fs/btrfs/ioctl.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/bio.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/file.h>
  23 #include <linux/fs.h>
  24 #include <linux/fsnotify.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/highmem.h>
  27 #include <linux/time.h>
  28 #include <linux/init.h>
  29 #include <linux/string.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/mount.h>
  32 #include <linux/mpage.h>
  33 #include <linux/namei.h>
  34 #include <linux/swap.h>
  35 #include <linux/writeback.h>
  36 #include <linux/statfs.h>
  37 #include <linux/compat.h>
  38 #include <linux/bit_spinlock.h>
  39 #include <linux/security.h>
  40 #include <linux/xattr.h>
  41 #include <linux/vmalloc.h>
  42 #include <linux/slab.h>
  43 #include <linux/blkdev.h>
  44 #include <linux/uuid.h>
  45 #include "compat.h"
  46 #include "ctree.h"
  47 #include "disk-io.h"
  48 #include "transaction.h"
  49 #include "btrfs_inode.h"
  50 #include "ioctl.h"
  51 #include "print-tree.h"
  52 #include "volumes.h"
  53 #include "locking.h"
  54 #include "inode-map.h"
  55 #include "backref.h"
  56 #include "rcu-string.h"
  57 #include "send.h"
  58
  59 /* Mask out flags that are inappropriate for the given type of inode. */
  60 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  61 {
  62         if (S_ISDIR(mode))
  63                 return flags;
  64         else if (S_ISREG(mode))
  65                 return flags & ~FS_DIRSYNC_FL;
  66         else
  67                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  68 }
  69
  70 /*
  71  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  72  */
  73 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  74 {
  75         unsigned int iflags = 0;
  76
  77         if (flags & BTRFS_INODE_SYNC)
  78                 iflags |= FS_SYNC_FL;
  79         if (flags & BTRFS_INODE_IMMUTABLE)
  80                 iflags |= FS_IMMUTABLE_FL;
  81         if (flags & BTRFS_INODE_APPEND)
  82                 iflags |= FS_APPEND_FL;
  83         if (flags & BTRFS_INODE_NODUMP)
  84                 iflags |= FS_NODUMP_FL;
  85         if (flags & BTRFS_INODE_NOATIME)
  86                 iflags |= FS_NOATIME_FL;
  87         if (flags & BTRFS_INODE_DIRSYNC)
  88                 iflags |= FS_DIRSYNC_FL;
  89         if (flags & BTRFS_INODE_NODATACOW)
  90                 iflags |= FS_NOCOW_FL;
  91
  92         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
  93                 iflags |= FS_COMPR_FL;
  94         else if (flags & BTRFS_INODE_NOCOMPRESS)
  95                 iflags |= FS_NOCOMP_FL;
  96
  97         return iflags;
  98 }
  99
 100 /*
 101  * Update inode->i_flags based on the btrfs internal flags.
 102  */
 103 void btrfs_update_iflags(struct inode *inode)
 104 {
 105         struct btrfs_inode *ip = BTRFS_I(inode);
 106
 107         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 108
 109         if (ip->flags & BTRFS_INODE_SYNC)
 110                 inode->i_flags |= S_SYNC;
 111         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 112                 inode->i_flags |= S_IMMUTABLE;
 113         if (ip->flags & BTRFS_INODE_APPEND)
 114                 inode->i_flags |= S_APPEND;
 115         if (ip->flags & BTRFS_INODE_NOATIME)
 116                 inode->i_flags |= S_NOATIME;
 117         if (ip->flags & BTRFS_INODE_DIRSYNC)
 118                 inode->i_flags |= S_DIRSYNC;
 119 }
 120
 121 /*
 122  * Inherit flags from the parent inode.
 123  *
 124  * Currently only the compression flags and the cow flags are inherited.
 125  */
 126 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 127 {
 128         unsigned int flags;
 129
 130         if (!dir)
 131                 return;
 132
 133         flags = BTRFS_I(dir)->flags;
 134
 135         if (flags & BTRFS_INODE_NOCOMPRESS) {
 136                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 137                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 138         } else if (flags & BTRFS_INODE_COMPRESS) {
 139                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 140                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 141         }
 142
 143         if (flags & BTRFS_INODE_NODATACOW)
 144                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 145
 146         btrfs_update_iflags(inode);
 147 }
 148
 149 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 150 {
 151         struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
 152         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 153
 154         if (copy_to_user(arg, &flags, sizeof(flags)))
 155                 return -EFAULT;
 156         return 0;
 157 }
 158
 159 static int check_flags(unsigned int flags)
 160 {
 161         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 162                       FS_NOATIME_FL | FS_NODUMP_FL | \
 163                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 164                       FS_NOCOMP_FL | FS_COMPR_FL |
 165                       FS_NOCOW_FL))
 166                 return -EOPNOTSUPP;
 167
 168         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 169                 return -EINVAL;
 170
 171         return 0;
 172 }
 173
 174 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 175 {
 176         struct inode *inode = file->f_path.dentry->d_inode;
 177         struct btrfs_inode *ip = BTRFS_I(inode);
 178         struct btrfs_root *root = ip->root;
 179         struct btrfs_trans_handle *trans;
 180         unsigned int flags, oldflags;
 181         int ret;
 182         u64 ip_oldflags;
 183         unsigned int i_oldflags;
 184
 185         if (btrfs_root_readonly(root))
 186                 return -EROFS;
 187
 188         if (copy_from_user(&flags, arg, sizeof(flags)))
 189                 return -EFAULT;
 190
 191         ret = check_flags(flags);
 192         if (ret)
 193                 return ret;
 194
 195         if (!inode_owner_or_capable(inode))
 196                 return -EACCES;
 197
 198         ret = mnt_want_write_file(file);
 199         if (ret)
 200                 return ret;
 201
 202         mutex_lock(&inode->i_mutex);
 203
 204         ip_oldflags = ip->flags;
 205         i_oldflags = inode->i_flags;
 206
 207         flags = btrfs_mask_flags(inode->i_mode, flags);
 208         oldflags = btrfs_flags_to_ioctl(ip->flags);
 209         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 210                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 211                         ret = -EPERM;
 212                         goto out_unlock;
 213                 }
 214         }
 215
 216         if (flags & FS_SYNC_FL)
 217                 ip->flags |= BTRFS_INODE_SYNC;
 218         else
 219                 ip->flags &= ~BTRFS_INODE_SYNC;
 220         if (flags & FS_IMMUTABLE_FL)
 221                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 222         else
 223                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 224         if (flags & FS_APPEND_FL)
 225                 ip->flags |= BTRFS_INODE_APPEND;
 226         else
 227                 ip->flags &= ~BTRFS_INODE_APPEND;
 228         if (flags & FS_NODUMP_FL)
 229                 ip->flags |= BTRFS_INODE_NODUMP;
 230         else
 231                 ip->flags &= ~BTRFS_INODE_NODUMP;
 232         if (flags & FS_NOATIME_FL)
 233                 ip->flags |= BTRFS_INODE_NOATIME;
 234         else
 235                 ip->flags &= ~BTRFS_INODE_NOATIME;
 236         if (flags & FS_DIRSYNC_FL)
 237                 ip->flags |= BTRFS_INODE_DIRSYNC;
 238         else
 239                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 240         if (flags & FS_NOCOW_FL)
 241                 ip->flags |= BTRFS_INODE_NODATACOW;
 242         else
 243                 ip->flags &= ~BTRFS_INODE_NODATACOW;
 244
 245         /*
 246          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 247          * flag may be changed automatically if compression code won't make
 248          * things smaller.
 249          */
 250         if (flags & FS_NOCOMP_FL) {
 251                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 252                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 253         } else if (flags & FS_COMPR_FL) {
 254                 ip->flags |= BTRFS_INODE_COMPRESS;
 255                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 256         } else {
 257                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 258         }
 259
 260         trans = btrfs_start_transaction(root, 1);
 261         if (IS_ERR(trans)) {
 262                 ret = PTR_ERR(trans);
 263                 goto out_drop;
 264         }
 265
 266         btrfs_update_iflags(inode);
 267         inode_inc_iversion(inode);
 268         inode->i_ctime = CURRENT_TIME;
 269         ret = btrfs_update_inode(trans, root, inode);
 270
 271         btrfs_end_transaction(trans, root);
 272  out_drop:
 273         if (ret) {
 274                 ip->flags = ip_oldflags;
 275                 inode->i_flags = i_oldflags;
 276         }
 277
 278  out_unlock:
 279         mutex_unlock(&inode->i_mutex);
 280         mnt_drop_write_file(file);
 281         return ret;
 282 }
 283
 284 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 285 {
 286         struct inode *inode = file->f_path.dentry->d_inode;
 287
 288         return put_user(inode->i_generation, arg);
 289 }
 290
 291 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 292 {
 293         struct btrfs_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
 294         struct btrfs_device *device;
 295         struct request_queue *q;
 296         struct fstrim_range range;
 297         u64 minlen = ULLONG_MAX;
 298         u64 num_devices = 0;
 299         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 300         int ret;
 301
 302         if (!capable(CAP_SYS_ADMIN))
 303                 return -EPERM;
 304
 305         rcu_read_lock();
 306         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 307                                 dev_list) {
 308                 if (!device->bdev)
 309                         continue;
 310                 q = bdev_get_queue(device->bdev);
 311                 if (blk_queue_discard(q)) {
 312                         num_devices++;
 313                         minlen = min((u64)q->limits.discard_granularity,
 314                                      minlen);
 315                 }
 316         }
 317         rcu_read_unlock();
 318
 319         if (!num_devices)
 320                 return -EOPNOTSUPP;
 321         if (copy_from_user(&range, arg, sizeof(range)))
 322                 return -EFAULT;
 323         if (range.start > total_bytes)
 324                 return -EINVAL;
 325
 326         range.len = min(range.len, total_bytes - range.start);
 327         range.minlen = max(range.minlen, minlen);
 328         ret = btrfs_trim_fs(fs_info->tree_root, &range);
 329         if (ret < 0)
 330                 return ret;
 331
 332         if (copy_to_user(arg, &range, sizeof(range)))
 333                 return -EFAULT;
 334
 335         return 0;
 336 }
 337
 338 static noinline int create_subvol(struct btrfs_root *root,
 339                                   struct dentry *dentry,
 340                                   char *name, int namelen,
 341                                   u64 *async_transid,
 342                                   struct btrfs_qgroup_inherit **inherit)
 343 {
 344         struct btrfs_trans_handle *trans;
 345         struct btrfs_key key;
 346         struct btrfs_root_item root_item;
 347         struct btrfs_inode_item *inode_item;
 348         struct extent_buffer *leaf;
 349         struct btrfs_root *new_root;
 350         struct dentry *parent = dentry->d_parent;
 351         struct inode *dir;
 352         struct timespec cur_time = CURRENT_TIME;
 353         int ret;
 354         int err;
 355         u64 objectid;
 356         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 357         u64 index = 0;
 358         uuid_le new_uuid;
 359
 360         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 361         if (ret)
 362                 return ret;
 363
 364         dir = parent->d_inode;
 365
 366         /*
 367          * 1 - inode item
 368          * 2 - refs
 369          * 1 - root item
 370          * 2 - dir items
 371          */
 372         trans = btrfs_start_transaction(root, 6);
 373         if (IS_ERR(trans))
 374                 return PTR_ERR(trans);
 375
 376         ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid,
 377                                    inherit ? *inherit : NULL);
 378         if (ret)
 379                 goto fail;
 380
 381         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 382                                       0, objectid, NULL, 0, 0, 0);
 383         if (IS_ERR(leaf)) {
 384                 ret = PTR_ERR(leaf);
 385                 goto fail;
 386         }
 387
 388         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 389         btrfs_set_header_bytenr(leaf, leaf->start);
 390         btrfs_set_header_generation(leaf, trans->transid);
 391         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 392         btrfs_set_header_owner(leaf, objectid);
 393
 394         write_extent_buffer(leaf, root->fs_info->fsid,
 395                             (unsigned long)btrfs_header_fsid(leaf),
 396                             BTRFS_FSID_SIZE);
 397         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 398                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 399                             BTRFS_UUID_SIZE);
 400         btrfs_mark_buffer_dirty(leaf);
 401
 402         memset(&root_item, 0, sizeof(root_item));
 403
 404         inode_item = &root_item.inode;
 405         inode_item->generation = cpu_to_le64(1);
 406         inode_item->size = cpu_to_le64(3);
 407         inode_item->nlink = cpu_to_le32(1);
 408         inode_item->nbytes = cpu_to_le64(root->leafsize);
 409         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 410
 411         root_item.flags = 0;
 412         root_item.byte_limit = 0;
 413         inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
 414
 415         btrfs_set_root_bytenr(&root_item, leaf->start);
 416         btrfs_set_root_generation(&root_item, trans->transid);
 417         btrfs_set_root_level(&root_item, 0);
 418         btrfs_set_root_refs(&root_item, 1);
 419         btrfs_set_root_used(&root_item, leaf->len);
 420         btrfs_set_root_last_snapshot(&root_item, 0);
 421
 422         btrfs_set_root_generation_v2(&root_item,
 423                         btrfs_root_generation(&root_item));
 424         uuid_le_gen(&new_uuid);
 425         memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
 426         root_item.otime.sec = cpu_to_le64(cur_time.tv_sec);
 427         root_item.otime.nsec = cpu_to_le32(cur_time.tv_nsec);
 428         root_item.ctime = root_item.otime;
 429         btrfs_set_root_ctransid(&root_item, trans->transid);
 430         btrfs_set_root_otransid(&root_item, trans->transid);
 431
 432         btrfs_tree_unlock(leaf);
 433         free_extent_buffer(leaf);
 434         leaf = NULL;
 435
 436         btrfs_set_root_dirid(&root_item, new_dirid);
 437
 438         key.objectid = objectid;
 439         key.offset = 0;
 440         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 441         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 442                                 &root_item);
 443         if (ret)
 444                 goto fail;
 445
 446         key.offset = (u64)-1;
 447         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 448         if (IS_ERR(new_root)) {
 449                 btrfs_abort_transaction(trans, root, PTR_ERR(new_root));
 450                 ret = PTR_ERR(new_root);
 451                 goto fail;
 452         }
 453
 454         btrfs_record_root_in_trans(trans, new_root);
 455
 456         ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
 457         if (ret) {
 458                 /* We potentially lose an unused inode item here */
 459                 btrfs_abort_transaction(trans, root, ret);
 460                 goto fail;
 461         }
 462
 463         /*
 464          * insert the directory item
 465          */
 466         ret = btrfs_set_inode_index(dir, &index);
 467         if (ret) {
 468                 btrfs_abort_transaction(trans, root, ret);
 469                 goto fail;
 470         }
 471
 472         ret = btrfs_insert_dir_item(trans, root,
 473                                     name, namelen, dir, &key,
 474                                     BTRFS_FT_DIR, index);
 475         if (ret) {
 476                 btrfs_abort_transaction(trans, root, ret);
 477                 goto fail;
 478         }
 479
 480         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 481         ret = btrfs_update_inode(trans, root, dir);
 482         BUG_ON(ret);
 483
 484         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 485                                  objectid, root->root_key.objectid,
 486                                  btrfs_ino(dir), index, name, namelen);
 487
 488         BUG_ON(ret);
 489
 490         d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 491 fail:
 492         if (async_transid) {
 493                 *async_transid = trans->transid;
 494                 err = btrfs_commit_transaction_async(trans, root, 1);
 495         } else {
 496                 err = btrfs_commit_transaction(trans, root);
 497         }
 498         if (err && !ret)
 499                 ret = err;
 500         return ret;
 501 }
 502
 503 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 504                            char *name, int namelen, u64 *async_transid,
 505                            bool readonly, struct btrfs_qgroup_inherit **inherit)
 506 {
 507         struct inode *inode;
 508         struct btrfs_pending_snapshot *pending_snapshot;
 509         struct btrfs_trans_handle *trans;
 510         int ret;
 511
 512         if (!root->ref_cows)
 513                 return -EINVAL;
 514
 515         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 516         if (!pending_snapshot)
 517                 return -ENOMEM;
 518
 519         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 520                              BTRFS_BLOCK_RSV_TEMP);
 521         pending_snapshot->dentry = dentry;
 522         pending_snapshot->root = root;
 523         pending_snapshot->readonly = readonly;
 524         if (inherit) {
 525                 pending_snapshot->inherit = *inherit;
 526                 *inherit = NULL;        /* take responsibility to free it */
 527         }
 528
 529         trans = btrfs_start_transaction(root->fs_info->extent_root, 6);
 530         if (IS_ERR(trans)) {
 531                 ret = PTR_ERR(trans);
 532                 goto fail;
 533         }
 534
 535         ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
 536         BUG_ON(ret);
 537
 538         spin_lock(&root->fs_info->trans_lock);
 539         list_add(&pending_snapshot->list,
 540                  &trans->transaction->pending_snapshots);
 541         spin_unlock(&root->fs_info->trans_lock);
 542         if (async_transid) {
 543                 *async_transid = trans->transid;
 544                 ret = btrfs_commit_transaction_async(trans,
 545                                      root->fs_info->extent_root, 1);
 546         } else {
 547                 ret = btrfs_commit_transaction(trans,
 548                                                root->fs_info->extent_root);
 549         }
 550         BUG_ON(ret);
 551
 552         ret = pending_snapshot->error;
 553         if (ret)
 554                 goto fail;
 555
 556         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 557         if (ret)
 558                 goto fail;
 559
 560         inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 561         if (IS_ERR(inode)) {
 562                 ret = PTR_ERR(inode);
 563                 goto fail;
 564         }
 565         BUG_ON(!inode);
 566         d_instantiate(dentry, inode);
 567         ret = 0;
 568 fail:
 569         kfree(pending_snapshot);
 570         return ret;
 571 }
 572
 573 /*  copy of check_sticky in fs/namei.c()
 574 * It's inline, so penalty for filesystems that don't use sticky bit is
 575 * minimal.
 576 */
 577 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
 578 {
 579         uid_t fsuid = current_fsuid();
 580
 581         if (!(dir->i_mode & S_ISVTX))
 582                 return 0;
 583         if (inode->i_uid == fsuid)
 584                 return 0;
 585         if (dir->i_uid == fsuid)
 586                 return 0;
 587         return !capable(CAP_FOWNER);
 588 }
 589
 590 /*  copy of may_delete in fs/namei.c()
 591  *      Check whether we can remove a link victim from directory dir, check
 592  *  whether the type of victim is right.
 593  *  1. We can't do it if dir is read-only (done in permission())
 594  *  2. We should have write and exec permissions on dir
 595  *  3. We can't remove anything from append-only dir
 596  *  4. We can't do anything with immutable dir (done in permission())
 597  *  5. If the sticky bit on dir is set we should either
 598  *      a. be owner of dir, or
 599  *      b. be owner of victim, or
 600  *      c. have CAP_FOWNER capability
 601  *  6. If the victim is append-only or immutable we can't do antyhing with
 602  *     links pointing to it.
 603  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 604  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 605  *  9. We can't remove a root or mountpoint.
 606  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 607  *     nfs_async_unlink().
 608  */
 609
 610 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
 611 {
 612         int error;
 613
 614         if (!victim->d_inode)
 615                 return -ENOENT;
 616
 617         BUG_ON(victim->d_parent->d_inode != dir);
 618         audit_inode_child(victim, dir);
 619
 620         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 621         if (error)
 622                 return error;
 623         if (IS_APPEND(dir))
 624                 return -EPERM;
 625         if (btrfs_check_sticky(dir, victim->d_inode)||
 626                 IS_APPEND(victim->d_inode)||
 627             IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
 628                 return -EPERM;
 629         if (isdir) {
 630                 if (!S_ISDIR(victim->d_inode->i_mode))
 631                         return -ENOTDIR;
 632                 if (IS_ROOT(victim))
 633                         return -EBUSY;
 634         } else if (S_ISDIR(victim->d_inode->i_mode))
 635                 return -EISDIR;
 636         if (IS_DEADDIR(dir))
 637                 return -ENOENT;
 638         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 639                 return -EBUSY;
 640         return 0;
 641 }
 642
 643 /* copy of may_create in fs/namei.c() */
 644 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 645 {
 646         if (child->d_inode)
 647                 return -EEXIST;
 648         if (IS_DEADDIR(dir))
 649                 return -ENOENT;
 650         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 651 }
 652
 653 /*
 654  * Create a new subvolume below @parent.  This is largely modeled after
 655  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 656  * inside this filesystem so it's quite a bit simpler.
 657  */
 658 static noinline int btrfs_mksubvol(struct path *parent,
 659                                    char *name, int namelen,
 660                                    struct btrfs_root *snap_src,
 661                                    u64 *async_transid, bool readonly,
 662                                    struct btrfs_qgroup_inherit **inherit)
 663 {
 664         struct inode *dir  = parent->dentry->d_inode;
 665         struct dentry *dentry;
 666         int error;
 667
 668         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 669
 670         dentry = lookup_one_len(name, parent->dentry, namelen);
 671         error = PTR_ERR(dentry);
 672         if (IS_ERR(dentry))
 673                 goto out_unlock;
 674
 675         error = -EEXIST;
 676         if (dentry->d_inode)
 677                 goto out_dput;
 678
 679         error = btrfs_may_create(dir, dentry);
 680         if (error)
 681                 goto out_dput;
 682
 683         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 684
 685         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 686                 goto out_up_read;
 687
 688         if (snap_src) {
 689                 error = create_snapshot(snap_src, dentry, name, namelen,
 690                                         async_transid, readonly, inherit);
 691         } else {
 692                 error = create_subvol(BTRFS_I(dir)->root, dentry,
 693                                       name, namelen, async_transid, inherit);
 694         }
 695         if (!error)
 696                 fsnotify_mkdir(dir, dentry);
 697 out_up_read:
 698         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 699 out_dput:
 700         dput(dentry);
 701 out_unlock:
 702         mutex_unlock(&dir->i_mutex);
 703         return error;
 704 }
 705
 706 /*
 707  * When we're defragging a range, we don't want to kick it off again
 708  * if it is really just waiting for delalloc to send it down.
 709  * If we find a nice big extent or delalloc range for the bytes in the
 710  * file you want to defrag, we return 0 to let you know to skip this
 711  * part of the file
 712  */
 713 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
 714 {
 715         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 716         struct extent_map *em = NULL;
 717         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 718         u64 end;
 719
 720         read_lock(&em_tree->lock);
 721         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 722         read_unlock(&em_tree->lock);
 723
 724         if (em) {
 725                 end = extent_map_end(em);
 726                 free_extent_map(em);
 727                 if (end - offset > thresh)
 728                         return 0;
 729         }
 730         /* if we already have a nice delalloc here, just stop */
 731         thresh /= 2;
 732         end = count_range_bits(io_tree, &offset, offset + thresh,
 733                                thresh, EXTENT_DELALLOC, 1);
 734         if (end >= thresh)
 735                 return 0;
 736         return 1;
 737 }
 738
 739 /*
 740  * helper function to walk through a file and find extents
 741  * newer than a specific transid, and smaller than thresh.
 742  *
 743  * This is used by the defragging code to find new and small
 744  * extents
 745  */
 746 static int find_new_extents(struct btrfs_root *root,
 747                             struct inode *inode, u64 newer_than,
 748                             u64 *off, int thresh)
 749 {
 750         struct btrfs_path *path;
 751         struct btrfs_key min_key;
 752         struct btrfs_key max_key;
 753         struct extent_buffer *leaf;
 754         struct btrfs_file_extent_item *extent;
 755         int type;
 756         int ret;
 757         u64 ino = btrfs_ino(inode);
 758
 759         path = btrfs_alloc_path();
 760         if (!path)
 761                 return -ENOMEM;
 762
 763         min_key.objectid = ino;
 764         min_key.type = BTRFS_EXTENT_DATA_KEY;
 765         min_key.offset = *off;
 766
 767         max_key.objectid = ino;
 768         max_key.type = (u8)-1;
 769         max_key.offset = (u64)-1;
 770
 771         path->keep_locks = 1;
 772
 773         while(1) {
 774                 ret = btrfs_search_forward(root, &min_key, &max_key,
 775                                            path, 0, newer_than);
 776                 if (ret != 0)
 777                         goto none;
 778                 if (min_key.objectid != ino)
 779                         goto none;
 780                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 781                         goto none;
 782
 783                 leaf = path->nodes[0];
 784                 extent = btrfs_item_ptr(leaf, path->slots[0],
 785                                         struct btrfs_file_extent_item);
 786
 787                 type = btrfs_file_extent_type(leaf, extent);
 788                 if (type == BTRFS_FILE_EXTENT_REG &&
 789                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 790                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 791                         *off = min_key.offset;
 792                         btrfs_free_path(path);
 793                         return 0;
 794                 }
 795
 796                 if (min_key.offset == (u64)-1)
 797                         goto none;
 798
 799                 min_key.offset++;
 800                 btrfs_release_path(path);
 801         }
 802 none:
 803         btrfs_free_path(path);
 804         return -ENOENT;
 805 }
 806
 807 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 808 {
 809         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 810         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 811         struct extent_map *em;
 812         u64 len = PAGE_CACHE_SIZE;
 813
 814         /*
 815          * hopefully we have this extent in the tree already, try without
 816          * the full extent lock
 817          */
 818         read_lock(&em_tree->lock);
 819         em = lookup_extent_mapping(em_tree, start, len);
 820         read_unlock(&em_tree->lock);
 821
 822         if (!em) {
 823                 /* get the big lock and read metadata off disk */
 824                 lock_extent(io_tree, start, start + len - 1);
 825                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 826                 unlock_extent(io_tree, start, start + len - 1);
 827
 828                 if (IS_ERR(em))
 829                         return NULL;
 830         }
 831
 832         return em;
 833 }
 834
 835 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 836 {
 837         struct extent_map *next;
 838         bool ret = true;
 839
 840         /* this is the last extent */
 841         if (em->start + em->len >= i_size_read(inode))
 842                 return false;
 843
 844         next = defrag_lookup_extent(inode, em->start + em->len);
 845         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
 846                 ret = false;
 847
 848         free_extent_map(next);
 849         return ret;
 850 }
 851
 852 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
 853                                u64 *last_len, u64 *skip, u64 *defrag_end,
 854                                int compress)
 855 {
 856         struct extent_map *em;
 857         int ret = 1;
 858         bool next_mergeable = true;
 859
 860         /*
 861          * make sure that once we start defragging an extent, we keep on
 862          * defragging it
 863          */
 864         if (start < *defrag_end)
 865                 return 1;
 866
 867         *skip = 0;
 868
 869         em = defrag_lookup_extent(inode, start);
 870         if (!em)
 871                 return 0;
 872
 873         /* this will cover holes, and inline extents */
 874         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
 875                 ret = 0;
 876                 goto out;
 877         }
 878
 879         next_mergeable = defrag_check_next_extent(inode, em);
 880
 881         /*
 882          * we hit a real extent, if it is big or the next extent is not a
 883          * real extent, don't bother defragging it
 884          */
 885         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
 886             (em->len >= thresh || !next_mergeable))
 887                 ret = 0;
 888 out:
 889         /*
 890          * last_len ends up being a counter of how many bytes we've defragged.
 891          * every time we choose not to defrag an extent, we reset *last_len
 892          * so that the next tiny extent will force a defrag.
 893          *
 894          * The end result of this is that tiny extents before a single big
 895          * extent will force at least part of that big extent to be defragged.
 896          */
 897         if (ret) {
 898                 *defrag_end = extent_map_end(em);
 899         } else {
 900                 *last_len = 0;
 901                 *skip = extent_map_end(em);
 902                 *defrag_end = 0;
 903         }
 904
 905         free_extent_map(em);
 906         return ret;
 907 }
 908
 909 /*
 910  * it doesn't do much good to defrag one or two pages
 911  * at a time.  This pulls in a nice chunk of pages
 912  * to COW and defrag.
 913  *
 914  * It also makes sure the delalloc code has enough
 915  * dirty data to avoid making new small extents as part
 916  * of the defrag
 917  *
 918  * It's a good idea to start RA on this range
 919  * before calling this.
 920  */
 921 static int cluster_pages_for_defrag(struct inode *inode,
 922                                     struct page **pages,
 923                                     unsigned long start_index,
 924                                     int num_pages)
 925 {
 926         unsigned long file_end;
 927         u64 isize = i_size_read(inode);
 928         u64 page_start;
 929         u64 page_end;
 930         u64 page_cnt;
 931         int ret;
 932         int i;
 933         int i_done;
 934         struct btrfs_ordered_extent *ordered;
 935         struct extent_state *cached_state = NULL;
 936         struct extent_io_tree *tree;
 937         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 938
 939         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
 940         if (!isize || start_index > file_end)
 941                 return 0;
 942
 943         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
 944
 945         ret = btrfs_delalloc_reserve_space(inode,
 946                                            page_cnt << PAGE_CACHE_SHIFT);
 947         if (ret)
 948                 return ret;
 949         i_done = 0;
 950         tree = &BTRFS_I(inode)->io_tree;
 951
 952         /* step one, lock all the pages */
 953         for (i = 0; i < page_cnt; i++) {
 954                 struct page *page;
 955 again:
 956                 page = find_or_create_page(inode->i_mapping,
 957                                            start_index + i, mask);
 958                 if (!page)
 959                         break;
 960
 961                 page_start = page_offset(page);
 962                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 963                 while (1) {
 964                         lock_extent(tree, page_start, page_end);
 965                         ordered = btrfs_lookup_ordered_extent(inode,
 966                                                               page_start);
 967                         unlock_extent(tree, page_start, page_end);
 968                         if (!ordered)
 969                                 break;
 970
 971                         unlock_page(page);
 972                         btrfs_start_ordered_extent(inode, ordered, 1);
 973                         btrfs_put_ordered_extent(ordered);
 974                         lock_page(page);
 975                         /*
 976                          * we unlocked the page above, so we need check if
 977                          * it was released or not.
 978                          */
 979                         if (page->mapping != inode->i_mapping) {
 980                                 unlock_page(page);
 981                                 page_cache_release(page);
 982                                 goto again;
 983                         }
 984                 }
 985
 986                 if (!PageUptodate(page)) {
 987                         btrfs_readpage(NULL, page);
 988                         lock_page(page);
 989                         if (!PageUptodate(page)) {
 990                                 unlock_page(page);
 991                                 page_cache_release(page);
 992                                 ret = -EIO;
 993                                 break;
 994                         }
 995                 }
 996
 997                 if (page->mapping != inode->i_mapping) {
 998                         unlock_page(page);
 999                         page_cache_release(page);
1000                         goto again;
1001                 }
1002
1003                 pages[i] = page;
1004                 i_done++;
1005         }
1006         if (!i_done || ret)
1007                 goto out;
1008
1009         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1010                 goto out;
1011
1012         /*
1013          * so now we have a nice long stream of locked
1014          * and up to date pages, lets wait on them
1015          */
1016         for (i = 0; i < i_done; i++)
1017                 wait_on_page_writeback(pages[i]);
1018
1019         page_start = page_offset(pages[0]);
1020         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1021
1022         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1023                          page_start, page_end - 1, 0, &cached_state);
1024         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1025                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1026                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1027                           &cached_state, GFP_NOFS);
1028
1029         if (i_done != page_cnt) {
1030                 spin_lock(&BTRFS_I(inode)->lock);
1031                 BTRFS_I(inode)->outstanding_extents++;
1032                 spin_unlock(&BTRFS_I(inode)->lock);
1033                 btrfs_delalloc_release_space(inode,
1034                                      (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1035         }
1036
1037
1038         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1039                           &cached_state, GFP_NOFS);
1040
1041         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1042                              page_start, page_end - 1, &cached_state,
1043                              GFP_NOFS);
1044
1045         for (i = 0; i < i_done; i++) {
1046                 clear_page_dirty_for_io(pages[i]);
1047                 ClearPageChecked(pages[i]);
1048                 set_page_extent_mapped(pages[i]);
1049                 set_page_dirty(pages[i]);
1050                 unlock_page(pages[i]);
1051                 page_cache_release(pages[i]);
1052         }
1053         return i_done;
1054 out:
1055         for (i = 0; i < i_done; i++) {
1056                 unlock_page(pages[i]);
1057                 page_cache_release(pages[i]);
1058         }
1059         btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1060         return ret;
1061
1062 }
1063
1064 int btrfs_defrag_file(struct inode *inode, struct file *file,
1065                       struct btrfs_ioctl_defrag_range_args *range,
1066                       u64 newer_than, unsigned long max_to_defrag)
1067 {
1068         struct btrfs_root *root = BTRFS_I(inode)->root;
1069         struct file_ra_state *ra = NULL;
1070         unsigned long last_index;
1071         u64 isize = i_size_read(inode);
1072         u64 last_len = 0;
1073         u64 skip = 0;
1074         u64 defrag_end = 0;
1075         u64 newer_off = range->start;
1076         unsigned long i;
1077         unsigned long ra_index = 0;
1078         int ret;
1079         int defrag_count = 0;
1080         int compress_type = BTRFS_COMPRESS_ZLIB;
1081         int extent_thresh = range->extent_thresh;
1082         int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1083         int cluster = max_cluster;
1084         u64 new_align = ~((u64)128 * 1024 - 1);
1085         struct page **pages = NULL;
1086
1087         if (extent_thresh == 0)
1088                 extent_thresh = 256 * 1024;
1089
1090         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1091                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1092                         return -EINVAL;
1093                 if (range->compress_type)
1094                         compress_type = range->compress_type;
1095         }
1096
1097         if (isize == 0)
1098                 return 0;
1099
1100         /*
1101          * if we were not given a file, allocate a readahead
1102          * context
1103          */
1104         if (!file) {
1105                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1106                 if (!ra)
1107                         return -ENOMEM;
1108                 file_ra_state_init(ra, inode->i_mapping);
1109         } else {
1110                 ra = &file->f_ra;
1111         }
1112
1113         pages = kmalloc(sizeof(struct page *) * max_cluster,
1114                         GFP_NOFS);
1115         if (!pages) {
1116                 ret = -ENOMEM;
1117                 goto out_ra;
1118         }
1119
1120         /* find the last page to defrag */
1121         if (range->start + range->len > range->start) {
1122                 last_index = min_t(u64, isize - 1,
1123                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1124         } else {
1125                 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1126         }
1127
1128         if (newer_than) {
1129                 ret = find_new_extents(root, inode, newer_than,
1130                                        &newer_off, 64 * 1024);
1131                 if (!ret) {
1132                         range->start = newer_off;
1133                         /*
1134                          * we always align our defrag to help keep
1135                          * the extents in the file evenly spaced
1136                          */
1137                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1138                 } else
1139                         goto out_ra;
1140         } else {
1141                 i = range->start >> PAGE_CACHE_SHIFT;
1142         }
1143         if (!max_to_defrag)
1144                 max_to_defrag = last_index + 1;
1145
1146         /*
1147          * make writeback starts from i, so the defrag range can be
1148          * written sequentially.
1149          */
1150         if (i < inode->i_mapping->writeback_index)
1151                 inode->i_mapping->writeback_index = i;
1152
1153         while (i <= last_index && defrag_count < max_to_defrag &&
1154                (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1155                 PAGE_CACHE_SHIFT)) {
1156                 /*
1157                  * make sure we stop running if someone unmounts
1158                  * the FS
1159                  */
1160                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1161                         break;
1162
1163                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1164                                          extent_thresh, &last_len, &skip,
1165                                          &defrag_end, range->flags &
1166                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1167                         unsigned long next;
1168                         /*
1169                          * the should_defrag function tells us how much to skip
1170                          * bump our counter by the suggested amount
1171                          */
1172                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1173                         i = max(i + 1, next);
1174                         continue;
1175                 }
1176
1177                 if (!newer_than) {
1178                         cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1179                                    PAGE_CACHE_SHIFT) - i;
1180                         cluster = min(cluster, max_cluster);
1181                 } else {
1182                         cluster = max_cluster;
1183                 }
1184
1185                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1186                         BTRFS_I(inode)->force_compress = compress_type;
1187
1188                 if (i + cluster > ra_index) {
1189                         ra_index = max(i, ra_index);
1190                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1191                                        cluster);
1192                         ra_index += max_cluster;
1193                 }
1194
1195                 mutex_lock(&inode->i_mutex);
1196                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1197                 if (ret < 0) {
1198                         mutex_unlock(&inode->i_mutex);
1199                         goto out_ra;
1200                 }
1201
1202                 defrag_count += ret;
1203                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1204                 mutex_unlock(&inode->i_mutex);
1205
1206                 if (newer_than) {
1207                         if (newer_off == (u64)-1)
1208                                 break;
1209
1210                         if (ret > 0)
1211                                 i += ret;
1212
1213                         newer_off = max(newer_off + 1,
1214                                         (u64)i << PAGE_CACHE_SHIFT);
1215
1216                         ret = find_new_extents(root, inode,
1217                                                newer_than, &newer_off,
1218                                                64 * 1024);
1219                         if (!ret) {
1220                                 range->start = newer_off;
1221                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1222                         } else {
1223                                 break;
1224                         }
1225                 } else {
1226                         if (ret > 0) {
1227                                 i += ret;
1228                                 last_len += ret << PAGE_CACHE_SHIFT;
1229                         } else {
1230                                 i++;
1231                                 last_len = 0;
1232                         }
1233                 }
1234         }
1235
1236         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1237                 filemap_flush(inode->i_mapping);
1238
1239         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1240                 /* the filemap_flush will queue IO into the worker threads, but
1241                  * we have to make sure the IO is actually started and that
1242                  * ordered extents get created before we return
1243                  */
1244                 atomic_inc(&root->fs_info->async_submit_draining);
1245                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1246                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1247                         wait_event(root->fs_info->async_submit_wait,
1248                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1249                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1250                 }
1251                 atomic_dec(&root->fs_info->async_submit_draining);
1252
1253                 mutex_lock(&inode->i_mutex);
1254                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1255                 mutex_unlock(&inode->i_mutex);
1256         }
1257
1258         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1259                 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1260         }
1261
1262         ret = defrag_count;
1263
1264 out_ra:
1265         if (!file)
1266                 kfree(ra);
1267         kfree(pages);
1268         return ret;
1269 }
1270
1271 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1272                                         void __user *arg)
1273 {
1274         u64 new_size;
1275         u64 old_size;
1276         u64 devid = 1;
1277         struct btrfs_ioctl_vol_args *vol_args;
1278         struct btrfs_trans_handle *trans;
1279         struct btrfs_device *device = NULL;
1280         char *sizestr;
1281         char *devstr = NULL;
1282         int ret = 0;
1283         int mod = 0;
1284
1285         if (root->fs_info->sb->s_flags & MS_RDONLY)
1286                 return -EROFS;
1287
1288         if (!capable(CAP_SYS_ADMIN))
1289                 return -EPERM;
1290
1291         mutex_lock(&root->fs_info->volume_mutex);
1292         if (root->fs_info->balance_ctl) {
1293                 printk(KERN_INFO "btrfs: balance in progress\n");
1294                 ret = -EINVAL;
1295                 goto out;
1296         }
1297
1298         vol_args = memdup_user(arg, sizeof(*vol_args));
1299         if (IS_ERR(vol_args)) {
1300                 ret = PTR_ERR(vol_args);
1301                 goto out;
1302         }
1303
1304         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1305
1306         sizestr = vol_args->name;
1307         devstr = strchr(sizestr, ':');
1308         if (devstr) {
1309                 char *end;
1310                 sizestr = devstr + 1;
1311                 *devstr = '\0';
1312                 devstr = vol_args->name;
1313                 devid = simple_strtoull(devstr, &end, 10);
1314                 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1315                        (unsigned long long)devid);
1316         }
1317         device = btrfs_find_device(root, devid, NULL, NULL);
1318         if (!device) {
1319                 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1320                        (unsigned long long)devid);
1321                 ret = -EINVAL;
1322                 goto out_free;
1323         }
1324         if (device->fs_devices && device->fs_devices->seeding) {
1325                 printk(KERN_INFO "btrfs: resizer unable to apply on "
1326                        "seeding device %llu\n",
1327                        (unsigned long long)devid);
1328                 ret = -EINVAL;
1329                 goto out_free;
1330         }
1331
1332         if (!strcmp(sizestr, "max"))
1333                 new_size = device->bdev->bd_inode->i_size;
1334         else {
1335                 if (sizestr[0] == '-') {
1336                         mod = -1;
1337                         sizestr++;
1338                 } else if (sizestr[0] == '+') {
1339                         mod = 1;
1340                         sizestr++;
1341                 }
1342                 new_size = memparse(sizestr, NULL);
1343                 if (new_size == 0) {
1344                         ret = -EINVAL;
1345                         goto out_free;
1346                 }
1347         }
1348
1349         old_size = device->total_bytes;
1350
1351         if (mod < 0) {
1352                 if (new_size > old_size) {
1353                         ret = -EINVAL;
1354                         goto out_free;
1355                 }
1356                 new_size = old_size - new_size;
1357         } else if (mod > 0) {
1358                 new_size = old_size + new_size;
1359         }
1360
1361         if (new_size < 256 * 1024 * 1024) {
1362                 ret = -EINVAL;
1363                 goto out_free;
1364         }
1365         if (new_size > device->bdev->bd_inode->i_size) {
1366                 ret = -EFBIG;
1367                 goto out_free;
1368         }
1369
1370         do_div(new_size, root->sectorsize);
1371         new_size *= root->sectorsize;
1372
1373         printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
1374                       rcu_str_deref(device->name),
1375                       (unsigned long long)new_size);
1376
1377         if (new_size > old_size) {
1378                 trans = btrfs_start_transaction(root, 0);
1379                 if (IS_ERR(trans)) {
1380                         ret = PTR_ERR(trans);
1381                         goto out_free;
1382                 }
1383                 ret = btrfs_grow_device(trans, device, new_size);
1384                 btrfs_commit_transaction(trans, root);
1385         } else if (new_size < old_size) {
1386                 ret = btrfs_shrink_device(device, new_size);
1387         }
1388
1389 out_free:
1390         kfree(vol_args);
1391 out:
1392         mutex_unlock(&root->fs_info->volume_mutex);
1393         return ret;
1394 }
1395
1396 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1397                                 char *name, unsigned long fd, int subvol,
1398                                 u64 *transid, bool readonly,
1399                                 struct btrfs_qgroup_inherit **inherit)
1400 {
1401         struct file *src_file;
1402         int namelen;
1403         int ret = 0;
1404
1405         ret = mnt_want_write_file(file);
1406         if (ret)
1407                 goto out;
1408
1409         namelen = strlen(name);
1410         if (strchr(name, '/')) {
1411                 ret = -EINVAL;
1412                 goto out_drop_write;
1413         }
1414
1415         if (name[0] == '.' &&
1416            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1417                 ret = -EEXIST;
1418                 goto out_drop_write;
1419         }
1420
1421         if (subvol) {
1422                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1423                                      NULL, transid, readonly, inherit);
1424         } else {
1425                 struct inode *src_inode;
1426                 src_file = fget(fd);
1427                 if (!src_file) {
1428                         ret = -EINVAL;
1429                         goto out_drop_write;
1430                 }
1431
1432                 src_inode = src_file->f_path.dentry->d_inode;
1433                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1434                         printk(KERN_INFO "btrfs: Snapshot src from "
1435                                "another FS\n");
1436                         ret = -EINVAL;
1437                         fput(src_file);
1438                         goto out_drop_write;
1439                 }
1440                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1441                                      BTRFS_I(src_inode)->root,
1442                                      transid, readonly, inherit);
1443                 fput(src_file);
1444         }
1445 out_drop_write:
1446         mnt_drop_write_file(file);
1447 out:
1448         return ret;
1449 }
1450
1451 static noinline int btrfs_ioctl_snap_create(struct file *file,
1452                                             void __user *arg, int subvol)
1453 {
1454         struct btrfs_ioctl_vol_args *vol_args;
1455         int ret;
1456
1457         vol_args = memdup_user(arg, sizeof(*vol_args));
1458         if (IS_ERR(vol_args))
1459                 return PTR_ERR(vol_args);
1460         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1461
1462         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1463                                               vol_args->fd, subvol,
1464                                               NULL, false, NULL);
1465
1466         kfree(vol_args);
1467         return ret;
1468 }
1469
1470 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1471                                                void __user *arg, int subvol)
1472 {
1473         struct btrfs_ioctl_vol_args_v2 *vol_args;
1474         int ret;
1475         u64 transid = 0;
1476         u64 *ptr = NULL;
1477         bool readonly = false;
1478         struct btrfs_qgroup_inherit *inherit = NULL;
1479
1480         vol_args = memdup_user(arg, sizeof(*vol_args));
1481         if (IS_ERR(vol_args))
1482                 return PTR_ERR(vol_args);
1483         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1484
1485         if (vol_args->flags &
1486             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1487               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1488                 ret = -EOPNOTSUPP;
1489                 goto out;
1490         }
1491
1492         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1493                 ptr = &transid;
1494         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1495                 readonly = true;
1496         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1497                 if (vol_args->size > PAGE_CACHE_SIZE) {
1498                         ret = -EINVAL;
1499                         goto out;
1500                 }
1501                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1502                 if (IS_ERR(inherit)) {
1503                         ret = PTR_ERR(inherit);
1504                         goto out;
1505                 }
1506         }
1507
1508         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1509                                               vol_args->fd, subvol, ptr,
1510                                               readonly, &inherit);
1511
1512         if (ret == 0 && ptr &&
1513             copy_to_user(arg +
1514                          offsetof(struct btrfs_ioctl_vol_args_v2,
1515                                   transid), ptr, sizeof(*ptr)))
1516                 ret = -EFAULT;
1517 out:
1518         kfree(vol_args);
1519         kfree(inherit);
1520         return ret;
1521 }
1522
1523 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1524                                                 void __user *arg)
1525 {
1526         struct inode *inode = fdentry(file)->d_inode;
1527         struct btrfs_root *root = BTRFS_I(inode)->root;
1528         int ret = 0;
1529         u64 flags = 0;
1530
1531         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1532                 return -EINVAL;
1533
1534         down_read(&root->fs_info->subvol_sem);
1535         if (btrfs_root_readonly(root))
1536                 flags |= BTRFS_SUBVOL_RDONLY;
1537         up_read(&root->fs_info->subvol_sem);
1538
1539         if (copy_to_user(arg, &flags, sizeof(flags)))
1540                 ret = -EFAULT;
1541
1542         return ret;
1543 }
1544
1545 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1546                                               void __user *arg)
1547 {
1548         struct inode *inode = fdentry(file)->d_inode;
1549         struct btrfs_root *root = BTRFS_I(inode)->root;
1550         struct btrfs_trans_handle *trans;
1551         u64 root_flags;
1552         u64 flags;
1553         int ret = 0;
1554
1555         ret = mnt_want_write_file(file);
1556         if (ret)
1557                 goto out;
1558
1559         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1560                 ret = -EINVAL;
1561                 goto out_drop_write;
1562         }
1563
1564         if (copy_from_user(&flags, arg, sizeof(flags))) {
1565                 ret = -EFAULT;
1566                 goto out_drop_write;
1567         }
1568
1569         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1570                 ret = -EINVAL;
1571                 goto out_drop_write;
1572         }
1573
1574         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1575                 ret = -EOPNOTSUPP;
1576                 goto out_drop_write;
1577         }
1578
1579         if (!inode_owner_or_capable(inode)) {
1580                 ret = -EACCES;
1581                 goto out_drop_write;
1582         }
1583
1584         down_write(&root->fs_info->subvol_sem);
1585
1586         /* nothing to do */
1587         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1588                 goto out_drop_sem;
1589
1590         root_flags = btrfs_root_flags(&root->root_item);
1591         if (flags & BTRFS_SUBVOL_RDONLY)
1592                 btrfs_set_root_flags(&root->root_item,
1593                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1594         else
1595                 btrfs_set_root_flags(&root->root_item,
1596                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1597
1598         trans = btrfs_start_transaction(root, 1);
1599         if (IS_ERR(trans)) {
1600                 ret = PTR_ERR(trans);
1601                 goto out_reset;
1602         }
1603
1604         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1605                                 &root->root_key, &root->root_item);
1606
1607         btrfs_commit_transaction(trans, root);
1608 out_reset:
1609         if (ret)
1610                 btrfs_set_root_flags(&root->root_item, root_flags);
1611 out_drop_sem:
1612         up_write(&root->fs_info->subvol_sem);
1613 out_drop_write:
1614         mnt_drop_write_file(file);
1615 out:
1616         return ret;
1617 }
1618
1619 /*
1620  * helper to check if the subvolume references other subvolumes
1621  */
1622 static noinline int may_destroy_subvol(struct btrfs_root *root)
1623 {
1624         struct btrfs_path *path;
1625         struct btrfs_key key;
1626         int ret;
1627
1628         path = btrfs_alloc_path();
1629         if (!path)
1630                 return -ENOMEM;
1631
1632         key.objectid = root->root_key.objectid;
1633         key.type = BTRFS_ROOT_REF_KEY;
1634         key.offset = (u64)-1;
1635
1636         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1637                                 &key, path, 0, 0);
1638         if (ret < 0)
1639                 goto out;
1640         BUG_ON(ret == 0);
1641
1642         ret = 0;
1643         if (path->slots[0] > 0) {
1644                 path->slots[0]--;
1645                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1646                 if (key.objectid == root->root_key.objectid &&
1647                     key.type == BTRFS_ROOT_REF_KEY)
1648                         ret = -ENOTEMPTY;
1649         }
1650 out:
1651         btrfs_free_path(path);
1652         return ret;
1653 }
1654
1655 static noinline int key_in_sk(struct btrfs_key *key,
1656                               struct btrfs_ioctl_search_key *sk)
1657 {
1658         struct btrfs_key test;
1659         int ret;
1660
1661         test.objectid = sk->min_objectid;
1662         test.type = sk->min_type;
1663         test.offset = sk->min_offset;
1664
1665         ret = btrfs_comp_cpu_keys(key, &test);
1666         if (ret < 0)
1667                 return 0;
1668
1669         test.objectid = sk->max_objectid;
1670         test.type = sk->max_type;
1671         test.offset = sk->max_offset;
1672
1673         ret = btrfs_comp_cpu_keys(key, &test);
1674         if (ret > 0)
1675                 return 0;
1676         return 1;
1677 }
1678
1679 static noinline int copy_to_sk(struct btrfs_root *root,
1680                                struct btrfs_path *path,
1681                                struct btrfs_key *key,
1682                                struct btrfs_ioctl_search_key *sk,
1683                                char *buf,
1684                                unsigned long *sk_offset,
1685                                int *num_found)
1686 {
1687         u64 found_transid;
1688         struct extent_buffer *leaf;
1689         struct btrfs_ioctl_search_header sh;
1690         unsigned long item_off;
1691         unsigned long item_len;
1692         int nritems;
1693         int i;
1694         int slot;
1695         int ret = 0;
1696
1697         leaf = path->nodes[0];
1698         slot = path->slots[0];
1699         nritems = btrfs_header_nritems(leaf);
1700
1701         if (btrfs_header_generation(leaf) > sk->max_transid) {
1702                 i = nritems;
1703                 goto advance_key;
1704         }
1705         found_transid = btrfs_header_generation(leaf);
1706
1707         for (i = slot; i < nritems; i++) {
1708                 item_off = btrfs_item_ptr_offset(leaf, i);
1709                 item_len = btrfs_item_size_nr(leaf, i);
1710
1711                 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1712                         item_len = 0;
1713
1714                 if (sizeof(sh) + item_len + *sk_offset >
1715                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1716                         ret = 1;
1717                         goto overflow;
1718                 }
1719
1720                 btrfs_item_key_to_cpu(leaf, key, i);
1721                 if (!key_in_sk(key, sk))
1722                         continue;
1723
1724                 sh.objectid = key->objectid;
1725                 sh.offset = key->offset;
1726                 sh.type = key->type;
1727                 sh.len = item_len;
1728                 sh.transid = found_transid;
1729
1730                 /* copy search result header */
1731                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1732                 *sk_offset += sizeof(sh);
1733
1734                 if (item_len) {
1735                         char *p = buf + *sk_offset;
1736                         /* copy the item */
1737                         read_extent_buffer(leaf, p,
1738                                            item_off, item_len);
1739                         *sk_offset += item_len;
1740                 }
1741                 (*num_found)++;
1742
1743                 if (*num_found >= sk->nr_items)
1744                         break;
1745         }
1746 advance_key:
1747         ret = 0;
1748         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1749                 key->offset++;
1750         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1751                 key->offset = 0;
1752                 key->type++;
1753         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1754                 key->offset = 0;
1755                 key->type = 0;
1756                 key->objectid++;
1757         } else
1758                 ret = 1;
1759 overflow:
1760         return ret;
1761 }
1762
1763 static noinline int search_ioctl(struct inode *inode,
1764                                  struct btrfs_ioctl_search_args *args)
1765 {
1766         struct btrfs_root *root;
1767         struct btrfs_key key;
1768         struct btrfs_key max_key;
1769         struct btrfs_path *path;
1770         struct btrfs_ioctl_search_key *sk = &args->key;
1771         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1772         int ret;
1773         int num_found = 0;
1774         unsigned long sk_offset = 0;
1775
1776         path = btrfs_alloc_path();
1777         if (!path)
1778                 return -ENOMEM;
1779
1780         if (sk->tree_id == 0) {
1781                 /* search the root of the inode that was passed */
1782                 root = BTRFS_I(inode)->root;
1783         } else {
1784                 key.objectid = sk->tree_id;
1785                 key.type = BTRFS_ROOT_ITEM_KEY;
1786                 key.offset = (u64)-1;
1787                 root = btrfs_read_fs_root_no_name(info, &key);
1788                 if (IS_ERR(root)) {
1789                         printk(KERN_ERR "could not find root %llu\n",
1790                                sk->tree_id);
1791                         btrfs_free_path(path);
1792                         return -ENOENT;
1793                 }
1794         }
1795
1796         key.objectid = sk->min_objectid;
1797         key.type = sk->min_type;
1798         key.offset = sk->min_offset;
1799
1800         max_key.objectid = sk->max_objectid;
1801         max_key.type = sk->max_type;
1802         max_key.offset = sk->max_offset;
1803
1804         path->keep_locks = 1;
1805
1806         while(1) {
1807                 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1808                                            sk->min_transid);
1809                 if (ret != 0) {
1810                         if (ret > 0)
1811                                 ret = 0;
1812                         goto err;
1813                 }
1814                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1815                                  &sk_offset, &num_found);
1816                 btrfs_release_path(path);
1817                 if (ret || num_found >= sk->nr_items)
1818                         break;
1819
1820         }
1821         ret = 0;
1822 err:
1823         sk->nr_items = num_found;
1824         btrfs_free_path(path);
1825         return ret;
1826 }
1827
1828 static noinline int btrfs_ioctl_tree_search(struct file *file,
1829                                            void __user *argp)
1830 {
1831          struct btrfs_ioctl_search_args *args;
1832          struct inode *inode;
1833          int ret;
1834
1835         if (!capable(CAP_SYS_ADMIN))
1836                 return -EPERM;
1837
1838         args = memdup_user(argp, sizeof(*args));
1839         if (IS_ERR(args))
1840                 return PTR_ERR(args);
1841
1842         inode = fdentry(file)->d_inode;
1843         ret = search_ioctl(inode, args);
1844         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1845                 ret = -EFAULT;
1846         kfree(args);
1847         return ret;
1848 }
1849
1850 /*
1851  * Search INODE_REFs to identify path name of 'dirid' directory
1852  * in a 'tree_id' tree. and sets path name to 'name'.
1853  */
1854 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1855                                 u64 tree_id, u64 dirid, char *name)
1856 {
1857         struct btrfs_root *root;
1858         struct btrfs_key key;
1859         char *ptr;
1860         int ret = -1;
1861         int slot;
1862         int len;
1863         int total_len = 0;
1864         struct btrfs_inode_ref *iref;
1865         struct extent_buffer *l;
1866         struct btrfs_path *path;
1867
1868         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1869                 name[0]='\0';
1870                 return 0;
1871         }
1872
1873         path = btrfs_alloc_path();
1874         if (!path)
1875                 return -ENOMEM;
1876
1877         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1878
1879         key.objectid = tree_id;
1880         key.type = BTRFS_ROOT_ITEM_KEY;
1881         key.offset = (u64)-1;
1882         root = btrfs_read_fs_root_no_name(info, &key);
1883         if (IS_ERR(root)) {
1884                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1885                 ret = -ENOENT;
1886                 goto out;
1887         }
1888
1889         key.objectid = dirid;
1890         key.type = BTRFS_INODE_REF_KEY;
1891         key.offset = (u64)-1;
1892
1893         while(1) {
1894                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1895                 if (ret < 0)
1896                         goto out;
1897
1898                 l = path->nodes[0];
1899                 slot = path->slots[0];
1900                 if (ret > 0 && slot > 0)
1901                         slot--;
1902                 btrfs_item_key_to_cpu(l, &key, slot);
1903
1904                 if (ret > 0 && (key.objectid != dirid ||
1905                                 key.type != BTRFS_INODE_REF_KEY)) {
1906                         ret = -ENOENT;
1907                         goto out;
1908                 }
1909
1910                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1911                 len = btrfs_inode_ref_name_len(l, iref);
1912                 ptr -= len + 1;
1913                 total_len += len + 1;
1914                 if (ptr < name)
1915                         goto out;
1916
1917                 *(ptr + len) = '/';
1918                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1919
1920                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1921                         break;
1922
1923                 btrfs_release_path(path);
1924                 key.objectid = key.offset;
1925                 key.offset = (u64)-1;
1926                 dirid = key.objectid;
1927         }
1928         if (ptr < name)
1929                 goto out;
1930         memmove(name, ptr, total_len);
1931         name[total_len]='\0';
1932         ret = 0;
1933 out:
1934         btrfs_free_path(path);
1935         return ret;
1936 }
1937
1938 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1939                                            void __user *argp)
1940 {
1941          struct btrfs_ioctl_ino_lookup_args *args;
1942          struct inode *inode;
1943          int ret;
1944
1945         if (!capable(CAP_SYS_ADMIN))
1946                 return -EPERM;
1947
1948         args = memdup_user(argp, sizeof(*args));
1949         if (IS_ERR(args))
1950                 return PTR_ERR(args);
1951
1952         inode = fdentry(file)->d_inode;
1953
1954         if (args->treeid == 0)
1955                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1956
1957         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1958                                         args->treeid, args->objectid,
1959                                         args->name);
1960
1961         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1962                 ret = -EFAULT;
1963
1964         kfree(args);
1965         return ret;
1966 }
1967
1968 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1969                                              void __user *arg)
1970 {
1971         struct dentry *parent = fdentry(file);
1972         struct dentry *dentry;
1973         struct inode *dir = parent->d_inode;
1974         struct inode *inode;
1975         struct btrfs_root *root = BTRFS_I(dir)->root;
1976         struct btrfs_root *dest = NULL;
1977         struct btrfs_ioctl_vol_args *vol_args;
1978         struct btrfs_trans_handle *trans;
1979         int namelen;
1980         int ret;
1981         int err = 0;
1982
1983         vol_args = memdup_user(arg, sizeof(*vol_args));
1984         if (IS_ERR(vol_args))
1985                 return PTR_ERR(vol_args);
1986
1987         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1988         namelen = strlen(vol_args->name);
1989         if (strchr(vol_args->name, '/') ||
1990             strncmp(vol_args->name, "..", namelen) == 0) {
1991                 err = -EINVAL;
1992                 goto out;
1993         }
1994
1995         err = mnt_want_write_file(file);
1996         if (err)
1997                 goto out;
1998
1999         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
2000         dentry = lookup_one_len(vol_args->name, parent, namelen);
2001         if (IS_ERR(dentry)) {
2002                 err = PTR_ERR(dentry);
2003                 goto out_unlock_dir;
2004         }
2005
2006         if (!dentry->d_inode) {
2007                 err = -ENOENT;
2008                 goto out_dput;
2009         }
2010
2011         inode = dentry->d_inode;
2012         dest = BTRFS_I(inode)->root;
2013         if (!capable(CAP_SYS_ADMIN)){
2014                 /*
2015                  * Regular user.  Only allow this with a special mount
2016                  * option, when the user has write+exec access to the
2017                  * subvol root, and when rmdir(2) would have been
2018                  * allowed.
2019                  *
2020                  * Note that this is _not_ check that the subvol is
2021                  * empty or doesn't contain data that we wouldn't
2022                  * otherwise be able to delete.
2023                  *
2024                  * Users who want to delete empty subvols should try
2025                  * rmdir(2).
2026                  */
2027                 err = -EPERM;
2028                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2029                         goto out_dput;
2030
2031                 /*
2032                  * Do not allow deletion if the parent dir is the same
2033                  * as the dir to be deleted.  That means the ioctl
2034                  * must be called on the dentry referencing the root
2035                  * of the subvol, not a random directory contained
2036                  * within it.
2037                  */
2038                 err = -EINVAL;
2039                 if (root == dest)
2040                         goto out_dput;
2041
2042                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2043                 if (err)
2044                         goto out_dput;
2045
2046                 /* check if subvolume may be deleted by a non-root user */
2047                 err = btrfs_may_delete(dir, dentry, 1);
2048                 if (err)
2049                         goto out_dput;
2050         }
2051
2052         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2053                 err = -EINVAL;
2054                 goto out_dput;
2055         }
2056
2057         mutex_lock(&inode->i_mutex);
2058         err = d_invalidate(dentry);
2059         if (err)
2060                 goto out_unlock;
2061
2062         down_write(&root->fs_info->subvol_sem);
2063
2064         err = may_destroy_subvol(dest);
2065         if (err)
2066                 goto out_up_write;
2067
2068         trans = btrfs_start_transaction(root, 0);
2069         if (IS_ERR(trans)) {
2070                 err = PTR_ERR(trans);
2071                 goto out_up_write;
2072         }
2073         trans->block_rsv = &root->fs_info->global_block_rsv;
2074
2075         ret = btrfs_unlink_subvol(trans, root, dir,
2076                                 dest->root_key.objectid,
2077                                 dentry->d_name.name,
2078                                 dentry->d_name.len);
2079         if (ret) {
2080                 err = ret;
2081                 btrfs_abort_transaction(trans, root, ret);
2082                 goto out_end_trans;
2083         }
2084
2085         btrfs_record_root_in_trans(trans, dest);
2086
2087         memset(&dest->root_item.drop_progress, 0,
2088                 sizeof(dest->root_item.drop_progress));
2089         dest->root_item.drop_level = 0;
2090         btrfs_set_root_refs(&dest->root_item, 0);
2091
2092         if (!xchg(&dest->orphan_item_inserted, 1)) {
2093                 ret = btrfs_insert_orphan_item(trans,
2094                                         root->fs_info->tree_root,
2095                                         dest->root_key.objectid);
2096                 if (ret) {
2097                         btrfs_abort_transaction(trans, root, ret);
2098                         err = ret;
2099                         goto out_end_trans;
2100                 }
2101         }
2102 out_end_trans:
2103         ret = btrfs_end_transaction(trans, root);
2104         if (ret && !err)
2105                 err = ret;
2106         inode->i_flags |= S_DEAD;
2107 out_up_write:
2108         up_write(&root->fs_info->subvol_sem);
2109 out_unlock:
2110         mutex_unlock(&inode->i_mutex);
2111         if (!err) {
2112                 shrink_dcache_sb(root->fs_info->sb);
2113                 btrfs_invalidate_inodes(dest);
2114                 d_delete(dentry);
2115         }
2116 out_dput:
2117         dput(dentry);
2118 out_unlock_dir:
2119         mutex_unlock(&dir->i_mutex);
2120         mnt_drop_write_file(file);
2121 out:
2122         kfree(vol_args);
2123         return err;
2124 }
2125
2126 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2127 {
2128         struct inode *inode = fdentry(file)->d_inode;
2129         struct btrfs_root *root = BTRFS_I(inode)->root;
2130         struct btrfs_ioctl_defrag_range_args *range;
2131         int ret;
2132
2133         if (btrfs_root_readonly(root))
2134                 return -EROFS;
2135
2136         ret = mnt_want_write_file(file);
2137         if (ret)
2138                 return ret;
2139
2140         switch (inode->i_mode & S_IFMT) {
2141         case S_IFDIR:
2142                 if (!capable(CAP_SYS_ADMIN)) {
2143                         ret = -EPERM;
2144                         goto out;
2145                 }
2146                 ret = btrfs_defrag_root(root, 0);
2147                 if (ret)
2148                         goto out;
2149                 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2150                 break;
2151         case S_IFREG:
2152                 if (!(file->f_mode & FMODE_WRITE)) {
2153                         ret = -EINVAL;
2154                         goto out;
2155                 }
2156
2157                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2158                 if (!range) {
2159                         ret = -ENOMEM;
2160                         goto out;
2161                 }
2162
2163                 if (argp) {
2164                         if (copy_from_user(range, argp,
2165                                            sizeof(*range))) {
2166                                 ret = -EFAULT;
2167                                 kfree(range);
2168                                 goto out;
2169                         }
2170                         /* compression requires us to start the IO */
2171                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2172                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2173                                 range->extent_thresh = (u32)-1;
2174                         }
2175                 } else {
2176                         /* the rest are all set to zero by kzalloc */
2177                         range->len = (u64)-1;
2178                 }
2179                 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2180                                         range, 0, 0);
2181                 if (ret > 0)
2182                         ret = 0;
2183                 kfree(range);
2184                 break;
2185         default:
2186                 ret = -EINVAL;
2187         }
2188 out:
2189         mnt_drop_write_file(file);
2190         return ret;
2191 }
2192
2193 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2194 {
2195         struct btrfs_ioctl_vol_args *vol_args;
2196         int ret;
2197
2198         if (!capable(CAP_SYS_ADMIN))
2199                 return -EPERM;
2200
2201         mutex_lock(&root->fs_info->volume_mutex);
2202         if (root->fs_info->balance_ctl) {
2203                 printk(KERN_INFO "btrfs: balance in progress\n");
2204                 ret = -EINVAL;
2205                 goto out;
2206         }
2207
2208         vol_args = memdup_user(arg, sizeof(*vol_args));
2209         if (IS_ERR(vol_args)) {
2210                 ret = PTR_ERR(vol_args);
2211                 goto out;
2212         }
2213
2214         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2215         ret = btrfs_init_new_device(root, vol_args->name);
2216
2217         kfree(vol_args);
2218 out:
2219         mutex_unlock(&root->fs_info->volume_mutex);
2220         return ret;
2221 }
2222
2223 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2224 {
2225         struct btrfs_ioctl_vol_args *vol_args;
2226         int ret;
2227
2228         if (!capable(CAP_SYS_ADMIN))
2229                 return -EPERM;
2230
2231         if (root->fs_info->sb->s_flags & MS_RDONLY)
2232                 return -EROFS;
2233
2234         mutex_lock(&root->fs_info->volume_mutex);
2235         if (root->fs_info->balance_ctl) {
2236                 printk(KERN_INFO "btrfs: balance in progress\n");
2237                 ret = -EINVAL;
2238                 goto out;
2239         }
2240
2241         vol_args = memdup_user(arg, sizeof(*vol_args));
2242         if (IS_ERR(vol_args)) {
2243                 ret = PTR_ERR(vol_args);
2244                 goto out;
2245         }
2246
2247         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2248         ret = btrfs_rm_device(root, vol_args->name);
2249
2250         kfree(vol_args);
2251 out:
2252         mutex_unlock(&root->fs_info->volume_mutex);
2253         return ret;
2254 }
2255
2256 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2257 {
2258         struct btrfs_ioctl_fs_info_args *fi_args;
2259         struct btrfs_device *device;
2260         struct btrfs_device *next;
2261         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2262         int ret = 0;
2263
2264         if (!capable(CAP_SYS_ADMIN))
2265                 return -EPERM;
2266
2267         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2268         if (!fi_args)
2269                 return -ENOMEM;
2270
2271         fi_args->num_devices = fs_devices->num_devices;
2272         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2273
2274         mutex_lock(&fs_devices->device_list_mutex);
2275         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2276                 if (device->devid > fi_args->max_id)
2277                         fi_args->max_id = device->devid;
2278         }
2279         mutex_unlock(&fs_devices->device_list_mutex);
2280
2281         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2282                 ret = -EFAULT;
2283
2284         kfree(fi_args);
2285         return ret;
2286 }
2287
2288 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2289 {
2290         struct btrfs_ioctl_dev_info_args *di_args;
2291         struct btrfs_device *dev;
2292         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2293         int ret = 0;
2294         char *s_uuid = NULL;
2295         char empty_uuid[BTRFS_UUID_SIZE] = {0};
2296
2297         if (!capable(CAP_SYS_ADMIN))
2298                 return -EPERM;
2299
2300         di_args = memdup_user(arg, sizeof(*di_args));
2301         if (IS_ERR(di_args))
2302                 return PTR_ERR(di_args);
2303
2304         if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2305                 s_uuid = di_args->uuid;
2306
2307         mutex_lock(&fs_devices->device_list_mutex);
2308         dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2309         mutex_unlock(&fs_devices->device_list_mutex);
2310
2311         if (!dev) {
2312                 ret = -ENODEV;
2313                 goto out;
2314         }
2315
2316         di_args->devid = dev->devid;
2317         di_args->bytes_used = dev->bytes_used;
2318         di_args->total_bytes = dev->total_bytes;
2319         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2320         if (dev->name) {
2321                 struct rcu_string *name;
2322
2323                 rcu_read_lock();
2324                 name = rcu_dereference(dev->name);
2325                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2326                 rcu_read_unlock();
2327                 di_args->path[sizeof(di_args->path) - 1] = 0;
2328         } else {
2329                 di_args->path[0] = '\0';
2330         }
2331
2332 out:
2333         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2334                 ret = -EFAULT;
2335
2336         kfree(di_args);
2337         return ret;
2338 }
2339
2340 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2341                                        u64 off, u64 olen, u64 destoff)
2342 {
2343         struct inode *inode = fdentry(file)->d_inode;
2344         struct btrfs_root *root = BTRFS_I(inode)->root;
2345         struct file *src_file;
2346         struct inode *src;
2347         struct btrfs_trans_handle *trans;
2348         struct btrfs_path *path;
2349         struct extent_buffer *leaf;
2350         char *buf;
2351         struct btrfs_key key;
2352         u32 nritems;
2353         int slot;
2354         int ret;
2355         u64 len = olen;
2356         u64 bs = root->fs_info->sb->s_blocksize;
2357
2358         /*
2359          * TODO:
2360          * - split compressed inline extents.  annoying: we need to
2361          *   decompress into destination's address_space (the file offset
2362          *   may change, so source mapping won't do), then recompress (or
2363          *   otherwise reinsert) a subrange.
2364          * - allow ranges within the same file to be cloned (provided
2365          *   they don't overlap)?
2366          */
2367
2368         /* the destination must be opened for writing */
2369         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2370                 return -EINVAL;
2371
2372         if (btrfs_root_readonly(root))
2373                 return -EROFS;
2374
2375         ret = mnt_want_write_file(file);
2376         if (ret)
2377                 return ret;
2378
2379         src_file = fget(srcfd);
2380         if (!src_file) {
2381                 ret = -EBADF;
2382                 goto out_drop_write;
2383         }
2384
2385         ret = -EXDEV;
2386         if (src_file->f_path.mnt != file->f_path.mnt)
2387                 goto out_fput;
2388
2389         src = src_file->f_dentry->d_inode;
2390
2391         ret = -EINVAL;
2392         if (src == inode)
2393                 goto out_fput;
2394
2395         /* the src must be open for reading */
2396         if (!(src_file->f_mode & FMODE_READ))
2397                 goto out_fput;
2398
2399         /* don't make the dst file partly checksummed */
2400         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2401             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2402                 goto out_fput;
2403
2404         ret = -EISDIR;
2405         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2406                 goto out_fput;
2407
2408         ret = -EXDEV;
2409         if (src->i_sb != inode->i_sb)
2410                 goto out_fput;
2411
2412         ret = -ENOMEM;
2413         buf = vmalloc(btrfs_level_size(root, 0));
2414         if (!buf)
2415                 goto out_fput;
2416
2417         path = btrfs_alloc_path();
2418         if (!path) {
2419                 vfree(buf);
2420                 goto out_fput;
2421         }
2422         path->reada = 2;
2423
2424         if (inode < src) {
2425                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2426                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2427         } else {
2428                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2429                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2430         }
2431
2432         /* determine range to clone */
2433         ret = -EINVAL;
2434         if (off + len > src->i_size || off + len < off)
2435                 goto out_unlock;
2436         if (len == 0)
2437                 olen = len = src->i_size - off;
2438         /* if we extend to eof, continue to block boundary */
2439         if (off + len == src->i_size)
2440                 len = ALIGN(src->i_size, bs) - off;
2441
2442         /* verify the end result is block aligned */
2443         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2444             !IS_ALIGNED(destoff, bs))
2445                 goto out_unlock;
2446
2447         if (destoff > inode->i_size) {
2448                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2449                 if (ret)
2450                         goto out_unlock;
2451         }
2452
2453         /* truncate page cache pages from target inode range */
2454         truncate_inode_pages_range(&inode->i_data, destoff,
2455                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
2456
2457         /* do any pending delalloc/csum calc on src, one way or
2458            another, and lock file content */
2459         while (1) {
2460                 struct btrfs_ordered_extent *ordered;
2461                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2462                 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2463                 if (!ordered &&
2464                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2465                                    EXTENT_DELALLOC, 0, NULL))
2466                         break;
2467                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2468                 if (ordered)
2469                         btrfs_put_ordered_extent(ordered);
2470                 btrfs_wait_ordered_range(src, off, len);
2471         }
2472
2473         /* clone data */
2474         key.objectid = btrfs_ino(src);
2475         key.type = BTRFS_EXTENT_DATA_KEY;
2476         key.offset = 0;
2477
2478         while (1) {
2479                 /*
2480                  * note the key will change type as we walk through the
2481                  * tree.
2482                  */
2483                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
2484                                 0, 0);
2485                 if (ret < 0)
2486                         goto out;
2487
2488                 nritems = btrfs_header_nritems(path->nodes[0]);
2489                 if (path->slots[0] >= nritems) {
2490                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
2491                         if (ret < 0)
2492                                 goto out;
2493                         if (ret > 0)
2494                                 break;
2495                         nritems = btrfs_header_nritems(path->nodes[0]);
2496                 }
2497                 leaf = path->nodes[0];
2498                 slot = path->slots[0];
2499
2500                 btrfs_item_key_to_cpu(leaf, &key, slot);
2501                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2502                     key.objectid != btrfs_ino(src))
2503                         break;
2504
2505                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2506                         struct btrfs_file_extent_item *extent;
2507                         int type;
2508                         u32 size;
2509                         struct btrfs_key new_key;
2510                         u64 disko = 0, diskl = 0;
2511                         u64 datao = 0, datal = 0;
2512                         u8 comp;
2513                         u64 endoff;
2514
2515                         size = btrfs_item_size_nr(leaf, slot);
2516                         read_extent_buffer(leaf, buf,
2517                                            btrfs_item_ptr_offset(leaf, slot),
2518                                            size);
2519
2520                         extent = btrfs_item_ptr(leaf, slot,
2521                                                 struct btrfs_file_extent_item);
2522                         comp = btrfs_file_extent_compression(leaf, extent);
2523                         type = btrfs_file_extent_type(leaf, extent);
2524                         if (type == BTRFS_FILE_EXTENT_REG ||
2525                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2526                                 disko = btrfs_file_extent_disk_bytenr(leaf,
2527                                                                       extent);
2528                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2529                                                                  extent);
2530                                 datao = btrfs_file_extent_offset(leaf, extent);
2531                                 datal = btrfs_file_extent_num_bytes(leaf,
2532                                                                     extent);
2533                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2534                                 /* take upper bound, may be compressed */
2535                                 datal = btrfs_file_extent_ram_bytes(leaf,
2536                                                                     extent);
2537                         }
2538                         btrfs_release_path(path);
2539
2540                         if (key.offset + datal <= off ||
2541                             key.offset >= off+len)
2542                                 goto next;
2543
2544                         memcpy(&new_key, &key, sizeof(new_key));
2545                         new_key.objectid = btrfs_ino(inode);
2546                         if (off <= key.offset)
2547                                 new_key.offset = key.offset + destoff - off;
2548                         else
2549                                 new_key.offset = destoff;
2550
2551                         /*
2552                          * 1 - adjusting old extent (we may have to split it)
2553                          * 1 - add new extent
2554                          * 1 - inode update
2555                          */
2556                         trans = btrfs_start_transaction(root, 3);
2557                         if (IS_ERR(trans)) {
2558                                 ret = PTR_ERR(trans);
2559                                 goto out;
2560                         }
2561
2562                         if (type == BTRFS_FILE_EXTENT_REG ||
2563                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2564                                 /*
2565                                  *    a  | --- range to clone ---|  b
2566                                  * | ------------- extent ------------- |
2567                                  */
2568
2569                                 /* substract range b */
2570                                 if (key.offset + datal > off + len)
2571                                         datal = off + len - key.offset;
2572
2573                                 /* substract range a */
2574                                 if (off > key.offset) {
2575                                         datao += off - key.offset;
2576                                         datal -= off - key.offset;
2577                                 }
2578
2579                                 ret = btrfs_drop_extents(trans, root, inode,
2580                                                          new_key.offset,
2581                                                          new_key.offset + datal,
2582                                                          1);
2583                                 if (ret) {
2584                                         btrfs_abort_transaction(trans, root,
2585                                                                 ret);
2586                                         btrfs_end_transaction(trans, root);
2587                                         goto out;
2588                                 }
2589
2590                                 ret = btrfs_insert_empty_item(trans, root, path,
2591                                                               &new_key, size);
2592                                 if (ret) {
2593                                         btrfs_abort_transaction(trans, root,
2594                                                                 ret);
2595                                         btrfs_end_transaction(trans, root);
2596                                         goto out;
2597                                 }
2598
2599                                 leaf = path->nodes[0];
2600                                 slot = path->slots[0];
2601                                 write_extent_buffer(leaf, buf,
2602                                             btrfs_item_ptr_offset(leaf, slot),
2603                                             size);
2604
2605                                 extent = btrfs_item_ptr(leaf, slot,
2606                                                 struct btrfs_file_extent_item);
2607
2608                                 /* disko == 0 means it's a hole */
2609                                 if (!disko)
2610                                         datao = 0;
2611
2612                                 btrfs_set_file_extent_offset(leaf, extent,
2613                                                              datao);
2614                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2615                                                                 datal);
2616                                 if (disko) {
2617                                         inode_add_bytes(inode, datal);
2618                                         ret = btrfs_inc_extent_ref(trans, root,
2619                                                         disko, diskl, 0,
2620                                                         root->root_key.objectid,
2621                                                         btrfs_ino(inode),
2622                                                         new_key.offset - datao,
2623                                                         0);
2624                                         if (ret) {
2625                                                 btrfs_abort_transaction(trans,
2626                                                                         root,
2627                                                                         ret);
2628                                                 btrfs_end_transaction(trans,
2629                                                                       root);
2630                                                 goto out;
2631
2632                                         }
2633                                 }
2634                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2635                                 u64 skip = 0;
2636                                 u64 trim = 0;
2637                                 if (off > key.offset) {
2638                                         skip = off - key.offset;
2639                                         new_key.offset += skip;
2640                                 }
2641
2642                                 if (key.offset + datal > off+len)
2643                                         trim = key.offset + datal - (off+len);
2644
2645                                 if (comp && (skip || trim)) {
2646                                         ret = -EINVAL;
2647                                         btrfs_end_transaction(trans, root);
2648                                         goto out;
2649                                 }
2650                                 size -= skip + trim;
2651                                 datal -= skip + trim;
2652
2653                                 ret = btrfs_drop_extents(trans, root, inode,
2654                                                          new_key.offset,
2655                                                          new_key.offset + datal,
2656                                                          1);
2657                                 if (ret) {
2658                                         btrfs_abort_transaction(trans, root,
2659                                                                 ret);
2660                                         btrfs_end_transaction(trans, root);
2661                                         goto out;
2662                                 }
2663
2664                                 ret = btrfs_insert_empty_item(trans, root, path,
2665                                                               &new_key, size);
2666                                 if (ret) {
2667                                         btrfs_abort_transaction(trans, root,
2668                                                                 ret);
2669                                         btrfs_end_transaction(trans, root);
2670                                         goto out;
2671                                 }
2672
2673                                 if (skip) {
2674                                         u32 start =
2675                                           btrfs_file_extent_calc_inline_size(0);
2676                                         memmove(buf+start, buf+start+skip,
2677                                                 datal);
2678                                 }
2679
2680                                 leaf = path->nodes[0];
2681                                 slot = path->slots[0];
2682                                 write_extent_buffer(leaf, buf,
2683                                             btrfs_item_ptr_offset(leaf, slot),
2684                                             size);
2685                                 inode_add_bytes(inode, datal);
2686                         }
2687
2688                         btrfs_mark_buffer_dirty(leaf);
2689                         btrfs_release_path(path);
2690
2691                         inode_inc_iversion(inode);
2692                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2693
2694                         /*
2695                          * we round up to the block size at eof when
2696                          * determining which extents to clone above,
2697                          * but shouldn't round up the file size
2698                          */
2699                         endoff = new_key.offset + datal;
2700                         if (endoff > destoff+olen)
2701                                 endoff = destoff+olen;
2702                         if (endoff > inode->i_size)
2703                                 btrfs_i_size_write(inode, endoff);
2704
2705                         ret = btrfs_update_inode(trans, root, inode);
2706                         if (ret) {
2707                                 btrfs_abort_transaction(trans, root, ret);
2708                                 btrfs_end_transaction(trans, root);
2709                                 goto out;
2710                         }
2711                         ret = btrfs_end_transaction(trans, root);
2712                 }
2713 next:
2714                 btrfs_release_path(path);
2715                 key.offset++;
2716         }
2717         ret = 0;
2718 out:
2719         btrfs_release_path(path);
2720         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2721 out_unlock:
2722         mutex_unlock(&src->i_mutex);
2723         mutex_unlock(&inode->i_mutex);
2724         vfree(buf);
2725         btrfs_free_path(path);
2726 out_fput:
2727         fput(src_file);
2728 out_drop_write:
2729         mnt_drop_write_file(file);
2730         return ret;
2731 }
2732
2733 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2734 {
2735         struct btrfs_ioctl_clone_range_args args;
2736
2737         if (copy_from_user(&args, argp, sizeof(args)))
2738                 return -EFAULT;
2739         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2740                                  args.src_length, args.dest_offset);
2741 }
2742
2743 /*
2744  * there are many ways the trans_start and trans_end ioctls can lead
2745  * to deadlocks.  They should only be used by applications that
2746  * basically own the machine, and have a very in depth understanding
2747  * of all the possible deadlocks and enospc problems.
2748  */
2749 static long btrfs_ioctl_trans_start(struct file *file)
2750 {
2751         struct inode *inode = fdentry(file)->d_inode;
2752         struct btrfs_root *root = BTRFS_I(inode)->root;
2753         struct btrfs_trans_handle *trans;
2754         int ret;
2755
2756         ret = -EPERM;
2757         if (!capable(CAP_SYS_ADMIN))
2758                 goto out;
2759
2760         ret = -EINPROGRESS;
2761         if (file->private_data)
2762                 goto out;
2763
2764         ret = -EROFS;
2765         if (btrfs_root_readonly(root))
2766                 goto out;
2767
2768         ret = mnt_want_write_file(file);
2769         if (ret)
2770                 goto out;
2771
2772         atomic_inc(&root->fs_info->open_ioctl_trans);
2773
2774         ret = -ENOMEM;
2775         trans = btrfs_start_ioctl_transaction(root);
2776         if (IS_ERR(trans))
2777                 goto out_drop;
2778
2779         file->private_data = trans;
2780         return 0;
2781
2782 out_drop:
2783         atomic_dec(&root->fs_info->open_ioctl_trans);
2784         mnt_drop_write_file(file);
2785 out:
2786         return ret;
2787 }
2788
2789 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2790 {
2791         struct inode *inode = fdentry(file)->d_inode;
2792         struct btrfs_root *root = BTRFS_I(inode)->root;
2793         struct btrfs_root *new_root;
2794         struct btrfs_dir_item *di;
2795         struct btrfs_trans_handle *trans;
2796         struct btrfs_path *path;
2797         struct btrfs_key location;
2798         struct btrfs_disk_key disk_key;
2799         u64 objectid = 0;
2800         u64 dir_id;
2801
2802         if (!capable(CAP_SYS_ADMIN))
2803                 return -EPERM;
2804
2805         if (copy_from_user(&objectid, argp, sizeof(objectid)))
2806                 return -EFAULT;
2807
2808         if (!objectid)
2809                 objectid = root->root_key.objectid;
2810
2811         location.objectid = objectid;
2812         location.type = BTRFS_ROOT_ITEM_KEY;
2813         location.offset = (u64)-1;
2814
2815         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2816         if (IS_ERR(new_root))
2817                 return PTR_ERR(new_root);
2818
2819         if (btrfs_root_refs(&new_root->root_item) == 0)
2820                 return -ENOENT;
2821
2822         path = btrfs_alloc_path();
2823         if (!path)
2824                 return -ENOMEM;
2825         path->leave_spinning = 1;
2826
2827         trans = btrfs_start_transaction(root, 1);
2828         if (IS_ERR(trans)) {
2829                 btrfs_free_path(path);
2830                 return PTR_ERR(trans);
2831         }
2832
2833         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2834         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2835                                    dir_id, "default", 7, 1);
2836         if (IS_ERR_OR_NULL(di)) {
2837                 btrfs_free_path(path);
2838                 btrfs_end_transaction(trans, root);
2839                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2840                        "this isn't going to work\n");
2841                 return -ENOENT;
2842         }
2843
2844         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2845         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2846         btrfs_mark_buffer_dirty(path->nodes[0]);
2847         btrfs_free_path(path);
2848
2849         btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
2850         btrfs_end_transaction(trans, root);
2851
2852         return 0;
2853 }
2854
2855 static void get_block_group_info(struct list_head *groups_list,
2856                                  struct btrfs_ioctl_space_info *space)
2857 {
2858         struct btrfs_block_group_cache *block_group;
2859
2860         space->total_bytes = 0;
2861         space->used_bytes = 0;
2862         space->flags = 0;
2863         list_for_each_entry(block_group, groups_list, list) {
2864                 space->flags = block_group->flags;
2865                 space->total_bytes += block_group->key.offset;
2866                 space->used_bytes +=
2867                         btrfs_block_group_used(&block_group->item);
2868         }
2869 }
2870
2871 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2872 {
2873         struct btrfs_ioctl_space_args space_args;
2874         struct btrfs_ioctl_space_info space;
2875         struct btrfs_ioctl_space_info *dest;
2876         struct btrfs_ioctl_space_info *dest_orig;
2877         struct btrfs_ioctl_space_info __user *user_dest;
2878         struct btrfs_space_info *info;
2879         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2880                        BTRFS_BLOCK_GROUP_SYSTEM,
2881                        BTRFS_BLOCK_GROUP_METADATA,
2882                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2883         int num_types = 4;
2884         int alloc_size;
2885         int ret = 0;
2886         u64 slot_count = 0;
2887         int i, c;
2888
2889         if (copy_from_user(&space_args,
2890                            (struct btrfs_ioctl_space_args __user *)arg,
2891                            sizeof(space_args)))
2892                 return -EFAULT;
2893
2894         for (i = 0; i < num_types; i++) {
2895                 struct btrfs_space_info *tmp;
2896
2897                 info = NULL;
2898                 rcu_read_lock();
2899                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2900                                         list) {
2901                         if (tmp->flags == types[i]) {
2902                                 info = tmp;
2903                                 break;
2904                         }
2905                 }
2906                 rcu_read_unlock();
2907
2908                 if (!info)
2909                         continue;
2910
2911                 down_read(&info->groups_sem);
2912                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2913                         if (!list_empty(&info->block_groups[c]))
2914                                 slot_count++;
2915                 }
2916                 up_read(&info->groups_sem);
2917         }
2918
2919         /* space_slots == 0 means they are asking for a count */
2920         if (space_args.space_slots == 0) {
2921                 space_args.total_spaces = slot_count;
2922                 goto out;
2923         }
2924
2925         slot_count = min_t(u64, space_args.space_slots, slot_count);
2926
2927         alloc_size = sizeof(*dest) * slot_count;
2928
2929         /* we generally have at most 6 or so space infos, one for each raid
2930          * level.  So, a whole page should be more than enough for everyone
2931          */
2932         if (alloc_size > PAGE_CACHE_SIZE)
2933                 return -ENOMEM;
2934
2935         space_args.total_spaces = 0;
2936         dest = kmalloc(alloc_size, GFP_NOFS);
2937         if (!dest)
2938                 return -ENOMEM;
2939         dest_orig = dest;
2940
2941         /* now we have a buffer to copy into */
2942         for (i = 0; i < num_types; i++) {
2943                 struct btrfs_space_info *tmp;
2944
2945                 if (!slot_count)
2946                         break;
2947
2948                 info = NULL;
2949                 rcu_read_lock();
2950                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2951                                         list) {
2952                         if (tmp->flags == types[i]) {
2953                                 info = tmp;
2954                                 break;
2955                         }
2956                 }
2957                 rcu_read_unlock();
2958
2959                 if (!info)
2960                         continue;
2961                 down_read(&info->groups_sem);
2962                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2963                         if (!list_empty(&info->block_groups[c])) {
2964                                 get_block_group_info(&info->block_groups[c],
2965                                                      &space);
2966                                 memcpy(dest, &space, sizeof(space));
2967                                 dest++;
2968                                 space_args.total_spaces++;
2969                                 slot_count--;
2970                         }
2971                         if (!slot_count)
2972                                 break;
2973                 }
2974                 up_read(&info->groups_sem);
2975         }
2976
2977         user_dest = (struct btrfs_ioctl_space_info __user *)
2978                 (arg + sizeof(struct btrfs_ioctl_space_args));
2979
2980         if (copy_to_user(user_dest, dest_orig, alloc_size))
2981                 ret = -EFAULT;
2982
2983         kfree(dest_orig);
2984 out:
2985         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2986                 ret = -EFAULT;
2987
2988         return ret;
2989 }
2990
2991 /*
2992  * there are many ways the trans_start and trans_end ioctls can lead
2993  * to deadlocks.  They should only be used by applications that
2994  * basically own the machine, and have a very in depth understanding
2995  * of all the possible deadlocks and enospc problems.
2996  */
2997 long btrfs_ioctl_trans_end(struct file *file)
2998 {
2999         struct inode *inode = fdentry(file)->d_inode;
3000         struct btrfs_root *root = BTRFS_I(inode)->root;
3001         struct btrfs_trans_handle *trans;
3002
3003         trans = file->private_data;
3004         if (!trans)
3005                 return -EINVAL;
3006         file->private_data = NULL;
3007
3008         btrfs_end_transaction(trans, root);
3009
3010         atomic_dec(&root->fs_info->open_ioctl_trans);
3011
3012         mnt_drop_write_file(file);
3013         return 0;
3014 }
3015
3016 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
3017 {
3018         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
3019         struct btrfs_trans_handle *trans;
3020         u64 transid;
3021         int ret;
3022
3023         trans = btrfs_start_transaction(root, 0);
3024         if (IS_ERR(trans))
3025                 return PTR_ERR(trans);
3026         transid = trans->transid;
3027         ret = btrfs_commit_transaction_async(trans, root, 0);
3028         if (ret) {
3029                 btrfs_end_transaction(trans, root);
3030                 return ret;
3031         }
3032
3033         if (argp)
3034                 if (copy_to_user(argp, &transid, sizeof(transid)))
3035                         return -EFAULT;
3036         return 0;
3037 }
3038
3039 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
3040 {
3041         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
3042         u64 transid;
3043
3044         if (argp) {
3045                 if (copy_from_user(&transid, argp, sizeof(transid)))
3046                         return -EFAULT;
3047         } else {
3048                 transid = 0;  /* current trans */
3049         }
3050         return btrfs_wait_for_commit(root, transid);
3051 }
3052
3053 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
3054 {
3055         int ret;
3056         struct btrfs_ioctl_scrub_args *sa;
3057
3058         if (!capable(CAP_SYS_ADMIN))
3059                 return -EPERM;
3060
3061         sa = memdup_user(arg, sizeof(*sa));
3062         if (IS_ERR(sa))
3063                 return PTR_ERR(sa);
3064
3065         ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
3066                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
3067
3068         if (copy_to_user(arg, sa, sizeof(*sa)))
3069                 ret = -EFAULT;
3070
3071         kfree(sa);
3072         return ret;
3073 }
3074
3075 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3076 {
3077         if (!capable(CAP_SYS_ADMIN))
3078                 return -EPERM;
3079
3080         return btrfs_scrub_cancel(root);
3081 }
3082
3083 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3084                                        void __user *arg)
3085 {
3086         struct btrfs_ioctl_scrub_args *sa;
3087         int ret;
3088
3089         if (!capable(CAP_SYS_ADMIN))
3090                 return -EPERM;
3091
3092         sa = memdup_user(arg, sizeof(*sa));
3093         if (IS_ERR(sa))
3094                 return PTR_ERR(sa);
3095
3096         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3097
3098         if (copy_to_user(arg, sa, sizeof(*sa)))
3099                 ret = -EFAULT;
3100
3101         kfree(sa);
3102         return ret;
3103 }
3104
3105 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3106                                       void __user *arg)
3107 {
3108         struct btrfs_ioctl_get_dev_stats *sa;
3109         int ret;
3110
3111         sa = memdup_user(arg, sizeof(*sa));
3112         if (IS_ERR(sa))
3113                 return PTR_ERR(sa);
3114
3115         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3116                 kfree(sa);
3117                 return -EPERM;
3118         }
3119
3120         ret = btrfs_get_dev_stats(root, sa);
3121
3122         if (copy_to_user(arg, sa, sizeof(*sa)))
3123                 ret = -EFAULT;
3124
3125         kfree(sa);
3126         return ret;
3127 }
3128
3129 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3130 {
3131         int ret = 0;
3132         int i;
3133         u64 rel_ptr;
3134         int size;
3135         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3136         struct inode_fs_paths *ipath = NULL;
3137         struct btrfs_path *path;
3138
3139         if (!capable(CAP_SYS_ADMIN))
3140                 return -EPERM;
3141
3142         path = btrfs_alloc_path();
3143         if (!path) {
3144                 ret = -ENOMEM;
3145                 goto out;
3146         }
3147
3148         ipa = memdup_user(arg, sizeof(*ipa));
3149         if (IS_ERR(ipa)) {
3150                 ret = PTR_ERR(ipa);
3151                 ipa = NULL;
3152                 goto out;
3153         }
3154
3155         size = min_t(u32, ipa->size, 4096);
3156         ipath = init_ipath(size, root, path);
3157         if (IS_ERR(ipath)) {
3158                 ret = PTR_ERR(ipath);
3159                 ipath = NULL;
3160                 goto out;
3161         }
3162
3163         ret = paths_from_inode(ipa->inum, ipath);
3164         if (ret < 0)
3165                 goto out;
3166
3167         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3168                 rel_ptr = ipath->fspath->val[i] -
3169                           (u64)(unsigned long)ipath->fspath->val;
3170                 ipath->fspath->val[i] = rel_ptr;
3171         }
3172
3173         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
3174                            (void *)(unsigned long)ipath->fspath, size);
3175         if (ret) {
3176                 ret = -EFAULT;
3177                 goto out;
3178         }
3179
3180 out:
3181         btrfs_free_path(path);
3182         free_ipath(ipath);
3183         kfree(ipa);
3184
3185         return ret;
3186 }
3187
3188 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3189 {
3190         struct btrfs_data_container *inodes = ctx;
3191         const size_t c = 3 * sizeof(u64);
3192
3193         if (inodes->bytes_left >= c) {
3194                 inodes->bytes_left -= c;
3195                 inodes->val[inodes->elem_cnt] = inum;
3196                 inodes->val[inodes->elem_cnt + 1] = offset;
3197                 inodes->val[inodes->elem_cnt + 2] = root;
3198                 inodes->elem_cnt += 3;
3199         } else {
3200                 inodes->bytes_missing += c - inodes->bytes_left;
3201                 inodes->bytes_left = 0;
3202                 inodes->elem_missed += 3;
3203         }
3204
3205         return 0;
3206 }
3207
3208 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3209                                         void __user *arg)
3210 {
3211         int ret = 0;
3212         int size;
3213         struct btrfs_ioctl_logical_ino_args *loi;
3214         struct btrfs_data_container *inodes = NULL;
3215         struct btrfs_path *path = NULL;
3216
3217         if (!capable(CAP_SYS_ADMIN))
3218                 return -EPERM;
3219
3220         loi = memdup_user(arg, sizeof(*loi));
3221         if (IS_ERR(loi)) {
3222                 ret = PTR_ERR(loi);
3223                 loi = NULL;
3224                 goto out;
3225         }
3226
3227         path = btrfs_alloc_path();
3228         if (!path) {
3229                 ret = -ENOMEM;
3230                 goto out;
3231         }
3232
3233         size = min_t(u32, loi->size, 64 * 1024);
3234         inodes = init_data_container(size);
3235         if (IS_ERR(inodes)) {
3236                 ret = PTR_ERR(inodes);
3237                 inodes = NULL;
3238                 goto out;
3239         }
3240
3241         ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
3242                                           build_ino_list, inodes);
3243         if (ret == -EINVAL)
3244                 ret = -ENOENT;
3245         if (ret < 0)
3246                 goto out;
3247
3248         ret = copy_to_user((void *)(unsigned long)loi->inodes,
3249                            (void *)(unsigned long)inodes, size);
3250         if (ret)
3251                 ret = -EFAULT;
3252
3253 out:
3254         btrfs_free_path(path);
3255         vfree(inodes);
3256         kfree(loi);
3257
3258         return ret;
3259 }
3260
3261 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3262                                struct btrfs_ioctl_balance_args *bargs)
3263 {
3264         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3265
3266         bargs->flags = bctl->flags;
3267
3268         if (atomic_read(&fs_info->balance_running))
3269                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3270         if (atomic_read(&fs_info->balance_pause_req))
3271                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3272         if (atomic_read(&fs_info->balance_cancel_req))
3273                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3274
3275         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3276         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3277         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3278
3279         if (lock) {
3280                 spin_lock(&fs_info->balance_lock);
3281                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3282                 spin_unlock(&fs_info->balance_lock);
3283         } else {
3284                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3285         }
3286 }
3287
3288 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3289 {
3290         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3291         struct btrfs_fs_info *fs_info = root->fs_info;
3292         struct btrfs_ioctl_balance_args *bargs;
3293         struct btrfs_balance_control *bctl;
3294         int ret;
3295
3296         if (!capable(CAP_SYS_ADMIN))
3297                 return -EPERM;
3298
3299         ret = mnt_want_write_file(file);
3300         if (ret)
3301                 return ret;
3302
3303         mutex_lock(&fs_info->volume_mutex);
3304         mutex_lock(&fs_info->balance_mutex);
3305
3306         if (arg) {
3307                 bargs = memdup_user(arg, sizeof(*bargs));
3308                 if (IS_ERR(bargs)) {
3309                         ret = PTR_ERR(bargs);
3310                         goto out;
3311                 }
3312
3313                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
3314                         if (!fs_info->balance_ctl) {
3315                                 ret = -ENOTCONN;
3316                                 goto out_bargs;
3317                         }
3318
3319                         bctl = fs_info->balance_ctl;
3320                         spin_lock(&fs_info->balance_lock);
3321                         bctl->flags |= BTRFS_BALANCE_RESUME;
3322                         spin_unlock(&fs_info->balance_lock);
3323
3324                         goto do_balance;
3325                 }
3326         } else {
3327                 bargs = NULL;
3328         }
3329
3330         if (fs_info->balance_ctl) {
3331                 ret = -EINPROGRESS;
3332                 goto out_bargs;
3333         }
3334
3335         bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3336         if (!bctl) {
3337                 ret = -ENOMEM;
3338                 goto out_bargs;
3339         }
3340
3341         bctl->fs_info = fs_info;
3342         if (arg) {
3343                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3344                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3345                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3346
3347                 bctl->flags = bargs->flags;
3348         } else {
3349                 /* balance everything - no filters */
3350                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3351         }
3352
3353 do_balance:
3354         ret = btrfs_balance(bctl, bargs);
3355         /*
3356          * bctl is freed in __cancel_balance or in free_fs_info if
3357          * restriper was paused all the way until unmount
3358          */
3359         if (arg) {
3360                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3361                         ret = -EFAULT;
3362         }
3363
3364 out_bargs:
3365         kfree(bargs);
3366 out:
3367         mutex_unlock(&fs_info->balance_mutex);
3368         mutex_unlock(&fs_info->volume_mutex);
3369         mnt_drop_write_file(file);
3370         return ret;
3371 }
3372
3373 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
3374 {
3375         if (!capable(CAP_SYS_ADMIN))
3376                 return -EPERM;
3377
3378         switch (cmd) {
3379         case BTRFS_BALANCE_CTL_PAUSE:
3380                 return btrfs_pause_balance(root->fs_info);
3381         case BTRFS_BALANCE_CTL_CANCEL:
3382                 return btrfs_cancel_balance(root->fs_info);
3383         }
3384
3385         return -EINVAL;
3386 }
3387
3388 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
3389                                          void __user *arg)
3390 {
3391         struct btrfs_fs_info *fs_info = root->fs_info;
3392         struct btrfs_ioctl_balance_args *bargs;
3393         int ret = 0;
3394
3395         if (!capable(CAP_SYS_ADMIN))
3396                 return -EPERM;
3397
3398         mutex_lock(&fs_info->balance_mutex);
3399         if (!fs_info->balance_ctl) {
3400                 ret = -ENOTCONN;
3401                 goto out;
3402         }
3403
3404         bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
3405         if (!bargs) {
3406                 ret = -ENOMEM;
3407                 goto out;
3408         }
3409
3410         update_ioctl_balance_args(fs_info, 1, bargs);
3411
3412         if (copy_to_user(arg, bargs, sizeof(*bargs)))
3413                 ret = -EFAULT;
3414
3415         kfree(bargs);
3416 out:
3417         mutex_unlock(&fs_info->balance_mutex);
3418         return ret;
3419 }
3420
3421 static long btrfs_ioctl_quota_ctl(struct btrfs_root *root, void __user *arg)
3422 {
3423         struct btrfs_ioctl_quota_ctl_args *sa;
3424         struct btrfs_trans_handle *trans = NULL;
3425         int ret;
3426         int err;
3427
3428         if (!capable(CAP_SYS_ADMIN))
3429                 return -EPERM;
3430
3431         if (root->fs_info->sb->s_flags & MS_RDONLY)
3432                 return -EROFS;
3433
3434         sa = memdup_user(arg, sizeof(*sa));
3435         if (IS_ERR(sa))
3436                 return PTR_ERR(sa);
3437
3438         if (sa->cmd != BTRFS_QUOTA_CTL_RESCAN) {
3439                 trans = btrfs_start_transaction(root, 2);
3440                 if (IS_ERR(trans)) {
3441                         ret = PTR_ERR(trans);
3442                         goto out;
3443                 }
3444         }
3445
3446         switch (sa->cmd) {
3447         case BTRFS_QUOTA_CTL_ENABLE:
3448                 ret = btrfs_quota_enable(trans, root->fs_info);
3449                 break;
3450         case BTRFS_QUOTA_CTL_DISABLE:
3451                 ret = btrfs_quota_disable(trans, root->fs_info);
3452                 break;
3453         case BTRFS_QUOTA_CTL_RESCAN:
3454                 ret = btrfs_quota_rescan(root->fs_info);
3455                 break;
3456         default:
3457                 ret = -EINVAL;
3458                 break;
3459         }
3460
3461         if (copy_to_user(arg, sa, sizeof(*sa)))
3462                 ret = -EFAULT;
3463
3464         if (trans) {
3465                 err = btrfs_commit_transaction(trans, root);
3466                 if (err && !ret)
3467                         ret = err;
3468         }
3469
3470 out:
3471         kfree(sa);
3472         return ret;
3473 }
3474
3475 static long btrfs_ioctl_qgroup_assign(struct btrfs_root *root, void __user *arg)
3476 {
3477         struct btrfs_ioctl_qgroup_assign_args *sa;
3478         struct btrfs_trans_handle *trans;
3479         int ret;
3480         int err;
3481
3482         if (!capable(CAP_SYS_ADMIN))
3483                 return -EPERM;
3484
3485         if (root->fs_info->sb->s_flags & MS_RDONLY)
3486                 return -EROFS;
3487
3488         sa = memdup_user(arg, sizeof(*sa));
3489         if (IS_ERR(sa))
3490                 return PTR_ERR(sa);
3491
3492         trans = btrfs_join_transaction(root);
3493         if (IS_ERR(trans)) {
3494                 ret = PTR_ERR(trans);
3495                 goto out;
3496         }
3497
3498         /* FIXME: check if the IDs really exist */
3499         if (sa->assign) {
3500                 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
3501                                                 sa->src, sa->dst);
3502         } else {
3503                 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
3504                                                 sa->src, sa->dst);
3505         }
3506
3507         err = btrfs_end_transaction(trans, root);
3508         if (err && !ret)
3509                 ret = err;
3510
3511 out:
3512         kfree(sa);
3513         return ret;
3514 }
3515
3516 static long btrfs_ioctl_qgroup_create(struct btrfs_root *root, void __user *arg)
3517 {
3518         struct btrfs_ioctl_qgroup_create_args *sa;
3519         struct btrfs_trans_handle *trans;
3520         int ret;
3521         int err;
3522
3523         if (!capable(CAP_SYS_ADMIN))
3524                 return -EPERM;
3525
3526         if (root->fs_info->sb->s_flags & MS_RDONLY)
3527                 return -EROFS;
3528
3529         sa = memdup_user(arg, sizeof(*sa));
3530         if (IS_ERR(sa))
3531                 return PTR_ERR(sa);
3532
3533         trans = btrfs_join_transaction(root);
3534         if (IS_ERR(trans)) {
3535                 ret = PTR_ERR(trans);
3536                 goto out;
3537         }
3538
3539         /* FIXME: check if the IDs really exist */
3540         if (sa->create) {
3541                 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
3542                                           NULL);
3543         } else {
3544                 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
3545         }
3546
3547         err = btrfs_end_transaction(trans, root);
3548         if (err && !ret)
3549                 ret = err;
3550
3551 out:
3552         kfree(sa);
3553         return ret;
3554 }
3555
3556 static long btrfs_ioctl_qgroup_limit(struct btrfs_root *root, void __user *arg)
3557 {
3558         struct btrfs_ioctl_qgroup_limit_args *sa;
3559         struct btrfs_trans_handle *trans;
3560         int ret;
3561         int err;
3562         u64 qgroupid;
3563
3564         if (!capable(CAP_SYS_ADMIN))
3565                 return -EPERM;
3566
3567         if (root->fs_info->sb->s_flags & MS_RDONLY)
3568                 return -EROFS;
3569
3570         sa = memdup_user(arg, sizeof(*sa));
3571         if (IS_ERR(sa))
3572                 return PTR_ERR(sa);
3573
3574         trans = btrfs_join_transaction(root);
3575         if (IS_ERR(trans)) {
3576                 ret = PTR_ERR(trans);
3577                 goto out;
3578         }
3579
3580         qgroupid = sa->qgroupid;
3581         if (!qgroupid) {
3582                 /* take the current subvol as qgroup */
3583                 qgroupid = root->root_key.objectid;
3584         }
3585
3586         /* FIXME: check if the IDs really exist */
3587         ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
3588
3589         err = btrfs_end_transaction(trans, root);
3590         if (err && !ret)
3591                 ret = err;
3592
3593 out:
3594         kfree(sa);
3595         return ret;
3596 }
3597
3598 static long btrfs_ioctl_set_received_subvol(struct file *file,
3599                                             void __user *arg)
3600 {
3601         struct btrfs_ioctl_received_subvol_args *sa = NULL;
3602         struct inode *inode = fdentry(file)->d_inode;
3603         struct btrfs_root *root = BTRFS_I(inode)->root;
3604         struct btrfs_root_item *root_item = &root->root_item;
3605         struct btrfs_trans_handle *trans;
3606         struct timespec ct = CURRENT_TIME;
3607         int ret = 0;
3608
3609         ret = mnt_want_write_file(file);
3610         if (ret < 0)
3611                 return ret;
3612
3613         down_write(&root->fs_info->subvol_sem);
3614
3615         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
3616                 ret = -EINVAL;
3617                 goto out;
3618         }
3619
3620         if (btrfs_root_readonly(root)) {
3621                 ret = -EROFS;
3622                 goto out;
3623         }
3624
3625         if (!inode_owner_or_capable(inode)) {
3626                 ret = -EACCES;
3627                 goto out;
3628         }
3629
3630         sa = memdup_user(arg, sizeof(*sa));
3631         if (IS_ERR(sa)) {
3632                 ret = PTR_ERR(sa);
3633                 sa = NULL;
3634                 goto out;
3635         }
3636
3637         trans = btrfs_start_transaction(root, 1);
3638         if (IS_ERR(trans)) {
3639                 ret = PTR_ERR(trans);
3640                 trans = NULL;
3641                 goto out;
3642         }
3643
3644         sa->rtransid = trans->transid;
3645         sa->rtime.sec = ct.tv_sec;
3646         sa->rtime.nsec = ct.tv_nsec;
3647
3648         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
3649         btrfs_set_root_stransid(root_item, sa->stransid);
3650         btrfs_set_root_rtransid(root_item, sa->rtransid);
3651         root_item->stime.sec = cpu_to_le64(sa->stime.sec);
3652         root_item->stime.nsec = cpu_to_le32(sa->stime.nsec);
3653         root_item->rtime.sec = cpu_to_le64(sa->rtime.sec);
3654         root_item->rtime.nsec = cpu_to_le32(sa->rtime.nsec);
3655
3656         ret = btrfs_update_root(trans, root->fs_info->tree_root,
3657                                 &root->root_key, &root->root_item);
3658         if (ret < 0) {
3659                 btrfs_end_transaction(trans, root);
3660                 trans = NULL;
3661                 goto out;
3662         } else {
3663                 ret = btrfs_commit_transaction(trans, root);
3664                 if (ret < 0)
3665                         goto out;
3666         }
3667
3668         ret = copy_to_user(arg, sa, sizeof(*sa));
3669         if (ret)
3670                 ret = -EFAULT;
3671
3672 out:
3673         kfree(sa);
3674         up_write(&root->fs_info->subvol_sem);
3675         mnt_drop_write_file(file);
3676         return ret;
3677 }
3678
3679 long btrfs_ioctl(struct file *file, unsigned int
3680                 cmd, unsigned long arg)
3681 {
3682         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3683         void __user *argp = (void __user *)arg;
3684
3685         switch (cmd) {
3686         case FS_IOC_GETFLAGS:
3687                 return btrfs_ioctl_getflags(file, argp);
3688         case FS_IOC_SETFLAGS:
3689                 return btrfs_ioctl_setflags(file, argp);
3690         case FS_IOC_GETVERSION:
3691                 return btrfs_ioctl_getversion(file, argp);
3692         case FITRIM:
3693                 return btrfs_ioctl_fitrim(file, argp);
3694         case BTRFS_IOC_SNAP_CREATE:
3695                 return btrfs_ioctl_snap_create(file, argp, 0);
3696         case BTRFS_IOC_SNAP_CREATE_V2:
3697                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
3698         case BTRFS_IOC_SUBVOL_CREATE:
3699                 return btrfs_ioctl_snap_create(file, argp, 1);
3700         case BTRFS_IOC_SUBVOL_CREATE_V2:
3701                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
3702         case BTRFS_IOC_SNAP_DESTROY:
3703                 return btrfs_ioctl_snap_destroy(file, argp);
3704         case BTRFS_IOC_SUBVOL_GETFLAGS:
3705                 return btrfs_ioctl_subvol_getflags(file, argp);
3706         case BTRFS_IOC_SUBVOL_SETFLAGS:
3707                 return btrfs_ioctl_subvol_setflags(file, argp);
3708         case BTRFS_IOC_DEFAULT_SUBVOL:
3709                 return btrfs_ioctl_default_subvol(file, argp);
3710         case BTRFS_IOC_DEFRAG:
3711                 return btrfs_ioctl_defrag(file, NULL);
3712         case BTRFS_IOC_DEFRAG_RANGE:
3713                 return btrfs_ioctl_defrag(file, argp);
3714         case BTRFS_IOC_RESIZE:
3715                 return btrfs_ioctl_resize(root, argp);
3716         case BTRFS_IOC_ADD_DEV:
3717                 return btrfs_ioctl_add_dev(root, argp);
3718         case BTRFS_IOC_RM_DEV:
3719                 return btrfs_ioctl_rm_dev(root, argp);
3720         case BTRFS_IOC_FS_INFO:
3721                 return btrfs_ioctl_fs_info(root, argp);
3722         case BTRFS_IOC_DEV_INFO:
3723                 return btrfs_ioctl_dev_info(root, argp);
3724         case BTRFS_IOC_BALANCE:
3725                 return btrfs_ioctl_balance(file, NULL);
3726         case BTRFS_IOC_CLONE:
3727                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3728         case BTRFS_IOC_CLONE_RANGE:
3729                 return btrfs_ioctl_clone_range(file, argp);
3730         case BTRFS_IOC_TRANS_START:
3731                 return btrfs_ioctl_trans_start(file);
3732         case BTRFS_IOC_TRANS_END:
3733                 return btrfs_ioctl_trans_end(file);
3734         case BTRFS_IOC_TREE_SEARCH:
3735                 return btrfs_ioctl_tree_search(file, argp);
3736         case BTRFS_IOC_INO_LOOKUP:
3737                 return btrfs_ioctl_ino_lookup(file, argp);
3738         case BTRFS_IOC_INO_PATHS:
3739                 return btrfs_ioctl_ino_to_path(root, argp);
3740         case BTRFS_IOC_LOGICAL_INO:
3741                 return btrfs_ioctl_logical_to_ino(root, argp);
3742         case BTRFS_IOC_SPACE_INFO:
3743                 return btrfs_ioctl_space_info(root, argp);
3744         case BTRFS_IOC_SYNC:
3745                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
3746                 return 0;
3747         case BTRFS_IOC_START_SYNC:
3748                 return btrfs_ioctl_start_sync(file, argp);
3749         case BTRFS_IOC_WAIT_SYNC:
3750                 return btrfs_ioctl_wait_sync(file, argp);
3751         case BTRFS_IOC_SCRUB:
3752                 return btrfs_ioctl_scrub(root, argp);
3753         case BTRFS_IOC_SCRUB_CANCEL:
3754                 return btrfs_ioctl_scrub_cancel(root, argp);
3755         case BTRFS_IOC_SCRUB_PROGRESS:
3756                 return btrfs_ioctl_scrub_progress(root, argp);
3757         case BTRFS_IOC_BALANCE_V2:
3758                 return btrfs_ioctl_balance(file, argp);
3759         case BTRFS_IOC_BALANCE_CTL:
3760                 return btrfs_ioctl_balance_ctl(root, arg);
3761         case BTRFS_IOC_BALANCE_PROGRESS:
3762                 return btrfs_ioctl_balance_progress(root, argp);
3763         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
3764                 return btrfs_ioctl_set_received_subvol(file, argp);
3765         case BTRFS_IOC_SEND:
3766                 return btrfs_ioctl_send(file, argp);
3767         case BTRFS_IOC_GET_DEV_STATS:
3768                 return btrfs_ioctl_get_dev_stats(root, argp);
3769         case BTRFS_IOC_QUOTA_CTL:
3770                 return btrfs_ioctl_quota_ctl(root, argp);
3771         case BTRFS_IOC_QGROUP_ASSIGN:
3772                 return btrfs_ioctl_qgroup_assign(root, argp);
3773         case BTRFS_IOC_QGROUP_CREATE:
3774                 return btrfs_ioctl_qgroup_create(root, argp);
3775         case BTRFS_IOC_QGROUP_LIMIT:
3776                 return btrfs_ioctl_qgroup_limit(root, argp);
3777         }
3778
3779         return -ENOTTY;
3780 }