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 "compat.h"
  45 #include "ctree.h"
  46 #include "disk-io.h"
  47 #include "transaction.h"
  48 #include "btrfs_inode.h"
  49 #include "ioctl.h"
  50 #include "print-tree.h"
  51 #include "volumes.h"
  52 #include "locking.h"
  53 #include "inode-map.h"
  54 #include "backref.h"
  55 #include "rcu-string.h"
  56
  57 /* Mask out flags that are inappropriate for the given type of inode. */
  58 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  59 {
  60         if (S_ISDIR(mode))
  61                 return flags;
  62         else if (S_ISREG(mode))
  63                 return flags & ~FS_DIRSYNC_FL;
  64         else
  65                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  66 }
  67
  68 /*
  69  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  70  */
  71 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  72 {
  73         unsigned int iflags = 0;
  74
  75         if (flags & BTRFS_INODE_SYNC)
  76                 iflags |= FS_SYNC_FL;
  77         if (flags & BTRFS_INODE_IMMUTABLE)
  78                 iflags |= FS_IMMUTABLE_FL;
  79         if (flags & BTRFS_INODE_APPEND)
  80                 iflags |= FS_APPEND_FL;
  81         if (flags & BTRFS_INODE_NODUMP)
  82                 iflags |= FS_NODUMP_FL;
  83         if (flags & BTRFS_INODE_NOATIME)
  84                 iflags |= FS_NOATIME_FL;
  85         if (flags & BTRFS_INODE_DIRSYNC)
  86                 iflags |= FS_DIRSYNC_FL;
  87         if (flags & BTRFS_INODE_NODATACOW)
  88                 iflags |= FS_NOCOW_FL;
  89
  90         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
  91                 iflags |= FS_COMPR_FL;
  92         else if (flags & BTRFS_INODE_NOCOMPRESS)
  93                 iflags |= FS_NOCOMP_FL;
  94
  95         return iflags;
  96 }
  97
  98 /*
  99  * Update inode->i_flags based on the btrfs internal flags.
 100  */
 101 void btrfs_update_iflags(struct inode *inode)
 102 {
 103         struct btrfs_inode *ip = BTRFS_I(inode);
 104
 105         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 106
 107         if (ip->flags & BTRFS_INODE_SYNC)
 108                 inode->i_flags |= S_SYNC;
 109         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 110                 inode->i_flags |= S_IMMUTABLE;
 111         if (ip->flags & BTRFS_INODE_APPEND)
 112                 inode->i_flags |= S_APPEND;
 113         if (ip->flags & BTRFS_INODE_NOATIME)
 114                 inode->i_flags |= S_NOATIME;
 115         if (ip->flags & BTRFS_INODE_DIRSYNC)
 116                 inode->i_flags |= S_DIRSYNC;
 117 }
 118
 119 /*
 120  * Inherit flags from the parent inode.
 121  *
 122  * Currently only the compression flags and the cow flags are inherited.
 123  */
 124 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 125 {
 126         unsigned int flags;
 127
 128         if (!dir)
 129                 return;
 130
 131         flags = BTRFS_I(dir)->flags;
 132
 133         if (flags & BTRFS_INODE_NOCOMPRESS) {
 134                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 135                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 136         } else if (flags & BTRFS_INODE_COMPRESS) {
 137                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 138                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 139         }
 140
 141         if (flags & BTRFS_INODE_NODATACOW)
 142                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 143
 144         btrfs_update_iflags(inode);
 145 }
 146
 147 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 148 {
 149         struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
 150         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 151
 152         if (copy_to_user(arg, &flags, sizeof(flags)))
 153                 return -EFAULT;
 154         return 0;
 155 }
 156
 157 static int check_flags(unsigned int flags)
 158 {
 159         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 160                       FS_NOATIME_FL | FS_NODUMP_FL | \
 161                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 162                       FS_NOCOMP_FL | FS_COMPR_FL |
 163                       FS_NOCOW_FL))
 164                 return -EOPNOTSUPP;
 165
 166         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 167                 return -EINVAL;
 168
 169         return 0;
 170 }
 171
 172 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 173 {
 174         struct inode *inode = file->f_path.dentry->d_inode;
 175         struct btrfs_inode *ip = BTRFS_I(inode);
 176         struct btrfs_root *root = ip->root;
 177         struct btrfs_trans_handle *trans;
 178         unsigned int flags, oldflags;
 179         int ret;
 180         u64 ip_oldflags;
 181         unsigned int i_oldflags;
 182
 183         if (btrfs_root_readonly(root))
 184                 return -EROFS;
 185
 186         if (copy_from_user(&flags, arg, sizeof(flags)))
 187                 return -EFAULT;
 188
 189         ret = check_flags(flags);
 190         if (ret)
 191                 return ret;
 192
 193         if (!inode_owner_or_capable(inode))
 194                 return -EACCES;
 195
 196         mutex_lock(&inode->i_mutex);
 197
 198         ip_oldflags = ip->flags;
 199         i_oldflags = inode->i_flags;
 200
 201         flags = btrfs_mask_flags(inode->i_mode, flags);
 202         oldflags = btrfs_flags_to_ioctl(ip->flags);
 203         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 204                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 205                         ret = -EPERM;
 206                         goto out_unlock;
 207                 }
 208         }
 209
 210         ret = mnt_want_write_file(file);
 211         if (ret)
 212                 goto out_unlock;
 213
 214         if (flags & FS_SYNC_FL)
 215                 ip->flags |= BTRFS_INODE_SYNC;
 216         else
 217                 ip->flags &= ~BTRFS_INODE_SYNC;
 218         if (flags & FS_IMMUTABLE_FL)
 219                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 220         else
 221                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 222         if (flags & FS_APPEND_FL)
 223                 ip->flags |= BTRFS_INODE_APPEND;
 224         else
 225                 ip->flags &= ~BTRFS_INODE_APPEND;
 226         if (flags & FS_NODUMP_FL)
 227                 ip->flags |= BTRFS_INODE_NODUMP;
 228         else
 229                 ip->flags &= ~BTRFS_INODE_NODUMP;
 230         if (flags & FS_NOATIME_FL)
 231                 ip->flags |= BTRFS_INODE_NOATIME;
 232         else
 233                 ip->flags &= ~BTRFS_INODE_NOATIME;
 234         if (flags & FS_DIRSYNC_FL)
 235                 ip->flags |= BTRFS_INODE_DIRSYNC;
 236         else
 237                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 238         if (flags & FS_NOCOW_FL)
 239                 ip->flags |= BTRFS_INODE_NODATACOW;
 240         else
 241                 ip->flags &= ~BTRFS_INODE_NODATACOW;
 242
 243         /*
 244          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 245          * flag may be changed automatically if compression code won't make
 246          * things smaller.
 247          */
 248         if (flags & FS_NOCOMP_FL) {
 249                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 250                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 251         } else if (flags & FS_COMPR_FL) {
 252                 ip->flags |= BTRFS_INODE_COMPRESS;
 253                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 254         } else {
 255                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 256         }
 257
 258         trans = btrfs_start_transaction(root, 1);
 259         if (IS_ERR(trans)) {
 260                 ret = PTR_ERR(trans);
 261                 goto out_drop;
 262         }
 263
 264         btrfs_update_iflags(inode);
 265         inode_inc_iversion(inode);
 266         inode->i_ctime = CURRENT_TIME;
 267         ret = btrfs_update_inode(trans, root, inode);
 268
 269         btrfs_end_transaction(trans, root);
 270  out_drop:
 271         if (ret) {
 272                 ip->flags = ip_oldflags;
 273                 inode->i_flags = i_oldflags;
 274         }
 275
 276         mnt_drop_write_file(file);
 277  out_unlock:
 278         mutex_unlock(&inode->i_mutex);
 279         return ret;
 280 }
 281
 282 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 283 {
 284         struct inode *inode = file->f_path.dentry->d_inode;
 285
 286         return put_user(inode->i_generation, arg);
 287 }
 288
 289 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 290 {
 291         struct btrfs_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
 292         struct btrfs_device *device;
 293         struct request_queue *q;
 294         struct fstrim_range range;
 295         u64 minlen = ULLONG_MAX;
 296         u64 num_devices = 0;
 297         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 298         int ret;
 299
 300         if (!capable(CAP_SYS_ADMIN))
 301                 return -EPERM;
 302
 303         rcu_read_lock();
 304         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 305                                 dev_list) {
 306                 if (!device->bdev)
 307                         continue;
 308                 q = bdev_get_queue(device->bdev);
 309                 if (blk_queue_discard(q)) {
 310                         num_devices++;
 311                         minlen = min((u64)q->limits.discard_granularity,
 312                                      minlen);
 313                 }
 314         }
 315         rcu_read_unlock();
 316
 317         if (!num_devices)
 318                 return -EOPNOTSUPP;
 319         if (copy_from_user(&range, arg, sizeof(range)))
 320                 return -EFAULT;
 321         if (range.start > total_bytes)
 322                 return -EINVAL;
 323
 324         range.len = min(range.len, total_bytes - range.start);
 325         range.minlen = max(range.minlen, minlen);
 326         ret = btrfs_trim_fs(fs_info->tree_root, &range);
 327         if (ret < 0)
 328                 return ret;
 329
 330         if (copy_to_user(arg, &range, sizeof(range)))
 331                 return -EFAULT;
 332
 333         return 0;
 334 }
 335
 336 static noinline int create_subvol(struct btrfs_root *root,
 337                                   struct dentry *dentry,
 338                                   char *name, int namelen,
 339                                   u64 *async_transid)
 340 {
 341         struct btrfs_trans_handle *trans;
 342         struct btrfs_key key;
 343         struct btrfs_root_item root_item;
 344         struct btrfs_inode_item *inode_item;
 345         struct extent_buffer *leaf;
 346         struct btrfs_root *new_root;
 347         struct dentry *parent = dentry->d_parent;
 348         struct inode *dir;
 349         int ret;
 350         int err;
 351         u64 objectid;
 352         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 353         u64 index = 0;
 354
 355         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 356         if (ret)
 357                 return ret;
 358
 359         dir = parent->d_inode;
 360
 361         /*
 362          * 1 - inode item
 363          * 2 - refs
 364          * 1 - root item
 365          * 2 - dir items
 366          */
 367         trans = btrfs_start_transaction(root, 6);
 368         if (IS_ERR(trans))
 369                 return PTR_ERR(trans);
 370
 371         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 372                                       0, objectid, NULL, 0, 0, 0);
 373         if (IS_ERR(leaf)) {
 374                 ret = PTR_ERR(leaf);
 375                 goto fail;
 376         }
 377
 378         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 379         btrfs_set_header_bytenr(leaf, leaf->start);
 380         btrfs_set_header_generation(leaf, trans->transid);
 381         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 382         btrfs_set_header_owner(leaf, objectid);
 383
 384         write_extent_buffer(leaf, root->fs_info->fsid,
 385                             (unsigned long)btrfs_header_fsid(leaf),
 386                             BTRFS_FSID_SIZE);
 387         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 388                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 389                             BTRFS_UUID_SIZE);
 390         btrfs_mark_buffer_dirty(leaf);
 391
 392         inode_item = &root_item.inode;
 393         memset(inode_item, 0, sizeof(*inode_item));
 394         inode_item->generation = cpu_to_le64(1);
 395         inode_item->size = cpu_to_le64(3);
 396         inode_item->nlink = cpu_to_le32(1);
 397         inode_item->nbytes = cpu_to_le64(root->leafsize);
 398         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 399
 400         root_item.flags = 0;
 401         root_item.byte_limit = 0;
 402         inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
 403
 404         btrfs_set_root_bytenr(&root_item, leaf->start);
 405         btrfs_set_root_generation(&root_item, trans->transid);
 406         btrfs_set_root_level(&root_item, 0);
 407         btrfs_set_root_refs(&root_item, 1);
 408         btrfs_set_root_used(&root_item, leaf->len);
 409         btrfs_set_root_last_snapshot(&root_item, 0);
 410
 411         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 412         root_item.drop_level = 0;
 413
 414         btrfs_tree_unlock(leaf);
 415         free_extent_buffer(leaf);
 416         leaf = NULL;
 417
 418         btrfs_set_root_dirid(&root_item, new_dirid);
 419
 420         key.objectid = objectid;
 421         key.offset = 0;
 422         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 423         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 424                                 &root_item);
 425         if (ret)
 426                 goto fail;
 427
 428         key.offset = (u64)-1;
 429         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 430         if (IS_ERR(new_root)) {
 431                 btrfs_abort_transaction(trans, root, PTR_ERR(new_root));
 432                 ret = PTR_ERR(new_root);
 433                 goto fail;
 434         }
 435
 436         btrfs_record_root_in_trans(trans, new_root);
 437
 438         ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
 439         if (ret) {
 440                 /* We potentially lose an unused inode item here */
 441                 btrfs_abort_transaction(trans, root, ret);
 442                 goto fail;
 443         }
 444
 445         /*
 446          * insert the directory item
 447          */
 448         ret = btrfs_set_inode_index(dir, &index);
 449         if (ret) {
 450                 btrfs_abort_transaction(trans, root, ret);
 451                 goto fail;
 452         }
 453
 454         ret = btrfs_insert_dir_item(trans, root,
 455                                     name, namelen, dir, &key,
 456                                     BTRFS_FT_DIR, index);
 457         if (ret) {
 458                 btrfs_abort_transaction(trans, root, ret);
 459                 goto fail;
 460         }
 461
 462         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 463         ret = btrfs_update_inode(trans, root, dir);
 464         BUG_ON(ret);
 465
 466         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 467                                  objectid, root->root_key.objectid,
 468                                  btrfs_ino(dir), index, name, namelen);
 469
 470         BUG_ON(ret);
 471
 472         d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 473 fail:
 474         if (async_transid) {
 475                 *async_transid = trans->transid;
 476                 err = btrfs_commit_transaction_async(trans, root, 1);
 477         } else {
 478                 err = btrfs_commit_transaction(trans, root);
 479         }
 480         if (err && !ret)
 481                 ret = err;
 482         return ret;
 483 }
 484
 485 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 486                            char *name, int namelen, u64 *async_transid,
 487                            bool readonly)
 488 {
 489         struct inode *inode;
 490         struct btrfs_pending_snapshot *pending_snapshot;
 491         struct btrfs_trans_handle *trans;
 492         int ret;
 493
 494         if (!root->ref_cows)
 495                 return -EINVAL;
 496
 497         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 498         if (!pending_snapshot)
 499                 return -ENOMEM;
 500
 501         btrfs_init_block_rsv(&pending_snapshot->block_rsv);
 502         pending_snapshot->dentry = dentry;
 503         pending_snapshot->root = root;
 504         pending_snapshot->readonly = readonly;
 505
 506         trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
 507         if (IS_ERR(trans)) {
 508                 ret = PTR_ERR(trans);
 509                 goto fail;
 510         }
 511
 512         ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
 513         BUG_ON(ret);
 514
 515         spin_lock(&root->fs_info->trans_lock);
 516         list_add(&pending_snapshot->list,
 517                  &trans->transaction->pending_snapshots);
 518         spin_unlock(&root->fs_info->trans_lock);
 519         if (async_transid) {
 520                 *async_transid = trans->transid;
 521                 ret = btrfs_commit_transaction_async(trans,
 522                                      root->fs_info->extent_root, 1);
 523         } else {
 524                 ret = btrfs_commit_transaction(trans,
 525                                                root->fs_info->extent_root);
 526         }
 527         BUG_ON(ret);
 528
 529         ret = pending_snapshot->error;
 530         if (ret)
 531                 goto fail;
 532
 533         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 534         if (ret)
 535                 goto fail;
 536
 537         inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 538         if (IS_ERR(inode)) {
 539                 ret = PTR_ERR(inode);
 540                 goto fail;
 541         }
 542         BUG_ON(!inode);
 543         d_instantiate(dentry, inode);
 544         ret = 0;
 545 fail:
 546         kfree(pending_snapshot);
 547         return ret;
 548 }
 549
 550 /*  copy of check_sticky in fs/namei.c()
 551 * It's inline, so penalty for filesystems that don't use sticky bit is
 552 * minimal.
 553 */
 554 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
 555 {
 556         uid_t fsuid = current_fsuid();
 557
 558         if (!(dir->i_mode & S_ISVTX))
 559                 return 0;
 560         if (inode->i_uid == fsuid)
 561                 return 0;
 562         if (dir->i_uid == fsuid)
 563                 return 0;
 564         return !capable(CAP_FOWNER);
 565 }
 566
 567 /*  copy of may_delete in fs/namei.c()
 568  *      Check whether we can remove a link victim from directory dir, check
 569  *  whether the type of victim is right.
 570  *  1. We can't do it if dir is read-only (done in permission())
 571  *  2. We should have write and exec permissions on dir
 572  *  3. We can't remove anything from append-only dir
 573  *  4. We can't do anything with immutable dir (done in permission())
 574  *  5. If the sticky bit on dir is set we should either
 575  *      a. be owner of dir, or
 576  *      b. be owner of victim, or
 577  *      c. have CAP_FOWNER capability
 578  *  6. If the victim is append-only or immutable we can't do antyhing with
 579  *     links pointing to it.
 580  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 581  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 582  *  9. We can't remove a root or mountpoint.
 583  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 584  *     nfs_async_unlink().
 585  */
 586
 587 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
 588 {
 589         int error;
 590
 591         if (!victim->d_inode)
 592                 return -ENOENT;
 593
 594         BUG_ON(victim->d_parent->d_inode != dir);
 595         audit_inode_child(victim, dir);
 596
 597         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 598         if (error)
 599                 return error;
 600         if (IS_APPEND(dir))
 601                 return -EPERM;
 602         if (btrfs_check_sticky(dir, victim->d_inode)||
 603                 IS_APPEND(victim->d_inode)||
 604             IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
 605                 return -EPERM;
 606         if (isdir) {
 607                 if (!S_ISDIR(victim->d_inode->i_mode))
 608                         return -ENOTDIR;
 609                 if (IS_ROOT(victim))
 610                         return -EBUSY;
 611         } else if (S_ISDIR(victim->d_inode->i_mode))
 612                 return -EISDIR;
 613         if (IS_DEADDIR(dir))
 614                 return -ENOENT;
 615         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 616                 return -EBUSY;
 617         return 0;
 618 }
 619
 620 /* copy of may_create in fs/namei.c() */
 621 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 622 {
 623         if (child->d_inode)
 624                 return -EEXIST;
 625         if (IS_DEADDIR(dir))
 626                 return -ENOENT;
 627         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 628 }
 629
 630 /*
 631  * Create a new subvolume below @parent.  This is largely modeled after
 632  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 633  * inside this filesystem so it's quite a bit simpler.
 634  */
 635 static noinline int btrfs_mksubvol(struct path *parent,
 636                                    char *name, int namelen,
 637                                    struct btrfs_root *snap_src,
 638                                    u64 *async_transid, bool readonly)
 639 {
 640         struct inode *dir  = parent->dentry->d_inode;
 641         struct dentry *dentry;
 642         int error;
 643
 644         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 645
 646         dentry = lookup_one_len(name, parent->dentry, namelen);
 647         error = PTR_ERR(dentry);
 648         if (IS_ERR(dentry))
 649                 goto out_unlock;
 650
 651         error = -EEXIST;
 652         if (dentry->d_inode)
 653                 goto out_dput;
 654
 655         error = mnt_want_write(parent->mnt);
 656         if (error)
 657                 goto out_dput;
 658
 659         error = btrfs_may_create(dir, dentry);
 660         if (error)
 661                 goto out_drop_write;
 662
 663         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 664
 665         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 666                 goto out_up_read;
 667
 668         if (snap_src) {
 669                 error = create_snapshot(snap_src, dentry,
 670                                         name, namelen, async_transid, readonly);
 671         } else {
 672                 error = create_subvol(BTRFS_I(dir)->root, dentry,
 673                                       name, namelen, async_transid);
 674         }
 675         if (!error)
 676                 fsnotify_mkdir(dir, dentry);
 677 out_up_read:
 678         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 679 out_drop_write:
 680         mnt_drop_write(parent->mnt);
 681 out_dput:
 682         dput(dentry);
 683 out_unlock:
 684         mutex_unlock(&dir->i_mutex);
 685         return error;
 686 }
 687
 688 /*
 689  * When we're defragging a range, we don't want to kick it off again
 690  * if it is really just waiting for delalloc to send it down.
 691  * If we find a nice big extent or delalloc range for the bytes in the
 692  * file you want to defrag, we return 0 to let you know to skip this
 693  * part of the file
 694  */
 695 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
 696 {
 697         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 698         struct extent_map *em = NULL;
 699         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 700         u64 end;
 701
 702         read_lock(&em_tree->lock);
 703         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 704         read_unlock(&em_tree->lock);
 705
 706         if (em) {
 707                 end = extent_map_end(em);
 708                 free_extent_map(em);
 709                 if (end - offset > thresh)
 710                         return 0;
 711         }
 712         /* if we already have a nice delalloc here, just stop */
 713         thresh /= 2;
 714         end = count_range_bits(io_tree, &offset, offset + thresh,
 715                                thresh, EXTENT_DELALLOC, 1);
 716         if (end >= thresh)
 717                 return 0;
 718         return 1;
 719 }
 720
 721 /*
 722  * helper function to walk through a file and find extents
 723  * newer than a specific transid, and smaller than thresh.
 724  *
 725  * This is used by the defragging code to find new and small
 726  * extents
 727  */
 728 static int find_new_extents(struct btrfs_root *root,
 729                             struct inode *inode, u64 newer_than,
 730                             u64 *off, int thresh)
 731 {
 732         struct btrfs_path *path;
 733         struct btrfs_key min_key;
 734         struct btrfs_key max_key;
 735         struct extent_buffer *leaf;
 736         struct btrfs_file_extent_item *extent;
 737         int type;
 738         int ret;
 739         u64 ino = btrfs_ino(inode);
 740
 741         path = btrfs_alloc_path();
 742         if (!path)
 743                 return -ENOMEM;
 744
 745         min_key.objectid = ino;
 746         min_key.type = BTRFS_EXTENT_DATA_KEY;
 747         min_key.offset = *off;
 748
 749         max_key.objectid = ino;
 750         max_key.type = (u8)-1;
 751         max_key.offset = (u64)-1;
 752
 753         path->keep_locks = 1;
 754
 755         while(1) {
 756                 ret = btrfs_search_forward(root, &min_key, &max_key,
 757                                            path, 0, newer_than);
 758                 if (ret != 0)
 759                         goto none;
 760                 if (min_key.objectid != ino)
 761                         goto none;
 762                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 763                         goto none;
 764
 765                 leaf = path->nodes[0];
 766                 extent = btrfs_item_ptr(leaf, path->slots[0],
 767                                         struct btrfs_file_extent_item);
 768
 769                 type = btrfs_file_extent_type(leaf, extent);
 770                 if (type == BTRFS_FILE_EXTENT_REG &&
 771                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 772                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 773                         *off = min_key.offset;
 774                         btrfs_free_path(path);
 775                         return 0;
 776                 }
 777
 778                 if (min_key.offset == (u64)-1)
 779                         goto none;
 780
 781                 min_key.offset++;
 782                 btrfs_release_path(path);
 783         }
 784 none:
 785         btrfs_free_path(path);
 786         return -ENOENT;
 787 }
 788
 789 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 790 {
 791         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 792         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 793         struct extent_map *em;
 794         u64 len = PAGE_CACHE_SIZE;
 795
 796         /*
 797          * hopefully we have this extent in the tree already, try without
 798          * the full extent lock
 799          */
 800         read_lock(&em_tree->lock);
 801         em = lookup_extent_mapping(em_tree, start, len);
 802         read_unlock(&em_tree->lock);
 803
 804         if (!em) {
 805                 /* get the big lock and read metadata off disk */
 806                 lock_extent(io_tree, start, start + len - 1);
 807                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 808                 unlock_extent(io_tree, start, start + len - 1);
 809
 810                 if (IS_ERR(em))
 811                         return NULL;
 812         }
 813
 814         return em;
 815 }
 816
 817 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 818 {
 819         struct extent_map *next;
 820         bool ret = true;
 821
 822         /* this is the last extent */
 823         if (em->start + em->len >= i_size_read(inode))
 824                 return false;
 825
 826         next = defrag_lookup_extent(inode, em->start + em->len);
 827         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
 828                 ret = false;
 829
 830         free_extent_map(next);
 831         return ret;
 832 }
 833
 834 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
 835                                u64 *last_len, u64 *skip, u64 *defrag_end)
 836 {
 837         struct extent_map *em;
 838         int ret = 1;
 839         bool next_mergeable = true;
 840
 841         /*
 842          * make sure that once we start defragging an extent, we keep on
 843          * defragging it
 844          */
 845         if (start < *defrag_end)
 846                 return 1;
 847
 848         *skip = 0;
 849
 850         em = defrag_lookup_extent(inode, start);
 851         if (!em)
 852                 return 0;
 853
 854         /* this will cover holes, and inline extents */
 855         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
 856                 ret = 0;
 857                 goto out;
 858         }
 859
 860         next_mergeable = defrag_check_next_extent(inode, em);
 861
 862         /*
 863          * we hit a real extent, if it is big or the next extent is not a
 864          * real extent, don't bother defragging it
 865          */
 866         if ((*last_len == 0 || *last_len >= thresh) &&
 867             (em->len >= thresh || !next_mergeable))
 868                 ret = 0;
 869 out:
 870         /*
 871          * last_len ends up being a counter of how many bytes we've defragged.
 872          * every time we choose not to defrag an extent, we reset *last_len
 873          * so that the next tiny extent will force a defrag.
 874          *
 875          * The end result of this is that tiny extents before a single big
 876          * extent will force at least part of that big extent to be defragged.
 877          */
 878         if (ret) {
 879                 *defrag_end = extent_map_end(em);
 880         } else {
 881                 *last_len = 0;
 882                 *skip = extent_map_end(em);
 883                 *defrag_end = 0;
 884         }
 885
 886         free_extent_map(em);
 887         return ret;
 888 }
 889
 890 /*
 891  * it doesn't do much good to defrag one or two pages
 892  * at a time.  This pulls in a nice chunk of pages
 893  * to COW and defrag.
 894  *
 895  * It also makes sure the delalloc code has enough
 896  * dirty data to avoid making new small extents as part
 897  * of the defrag
 898  *
 899  * It's a good idea to start RA on this range
 900  * before calling this.
 901  */
 902 static int cluster_pages_for_defrag(struct inode *inode,
 903                                     struct page **pages,
 904                                     unsigned long start_index,
 905                                     int num_pages)
 906 {
 907         unsigned long file_end;
 908         u64 isize = i_size_read(inode);
 909         u64 page_start;
 910         u64 page_end;
 911         u64 page_cnt;
 912         int ret;
 913         int i;
 914         int i_done;
 915         struct btrfs_ordered_extent *ordered;
 916         struct extent_state *cached_state = NULL;
 917         struct extent_io_tree *tree;
 918         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 919
 920         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
 921         if (!isize || start_index > file_end)
 922                 return 0;
 923
 924         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
 925
 926         ret = btrfs_delalloc_reserve_space(inode,
 927                                            page_cnt << PAGE_CACHE_SHIFT);
 928         if (ret)
 929                 return ret;
 930         i_done = 0;
 931         tree = &BTRFS_I(inode)->io_tree;
 932
 933         /* step one, lock all the pages */
 934         for (i = 0; i < page_cnt; i++) {
 935                 struct page *page;
 936 again:
 937                 page = find_or_create_page(inode->i_mapping,
 938                                            start_index + i, mask);
 939                 if (!page)
 940                         break;
 941
 942                 page_start = page_offset(page);
 943                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 944                 while (1) {
 945                         lock_extent(tree, page_start, page_end);
 946                         ordered = btrfs_lookup_ordered_extent(inode,
 947                                                               page_start);
 948                         unlock_extent(tree, page_start, page_end);
 949                         if (!ordered)
 950                                 break;
 951
 952                         unlock_page(page);
 953                         btrfs_start_ordered_extent(inode, ordered, 1);
 954                         btrfs_put_ordered_extent(ordered);
 955                         lock_page(page);
 956                         /*
 957                          * we unlocked the page above, so we need check if
 958                          * it was released or not.
 959                          */
 960                         if (page->mapping != inode->i_mapping) {
 961                                 unlock_page(page);
 962                                 page_cache_release(page);
 963                                 goto again;
 964                         }
 965                 }
 966
 967                 if (!PageUptodate(page)) {
 968                         btrfs_readpage(NULL, page);
 969                         lock_page(page);
 970                         if (!PageUptodate(page)) {
 971                                 unlock_page(page);
 972                                 page_cache_release(page);
 973                                 ret = -EIO;
 974                                 break;
 975                         }
 976                 }
 977
 978                 if (page->mapping != inode->i_mapping) {
 979                         unlock_page(page);
 980                         page_cache_release(page);
 981                         goto again;
 982                 }
 983
 984                 pages[i] = page;
 985                 i_done++;
 986         }
 987         if (!i_done || ret)
 988                 goto out;
 989
 990         if (!(inode->i_sb->s_flags & MS_ACTIVE))
 991                 goto out;
 992
 993         /*
 994          * so now we have a nice long stream of locked
 995          * and up to date pages, lets wait on them
 996          */
 997         for (i = 0; i < i_done; i++)
 998                 wait_on_page_writeback(pages[i]);
 999
1000         page_start = page_offset(pages[0]);
1001         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1002
1003         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1004                          page_start, page_end - 1, 0, &cached_state);
1005         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1006                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1007                           EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
1008                           GFP_NOFS);
1009
1010         if (i_done != page_cnt) {
1011                 spin_lock(&BTRFS_I(inode)->lock);
1012                 BTRFS_I(inode)->outstanding_extents++;
1013                 spin_unlock(&BTRFS_I(inode)->lock);
1014                 btrfs_delalloc_release_space(inode,
1015                                      (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1016         }
1017
1018
1019         btrfs_set_extent_delalloc(inode, page_start, page_end - 1,
1020                                   &cached_state);
1021
1022         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1023                              page_start, page_end - 1, &cached_state,
1024                              GFP_NOFS);
1025
1026         for (i = 0; i < i_done; i++) {
1027                 clear_page_dirty_for_io(pages[i]);
1028                 ClearPageChecked(pages[i]);
1029                 set_page_extent_mapped(pages[i]);
1030                 set_page_dirty(pages[i]);
1031                 unlock_page(pages[i]);
1032                 page_cache_release(pages[i]);
1033         }
1034         return i_done;
1035 out:
1036         for (i = 0; i < i_done; i++) {
1037                 unlock_page(pages[i]);
1038                 page_cache_release(pages[i]);
1039         }
1040         btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1041         return ret;
1042
1043 }
1044
1045 int btrfs_defrag_file(struct inode *inode, struct file *file,
1046                       struct btrfs_ioctl_defrag_range_args *range,
1047                       u64 newer_than, unsigned long max_to_defrag)
1048 {
1049         struct btrfs_root *root = BTRFS_I(inode)->root;
1050         struct btrfs_super_block *disk_super;
1051         struct file_ra_state *ra = NULL;
1052         unsigned long last_index;
1053         u64 isize = i_size_read(inode);
1054         u64 features;
1055         u64 last_len = 0;
1056         u64 skip = 0;
1057         u64 defrag_end = 0;
1058         u64 newer_off = range->start;
1059         unsigned long i;
1060         unsigned long ra_index = 0;
1061         int ret;
1062         int defrag_count = 0;
1063         int compress_type = BTRFS_COMPRESS_ZLIB;
1064         int extent_thresh = range->extent_thresh;
1065         int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1066         int cluster = max_cluster;
1067         u64 new_align = ~((u64)128 * 1024 - 1);
1068         struct page **pages = NULL;
1069
1070         if (extent_thresh == 0)
1071                 extent_thresh = 256 * 1024;
1072
1073         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1074                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1075                         return -EINVAL;
1076                 if (range->compress_type)
1077                         compress_type = range->compress_type;
1078         }
1079
1080         if (isize == 0)
1081                 return 0;
1082
1083         /*
1084          * if we were not given a file, allocate a readahead
1085          * context
1086          */
1087         if (!file) {
1088                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1089                 if (!ra)
1090                         return -ENOMEM;
1091                 file_ra_state_init(ra, inode->i_mapping);
1092         } else {
1093                 ra = &file->f_ra;
1094         }
1095
1096         pages = kmalloc(sizeof(struct page *) * max_cluster,
1097                         GFP_NOFS);
1098         if (!pages) {
1099                 ret = -ENOMEM;
1100                 goto out_ra;
1101         }
1102
1103         /* find the last page to defrag */
1104         if (range->start + range->len > range->start) {
1105                 last_index = min_t(u64, isize - 1,
1106                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1107         } else {
1108                 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1109         }
1110
1111         if (newer_than) {
1112                 ret = find_new_extents(root, inode, newer_than,
1113                                        &newer_off, 64 * 1024);
1114                 if (!ret) {
1115                         range->start = newer_off;
1116                         /*
1117                          * we always align our defrag to help keep
1118                          * the extents in the file evenly spaced
1119                          */
1120                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1121                 } else
1122                         goto out_ra;
1123         } else {
1124                 i = range->start >> PAGE_CACHE_SHIFT;
1125         }
1126         if (!max_to_defrag)
1127                 max_to_defrag = last_index + 1;
1128
1129         /*
1130          * make writeback starts from i, so the defrag range can be
1131          * written sequentially.
1132          */
1133         if (i < inode->i_mapping->writeback_index)
1134                 inode->i_mapping->writeback_index = i;
1135
1136         while (i <= last_index && defrag_count < max_to_defrag &&
1137                (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1138                 PAGE_CACHE_SHIFT)) {
1139                 /*
1140                  * make sure we stop running if someone unmounts
1141                  * the FS
1142                  */
1143                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1144                         break;
1145
1146                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1147                                          extent_thresh, &last_len, &skip,
1148                                          &defrag_end)) {
1149                         unsigned long next;
1150                         /*
1151                          * the should_defrag function tells us how much to skip
1152                          * bump our counter by the suggested amount
1153                          */
1154                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1155                         i = max(i + 1, next);
1156                         continue;
1157                 }
1158
1159                 if (!newer_than) {
1160                         cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1161                                    PAGE_CACHE_SHIFT) - i;
1162                         cluster = min(cluster, max_cluster);
1163                 } else {
1164                         cluster = max_cluster;
1165                 }
1166
1167                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1168                         BTRFS_I(inode)->force_compress = compress_type;
1169
1170                 if (i + cluster > ra_index) {
1171                         ra_index = max(i, ra_index);
1172                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1173                                        cluster);
1174                         ra_index += max_cluster;
1175                 }
1176
1177                 mutex_lock(&inode->i_mutex);
1178                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1179                 if (ret < 0) {
1180                         mutex_unlock(&inode->i_mutex);
1181                         goto out_ra;
1182                 }
1183
1184                 defrag_count += ret;
1185                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1186                 mutex_unlock(&inode->i_mutex);
1187
1188                 if (newer_than) {
1189                         if (newer_off == (u64)-1)
1190                                 break;
1191
1192                         if (ret > 0)
1193                                 i += ret;
1194
1195                         newer_off = max(newer_off + 1,
1196                                         (u64)i << PAGE_CACHE_SHIFT);
1197
1198                         ret = find_new_extents(root, inode,
1199                                                newer_than, &newer_off,
1200                                                64 * 1024);
1201                         if (!ret) {
1202                                 range->start = newer_off;
1203                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1204                         } else {
1205                                 break;
1206                         }
1207                 } else {
1208                         if (ret > 0) {
1209                                 i += ret;
1210                                 last_len += ret << PAGE_CACHE_SHIFT;
1211                         } else {
1212                                 i++;
1213                                 last_len = 0;
1214                         }
1215                 }
1216         }
1217
1218         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1219                 filemap_flush(inode->i_mapping);
1220
1221         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1222                 /* the filemap_flush will queue IO into the worker threads, but
1223                  * we have to make sure the IO is actually started and that
1224                  * ordered extents get created before we return
1225                  */
1226                 atomic_inc(&root->fs_info->async_submit_draining);
1227                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1228                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1229                         wait_event(root->fs_info->async_submit_wait,
1230                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1231                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1232                 }
1233                 atomic_dec(&root->fs_info->async_submit_draining);
1234
1235                 mutex_lock(&inode->i_mutex);
1236                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1237                 mutex_unlock(&inode->i_mutex);
1238         }
1239
1240         disk_super = root->fs_info->super_copy;
1241         features = btrfs_super_incompat_flags(disk_super);
1242         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1243                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1244                 btrfs_set_super_incompat_flags(disk_super, features);
1245         }
1246
1247         ret = defrag_count;
1248
1249 out_ra:
1250         if (!file)
1251                 kfree(ra);
1252         kfree(pages);
1253         return ret;
1254 }
1255
1256 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1257                                         void __user *arg)
1258 {
1259         u64 new_size;
1260         u64 old_size;
1261         u64 devid = 1;
1262         struct btrfs_ioctl_vol_args *vol_args;
1263         struct btrfs_trans_handle *trans;
1264         struct btrfs_device *device = NULL;
1265         char *sizestr;
1266         char *devstr = NULL;
1267         int ret = 0;
1268         int mod = 0;
1269
1270         if (root->fs_info->sb->s_flags & MS_RDONLY)
1271                 return -EROFS;
1272
1273         if (!capable(CAP_SYS_ADMIN))
1274                 return -EPERM;
1275
1276         mutex_lock(&root->fs_info->volume_mutex);
1277         if (root->fs_info->balance_ctl) {
1278                 printk(KERN_INFO "btrfs: balance in progress\n");
1279                 ret = -EINVAL;
1280                 goto out;
1281         }
1282
1283         vol_args = memdup_user(arg, sizeof(*vol_args));
1284         if (IS_ERR(vol_args)) {
1285                 ret = PTR_ERR(vol_args);
1286                 goto out;
1287         }
1288
1289         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1290
1291         sizestr = vol_args->name;
1292         devstr = strchr(sizestr, ':');
1293         if (devstr) {
1294                 char *end;
1295                 sizestr = devstr + 1;
1296                 *devstr = '\0';
1297                 devstr = vol_args->name;
1298                 devid = simple_strtoull(devstr, &end, 10);
1299                 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1300                        (unsigned long long)devid);
1301         }
1302         device = btrfs_find_device(root, devid, NULL, NULL);
1303         if (!device) {
1304                 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1305                        (unsigned long long)devid);
1306                 ret = -EINVAL;
1307                 goto out_free;
1308         }
1309         if (device->fs_devices && device->fs_devices->seeding) {
1310                 printk(KERN_INFO "btrfs: resizer unable to apply on "
1311                        "seeding device %llu\n",
1312                        (unsigned long long)devid);
1313                 ret = -EINVAL;
1314                 goto out_free;
1315         }
1316
1317         if (!strcmp(sizestr, "max"))
1318                 new_size = device->bdev->bd_inode->i_size;
1319         else {
1320                 if (sizestr[0] == '-') {
1321                         mod = -1;
1322                         sizestr++;
1323                 } else if (sizestr[0] == '+') {
1324                         mod = 1;
1325                         sizestr++;
1326                 }
1327                 new_size = memparse(sizestr, NULL);
1328                 if (new_size == 0) {
1329                         ret = -EINVAL;
1330                         goto out_free;
1331                 }
1332         }
1333
1334         old_size = device->total_bytes;
1335
1336         if (mod < 0) {
1337                 if (new_size > old_size) {
1338                         ret = -EINVAL;
1339                         goto out_free;
1340                 }
1341                 new_size = old_size - new_size;
1342         } else if (mod > 0) {
1343                 new_size = old_size + new_size;
1344         }
1345
1346         if (new_size < 256 * 1024 * 1024) {
1347                 ret = -EINVAL;
1348                 goto out_free;
1349         }
1350         if (new_size > device->bdev->bd_inode->i_size) {
1351                 ret = -EFBIG;
1352                 goto out_free;
1353         }
1354
1355         do_div(new_size, root->sectorsize);
1356         new_size *= root->sectorsize;
1357
1358         printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
1359                       rcu_str_deref(device->name),
1360                       (unsigned long long)new_size);
1361
1362         if (new_size > old_size) {
1363                 trans = btrfs_start_transaction(root, 0);
1364                 if (IS_ERR(trans)) {
1365                         ret = PTR_ERR(trans);
1366                         goto out_free;
1367                 }
1368                 ret = btrfs_grow_device(trans, device, new_size);
1369                 btrfs_commit_transaction(trans, root);
1370         } else if (new_size < old_size) {
1371                 ret = btrfs_shrink_device(device, new_size);
1372         }
1373
1374 out_free:
1375         kfree(vol_args);
1376 out:
1377         mutex_unlock(&root->fs_info->volume_mutex);
1378         return ret;
1379 }
1380
1381 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1382                                                     char *name,
1383                                                     unsigned long fd,
1384                                                     int subvol,
1385                                                     u64 *transid,
1386                                                     bool readonly)
1387 {
1388         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1389         struct file *src_file;
1390         int namelen;
1391         int ret = 0;
1392
1393         if (root->fs_info->sb->s_flags & MS_RDONLY)
1394                 return -EROFS;
1395
1396         namelen = strlen(name);
1397         if (strchr(name, '/')) {
1398                 ret = -EINVAL;
1399                 goto out;
1400         }
1401
1402         if (name[0] == '.' &&
1403            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1404                 ret = -EEXIST;
1405                 goto out;
1406         }
1407
1408         if (subvol) {
1409                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1410                                      NULL, transid, readonly);
1411         } else {
1412                 struct inode *src_inode;
1413                 src_file = fget(fd);
1414                 if (!src_file) {
1415                         ret = -EINVAL;
1416                         goto out;
1417                 }
1418
1419                 src_inode = src_file->f_path.dentry->d_inode;
1420                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1421                         printk(KERN_INFO "btrfs: Snapshot src from "
1422                                "another FS\n");
1423                         ret = -EINVAL;
1424                         fput(src_file);
1425                         goto out;
1426                 }
1427                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1428                                      BTRFS_I(src_inode)->root,
1429                                      transid, readonly);
1430                 fput(src_file);
1431         }
1432 out:
1433         return ret;
1434 }
1435
1436 static noinline int btrfs_ioctl_snap_create(struct file *file,
1437                                             void __user *arg, int subvol)
1438 {
1439         struct btrfs_ioctl_vol_args *vol_args;
1440         int ret;
1441
1442         vol_args = memdup_user(arg, sizeof(*vol_args));
1443         if (IS_ERR(vol_args))
1444                 return PTR_ERR(vol_args);
1445         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1446
1447         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1448                                               vol_args->fd, subvol,
1449                                               NULL, false);
1450
1451         kfree(vol_args);
1452         return ret;
1453 }
1454
1455 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1456                                                void __user *arg, int subvol)
1457 {
1458         struct btrfs_ioctl_vol_args_v2 *vol_args;
1459         int ret;
1460         u64 transid = 0;
1461         u64 *ptr = NULL;
1462         bool readonly = false;
1463
1464         vol_args = memdup_user(arg, sizeof(*vol_args));
1465         if (IS_ERR(vol_args))
1466                 return PTR_ERR(vol_args);
1467         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1468
1469         if (vol_args->flags &
1470             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1471                 ret = -EOPNOTSUPP;
1472                 goto out;
1473         }
1474
1475         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1476                 ptr = &transid;
1477         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1478                 readonly = true;
1479
1480         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1481                                               vol_args->fd, subvol,
1482                                               ptr, readonly);
1483
1484         if (ret == 0 && ptr &&
1485             copy_to_user(arg +
1486                          offsetof(struct btrfs_ioctl_vol_args_v2,
1487                                   transid), ptr, sizeof(*ptr)))
1488                 ret = -EFAULT;
1489 out:
1490         kfree(vol_args);
1491         return ret;
1492 }
1493
1494 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1495                                                 void __user *arg)
1496 {
1497         struct inode *inode = fdentry(file)->d_inode;
1498         struct btrfs_root *root = BTRFS_I(inode)->root;
1499         int ret = 0;
1500         u64 flags = 0;
1501
1502         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1503                 return -EINVAL;
1504
1505         down_read(&root->fs_info->subvol_sem);
1506         if (btrfs_root_readonly(root))
1507                 flags |= BTRFS_SUBVOL_RDONLY;
1508         up_read(&root->fs_info->subvol_sem);
1509
1510         if (copy_to_user(arg, &flags, sizeof(flags)))
1511                 ret = -EFAULT;
1512
1513         return ret;
1514 }
1515
1516 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1517                                               void __user *arg)
1518 {
1519         struct inode *inode = fdentry(file)->d_inode;
1520         struct btrfs_root *root = BTRFS_I(inode)->root;
1521         struct btrfs_trans_handle *trans;
1522         u64 root_flags;
1523         u64 flags;
1524         int ret = 0;
1525
1526         if (root->fs_info->sb->s_flags & MS_RDONLY)
1527                 return -EROFS;
1528
1529         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1530                 return -EINVAL;
1531
1532         if (copy_from_user(&flags, arg, sizeof(flags)))
1533                 return -EFAULT;
1534
1535         if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1536                 return -EINVAL;
1537
1538         if (flags & ~BTRFS_SUBVOL_RDONLY)
1539                 return -EOPNOTSUPP;
1540
1541         if (!inode_owner_or_capable(inode))
1542                 return -EACCES;
1543
1544         down_write(&root->fs_info->subvol_sem);
1545
1546         /* nothing to do */
1547         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1548                 goto out;
1549
1550         root_flags = btrfs_root_flags(&root->root_item);
1551         if (flags & BTRFS_SUBVOL_RDONLY)
1552                 btrfs_set_root_flags(&root->root_item,
1553                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1554         else
1555                 btrfs_set_root_flags(&root->root_item,
1556                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1557
1558         trans = btrfs_start_transaction(root, 1);
1559         if (IS_ERR(trans)) {
1560                 ret = PTR_ERR(trans);
1561                 goto out_reset;
1562         }
1563
1564         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1565                                 &root->root_key, &root->root_item);
1566
1567         btrfs_commit_transaction(trans, root);
1568 out_reset:
1569         if (ret)
1570                 btrfs_set_root_flags(&root->root_item, root_flags);
1571 out:
1572         up_write(&root->fs_info->subvol_sem);
1573         return ret;
1574 }
1575
1576 /*
1577  * helper to check if the subvolume references other subvolumes
1578  */
1579 static noinline int may_destroy_subvol(struct btrfs_root *root)
1580 {
1581         struct btrfs_path *path;
1582         struct btrfs_key key;
1583         int ret;
1584
1585         path = btrfs_alloc_path();
1586         if (!path)
1587                 return -ENOMEM;
1588
1589         key.objectid = root->root_key.objectid;
1590         key.type = BTRFS_ROOT_REF_KEY;
1591         key.offset = (u64)-1;
1592
1593         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1594                                 &key, path, 0, 0);
1595         if (ret < 0)
1596                 goto out;
1597         BUG_ON(ret == 0);
1598
1599         ret = 0;
1600         if (path->slots[0] > 0) {
1601                 path->slots[0]--;
1602                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1603                 if (key.objectid == root->root_key.objectid &&
1604                     key.type == BTRFS_ROOT_REF_KEY)
1605                         ret = -ENOTEMPTY;
1606         }
1607 out:
1608         btrfs_free_path(path);
1609         return ret;
1610 }
1611
1612 static noinline int key_in_sk(struct btrfs_key *key,
1613                               struct btrfs_ioctl_search_key *sk)
1614 {
1615         struct btrfs_key test;
1616         int ret;
1617
1618         test.objectid = sk->min_objectid;
1619         test.type = sk->min_type;
1620         test.offset = sk->min_offset;
1621
1622         ret = btrfs_comp_cpu_keys(key, &test);
1623         if (ret < 0)
1624                 return 0;
1625
1626         test.objectid = sk->max_objectid;
1627         test.type = sk->max_type;
1628         test.offset = sk->max_offset;
1629
1630         ret = btrfs_comp_cpu_keys(key, &test);
1631         if (ret > 0)
1632                 return 0;
1633         return 1;
1634 }
1635
1636 static noinline int copy_to_sk(struct btrfs_root *root,
1637                                struct btrfs_path *path,
1638                                struct btrfs_key *key,
1639                                struct btrfs_ioctl_search_key *sk,
1640                                char *buf,
1641                                unsigned long *sk_offset,
1642                                int *num_found)
1643 {
1644         u64 found_transid;
1645         struct extent_buffer *leaf;
1646         struct btrfs_ioctl_search_header sh;
1647         unsigned long item_off;
1648         unsigned long item_len;
1649         int nritems;
1650         int i;
1651         int slot;
1652         int ret = 0;
1653
1654         leaf = path->nodes[0];
1655         slot = path->slots[0];
1656         nritems = btrfs_header_nritems(leaf);
1657
1658         if (btrfs_header_generation(leaf) > sk->max_transid) {
1659                 i = nritems;
1660                 goto advance_key;
1661         }
1662         found_transid = btrfs_header_generation(leaf);
1663
1664         for (i = slot; i < nritems; i++) {
1665                 item_off = btrfs_item_ptr_offset(leaf, i);
1666                 item_len = btrfs_item_size_nr(leaf, i);
1667
1668                 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1669                         item_len = 0;
1670
1671                 if (sizeof(sh) + item_len + *sk_offset >
1672                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1673                         ret = 1;
1674                         goto overflow;
1675                 }
1676
1677                 btrfs_item_key_to_cpu(leaf, key, i);
1678                 if (!key_in_sk(key, sk))
1679                         continue;
1680
1681                 sh.objectid = key->objectid;
1682                 sh.offset = key->offset;
1683                 sh.type = key->type;
1684                 sh.len = item_len;
1685                 sh.transid = found_transid;
1686
1687                 /* copy search result header */
1688                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1689                 *sk_offset += sizeof(sh);
1690
1691                 if (item_len) {
1692                         char *p = buf + *sk_offset;
1693                         /* copy the item */
1694                         read_extent_buffer(leaf, p,
1695                                            item_off, item_len);
1696                         *sk_offset += item_len;
1697                 }
1698                 (*num_found)++;
1699
1700                 if (*num_found >= sk->nr_items)
1701                         break;
1702         }
1703 advance_key:
1704         ret = 0;
1705         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1706                 key->offset++;
1707         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1708                 key->offset = 0;
1709                 key->type++;
1710         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1711                 key->offset = 0;
1712                 key->type = 0;
1713                 key->objectid++;
1714         } else
1715                 ret = 1;
1716 overflow:
1717         return ret;
1718 }
1719
1720 static noinline int search_ioctl(struct inode *inode,
1721                                  struct btrfs_ioctl_search_args *args)
1722 {
1723         struct btrfs_root *root;
1724         struct btrfs_key key;
1725         struct btrfs_key max_key;
1726         struct btrfs_path *path;
1727         struct btrfs_ioctl_search_key *sk = &args->key;
1728         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1729         int ret;
1730         int num_found = 0;
1731         unsigned long sk_offset = 0;
1732
1733         path = btrfs_alloc_path();
1734         if (!path)
1735                 return -ENOMEM;
1736
1737         if (sk->tree_id == 0) {
1738                 /* search the root of the inode that was passed */
1739                 root = BTRFS_I(inode)->root;
1740         } else {
1741                 key.objectid = sk->tree_id;
1742                 key.type = BTRFS_ROOT_ITEM_KEY;
1743                 key.offset = (u64)-1;
1744                 root = btrfs_read_fs_root_no_name(info, &key);
1745                 if (IS_ERR(root)) {
1746                         printk(KERN_ERR "could not find root %llu\n",
1747                                sk->tree_id);
1748                         btrfs_free_path(path);
1749                         return -ENOENT;
1750                 }
1751         }
1752
1753         key.objectid = sk->min_objectid;
1754         key.type = sk->min_type;
1755         key.offset = sk->min_offset;
1756
1757         max_key.objectid = sk->max_objectid;
1758         max_key.type = sk->max_type;
1759         max_key.offset = sk->max_offset;
1760
1761         path->keep_locks = 1;
1762
1763         while(1) {
1764                 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1765                                            sk->min_transid);
1766                 if (ret != 0) {
1767                         if (ret > 0)
1768                                 ret = 0;
1769                         goto err;
1770                 }
1771                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1772                                  &sk_offset, &num_found);
1773                 btrfs_release_path(path);
1774                 if (ret || num_found >= sk->nr_items)
1775                         break;
1776
1777         }
1778         ret = 0;
1779 err:
1780         sk->nr_items = num_found;
1781         btrfs_free_path(path);
1782         return ret;
1783 }
1784
1785 static noinline int btrfs_ioctl_tree_search(struct file *file,
1786                                            void __user *argp)
1787 {
1788          struct btrfs_ioctl_search_args *args;
1789          struct inode *inode;
1790          int ret;
1791
1792         if (!capable(CAP_SYS_ADMIN))
1793                 return -EPERM;
1794
1795         args = memdup_user(argp, sizeof(*args));
1796         if (IS_ERR(args))
1797                 return PTR_ERR(args);
1798
1799         inode = fdentry(file)->d_inode;
1800         ret = search_ioctl(inode, args);
1801         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1802                 ret = -EFAULT;
1803         kfree(args);
1804         return ret;
1805 }
1806
1807 /*
1808  * Search INODE_REFs to identify path name of 'dirid' directory
1809  * in a 'tree_id' tree. and sets path name to 'name'.
1810  */
1811 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1812                                 u64 tree_id, u64 dirid, char *name)
1813 {
1814         struct btrfs_root *root;
1815         struct btrfs_key key;
1816         char *ptr;
1817         int ret = -1;
1818         int slot;
1819         int len;
1820         int total_len = 0;
1821         struct btrfs_inode_ref *iref;
1822         struct extent_buffer *l;
1823         struct btrfs_path *path;
1824
1825         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1826                 name[0]='\0';
1827                 return 0;
1828         }
1829
1830         path = btrfs_alloc_path();
1831         if (!path)
1832                 return -ENOMEM;
1833
1834         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1835
1836         key.objectid = tree_id;
1837         key.type = BTRFS_ROOT_ITEM_KEY;
1838         key.offset = (u64)-1;
1839         root = btrfs_read_fs_root_no_name(info, &key);
1840         if (IS_ERR(root)) {
1841                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1842                 ret = -ENOENT;
1843                 goto out;
1844         }
1845
1846         key.objectid = dirid;
1847         key.type = BTRFS_INODE_REF_KEY;
1848         key.offset = (u64)-1;
1849
1850         while(1) {
1851                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1852                 if (ret < 0)
1853                         goto out;
1854
1855                 l = path->nodes[0];
1856                 slot = path->slots[0];
1857                 if (ret > 0 && slot > 0)
1858                         slot--;
1859                 btrfs_item_key_to_cpu(l, &key, slot);
1860
1861                 if (ret > 0 && (key.objectid != dirid ||
1862                                 key.type != BTRFS_INODE_REF_KEY)) {
1863                         ret = -ENOENT;
1864                         goto out;
1865                 }
1866
1867                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1868                 len = btrfs_inode_ref_name_len(l, iref);
1869                 ptr -= len + 1;
1870                 total_len += len + 1;
1871                 if (ptr < name)
1872                         goto out;
1873
1874                 *(ptr + len) = '/';
1875                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1876
1877                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1878                         break;
1879
1880                 btrfs_release_path(path);
1881                 key.objectid = key.offset;
1882                 key.offset = (u64)-1;
1883                 dirid = key.objectid;
1884         }
1885         if (ptr < name)
1886                 goto out;
1887         memmove(name, ptr, total_len);
1888         name[total_len]='\0';
1889         ret = 0;
1890 out:
1891         btrfs_free_path(path);
1892         return ret;
1893 }
1894
1895 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1896                                            void __user *argp)
1897 {
1898          struct btrfs_ioctl_ino_lookup_args *args;
1899          struct inode *inode;
1900          int ret;
1901
1902         if (!capable(CAP_SYS_ADMIN))
1903                 return -EPERM;
1904
1905         args = memdup_user(argp, sizeof(*args));
1906         if (IS_ERR(args))
1907                 return PTR_ERR(args);
1908
1909         inode = fdentry(file)->d_inode;
1910
1911         if (args->treeid == 0)
1912                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1913
1914         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1915                                         args->treeid, args->objectid,
1916                                         args->name);
1917
1918         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1919                 ret = -EFAULT;
1920
1921         kfree(args);
1922         return ret;
1923 }
1924
1925 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1926                                              void __user *arg)
1927 {
1928         struct dentry *parent = fdentry(file);
1929         struct dentry *dentry;
1930         struct inode *dir = parent->d_inode;
1931         struct inode *inode;
1932         struct btrfs_root *root = BTRFS_I(dir)->root;
1933         struct btrfs_root *dest = NULL;
1934         struct btrfs_ioctl_vol_args *vol_args;
1935         struct btrfs_trans_handle *trans;
1936         int namelen;
1937         int ret;
1938         int err = 0;
1939
1940         vol_args = memdup_user(arg, sizeof(*vol_args));
1941         if (IS_ERR(vol_args))
1942                 return PTR_ERR(vol_args);
1943
1944         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1945         namelen = strlen(vol_args->name);
1946         if (strchr(vol_args->name, '/') ||
1947             strncmp(vol_args->name, "..", namelen) == 0) {
1948                 err = -EINVAL;
1949                 goto out;
1950         }
1951
1952         err = mnt_want_write_file(file);
1953         if (err)
1954                 goto out;
1955
1956         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1957         dentry = lookup_one_len(vol_args->name, parent, namelen);
1958         if (IS_ERR(dentry)) {
1959                 err = PTR_ERR(dentry);
1960                 goto out_unlock_dir;
1961         }
1962
1963         if (!dentry->d_inode) {
1964                 err = -ENOENT;
1965                 goto out_dput;
1966         }
1967
1968         inode = dentry->d_inode;
1969         dest = BTRFS_I(inode)->root;
1970         if (!capable(CAP_SYS_ADMIN)){
1971                 /*
1972                  * Regular user.  Only allow this with a special mount
1973                  * option, when the user has write+exec access to the
1974                  * subvol root, and when rmdir(2) would have been
1975                  * allowed.
1976                  *
1977                  * Note that this is _not_ check that the subvol is
1978                  * empty or doesn't contain data that we wouldn't
1979                  * otherwise be able to delete.
1980                  *
1981                  * Users who want to delete empty subvols should try
1982                  * rmdir(2).
1983                  */
1984                 err = -EPERM;
1985                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1986                         goto out_dput;
1987
1988                 /*
1989                  * Do not allow deletion if the parent dir is the same
1990                  * as the dir to be deleted.  That means the ioctl
1991                  * must be called on the dentry referencing the root
1992                  * of the subvol, not a random directory contained
1993                  * within it.
1994                  */
1995                 err = -EINVAL;
1996                 if (root == dest)
1997                         goto out_dput;
1998
1999                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2000                 if (err)
2001                         goto out_dput;
2002
2003                 /* check if subvolume may be deleted by a non-root user */
2004                 err = btrfs_may_delete(dir, dentry, 1);
2005                 if (err)
2006                         goto out_dput;
2007         }
2008
2009         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2010                 err = -EINVAL;
2011                 goto out_dput;
2012         }
2013
2014         mutex_lock(&inode->i_mutex);
2015         err = d_invalidate(dentry);
2016         if (err)
2017                 goto out_unlock;
2018
2019         down_write(&root->fs_info->subvol_sem);
2020
2021         err = may_destroy_subvol(dest);
2022         if (err)
2023                 goto out_up_write;
2024
2025         trans = btrfs_start_transaction(root, 0);
2026         if (IS_ERR(trans)) {
2027                 err = PTR_ERR(trans);
2028                 goto out_up_write;
2029         }
2030         trans->block_rsv = &root->fs_info->global_block_rsv;
2031
2032         ret = btrfs_unlink_subvol(trans, root, dir,
2033                                 dest->root_key.objectid,
2034                                 dentry->d_name.name,
2035                                 dentry->d_name.len);
2036         if (ret) {
2037                 err = ret;
2038                 btrfs_abort_transaction(trans, root, ret);
2039                 goto out_end_trans;
2040         }
2041
2042         btrfs_record_root_in_trans(trans, dest);
2043
2044         memset(&dest->root_item.drop_progress, 0,
2045                 sizeof(dest->root_item.drop_progress));
2046         dest->root_item.drop_level = 0;
2047         btrfs_set_root_refs(&dest->root_item, 0);
2048
2049         if (!xchg(&dest->orphan_item_inserted, 1)) {
2050                 ret = btrfs_insert_orphan_item(trans,
2051                                         root->fs_info->tree_root,
2052                                         dest->root_key.objectid);
2053                 if (ret) {
2054                         btrfs_abort_transaction(trans, root, ret);
2055                         err = ret;
2056                         goto out_end_trans;
2057                 }
2058         }
2059 out_end_trans:
2060         ret = btrfs_end_transaction(trans, root);
2061         if (ret && !err)
2062                 err = ret;
2063         inode->i_flags |= S_DEAD;
2064 out_up_write:
2065         up_write(&root->fs_info->subvol_sem);
2066 out_unlock:
2067         mutex_unlock(&inode->i_mutex);
2068         if (!err) {
2069                 shrink_dcache_sb(root->fs_info->sb);
2070                 btrfs_invalidate_inodes(dest);
2071                 d_delete(dentry);
2072         }
2073 out_dput:
2074         dput(dentry);
2075 out_unlock_dir:
2076         mutex_unlock(&dir->i_mutex);
2077         mnt_drop_write_file(file);
2078 out:
2079         kfree(vol_args);
2080         return err;
2081 }
2082
2083 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2084 {
2085         struct inode *inode = fdentry(file)->d_inode;
2086         struct btrfs_root *root = BTRFS_I(inode)->root;
2087         struct btrfs_ioctl_defrag_range_args *range;
2088         int ret;
2089
2090         if (btrfs_root_readonly(root))
2091                 return -EROFS;
2092
2093         ret = mnt_want_write_file(file);
2094         if (ret)
2095                 return ret;
2096
2097         switch (inode->i_mode & S_IFMT) {
2098         case S_IFDIR:
2099                 if (!capable(CAP_SYS_ADMIN)) {
2100                         ret = -EPERM;
2101                         goto out;
2102                 }
2103                 ret = btrfs_defrag_root(root, 0);
2104                 if (ret)
2105                         goto out;
2106                 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2107                 break;
2108         case S_IFREG:
2109                 if (!(file->f_mode & FMODE_WRITE)) {
2110                         ret = -EINVAL;
2111                         goto out;
2112                 }
2113
2114                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2115                 if (!range) {
2116                         ret = -ENOMEM;
2117                         goto out;
2118                 }
2119
2120                 if (argp) {
2121                         if (copy_from_user(range, argp,
2122                                            sizeof(*range))) {
2123                                 ret = -EFAULT;
2124                                 kfree(range);
2125                                 goto out;
2126                         }
2127                         /* compression requires us to start the IO */
2128                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2129                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2130                                 range->extent_thresh = (u32)-1;
2131                         }
2132                 } else {
2133                         /* the rest are all set to zero by kzalloc */
2134                         range->len = (u64)-1;
2135                 }
2136                 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2137                                         range, 0, 0);
2138                 if (ret > 0)
2139                         ret = 0;
2140                 kfree(range);
2141                 break;
2142         default:
2143                 ret = -EINVAL;
2144         }
2145 out:
2146         mnt_drop_write_file(file);
2147         return ret;
2148 }
2149
2150 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2151 {
2152         struct btrfs_ioctl_vol_args *vol_args;
2153         int ret;
2154
2155         if (!capable(CAP_SYS_ADMIN))
2156                 return -EPERM;
2157
2158         mutex_lock(&root->fs_info->volume_mutex);
2159         if (root->fs_info->balance_ctl) {
2160                 printk(KERN_INFO "btrfs: balance in progress\n");
2161                 ret = -EINVAL;
2162                 goto out;
2163         }
2164
2165         vol_args = memdup_user(arg, sizeof(*vol_args));
2166         if (IS_ERR(vol_args)) {
2167                 ret = PTR_ERR(vol_args);
2168                 goto out;
2169         }
2170
2171         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2172         ret = btrfs_init_new_device(root, vol_args->name);
2173
2174         kfree(vol_args);
2175 out:
2176         mutex_unlock(&root->fs_info->volume_mutex);
2177         return ret;
2178 }
2179
2180 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2181 {
2182         struct btrfs_ioctl_vol_args *vol_args;
2183         int ret;
2184
2185         if (!capable(CAP_SYS_ADMIN))
2186                 return -EPERM;
2187
2188         if (root->fs_info->sb->s_flags & MS_RDONLY)
2189                 return -EROFS;
2190
2191         mutex_lock(&root->fs_info->volume_mutex);
2192         if (root->fs_info->balance_ctl) {
2193                 printk(KERN_INFO "btrfs: balance in progress\n");
2194                 ret = -EINVAL;
2195                 goto out;
2196         }
2197
2198         vol_args = memdup_user(arg, sizeof(*vol_args));
2199         if (IS_ERR(vol_args)) {
2200                 ret = PTR_ERR(vol_args);
2201                 goto out;
2202         }
2203
2204         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2205         ret = btrfs_rm_device(root, vol_args->name);
2206
2207         kfree(vol_args);
2208 out:
2209         mutex_unlock(&root->fs_info->volume_mutex);
2210         return ret;
2211 }
2212
2213 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2214 {
2215         struct btrfs_ioctl_fs_info_args *fi_args;
2216         struct btrfs_device *device;
2217         struct btrfs_device *next;
2218         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2219         int ret = 0;
2220
2221         if (!capable(CAP_SYS_ADMIN))
2222                 return -EPERM;
2223
2224         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2225         if (!fi_args)
2226                 return -ENOMEM;
2227
2228         fi_args->num_devices = fs_devices->num_devices;
2229         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2230
2231         mutex_lock(&fs_devices->device_list_mutex);
2232         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2233                 if (device->devid > fi_args->max_id)
2234                         fi_args->max_id = device->devid;
2235         }
2236         mutex_unlock(&fs_devices->device_list_mutex);
2237
2238         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2239                 ret = -EFAULT;
2240
2241         kfree(fi_args);
2242         return ret;
2243 }
2244
2245 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2246 {
2247         struct btrfs_ioctl_dev_info_args *di_args;
2248         struct btrfs_device *dev;
2249         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2250         int ret = 0;
2251         char *s_uuid = NULL;
2252         char empty_uuid[BTRFS_UUID_SIZE] = {0};
2253
2254         if (!capable(CAP_SYS_ADMIN))
2255                 return -EPERM;
2256
2257         di_args = memdup_user(arg, sizeof(*di_args));
2258         if (IS_ERR(di_args))
2259                 return PTR_ERR(di_args);
2260
2261         if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2262                 s_uuid = di_args->uuid;
2263
2264         mutex_lock(&fs_devices->device_list_mutex);
2265         dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2266         mutex_unlock(&fs_devices->device_list_mutex);
2267
2268         if (!dev) {
2269                 ret = -ENODEV;
2270                 goto out;
2271         }
2272
2273         di_args->devid = dev->devid;
2274         di_args->bytes_used = dev->bytes_used;
2275         di_args->total_bytes = dev->total_bytes;
2276         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2277         if (dev->name) {
2278                 struct rcu_string *name;
2279
2280                 rcu_read_lock();
2281                 name = rcu_dereference(dev->name);
2282                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2283                 rcu_read_unlock();
2284                 di_args->path[sizeof(di_args->path) - 1] = 0;
2285         } else {
2286                 di_args->path[0] = '\0';
2287         }
2288
2289 out:
2290         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2291                 ret = -EFAULT;
2292
2293         kfree(di_args);
2294         return ret;
2295 }
2296
2297 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2298                                        u64 off, u64 olen, u64 destoff)
2299 {
2300         struct inode *inode = fdentry(file)->d_inode;
2301         struct btrfs_root *root = BTRFS_I(inode)->root;
2302         struct file *src_file;
2303         struct inode *src;
2304         struct btrfs_trans_handle *trans;
2305         struct btrfs_path *path;
2306         struct extent_buffer *leaf;
2307         char *buf;
2308         struct btrfs_key key;
2309         u32 nritems;
2310         int slot;
2311         int ret;
2312         u64 len = olen;
2313         u64 bs = root->fs_info->sb->s_blocksize;
2314         u64 hint_byte;
2315
2316         /*
2317          * TODO:
2318          * - split compressed inline extents.  annoying: we need to
2319          *   decompress into destination's address_space (the file offset
2320          *   may change, so source mapping won't do), then recompress (or
2321          *   otherwise reinsert) a subrange.
2322          * - allow ranges within the same file to be cloned (provided
2323          *   they don't overlap)?
2324          */
2325
2326         /* the destination must be opened for writing */
2327         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2328                 return -EINVAL;
2329
2330         if (btrfs_root_readonly(root))
2331                 return -EROFS;
2332
2333         ret = mnt_want_write_file(file);
2334         if (ret)
2335                 return ret;
2336
2337         src_file = fget(srcfd);
2338         if (!src_file) {
2339                 ret = -EBADF;
2340                 goto out_drop_write;
2341         }
2342
2343         src = src_file->f_dentry->d_inode;
2344
2345         ret = -EINVAL;
2346         if (src == inode)
2347                 goto out_fput;
2348
2349         /* the src must be open for reading */
2350         if (!(src_file->f_mode & FMODE_READ))
2351                 goto out_fput;
2352
2353         /* don't make the dst file partly checksummed */
2354         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2355             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2356                 goto out_fput;
2357
2358         ret = -EISDIR;
2359         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2360                 goto out_fput;
2361
2362         ret = -EXDEV;
2363         if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
2364                 goto out_fput;
2365
2366         ret = -ENOMEM;
2367         buf = vmalloc(btrfs_level_size(root, 0));
2368         if (!buf)
2369                 goto out_fput;
2370
2371         path = btrfs_alloc_path();
2372         if (!path) {
2373                 vfree(buf);
2374                 goto out_fput;
2375         }
2376         path->reada = 2;
2377
2378         if (inode < src) {
2379                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2380                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2381         } else {
2382                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2383                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2384         }
2385
2386         /* determine range to clone */
2387         ret = -EINVAL;
2388         if (off + len > src->i_size || off + len < off)
2389                 goto out_unlock;
2390         if (len == 0)
2391                 olen = len = src->i_size - off;
2392         /* if we extend to eof, continue to block boundary */
2393         if (off + len == src->i_size)
2394                 len = ALIGN(src->i_size, bs) - off;
2395
2396         /* verify the end result is block aligned */
2397         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2398             !IS_ALIGNED(destoff, bs))
2399                 goto out_unlock;
2400
2401         if (destoff > inode->i_size) {
2402                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2403                 if (ret)
2404                         goto out_unlock;
2405         }
2406
2407         /* truncate page cache pages from target inode range */
2408         truncate_inode_pages_range(&inode->i_data, destoff,
2409                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
2410
2411         /* do any pending delalloc/csum calc on src, one way or
2412            another, and lock file content */
2413         while (1) {
2414                 struct btrfs_ordered_extent *ordered;
2415                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2416                 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2417                 if (!ordered &&
2418                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2419                                    EXTENT_DELALLOC, 0, NULL))
2420                         break;
2421                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2422                 if (ordered)
2423                         btrfs_put_ordered_extent(ordered);
2424                 btrfs_wait_ordered_range(src, off, len);
2425         }
2426
2427         /* clone data */
2428         key.objectid = btrfs_ino(src);
2429         key.type = BTRFS_EXTENT_DATA_KEY;
2430         key.offset = 0;
2431
2432         while (1) {
2433                 /*
2434                  * note the key will change type as we walk through the
2435                  * tree.
2436                  */
2437                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2438                 if (ret < 0)
2439                         goto out;
2440
2441                 nritems = btrfs_header_nritems(path->nodes[0]);
2442                 if (path->slots[0] >= nritems) {
2443                         ret = btrfs_next_leaf(root, path);
2444                         if (ret < 0)
2445                                 goto out;
2446                         if (ret > 0)
2447                                 break;
2448                         nritems = btrfs_header_nritems(path->nodes[0]);
2449                 }
2450                 leaf = path->nodes[0];
2451                 slot = path->slots[0];
2452
2453                 btrfs_item_key_to_cpu(leaf, &key, slot);
2454                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2455                     key.objectid != btrfs_ino(src))
2456                         break;
2457
2458                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2459                         struct btrfs_file_extent_item *extent;
2460                         int type;
2461                         u32 size;
2462                         struct btrfs_key new_key;
2463                         u64 disko = 0, diskl = 0;
2464                         u64 datao = 0, datal = 0;
2465                         u8 comp;
2466                         u64 endoff;
2467
2468                         size = btrfs_item_size_nr(leaf, slot);
2469                         read_extent_buffer(leaf, buf,
2470                                            btrfs_item_ptr_offset(leaf, slot),
2471                                            size);
2472
2473                         extent = btrfs_item_ptr(leaf, slot,
2474                                                 struct btrfs_file_extent_item);
2475                         comp = btrfs_file_extent_compression(leaf, extent);
2476                         type = btrfs_file_extent_type(leaf, extent);
2477                         if (type == BTRFS_FILE_EXTENT_REG ||
2478                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2479                                 disko = btrfs_file_extent_disk_bytenr(leaf,
2480                                                                       extent);
2481                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2482                                                                  extent);
2483                                 datao = btrfs_file_extent_offset(leaf, extent);
2484                                 datal = btrfs_file_extent_num_bytes(leaf,
2485                                                                     extent);
2486                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2487                                 /* take upper bound, may be compressed */
2488                                 datal = btrfs_file_extent_ram_bytes(leaf,
2489                                                                     extent);
2490                         }
2491                         btrfs_release_path(path);
2492
2493                         if (key.offset + datal <= off ||
2494                             key.offset >= off+len)
2495                                 goto next;
2496
2497                         memcpy(&new_key, &key, sizeof(new_key));
2498                         new_key.objectid = btrfs_ino(inode);
2499                         if (off <= key.offset)
2500                                 new_key.offset = key.offset + destoff - off;
2501                         else
2502                                 new_key.offset = destoff;
2503
2504                         /*
2505                          * 1 - adjusting old extent (we may have to split it)
2506                          * 1 - add new extent
2507                          * 1 - inode update
2508                          */
2509                         trans = btrfs_start_transaction(root, 3);
2510                         if (IS_ERR(trans)) {
2511                                 ret = PTR_ERR(trans);
2512                                 goto out;
2513                         }
2514
2515                         if (type == BTRFS_FILE_EXTENT_REG ||
2516                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2517                                 /*
2518                                  *    a  | --- range to clone ---|  b
2519                                  * | ------------- extent ------------- |
2520                                  */
2521
2522                                 /* substract range b */
2523                                 if (key.offset + datal > off + len)
2524                                         datal = off + len - key.offset;
2525
2526                                 /* substract range a */
2527                                 if (off > key.offset) {
2528                                         datao += off - key.offset;
2529                                         datal -= off - key.offset;
2530                                 }
2531
2532                                 ret = btrfs_drop_extents(trans, inode,
2533                                                          new_key.offset,
2534                                                          new_key.offset + datal,
2535                                                          &hint_byte, 1);
2536                                 if (ret) {
2537                                         btrfs_abort_transaction(trans, root,
2538                                                                 ret);
2539                                         btrfs_end_transaction(trans, root);
2540                                         goto out;
2541                                 }
2542
2543                                 ret = btrfs_insert_empty_item(trans, root, path,
2544                                                               &new_key, size);
2545                                 if (ret) {
2546                                         btrfs_abort_transaction(trans, root,
2547                                                                 ret);
2548                                         btrfs_end_transaction(trans, root);
2549                                         goto out;
2550                                 }
2551
2552                                 leaf = path->nodes[0];
2553                                 slot = path->slots[0];
2554                                 write_extent_buffer(leaf, buf,
2555                                             btrfs_item_ptr_offset(leaf, slot),
2556                                             size);
2557
2558                                 extent = btrfs_item_ptr(leaf, slot,
2559                                                 struct btrfs_file_extent_item);
2560
2561                                 /* disko == 0 means it's a hole */
2562                                 if (!disko)
2563                                         datao = 0;
2564
2565                                 btrfs_set_file_extent_offset(leaf, extent,
2566                                                              datao);
2567                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2568                                                                 datal);
2569                                 if (disko) {
2570                                         inode_add_bytes(inode, datal);
2571                                         ret = btrfs_inc_extent_ref(trans, root,
2572                                                         disko, diskl, 0,
2573                                                         root->root_key.objectid,
2574                                                         btrfs_ino(inode),
2575                                                         new_key.offset - datao,
2576                                                         0);
2577                                         if (ret) {
2578                                                 btrfs_abort_transaction(trans,
2579                                                                         root,
2580                                                                         ret);
2581                                                 btrfs_end_transaction(trans,
2582                                                                       root);
2583                                                 goto out;
2584
2585                                         }
2586                                 }
2587                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2588                                 u64 skip = 0;
2589                                 u64 trim = 0;
2590                                 if (off > key.offset) {
2591                                         skip = off - key.offset;
2592                                         new_key.offset += skip;
2593                                 }
2594
2595                                 if (key.offset + datal > off+len)
2596                                         trim = key.offset + datal - (off+len);
2597
2598                                 if (comp && (skip || trim)) {
2599                                         ret = -EINVAL;
2600                                         btrfs_end_transaction(trans, root);
2601                                         goto out;
2602                                 }
2603                                 size -= skip + trim;
2604                                 datal -= skip + trim;
2605
2606                                 ret = btrfs_drop_extents(trans, inode,
2607                                                          new_key.offset,
2608                                                          new_key.offset + datal,
2609                                                          &hint_byte, 1);
2610                                 if (ret) {
2611                                         btrfs_abort_transaction(trans, root,
2612                                                                 ret);
2613                                         btrfs_end_transaction(trans, root);
2614                                         goto out;
2615                                 }
2616
2617                                 ret = btrfs_insert_empty_item(trans, root, path,
2618                                                               &new_key, size);
2619                                 if (ret) {
2620                                         btrfs_abort_transaction(trans, root,
2621                                                                 ret);
2622                                         btrfs_end_transaction(trans, root);
2623                                         goto out;
2624                                 }
2625
2626                                 if (skip) {
2627                                         u32 start =
2628                                           btrfs_file_extent_calc_inline_size(0);
2629                                         memmove(buf+start, buf+start+skip,
2630                                                 datal);
2631                                 }
2632
2633                                 leaf = path->nodes[0];
2634                                 slot = path->slots[0];
2635                                 write_extent_buffer(leaf, buf,
2636                                             btrfs_item_ptr_offset(leaf, slot),
2637                                             size);
2638                                 inode_add_bytes(inode, datal);
2639                         }
2640
2641                         btrfs_mark_buffer_dirty(leaf);
2642                         btrfs_release_path(path);
2643
2644                         inode_inc_iversion(inode);
2645                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2646
2647                         /*
2648                          * we round up to the block size at eof when
2649                          * determining which extents to clone above,
2650                          * but shouldn't round up the file size
2651                          */
2652                         endoff = new_key.offset + datal;
2653                         if (endoff > destoff+olen)
2654                                 endoff = destoff+olen;
2655                         if (endoff > inode->i_size)
2656                                 btrfs_i_size_write(inode, endoff);
2657
2658                         ret = btrfs_update_inode(trans, root, inode);
2659                         if (ret) {
2660                                 btrfs_abort_transaction(trans, root, ret);
2661                                 btrfs_end_transaction(trans, root);
2662                                 goto out;
2663                         }
2664                         ret = btrfs_end_transaction(trans, root);
2665                 }
2666 next:
2667                 btrfs_release_path(path);
2668                 key.offset++;
2669         }
2670         ret = 0;
2671 out:
2672         btrfs_release_path(path);
2673         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2674 out_unlock:
2675         mutex_unlock(&src->i_mutex);
2676         mutex_unlock(&inode->i_mutex);
2677         vfree(buf);
2678         btrfs_free_path(path);
2679 out_fput:
2680         fput(src_file);
2681 out_drop_write:
2682         mnt_drop_write_file(file);
2683         return ret;
2684 }
2685
2686 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2687 {
2688         struct btrfs_ioctl_clone_range_args args;
2689
2690         if (copy_from_user(&args, argp, sizeof(args)))
2691                 return -EFAULT;
2692         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2693                                  args.src_length, args.dest_offset);
2694 }
2695
2696 /*
2697  * there are many ways the trans_start and trans_end ioctls can lead
2698  * to deadlocks.  They should only be used by applications that
2699  * basically own the machine, and have a very in depth understanding
2700  * of all the possible deadlocks and enospc problems.
2701  */
2702 static long btrfs_ioctl_trans_start(struct file *file)
2703 {
2704         struct inode *inode = fdentry(file)->d_inode;
2705         struct btrfs_root *root = BTRFS_I(inode)->root;
2706         struct btrfs_trans_handle *trans;
2707         int ret;
2708
2709         ret = -EPERM;
2710         if (!capable(CAP_SYS_ADMIN))
2711                 goto out;
2712
2713         ret = -EINPROGRESS;
2714         if (file->private_data)
2715                 goto out;
2716
2717         ret = -EROFS;
2718         if (btrfs_root_readonly(root))
2719                 goto out;
2720
2721         ret = mnt_want_write_file(file);
2722         if (ret)
2723                 goto out;
2724
2725         atomic_inc(&root->fs_info->open_ioctl_trans);
2726
2727         ret = -ENOMEM;
2728         trans = btrfs_start_ioctl_transaction(root);
2729         if (IS_ERR(trans))
2730                 goto out_drop;
2731
2732         file->private_data = trans;
2733         return 0;
2734
2735 out_drop:
2736         atomic_dec(&root->fs_info->open_ioctl_trans);
2737         mnt_drop_write_file(file);
2738 out:
2739         return ret;
2740 }
2741
2742 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2743 {
2744         struct inode *inode = fdentry(file)->d_inode;
2745         struct btrfs_root *root = BTRFS_I(inode)->root;
2746         struct btrfs_root *new_root;
2747         struct btrfs_dir_item *di;
2748         struct btrfs_trans_handle *trans;
2749         struct btrfs_path *path;
2750         struct btrfs_key location;
2751         struct btrfs_disk_key disk_key;
2752         struct btrfs_super_block *disk_super;
2753         u64 features;
2754         u64 objectid = 0;
2755         u64 dir_id;
2756
2757         if (!capable(CAP_SYS_ADMIN))
2758                 return -EPERM;
2759
2760         if (copy_from_user(&objectid, argp, sizeof(objectid)))
2761                 return -EFAULT;
2762
2763         if (!objectid)
2764                 objectid = root->root_key.objectid;
2765
2766         location.objectid = objectid;
2767         location.type = BTRFS_ROOT_ITEM_KEY;
2768         location.offset = (u64)-1;
2769
2770         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2771         if (IS_ERR(new_root))
2772                 return PTR_ERR(new_root);
2773
2774         if (btrfs_root_refs(&new_root->root_item) == 0)
2775                 return -ENOENT;
2776
2777         path = btrfs_alloc_path();
2778         if (!path)
2779                 return -ENOMEM;
2780         path->leave_spinning = 1;
2781
2782         trans = btrfs_start_transaction(root, 1);
2783         if (IS_ERR(trans)) {
2784                 btrfs_free_path(path);
2785                 return PTR_ERR(trans);
2786         }
2787
2788         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2789         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2790                                    dir_id, "default", 7, 1);
2791         if (IS_ERR_OR_NULL(di)) {
2792                 btrfs_free_path(path);
2793                 btrfs_end_transaction(trans, root);
2794                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2795                        "this isn't going to work\n");
2796                 return -ENOENT;
2797         }
2798
2799         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2800         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2801         btrfs_mark_buffer_dirty(path->nodes[0]);
2802         btrfs_free_path(path);
2803
2804         disk_super = root->fs_info->super_copy;
2805         features = btrfs_super_incompat_flags(disk_super);
2806         if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2807                 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2808                 btrfs_set_super_incompat_flags(disk_super, features);
2809         }
2810         btrfs_end_transaction(trans, root);
2811
2812         return 0;
2813 }
2814
2815 static void get_block_group_info(struct list_head *groups_list,
2816                                  struct btrfs_ioctl_space_info *space)
2817 {
2818         struct btrfs_block_group_cache *block_group;
2819
2820         space->total_bytes = 0;
2821         space->used_bytes = 0;
2822         space->flags = 0;
2823         list_for_each_entry(block_group, groups_list, list) {
2824                 space->flags = block_group->flags;
2825                 space->total_bytes += block_group->key.offset;
2826                 space->used_bytes +=
2827                         btrfs_block_group_used(&block_group->item);
2828         }
2829 }
2830
2831 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2832 {
2833         struct btrfs_ioctl_space_args space_args;
2834         struct btrfs_ioctl_space_info space;
2835         struct btrfs_ioctl_space_info *dest;
2836         struct btrfs_ioctl_space_info *dest_orig;
2837         struct btrfs_ioctl_space_info __user *user_dest;
2838         struct btrfs_space_info *info;
2839         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2840                        BTRFS_BLOCK_GROUP_SYSTEM,
2841                        BTRFS_BLOCK_GROUP_METADATA,
2842                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2843         int num_types = 4;
2844         int alloc_size;
2845         int ret = 0;
2846         u64 slot_count = 0;
2847         int i, c;
2848
2849         if (copy_from_user(&space_args,
2850                            (struct btrfs_ioctl_space_args __user *)arg,
2851                            sizeof(space_args)))
2852                 return -EFAULT;
2853
2854         for (i = 0; i < num_types; i++) {
2855                 struct btrfs_space_info *tmp;
2856
2857                 info = NULL;
2858                 rcu_read_lock();
2859                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2860                                         list) {
2861                         if (tmp->flags == types[i]) {
2862                                 info = tmp;
2863                                 break;
2864                         }
2865                 }
2866                 rcu_read_unlock();
2867
2868                 if (!info)
2869                         continue;
2870
2871                 down_read(&info->groups_sem);
2872                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2873                         if (!list_empty(&info->block_groups[c]))
2874                                 slot_count++;
2875                 }
2876                 up_read(&info->groups_sem);
2877         }
2878
2879         /* space_slots == 0 means they are asking for a count */
2880         if (space_args.space_slots == 0) {
2881                 space_args.total_spaces = slot_count;
2882                 goto out;
2883         }
2884
2885         slot_count = min_t(u64, space_args.space_slots, slot_count);
2886
2887         alloc_size = sizeof(*dest) * slot_count;
2888
2889         /* we generally have at most 6 or so space infos, one for each raid
2890          * level.  So, a whole page should be more than enough for everyone
2891          */
2892         if (alloc_size > PAGE_CACHE_SIZE)
2893                 return -ENOMEM;
2894
2895         space_args.total_spaces = 0;
2896         dest = kmalloc(alloc_size, GFP_NOFS);
2897         if (!dest)
2898                 return -ENOMEM;
2899         dest_orig = dest;
2900
2901         /* now we have a buffer to copy into */
2902         for (i = 0; i < num_types; i++) {
2903                 struct btrfs_space_info *tmp;
2904
2905                 if (!slot_count)
2906                         break;
2907
2908                 info = NULL;
2909                 rcu_read_lock();
2910                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2911                                         list) {
2912                         if (tmp->flags == types[i]) {
2913                                 info = tmp;
2914                                 break;
2915                         }
2916                 }
2917                 rcu_read_unlock();
2918
2919                 if (!info)
2920                         continue;
2921                 down_read(&info->groups_sem);
2922                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2923                         if (!list_empty(&info->block_groups[c])) {
2924                                 get_block_group_info(&info->block_groups[c],
2925                                                      &space);
2926                                 memcpy(dest, &space, sizeof(space));
2927                                 dest++;
2928                                 space_args.total_spaces++;
2929                                 slot_count--;
2930                         }
2931                         if (!slot_count)
2932                                 break;
2933                 }
2934                 up_read(&info->groups_sem);
2935         }
2936
2937         user_dest = (struct btrfs_ioctl_space_info __user *)
2938                 (arg + sizeof(struct btrfs_ioctl_space_args));
2939
2940         if (copy_to_user(user_dest, dest_orig, alloc_size))
2941                 ret = -EFAULT;
2942
2943         kfree(dest_orig);
2944 out:
2945         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2946                 ret = -EFAULT;
2947
2948         return ret;
2949 }
2950
2951 /*
2952  * there are many ways the trans_start and trans_end ioctls can lead
2953  * to deadlocks.  They should only be used by applications that
2954  * basically own the machine, and have a very in depth understanding
2955  * of all the possible deadlocks and enospc problems.
2956  */
2957 long btrfs_ioctl_trans_end(struct file *file)
2958 {
2959         struct inode *inode = fdentry(file)->d_inode;
2960         struct btrfs_root *root = BTRFS_I(inode)->root;
2961         struct btrfs_trans_handle *trans;
2962
2963         trans = file->private_data;
2964         if (!trans)
2965                 return -EINVAL;
2966         file->private_data = NULL;
2967
2968         btrfs_end_transaction(trans, root);
2969
2970         atomic_dec(&root->fs_info->open_ioctl_trans);
2971
2972         mnt_drop_write_file(file);
2973         return 0;
2974 }
2975
2976 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2977 {
2978         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2979         struct btrfs_trans_handle *trans;
2980         u64 transid;
2981         int ret;
2982
2983         trans = btrfs_start_transaction(root, 0);
2984         if (IS_ERR(trans))
2985                 return PTR_ERR(trans);
2986         transid = trans->transid;
2987         ret = btrfs_commit_transaction_async(trans, root, 0);
2988         if (ret) {
2989                 btrfs_end_transaction(trans, root);
2990                 return ret;
2991         }
2992
2993         if (argp)
2994                 if (copy_to_user(argp, &transid, sizeof(transid)))
2995                         return -EFAULT;
2996         return 0;
2997 }
2998
2999 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
3000 {
3001         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
3002         u64 transid;
3003
3004         if (argp) {
3005                 if (copy_from_user(&transid, argp, sizeof(transid)))
3006                         return -EFAULT;
3007         } else {
3008                 transid = 0;  /* current trans */
3009         }
3010         return btrfs_wait_for_commit(root, transid);
3011 }
3012
3013 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
3014 {
3015         int ret;
3016         struct btrfs_ioctl_scrub_args *sa;
3017
3018         if (!capable(CAP_SYS_ADMIN))
3019                 return -EPERM;
3020
3021         sa = memdup_user(arg, sizeof(*sa));
3022         if (IS_ERR(sa))
3023                 return PTR_ERR(sa);
3024
3025         ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
3026                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
3027
3028         if (copy_to_user(arg, sa, sizeof(*sa)))
3029                 ret = -EFAULT;
3030
3031         kfree(sa);
3032         return ret;
3033 }
3034
3035 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3036 {
3037         if (!capable(CAP_SYS_ADMIN))
3038                 return -EPERM;
3039
3040         return btrfs_scrub_cancel(root);
3041 }
3042
3043 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3044                                        void __user *arg)
3045 {
3046         struct btrfs_ioctl_scrub_args *sa;
3047         int ret;
3048
3049         if (!capable(CAP_SYS_ADMIN))
3050                 return -EPERM;
3051
3052         sa = memdup_user(arg, sizeof(*sa));
3053         if (IS_ERR(sa))
3054                 return PTR_ERR(sa);
3055
3056         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3057
3058         if (copy_to_user(arg, sa, sizeof(*sa)))
3059                 ret = -EFAULT;
3060
3061         kfree(sa);
3062         return ret;
3063 }
3064
3065 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3066                                       void __user *arg, int reset_after_read)
3067 {
3068         struct btrfs_ioctl_get_dev_stats *sa;
3069         int ret;
3070
3071         if (reset_after_read && !capable(CAP_SYS_ADMIN))
3072                 return -EPERM;
3073
3074         sa = memdup_user(arg, sizeof(*sa));
3075         if (IS_ERR(sa))
3076                 return PTR_ERR(sa);
3077
3078         ret = btrfs_get_dev_stats(root, sa, reset_after_read);
3079
3080         if (copy_to_user(arg, sa, sizeof(*sa)))
3081                 ret = -EFAULT;
3082
3083         kfree(sa);
3084         return ret;
3085 }
3086
3087 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3088 {
3089         int ret = 0;
3090         int i;
3091         u64 rel_ptr;
3092         int size;
3093         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3094         struct inode_fs_paths *ipath = NULL;
3095         struct btrfs_path *path;
3096
3097         if (!capable(CAP_SYS_ADMIN))
3098                 return -EPERM;
3099
3100         path = btrfs_alloc_path();
3101         if (!path) {
3102                 ret = -ENOMEM;
3103                 goto out;
3104         }
3105
3106         ipa = memdup_user(arg, sizeof(*ipa));
3107         if (IS_ERR(ipa)) {
3108                 ret = PTR_ERR(ipa);
3109                 ipa = NULL;
3110                 goto out;
3111         }
3112
3113         size = min_t(u32, ipa->size, 4096);
3114         ipath = init_ipath(size, root, path);
3115         if (IS_ERR(ipath)) {
3116                 ret = PTR_ERR(ipath);
3117                 ipath = NULL;
3118                 goto out;
3119         }
3120
3121         ret = paths_from_inode(ipa->inum, ipath);
3122         if (ret < 0)
3123                 goto out;
3124
3125         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3126                 rel_ptr = ipath->fspath->val[i] -
3127                           (u64)(unsigned long)ipath->fspath->val;
3128                 ipath->fspath->val[i] = rel_ptr;
3129         }
3130
3131         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
3132                            (void *)(unsigned long)ipath->fspath, size);
3133         if (ret) {
3134                 ret = -EFAULT;
3135                 goto out;
3136         }
3137
3138 out:
3139         btrfs_free_path(path);
3140         free_ipath(ipath);
3141         kfree(ipa);
3142
3143         return ret;
3144 }
3145
3146 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3147 {
3148         struct btrfs_data_container *inodes = ctx;
3149         const size_t c = 3 * sizeof(u64);
3150
3151         if (inodes->bytes_left >= c) {
3152                 inodes->bytes_left -= c;
3153                 inodes->val[inodes->elem_cnt] = inum;
3154                 inodes->val[inodes->elem_cnt + 1] = offset;
3155                 inodes->val[inodes->elem_cnt + 2] = root;
3156                 inodes->elem_cnt += 3;
3157         } else {
3158                 inodes->bytes_missing += c - inodes->bytes_left;
3159                 inodes->bytes_left = 0;
3160                 inodes->elem_missed += 3;
3161         }
3162
3163         return 0;
3164 }
3165
3166 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3167                                         void __user *arg)
3168 {
3169         int ret = 0;
3170         int size;
3171         u64 extent_item_pos;
3172         struct btrfs_ioctl_logical_ino_args *loi;
3173         struct btrfs_data_container *inodes = NULL;
3174         struct btrfs_path *path = NULL;
3175         struct btrfs_key key;
3176
3177         if (!capable(CAP_SYS_ADMIN))
3178                 return -EPERM;
3179
3180         loi = memdup_user(arg, sizeof(*loi));
3181         if (IS_ERR(loi)) {
3182                 ret = PTR_ERR(loi);
3183                 loi = NULL;
3184                 goto out;
3185         }
3186
3187         path = btrfs_alloc_path();
3188         if (!path) {
3189                 ret = -ENOMEM;
3190                 goto out;
3191         }
3192
3193         size = min_t(u32, loi->size, 4096);
3194         inodes = init_data_container(size);
3195         if (IS_ERR(inodes)) {
3196                 ret = PTR_ERR(inodes);
3197                 inodes = NULL;
3198                 goto out;
3199         }
3200
3201         ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
3202         btrfs_release_path(path);
3203
3204         if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
3205                 ret = -ENOENT;
3206         if (ret < 0)
3207                 goto out;
3208
3209         extent_item_pos = loi->logical - key.objectid;
3210         ret = iterate_extent_inodes(root->fs_info, key.objectid,
3211                                         extent_item_pos, 0, build_ino_list,
3212                                         inodes);
3213
3214         if (ret < 0)
3215                 goto out;
3216
3217         ret = copy_to_user((void *)(unsigned long)loi->inodes,
3218                            (void *)(unsigned long)inodes, size);
3219         if (ret)
3220                 ret = -EFAULT;
3221
3222 out:
3223         btrfs_free_path(path);
3224         kfree(inodes);
3225         kfree(loi);
3226
3227         return ret;
3228 }
3229
3230 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3231                                struct btrfs_ioctl_balance_args *bargs)
3232 {
3233         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3234
3235         bargs->flags = bctl->flags;
3236
3237         if (atomic_read(&fs_info->balance_running))
3238                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3239         if (atomic_read(&fs_info->balance_pause_req))
3240                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3241         if (atomic_read(&fs_info->balance_cancel_req))
3242                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3243
3244         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3245         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3246         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3247
3248         if (lock) {
3249                 spin_lock(&fs_info->balance_lock);
3250                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3251                 spin_unlock(&fs_info->balance_lock);
3252         } else {
3253                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3254         }
3255 }
3256
3257 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3258 {
3259         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3260         struct btrfs_fs_info *fs_info = root->fs_info;
3261         struct btrfs_ioctl_balance_args *bargs;
3262         struct btrfs_balance_control *bctl;
3263         int ret;
3264
3265         if (!capable(CAP_SYS_ADMIN))
3266                 return -EPERM;
3267
3268         if (fs_info->sb->s_flags & MS_RDONLY)
3269                 return -EROFS;
3270
3271         ret = mnt_want_write_file(file);
3272         if (ret)
3273                 return ret;
3274
3275         mutex_lock(&fs_info->volume_mutex);
3276         mutex_lock(&fs_info->balance_mutex);
3277
3278         if (arg) {
3279                 bargs = memdup_user(arg, sizeof(*bargs));
3280                 if (IS_ERR(bargs)) {
3281                         ret = PTR_ERR(bargs);
3282                         goto out;
3283                 }
3284
3285                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
3286                         if (!fs_info->balance_ctl) {
3287                                 ret = -ENOTCONN;
3288                                 goto out_bargs;
3289                         }
3290
3291                         bctl = fs_info->balance_ctl;
3292                         spin_lock(&fs_info->balance_lock);
3293                         bctl->flags |= BTRFS_BALANCE_RESUME;
3294                         spin_unlock(&fs_info->balance_lock);
3295
3296                         goto do_balance;
3297                 }
3298         } else {
3299                 bargs = NULL;
3300         }
3301
3302         if (fs_info->balance_ctl) {
3303                 ret = -EINPROGRESS;
3304                 goto out_bargs;
3305         }
3306
3307         bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3308         if (!bctl) {
3309                 ret = -ENOMEM;
3310                 goto out_bargs;
3311         }
3312
3313         bctl->fs_info = fs_info;
3314         if (arg) {
3315                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3316                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3317                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3318
3319                 bctl->flags = bargs->flags;
3320         } else {
3321                 /* balance everything - no filters */
3322                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3323         }
3324
3325 do_balance:
3326         ret = btrfs_balance(bctl, bargs);
3327         /*
3328          * bctl is freed in __cancel_balance or in free_fs_info if
3329          * restriper was paused all the way until unmount
3330          */
3331         if (arg) {
3332                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3333                         ret = -EFAULT;
3334         }
3335
3336 out_bargs:
3337         kfree(bargs);
3338 out:
3339         mutex_unlock(&fs_info->balance_mutex);
3340         mutex_unlock(&fs_info->volume_mutex);
3341         mnt_drop_write_file(file);
3342         return ret;
3343 }
3344
3345 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
3346 {
3347         if (!capable(CAP_SYS_ADMIN))
3348                 return -EPERM;
3349
3350         switch (cmd) {
3351         case BTRFS_BALANCE_CTL_PAUSE:
3352                 return btrfs_pause_balance(root->fs_info);
3353         case BTRFS_BALANCE_CTL_CANCEL:
3354                 return btrfs_cancel_balance(root->fs_info);
3355         }
3356
3357         return -EINVAL;
3358 }
3359
3360 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
3361                                          void __user *arg)
3362 {
3363         struct btrfs_fs_info *fs_info = root->fs_info;
3364         struct btrfs_ioctl_balance_args *bargs;
3365         int ret = 0;
3366
3367         if (!capable(CAP_SYS_ADMIN))
3368                 return -EPERM;
3369
3370         mutex_lock(&fs_info->balance_mutex);
3371         if (!fs_info->balance_ctl) {
3372                 ret = -ENOTCONN;
3373                 goto out;
3374         }
3375
3376         bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
3377         if (!bargs) {
3378                 ret = -ENOMEM;
3379                 goto out;
3380         }
3381
3382         update_ioctl_balance_args(fs_info, 1, bargs);
3383
3384         if (copy_to_user(arg, bargs, sizeof(*bargs)))
3385                 ret = -EFAULT;
3386
3387         kfree(bargs);
3388 out:
3389         mutex_unlock(&fs_info->balance_mutex);
3390         return ret;
3391 }
3392
3393 long btrfs_ioctl(struct file *file, unsigned int
3394                 cmd, unsigned long arg)
3395 {
3396         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3397         void __user *argp = (void __user *)arg;
3398
3399         switch (cmd) {
3400         case FS_IOC_GETFLAGS:
3401                 return btrfs_ioctl_getflags(file, argp);
3402         case FS_IOC_SETFLAGS:
3403                 return btrfs_ioctl_setflags(file, argp);
3404         case FS_IOC_GETVERSION:
3405                 return btrfs_ioctl_getversion(file, argp);
3406         case FITRIM:
3407                 return btrfs_ioctl_fitrim(file, argp);
3408         case BTRFS_IOC_SNAP_CREATE:
3409                 return btrfs_ioctl_snap_create(file, argp, 0);
3410         case BTRFS_IOC_SNAP_CREATE_V2:
3411                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
3412         case BTRFS_IOC_SUBVOL_CREATE:
3413                 return btrfs_ioctl_snap_create(file, argp, 1);
3414         case BTRFS_IOC_SNAP_DESTROY:
3415                 return btrfs_ioctl_snap_destroy(file, argp);
3416         case BTRFS_IOC_SUBVOL_GETFLAGS:
3417                 return btrfs_ioctl_subvol_getflags(file, argp);
3418         case BTRFS_IOC_SUBVOL_SETFLAGS:
3419                 return btrfs_ioctl_subvol_setflags(file, argp);
3420         case BTRFS_IOC_DEFAULT_SUBVOL:
3421                 return btrfs_ioctl_default_subvol(file, argp);
3422         case BTRFS_IOC_DEFRAG:
3423                 return btrfs_ioctl_defrag(file, NULL);
3424         case BTRFS_IOC_DEFRAG_RANGE:
3425                 return btrfs_ioctl_defrag(file, argp);
3426         case BTRFS_IOC_RESIZE:
3427                 return btrfs_ioctl_resize(root, argp);
3428         case BTRFS_IOC_ADD_DEV:
3429                 return btrfs_ioctl_add_dev(root, argp);
3430         case BTRFS_IOC_RM_DEV:
3431                 return btrfs_ioctl_rm_dev(root, argp);
3432         case BTRFS_IOC_FS_INFO:
3433                 return btrfs_ioctl_fs_info(root, argp);
3434         case BTRFS_IOC_DEV_INFO:
3435                 return btrfs_ioctl_dev_info(root, argp);
3436         case BTRFS_IOC_BALANCE:
3437                 return btrfs_ioctl_balance(file, NULL);
3438         case BTRFS_IOC_CLONE:
3439                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3440         case BTRFS_IOC_CLONE_RANGE:
3441                 return btrfs_ioctl_clone_range(file, argp);
3442         case BTRFS_IOC_TRANS_START:
3443                 return btrfs_ioctl_trans_start(file);
3444         case BTRFS_IOC_TRANS_END:
3445                 return btrfs_ioctl_trans_end(file);
3446         case BTRFS_IOC_TREE_SEARCH:
3447                 return btrfs_ioctl_tree_search(file, argp);
3448         case BTRFS_IOC_INO_LOOKUP:
3449                 return btrfs_ioctl_ino_lookup(file, argp);
3450         case BTRFS_IOC_INO_PATHS:
3451                 return btrfs_ioctl_ino_to_path(root, argp);
3452         case BTRFS_IOC_LOGICAL_INO:
3453                 return btrfs_ioctl_logical_to_ino(root, argp);
3454         case BTRFS_IOC_SPACE_INFO:
3455                 return btrfs_ioctl_space_info(root, argp);
3456         case BTRFS_IOC_SYNC:
3457                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
3458                 return 0;
3459         case BTRFS_IOC_START_SYNC:
3460                 return btrfs_ioctl_start_sync(file, argp);
3461         case BTRFS_IOC_WAIT_SYNC:
3462                 return btrfs_ioctl_wait_sync(file, argp);
3463         case BTRFS_IOC_SCRUB:
3464                 return btrfs_ioctl_scrub(root, argp);
3465         case BTRFS_IOC_SCRUB_CANCEL:
3466                 return btrfs_ioctl_scrub_cancel(root, argp);
3467         case BTRFS_IOC_SCRUB_PROGRESS:
3468                 return btrfs_ioctl_scrub_progress(root, argp);
3469         case BTRFS_IOC_BALANCE_V2:
3470                 return btrfs_ioctl_balance(file, argp);
3471         case BTRFS_IOC_BALANCE_CTL:
3472                 return btrfs_ioctl_balance_ctl(root, arg);
3473         case BTRFS_IOC_BALANCE_PROGRESS:
3474                 return btrfs_ioctl_balance_progress(root, argp);
3475         case BTRFS_IOC_GET_DEV_STATS:
3476                 return btrfs_ioctl_get_dev_stats(root, argp, 0);
3477         case BTRFS_IOC_GET_AND_RESET_DEV_STATS:
3478                 return btrfs_ioctl_get_dev_stats(root, argp, 1);
3479         }
3480
3481         return -ENOTTY;
3482 }