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