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