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