void __user *arg)
1352 {
1353         u64 new_size;
1354         u64 old_size;
1355         u64 devid = 1;
1356         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
1357         struct btrfs_ioctl_vol_args *vol_args;
1358         struct btrfs_trans_handle *trans;
1359         struct btrfs_device *device = NULL;
1360         char *sizestr;
1361         char *devstr = NULL;
1362         int ret = 0;
1363         int mod = 0;
1364
1365         if (!capable(CAP_SYS_ADMIN))
1366                 return -EPERM;
1367
1368         ret = mnt_want_write_file(file);
1369         if (ret)
1370                 return ret;
1371
1372         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1373                         1)) {
1374                 pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
1375                 mnt_drop_write_file(file);
1376                 return -EINVAL;
1377         }
1378
1379         mutex_lock(&root->fs_info->volume_mutex);
1380         vol_args = memdup_user(arg, sizeof(*vol_args));
1381         if (IS_ERR(vol_args)) {
1382                 ret = PTR_ERR(vol_args);
1383                 goto out;
1384         }
1385
1386         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1387
1388         sizestr = vol_args->name;
1389         devstr = strchr(sizestr, ':');
1390         if (devstr) {
1391                 char *end;
1392                 sizestr = devstr + 1;
1393                 *devstr = '\0';
1394                 devstr = vol_args->name;
1395                 devid = simple_strtoull(devstr, &end, 10);
1396                 if (!devid) {
1397                         ret = -EINVAL;
1398                         goto out_free;
1399                 }
1400                 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1401                        (unsigned long long)devid);
1402         }
1403
1404         device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1405         if (!device) {
1406                 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1407                        (unsigned long long)devid);
1408                 ret = -ENODEV;
1409                 goto out_free;
1410         }
1411
1412         if (!device->writeable) {
1413                 printk(KERN_INFO "btrfs: resizer unable to apply on "
1414                        "readonly device %llu\n",
1415                        (unsigned long long)devid);
1416                 ret = -EPERM;
1417                 goto out_free;
1418         }
1419
1420         if (!strcmp(sizestr, "max"))
1421                 new_size = device->bdev->bd_inode->i_size;
1422         else {
1423                 if (sizestr[0] == '-') {
1424                         mod = -1;
1425                         sizestr++;
1426                 } else if (sizestr[0] == '+') {
1427                         mod = 1;
1428                         sizestr++;
1429                 }
1430                 new_size = memparse(sizestr, NULL);
1431                 if (new_size == 0) {
1432                         ret = -EINVAL;
1433                         goto out_free;
1434                 }
1435         }
1436
1437         if (device->is_tgtdev_for_dev_replace) {
1438                 ret = -EPERM;
1439                 goto out_free;
1440         }
1441
1442         old_size = device->total_bytes;
1443
1444         if (mod < 0) {
1445                 if (new_size > old_size) {
1446                         ret = -EINVAL;
1447                         goto out_free;
1448                 }
1449                 new_size = old_size - new_size;
1450         } else if (mod > 0) {
1451                 new_size = old_size + new_size;
1452         }
1453
1454         if (new_size < 256 * 1024 * 1024) {
1455                 ret = -EINVAL;
1456                 goto out_free;
1457         }
1458         if (new_size > device->bdev->bd_inode->i_size) {
1459                 ret = -EFBIG;
1460                 goto out_free;
1461         }
1462
1463         do_div(new_size, root->sectorsize);
1464         new_size *= root->sectorsize;
1465
1466         printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
1467                       rcu_str_deref(device->name),
1468                       (unsigned long long)new_size);
1469
1470         if (new_size > old_size) {
1471                 trans = btrfs_start_transaction(root, 0);
1472                 if (IS_ERR(trans)) {
1473                         ret = PTR_ERR(trans);
1474                         goto out_free;
1475                 }
1476                 ret = btrfs_grow_device(trans, device, new_size);
1477                 btrfs_commit_transaction(trans, root);
1478         } else if (new_size < old_size) {
1479                 ret = btrfs_shrink_device(device, new_size);
1480         } /* equal, nothing need to do */
1481
1482 out_free:
1483         kfree(vol_args);
1484 out:
1485         mutex_unlock(&root->fs_info->volume_mutex);
1486         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1487         mnt_drop_write_file(file);
1488         return ret;
1489 }
1490
1491 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1492                                 char *name, unsigned long fd, int subvol,
1493                                 u64 *transid, bool readonly,
1494                                 struct btrfs_qgroup_inherit *inherit)
1495 {
1496         int namelen;
1497         int ret = 0;
1498
1499         ret = mnt_want_write_file(file);
1500         if (ret)
1501                 goto out;
1502
1503         namelen = strlen(name);
1504         if (strchr(name, '/')) {
1505                 ret = -EINVAL;
1506                 goto out_drop_write;
1507         }
1508
1509         if (name[0] == '.' &&
1510            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1511                 ret = -EEXIST;
1512                 goto out_drop_write;
1513         }
1514
1515         if (subvol) {
1516                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1517                                      NULL, transid, readonly, inherit);
1518         } else {
1519                 struct fd src = fdget(fd);
1520                 struct inode *src_inode;
1521                 if (!src.file) {
1522                         ret = -EINVAL;
1523                         goto out_drop_write;
1524                 }
1525
1526                 src_inode = file_inode(src.file);
1527                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1528                         printk(KERN_INFO "btrfs: Snapshot src from "
1529                                "another FS\n");
1530                         ret = -EINVAL;
1531                 } else {
1532                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1533                                              BTRFS_I(src_inode)->root,
1534                                              transid, readonly, inherit);
1535                 }
1536                 fdput(src);
1537         }
1538 out_drop_write:
1539         mnt_drop_write_file(file);
1540 out:
1541         return ret;
1542 }
1543
1544 static noinline int btrfs_ioctl_snap_create(struct file *file,
1545                                             void __user *arg, int subvol)
1546 {
1547         struct btrfs_ioctl_vol_args *vol_args;
1548         int ret;
1549
1550         vol_args = memdup_user(arg, sizeof(*vol_args));
1551         if (IS_ERR(vol_args))
1552                 return PTR_ERR(vol_args);
1553         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1554
1555         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1556                                               vol_args->fd, subvol,
1557                                               NULL, false, NULL);
1558
1559         kfree(vol_args);
1560         return ret;
1561 }
1562
1563 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1564                                                void __user *arg, int subvol)
1565 {
1566         struct btrfs_ioctl_vol_args_v2 *vol_args;
1567         int ret;
1568         u64 transid = 0;
1569         u64 *ptr = NULL;
1570         bool readonly = false;
1571         struct btrfs_qgroup_inherit *inherit = NULL;
1572
1573         vol_args = memdup_user(arg, sizeof(*vol_args));
1574         if (IS_ERR(vol_args))
1575                 return PTR_ERR(vol_args);
1576         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1577
1578         if (vol_args->flags &
1579             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1580               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1581                 ret = -EOPNOTSUPP;
1582                 goto out;
1583         }
1584
1585         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1586                 ptr = &transid;
1587         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1588                 readonly = true;
1589         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1590                 if (vol_args->size > PAGE_CACHE_SIZE) {
1591                         ret = -EINVAL;
1592                         goto out;
1593                 }
1594                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1595                 if (IS_ERR(inherit)) {
1596                         ret = PTR_ERR(inherit);
1597                         goto out;
1598                 }
1599         }
1600
1601         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1602                                               vol_args->fd, subvol, ptr,
1603                                               readonly, inherit);
1604
1605         if (ret == 0 && ptr &&
1606             copy_to_user(arg +
1607                          offsetof(struct btrfs_ioctl_vol_args_v2,
1608                                   transid), ptr, sizeof(*ptr)))
1609                 ret = -EFAULT;
1610 out:
1611         kfree(vol_args);
1612         kfree(inherit);
1613         return ret;
1614 }
1615
1616 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1617                                                 void __user *arg)
1618 {
1619         struct inode *inode = file_inode(file);
1620         struct btrfs_root *root = BTRFS_I(inode)->root;
1621         int ret = 0;
1622         u64 flags = 0;
1623
1624         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1625                 return -EINVAL;
1626
1627         down_read(&root->fs_info->subvol_sem);
1628         if (btrfs_root_readonly(root))
1629                 flags |= BTRFS_SUBVOL_RDONLY;
1630         up_read(&root->fs_info->subvol_sem);
1631
1632         if (copy_to_user(arg, &flags, sizeof(flags)))
1633                 ret = -EFAULT;
1634
1635         return ret;
1636 }
1637
1638 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1639                                               void __user *arg)
1640 {
1641         struct inode *inode = file_inode(file);
1642         struct btrfs_root *root = BTRFS_I(inode)->root;
1643         struct btrfs_trans_handle *trans;
1644         u64 root_flags;
1645         u64 flags;
1646         int ret = 0;
1647
1648         ret = mnt_want_write_file(file);
1649         if (ret)
1650                 goto out;
1651
1652         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1653                 ret = -EINVAL;
1654                 goto out_drop_write;
1655         }
1656
1657         if (copy_from_user(&flags, arg, sizeof(flags))) {
1658                 ret = -EFAULT;
1659                 goto out_drop_write;
1660         }
1661
1662         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1663                 ret = -EINVAL;
1664                 goto out_drop_write;
1665         }
1666
1667         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1668                 ret = -EOPNOTSUPP;
1669                 goto out_drop_write;
1670         }
1671
1672         if (!inode_owner_or_capable(inode)) {
1673                 ret = -EACCES;
1674                 goto out_drop_write;
1675         }
1676
1677         down_write(&root->fs_info->subvol_sem);
1678
1679         /* nothing to do */
1680         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1681                 goto out_drop_sem;
1682
1683         root_flags = btrfs_root_flags(&root->root_item);
1684         if (flags & BTRFS_SUBVOL_RDONLY)
1685                 btrfs_set_root_flags(&root->root_item,
1686                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1687         else
1688                 btrfs_set_root_flags(&root->root_item,
1689                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1690
1691         trans = btrfs_start_transaction(root, 1);
1692         if (IS_ERR(trans)) {
1693                 ret = PTR_ERR(trans);
1694                 goto out_reset;
1695         }
1696
1697         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1698                                 &root->root_key, &root->root_item);
1699
1700         btrfs_commit_transaction(trans, root);
1701 out_reset:
1702         if (ret)
1703                 btrfs_set_root_flags(&root->root_item, root_flags);
1704 out_drop_sem:
1705         up_write(&root->fs_info->subvol_sem);
1706 out_drop_write:
1707         mnt_drop_write_file(file);
1708 out:
1709         return ret;
1710 }
1711
1712 /*
1713  * helper to check if the subvolume references other subvolumes
1714  */
1715 static noinline int may_destroy_subvol(struct btrfs_root *root)
1716 {
1717         struct btrfs_path *path;
1718         struct btrfs_key key;
1719         int ret;
1720
1721         path = btrfs_alloc_path();
1722         if (!path)
1723                 return -ENOMEM;
1724
1725         key.objectid = root->root_key.objectid;
1726         key.type = BTRFS_ROOT_REF_KEY;
1727         key.offset = (u64)-1;
1728
1729         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1730                                 &key, path, 0, 0);
1731         if (ret < 0)
1732                 goto out;
1733         BUG_ON(ret == 0);
1734
1735         ret = 0;
1736         if (path->slots[0] > 0) {
1737                 path->slots[0]--;
1738                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1739                 if (key.objectid == root->root_key.objectid &&
1740                     key.type == BTRFS_ROOT_REF_KEY)
1741                         ret = -ENOTEMPTY;
1742         }
1743 out:
1744         btrfs_free_path(path);
1745         return ret;
1746 }
1747
1748 static noinline int key_in_sk(struct btrfs_key *key,
1749                               struct btrfs_ioctl_search_key *sk)
1750 {
1751         struct btrfs_key test;
1752         int ret;
1753
1754         test.objectid = sk->min_objectid;
1755         test.type = sk->min_type;
1756         test.offset = sk->min_offset;
1757
1758         ret = btrfs_comp_cpu_keys(key, &test);
1759         if (ret < 0)
1760                 return 0;
1761
1762         test.objectid = sk->max_objectid;
1763         test.type = sk->max_type;
1764         test.offset = sk->max_offset;
1765
1766         ret = btrfs_comp_cpu_keys(key, &test);
1767         if (ret > 0)
1768                 return 0;
1769         return 1;
1770 }
1771
1772 static noinline int copy_to_sk(struct btrfs_root *root,
1773                                struct btrfs_path *path,
1774                                struct btrfs_key *key,
1775                                struct btrfs_ioctl_search_key *sk,
1776                                char *buf,
1777                                unsigned long *sk_offset,
1778                                int *num_found)
1779 {
1780         u64 found_transid;
1781         struct extent_buffer *leaf;
1782         struct btrfs_ioctl_search_header sh;
1783         unsigned long item_off;
1784         unsigned long item_len;
1785         int nritems;
1786         int i;
1787         int slot;
1788         int ret = 0;
1789
1790         leaf = path->nodes[0];
1791         slot = path->slots[0];
1792         nritems = btrfs_header_nritems(leaf);
1793
1794         if (btrfs_header_generation(leaf) > sk->max_transid) {
1795                 i = nritems;
1796                 goto advance_key;
1797         }
1798         found_transid = btrfs_header_generation(leaf);
1799
1800         for (i = slot; i < nritems; i++) {
1801                 item_off = btrfs_item_ptr_offset(leaf, i);
1802                 item_len = btrfs_item_size_nr(leaf, i);
1803
1804                 btrfs_item_key_to_cpu(leaf, key, i);
1805                 if (!key_in_sk(key, sk))
1806                         continue;
1807
1808                 if (sizeof(sh) + item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1809                         item_len = 0;
1810
1811                 if (sizeof(sh) + item_len + *sk_offset >
1812                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1813                         ret = 1;
1814                         goto overflow;
1815                 }
1816
1817                 sh.objectid = key->objectid;
1818                 sh.offset = key->offset;
1819                 sh.type = key->type;
1820                 sh.len = item_len;
1821                 sh.transid = found_transid;
1822
1823                 /* copy search result header */
1824                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1825                 *sk_offset += sizeof(sh);
1826
1827                 if (item_len) {
1828                         char *p = buf + *sk_offset;
1829                         /* copy the item */
1830                         read_extent_buffer(leaf, p,
1831                                            item_off, item_len);
1832                         *sk_offset += item_len;
1833                 }
1834                 (*num_found)++;
1835
1836                 if (*num_found >= sk->nr_items)
1837                         break;
1838         }
1839 advance_key:
1840         ret = 0;
1841         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1842                 key->offset++;
1843         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1844                 key->offset = 0;
1845                 key->type++;
1846         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1847                 key->offset = 0;
1848                 key->type = 0;
1849                 key->objectid++;
1850         } else
1851                 ret = 1;
1852 overflow:
1853         return ret;
1854 }
1855
1856 static noinline int search_ioctl(struct inode *inode,
1857                                  struct btrfs_ioctl_search_args *args)
1858 {
1859         struct btrfs_root *root;
1860         struct btrfs_key key;
1861         struct btrfs_key max_key;
1862         struct btrfs_path *path;
1863         struct btrfs_ioctl_search_key *sk = &args->key;
1864         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1865         int ret;
1866         int num_found = 0;
1867         unsigned long sk_offset = 0;
1868
1869         path = btrfs_alloc_path();
1870         if (!path)
1871                 return -ENOMEM;
1872
1873         if (sk->tree_id == 0) {
1874                 /* search the root of the inode that was passed */
1875                 root = BTRFS_I(inode)->root;
1876         } else {
1877                 key.objectid = sk->tree_id;
1878                 key.type = BTRFS_ROOT_ITEM_KEY;
1879                 key.offset = (u64)-1;
1880                 root = btrfs_read_fs_root_no_name(info, &key);
1881                 if (IS_ERR(root)) {
1882                         printk(KERN_ERR "could not find root %llu\n",
1883                                sk->tree_id);
1884                         btrfs_free_path(path);
1885                         return -ENOENT;
1886                 }
1887         }
1888
1889         key.objectid = sk->min_objectid;
1890         key.type = sk->min_type;
1891         key.offset = sk->min_offset;
1892
1893         max_key.objectid = sk->max_objectid;
1894         max_key.type = sk->max_type;
1895         max_key.offset = sk->max_offset;
1896
1897         path->keep_locks = 1;
1898
1899         while(1) {
1900                 ret = btrfs_search_forward(root, &key, &max_key, path,
1901                                            sk->min_transid);
1902                 if (ret != 0) {
1903                         if (ret > 0)
1904                                 ret = 0;
1905                         goto err;
1906                 }
1907                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1908                                  &sk_offset, &num_found);
1909                 btrfs_release_path(path);
1910                 if (ret || num_found >= sk->nr_items)
1911                         break;
1912
1913         }
1914         ret = 0;
1915 err:
1916         sk->nr_items = num_found;
1917         btrfs_free_path(path);
1918         return ret;
1919 }
1920
1921 static noinline int btrfs_ioctl_tree_search(struct file *file,
1922                                            void __user *argp)
1923 {
1924          struct btrfs_ioctl_search_args *args;
1925          struct inode *inode;
1926          int ret;
1927
1928         if (!capable(CAP_SYS_ADMIN))
1929                 return -EPERM;
1930
1931         args = memdup_user(argp, sizeof(*args));
1932         if (IS_ERR(args))
1933                 return PTR_ERR(args);
1934
1935         inode = file_inode(file);
1936         ret = search_ioctl(inode, args);
1937         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1938                 ret = -EFAULT;
1939         kfree(args);
1940         return ret;
1941 }
1942
1943 /*
1944  * Search INODE_REFs to identify path name of 'dirid' directory
1945  * in a 'tree_id' tree. and sets path name to 'name'.
1946  */
1947 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1948                                 u64 tree_id, u64 dirid, char *name)
1949 {
1950         struct btrfs_root *root;
1951         struct btrfs_key key;
1952         char *ptr;
1953         int ret = -1;
1954         int slot;
1955         int len;
1956         int total_len = 0;
1957         struct btrfs_inode_ref *iref;
1958         struct extent_buffer *l;
1959         struct btrfs_path *path;
1960
1961         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1962                 name[0]='\0';
1963                 return 0;
1964         }
1965
1966         path = btrfs_alloc_path();
1967         if (!path)
1968                 return -ENOMEM;
1969
1970         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1971
1972         key.objectid = tree_id;
1973         key.type = BTRFS_ROOT_ITEM_KEY;
1974         key.offset = (u64)-1;
1975         root = btrfs_read_fs_root_no_name(info, &key);
1976         if (IS_ERR(root)) {
1977                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1978                 ret = -ENOENT;
1979                 goto out;
1980         }
1981
1982         key.objectid = dirid;
1983         key.type = BTRFS_INODE_REF_KEY;
1984         key.offset = (u64)-1;
1985
1986         while(1) {
1987                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1988                 if (ret < 0)
1989                         goto out;
1990
1991                 l = path->nodes[0];
1992                 slot = path->slots[0];
1993                 if (ret > 0 && slot > 0)
1994                         slot--;
1995                 btrfs_item_key_to_cpu(l, &key, slot);
1996
1997                 if (ret > 0 && (key.objectid != dirid ||
1998                                 key.type != BTRFS_INODE_REF_KEY)) {
1999                         ret = -ENOENT;
2000                         goto out;
2001                 }
2002
2003                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2004                 len = btrfs_inode_ref_name_len(l, iref);
2005                 ptr -= len + 1;
2006                 total_len += len + 1;
2007                 if (ptr < name)
2008                         goto out;
2009
2010                 *(ptr + len) = '/';
2011                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
2012
2013                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2014                         break;
2015
2016                 btrfs_release_path(path);
2017                 key.objectid = key.offset;
2018                 key.offset = (u64)-1;
2019                 dirid = key.objectid;
2020         }
2021         if (ptr < name)
2022                 goto out;
2023         memmove(name, ptr, total_len);
2024         name[total_len]='\0';
2025         ret = 0;
2026 out:
2027         btrfs_free_path(path);
2028         return ret;
2029 }
2030
2031 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2032                                            void __user *argp)
2033 {
2034          struct btrfs_ioctl_ino_lookup_args *args;
2035          struct inode *inode;
2036          int ret;
2037
2038         if (!capable(CAP_SYS_ADMIN))
2039                 return -EPERM;
2040
2041         args = memdup_user(argp, sizeof(*args));
2042         if (IS_ERR(args))
2043                 return PTR_ERR(args);
2044
2045         inode = file_inode(file);
2046
2047         if (args->treeid == 0)
2048                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2049
2050         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2051                                         args->treeid, args->objectid,
2052                                         args->name);
2053
2054         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2055                 ret = -EFAULT;
2056
2057         kfree(args);
2058         return ret;
2059 }
2060
2061 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2062                                              void __user *arg)
2063 {
2064         struct dentry *parent = fdentry(file);
2065         struct dentry *dentry;
2066         struct inode *dir = parent->d_inode;
2067         struct inode *inode;
2068         struct btrfs_root *root = BTRFS_I(dir)->root;
2069         struct btrfs_root *dest = NULL;
2070         struct btrfs_ioctl_vol_args *vol_args;
2071         struct btrfs_trans_handle *trans;
2072         struct btrfs_block_rsv block_rsv;
2073         u64 qgroup_reserved;
2074         int namelen;
2075         int ret;
2076         int err = 0;
2077
2078         vol_args = memdup_user(arg, sizeof(*vol_args));
2079         if (IS_ERR(vol_args))
2080                 return PTR_ERR(vol_args);
2081
2082         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2083         namelen = strlen(vol_args->name);
2084         if (strchr(vol_args->name, '/') ||
2085             strncmp(vol_args->name, "..", namelen) == 0) {
2086                 err = -EINVAL;
2087                 goto out;
2088         }
2089
2090         err = mnt_want_write_file(file);
2091         if (err)
2092                 goto out;
2093
2094         err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
2095         if (err == -EINTR)
2096                 goto out;
2097         dentry = lookup_one_len(vol_args->name, parent, namelen);
2098         if (IS_ERR(dentry)) {
2099                 err = PTR_ERR(dentry);
2100                 goto out_unlock_dir;
2101         }
2102
2103         if (!dentry->d_inode) {
2104                 err = -ENOENT;
2105                 goto out_dput;
2106         }
2107
2108         inode = dentry->d_inode;
2109         dest = BTRFS_I(inode)->root;
2110         if (!capable(CAP_SYS_ADMIN)){
2111                 /*
2112                  * Regular user.  Only allow this with a special mount
2113                  * option, when the user has write+exec access to the
2114                  * subvol root, and when rmdir(2) would have been
2115                  * allowed.
2116                  *
2117                  * Note that this is _not_ check that the subvol is
2118                  * empty or doesn't contain data that we wouldn't
2119                  * otherwise be able to delete.
2120                  *
2121                  * Users who want to delete empty subvols should try
2122                  * rmdir(2).
2123                  */
2124                 err = -EPERM;
2125                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2126                         goto out_dput;
2127
2128                 /*
2129                  * Do not allow deletion if the parent dir is the same
2130                  * as the dir to be deleted.  That means the ioctl
2131                  * must be called on the dentry referencing the root
2132                  * of the subvol, not a random directory contained
2133                  * within it.
2134                  */
2135                 err = -EINVAL;
2136                 if (root == dest)
2137                         goto out_dput;
2138
2139                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2140                 if (err)
2141                         goto out_dput;
2142         }
2143
2144         /* check if subvolume may be deleted by a user */
2145         err = btrfs_may_delete(dir, dentry, 1);
2146         if (err)
2147                 goto out_dput;
2148
2149         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2150                 err = -EINVAL;
2151                 goto out_dput;
2152         }
2153
2154         mutex_lock(&inode->i_mutex);
2155         err = d_invalidate(dentry);
2156         if (err)
2157                 goto out_unlock;
2158
2159         down_write(&root->fs_info->subvol_sem);
2160
2161         err = may_destroy_subvol(dest);
2162         if (err)
2163                 goto out_up_write;
2164
2165         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2166         /*
2167          * One for dir inode, two for dir entries, two for root
2168          * ref/backref.
2169          */
2170         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2171                                                5, &qgroup_reserved);
2172         if (err)
2173                 goto out_up_write;
2174
2175         trans = btrfs_start_transaction(root, 0);
2176         if (IS_ERR(trans)) {
2177                 err = PTR_ERR(trans);
2178                 goto out_release;
2179         }
2180         trans->block_rsv = &block_rsv;
2181         trans->bytes_reserved = block_rsv.size;
2182
2183         ret = btrfs_unlink_subvol(trans, root, dir,
2184                                 dest->root_key.objectid,
2185                                 dentry->d_name.name,
2186                                 dentry->d_name.len);
2187         if (ret) {
2188                 err = ret;
2189                 btrfs_abort_transaction(trans, root, ret);
2190                 goto out_end_trans;
2191         }
2192
2193         btrfs_record_root_in_trans(trans, dest);
2194
2195         memset(&dest->root_item.drop_progress, 0,
2196                 sizeof(dest->root_item.drop_progress));
2197         dest->root_item.drop_level = 0;
2198         btrfs_set_root_refs(&dest->root_item, 0);
2199
2200         if (!xchg(&dest->orphan_item_inserted, 1)) {
2201                 ret = btrfs_insert_orphan_item(trans,
2202                                         root->fs_info->tree_root,
2203                                         dest->root_key.objectid);
2204                 if (ret) {
2205                         btrfs_abort_transaction(trans, root, ret);
2206                         err = ret;
2207                         goto out_end_trans;
2208                 }
2209         }
2210 out_end_trans:
2211         trans->block_rsv = NULL;
2212         trans->bytes_reserved = 0;
2213         ret = btrfs_end_transaction(trans, root);
2214         if (ret && !err)
2215                 err = ret;
2216         inode->i_flags |= S_DEAD;
2217 out_release:
2218         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
2219 out_up_write:
2220         up_write(&root->fs_info->subvol_sem);
2221 out_unlock:
2222         mutex_unlock(&inode->i_mutex);
2223         if (!err) {
2224                 shrink_dcache_sb(root->fs_info->sb);
2225                 btrfs_invalidate_inodes(dest);
2226                 d_delete(dentry);
2227
2228                 /* the last ref */
2229                 if (dest->cache_inode) {
2230                         iput(dest->cache_inode);
2231                         dest->cache_inode = NULL;
2232                 }
2233         }
2234 out_dput:
2235         dput(dentry);
2236 out_unlock_dir:
2237         mutex_unlock(&dir->i_mutex);
2238         mnt_drop_write_file(file);
2239 out:
2240         kfree(vol_args);
2241         return err;
2242 }
2243
2244 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2245 {
2246         struct inode *inode = file_inode(file);
2247         struct btrfs_root *root = BTRFS_I(inode)->root;
2248         struct btrfs_ioctl_defrag_range_args *range;
2249         int ret;
2250
2251         ret = mnt_want_write_file(file);
2252         if (ret)
2253                 return ret;
2254
2255         if (btrfs_root_readonly(root)) {
2256                 ret = -EROFS;
2257                 goto out;
2258         }
2259
2260         switch (inode->i_mode & S_IFMT) {
2261         case S_IFDIR:
2262                 if (!capable(CAP_SYS_ADMIN)) {
2263                         ret = -EPERM;
2264                         goto out;
2265                 }
2266                 ret = btrfs_defrag_root(root);
2267                 if (ret)
2268                         goto out;
2269                 ret = btrfs_defrag_root(root->fs_info->extent_root);
2270                 break;
2271         case S_IFREG:
2272                 if (!(file->f_mode & FMODE_WRITE)) {
2273                         ret = -EINVAL;
2274                         goto out;
2275                 }
2276
2277                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2278                 if (!range) {
2279                         ret = -ENOMEM;
2280                         goto out;
2281                 }
2282
2283                 if (argp) {
2284                         if (copy_from_user(range, argp,
2285                                            sizeof(*range))) {
2286                                 ret = -EFAULT;
2287                                 kfree(range);
2288                                 goto out;
2289                         }
2290                         /* compression requires us to start the IO */
2291                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2292                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2293                                 range->extent_thresh = (u32)-1;
2294                         }
2295                 } else {
2296                         /* the rest are all set to zero by kzalloc */
2297                         range->len = (u64)-1;
2298                 }
2299                 ret = btrfs_defrag_file(file_inode(file), file,
2300                                         range, 0, 0);
2301                 if (ret > 0)
2302                         ret = 0;
2303                 kfree(range);
2304                 break;
2305         default:
2306                 ret = -EINVAL;
2307         }
2308 out:
2309         mnt_drop_write_file(file);
2310         return ret;
2311 }
2312
2313 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2314 {
2315         struct btrfs_ioctl_vol_args *vol_args;
2316         int ret;
2317
2318         if (!capable(CAP_SYS_ADMIN))
2319                 return -EPERM;
2320
2321         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2322                         1)) {
2323                 pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2324                 return -EINVAL;
2325         }
2326
2327         mutex_lock(&root->fs_info->volume_mutex);
2328         vol_args = memdup_user(arg, sizeof(*vol_args));
2329         if (IS_ERR(vol_args)) {
2330                 ret = PTR_ERR(vol_args);
2331                 goto out;
2332         }
2333
2334         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2335         ret = btrfs_init_new_device(root, vol_args->name);
2336
2337         kfree(vol_args);
2338 out:
2339         mutex_unlock(&root->fs_info->volume_mutex);
2340         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2341         return ret;
2342 }
2343
2344 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2345 {
2346         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
2347         struct btrfs_ioctl_vol_args *vol_args;
2348         int ret;
2349
2350         if (!capable(CAP_SYS_ADMIN))
2351                 return -EPERM;
2352
2353         ret = mnt_want_write_file(file);
2354         if (ret)
2355                 return ret;
2356
2357         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2358                         1)) {
2359                 pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2360                 mnt_drop_write_file(file);
2361                 return -EINVAL;
2362         }
2363
2364         mutex_lock(&root->fs_info->volume_mutex);
2365         vol_args = memdup_user(arg, sizeof(*vol_args));
2366         if (IS_ERR(vol_args)) {
2367                 ret = PTR_ERR(vol_args);
2368                 goto out;
2369         }
2370
2371         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2372         ret = btrfs_rm_device(root, vol_args->name);
2373
2374         kfree(vol_args);
2375 out:
2376         mutex_unlock(&root->fs_info->volume_mutex);
2377         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2378         mnt_drop_write_file(file);
2379         return ret;
2380 }
2381
2382 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2383 {
2384         struct btrfs_ioctl_fs_info_args *fi_args;
2385         struct btrfs_device *device;
2386         struct btrfs_device *next;
2387         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2388         int ret = 0;
2389
2390         if (!capable(CAP_SYS_ADMIN))
2391                 return -EPERM;
2392
2393         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2394         if (!fi_args)
2395                 return -ENOMEM;
2396
2397         fi_args->num_devices = fs_devices->num_devices;
2398         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2399
2400         mutex_lock(&fs_devices->device_list_mutex);
2401         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2402                 if (device->devid > fi_args->max_id)
2403                         fi_args->max_id = device->devid;
2404         }
2405         mutex_unlock(&fs_devices->device_list_mutex);
2406
2407         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2408                 ret = -EFAULT;
2409
2410         kfree(fi_args);
2411         return ret;
2412 }
2413
2414 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2415 {
2416         struct btrfs_ioctl_dev_info_args *di_args;
2417         struct btrfs_device *dev;
2418         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2419         int ret = 0;
2420         char *s_uuid = NULL;
2421         char empty_uuid[BTRFS_UUID_SIZE] = {0};
2422
2423         if (!capable(CAP_SYS_ADMIN))
2424                 return -EPERM;
2425
2426         di_args = memdup_user(arg, sizeof(*di_args));
2427         if (IS_ERR(di_args))
2428                 return PTR_ERR(di_args);
2429
2430         if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2431                 s_uuid = di_args->uuid;
2432
2433         mutex_lock(&fs_devices->device_list_mutex);
2434         dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
2435
2436         if (!dev) {
2437                 ret = -ENODEV;
2438                 goto out;
2439         }
2440
2441         di_args->devid = dev->devid;
2442         di_args->bytes_used = dev->bytes_used;
2443         di_args->total_bytes = dev->total_bytes;
2444         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2445         if (dev->name) {
2446                 struct rcu_string *name;
2447
2448                 rcu_read_lock();
2449                 name = rcu_dereference(dev->name);
2450                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2451                 rcu_read_unlock();
2452                 di_args->path[sizeof(di_args->path) - 1] = 0;
2453         } else {
2454                 di_args->path[0] = '\0';
2455         }
2456
2457 out:
2458         mutex_unlock(&fs_devices->device_list_mutex);
2459         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2460                 ret = -EFAULT;
2461
2462         kfree(di_args);
2463         return ret;
2464 }
2465
2466 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2467                                        u64 off, u64 olen, u64 destoff)
2468 {
2469         struct inode *inode = file_inode(file);
2470         struct btrfs_root *root = BTRFS_I(inode)->root;
2471         struct fd src_file;
2472         struct inode *src;
2473         struct btrfs_trans_handle *trans;
2474         struct btrfs_path *path;
2475         struct extent_buffer *leaf;
2476         char *buf;
2477         struct btrfs_key key;
2478         u32 nritems;
2479         int slot;
2480         int ret;
2481         u64 len = olen;
2482         u64 bs = root->fs_info->sb->s_blocksize;
2483
2484         /*
2485          * TODO:
2486          * - split compressed inline extents.  annoying: we need to
2487          *   decompress into destination's address_space (the file offset
2488          *   may change, so source mapping won't do), then recompress (or
2489          *   otherwise reinsert) a subrange.
2490          * - allow ranges within the same file to be cloned (provided
2491          *   they don't overlap)?
2492          */
2493
2494         /* the destination must be opened for writing */
2495         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2496                 return -EINVAL;
2497
2498         if (btrfs_root_readonly(root))
2499                 return -EROFS;
2500
2501         ret = mnt_want_write_file(file);
2502         if (ret)
2503                 return ret;
2504
2505         src_file = fdget(srcfd);
2506         if (!src_file.file) {
2507                 ret = -EBADF;
2508                 goto out_drop_write;
2509         }
2510
2511         ret = -EXDEV;
2512         if (src_file.file->f_path.mnt != file->f_path.mnt)
2513                 goto out_fput;
2514
2515         src = file_inode(src_file.file);
2516
2517         ret = -EINVAL;
2518         if (src == inode)
2519                 goto out_fput;
2520
2521         /* the src must be open for reading */
2522         if (!(src_file.file->f_mode & FMODE_READ))
2523                 goto out_fput;
2524
2525         /* don't make the dst file partly checksummed */
2526         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2527             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2528                 goto out_fput;
2529
2530         ret = -EISDIR;
2531         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2532                 goto out_fput;
2533
2534         ret = -EXDEV;
2535         if (src->i_sb != inode->i_sb)
2536                 goto out_fput;
2537
2538         ret = -ENOMEM;
2539         buf = vmalloc(btrfs_level_size(root, 0));
2540         if (!buf)
2541                 goto out_fput;
2542
2543         path = btrfs_alloc_path();
2544         if (!path) {
2545                 vfree(buf);
2546                 goto out_fput;
2547         }
2548         path->reada = 2;
2549
2550         if (inode < src) {
2551                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2552                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2553         } else {
2554                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2555                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2556         }
2557
2558         /* determine range to clone */
2559         ret = -EINVAL;
2560         if (off + len > src->i_size || off + len < off)
2561                 goto out_unlock;
2562         if (len == 0)
2563                 olen = len = src->i_size - off;
2564         /* if we extend to eof, continue to block boundary */
2565         if (off + len == src->i_size)
2566                 len = ALIGN(src->i_size, bs) - off;
2567
2568         /* verify the end result is block aligned */
2569         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2570             !IS_ALIGNED(destoff, bs))
2571                 goto out_unlock;
2572
2573         if (destoff > inode->i_size) {
2574                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2575                 if (ret)
2576                         goto out_unlock;
2577         }
2578
2579         /* truncate page cache pages from target inode range */
2580         truncate_inode_pages_range(&inode->i_data, destoff,
2581                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
2582
2583         /* do any pending delalloc/csum calc on src, one way or
2584            another, and lock file content */
2585         while (1) {
2586                 struct btrfs_ordered_extent *ordered;
2587                 lock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2588                 ordered = btrfs_lookup_first_ordered_extent(src, off + len - 1);
2589                 if (!ordered &&
2590                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off + len - 1,
2591                                     EXTENT_DELALLOC, 0, NULL))
2592                         break;
2593                 unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2594                 if (ordered)
2595                         btrfs_put_ordered_extent(ordered);
2596                 btrfs_wait_ordered_range(src, off, len);
2597         }
2598
2599         /* clone data */
2600         key.objectid = btrfs_ino(src);
2601         key.type = BTRFS_EXTENT_DATA_KEY;
2602         key.offset = 0;
2603
2604         while (1) {
2605                 /*
2606                  * note the key will change type as we walk through the
2607                  * tree.
2608                  */
2609                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
2610                                 0, 0);
2611                 if (ret < 0)
2612                         goto out;
2613
2614                 nritems = btrfs_header_nritems(path->nodes[0]);
2615                 if (path->slots[0] >= nritems) {
2616                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
2617                         if (ret < 0)
2618                                 goto out;
2619                         if (ret > 0)
2620                                 break;
2621                         nritems = btrfs_header_nritems(path->nodes[0]);
2622                 }
2623                 leaf = path->nodes[0];
2624                 slot = path->slots[0];
2625
2626                 btrfs_item_key_to_cpu(leaf, &key, slot);
2627                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2628                     key.objectid != btrfs_ino(src))
2629                         break;
2630
2631                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2632                         struct btrfs_file_extent_item *extent;
2633                         int type;
2634                         u32 size;
2635                         struct btrfs_key new_key;
2636                         u64 disko = 0, diskl = 0;
2637                         u64 datao = 0, datal = 0;
2638                         u8 comp;
2639                         u64 endoff;
2640
2641                         size = btrfs_item_size_nr(leaf, slot);
2642                         read_extent_buffer(leaf, buf,
2643                                            btrfs_item_ptr_offset(leaf, slot),
2644                                            size);
2645
2646                         extent = btrfs_item_ptr(leaf, slot,
2647                                                 struct btrfs_file_extent_item);
2648                         comp = btrfs_file_extent_compression(leaf, extent);
2649                         type = btrfs_file_extent_type(leaf, extent);
2650                         if (type == BTRFS_FILE_EXTENT_REG ||
2651                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2652                                 disko = btrfs_file_extent_disk_bytenr(leaf,
2653                                                                       extent);
2654                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2655                                                                  extent);
2656                                 datao = btrfs_file_extent_offset(leaf, extent);
2657                                 datal = btrfs_file_extent_num_bytes(leaf,
2658                                                                     extent);
2659                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2660                                 /* take upper bound, may be compressed */
2661                                 datal = btrfs_file_extent_ram_bytes(leaf,
2662                                                                     extent);
2663                         }
2664                         btrfs_release_path(path);
2665
2666                         if (key.offset + datal <= off ||
2667                             key.offset >= off + len - 1)
2668                                 goto next;
2669
2670                         memcpy(&new_key, &key, sizeof(new_key));
2671                         new_key.objectid = btrfs_ino(inode);
2672                         if (off <= key.offset)
2673                                 new_key.offset = key.offset + destoff - off;
2674                         else
2675                                 new_key.offset = destoff;
2676
2677                         /*
2678                          * 1 - adjusting old extent (we may have to split it)
2679                          * 1 - add new extent
2680                          * 1 - inode update
2681                          */
2682                         trans = btrfs_start_transaction(root, 3);
2683                         if (IS_ERR(trans)) {
2684                                 ret = PTR_ERR(trans);
2685                                 goto out;
2686                         }
2687
2688                         if (type == BTRFS_FILE_EXTENT_REG ||
2689                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2690                                 /*
2691                                  *    a  | --- range to clone ---|  b
2692                                  * | ------------- extent ------------- |
2693                                  */
2694
2695                                 /* substract range b */
2696                                 if (key.offset + datal > off + len)
2697                                         datal = off + len - key.offset;
2698
2699                                 /* substract range a */
2700                                 if (off > key.offset) {
2701                                         datao += off - key.offset;
2702                                         datal -= off - key.offset;
2703                                 }
2704
2705                                 ret = btrfs_drop_extents(trans, root, inode,
2706                                                          new_key.offset,
2707                                                          new_key.offset + datal,
2708                                                          1);
2709                                 if (ret) {
2710                                         btrfs_abort_transaction(trans, root,
2711                                                                 ret);
2712                                         btrfs_end_transaction(trans, root);
2713                                         goto out;
2714                                 }
2715
2716                                 ret = btrfs_insert_empty_item(trans, root, path,
2717                                                               &new_key, size);
2718                                 if (ret) {
2719                                         btrfs_abort_transaction(trans, root,
2720                                                                 ret);
2721                                         btrfs_end_transaction(trans, root);
2722                                         goto out;
2723                                 }
2724
2725                                 leaf = path->nodes[0];
2726                                 slot = path->slots[0];
2727                                 write_extent_buffer(leaf, buf,
2728                                             btrfs_item_ptr_offset(leaf, slot),
2729                                             size);
2730
2731                                 extent = btrfs_item_ptr(leaf, slot,
2732                                                 struct btrfs_file_extent_item);
2733
2734                                 /* disko == 0 means it's a hole */
2735                                 if (!disko)
2736                                         datao = 0;
2737
2738                                 btrfs_set_file_extent_offset(leaf, extent,
2739                                                              datao);
2740                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2741                                                                 datal);
2742                                 if (disko) {
2743                                         inode_add_bytes(inode, datal);
2744                                         ret = btrfs_inc_extent_ref(trans, root,
2745                                                         disko, diskl, 0,
2746                                                         root->root_key.objectid,
2747                                                         btrfs_ino(inode),
2748                                                         new_key.offset - datao,
2749                                                         0);
2750                                         if (ret) {
2751                                                 btrfs_abort_transaction(trans,
2752                                                                         root,
2753                                                                         ret);
2754                                                 btrfs_end_transaction(trans,
2755                                                                       root);
2756                                                 goto out;
2757
2758                                         }
2759                                 }
2760                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2761                                 u64 skip = 0;
2762                                 u64 trim = 0;
2763                                 if (off > key.offset) {
2764                                         skip = off - key.offset;
2765                                         new_key.offset += skip;
2766                                 }
2767
2768                                 if (key.offset + datal > off + len)
2769                                         trim = key.offset + datal - (off + len);
2770
2771                                 if (comp && (skip || trim)) {
2772                                         ret = -EINVAL;
2773                                         btrfs_end_transaction(trans, root);
2774                                         goto out;
2775                                 }
2776                                 size -= skip + trim;
2777                                 datal -= skip + trim;
2778
2779                                 ret = btrfs_drop_extents(trans, root, inode,
2780                                                          new_key.offset,
2781                                                          new_key.offset + datal,
2782                                                          1);
2783                                 if (ret) {
2784                                         btrfs_abort_transaction(trans, root,
2785                                                                 ret);
2786                                         btrfs_end_transaction(trans, root);
2787                                         goto out;
2788                                 }
2789
2790                                 ret = btrfs_insert_empty_item(trans, root, path,
2791                                                               &new_key, size);
2792                                 if (ret) {
2793                                         btrfs_abort_transaction(trans, root,
2794                                                                 ret);
2795                                         btrfs_end_transaction(trans, root);
2796                                         goto out;
2797                                 }
2798
2799                                 if (skip) {
2800                                         u32 start =
2801                                           btrfs_file_extent_calc_inline_size(0);
2802                                         memmove(buf+start, buf+start+skip,
2803                                                 datal);
2804                                 }
2805
2806                                 leaf = path->nodes[0];
2807                                 slot = path->slots[0];
2808                                 write_extent_buffer(leaf, buf,
2809                                             btrfs_item_ptr_offset(leaf, slot),
2810                                             size);
2811                                 inode_add_bytes(inode, datal);
2812                         }
2813
2814                         btrfs_mark_buffer_dirty(leaf);
2815                         btrfs_release_path(path);
2816
2817                         inode_inc_iversion(inode);
2818                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2819
2820                         /*
2821                          * we round up to the block size at eof when
2822                          * determining which extents to clone above,
2823                          * but shouldn't round up the file size
2824                          */
2825                         endoff = new_key.offset + datal;
2826                         if (endoff > destoff+olen)
2827                                 endoff = destoff+olen;
2828                         if (endoff > inode->i_size)
2829                                 btrfs_i_size_write(inode, endoff);
2830
2831                         ret = btrfs_update_inode(trans, root, inode);
2832                         if (ret) {
2833                                 btrfs_abort_transaction(trans, root, ret);
2834                                 btrfs_end_transaction(trans, root);
2835                                 goto out;
2836                         }
2837                         ret = btrfs_end_transaction(trans, root);
2838                 }
2839 next:
2840                 btrfs_release_path(path);
2841                 key.offset++;
2842         }
2843         ret = 0;
2844 out:
2845         btrfs_release_path(path);
2846         unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2847 out_unlock:
2848         mutex_unlock(&src->i_mutex);
2849         mutex_unlock(&inode->i_mutex);
2850         vfree(buf);
2851         btrfs_free_path(path);
2852 out_fput:
2853         fdput(src_file);
2854 out_drop_write:
2855         mnt_drop_write_file(file);
2856         return ret;
2857 }
2858
2859 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2860 {
2861         struct btrfs_ioctl_clone_range_args args;
2862
2863         if (copy_from_user(&args, argp, sizeof(args)))
2864                 return -EFAULT;
2865         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2866                                  args.src_length, args.dest_offset);
2867 }
2868
2869 /*
2870  * there are many ways the trans_start and trans_end ioctls can lead
2871  * to deadlocks.  They should only be used by applications that
2872  * basically own the machine, and have a very in depth understanding
2873  * of all the possible deadlocks and enospc problems.
2874  */
2875 static long btrfs_ioctl_trans_start(struct file *file)
2876 {
2877         struct inode *inode = file_inode(file);
2878         struct btrfs_root *root = BTRFS_I(inode)->root;
2879         struct btrfs_trans_handle *trans;
2880         int ret;
2881
2882         ret = -EPERM;
2883         if (!capable(CAP_SYS_ADMIN))
2884                 goto out;
2885
2886         ret = -EINPROGRESS;
2887         if (file->private_data)
2888                 goto out;
2889
2890         ret = -EROFS;
2891         if (btrfs_root_readonly(root))
2892                 goto out;
2893
2894         ret = mnt_want_write_file(file);
2895         if (ret)
2896                 goto out;
2897
2898         atomic_inc(&root->fs_info->open_ioctl_trans);
2899
2900         ret = -ENOMEM;
2901         trans = btrfs_start_ioctl_transaction(root);
2902         if (IS_ERR(trans))
2903                 goto out_drop;
2904
2905         file->private_data = trans;
2906         return 0;
2907
2908 out_drop:
2909         atomic_dec(&root->fs_info->open_ioctl_trans);
2910         mnt_drop_write_file(file);
2911 out:
2912         return ret;
2913 }
2914
2915 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2916 {
2917         struct inode *inode = file_inode(file);
2918         struct btrfs_root *root = BTRFS_I(inode)->root;
2919         struct btrfs_root *new_root;
2920         struct btrfs_dir_item *di;
2921         struct btrfs_trans_handle *trans;
2922         struct btrfs_path *path;
2923         struct btrfs_key location;
2924         struct btrfs_disk_key disk_key;
2925         u64 objectid = 0;
2926         u64 dir_id;
2927         int ret;
2928
2929         if (!capable(CAP_SYS_ADMIN))
2930                 return -EPERM;
2931
2932         ret = mnt_want_write_file(file);
2933         if (ret)
2934                 return ret;
2935
2936         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
2937                 ret = -EFAULT;
2938                 goto out;
2939         }
2940
2941         if (!objectid)
2942                 objectid = root->root_key.objectid;
2943
2944         location.objectid = objectid;
2945         location.type = BTRFS_ROOT_ITEM_KEY;
2946         location.offset = (u64)-1;
2947
2948         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2949         if (IS_ERR(new_root)) {
2950                 ret = PTR_ERR(new_root);
2951                 goto out;
2952         }
2953
2954         if (btrfs_root_refs(&new_root->root_item) == 0) {
2955                 ret = -ENOENT;
2956                 goto out;
2957         }
2958
2959         path = btrfs_alloc_path();
2960         if (!path) {
2961                 ret = -ENOMEM;
2962                 goto out;
2963         }
2964         path->leave_spinning = 1;
2965
2966         trans = btrfs_start_transaction(root, 1);
2967         if (IS_ERR(trans)) {
2968                 btrfs_free_path(path);
2969                 ret = PTR_ERR(trans);
2970                 goto out;
2971         }
2972
2973         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2974         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2975                                    dir_id, "default", 7, 1);
2976         if (IS_ERR_OR_NULL(di)) {
2977                 btrfs_free_path(path);
2978                 btrfs_end_transaction(trans, root);
2979                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2980                        "this isn't going to work\n");
2981                 ret = -ENOENT;
2982                 goto out;
2983         }
2984
2985         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2986         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2987         btrfs_mark_buffer_dirty(path->nodes[0]);
2988         btrfs_free_path(path);
2989
2990         btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
2991         btrfs_end_transaction(trans, root);
2992 out:
2993         mnt_drop_write_file(file);
2994         return ret;
2995 }
2996
2997 void btrfs_get_block_group_info(struct list_head *groups_list,
2998                                 struct btrfs_ioctl_space_info *space)
2999 {
3000         struct btrfs_block_group_cache *block_group;
3001
3002         space->total_bytes = 0;
3003         space->used_bytes = 0;
3004         space->flags = 0;
3005         list_for_each_entry(block_group, groups_list, list) {
3006                 space->flags = block_group->flags;
3007                 space->total_bytes += block_group->key.offset;
3008                 space->used_bytes +=
3009                         btrfs_block_group_used(&block_group->item);
3010         }
3011 }
3012
3013 static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
3014 {
3015         struct btrfs_ioctl_space_args space_args;
3016         struct btrfs_ioctl_space_info space;
3017         struct btrfs_ioctl_space_info *dest;
3018         struct btrfs_ioctl_space_info *dest_orig;
3019         struct btrfs_ioctl_space_info __user *user_dest;
3020         struct btrfs_space_info *info;
3021         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
3022                        BTRFS_BLOCK_GROUP_SYSTEM,
3023                        BTRFS_BLOCK_GROUP_METADATA,
3024                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
3025         int num_types = 4;
3026         int alloc_size;
3027         int ret = 0;
3028         u64 slot_count = 0;
3029         int i, c;
3030
3031         if (copy_from_user(&space_args,
3032                            (struct btrfs_ioctl_space_args __user *)arg,
3033                            sizeof(space_args)))
3034                 return -EFAULT;
3035
3036         for (i = 0; i < num_types; i++) {
3037                 struct btrfs_space_info *tmp;
3038
3039                 info = NULL;
3040                 rcu_read_lock();
3041                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
3042                                         list) {
3043                         if (tmp->flags == types[i]) {
3044                                 info = tmp;
3045                                 break;
3046                         }
3047                 }
3048                 rcu_read_unlock();
3049
3050                 if (!info)
3051                         continue;
3052
3053                 down_read(&info->groups_sem);
3054                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3055                         if (!list_empty(&info->block_groups[c]))
3056                                 slot_count++;
3057                 }
3058                 up_read(&info->groups_sem);
3059         }
3060
3061         /* space_slots == 0 means they are asking for a count */
3062         if (space_args.space_slots == 0) {
3063                 space_args.total_spaces = slot_count;
3064                 goto out;
3065         }
3066
3067         slot_count = min_t(u64, space_args.space_slots, slot_count);
3068
3069         alloc_size = sizeof(*dest) * slot_count;
3070
3071         /* we generally have at most 6 or so space infos, one for each raid
3072          * level.  So, a whole page should be more than enough for everyone
3073          */
3074         if (alloc_size > PAGE_CACHE_SIZE)
3075                 return -ENOMEM;
3076
3077         space_args.total_spaces = 0;
3078         dest = kmalloc(alloc_size, GFP_NOFS);
3079         if (!dest)
3080                 return -ENOMEM;
3081         dest_orig = dest;
3082
3083         /* now we have a buffer to copy into */
3084         for (i = 0; i < num_types; i++) {
3085                 struct btrfs_space_info *tmp;
3086
3087                 if (!slot_count)
3088                         break;
3089
3090                 info = NULL;
3091                 rcu_read_lock();
3092                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
3093                                         list) {
3094                         if (tmp->flags == types[i]) {
3095                                 info = tmp;
3096                                 break;
3097                         }
3098                 }
3099                 rcu_read_unlock();
3100
3101                 if (!info)
3102                         continue;
3103                 down_read(&info->groups_sem);
3104                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3105                         if (!list_empty(&info->block_groups[c])) {
3106                                 btrfs_get_block_group_info(
3107                                         &info->block_groups[c], &space);
3108                                 memcpy(dest, &space, sizeof(space));
3109                                 dest++;
3110                                 space_args.total_spaces++;
3111                                 slot_count--;
3112                         }
3113                         if (!slot_count)
3114                                 break;
3115                 }
3116                 up_read(&info->groups_sem);
3117         }
3118
3119         user_dest = (struct btrfs_ioctl_space_info __user *)
3120                 (arg + sizeof(struct btrfs_ioctl_space_args));
3121
3122         if (copy_to_user(user_dest, dest_orig, alloc_size))
3123                 ret = -EFAULT;
3124
3125         kfree(dest_orig);
3126 out:
3127         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3128                 ret = -EFAULT;
3129
3130         return ret;
3131 }
3132
3133 /*
3134  * there are many ways the trans_start and trans_end ioctls can lead
3135  * to deadlocks.  They should only be used by applications that
3136  * basically own the machine, and have a very in depth understanding
3137  * of all the possible deadlocks and enospc problems.
3138  */
3139 long btrfs_ioctl_trans_end(struct file *file)
3140 {
3141         struct inode *inode = file_inode(file);
3142         struct btrfs_root *root = BTRFS_I(inode)->root;
3143         struct btrfs_trans_handle *trans;
3144
3145         trans = file->private_data;
3146         if (!trans)
3147                 return -EINVAL;
3148         file->private_data = NULL;
3149
3150         btrfs_end_transaction(trans, root);
3151
3152         atomic_dec(&root->fs_info->open_ioctl_trans);
3153
3154         mnt_drop_write_file(file);
3155         return 0;
3156 }
3157
3158 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3159                                             void __user *argp)
3160 {
3161         struct btrfs_trans_handle *trans;
3162         u64 transid;
3163         int ret;
3164
3165         trans = btrfs_attach_transaction_barrier(root);
3166         if (IS_ERR(trans)) {
3167                 if (PTR_ERR(trans) != -ENOENT)
3168                         return PTR_ERR(trans);
3169
3170                 /* No running transaction, don't bother */
3171                 transid = root->fs_info->last_trans_committed;
3172                 goto out;
3173         }
3174         transid = trans->transid;
3175         ret = btrfs_commit_transaction_async(trans, root, 0);
3176         if (ret) {
3177                 btrfs_end_transaction(trans, root);
3178                 return ret;
3179         }
3180 out:
3181         if (argp)
3182                 if (copy_to_user(argp, &transid, sizeof(transid)))
3183                         return -EFAULT;
3184         return 0;
3185 }
3186
3187 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
3188                                            void __user *argp)
3189 {
3190         u64 transid;
3191
3192         if (argp) {
3193                 if (copy_from_user(&transid, argp, sizeof(transid)))
3194                         return -EFAULT;
3195         } else {
3196                 transid = 0;  /* current trans */
3197         }
3198         return btrfs_wait_for_commit(root, transid);
3199 }
3200
3201 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3202 {
3203         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3204         struct btrfs_ioctl_scrub_args *sa;
3205         int ret;
3206
3207         if (!capable(CAP_SYS_ADMIN))
3208                 return -EPERM;
3209
3210         sa = memdup_user(arg, sizeof(*sa));
3211         if (IS_ERR(sa))
3212                 return PTR_ERR(sa);
3213
3214         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3215                 ret = mnt_want_write_file(file);
3216                 if (ret)
3217                         goto out;
3218         }
3219
3220         ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
3221                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3222                               0);
3223
3224         if (copy_to_user(arg, sa, sizeof(*sa)))
3225                 ret = -EFAULT;
3226
3227         if (!(sa->flags & BTRFS_SCRUB_READONLY))
3228                 mnt_drop_write_file(file);
3229 out:
3230         kfree(sa);
3231         return ret;
3232 }
3233
3234 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3235 {
3236         if (!capable(CAP_SYS_ADMIN))
3237                 return -EPERM;
3238
3239         return btrfs_scrub_cancel(root->fs_info);
3240 }
3241
3242 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3243                                        void __user *arg)
3244 {
3245         struct btrfs_ioctl_scrub_args *sa;
3246         int ret;
3247
3248         if (!capable(CAP_SYS_ADMIN))
3249                 return -EPERM;
3250
3251         sa = memdup_user(arg, sizeof(*sa));
3252         if (IS_ERR(sa))
3253                 return PTR_ERR(sa);
3254
3255         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3256
3257         if (copy_to_user(arg, sa, sizeof(*sa)))
3258                 ret = -EFAULT;
3259
3260         kfree(sa);
3261         return ret;
3262 }
3263
3264 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3265                                       void __user *arg)
3266 {
3267         struct btrfs_ioctl_get_dev_stats *sa;
3268         int ret;
3269
3270         sa = memdup_user(arg, sizeof(*sa));
3271         if (IS_ERR(sa))
3272                 return PTR_ERR(sa);
3273
3274         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3275                 kfree(sa);
3276                 return -EPERM;
3277         }
3278
3279         ret = btrfs_get_dev_stats(root, sa);
3280
3281         if (copy_to_user(arg, sa, sizeof(*sa)))
3282                 ret = -EFAULT;
3283
3284         kfree(sa);
3285         return ret;
3286 }
3287
3288 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
3289 {
3290         struct btrfs_ioctl_dev_replace_args *p;
3291         int ret;
3292
3293         if (!capable(CAP_SYS_ADMIN))
3294                 return -EPERM;
3295
3296         p = memdup_user(arg, sizeof(*p));
3297         if (IS_ERR(p))
3298                 return PTR_ERR(p);
3299
3300         switch (p->cmd) {
3301         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3302                 if (root->fs_info->sb->s_flags & MS_RDONLY)
3303                         return -EROFS;
3304
3305                 if (atomic_xchg(
3306                         &root->fs_info->mutually_exclusive_operation_running,
3307                         1)) {
3308                         pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
3309                         ret = -EINPROGRESS;
3310                 } else {
3311                         ret = btrfs_dev_replace_start(root, p);
3312                         atomic_set(
3313                          &root->fs_info->mutually_exclusive_operation_running,
3314                          0);
3315                 }
3316                 break;
3317         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3318                 btrfs_dev_replace_status(root->fs_info, p);
3319                 ret = 0;
3320                 break;
3321         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3322                 ret = btrfs_dev_replace_cancel(root->fs_info, p);
3323                 break;
3324         default:
3325                 ret = -EINVAL;
3326                 break;
3327         }
3328
3329         if (copy_to_user(arg, p, sizeof(*p)))
3330                 ret = -EFAULT;
3331
3332         kfree(p);
3333         return ret;
3334 }
3335
3336 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3337 {
3338         int ret = 0;
3339         int i;
3340         u64 rel_ptr;
3341         int size;
3342         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3343         struct inode_fs_paths *ipath = NULL;
3344         struct btrfs_path *path;
3345
3346         if (!capable(CAP_DAC_READ_SEARCH))
3347                 return -EPERM;
3348
3349         path = btrfs_alloc_path();
3350         if (!path) {
3351                 ret = -ENOMEM;
3352                 goto out;
3353         }
3354
3355         ipa = memdup_user(arg, sizeof(*ipa));
3356         if (IS_ERR(ipa)) {
3357                 ret = PTR_ERR(ipa);
3358                 ipa = NULL;
3359                 goto out;
3360         }
3361
3362         size = min_t(u32, ipa->size, 4096);
3363         ipath = init_ipath(size, root, path);
3364         if (IS_ERR(ipath)) {
3365                 ret = PTR_ERR(ipath);
3366                 ipath = NULL;
3367                 goto out;
3368         }
3369
3370         ret = paths_from_inode(ipa->inum, ipath);
3371         if (ret < 0)
3372                 goto out;
3373
3374         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3375                 rel_ptr = ipath->fspath->val[i] -
3376                           (u64)(unsigned long)ipath->fspath->val;
3377                 ipath->fspath->val[i] = rel_ptr;
3378         }
3379
3380         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
3381                            (void *)(unsigned long)ipath->fspath, size);
3382         if (ret) {
3383                 ret = -EFAULT;
3384                 goto out;
3385         }
3386
3387 out:
3388         btrfs_free_path(path);
3389         free_ipath(ipath);
3390         kfree(ipa);
3391
3392         return ret;
3393 }
3394
3395 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3396 {
3397         struct btrfs_data_container *inodes = ctx;
3398         const size_t c = 3 * sizeof(u64);
3399
3400         if (inodes->bytes_left >= c) {
3401                 inodes->bytes_left -= c;
3402                 inodes->val[inodes->elem_cnt] = inum;
3403                 inodes->val[inodes->elem_cnt + 1] = offset;
3404                 inodes->val[inodes->elem_cnt + 2] = root;
3405                 inodes->elem_cnt += 3;
3406         } else {
3407                 inodes->bytes_missing += c - inodes->bytes_left;
3408                 inodes->bytes_left = 0;
3409                 inodes->elem_missed += 3;
3410         }
3411
3412         return 0;
3413 }
3414
3415 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3416                                         void __user *arg)
3417 {
3418         int ret = 0;
3419         int size;
3420         struct btrfs_ioctl_logical_ino_args *loi;
3421         struct btrfs_data_container *inodes = NULL;
3422         struct btrfs_path *path = NULL;
3423
3424         if (!capable(CAP_SYS_ADMIN))
3425                 return -EPERM;
3426
3427         loi = memdup_user(arg, sizeof(*loi));
3428         if (IS_ERR(loi)) {
3429                 ret = PTR_ERR(loi);
3430                 loi = NULL;
3431                 goto out;
3432         }
3433
3434         path = btrfs_alloc_path();
3435         if (!path) {
3436                 ret = -ENOMEM;
3437                 goto out;
3438         }
3439
3440         size = min_t(u32, loi->size, 64 * 1024);
3441         inodes = init_data_container(size);
3442         if (IS_ERR(inodes)) {
3443                 ret = PTR_ERR(inodes);
3444                 inodes = NULL;
3445                 goto out;
3446         }
3447
3448         ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
3449                                           build_ino_list, inodes);
3450         if (ret == -EINVAL)
3451                 ret = -ENOENT;
3452         if (ret < 0)
3453                 goto out;
3454
3455         ret = copy_to_user((void *)(unsigned long)loi->inodes,
3456                            (void *)(unsigned long)inodes, size);
3457         if (ret)
3458                 ret = -EFAULT;
3459
3460 out:
3461         btrfs_free_path(path);
3462         vfree(inodes);
3463         kfree(loi);
3464
3465         return ret;
3466 }
3467
3468 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3469                                struct btrfs_ioctl_balance_args *bargs)
3470 {
3471         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3472
3473         bargs->flags = bctl->flags;
3474
3475         if (atomic_read(&fs_info->balance_running))
3476                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3477         if (atomic_read(&fs_info->balance_pause_req))
3478                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3479         if (atomic_read(&fs_info->balance_cancel_req))
3480                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3481
3482         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3483         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3484         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3485
3486         if (lock) {
3487                 spin_lock(&fs_info->balance_lock);
3488                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3489                 spin_unlock(&fs_info->balance_lock);
3490         } else {
3491                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3492         }
3493 }
3494
3495 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3496 {
3497         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3498         struct btrfs_fs_info *fs_info = root->fs_info;
3499         struct btrfs_ioctl_balance_args *bargs;
3500         struct btrfs_balance_control *bctl;
3501         bool need_unlock; /* for mut. excl. ops lock */
3502         int ret;
3503
3504         if (!capable(CAP_SYS_ADMIN))
3505                 return -EPERM;
3506
3507         ret = mnt_want_write_file(file);
3508         if (ret)
3509                 return ret;
3510
3511 again:
3512         if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
3513                 mutex_lock(&fs_info->volume_mutex);
3514                 mutex_lock(&fs_info->balance_mutex);
3515                 need_unlock = true;
3516                 goto locked;
3517         }
3518
3519         /*
3520          * mut. excl. ops lock is locked.  Three possibilites:
3521          *   (1) some other op is running
3522          *   (2) balance is running
3523          *   (3) balance is paused -- special case (think resume)
3524          */
3525         mutex_lock(&fs_info->balance_mutex);
3526         if (fs_info->balance_ctl) {
3527                 /* this is either (2) or (3) */
3528                 if (!atomic_read(&fs_info->balance_running)) {
3529                         mutex_unlock(&fs_info->balance_mutex);
3530                         if (!mutex_trylock(&fs_info->volume_mutex))
3531                                 goto again;
3532                         mutex_lock(&fs_info->balance_mutex);
3533
3534                         if (fs_info->balance_ctl &&
3535                             !atomic_read(&fs_info->balance_running)) {
3536                                 /* this is (3) */
3537                                 need_unlock = false;
3538                                 goto locked;
3539                         }
3540
3541                         mutex_unlock(&fs_info->balance_mutex);
3542                         mutex_unlock(&fs_info->volume_mutex);
3543                         goto again;
3544                 } else {
3545                         /* this is (2) */
3546                         mutex_unlock(&fs_info->balance_mutex);
3547                         ret = -EINPROGRESS;
3548                         goto out;
3549                 }
3550         } else {
3551                 /* this is (1) */
3552                 mutex_unlock(&fs_info->balance_mutex);
3553                 pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
3554                 ret = -EINVAL;
3555                 goto out;
3556         }
3557
3558 locked:
3559         BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
3560
3561         if (arg) {
3562                 bargs = memdup_user(arg, sizeof(*bargs));
3563                 if (IS_ERR(bargs)) {
3564                         ret = PTR_ERR(bargs);
3565                         goto out_unlock;
3566                 }
3567
3568                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
3569                         if (!fs_info->balance_ctl) {
3570                                 ret = -ENOTCONN;
3571                                 goto out_bargs;
3572                         }
3573
3574                         bctl = fs_info->balance_ctl;
3575                         spin_lock(&fs_info->balance_lock);
3576                         bctl->flags |= BTRFS_BALANCE_RESUME;
3577                         spin_unlock(&fs_info->balance_lock);
3578
3579                         goto do_balance;
3580                 }
3581         } else {
3582                 bargs = NULL;
3583         }
3584
3585         if (fs_info->balance_ctl) {
3586                 ret = -EINPROGRESS;
3587                 goto out_bargs;
3588         }
3589
3590         bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3591         if (!bctl) {
3592                 ret = -ENOMEM;
3593                 goto out_bargs;
3594         }
3595
3596         bctl->fs_info = fs_info;
3597         if (arg) {
3598                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3599                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3600                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3601
3602                 bctl->flags = bargs->flags;
3603         } else {
3604                 /* balance everything - no filters */
3605                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3606         }
3607
3608 do_balance:
3609         /*
3610          * Ownership of bctl and mutually_exclusive_operation_running
3611          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
3612          * or, if restriper was paused all the way until unmount, in
3613          * free_fs_info.  mutually_exclusive_operation_running is
3614          * cleared in __cancel_balance.
3615          */
3616         need_unlock = false;
3617
3618         ret = btrfs_balance(bctl, bargs);
3619
3620         if (arg) {
3621                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3622                         ret = -EFAULT;
3623         }
3624
3625 out_bargs:
3626         kfree(bargs);
3627 out_unlock:
3628         mutex_unlock(&fs_info->balance_mutex);
3629         mutex_unlock(&fs_info->volume_mutex);
3630         if (need_unlock)
3631                 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3632 out:
3633         mnt_drop_write_file(file);
3634         return ret;
3635 }
3636
3637 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
3638 {
3639         if (!capable(CAP_SYS_ADMIN))
3640                 return -EPERM;
3641
3642         switch (cmd) {
3643         case BTRFS_BALANCE_CTL_PAUSE:
3644                 return btrfs_pause_balance(root->fs_info);
3645         case BTRFS_BALANCE_CTL_CANCEL:
3646                 return btrfs_cancel_balance(root->fs_info);
3647         }
3648
3649         return -EINVAL;
3650 }
3651
3652 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
3653                                          void __user *arg)
3654 {
3655         struct btrfs_fs_info *fs_info = root->fs_info;
3656         struct btrfs_ioctl_balance_args *bargs;
3657         int ret = 0;
3658
3659         if (!capable(CAP_SYS_ADMIN))
3660                 return -EPERM;
3661
3662         mutex_lock(&fs_info->balance_mutex);
3663         if (!fs_info->balance_ctl) {
3664                 ret = -ENOTCONN;
3665                 goto out;
3666         }
3667
3668         bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
3669         if (!bargs) {
3670                 ret = -ENOMEM;
3671                 goto out;
3672         }
3673
3674         update_ioctl_balance_args(fs_info, 1, bargs);
3675
3676         if (copy_to_user(arg, bargs, sizeof(*bargs)))
3677                 ret = -EFAULT;
3678
3679         kfree(bargs);
3680 out:
3681         mutex_unlock(&fs_info->balance_mutex);
3682         return ret;
3683 }
3684
3685 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
3686 {
3687         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3688         struct btrfs_ioctl_quota_ctl_args *sa;
3689         struct btrfs_trans_handle *trans = NULL;
3690         int ret;
3691         int err;
3692
3693         if (!capable(CAP_SYS_ADMIN))
3694                 return -EPERM;
3695
3696         ret = mnt_want_write_file(file);
3697         if (ret)
3698                 return ret;
3699
3700         sa = memdup_user(arg, sizeof(*sa));
3701         if (IS_ERR(sa)) {
3702                 ret = PTR_ERR(sa);
3703                 goto drop_write;
3704         }
3705
3706         down_write(&root->fs_info->subvol_sem);
3707         trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
3708         if (IS_ERR(trans)) {
3709                 ret = PTR_ERR(trans);
3710                 goto out;
3711         }
3712
3713         switch (sa->cmd) {
3714         case BTRFS_QUOTA_CTL_ENABLE:
3715                 ret = btrfs_quota_enable(trans, root->fs_info);
3716                 break;
3717         case BTRFS_QUOTA_CTL_DISABLE:
3718                 ret = btrfs_quota_disable(trans, root->fs_info);
3719                 break;
3720         default:
3721                 ret = -EINVAL;
3722                 break;
3723         }
3724
3725         if (copy_to_user(arg, sa, sizeof(*sa)))
3726                 ret = -EFAULT;
3727
3728         err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
3729         if (err && !ret)
3730                 ret = err;
3731 out:
3732         kfree(sa);
3733         up_write(&root->fs_info->subvol_sem);
3734 drop_write:
3735         mnt_drop_write_file(file);
3736         return ret;
3737 }
3738
3739 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
3740 {
3741         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3742         struct btrfs_ioctl_qgroup_assign_args *sa;
3743         struct btrfs_trans_handle *trans;
3744         int ret;
3745         int err;
3746
3747         if (!capable(CAP_SYS_ADMIN))
3748                 return -EPERM;
3749
3750         ret = mnt_want_write_file(file);
3751         if (ret)
3752                 return ret;
3753
3754         sa = memdup_user(arg, sizeof(*sa));
3755         if (IS_ERR(sa)) {
3756                 ret = PTR_ERR(sa);
3757                 goto drop_write;
3758         }
3759
3760         trans = btrfs_join_transaction(root);
3761         if (IS_ERR(trans)) {
3762                 ret = PTR_ERR(trans);
3763                 goto out;
3764         }
3765
3766         /* FIXME: check if the IDs really exist */
3767         if (sa->assign) {
3768                 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
3769                                                 sa->src, sa->dst);
3770         } else {
3771                 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
3772                                                 sa->src, sa->dst);
3773         }
3774
3775         err = btrfs_end_transaction(trans, root);
3776         if (err && !ret)
3777                 ret = err;
3778
3779 out:
3780         kfree(sa);
3781 drop_write:
3782         mnt_drop_write_file(file);
3783         return ret;
3784 }
3785
3786 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
3787 {
3788         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3789         struct btrfs_ioctl_qgroup_create_args *sa;
3790         struct btrfs_trans_handle *trans;
3791         int ret;
3792         int err;
3793
3794         if (!capable(CAP_SYS_ADMIN))
3795                 return -EPERM;
3796
3797         ret = mnt_want_write_file(file);
3798         if (ret)
3799                 return ret;
3800
3801         sa = memdup_user(arg, sizeof(*sa));
3802         if (IS_ERR(sa)) {
3803                 ret = PTR_ERR(sa);
3804                 goto drop_write;
3805         }
3806
3807         if (!sa->qgroupid) {
3808                 ret = -EINVAL;
3809                 goto out;
3810         }
3811
3812         trans = btrfs_join_transaction(root);
3813         if (IS_ERR(trans)) {
3814                 ret = PTR_ERR(trans);
3815                 goto out;
3816         }
3817
3818         /* FIXME: check if the IDs really exist */
3819         if (sa->create) {
3820                 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
3821                                           NULL);
3822         } else {
3823                 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
3824         }
3825
3826         err = btrfs_end_transaction(trans, root);
3827         if (err && !ret)
3828                 ret = err;
3829
3830 out:
3831         kfree(sa);
3832 drop_write:
3833         mnt_drop_write_file(file);
3834         return ret;
3835 }
3836
3837 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
3838 {
3839         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3840         struct btrfs_ioctl_qgroup_limit_args *sa;
3841         struct btrfs_trans_handle *trans;
3842         int ret;
3843         int err;
3844         u64 qgroupid;
3845
3846         if (!capable(CAP_SYS_ADMIN))
3847                 return -EPERM;
3848
3849         ret = mnt_want_write_file(file);
3850         if (ret)
3851                 return ret;
3852
3853         sa = memdup_user(arg, sizeof(*sa));
3854         if (IS_ERR(sa)) {
3855                 ret = PTR_ERR(sa);
3856                 goto drop_write;
3857         }
3858
3859         trans = btrfs_join_transaction(root);
3860         if (IS_ERR(trans)) {
3861                 ret = PTR_ERR(trans);
3862                 goto out;
3863         }
3864
3865         qgroupid = sa->qgroupid;
3866         if (!qgroupid) {
3867                 /* take the current subvol as qgroup */
3868                 qgroupid = root->root_key.objectid;
3869         }
3870
3871         /* FIXME: check if the IDs really exist */
3872         ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
3873
3874         err = btrfs_end_transaction(trans, root);
3875         if (err && !ret)
3876                 ret = err;
3877
3878 out:
3879         kfree(sa);
3880 drop_write:
3881         mnt_drop_write_file(file);
3882         return ret;
3883 }
3884
3885 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
3886 {
3887         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3888         struct btrfs_ioctl_quota_rescan_args *qsa;
3889         int ret;
3890
3891         if (!capable(CAP_SYS_ADMIN))
3892                 return -EPERM;
3893
3894         ret = mnt_want_write_file(file);
3895         if (ret)
3896                 return ret;
3897
3898         qsa = memdup_user(arg, sizeof(*qsa));
3899         if (IS_ERR(qsa)) {
3900                 ret = PTR_ERR(qsa);
3901                 goto drop_write;
3902         }
3903
3904         if (qsa->flags) {
3905                 ret = -EINVAL;
3906                 goto out;
3907         }
3908
3909         ret = btrfs_qgroup_rescan(root->fs_info);
3910
3911 out:
3912         kfree(qsa);
3913 drop_write:
3914         mnt_drop_write_file(file);
3915         return ret;
3916 }
3917
3918 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
3919 {
3920         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3921         struct btrfs_ioctl_quota_rescan_args *qsa;
3922         int ret = 0;
3923
3924         if (!capable(CAP_SYS_ADMIN))
3925                 return -EPERM;
3926
3927         qsa = kzalloc(sizeof(*qsa), GFP_NOFS);
3928         if (!qsa)
3929                 return -ENOMEM;
3930
3931         if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3932                 qsa->flags = 1;
3933                 qsa->progress = root->fs_info->qgroup_rescan_progress.objectid;
3934         }
3935
3936         if (copy_to_user(arg, qsa, sizeof(*qsa)))
3937                 ret = -EFAULT;
3938
3939         kfree(qsa);
3940         return ret;
3941 }
3942
3943 static long btrfs_ioctl_set_received_subvol(struct file *file,
3944                                             void __user *arg)
3945 {
3946         struct btrfs_ioctl_received_subvol_args *sa = NULL;
3947         struct inode *inode = file_inode(file);
3948         struct btrfs_root *root = BTRFS_I(inode)->root;
3949         struct btrfs_root_item *root_item = &root->root_item;
3950         struct btrfs_trans_handle *trans;
3951         struct timespec ct = CURRENT_TIME;
3952         int ret = 0;
3953
3954         ret = mnt_want_write_file(file);
3955         if (ret < 0)
3956                 return ret;
3957
3958         down_write(&root->fs_info->subvol_sem);
3959
3960         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
3961                 ret = -EINVAL;
3962                 goto out;
3963         }
3964
3965         if (btrfs_root_readonly(root)) {
3966                 ret = -EROFS;
3967                 goto out;
3968         }
3969
3970         if (!inode_owner_or_capable(inode)) {
3971                 ret = -EACCES;
3972                 goto out;
3973         }
3974
3975         sa = memdup_user(arg, sizeof(*sa));
3976         if (IS_ERR(sa)) {
3977                 ret = PTR_ERR(sa);
3978                 sa = NULL;
3979                 goto out;
3980         }
3981
3982         trans = btrfs_start_transaction(root, 1);
3983         if (IS_ERR(trans)) {
3984                 ret = PTR_ERR(trans);
3985                 trans = NULL;
3986                 goto out;
3987         }
3988
3989         sa->rtransid = trans->transid;
3990         sa->rtime.sec = ct.tv_sec;
3991         sa->rtime.nsec = ct.tv_nsec;
3992
3993         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
3994         btrfs_set_root_stransid(root_item, sa->stransid);
3995         btrfs_set_root_rtransid(root_item, sa->rtransid);
3996         root_item->stime.sec = cpu_to_le64(sa->stime.sec);
3997         root_item->stime.nsec = cpu_to_le32(sa->stime.nsec);
3998         root_item->rtime.sec = cpu_to_le64(sa->rtime.sec);
3999         root_item->rtime.nsec = cpu_to_le32(sa->rtime.nsec);
4000
4001         ret = btrfs_update_root(trans, root->fs_info->tree_root,
4002                                 &root->root_key, &root->root_item);
4003         if (ret < 0) {
4004                 btrfs_end_transaction(trans, root);
4005                 trans = NULL;
4006                 goto out;
4007         } else {
4008                 ret = btrfs_commit_transaction(trans, root);
4009                 if (ret < 0)
4010                         goto out;
4011         }
4012
4013         ret = copy_to_user(arg, sa, sizeof(*sa));
4014         if (ret)
4015                 ret = -EFAULT;
4016
4017 out:
4018         kfree(sa);
4019         up_write(&root->fs_info->subvol_sem);
4020         mnt_drop_write_file(file);
4021         return ret;
4022 }
4023
4024 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
4025 {
4026         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
4027         const char *label = root->fs_info->super_copy->label;
4028         size_t len = strnlen(label, BTRFS_LABEL_SIZE);
4029         int ret;
4030
4031         if (len == BTRFS_LABEL_SIZE) {
4032                 pr_warn("btrfs: label is too long, return the first %zu bytes\n",
4033                         --len);
4034         }
4035
4036         mutex_lock(&root->fs_info->volume_mutex);
4037         ret = copy_to_user(arg, label, len);
4038         mutex_unlock(&root->fs_info->volume_mutex);
4039
4040         return ret ? -EFAULT : 0;
4041 }
4042
4043 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4044 {
4045         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
4046         struct btrfs_super_block *super_block = root->fs_info->super_copy;
4047         struct btrfs_trans_handle *trans;
4048         char label[BTRFS_LABEL_SIZE];
4049         int ret;
4050
4051         if (!capable(CAP_SYS_ADMIN))
4052                 return -EPERM;
4053
4054         if (copy_from_user(label, arg, sizeof(label)))
4055                 return -EFAULT;
4056
4057         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4058                 pr_err("btrfs: unable to set label with more than %d bytes\n",
4059                        BTRFS_LABEL_SIZE - 1);
4060                 return -EINVAL;
4061         }
4062
4063         ret = mnt_want_write_file(file);
4064         if (ret)
4065                 return ret;
4066
4067         mutex_lock(&root->fs_info->volume_mutex);
4068         trans = btrfs_start_transaction(root, 0);
4069         if (IS_ERR(trans)) {
4070                 ret = PTR_ERR(trans);
4071                 goto out_unlock;
4072         }
4073
4074         strcpy(super_block->label, label);
4075         ret = btrfs_end_transaction(trans, root);
4076
4077 out_unlock:
4078         mutex_unlock(&root->fs_info->volume_mutex);
4079         mnt_drop_write_file(file);
4080         return ret;
4081 }
4082
4083 long btrfs_ioctl(struct file *file, unsigned int
4084                 cmd, unsigned long arg)
4085 {
4086         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4087         void __user *argp = (void __user *)arg;
4088
4089         switch (cmd) {
4090         case FS_IOC_GETFLAGS:
4091                 return btrfs_ioctl_getflags(file, argp);
4092         case FS_IOC_SETFLAGS:
4093                 return btrfs_ioctl_setflags(file, argp);
4094         case FS_IOC_GETVERSION:
4095                 return btrfs_ioctl_getversion(file, argp);
4096         case FITRIM:
4097                 return btrfs_ioctl_fitrim(file, argp);
4098         case BTRFS_IOC_SNAP_CREATE:
4099                 return btrfs_ioctl_snap_create(file, argp, 0);
4100         case BTRFS_IOC_SNAP_CREATE_V2:
4101                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
4102         case BTRFS_IOC_SUBVOL_CREATE:
4103                 return btrfs_ioctl_snap_create(file, argp, 1);
4104         case BTRFS_IOC_SUBVOL_CREATE_V2:
4105                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
4106         case BTRFS_IOC_SNAP_DESTROY:
4107                 return btrfs_ioctl_snap_destroy(file, argp);
4108         case BTRFS_IOC_SUBVOL_GETFLAGS:
4109                 return btrfs_ioctl_subvol_getflags(file, argp);
4110         case BTRFS_IOC_SUBVOL_SETFLAGS:
4111                 return btrfs_ioctl_subvol_setflags(file, argp);
4112         case BTRFS_IOC_DEFAULT_SUBVOL:
4113                 return btrfs_ioctl_default_subvol(file, argp);
4114         case BTRFS_IOC_DEFRAG:
4115                 return btrfs_ioctl_defrag(file, NULL);
4116         case BTRFS_IOC_DEFRAG_RANGE:
4117                 return btrfs_ioctl_defrag(file, argp);
4118         case BTRFS_IOC_RESIZE:
4119                 return btrfs_ioctl_resize(file, argp);
4120         case BTRFS_IOC_ADD_DEV:
4121                 return btrfs_ioctl_add_dev(root, argp);
4122         case BTRFS_IOC_RM_DEV:
4123                 return btrfs_ioctl_rm_dev(file, argp);
4124         case BTRFS_IOC_FS_INFO:
4125                 return btrfs_ioctl_fs_info(root, argp);
4126         case BTRFS_IOC_DEV_INFO:
4127                 return btrfs_ioctl_dev_info(root, argp);
4128         case BTRFS_IOC_BALANCE:
4129                 return btrfs_ioctl_balance(file, NULL);
4130         case BTRFS_IOC_CLONE:
4131                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
4132         case BTRFS_IOC_CLONE_RANGE:
4133                 return btrfs_ioctl_clone_range(file, argp);
4134         case BTRFS_IOC_TRANS_START:
4135                 return btrfs_ioctl_trans_start(file);
4136         case BTRFS_IOC_TRANS_END:
4137                 return btrfs_ioctl_trans_end(file);
4138         case BTRFS_IOC_TREE_SEARCH:
4139                 return btrfs_ioctl_tree_search(file, argp);
4140         case BTRFS_IOC_INO_LOOKUP:
4141                 return btrfs_ioctl_ino_lookup(file, argp);
4142         case BTRFS_IOC_INO_PATHS:
4143                 return btrfs_ioctl_ino_to_path(root, argp);
4144         case BTRFS_IOC_LOGICAL_INO:
4145                 return btrfs_ioctl_logical_to_ino(root, argp);
4146         case BTRFS_IOC_SPACE_INFO:
4147                 return btrfs_ioctl_space_info(root, argp);
4148         case BTRFS_IOC_SYNC:
4149                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
4150                 return 0;
4151         case BTRFS_IOC_START_SYNC:
4152                 return btrfs_ioctl_start_sync(root, argp);
4153         case BTRFS_IOC_WAIT_SYNC:
4154                 return btrfs_ioctl_wait_sync(root, argp);
4155         case BTRFS_IOC_SCRUB:
4156                 return btrfs_ioctl_scrub(file, argp);
4157         case BTRFS_IOC_SCRUB_CANCEL:
4158                 return btrfs_ioctl_scrub_cancel(root, argp);
4159         case BTRFS_IOC_SCRUB_PROGRESS:
4160                 return btrfs_ioctl_scrub_progress(root, argp);
4161         case BTRFS_IOC_BALANCE_V2:
4162                 return btrfs_ioctl_balance(file, argp);
4163         case BTRFS_IOC_BALANCE_CTL:
4164                 return btrfs_ioctl_balance_ctl(root, arg);
4165         case BTRFS_IOC_BALANCE_PROGRESS:
4166                 return btrfs_ioctl_balance_progress(root, argp);
4167         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4168                 return btrfs_ioctl_set_received_subvol(file, argp);
4169         case BTRFS_IOC_SEND:
4170                 return btrfs_ioctl_send(file, argp);
4171         case BTRFS_IOC_GET_DEV_STATS:
4172                 return btrfs_ioctl_get_dev_stats(root, argp);
4173         case BTRFS_IOC_QUOTA_CTL:
4174                 return btrfs_ioctl_quota_ctl(file, argp);
4175         case BTRFS_IOC_QGROUP_ASSIGN:
4176                 return btrfs_ioctl_qgroup_assign(file, argp);
4177         case BTRFS_IOC_QGROUP_CREATE:
4178                 return btrfs_ioctl_qgroup_create(file, argp);
4179         case BTRFS_IOC_QGROUP_LIMIT:
4180                 return btrfs_ioctl_qgroup_limit(file, argp);
4181         case BTRFS_IOC_QUOTA_RESCAN:
4182                 return btrfs_ioctl_quota_rescan(file, argp);
4183         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
4184                 return btrfs_ioctl_quota_rescan_status(file, argp);
4185         case BTRFS_IOC_DEV_REPLACE:
4186                 return btrfs_ioctl_dev_replace(root, argp);
4187         case BTRFS_IOC_GET_FSLABEL:
4188                 return btrfs_ioctl_get_fslabel(file, argp);
4189         case BTRFS_IOC_SET_FSLABEL:
4190                 return btrfs_ioctl_set_fslabel(file, argp);
4191         }
4192
4193         return -ENOTTY;
4194 }