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