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   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}
v4.6
   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 <linux/btrfs.h>
  46#include <linux/uaccess.h>
  47#include "ctree.h"
  48#include "disk-io.h"
  49#include "transaction.h"
  50#include "btrfs_inode.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#include "dev-replace.h"
  59#include "props.h"
  60#include "sysfs.h"
  61#include "qgroup.h"
  62#include "tree-log.h"
  63#include "compression.h"
  64
  65#ifdef CONFIG_64BIT
  66/* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  67 * structures are incorrect, as the timespec structure from userspace
  68 * is 4 bytes too small. We define these alternatives here to teach
  69 * the kernel about the 32-bit struct packing.
  70 */
  71struct btrfs_ioctl_timespec_32 {
  72	__u64 sec;
  73	__u32 nsec;
  74} __attribute__ ((__packed__));
  75
  76struct btrfs_ioctl_received_subvol_args_32 {
  77	char	uuid[BTRFS_UUID_SIZE];	/* in */
  78	__u64	stransid;		/* in */
  79	__u64	rtransid;		/* out */
  80	struct btrfs_ioctl_timespec_32 stime; /* in */
  81	struct btrfs_ioctl_timespec_32 rtime; /* out */
  82	__u64	flags;			/* in */
  83	__u64	reserved[16];		/* in */
  84} __attribute__ ((__packed__));
  85
  86#define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  87				struct btrfs_ioctl_received_subvol_args_32)
  88#endif
  89
  90
  91static int btrfs_clone(struct inode *src, struct inode *inode,
  92		       u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  93		       int no_time_update);
  94
  95/* Mask out flags that are inappropriate for the given type of inode. */
  96static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  97{
  98	if (S_ISDIR(mode))
  99		return flags;
 100	else if (S_ISREG(mode))
 101		return flags & ~FS_DIRSYNC_FL;
 102	else
 103		return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 104}
 105
 106/*
 107 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
 108 */
 109static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
 110{
 111	unsigned int iflags = 0;
 112
 113	if (flags & BTRFS_INODE_SYNC)
 114		iflags |= FS_SYNC_FL;
 115	if (flags & BTRFS_INODE_IMMUTABLE)
 116		iflags |= FS_IMMUTABLE_FL;
 117	if (flags & BTRFS_INODE_APPEND)
 118		iflags |= FS_APPEND_FL;
 119	if (flags & BTRFS_INODE_NODUMP)
 120		iflags |= FS_NODUMP_FL;
 121	if (flags & BTRFS_INODE_NOATIME)
 122		iflags |= FS_NOATIME_FL;
 123	if (flags & BTRFS_INODE_DIRSYNC)
 124		iflags |= FS_DIRSYNC_FL;
 125	if (flags & BTRFS_INODE_NODATACOW)
 126		iflags |= FS_NOCOW_FL;
 127
 128	if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
 129		iflags |= FS_COMPR_FL;
 130	else if (flags & BTRFS_INODE_NOCOMPRESS)
 131		iflags |= FS_NOCOMP_FL;
 132
 133	return iflags;
 134}
 135
 136/*
 137 * Update inode->i_flags based on the btrfs internal flags.
 138 */
 139void btrfs_update_iflags(struct inode *inode)
 140{
 141	struct btrfs_inode *ip = BTRFS_I(inode);
 142	unsigned int new_fl = 0;
 
 143
 144	if (ip->flags & BTRFS_INODE_SYNC)
 145		new_fl |= S_SYNC;
 146	if (ip->flags & BTRFS_INODE_IMMUTABLE)
 147		new_fl |= S_IMMUTABLE;
 148	if (ip->flags & BTRFS_INODE_APPEND)
 149		new_fl |= S_APPEND;
 150	if (ip->flags & BTRFS_INODE_NOATIME)
 151		new_fl |= S_NOATIME;
 152	if (ip->flags & BTRFS_INODE_DIRSYNC)
 153		new_fl |= S_DIRSYNC;
 154
 155	set_mask_bits(&inode->i_flags,
 156		      S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 157		      new_fl);
 158}
 159
 160/*
 161 * Inherit flags from the parent inode.
 162 *
 163 * Currently only the compression flags and the cow flags are inherited.
 164 */
 165void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 166{
 167	unsigned int flags;
 168
 169	if (!dir)
 170		return;
 171
 172	flags = BTRFS_I(dir)->flags;
 173
 174	if (flags & BTRFS_INODE_NOCOMPRESS) {
 175		BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 176		BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 177	} else if (flags & BTRFS_INODE_COMPRESS) {
 178		BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 179		BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 180	}
 181
 182	if (flags & BTRFS_INODE_NODATACOW) {
 183		BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 184		if (S_ISREG(inode->i_mode))
 185			BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
 186	}
 187
 
 188	btrfs_update_iflags(inode);
 189}
 190
 191static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 192{
 193	struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 194	unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 195
 196	if (copy_to_user(arg, &flags, sizeof(flags)))
 197		return -EFAULT;
 198	return 0;
 199}
 200
 201static int check_flags(unsigned int flags)
 202{
 203	if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 204		      FS_NOATIME_FL | FS_NODUMP_FL | \
 205		      FS_SYNC_FL | FS_DIRSYNC_FL | \
 206		      FS_NOCOMP_FL | FS_COMPR_FL |
 207		      FS_NOCOW_FL))
 208		return -EOPNOTSUPP;
 209
 210	if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 211		return -EINVAL;
 212
 213	return 0;
 214}
 215
 216static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 217{
 218	struct inode *inode = file_inode(file);
 219	struct btrfs_inode *ip = BTRFS_I(inode);
 220	struct btrfs_root *root = ip->root;
 221	struct btrfs_trans_handle *trans;
 222	unsigned int flags, oldflags;
 223	int ret;
 224	u64 ip_oldflags;
 225	unsigned int i_oldflags;
 226	umode_t mode;
 227
 228	if (!inode_owner_or_capable(inode))
 229		return -EPERM;
 230
 231	if (btrfs_root_readonly(root))
 232		return -EROFS;
 233
 234	if (copy_from_user(&flags, arg, sizeof(flags)))
 235		return -EFAULT;
 236
 237	ret = check_flags(flags);
 238	if (ret)
 239		return ret;
 240
 241	ret = mnt_want_write_file(file);
 242	if (ret)
 243		return ret;
 244
 245	inode_lock(inode);
 246
 247	ip_oldflags = ip->flags;
 248	i_oldflags = inode->i_flags;
 249	mode = inode->i_mode;
 250
 251	flags = btrfs_mask_flags(inode->i_mode, flags);
 252	oldflags = btrfs_flags_to_ioctl(ip->flags);
 253	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 254		if (!capable(CAP_LINUX_IMMUTABLE)) {
 255			ret = -EPERM;
 256			goto out_unlock;
 257		}
 258	}
 259
 
 
 
 
 260	if (flags & FS_SYNC_FL)
 261		ip->flags |= BTRFS_INODE_SYNC;
 262	else
 263		ip->flags &= ~BTRFS_INODE_SYNC;
 264	if (flags & FS_IMMUTABLE_FL)
 265		ip->flags |= BTRFS_INODE_IMMUTABLE;
 266	else
 267		ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 268	if (flags & FS_APPEND_FL)
 269		ip->flags |= BTRFS_INODE_APPEND;
 270	else
 271		ip->flags &= ~BTRFS_INODE_APPEND;
 272	if (flags & FS_NODUMP_FL)
 273		ip->flags |= BTRFS_INODE_NODUMP;
 274	else
 275		ip->flags &= ~BTRFS_INODE_NODUMP;
 276	if (flags & FS_NOATIME_FL)
 277		ip->flags |= BTRFS_INODE_NOATIME;
 278	else
 279		ip->flags &= ~BTRFS_INODE_NOATIME;
 280	if (flags & FS_DIRSYNC_FL)
 281		ip->flags |= BTRFS_INODE_DIRSYNC;
 282	else
 283		ip->flags &= ~BTRFS_INODE_DIRSYNC;
 284	if (flags & FS_NOCOW_FL) {
 285		if (S_ISREG(mode)) {
 286			/*
 287			 * It's safe to turn csums off here, no extents exist.
 288			 * Otherwise we want the flag to reflect the real COW
 289			 * status of the file and will not set it.
 290			 */
 291			if (inode->i_size == 0)
 292				ip->flags |= BTRFS_INODE_NODATACOW
 293					   | BTRFS_INODE_NODATASUM;
 294		} else {
 295			ip->flags |= BTRFS_INODE_NODATACOW;
 296		}
 297	} else {
 298		/*
 299		 * Revert back under same assuptions as above
 300		 */
 301		if (S_ISREG(mode)) {
 302			if (inode->i_size == 0)
 303				ip->flags &= ~(BTRFS_INODE_NODATACOW
 304				             | BTRFS_INODE_NODATASUM);
 305		} else {
 306			ip->flags &= ~BTRFS_INODE_NODATACOW;
 307		}
 308	}
 309
 310	/*
 311	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 312	 * flag may be changed automatically if compression code won't make
 313	 * things smaller.
 314	 */
 315	if (flags & FS_NOCOMP_FL) {
 316		ip->flags &= ~BTRFS_INODE_COMPRESS;
 317		ip->flags |= BTRFS_INODE_NOCOMPRESS;
 318
 319		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 320		if (ret && ret != -ENODATA)
 321			goto out_drop;
 322	} else if (flags & FS_COMPR_FL) {
 323		const char *comp;
 324
 325		ip->flags |= BTRFS_INODE_COMPRESS;
 326		ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 327
 328		if (root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
 329			comp = "lzo";
 330		else
 331			comp = "zlib";
 332		ret = btrfs_set_prop(inode, "btrfs.compression",
 333				     comp, strlen(comp), 0);
 334		if (ret)
 335			goto out_drop;
 336
 337	} else {
 338		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 339		if (ret && ret != -ENODATA)
 340			goto out_drop;
 341		ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 342	}
 343
 344	trans = btrfs_start_transaction(root, 1);
 345	if (IS_ERR(trans)) {
 346		ret = PTR_ERR(trans);
 347		goto out_drop;
 348	}
 349
 350	btrfs_update_iflags(inode);
 351	inode_inc_iversion(inode);
 352	inode->i_ctime = current_fs_time(inode->i_sb);
 353	ret = btrfs_update_inode(trans, root, inode);
 
 354
 
 
 355	btrfs_end_transaction(trans, root);
 356 out_drop:
 357	if (ret) {
 358		ip->flags = ip_oldflags;
 359		inode->i_flags = i_oldflags;
 360	}
 361
 
 
 
 362 out_unlock:
 363	inode_unlock(inode);
 364	mnt_drop_write_file(file);
 365	return ret;
 366}
 367
 368static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 369{
 370	struct inode *inode = file_inode(file);
 371
 372	return put_user(inode->i_generation, arg);
 373}
 374
 375static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 376{
 377	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
 
 378	struct btrfs_device *device;
 379	struct request_queue *q;
 380	struct fstrim_range range;
 381	u64 minlen = ULLONG_MAX;
 382	u64 num_devices = 0;
 383	u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 384	int ret;
 385
 386	if (!capable(CAP_SYS_ADMIN))
 387		return -EPERM;
 388
 389	rcu_read_lock();
 390	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 391				dev_list) {
 392		if (!device->bdev)
 393			continue;
 394		q = bdev_get_queue(device->bdev);
 395		if (blk_queue_discard(q)) {
 396			num_devices++;
 397			minlen = min((u64)q->limits.discard_granularity,
 398				     minlen);
 399		}
 400	}
 401	rcu_read_unlock();
 402
 403	if (!num_devices)
 404		return -EOPNOTSUPP;
 
 405	if (copy_from_user(&range, arg, sizeof(range)))
 406		return -EFAULT;
 407	if (range.start > total_bytes ||
 408	    range.len < fs_info->sb->s_blocksize)
 409		return -EINVAL;
 410
 411	range.len = min(range.len, total_bytes - range.start);
 412	range.minlen = max(range.minlen, minlen);
 413	ret = btrfs_trim_fs(fs_info->tree_root, &range);
 414	if (ret < 0)
 415		return ret;
 416
 417	if (copy_to_user(arg, &range, sizeof(range)))
 418		return -EFAULT;
 419
 420	return 0;
 421}
 422
 423int btrfs_is_empty_uuid(u8 *uuid)
 424{
 425	int i;
 426
 427	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 428		if (uuid[i])
 429			return 0;
 430	}
 431	return 1;
 432}
 433
 434static noinline int create_subvol(struct inode *dir,
 435				  struct dentry *dentry,
 436				  char *name, int namelen,
 437				  u64 *async_transid,
 438				  struct btrfs_qgroup_inherit *inherit)
 439{
 440	struct btrfs_trans_handle *trans;
 441	struct btrfs_key key;
 442	struct btrfs_root_item root_item;
 443	struct btrfs_inode_item *inode_item;
 444	struct extent_buffer *leaf;
 445	struct btrfs_root *root = BTRFS_I(dir)->root;
 446	struct btrfs_root *new_root;
 447	struct btrfs_block_rsv block_rsv;
 448	struct timespec cur_time = current_fs_time(dir->i_sb);
 449	struct inode *inode;
 450	int ret;
 451	int err;
 452	u64 objectid;
 453	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 454	u64 index = 0;
 455	u64 qgroup_reserved;
 456	uuid_le new_uuid;
 457
 458	ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 459	if (ret)
 460		return ret;
 461
 462	/*
 463	 * Don't create subvolume whose level is not zero. Or qgroup will be
 464	 * screwed up since it assume subvolme qgroup's level to be 0.
 465	 */
 466	if (btrfs_qgroup_level(objectid))
 467		return -ENOSPC;
 468
 469	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 470	/*
 471	 * The same as the snapshot creation, please see the comment
 472	 * of create_snapshot().
 
 
 473	 */
 474	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 475					       8, &qgroup_reserved, false);
 476	if (ret)
 477		return ret;
 478
 479	trans = btrfs_start_transaction(root, 0);
 480	if (IS_ERR(trans)) {
 481		ret = PTR_ERR(trans);
 482		btrfs_subvolume_release_metadata(root, &block_rsv,
 483						 qgroup_reserved);
 484		return ret;
 485	}
 486	trans->block_rsv = &block_rsv;
 487	trans->bytes_reserved = block_rsv.size;
 488
 489	ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
 490	if (ret)
 491		goto fail;
 492
 493	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 494	if (IS_ERR(leaf)) {
 495		ret = PTR_ERR(leaf);
 496		goto fail;
 497	}
 498
 499	memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 500	btrfs_set_header_bytenr(leaf, leaf->start);
 501	btrfs_set_header_generation(leaf, trans->transid);
 502	btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 503	btrfs_set_header_owner(leaf, objectid);
 504
 505	write_extent_buffer(leaf, root->fs_info->fsid, btrfs_header_fsid(),
 
 506			    BTRFS_FSID_SIZE);
 507	write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 508			    btrfs_header_chunk_tree_uuid(leaf),
 509			    BTRFS_UUID_SIZE);
 510	btrfs_mark_buffer_dirty(leaf);
 511
 512	memset(&root_item, 0, sizeof(root_item));
 513
 514	inode_item = &root_item.inode;
 515	btrfs_set_stack_inode_generation(inode_item, 1);
 516	btrfs_set_stack_inode_size(inode_item, 3);
 517	btrfs_set_stack_inode_nlink(inode_item, 1);
 518	btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
 519	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 520
 521	btrfs_set_root_flags(&root_item, 0);
 522	btrfs_set_root_limit(&root_item, 0);
 523	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 
 524
 525	btrfs_set_root_bytenr(&root_item, leaf->start);
 526	btrfs_set_root_generation(&root_item, trans->transid);
 527	btrfs_set_root_level(&root_item, 0);
 528	btrfs_set_root_refs(&root_item, 1);
 529	btrfs_set_root_used(&root_item, leaf->len);
 530	btrfs_set_root_last_snapshot(&root_item, 0);
 531
 532	btrfs_set_root_generation_v2(&root_item,
 533			btrfs_root_generation(&root_item));
 534	uuid_le_gen(&new_uuid);
 535	memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
 536	btrfs_set_stack_timespec_sec(&root_item.otime, cur_time.tv_sec);
 537	btrfs_set_stack_timespec_nsec(&root_item.otime, cur_time.tv_nsec);
 538	root_item.ctime = root_item.otime;
 539	btrfs_set_root_ctransid(&root_item, trans->transid);
 540	btrfs_set_root_otransid(&root_item, trans->transid);
 541
 542	btrfs_tree_unlock(leaf);
 543	free_extent_buffer(leaf);
 544	leaf = NULL;
 545
 546	btrfs_set_root_dirid(&root_item, new_dirid);
 547
 548	key.objectid = objectid;
 549	key.offset = 0;
 550	key.type = BTRFS_ROOT_ITEM_KEY;
 551	ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 552				&root_item);
 553	if (ret)
 554		goto fail;
 555
 556	key.offset = (u64)-1;
 557	new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 558	if (IS_ERR(new_root)) {
 559		ret = PTR_ERR(new_root);
 560		btrfs_abort_transaction(trans, root, ret);
 561		goto fail;
 562	}
 563
 564	btrfs_record_root_in_trans(trans, new_root);
 565
 566	ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 567	if (ret) {
 568		/* We potentially lose an unused inode item here */
 569		btrfs_abort_transaction(trans, root, ret);
 570		goto fail;
 571	}
 572
 573	mutex_lock(&new_root->objectid_mutex);
 574	new_root->highest_objectid = new_dirid;
 575	mutex_unlock(&new_root->objectid_mutex);
 576
 577	/*
 578	 * insert the directory item
 579	 */
 580	ret = btrfs_set_inode_index(dir, &index);
 581	if (ret) {
 582		btrfs_abort_transaction(trans, root, ret);
 583		goto fail;
 584	}
 585
 586	ret = btrfs_insert_dir_item(trans, root,
 587				    name, namelen, dir, &key,
 588				    BTRFS_FT_DIR, index);
 589	if (ret) {
 590		btrfs_abort_transaction(trans, root, ret);
 591		goto fail;
 592	}
 593
 594	btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 595	ret = btrfs_update_inode(trans, root, dir);
 596	BUG_ON(ret);
 597
 598	ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 599				 objectid, root->root_key.objectid,
 600				 btrfs_ino(dir), index, name, namelen);
 
 601	BUG_ON(ret);
 602
 603	ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
 604				  root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
 605				  objectid);
 606	if (ret)
 607		btrfs_abort_transaction(trans, root, ret);
 608
 609fail:
 610	trans->block_rsv = NULL;
 611	trans->bytes_reserved = 0;
 612	btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
 613
 614	if (async_transid) {
 615		*async_transid = trans->transid;
 616		err = btrfs_commit_transaction_async(trans, root, 1);
 617		if (err)
 618			err = btrfs_commit_transaction(trans, root);
 619	} else {
 620		err = btrfs_commit_transaction(trans, root);
 621	}
 622	if (err && !ret)
 623		ret = err;
 624
 625	if (!ret) {
 626		inode = btrfs_lookup_dentry(dir, dentry);
 627		if (IS_ERR(inode))
 628			return PTR_ERR(inode);
 629		d_instantiate(dentry, inode);
 630	}
 631	return ret;
 632}
 633
 634static void btrfs_wait_for_no_snapshoting_writes(struct btrfs_root *root)
 635{
 636	s64 writers;
 637	DEFINE_WAIT(wait);
 638
 639	do {
 640		prepare_to_wait(&root->subv_writers->wait, &wait,
 641				TASK_UNINTERRUPTIBLE);
 642
 643		writers = percpu_counter_sum(&root->subv_writers->counter);
 644		if (writers)
 645			schedule();
 646
 647		finish_wait(&root->subv_writers->wait, &wait);
 648	} while (writers);
 649}
 650
 651static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 652			   struct dentry *dentry, char *name, int namelen,
 653			   u64 *async_transid, bool readonly,
 654			   struct btrfs_qgroup_inherit *inherit)
 655{
 656	struct inode *inode;
 657	struct btrfs_pending_snapshot *pending_snapshot;
 658	struct btrfs_trans_handle *trans;
 659	int ret;
 660
 661	if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 662		return -EINVAL;
 663
 664	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 665	if (!pending_snapshot)
 666		return -ENOMEM;
 667
 668	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 669			GFP_NOFS);
 670	pending_snapshot->path = btrfs_alloc_path();
 671	if (!pending_snapshot->root_item || !pending_snapshot->path) {
 672		ret = -ENOMEM;
 673		goto free_pending;
 674	}
 675
 676	atomic_inc(&root->will_be_snapshoted);
 677	smp_mb__after_atomic();
 678	btrfs_wait_for_no_snapshoting_writes(root);
 679
 680	ret = btrfs_start_delalloc_inodes(root, 0);
 681	if (ret)
 682		goto dec_and_free;
 683
 684	btrfs_wait_ordered_extents(root, -1);
 685
 686	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 687			     BTRFS_BLOCK_RSV_TEMP);
 688	/*
 689	 * 1 - parent dir inode
 690	 * 2 - dir entries
 691	 * 1 - root item
 692	 * 2 - root ref/backref
 693	 * 1 - root of snapshot
 694	 * 1 - UUID item
 695	 */
 696	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 697					&pending_snapshot->block_rsv, 8,
 698					&pending_snapshot->qgroup_reserved,
 699					false);
 700	if (ret)
 701		goto dec_and_free;
 702
 703	pending_snapshot->dentry = dentry;
 704	pending_snapshot->root = root;
 705	pending_snapshot->readonly = readonly;
 706	pending_snapshot->dir = dir;
 707	pending_snapshot->inherit = inherit;
 708
 709	trans = btrfs_start_transaction(root, 0);
 710	if (IS_ERR(trans)) {
 711		ret = PTR_ERR(trans);
 712		goto fail;
 713	}
 714
 
 
 
 715	spin_lock(&root->fs_info->trans_lock);
 716	list_add(&pending_snapshot->list,
 717		 &trans->transaction->pending_snapshots);
 718	spin_unlock(&root->fs_info->trans_lock);
 719	if (async_transid) {
 720		*async_transid = trans->transid;
 721		ret = btrfs_commit_transaction_async(trans,
 722				     root->fs_info->extent_root, 1);
 723		if (ret)
 724			ret = btrfs_commit_transaction(trans, root);
 725	} else {
 726		ret = btrfs_commit_transaction(trans,
 727					       root->fs_info->extent_root);
 728	}
 729	if (ret)
 730		goto fail;
 731
 732	ret = pending_snapshot->error;
 733	if (ret)
 734		goto fail;
 735
 736	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 737	if (ret)
 738		goto fail;
 739
 740	inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 741	if (IS_ERR(inode)) {
 742		ret = PTR_ERR(inode);
 743		goto fail;
 744	}
 745
 746	d_instantiate(dentry, inode);
 747	ret = 0;
 748fail:
 749	btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,
 750					 &pending_snapshot->block_rsv,
 751					 pending_snapshot->qgroup_reserved);
 752dec_and_free:
 753	if (atomic_dec_and_test(&root->will_be_snapshoted))
 754		wake_up_atomic_t(&root->will_be_snapshoted);
 755free_pending:
 756	kfree(pending_snapshot->root_item);
 757	btrfs_free_path(pending_snapshot->path);
 758	kfree(pending_snapshot);
 
 
 759
 760	return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 761}
 762
 763/*  copy of may_delete in fs/namei.c()
 764 *	Check whether we can remove a link victim from directory dir, check
 765 *  whether the type of victim is right.
 766 *  1. We can't do it if dir is read-only (done in permission())
 767 *  2. We should have write and exec permissions on dir
 768 *  3. We can't remove anything from append-only dir
 769 *  4. We can't do anything with immutable dir (done in permission())
 770 *  5. If the sticky bit on dir is set we should either
 771 *	a. be owner of dir, or
 772 *	b. be owner of victim, or
 773 *	c. have CAP_FOWNER capability
 774 *  6. If the victim is append-only or immutable we can't do antyhing with
 775 *     links pointing to it.
 776 *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 777 *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 778 *  9. We can't remove a root or mountpoint.
 779 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 780 *     nfs_async_unlink().
 781 */
 782
 783static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 784{
 785	int error;
 786
 787	if (d_really_is_negative(victim))
 788		return -ENOENT;
 789
 790	BUG_ON(d_inode(victim->d_parent) != dir);
 791	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 792
 793	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 794	if (error)
 795		return error;
 796	if (IS_APPEND(dir))
 797		return -EPERM;
 798	if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 799	    IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 
 800		return -EPERM;
 801	if (isdir) {
 802		if (!d_is_dir(victim))
 803			return -ENOTDIR;
 804		if (IS_ROOT(victim))
 805			return -EBUSY;
 806	} else if (d_is_dir(victim))
 807		return -EISDIR;
 808	if (IS_DEADDIR(dir))
 809		return -ENOENT;
 810	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 811		return -EBUSY;
 812	return 0;
 813}
 814
 815/* copy of may_create in fs/namei.c() */
 816static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 817{
 818	if (d_really_is_positive(child))
 819		return -EEXIST;
 820	if (IS_DEADDIR(dir))
 821		return -ENOENT;
 822	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 823}
 824
 825/*
 826 * Create a new subvolume below @parent.  This is largely modeled after
 827 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 828 * inside this filesystem so it's quite a bit simpler.
 829 */
 830static noinline int btrfs_mksubvol(struct path *parent,
 831				   char *name, int namelen,
 832				   struct btrfs_root *snap_src,
 833				   u64 *async_transid, bool readonly,
 834				   struct btrfs_qgroup_inherit *inherit)
 835{
 836	struct inode *dir  = d_inode(parent->dentry);
 837	struct dentry *dentry;
 838	int error;
 839
 840	error = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
 841	if (error == -EINTR)
 842		return error;
 843
 844	dentry = lookup_one_len(name, parent->dentry, namelen);
 845	error = PTR_ERR(dentry);
 846	if (IS_ERR(dentry))
 847		goto out_unlock;
 848
 849	error = btrfs_may_create(dir, dentry);
 
 
 
 
 850	if (error)
 851		goto out_dput;
 852
 853	/*
 854	 * even if this name doesn't exist, we may get hash collisions.
 855	 * check for them now when we can safely fail
 856	 */
 857	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 858					       dir->i_ino, name,
 859					       namelen);
 860	if (error)
 861		goto out_dput;
 862
 863	down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 864
 865	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 866		goto out_up_read;
 867
 868	if (snap_src) {
 869		error = create_snapshot(snap_src, dir, dentry, name, namelen,
 870					async_transid, readonly, inherit);
 871	} else {
 872		error = create_subvol(dir, dentry, name, namelen,
 873				      async_transid, inherit);
 874	}
 875	if (!error)
 876		fsnotify_mkdir(dir, dentry);
 877out_up_read:
 878	up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 
 
 879out_dput:
 880	dput(dentry);
 881out_unlock:
 882	inode_unlock(dir);
 883	return error;
 884}
 885
 886/*
 887 * When we're defragging a range, we don't want to kick it off again
 888 * if it is really just waiting for delalloc to send it down.
 889 * If we find a nice big extent or delalloc range for the bytes in the
 890 * file you want to defrag, we return 0 to let you know to skip this
 891 * part of the file
 892 */
 893static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 894{
 895	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 896	struct extent_map *em = NULL;
 897	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 898	u64 end;
 899
 900	read_lock(&em_tree->lock);
 901	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 902	read_unlock(&em_tree->lock);
 903
 904	if (em) {
 905		end = extent_map_end(em);
 906		free_extent_map(em);
 907		if (end - offset > thresh)
 908			return 0;
 909	}
 910	/* if we already have a nice delalloc here, just stop */
 911	thresh /= 2;
 912	end = count_range_bits(io_tree, &offset, offset + thresh,
 913			       thresh, EXTENT_DELALLOC, 1);
 914	if (end >= thresh)
 915		return 0;
 916	return 1;
 917}
 918
 919/*
 920 * helper function to walk through a file and find extents
 921 * newer than a specific transid, and smaller than thresh.
 922 *
 923 * This is used by the defragging code to find new and small
 924 * extents
 925 */
 926static int find_new_extents(struct btrfs_root *root,
 927			    struct inode *inode, u64 newer_than,
 928			    u64 *off, u32 thresh)
 929{
 930	struct btrfs_path *path;
 931	struct btrfs_key min_key;
 
 932	struct extent_buffer *leaf;
 933	struct btrfs_file_extent_item *extent;
 934	int type;
 935	int ret;
 936	u64 ino = btrfs_ino(inode);
 937
 938	path = btrfs_alloc_path();
 939	if (!path)
 940		return -ENOMEM;
 941
 942	min_key.objectid = ino;
 943	min_key.type = BTRFS_EXTENT_DATA_KEY;
 944	min_key.offset = *off;
 945
 946	while (1) {
 947		ret = btrfs_search_forward(root, &min_key, path, newer_than);
 
 
 
 
 
 
 
 948		if (ret != 0)
 949			goto none;
 950process_slot:
 951		if (min_key.objectid != ino)
 952			goto none;
 953		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 954			goto none;
 955
 956		leaf = path->nodes[0];
 957		extent = btrfs_item_ptr(leaf, path->slots[0],
 958					struct btrfs_file_extent_item);
 959
 960		type = btrfs_file_extent_type(leaf, extent);
 961		if (type == BTRFS_FILE_EXTENT_REG &&
 962		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 963		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
 964			*off = min_key.offset;
 965			btrfs_free_path(path);
 966			return 0;
 967		}
 968
 969		path->slots[0]++;
 970		if (path->slots[0] < btrfs_header_nritems(leaf)) {
 971			btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 972			goto process_slot;
 973		}
 974
 975		if (min_key.offset == (u64)-1)
 976			goto none;
 977
 978		min_key.offset++;
 979		btrfs_release_path(path);
 980	}
 981none:
 982	btrfs_free_path(path);
 983	return -ENOENT;
 984}
 985
 986static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 
 
 987{
 
 
 988	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 989	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 990	struct extent_map *em;
 991	u64 len = PAGE_SIZE;
 
 
 
 
 
 
 
 992
 993	/*
 994	 * hopefully we have this extent in the tree already, try without
 995	 * the full extent lock
 996	 */
 997	read_lock(&em_tree->lock);
 998	em = lookup_extent_mapping(em_tree, start, len);
 999	read_unlock(&em_tree->lock);
1000
1001	if (!em) {
1002		struct extent_state *cached = NULL;
1003		u64 end = start + len - 1;
1004
1005		/* get the big lock and read metadata off disk */
1006		lock_extent_bits(io_tree, start, end, &cached);
1007		em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
1008		unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
1009
1010		if (IS_ERR(em))
1011			return NULL;
1012	}
1013
1014	return em;
1015}
1016
1017static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1018{
1019	struct extent_map *next;
1020	bool ret = true;
1021
1022	/* this is the last extent */
1023	if (em->start + em->len >= i_size_read(inode))
1024		return false;
1025
1026	next = defrag_lookup_extent(inode, em->start + em->len);
1027	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1028		ret = false;
1029	else if ((em->block_start + em->block_len == next->block_start) &&
1030		 (em->block_len > SZ_128K && next->block_len > SZ_128K))
1031		ret = false;
1032
1033	free_extent_map(next);
1034	return ret;
1035}
1036
1037static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1038			       u64 *last_len, u64 *skip, u64 *defrag_end,
1039			       int compress)
1040{
1041	struct extent_map *em;
1042	int ret = 1;
1043	bool next_mergeable = true;
1044	bool prev_mergeable = true;
1045
1046	/*
1047	 * make sure that once we start defragging an extent, we keep on
1048	 * defragging it
1049	 */
1050	if (start < *defrag_end)
1051		return 1;
1052
1053	*skip = 0;
1054
1055	em = defrag_lookup_extent(inode, start);
1056	if (!em)
1057		return 0;
1058
1059	/* this will cover holes, and inline extents */
1060	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1061		ret = 0;
1062		goto out;
1063	}
1064
1065	if (!*defrag_end)
1066		prev_mergeable = false;
1067
1068	next_mergeable = defrag_check_next_extent(inode, em);
1069	/*
1070	 * we hit a real extent, if it is big or the next extent is not a
1071	 * real extent, don't bother defragging it
1072	 */
1073	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1074	    (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1075		ret = 0;
1076out:
1077	/*
1078	 * last_len ends up being a counter of how many bytes we've defragged.
1079	 * every time we choose not to defrag an extent, we reset *last_len
1080	 * so that the next tiny extent will force a defrag.
1081	 *
1082	 * The end result of this is that tiny extents before a single big
1083	 * extent will force at least part of that big extent to be defragged.
1084	 */
1085	if (ret) {
 
1086		*defrag_end = extent_map_end(em);
1087	} else {
1088		*last_len = 0;
1089		*skip = extent_map_end(em);
1090		*defrag_end = 0;
1091	}
1092
1093	free_extent_map(em);
1094	return ret;
1095}
1096
1097/*
1098 * it doesn't do much good to defrag one or two pages
1099 * at a time.  This pulls in a nice chunk of pages
1100 * to COW and defrag.
1101 *
1102 * It also makes sure the delalloc code has enough
1103 * dirty data to avoid making new small extents as part
1104 * of the defrag
1105 *
1106 * It's a good idea to start RA on this range
1107 * before calling this.
1108 */
1109static int cluster_pages_for_defrag(struct inode *inode,
1110				    struct page **pages,
1111				    unsigned long start_index,
1112				    unsigned long num_pages)
1113{
1114	unsigned long file_end;
1115	u64 isize = i_size_read(inode);
1116	u64 page_start;
1117	u64 page_end;
1118	u64 page_cnt;
1119	int ret;
1120	int i;
1121	int i_done;
1122	struct btrfs_ordered_extent *ordered;
1123	struct extent_state *cached_state = NULL;
1124	struct extent_io_tree *tree;
1125	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1126
1127	file_end = (isize - 1) >> PAGE_SHIFT;
1128	if (!isize || start_index > file_end)
1129		return 0;
1130
1131	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1132
1133	ret = btrfs_delalloc_reserve_space(inode,
1134			start_index << PAGE_SHIFT,
1135			page_cnt << PAGE_SHIFT);
1136	if (ret)
1137		return ret;
 
 
1138	i_done = 0;
1139	tree = &BTRFS_I(inode)->io_tree;
1140
1141	/* step one, lock all the pages */
1142	for (i = 0; i < page_cnt; i++) {
1143		struct page *page;
1144again:
1145		page = find_or_create_page(inode->i_mapping,
1146					   start_index + i, mask);
1147		if (!page)
1148			break;
1149
1150		page_start = page_offset(page);
1151		page_end = page_start + PAGE_SIZE - 1;
1152		while (1) {
1153			lock_extent_bits(tree, page_start, page_end,
1154					 &cached_state);
1155			ordered = btrfs_lookup_ordered_extent(inode,
1156							      page_start);
1157			unlock_extent_cached(tree, page_start, page_end,
1158					     &cached_state, GFP_NOFS);
1159			if (!ordered)
1160				break;
1161
1162			unlock_page(page);
1163			btrfs_start_ordered_extent(inode, ordered, 1);
1164			btrfs_put_ordered_extent(ordered);
1165			lock_page(page);
1166			/*
1167			 * we unlocked the page above, so we need check if
1168			 * it was released or not.
1169			 */
1170			if (page->mapping != inode->i_mapping) {
1171				unlock_page(page);
1172				put_page(page);
1173				goto again;
1174			}
1175		}
1176
1177		if (!PageUptodate(page)) {
1178			btrfs_readpage(NULL, page);
1179			lock_page(page);
1180			if (!PageUptodate(page)) {
1181				unlock_page(page);
1182				put_page(page);
1183				ret = -EIO;
1184				break;
1185			}
1186		}
1187
1188		if (page->mapping != inode->i_mapping) {
 
 
 
1189			unlock_page(page);
1190			put_page(page);
1191			goto again;
1192		}
1193
1194		pages[i] = page;
1195		i_done++;
1196	}
1197	if (!i_done || ret)
1198		goto out;
1199
1200	if (!(inode->i_sb->s_flags & MS_ACTIVE))
1201		goto out;
1202
1203	/*
1204	 * so now we have a nice long stream of locked
1205	 * and up to date pages, lets wait on them
1206	 */
1207	for (i = 0; i < i_done; i++)
1208		wait_on_page_writeback(pages[i]);
1209
1210	page_start = page_offset(pages[0]);
1211	page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1212
1213	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1214			 page_start, page_end - 1, &cached_state);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1215	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1216			  page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1217			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1218			  &cached_state, GFP_NOFS);
1219
1220	if (i_done != page_cnt) {
1221		spin_lock(&BTRFS_I(inode)->lock);
1222		BTRFS_I(inode)->outstanding_extents++;
1223		spin_unlock(&BTRFS_I(inode)->lock);
1224		btrfs_delalloc_release_space(inode,
1225				start_index << PAGE_SHIFT,
1226				(page_cnt - i_done) << PAGE_SHIFT);
1227	}
1228
1229
1230	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1231			  &cached_state, GFP_NOFS);
1232
1233	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1234			     page_start, page_end - 1, &cached_state,
1235			     GFP_NOFS);
1236
1237	for (i = 0; i < i_done; i++) {
1238		clear_page_dirty_for_io(pages[i]);
1239		ClearPageChecked(pages[i]);
1240		set_page_extent_mapped(pages[i]);
1241		set_page_dirty(pages[i]);
1242		unlock_page(pages[i]);
1243		put_page(pages[i]);
1244	}
1245	return i_done;
1246out:
1247	for (i = 0; i < i_done; i++) {
1248		unlock_page(pages[i]);
1249		put_page(pages[i]);
1250	}
1251	btrfs_delalloc_release_space(inode,
1252			start_index << PAGE_SHIFT,
1253			page_cnt << PAGE_SHIFT);
1254	return ret;
1255
1256}
1257
1258int btrfs_defrag_file(struct inode *inode, struct file *file,
1259		      struct btrfs_ioctl_defrag_range_args *range,
1260		      u64 newer_than, unsigned long max_to_defrag)
1261{
1262	struct btrfs_root *root = BTRFS_I(inode)->root;
 
1263	struct file_ra_state *ra = NULL;
1264	unsigned long last_index;
1265	u64 isize = i_size_read(inode);
1266	u64 last_len = 0;
1267	u64 skip = 0;
1268	u64 defrag_end = 0;
1269	u64 newer_off = range->start;
 
1270	unsigned long i;
1271	unsigned long ra_index = 0;
1272	int ret;
1273	int defrag_count = 0;
1274	int compress_type = BTRFS_COMPRESS_ZLIB;
1275	u32 extent_thresh = range->extent_thresh;
1276	unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1277	unsigned long cluster = max_cluster;
1278	u64 new_align = ~((u64)SZ_128K - 1);
1279	struct page **pages = NULL;
1280
1281	if (isize == 0)
1282		return 0;
1283
1284	if (range->start >= isize)
1285		return -EINVAL;
1286
1287	if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1288		if (range->compress_type > BTRFS_COMPRESS_TYPES)
1289			return -EINVAL;
1290		if (range->compress_type)
1291			compress_type = range->compress_type;
1292	}
1293
1294	if (extent_thresh == 0)
1295		extent_thresh = SZ_256K;
1296
1297	/*
1298	 * if we were not given a file, allocate a readahead
1299	 * context
1300	 */
1301	if (!file) {
1302		ra = kzalloc(sizeof(*ra), GFP_NOFS);
1303		if (!ra)
1304			return -ENOMEM;
1305		file_ra_state_init(ra, inode->i_mapping);
1306	} else {
1307		ra = &file->f_ra;
1308	}
1309
1310	pages = kmalloc_array(max_cluster, sizeof(struct page *),
1311			GFP_NOFS);
1312	if (!pages) {
1313		ret = -ENOMEM;
1314		goto out_ra;
1315	}
1316
1317	/* find the last page to defrag */
1318	if (range->start + range->len > range->start) {
1319		last_index = min_t(u64, isize - 1,
1320			 range->start + range->len - 1) >> PAGE_SHIFT;
1321	} else {
1322		last_index = (isize - 1) >> PAGE_SHIFT;
1323	}
1324
1325	if (newer_than) {
1326		ret = find_new_extents(root, inode, newer_than,
1327				       &newer_off, SZ_64K);
1328		if (!ret) {
1329			range->start = newer_off;
1330			/*
1331			 * we always align our defrag to help keep
1332			 * the extents in the file evenly spaced
1333			 */
1334			i = (newer_off & new_align) >> PAGE_SHIFT;
 
1335		} else
1336			goto out_ra;
1337	} else {
1338		i = range->start >> PAGE_SHIFT;
1339	}
1340	if (!max_to_defrag)
1341		max_to_defrag = last_index - i + 1;
1342
1343	/*
1344	 * make writeback starts from i, so the defrag range can be
1345	 * written sequentially.
1346	 */
1347	if (i < inode->i_mapping->writeback_index)
1348		inode->i_mapping->writeback_index = i;
1349
1350	while (i <= last_index && defrag_count < max_to_defrag &&
1351	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
 
1352		/*
1353		 * make sure we stop running if someone unmounts
1354		 * the FS
1355		 */
1356		if (!(inode->i_sb->s_flags & MS_ACTIVE))
1357			break;
1358
1359		if (btrfs_defrag_cancelled(root->fs_info)) {
1360			btrfs_debug(root->fs_info, "defrag_file cancelled");
1361			ret = -EAGAIN;
1362			break;
1363		}
1364
1365		if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1366					 extent_thresh, &last_len, &skip,
1367					 &defrag_end, range->flags &
1368					 BTRFS_DEFRAG_RANGE_COMPRESS)) {
1369			unsigned long next;
1370			/*
1371			 * the should_defrag function tells us how much to skip
1372			 * bump our counter by the suggested amount
1373			 */
1374			next = DIV_ROUND_UP(skip, PAGE_SIZE);
1375			i = max(i + 1, next);
1376			continue;
1377		}
 
 
1378
1379		if (!newer_than) {
1380			cluster = (PAGE_ALIGN(defrag_end) >>
1381				   PAGE_SHIFT) - i;
1382			cluster = min(cluster, max_cluster);
1383		} else {
1384			cluster = max_cluster;
1385		}
1386
1387		if (i + cluster > ra_index) {
1388			ra_index = max(i, ra_index);
1389			btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1390				       cluster);
1391			ra_index += cluster;
1392		}
1393
1394		inode_lock(inode);
1395		if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1396			BTRFS_I(inode)->force_compress = compress_type;
1397		ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1398		if (ret < 0) {
1399			inode_unlock(inode);
1400			goto out_ra;
1401		}
1402
1403		defrag_count += ret;
1404		balance_dirty_pages_ratelimited(inode->i_mapping);
1405		inode_unlock(inode);
1406
1407		if (newer_than) {
1408			if (newer_off == (u64)-1)
1409				break;
1410
1411			if (ret > 0)
1412				i += ret;
1413
1414			newer_off = max(newer_off + 1,
1415					(u64)i << PAGE_SHIFT);
1416
1417			ret = find_new_extents(root, inode, newer_than,
1418					       &newer_off, SZ_64K);
 
1419			if (!ret) {
1420				range->start = newer_off;
1421				i = (newer_off & new_align) >> PAGE_SHIFT;
 
1422			} else {
1423				break;
1424			}
1425		} else {
1426			if (ret > 0) {
1427				i += ret;
1428				last_len += ret << PAGE_SHIFT;
1429			} else {
1430				i++;
1431				last_len = 0;
1432			}
1433		}
1434	}
1435
1436	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1437		filemap_flush(inode->i_mapping);
1438		if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1439			     &BTRFS_I(inode)->runtime_flags))
1440			filemap_flush(inode->i_mapping);
1441	}
1442
1443	if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1444		/* the filemap_flush will queue IO into the worker threads, but
1445		 * we have to make sure the IO is actually started and that
1446		 * ordered extents get created before we return
1447		 */
1448		atomic_inc(&root->fs_info->async_submit_draining);
1449		while (atomic_read(&root->fs_info->nr_async_submits) ||
1450		      atomic_read(&root->fs_info->async_delalloc_pages)) {
1451			wait_event(root->fs_info->async_submit_wait,
1452			   (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1453			    atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1454		}
1455		atomic_dec(&root->fs_info->async_submit_draining);
 
 
 
 
1456	}
1457
 
 
1458	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1459		btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
 
1460	}
1461
1462	ret = defrag_count;
 
 
1463
1464out_ra:
1465	if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1466		inode_lock(inode);
1467		BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1468		inode_unlock(inode);
1469	}
1470	if (!file)
1471		kfree(ra);
1472	kfree(pages);
1473	return ret;
1474}
1475
1476static noinline int btrfs_ioctl_resize(struct file *file,
1477					void __user *arg)
1478{
1479	u64 new_size;
1480	u64 old_size;
1481	u64 devid = 1;
1482	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
1483	struct btrfs_ioctl_vol_args *vol_args;
1484	struct btrfs_trans_handle *trans;
1485	struct btrfs_device *device = NULL;
1486	char *sizestr;
1487	char *retptr;
1488	char *devstr = NULL;
1489	int ret = 0;
1490	int mod = 0;
1491
 
 
 
1492	if (!capable(CAP_SYS_ADMIN))
1493		return -EPERM;
1494
1495	ret = mnt_want_write_file(file);
1496	if (ret)
1497		return ret;
1498
1499	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1500			1)) {
1501		mnt_drop_write_file(file);
1502		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1503	}
1504
1505	mutex_lock(&root->fs_info->volume_mutex);
1506	vol_args = memdup_user(arg, sizeof(*vol_args));
1507	if (IS_ERR(vol_args)) {
1508		ret = PTR_ERR(vol_args);
1509		goto out;
1510	}
1511
1512	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1513
 
1514	sizestr = vol_args->name;
1515	devstr = strchr(sizestr, ':');
1516	if (devstr) {
 
1517		sizestr = devstr + 1;
1518		*devstr = '\0';
1519		devstr = vol_args->name;
1520		ret = kstrtoull(devstr, 10, &devid);
1521		if (ret)
1522			goto out_free;
1523		if (!devid) {
1524			ret = -EINVAL;
1525			goto out_free;
1526		}
1527		btrfs_info(root->fs_info, "resizing devid %llu", devid);
1528	}
1529
1530	device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1531	if (!device) {
1532		btrfs_info(root->fs_info, "resizer unable to find device %llu",
1533		       devid);
1534		ret = -ENODEV;
1535		goto out_free;
1536	}
1537
1538	if (!device->writeable) {
1539		btrfs_info(root->fs_info,
1540			   "resizer unable to apply on readonly device %llu",
1541		       devid);
1542		ret = -EPERM;
1543		goto out_free;
1544	}
1545
1546	if (!strcmp(sizestr, "max"))
1547		new_size = device->bdev->bd_inode->i_size;
1548	else {
1549		if (sizestr[0] == '-') {
1550			mod = -1;
1551			sizestr++;
1552		} else if (sizestr[0] == '+') {
1553			mod = 1;
1554			sizestr++;
1555		}
1556		new_size = memparse(sizestr, &retptr);
1557		if (*retptr != '\0' || new_size == 0) {
1558			ret = -EINVAL;
1559			goto out_free;
1560		}
1561	}
1562
1563	if (device->is_tgtdev_for_dev_replace) {
1564		ret = -EPERM;
1565		goto out_free;
1566	}
1567
1568	old_size = btrfs_device_get_total_bytes(device);
1569
1570	if (mod < 0) {
1571		if (new_size > old_size) {
1572			ret = -EINVAL;
1573			goto out_free;
1574		}
1575		new_size = old_size - new_size;
1576	} else if (mod > 0) {
1577		if (new_size > ULLONG_MAX - old_size) {
1578			ret = -ERANGE;
1579			goto out_free;
1580		}
1581		new_size = old_size + new_size;
1582	}
1583
1584	if (new_size < SZ_256M) {
1585		ret = -EINVAL;
1586		goto out_free;
1587	}
1588	if (new_size > device->bdev->bd_inode->i_size) {
1589		ret = -EFBIG;
1590		goto out_free;
1591	}
1592
1593	new_size = div_u64(new_size, root->sectorsize);
1594	new_size *= root->sectorsize;
1595
1596	btrfs_info_in_rcu(root->fs_info, "new size for %s is %llu",
1597		      rcu_str_deref(device->name), new_size);
1598
1599	if (new_size > old_size) {
1600		trans = btrfs_start_transaction(root, 0);
1601		if (IS_ERR(trans)) {
1602			ret = PTR_ERR(trans);
1603			goto out_free;
1604		}
1605		ret = btrfs_grow_device(trans, device, new_size);
1606		btrfs_commit_transaction(trans, root);
1607	} else if (new_size < old_size) {
1608		ret = btrfs_shrink_device(device, new_size);
1609	} /* equal, nothing need to do */
1610
1611out_free:
 
1612	kfree(vol_args);
1613out:
1614	mutex_unlock(&root->fs_info->volume_mutex);
1615	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1616	mnt_drop_write_file(file);
1617	return ret;
1618}
1619
1620static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1621				char *name, unsigned long fd, int subvol,
1622				u64 *transid, bool readonly,
1623				struct btrfs_qgroup_inherit *inherit)
 
 
1624{
 
 
1625	int namelen;
1626	int ret = 0;
1627
1628	ret = mnt_want_write_file(file);
1629	if (ret)
1630		goto out;
1631
1632	namelen = strlen(name);
1633	if (strchr(name, '/')) {
1634		ret = -EINVAL;
1635		goto out_drop_write;
1636	}
1637
1638	if (name[0] == '.' &&
1639	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1640		ret = -EEXIST;
1641		goto out_drop_write;
1642	}
1643
1644	if (subvol) {
1645		ret = btrfs_mksubvol(&file->f_path, name, namelen,
1646				     NULL, transid, readonly, inherit);
1647	} else {
1648		struct fd src = fdget(fd);
1649		struct inode *src_inode;
1650		if (!src.file) {
 
1651			ret = -EINVAL;
1652			goto out_drop_write;
1653		}
1654
1655		src_inode = file_inode(src.file);
1656		if (src_inode->i_sb != file_inode(file)->i_sb) {
1657			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1658				   "Snapshot src from another FS");
1659			ret = -EXDEV;
1660		} else if (!inode_owner_or_capable(src_inode)) {
1661			/*
1662			 * Subvolume creation is not restricted, but snapshots
1663			 * are limited to own subvolumes only
1664			 */
1665			ret = -EPERM;
1666		} else {
1667			ret = btrfs_mksubvol(&file->f_path, name, namelen,
1668					     BTRFS_I(src_inode)->root,
1669					     transid, readonly, inherit);
1670		}
1671		fdput(src);
 
 
 
1672	}
1673out_drop_write:
1674	mnt_drop_write_file(file);
1675out:
1676	return ret;
1677}
1678
1679static noinline int btrfs_ioctl_snap_create(struct file *file,
1680					    void __user *arg, int subvol)
1681{
1682	struct btrfs_ioctl_vol_args *vol_args;
1683	int ret;
1684
1685	vol_args = memdup_user(arg, sizeof(*vol_args));
1686	if (IS_ERR(vol_args))
1687		return PTR_ERR(vol_args);
1688	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1689
1690	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1691					      vol_args->fd, subvol,
1692					      NULL, false, NULL);
1693
1694	kfree(vol_args);
1695	return ret;
1696}
1697
1698static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1699					       void __user *arg, int subvol)
1700{
1701	struct btrfs_ioctl_vol_args_v2 *vol_args;
1702	int ret;
1703	u64 transid = 0;
1704	u64 *ptr = NULL;
1705	bool readonly = false;
1706	struct btrfs_qgroup_inherit *inherit = NULL;
1707
1708	vol_args = memdup_user(arg, sizeof(*vol_args));
1709	if (IS_ERR(vol_args))
1710		return PTR_ERR(vol_args);
1711	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1712
1713	if (vol_args->flags &
1714	    ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1715	      BTRFS_SUBVOL_QGROUP_INHERIT)) {
1716		ret = -EOPNOTSUPP;
1717		goto free_args;
1718	}
1719
1720	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1721		ptr = &transid;
1722	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1723		readonly = true;
1724	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1725		if (vol_args->size > PAGE_SIZE) {
1726			ret = -EINVAL;
1727			goto free_args;
1728		}
1729		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1730		if (IS_ERR(inherit)) {
1731			ret = PTR_ERR(inherit);
1732			goto free_args;
1733		}
1734	}
1735
1736	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1737					      vol_args->fd, subvol, ptr,
1738					      readonly, inherit);
1739	if (ret)
1740		goto free_inherit;
1741
1742	if (ptr && copy_to_user(arg +
1743				offsetof(struct btrfs_ioctl_vol_args_v2,
1744					transid),
1745				ptr, sizeof(*ptr)))
1746		ret = -EFAULT;
1747
1748free_inherit:
1749	kfree(inherit);
1750free_args:
1751	kfree(vol_args);
1752	return ret;
1753}
1754
1755static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1756						void __user *arg)
1757{
1758	struct inode *inode = file_inode(file);
1759	struct btrfs_root *root = BTRFS_I(inode)->root;
1760	int ret = 0;
1761	u64 flags = 0;
1762
1763	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1764		return -EINVAL;
1765
1766	down_read(&root->fs_info->subvol_sem);
1767	if (btrfs_root_readonly(root))
1768		flags |= BTRFS_SUBVOL_RDONLY;
1769	up_read(&root->fs_info->subvol_sem);
1770
1771	if (copy_to_user(arg, &flags, sizeof(flags)))
1772		ret = -EFAULT;
1773
1774	return ret;
1775}
1776
1777static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1778					      void __user *arg)
1779{
1780	struct inode *inode = file_inode(file);
1781	struct btrfs_root *root = BTRFS_I(inode)->root;
1782	struct btrfs_trans_handle *trans;
1783	u64 root_flags;
1784	u64 flags;
1785	int ret = 0;
1786
1787	if (!inode_owner_or_capable(inode))
1788		return -EPERM;
1789
1790	ret = mnt_want_write_file(file);
1791	if (ret)
1792		goto out;
1793
1794	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1795		ret = -EINVAL;
1796		goto out_drop_write;
1797	}
1798
1799	if (copy_from_user(&flags, arg, sizeof(flags))) {
1800		ret = -EFAULT;
1801		goto out_drop_write;
1802	}
1803
1804	if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1805		ret = -EINVAL;
1806		goto out_drop_write;
1807	}
1808
1809	if (flags & ~BTRFS_SUBVOL_RDONLY) {
1810		ret = -EOPNOTSUPP;
1811		goto out_drop_write;
1812	}
1813
1814	down_write(&root->fs_info->subvol_sem);
1815
1816	/* nothing to do */
1817	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1818		goto out_drop_sem;
1819
1820	root_flags = btrfs_root_flags(&root->root_item);
1821	if (flags & BTRFS_SUBVOL_RDONLY) {
1822		btrfs_set_root_flags(&root->root_item,
1823				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1824	} else {
1825		/*
1826		 * Block RO -> RW transition if this subvolume is involved in
1827		 * send
1828		 */
1829		spin_lock(&root->root_item_lock);
1830		if (root->send_in_progress == 0) {
1831			btrfs_set_root_flags(&root->root_item,
1832				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1833			spin_unlock(&root->root_item_lock);
1834		} else {
1835			spin_unlock(&root->root_item_lock);
1836			btrfs_warn(root->fs_info,
1837			"Attempt to set subvolume %llu read-write during send",
1838					root->root_key.objectid);
1839			ret = -EPERM;
1840			goto out_drop_sem;
1841		}
1842	}
1843
1844	trans = btrfs_start_transaction(root, 1);
1845	if (IS_ERR(trans)) {
1846		ret = PTR_ERR(trans);
1847		goto out_reset;
1848	}
1849
1850	ret = btrfs_update_root(trans, root->fs_info->tree_root,
1851				&root->root_key, &root->root_item);
1852
1853	btrfs_commit_transaction(trans, root);
1854out_reset:
1855	if (ret)
1856		btrfs_set_root_flags(&root->root_item, root_flags);
1857out_drop_sem:
1858	up_write(&root->fs_info->subvol_sem);
1859out_drop_write:
1860	mnt_drop_write_file(file);
1861out:
1862	return ret;
1863}
1864
1865/*
1866 * helper to check if the subvolume references other subvolumes
1867 */
1868static noinline int may_destroy_subvol(struct btrfs_root *root)
1869{
1870	struct btrfs_path *path;
1871	struct btrfs_dir_item *di;
1872	struct btrfs_key key;
1873	u64 dir_id;
1874	int ret;
1875
1876	path = btrfs_alloc_path();
1877	if (!path)
1878		return -ENOMEM;
1879
1880	/* Make sure this root isn't set as the default subvol */
1881	dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
1882	di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, path,
1883				   dir_id, "default", 7, 0);
1884	if (di && !IS_ERR(di)) {
1885		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1886		if (key.objectid == root->root_key.objectid) {
1887			ret = -EPERM;
1888			btrfs_err(root->fs_info, "deleting default subvolume "
1889				  "%llu is not allowed", key.objectid);
1890			goto out;
1891		}
1892		btrfs_release_path(path);
1893	}
1894
1895	key.objectid = root->root_key.objectid;
1896	key.type = BTRFS_ROOT_REF_KEY;
1897	key.offset = (u64)-1;
1898
1899	ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1900				&key, path, 0, 0);
1901	if (ret < 0)
1902		goto out;
1903	BUG_ON(ret == 0);
1904
1905	ret = 0;
1906	if (path->slots[0] > 0) {
1907		path->slots[0]--;
1908		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1909		if (key.objectid == root->root_key.objectid &&
1910		    key.type == BTRFS_ROOT_REF_KEY)
1911			ret = -ENOTEMPTY;
1912	}
1913out:
1914	btrfs_free_path(path);
1915	return ret;
1916}
1917
1918static noinline int key_in_sk(struct btrfs_key *key,
1919			      struct btrfs_ioctl_search_key *sk)
1920{
1921	struct btrfs_key test;
1922	int ret;
1923
1924	test.objectid = sk->min_objectid;
1925	test.type = sk->min_type;
1926	test.offset = sk->min_offset;
1927
1928	ret = btrfs_comp_cpu_keys(key, &test);
1929	if (ret < 0)
1930		return 0;
1931
1932	test.objectid = sk->max_objectid;
1933	test.type = sk->max_type;
1934	test.offset = sk->max_offset;
1935
1936	ret = btrfs_comp_cpu_keys(key, &test);
1937	if (ret > 0)
1938		return 0;
1939	return 1;
1940}
1941
1942static noinline int copy_to_sk(struct btrfs_root *root,
1943			       struct btrfs_path *path,
1944			       struct btrfs_key *key,
1945			       struct btrfs_ioctl_search_key *sk,
1946			       size_t *buf_size,
1947			       char __user *ubuf,
1948			       unsigned long *sk_offset,
1949			       int *num_found)
1950{
1951	u64 found_transid;
1952	struct extent_buffer *leaf;
1953	struct btrfs_ioctl_search_header sh;
1954	struct btrfs_key test;
1955	unsigned long item_off;
1956	unsigned long item_len;
1957	int nritems;
1958	int i;
1959	int slot;
1960	int ret = 0;
1961
1962	leaf = path->nodes[0];
1963	slot = path->slots[0];
1964	nritems = btrfs_header_nritems(leaf);
1965
1966	if (btrfs_header_generation(leaf) > sk->max_transid) {
1967		i = nritems;
1968		goto advance_key;
1969	}
1970	found_transid = btrfs_header_generation(leaf);
1971
1972	for (i = slot; i < nritems; i++) {
1973		item_off = btrfs_item_ptr_offset(leaf, i);
1974		item_len = btrfs_item_size_nr(leaf, i);
1975
1976		btrfs_item_key_to_cpu(leaf, key, i);
1977		if (!key_in_sk(key, sk))
1978			continue;
1979
1980		if (sizeof(sh) + item_len > *buf_size) {
1981			if (*num_found) {
1982				ret = 1;
1983				goto out;
1984			}
1985
1986			/*
1987			 * return one empty item back for v1, which does not
1988			 * handle -EOVERFLOW
1989			 */
1990
1991			*buf_size = sizeof(sh) + item_len;
1992			item_len = 0;
1993			ret = -EOVERFLOW;
1994		}
1995
1996		if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
 
1997			ret = 1;
1998			goto out;
1999		}
2000
 
 
 
 
2001		sh.objectid = key->objectid;
2002		sh.offset = key->offset;
2003		sh.type = key->type;
2004		sh.len = item_len;
2005		sh.transid = found_transid;
2006
2007		/* copy search result header */
2008		if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2009			ret = -EFAULT;
2010			goto out;
2011		}
2012
2013		*sk_offset += sizeof(sh);
2014
2015		if (item_len) {
2016			char __user *up = ubuf + *sk_offset;
2017			/* copy the item */
2018			if (read_extent_buffer_to_user(leaf, up,
2019						       item_off, item_len)) {
2020				ret = -EFAULT;
2021				goto out;
2022			}
2023
2024			*sk_offset += item_len;
2025		}
2026		(*num_found)++;
2027
2028		if (ret) /* -EOVERFLOW from above */
2029			goto out;
2030
2031		if (*num_found >= sk->nr_items) {
2032			ret = 1;
2033			goto out;
2034		}
2035	}
2036advance_key:
2037	ret = 0;
2038	test.objectid = sk->max_objectid;
2039	test.type = sk->max_type;
2040	test.offset = sk->max_offset;
2041	if (btrfs_comp_cpu_keys(key, &test) >= 0)
2042		ret = 1;
2043	else if (key->offset < (u64)-1)
2044		key->offset++;
2045	else if (key->type < (u8)-1) {
2046		key->offset = 0;
2047		key->type++;
2048	} else if (key->objectid < (u64)-1) {
2049		key->offset = 0;
2050		key->type = 0;
2051		key->objectid++;
2052	} else
2053		ret = 1;
2054out:
2055	/*
2056	 *  0: all items from this leaf copied, continue with next
2057	 *  1: * more items can be copied, but unused buffer is too small
2058	 *     * all items were found
2059	 *     Either way, it will stops the loop which iterates to the next
2060	 *     leaf
2061	 *  -EOVERFLOW: item was to large for buffer
2062	 *  -EFAULT: could not copy extent buffer back to userspace
2063	 */
2064	return ret;
2065}
2066
2067static noinline int search_ioctl(struct inode *inode,
2068				 struct btrfs_ioctl_search_key *sk,
2069				 size_t *buf_size,
2070				 char __user *ubuf)
2071{
2072	struct btrfs_root *root;
2073	struct btrfs_key key;
 
2074	struct btrfs_path *path;
 
2075	struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
2076	int ret;
2077	int num_found = 0;
2078	unsigned long sk_offset = 0;
2079
2080	if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2081		*buf_size = sizeof(struct btrfs_ioctl_search_header);
2082		return -EOVERFLOW;
2083	}
2084
2085	path = btrfs_alloc_path();
2086	if (!path)
2087		return -ENOMEM;
2088
2089	if (sk->tree_id == 0) {
2090		/* search the root of the inode that was passed */
2091		root = BTRFS_I(inode)->root;
2092	} else {
2093		key.objectid = sk->tree_id;
2094		key.type = BTRFS_ROOT_ITEM_KEY;
2095		key.offset = (u64)-1;
2096		root = btrfs_read_fs_root_no_name(info, &key);
2097		if (IS_ERR(root)) {
 
 
2098			btrfs_free_path(path);
2099			return -ENOENT;
2100		}
2101	}
2102
2103	key.objectid = sk->min_objectid;
2104	key.type = sk->min_type;
2105	key.offset = sk->min_offset;
2106
2107	while (1) {
2108		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
 
 
 
 
 
 
 
2109		if (ret != 0) {
2110			if (ret > 0)
2111				ret = 0;
2112			goto err;
2113		}
2114		ret = copy_to_sk(root, path, &key, sk, buf_size, ubuf,
2115				 &sk_offset, &num_found);
2116		btrfs_release_path(path);
2117		if (ret)
2118			break;
2119
2120	}
2121	if (ret > 0)
2122		ret = 0;
2123err:
2124	sk->nr_items = num_found;
2125	btrfs_free_path(path);
2126	return ret;
2127}
2128
2129static noinline int btrfs_ioctl_tree_search(struct file *file,
2130					   void __user *argp)
2131{
2132	struct btrfs_ioctl_search_args __user *uargs;
2133	struct btrfs_ioctl_search_key sk;
2134	struct inode *inode;
2135	int ret;
2136	size_t buf_size;
2137
2138	if (!capable(CAP_SYS_ADMIN))
2139		return -EPERM;
2140
2141	uargs = (struct btrfs_ioctl_search_args __user *)argp;
 
 
2142
2143	if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2144		return -EFAULT;
2145
2146	buf_size = sizeof(uargs->buf);
2147
2148	inode = file_inode(file);
2149	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2150
2151	/*
2152	 * In the origin implementation an overflow is handled by returning a
2153	 * search header with a len of zero, so reset ret.
2154	 */
2155	if (ret == -EOVERFLOW)
2156		ret = 0;
2157
2158	if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2159		ret = -EFAULT;
2160	return ret;
2161}
2162
2163static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2164					       void __user *argp)
2165{
2166	struct btrfs_ioctl_search_args_v2 __user *uarg;
2167	struct btrfs_ioctl_search_args_v2 args;
2168	struct inode *inode;
2169	int ret;
2170	size_t buf_size;
2171	const size_t buf_limit = SZ_16M;
2172
2173	if (!capable(CAP_SYS_ADMIN))
2174		return -EPERM;
2175
2176	/* copy search header and buffer size */
2177	uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2178	if (copy_from_user(&args, uarg, sizeof(args)))
2179		return -EFAULT;
2180
2181	buf_size = args.buf_size;
2182
2183	if (buf_size < sizeof(struct btrfs_ioctl_search_header))
2184		return -EOVERFLOW;
2185
2186	/* limit result size to 16MB */
2187	if (buf_size > buf_limit)
2188		buf_size = buf_limit;
2189
2190	inode = file_inode(file);
2191	ret = search_ioctl(inode, &args.key, &buf_size,
2192			   (char *)(&uarg->buf[0]));
2193	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2194		ret = -EFAULT;
2195	else if (ret == -EOVERFLOW &&
2196		copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2197		ret = -EFAULT;
2198
2199	return ret;
2200}
2201
2202/*
2203 * Search INODE_REFs to identify path name of 'dirid' directory
2204 * in a 'tree_id' tree. and sets path name to 'name'.
2205 */
2206static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2207				u64 tree_id, u64 dirid, char *name)
2208{
2209	struct btrfs_root *root;
2210	struct btrfs_key key;
2211	char *ptr;
2212	int ret = -1;
2213	int slot;
2214	int len;
2215	int total_len = 0;
2216	struct btrfs_inode_ref *iref;
2217	struct extent_buffer *l;
2218	struct btrfs_path *path;
2219
2220	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2221		name[0]='\0';
2222		return 0;
2223	}
2224
2225	path = btrfs_alloc_path();
2226	if (!path)
2227		return -ENOMEM;
2228
2229	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2230
2231	key.objectid = tree_id;
2232	key.type = BTRFS_ROOT_ITEM_KEY;
2233	key.offset = (u64)-1;
2234	root = btrfs_read_fs_root_no_name(info, &key);
2235	if (IS_ERR(root)) {
2236		btrfs_err(info, "could not find root %llu", tree_id);
2237		ret = -ENOENT;
2238		goto out;
2239	}
2240
2241	key.objectid = dirid;
2242	key.type = BTRFS_INODE_REF_KEY;
2243	key.offset = (u64)-1;
2244
2245	while (1) {
2246		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2247		if (ret < 0)
2248			goto out;
2249		else if (ret > 0) {
2250			ret = btrfs_previous_item(root, path, dirid,
2251						  BTRFS_INODE_REF_KEY);
2252			if (ret < 0)
2253				goto out;
2254			else if (ret > 0) {
2255				ret = -ENOENT;
2256				goto out;
2257			}
2258		}
2259
2260		l = path->nodes[0];
2261		slot = path->slots[0];
 
 
2262		btrfs_item_key_to_cpu(l, &key, slot);
2263
 
 
 
 
 
 
2264		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2265		len = btrfs_inode_ref_name_len(l, iref);
2266		ptr -= len + 1;
2267		total_len += len + 1;
2268		if (ptr < name) {
2269			ret = -ENAMETOOLONG;
2270			goto out;
2271		}
2272
2273		*(ptr + len) = '/';
2274		read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2275
2276		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2277			break;
2278
2279		btrfs_release_path(path);
2280		key.objectid = key.offset;
2281		key.offset = (u64)-1;
2282		dirid = key.objectid;
2283	}
 
 
2284	memmove(name, ptr, total_len);
2285	name[total_len] = '\0';
2286	ret = 0;
2287out:
2288	btrfs_free_path(path);
2289	return ret;
2290}
2291
2292static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2293					   void __user *argp)
2294{
2295	 struct btrfs_ioctl_ino_lookup_args *args;
2296	 struct inode *inode;
2297	int ret = 0;
 
 
 
2298
2299	args = memdup_user(argp, sizeof(*args));
2300	if (IS_ERR(args))
2301		return PTR_ERR(args);
2302
2303	inode = file_inode(file);
2304
2305	/*
2306	 * Unprivileged query to obtain the containing subvolume root id. The
2307	 * path is reset so it's consistent with btrfs_search_path_in_tree.
2308	 */
2309	if (args->treeid == 0)
2310		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2311
2312	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2313		args->name[0] = 0;
2314		goto out;
2315	}
2316
2317	if (!capable(CAP_SYS_ADMIN)) {
2318		ret = -EPERM;
2319		goto out;
2320	}
2321
2322	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2323					args->treeid, args->objectid,
2324					args->name);
2325
2326out:
2327	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2328		ret = -EFAULT;
2329
2330	kfree(args);
2331	return ret;
2332}
2333
2334static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2335					     void __user *arg)
2336{
2337	struct dentry *parent = file->f_path.dentry;
2338	struct dentry *dentry;
2339	struct inode *dir = d_inode(parent);
2340	struct inode *inode;
2341	struct btrfs_root *root = BTRFS_I(dir)->root;
2342	struct btrfs_root *dest = NULL;
2343	struct btrfs_ioctl_vol_args *vol_args;
2344	struct btrfs_trans_handle *trans;
2345	struct btrfs_block_rsv block_rsv;
2346	u64 root_flags;
2347	u64 qgroup_reserved;
2348	int namelen;
2349	int ret;
2350	int err = 0;
2351
2352	vol_args = memdup_user(arg, sizeof(*vol_args));
2353	if (IS_ERR(vol_args))
2354		return PTR_ERR(vol_args);
2355
2356	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2357	namelen = strlen(vol_args->name);
2358	if (strchr(vol_args->name, '/') ||
2359	    strncmp(vol_args->name, "..", namelen) == 0) {
2360		err = -EINVAL;
2361		goto out;
2362	}
2363
2364	err = mnt_want_write_file(file);
2365	if (err)
2366		goto out;
2367
2368
2369	err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
2370	if (err == -EINTR)
2371		goto out_drop_write;
2372	dentry = lookup_one_len(vol_args->name, parent, namelen);
2373	if (IS_ERR(dentry)) {
2374		err = PTR_ERR(dentry);
2375		goto out_unlock_dir;
2376	}
2377
2378	if (d_really_is_negative(dentry)) {
2379		err = -ENOENT;
2380		goto out_dput;
2381	}
2382
2383	inode = d_inode(dentry);
2384	dest = BTRFS_I(inode)->root;
2385	if (!capable(CAP_SYS_ADMIN)) {
2386		/*
2387		 * Regular user.  Only allow this with a special mount
2388		 * option, when the user has write+exec access to the
2389		 * subvol root, and when rmdir(2) would have been
2390		 * allowed.
2391		 *
2392		 * Note that this is _not_ check that the subvol is
2393		 * empty or doesn't contain data that we wouldn't
2394		 * otherwise be able to delete.
2395		 *
2396		 * Users who want to delete empty subvols should try
2397		 * rmdir(2).
2398		 */
2399		err = -EPERM;
2400		if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2401			goto out_dput;
2402
2403		/*
2404		 * Do not allow deletion if the parent dir is the same
2405		 * as the dir to be deleted.  That means the ioctl
2406		 * must be called on the dentry referencing the root
2407		 * of the subvol, not a random directory contained
2408		 * within it.
2409		 */
2410		err = -EINVAL;
2411		if (root == dest)
2412			goto out_dput;
2413
2414		err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2415		if (err)
2416			goto out_dput;
 
 
 
 
 
2417	}
2418
2419	/* check if subvolume may be deleted by a user */
2420	err = btrfs_may_delete(dir, dentry, 1);
2421	if (err)
2422		goto out_dput;
2423
2424	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2425		err = -EINVAL;
2426		goto out_dput;
2427	}
2428
2429	inode_lock(inode);
2430
2431	/*
2432	 * Don't allow to delete a subvolume with send in progress. This is
2433	 * inside the i_mutex so the error handling that has to drop the bit
2434	 * again is not run concurrently.
2435	 */
2436	spin_lock(&dest->root_item_lock);
2437	root_flags = btrfs_root_flags(&dest->root_item);
2438	if (dest->send_in_progress == 0) {
2439		btrfs_set_root_flags(&dest->root_item,
2440				root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2441		spin_unlock(&dest->root_item_lock);
2442	} else {
2443		spin_unlock(&dest->root_item_lock);
2444		btrfs_warn(root->fs_info,
2445			"Attempt to delete subvolume %llu during send",
2446			dest->root_key.objectid);
2447		err = -EPERM;
2448		goto out_unlock_inode;
2449	}
2450
2451	down_write(&root->fs_info->subvol_sem);
2452
2453	err = may_destroy_subvol(dest);
2454	if (err)
2455		goto out_up_write;
2456
2457	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2458	/*
2459	 * One for dir inode, two for dir entries, two for root
2460	 * ref/backref.
2461	 */
2462	err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2463					       5, &qgroup_reserved, true);
2464	if (err)
2465		goto out_up_write;
2466
2467	trans = btrfs_start_transaction(root, 0);
2468	if (IS_ERR(trans)) {
2469		err = PTR_ERR(trans);
2470		goto out_release;
2471	}
2472	trans->block_rsv = &block_rsv;
2473	trans->bytes_reserved = block_rsv.size;
2474
2475	btrfs_record_snapshot_destroy(trans, dir);
2476
2477	ret = btrfs_unlink_subvol(trans, root, dir,
2478				dest->root_key.objectid,
2479				dentry->d_name.name,
2480				dentry->d_name.len);
2481	if (ret) {
2482		err = ret;
2483		btrfs_abort_transaction(trans, root, ret);
2484		goto out_end_trans;
2485	}
2486
2487	btrfs_record_root_in_trans(trans, dest);
2488
2489	memset(&dest->root_item.drop_progress, 0,
2490		sizeof(dest->root_item.drop_progress));
2491	dest->root_item.drop_level = 0;
2492	btrfs_set_root_refs(&dest->root_item, 0);
2493
2494	if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2495		ret = btrfs_insert_orphan_item(trans,
2496					root->fs_info->tree_root,
2497					dest->root_key.objectid);
2498		if (ret) {
2499			btrfs_abort_transaction(trans, root, ret);
2500			err = ret;
2501			goto out_end_trans;
2502		}
2503	}
2504
2505	ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2506				  dest->root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
2507				  dest->root_key.objectid);
2508	if (ret && ret != -ENOENT) {
2509		btrfs_abort_transaction(trans, root, ret);
2510		err = ret;
2511		goto out_end_trans;
2512	}
2513	if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2514		ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2515					  dest->root_item.received_uuid,
2516					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2517					  dest->root_key.objectid);
2518		if (ret && ret != -ENOENT) {
2519			btrfs_abort_transaction(trans, root, ret);
2520			err = ret;
2521			goto out_end_trans;
2522		}
2523	}
2524
2525out_end_trans:
2526	trans->block_rsv = NULL;
2527	trans->bytes_reserved = 0;
2528	ret = btrfs_end_transaction(trans, root);
2529	if (ret && !err)
2530		err = ret;
2531	inode->i_flags |= S_DEAD;
2532out_release:
2533	btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
2534out_up_write:
2535	up_write(&root->fs_info->subvol_sem);
2536	if (err) {
2537		spin_lock(&dest->root_item_lock);
2538		root_flags = btrfs_root_flags(&dest->root_item);
2539		btrfs_set_root_flags(&dest->root_item,
2540				root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2541		spin_unlock(&dest->root_item_lock);
2542	}
2543out_unlock_inode:
2544	inode_unlock(inode);
2545	if (!err) {
2546		d_invalidate(dentry);
2547		btrfs_invalidate_inodes(dest);
2548		d_delete(dentry);
2549		ASSERT(dest->send_in_progress == 0);
2550
2551		/* the last ref */
2552		if (dest->ino_cache_inode) {
2553			iput(dest->ino_cache_inode);
2554			dest->ino_cache_inode = NULL;
2555		}
2556	}
2557out_dput:
2558	dput(dentry);
2559out_unlock_dir:
2560	inode_unlock(dir);
2561out_drop_write:
2562	mnt_drop_write_file(file);
2563out:
2564	kfree(vol_args);
2565	return err;
2566}
2567
2568static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2569{
2570	struct inode *inode = file_inode(file);
2571	struct btrfs_root *root = BTRFS_I(inode)->root;
2572	struct btrfs_ioctl_defrag_range_args *range;
2573	int ret;
2574
2575	ret = mnt_want_write_file(file);
 
 
 
2576	if (ret)
2577		return ret;
2578
2579	if (btrfs_root_readonly(root)) {
2580		ret = -EROFS;
2581		goto out;
2582	}
2583
2584	switch (inode->i_mode & S_IFMT) {
2585	case S_IFDIR:
2586		if (!capable(CAP_SYS_ADMIN)) {
2587			ret = -EPERM;
2588			goto out;
2589		}
2590		ret = btrfs_defrag_root(root);
2591		if (ret)
2592			goto out;
2593		ret = btrfs_defrag_root(root->fs_info->extent_root);
2594		break;
2595	case S_IFREG:
2596		if (!(file->f_mode & FMODE_WRITE)) {
2597			ret = -EINVAL;
2598			goto out;
2599		}
2600
2601		range = kzalloc(sizeof(*range), GFP_KERNEL);
2602		if (!range) {
2603			ret = -ENOMEM;
2604			goto out;
2605		}
2606
2607		if (argp) {
2608			if (copy_from_user(range, argp,
2609					   sizeof(*range))) {
2610				ret = -EFAULT;
2611				kfree(range);
2612				goto out;
2613			}
2614			/* compression requires us to start the IO */
2615			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2616				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2617				range->extent_thresh = (u32)-1;
2618			}
2619		} else {
2620			/* the rest are all set to zero by kzalloc */
2621			range->len = (u64)-1;
2622		}
2623		ret = btrfs_defrag_file(file_inode(file), file,
2624					range, 0, 0);
2625		if (ret > 0)
2626			ret = 0;
2627		kfree(range);
2628		break;
2629	default:
2630		ret = -EINVAL;
2631	}
2632out:
2633	mnt_drop_write_file(file);
2634	return ret;
2635}
2636
2637static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2638{
2639	struct btrfs_ioctl_vol_args *vol_args;
2640	int ret;
2641
2642	if (!capable(CAP_SYS_ADMIN))
2643		return -EPERM;
2644
2645	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2646			1)) {
2647		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2648	}
2649
2650	mutex_lock(&root->fs_info->volume_mutex);
2651	vol_args = memdup_user(arg, sizeof(*vol_args));
2652	if (IS_ERR(vol_args)) {
2653		ret = PTR_ERR(vol_args);
2654		goto out;
2655	}
2656
2657	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2658	ret = btrfs_init_new_device(root, vol_args->name);
2659
2660	if (!ret)
2661		btrfs_info(root->fs_info, "disk added %s",vol_args->name);
2662
2663	kfree(vol_args);
2664out:
2665	mutex_unlock(&root->fs_info->volume_mutex);
2666	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2667	return ret;
2668}
2669
2670static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2671{
2672	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
2673	struct btrfs_ioctl_vol_args *vol_args;
2674	int ret;
2675
2676	if (!capable(CAP_SYS_ADMIN))
2677		return -EPERM;
2678
2679	ret = mnt_want_write_file(file);
2680	if (ret)
2681		return ret;
2682
2683	vol_args = memdup_user(arg, sizeof(*vol_args));
2684	if (IS_ERR(vol_args)) {
2685		ret = PTR_ERR(vol_args);
2686		goto err_drop;
2687	}
2688
2689	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2690
2691	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2692			1)) {
2693		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2694		goto out;
2695	}
2696
2697	mutex_lock(&root->fs_info->volume_mutex);
2698	ret = btrfs_rm_device(root, vol_args->name);
2699	mutex_unlock(&root->fs_info->volume_mutex);
2700	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2701
2702	if (!ret)
2703		btrfs_info(root->fs_info, "disk deleted %s",vol_args->name);
2704
2705out:
2706	kfree(vol_args);
2707err_drop:
2708	mnt_drop_write_file(file);
2709	return ret;
2710}
2711
2712static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2713{
2714	struct btrfs_ioctl_fs_info_args *fi_args;
2715	struct btrfs_device *device;
 
2716	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2717	int ret = 0;
2718
 
 
 
2719	fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2720	if (!fi_args)
2721		return -ENOMEM;
2722
2723	mutex_lock(&fs_devices->device_list_mutex);
2724	fi_args->num_devices = fs_devices->num_devices;
2725	memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2726
2727	list_for_each_entry(device, &fs_devices->devices, dev_list) {
 
2728		if (device->devid > fi_args->max_id)
2729			fi_args->max_id = device->devid;
2730	}
2731	mutex_unlock(&fs_devices->device_list_mutex);
2732
2733	fi_args->nodesize = root->fs_info->super_copy->nodesize;
2734	fi_args->sectorsize = root->fs_info->super_copy->sectorsize;
2735	fi_args->clone_alignment = root->fs_info->super_copy->sectorsize;
2736
2737	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2738		ret = -EFAULT;
2739
2740	kfree(fi_args);
2741	return ret;
2742}
2743
2744static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2745{
2746	struct btrfs_ioctl_dev_info_args *di_args;
2747	struct btrfs_device *dev;
2748	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2749	int ret = 0;
2750	char *s_uuid = NULL;
 
 
 
 
2751
2752	di_args = memdup_user(arg, sizeof(*di_args));
2753	if (IS_ERR(di_args))
2754		return PTR_ERR(di_args);
2755
2756	if (!btrfs_is_empty_uuid(di_args->uuid))
2757		s_uuid = di_args->uuid;
2758
2759	mutex_lock(&fs_devices->device_list_mutex);
2760	dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
 
2761
2762	if (!dev) {
2763		ret = -ENODEV;
2764		goto out;
2765	}
2766
2767	di_args->devid = dev->devid;
2768	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2769	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2770	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2771	if (dev->name) {
2772		struct rcu_string *name;
2773
2774		rcu_read_lock();
2775		name = rcu_dereference(dev->name);
2776		strncpy(di_args->path, name->str, sizeof(di_args->path));
2777		rcu_read_unlock();
2778		di_args->path[sizeof(di_args->path) - 1] = 0;
2779	} else {
2780		di_args->path[0] = '\0';
2781	}
2782
2783out:
2784	mutex_unlock(&fs_devices->device_list_mutex);
2785	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2786		ret = -EFAULT;
2787
2788	kfree(di_args);
2789	return ret;
2790}
2791
2792static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
 
2793{
2794	struct page *page;
2795
2796	page = grab_cache_page(inode->i_mapping, index);
2797	if (!page)
2798		return ERR_PTR(-ENOMEM);
2799
2800	if (!PageUptodate(page)) {
2801		int ret;
2802
2803		ret = btrfs_readpage(NULL, page);
2804		if (ret)
2805			return ERR_PTR(ret);
2806		lock_page(page);
2807		if (!PageUptodate(page)) {
2808			unlock_page(page);
2809			put_page(page);
2810			return ERR_PTR(-EIO);
2811		}
2812		if (page->mapping != inode->i_mapping) {
2813			unlock_page(page);
2814			put_page(page);
2815			return ERR_PTR(-EAGAIN);
2816		}
2817	}
2818
2819	return page;
2820}
2821
2822static int gather_extent_pages(struct inode *inode, struct page **pages,
2823			       int num_pages, u64 off)
2824{
2825	int i;
2826	pgoff_t index = off >> PAGE_SHIFT;
2827
2828	for (i = 0; i < num_pages; i++) {
2829again:
2830		pages[i] = extent_same_get_page(inode, index + i);
2831		if (IS_ERR(pages[i])) {
2832			int err = PTR_ERR(pages[i]);
2833
2834			if (err == -EAGAIN)
2835				goto again;
2836			pages[i] = NULL;
2837			return err;
2838		}
2839	}
2840	return 0;
2841}
2842
2843static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2844			     bool retry_range_locking)
2845{
2846	/*
2847	 * Do any pending delalloc/csum calculations on inode, one way or
2848	 * another, and lock file content.
2849	 * The locking order is:
2850	 *
2851	 *   1) pages
2852	 *   2) range in the inode's io tree
 
2853	 */
2854	while (1) {
2855		struct btrfs_ordered_extent *ordered;
2856		lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2857		ordered = btrfs_lookup_first_ordered_extent(inode,
2858							    off + len - 1);
2859		if ((!ordered ||
2860		     ordered->file_offset + ordered->len <= off ||
2861		     ordered->file_offset >= off + len) &&
2862		    !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2863				    off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2864			if (ordered)
2865				btrfs_put_ordered_extent(ordered);
2866			break;
2867		}
2868		unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2869		if (ordered)
2870			btrfs_put_ordered_extent(ordered);
2871		if (!retry_range_locking)
2872			return -EAGAIN;
2873		btrfs_wait_ordered_range(inode, off, len);
2874	}
2875	return 0;
2876}
2877
2878static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2879{
2880	inode_unlock(inode1);
2881	inode_unlock(inode2);
2882}
2883
2884static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2885{
2886	if (inode1 < inode2)
2887		swap(inode1, inode2);
2888
2889	inode_lock_nested(inode1, I_MUTEX_PARENT);
2890	inode_lock_nested(inode2, I_MUTEX_CHILD);
2891}
2892
2893static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2894				      struct inode *inode2, u64 loff2, u64 len)
2895{
2896	unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2897	unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2898}
2899
2900static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2901				    struct inode *inode2, u64 loff2, u64 len,
2902				    bool retry_range_locking)
2903{
2904	int ret;
2905
2906	if (inode1 < inode2) {
2907		swap(inode1, inode2);
2908		swap(loff1, loff2);
2909	}
2910	ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2911	if (ret)
2912		return ret;
2913	ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2914	if (ret)
2915		unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2916			      loff1 + len - 1);
2917	return ret;
2918}
2919
2920struct cmp_pages {
2921	int		num_pages;
2922	struct page	**src_pages;
2923	struct page	**dst_pages;
2924};
2925
2926static void btrfs_cmp_data_free(struct cmp_pages *cmp)
2927{
2928	int i;
2929	struct page *pg;
2930
2931	for (i = 0; i < cmp->num_pages; i++) {
2932		pg = cmp->src_pages[i];
2933		if (pg) {
2934			unlock_page(pg);
2935			put_page(pg);
2936		}
2937		pg = cmp->dst_pages[i];
2938		if (pg) {
2939			unlock_page(pg);
2940			put_page(pg);
2941		}
2942	}
2943	kfree(cmp->src_pages);
2944	kfree(cmp->dst_pages);
2945}
2946
2947static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
2948				  struct inode *dst, u64 dst_loff,
2949				  u64 len, struct cmp_pages *cmp)
2950{
2951	int ret;
2952	int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
2953	struct page **src_pgarr, **dst_pgarr;
2954
2955	/*
2956	 * We must gather up all the pages before we initiate our
2957	 * extent locking. We use an array for the page pointers. Size
2958	 * of the array is bounded by len, which is in turn bounded by
2959	 * BTRFS_MAX_DEDUPE_LEN.
2960	 */
2961	src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
2962	dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
2963	if (!src_pgarr || !dst_pgarr) {
2964		kfree(src_pgarr);
2965		kfree(dst_pgarr);
2966		return -ENOMEM;
2967	}
2968	cmp->num_pages = num_pages;
2969	cmp->src_pages = src_pgarr;
2970	cmp->dst_pages = dst_pgarr;
2971
2972	ret = gather_extent_pages(src, cmp->src_pages, cmp->num_pages, loff);
2973	if (ret)
2974		goto out;
2975
2976	ret = gather_extent_pages(dst, cmp->dst_pages, cmp->num_pages, dst_loff);
 
 
 
2977
2978out:
2979	if (ret)
2980		btrfs_cmp_data_free(cmp);
2981	return 0;
2982}
2983
2984static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
2985			  u64 dst_loff, u64 len, struct cmp_pages *cmp)
2986{
2987	int ret = 0;
2988	int i;
2989	struct page *src_page, *dst_page;
2990	unsigned int cmp_len = PAGE_SIZE;
2991	void *addr, *dst_addr;
2992
2993	i = 0;
2994	while (len) {
2995		if (len < PAGE_SIZE)
2996			cmp_len = len;
2997
2998		BUG_ON(i >= cmp->num_pages);
2999
3000		src_page = cmp->src_pages[i];
3001		dst_page = cmp->dst_pages[i];
3002		ASSERT(PageLocked(src_page));
3003		ASSERT(PageLocked(dst_page));
3004
3005		addr = kmap_atomic(src_page);
3006		dst_addr = kmap_atomic(dst_page);
3007
3008		flush_dcache_page(src_page);
3009		flush_dcache_page(dst_page);
3010
3011		if (memcmp(addr, dst_addr, cmp_len))
3012			ret = -EBADE;
3013
3014		kunmap_atomic(addr);
3015		kunmap_atomic(dst_addr);
3016
3017		if (ret)
3018			break;
3019
3020		len -= cmp_len;
3021		i++;
3022	}
 
3023
3024	return ret;
3025}
3026
3027static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3028				     u64 olen)
3029{
3030	u64 len = *plen;
3031	u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3032
3033	if (off + olen > inode->i_size || off + olen < off)
3034		return -EINVAL;
3035
3036	/* if we extend to eof, continue to block boundary */
3037	if (off + len == inode->i_size)
3038		*plen = len = ALIGN(inode->i_size, bs) - off;
3039
3040	/* Check that we are block aligned - btrfs_clone() requires this */
3041	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3042		return -EINVAL;
3043
3044	return 0;
3045}
3046
3047static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3048			     struct inode *dst, u64 dst_loff)
3049{
3050	int ret;
3051	u64 len = olen;
3052	struct cmp_pages cmp;
3053	int same_inode = 0;
3054	u64 same_lock_start = 0;
3055	u64 same_lock_len = 0;
3056
3057	if (src == dst)
3058		same_inode = 1;
3059
3060	if (len == 0)
3061		return 0;
3062
3063	if (same_inode) {
3064		inode_lock(src);
3065
3066		ret = extent_same_check_offsets(src, loff, &len, olen);
3067		if (ret)
3068			goto out_unlock;
3069		ret = extent_same_check_offsets(src, dst_loff, &len, olen);
3070		if (ret)
3071			goto out_unlock;
3072
3073		/*
3074		 * Single inode case wants the same checks, except we
3075		 * don't want our length pushed out past i_size as
3076		 * comparing that data range makes no sense.
3077		 *
3078		 * extent_same_check_offsets() will do this for an
3079		 * unaligned length at i_size, so catch it here and
3080		 * reject the request.
3081		 *
3082		 * This effectively means we require aligned extents
3083		 * for the single-inode case, whereas the other cases
3084		 * allow an unaligned length so long as it ends at
3085		 * i_size.
3086		 */
3087		if (len != olen) {
3088			ret = -EINVAL;
3089			goto out_unlock;
3090		}
3091
3092		/* Check for overlapping ranges */
3093		if (dst_loff + len > loff && dst_loff < loff + len) {
3094			ret = -EINVAL;
3095			goto out_unlock;
3096		}
3097
3098		same_lock_start = min_t(u64, loff, dst_loff);
3099		same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3100	} else {
3101		btrfs_double_inode_lock(src, dst);
3102
3103		ret = extent_same_check_offsets(src, loff, &len, olen);
3104		if (ret)
3105			goto out_unlock;
3106
3107		ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3108		if (ret)
3109			goto out_unlock;
3110	}
3111
3112	/* don't make the dst file partly checksummed */
3113	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3114	    (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3115		ret = -EINVAL;
3116		goto out_unlock;
3117	}
 
 
 
 
3118
3119again:
3120	ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3121	if (ret)
3122		goto out_unlock;
3123
3124	if (same_inode)
3125		ret = lock_extent_range(src, same_lock_start, same_lock_len,
3126					false);
3127	else
3128		ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3129					       false);
3130	/*
3131	 * If one of the inodes has dirty pages in the respective range or
3132	 * ordered extents, we need to flush dellaloc and wait for all ordered
3133	 * extents in the range. We must unlock the pages and the ranges in the
3134	 * io trees to avoid deadlocks when flushing delalloc (requires locking
3135	 * pages) and when waiting for ordered extents to complete (they require
3136	 * range locking).
3137	 */
3138	if (ret == -EAGAIN) {
3139		/*
3140		 * Ranges in the io trees already unlocked. Now unlock all
3141		 * pages before waiting for all IO to complete.
3142		 */
3143		btrfs_cmp_data_free(&cmp);
3144		if (same_inode) {
3145			btrfs_wait_ordered_range(src, same_lock_start,
3146						 same_lock_len);
3147		} else {
3148			btrfs_wait_ordered_range(src, loff, len);
3149			btrfs_wait_ordered_range(dst, dst_loff, len);
3150		}
3151		goto again;
3152	}
3153	ASSERT(ret == 0);
3154	if (WARN_ON(ret)) {
3155		/* ranges in the io trees already unlocked */
3156		btrfs_cmp_data_free(&cmp);
3157		return ret;
3158	}
3159
3160	/* pass original length for comparison so we stay within i_size */
3161	ret = btrfs_cmp_data(src, loff, dst, dst_loff, olen, &cmp);
3162	if (ret == 0)
3163		ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3164
3165	if (same_inode)
3166		unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3167			      same_lock_start + same_lock_len - 1);
3168	else
3169		btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3170
3171	btrfs_cmp_data_free(&cmp);
3172out_unlock:
3173	if (same_inode)
3174		inode_unlock(src);
3175	else
3176		btrfs_double_inode_unlock(src, dst);
3177
3178	return ret;
3179}
3180
3181#define BTRFS_MAX_DEDUPE_LEN	SZ_16M
3182
3183ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3184				struct file *dst_file, u64 dst_loff)
3185{
3186	struct inode *src = file_inode(src_file);
3187	struct inode *dst = file_inode(dst_file);
3188	u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3189	ssize_t res;
3190
3191	if (olen > BTRFS_MAX_DEDUPE_LEN)
3192		olen = BTRFS_MAX_DEDUPE_LEN;
3193
3194	if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3195		/*
3196		 * Btrfs does not support blocksize < page_size. As a
3197		 * result, btrfs_cmp_data() won't correctly handle
3198		 * this situation without an update.
3199		 */
3200		return -EINVAL;
3201	}
3202
3203	res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3204	if (res)
3205		return res;
3206	return olen;
3207}
3208
3209static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3210				     struct inode *inode,
3211				     u64 endoff,
3212				     const u64 destoff,
3213				     const u64 olen,
3214				     int no_time_update)
3215{
3216	struct btrfs_root *root = BTRFS_I(inode)->root;
3217	int ret;
3218
3219	inode_inc_iversion(inode);
3220	if (!no_time_update)
3221		inode->i_mtime = inode->i_ctime = current_fs_time(inode->i_sb);
3222	/*
3223	 * We round up to the block size at eof when determining which
3224	 * extents to clone above, but shouldn't round up the file size.
3225	 */
3226	if (endoff > destoff + olen)
3227		endoff = destoff + olen;
3228	if (endoff > inode->i_size)
3229		btrfs_i_size_write(inode, endoff);
3230
3231	ret = btrfs_update_inode(trans, root, inode);
3232	if (ret) {
3233		btrfs_abort_transaction(trans, root, ret);
3234		btrfs_end_transaction(trans, root);
3235		goto out;
3236	}
3237	ret = btrfs_end_transaction(trans, root);
3238out:
3239	return ret;
3240}
3241
3242static void clone_update_extent_map(struct inode *inode,
3243				    const struct btrfs_trans_handle *trans,
3244				    const struct btrfs_path *path,
3245				    const u64 hole_offset,
3246				    const u64 hole_len)
3247{
3248	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3249	struct extent_map *em;
3250	int ret;
3251
3252	em = alloc_extent_map();
3253	if (!em) {
3254		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3255			&BTRFS_I(inode)->runtime_flags);
3256		return;
3257	}
3258
3259	if (path) {
3260		struct btrfs_file_extent_item *fi;
3261
3262		fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3263				    struct btrfs_file_extent_item);
3264		btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3265		em->generation = -1;
3266		if (btrfs_file_extent_type(path->nodes[0], fi) ==
3267		    BTRFS_FILE_EXTENT_INLINE)
3268			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3269				&BTRFS_I(inode)->runtime_flags);
3270	} else {
3271		em->start = hole_offset;
3272		em->len = hole_len;
3273		em->ram_bytes = em->len;
3274		em->orig_start = hole_offset;
3275		em->block_start = EXTENT_MAP_HOLE;
3276		em->block_len = 0;
3277		em->orig_block_len = 0;
3278		em->compress_type = BTRFS_COMPRESS_NONE;
3279		em->generation = trans->transid;
3280	}
3281
 
 
3282	while (1) {
3283		write_lock(&em_tree->lock);
3284		ret = add_extent_mapping(em_tree, em, 1);
3285		write_unlock(&em_tree->lock);
3286		if (ret != -EEXIST) {
3287			free_extent_map(em);
 
3288			break;
3289		}
3290		btrfs_drop_extent_cache(inode, em->start,
3291					em->start + em->len - 1, 0);
3292	}
3293
3294	if (ret)
3295		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3296			&BTRFS_I(inode)->runtime_flags);
3297}
3298
3299/*
3300 * Make sure we do not end up inserting an inline extent into a file that has
3301 * already other (non-inline) extents. If a file has an inline extent it can
3302 * not have any other extents and the (single) inline extent must start at the
3303 * file offset 0. Failing to respect these rules will lead to file corruption,
3304 * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3305 *
3306 * We can have extents that have been already written to disk or we can have
3307 * dirty ranges still in delalloc, in which case the extent maps and items are
3308 * created only when we run delalloc, and the delalloc ranges might fall outside
3309 * the range we are currently locking in the inode's io tree. So we check the
3310 * inode's i_size because of that (i_size updates are done while holding the
3311 * i_mutex, which we are holding here).
3312 * We also check to see if the inode has a size not greater than "datal" but has
3313 * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3314 * protected against such concurrent fallocate calls by the i_mutex).
3315 *
3316 * If the file has no extents but a size greater than datal, do not allow the
3317 * copy because we would need turn the inline extent into a non-inline one (even
3318 * with NO_HOLES enabled). If we find our destination inode only has one inline
3319 * extent, just overwrite it with the source inline extent if its size is less
3320 * than the source extent's size, or we could copy the source inline extent's
3321 * data into the destination inode's inline extent if the later is greater then
3322 * the former.
3323 */
3324static int clone_copy_inline_extent(struct inode *src,
3325				    struct inode *dst,
3326				    struct btrfs_trans_handle *trans,
3327				    struct btrfs_path *path,
3328				    struct btrfs_key *new_key,
3329				    const u64 drop_start,
3330				    const u64 datal,
3331				    const u64 skip,
3332				    const u64 size,
3333				    char *inline_data)
3334{
3335	struct btrfs_root *root = BTRFS_I(dst)->root;
3336	const u64 aligned_end = ALIGN(new_key->offset + datal,
3337				      root->sectorsize);
3338	int ret;
3339	struct btrfs_key key;
3340
3341	if (new_key->offset > 0)
3342		return -EOPNOTSUPP;
3343
3344	key.objectid = btrfs_ino(dst);
3345	key.type = BTRFS_EXTENT_DATA_KEY;
3346	key.offset = 0;
3347	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3348	if (ret < 0) {
3349		return ret;
3350	} else if (ret > 0) {
3351		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3352			ret = btrfs_next_leaf(root, path);
3353			if (ret < 0)
3354				return ret;
3355			else if (ret > 0)
3356				goto copy_inline_extent;
3357		}
3358		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3359		if (key.objectid == btrfs_ino(dst) &&
3360		    key.type == BTRFS_EXTENT_DATA_KEY) {
3361			ASSERT(key.offset > 0);
3362			return -EOPNOTSUPP;
3363		}
3364	} else if (i_size_read(dst) <= datal) {
3365		struct btrfs_file_extent_item *ei;
3366		u64 ext_len;
3367
3368		/*
3369		 * If the file size is <= datal, make sure there are no other
3370		 * extents following (can happen do to an fallocate call with
3371		 * the flag FALLOC_FL_KEEP_SIZE).
3372		 */
3373		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3374				    struct btrfs_file_extent_item);
3375		/*
3376		 * If it's an inline extent, it can not have other extents
3377		 * following it.
3378		 */
3379		if (btrfs_file_extent_type(path->nodes[0], ei) ==
3380		    BTRFS_FILE_EXTENT_INLINE)
3381			goto copy_inline_extent;
3382
3383		ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3384		if (ext_len > aligned_end)
3385			return -EOPNOTSUPP;
3386
3387		ret = btrfs_next_item(root, path);
3388		if (ret < 0) {
3389			return ret;
3390		} else if (ret == 0) {
3391			btrfs_item_key_to_cpu(path->nodes[0], &key,
3392					      path->slots[0]);
3393			if (key.objectid == btrfs_ino(dst) &&
3394			    key.type == BTRFS_EXTENT_DATA_KEY)
3395				return -EOPNOTSUPP;
3396		}
3397	}
3398
3399copy_inline_extent:
3400	/*
3401	 * We have no extent items, or we have an extent at offset 0 which may
3402	 * or may not be inlined. All these cases are dealt the same way.
3403	 */
3404	if (i_size_read(dst) > datal) {
3405		/*
3406		 * If the destination inode has an inline extent...
3407		 * This would require copying the data from the source inline
3408		 * extent into the beginning of the destination's inline extent.
3409		 * But this is really complex, both extents can be compressed
3410		 * or just one of them, which would require decompressing and
3411		 * re-compressing data (which could increase the new compressed
3412		 * size, not allowing the compressed data to fit anymore in an
3413		 * inline extent).
3414		 * So just don't support this case for now (it should be rare,
3415		 * we are not really saving space when cloning inline extents).
3416		 */
3417		return -EOPNOTSUPP;
3418	}
3419
3420	btrfs_release_path(path);
3421	ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3422	if (ret)
3423		return ret;
3424	ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3425	if (ret)
3426		return ret;
3427
3428	if (skip) {
3429		const u32 start = btrfs_file_extent_calc_inline_size(0);
3430
3431		memmove(inline_data + start, inline_data + start + skip, datal);
3432	}
3433
3434	write_extent_buffer(path->nodes[0], inline_data,
3435			    btrfs_item_ptr_offset(path->nodes[0],
3436						  path->slots[0]),
3437			    size);
3438	inode_add_bytes(dst, datal);
3439
3440	return 0;
3441}
3442
3443/**
3444 * btrfs_clone() - clone a range from inode file to another
3445 *
3446 * @src: Inode to clone from
3447 * @inode: Inode to clone to
3448 * @off: Offset within source to start clone from
3449 * @olen: Original length, passed by user, of range to clone
3450 * @olen_aligned: Block-aligned value of olen
3451 * @destoff: Offset within @inode to start clone
3452 * @no_time_update: Whether to update mtime/ctime on the target inode
3453 */
3454static int btrfs_clone(struct inode *src, struct inode *inode,
3455		       const u64 off, const u64 olen, const u64 olen_aligned,
3456		       const u64 destoff, int no_time_update)
3457{
3458	struct btrfs_root *root = BTRFS_I(inode)->root;
3459	struct btrfs_path *path = NULL;
3460	struct extent_buffer *leaf;
3461	struct btrfs_trans_handle *trans;
3462	char *buf = NULL;
3463	struct btrfs_key key;
3464	u32 nritems;
3465	int slot;
3466	int ret;
3467	const u64 len = olen_aligned;
3468	u64 last_dest_end = destoff;
3469
3470	ret = -ENOMEM;
3471	buf = vmalloc(root->nodesize);
3472	if (!buf)
3473		return ret;
3474
3475	path = btrfs_alloc_path();
3476	if (!path) {
3477		vfree(buf);
3478		return ret;
3479	}
3480
3481	path->reada = READA_FORWARD;
3482	/* clone data */
3483	key.objectid = btrfs_ino(src);
3484	key.type = BTRFS_EXTENT_DATA_KEY;
3485	key.offset = off;
3486
3487	while (1) {
3488		u64 next_key_min_offset = key.offset + 1;
3489
3490		/*
3491		 * note the key will change type as we walk through the
3492		 * tree.
3493		 */
3494		path->leave_spinning = 1;
3495		ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3496				0, 0);
3497		if (ret < 0)
3498			goto out;
3499		/*
3500		 * First search, if no extent item that starts at offset off was
3501		 * found but the previous item is an extent item, it's possible
3502		 * it might overlap our target range, therefore process it.
3503		 */
3504		if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3505			btrfs_item_key_to_cpu(path->nodes[0], &key,
3506					      path->slots[0] - 1);
3507			if (key.type == BTRFS_EXTENT_DATA_KEY)
3508				path->slots[0]--;
3509		}
3510
3511		nritems = btrfs_header_nritems(path->nodes[0]);
3512process_slot:
3513		if (path->slots[0] >= nritems) {
3514			ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3515			if (ret < 0)
3516				goto out;
3517			if (ret > 0)
3518				break;
3519			nritems = btrfs_header_nritems(path->nodes[0]);
3520		}
3521		leaf = path->nodes[0];
3522		slot = path->slots[0];
3523
3524		btrfs_item_key_to_cpu(leaf, &key, slot);
3525		if (key.type > BTRFS_EXTENT_DATA_KEY ||
3526		    key.objectid != btrfs_ino(src))
3527			break;
3528
3529		if (key.type == BTRFS_EXTENT_DATA_KEY) {
3530			struct btrfs_file_extent_item *extent;
3531			int type;
3532			u32 size;
3533			struct btrfs_key new_key;
3534			u64 disko = 0, diskl = 0;
3535			u64 datao = 0, datal = 0;
3536			u8 comp;
3537			u64 drop_start;
 
 
 
 
 
3538
3539			extent = btrfs_item_ptr(leaf, slot,
3540						struct btrfs_file_extent_item);
3541			comp = btrfs_file_extent_compression(leaf, extent);
3542			type = btrfs_file_extent_type(leaf, extent);
3543			if (type == BTRFS_FILE_EXTENT_REG ||
3544			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3545				disko = btrfs_file_extent_disk_bytenr(leaf,
3546								      extent);
3547				diskl = btrfs_file_extent_disk_num_bytes(leaf,
3548								 extent);
3549				datao = btrfs_file_extent_offset(leaf, extent);
3550				datal = btrfs_file_extent_num_bytes(leaf,
3551								    extent);
3552			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3553				/* take upper bound, may be compressed */
3554				datal = btrfs_file_extent_ram_bytes(leaf,
3555								    extent);
3556			}
 
3557
3558			/*
3559			 * The first search might have left us at an extent
3560			 * item that ends before our target range's start, can
3561			 * happen if we have holes and NO_HOLES feature enabled.
3562			 */
3563			if (key.offset + datal <= off) {
3564				path->slots[0]++;
3565				goto process_slot;
3566			} else if (key.offset >= off + len) {
3567				break;
3568			}
3569			next_key_min_offset = key.offset + datal;
3570			size = btrfs_item_size_nr(leaf, slot);
3571			read_extent_buffer(leaf, buf,
3572					   btrfs_item_ptr_offset(leaf, slot),
3573					   size);
3574
3575			btrfs_release_path(path);
3576			path->leave_spinning = 0;
3577
3578			memcpy(&new_key, &key, sizeof(new_key));
3579			new_key.objectid = btrfs_ino(inode);
3580			if (off <= key.offset)
3581				new_key.offset = key.offset + destoff - off;
3582			else
3583				new_key.offset = destoff;
3584
3585			/*
3586			 * Deal with a hole that doesn't have an extent item
3587			 * that represents it (NO_HOLES feature enabled).
3588			 * This hole is either in the middle of the cloning
3589			 * range or at the beginning (fully overlaps it or
3590			 * partially overlaps it).
3591			 */
3592			if (new_key.offset != last_dest_end)
3593				drop_start = last_dest_end;
3594			else
3595				drop_start = new_key.offset;
3596
3597			/*
3598			 * 1 - adjusting old extent (we may have to split it)
3599			 * 1 - add new extent
3600			 * 1 - inode update
3601			 */
3602			trans = btrfs_start_transaction(root, 3);
3603			if (IS_ERR(trans)) {
3604				ret = PTR_ERR(trans);
3605				goto out;
3606			}
3607
3608			if (type == BTRFS_FILE_EXTENT_REG ||
3609			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3610				/*
3611				 *    a  | --- range to clone ---|  b
3612				 * | ------------- extent ------------- |
3613				 */
3614
3615				/* subtract range b */
3616				if (key.offset + datal > off + len)
3617					datal = off + len - key.offset;
3618
3619				/* subtract range a */
3620				if (off > key.offset) {
3621					datao += off - key.offset;
3622					datal -= off - key.offset;
3623				}
3624
3625				ret = btrfs_drop_extents(trans, root, inode,
3626							 drop_start,
3627							 new_key.offset + datal,
3628							 1);
3629				if (ret) {
3630					if (ret != -EOPNOTSUPP)
3631						btrfs_abort_transaction(trans,
3632								root, ret);
3633					btrfs_end_transaction(trans, root);
3634					goto out;
3635				}
3636
3637				ret = btrfs_insert_empty_item(trans, root, path,
3638							      &new_key, size);
3639				if (ret) {
3640					btrfs_abort_transaction(trans, root,
3641								ret);
3642					btrfs_end_transaction(trans, root);
3643					goto out;
3644				}
3645
3646				leaf = path->nodes[0];
3647				slot = path->slots[0];
3648				write_extent_buffer(leaf, buf,
3649					    btrfs_item_ptr_offset(leaf, slot),
3650					    size);
3651
3652				extent = btrfs_item_ptr(leaf, slot,
3653						struct btrfs_file_extent_item);
3654
3655				/* disko == 0 means it's a hole */
3656				if (!disko)
3657					datao = 0;
3658
3659				btrfs_set_file_extent_offset(leaf, extent,
3660							     datao);
3661				btrfs_set_file_extent_num_bytes(leaf, extent,
3662								datal);
3663
3664				if (disko) {
3665					inode_add_bytes(inode, datal);
3666					ret = btrfs_inc_extent_ref(trans, root,
3667							disko, diskl, 0,
3668							root->root_key.objectid,
3669							btrfs_ino(inode),
3670							new_key.offset - datao);
3671					if (ret) {
3672						btrfs_abort_transaction(trans,
3673									root,
3674									ret);
3675						btrfs_end_transaction(trans,
3676								      root);
3677						goto out;
3678
3679					}
3680				}
3681			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3682				u64 skip = 0;
3683				u64 trim = 0;
3684
3685				if (off > key.offset) {
3686					skip = off - key.offset;
3687					new_key.offset += skip;
3688				}
3689
3690				if (key.offset + datal > off + len)
3691					trim = key.offset + datal - (off + len);
3692
3693				if (comp && (skip || trim)) {
3694					ret = -EINVAL;
3695					btrfs_end_transaction(trans, root);
3696					goto out;
3697				}
3698				size -= skip + trim;
3699				datal -= skip + trim;
3700
3701				ret = clone_copy_inline_extent(src, inode,
3702							       trans, path,
3703							       &new_key,
3704							       drop_start,
3705							       datal,
3706							       skip, size, buf);
3707				if (ret) {
3708					if (ret != -EOPNOTSUPP)
3709						btrfs_abort_transaction(trans,
3710									root,
3711									ret);
3712					btrfs_end_transaction(trans, root);
3713					goto out;
 
 
3714				}
 
3715				leaf = path->nodes[0];
3716				slot = path->slots[0];
 
 
 
 
3717			}
3718
3719			/* If we have an implicit hole (NO_HOLES feature). */
3720			if (drop_start < new_key.offset)
3721				clone_update_extent_map(inode, trans,
3722						NULL, drop_start,
3723						new_key.offset - drop_start);
3724
3725			clone_update_extent_map(inode, trans, path, 0, 0);
3726
3727			btrfs_mark_buffer_dirty(leaf);
3728			btrfs_release_path(path);
3729
3730			last_dest_end = ALIGN(new_key.offset + datal,
3731					      root->sectorsize);
3732			ret = clone_finish_inode_update(trans, inode,
3733							last_dest_end,
3734							destoff, olen,
3735							no_time_update);
3736			if (ret)
3737				goto out;
3738			if (new_key.offset + datal >= destoff + len)
3739				break;
3740		}
3741		btrfs_release_path(path);
3742		key.offset = next_key_min_offset;
3743	}
3744	ret = 0;
3745
3746	if (last_dest_end < destoff + len) {
3747		/*
3748		 * We have an implicit hole (NO_HOLES feature is enabled) that
3749		 * fully or partially overlaps our cloning range at its end.
3750		 */
3751		btrfs_release_path(path);
 
 
 
 
3752
3753		/*
3754		 * 1 - remove extent(s)
3755		 * 1 - inode update
3756		 */
3757		trans = btrfs_start_transaction(root, 2);
3758		if (IS_ERR(trans)) {
3759			ret = PTR_ERR(trans);
3760			goto out;
3761		}
3762		ret = btrfs_drop_extents(trans, root, inode,
3763					 last_dest_end, destoff + len, 1);
3764		if (ret) {
3765			if (ret != -EOPNOTSUPP)
3766				btrfs_abort_transaction(trans, root, ret);
3767			btrfs_end_transaction(trans, root);
3768			goto out;
3769		}
3770		clone_update_extent_map(inode, trans, NULL, last_dest_end,
3771					destoff + len - last_dest_end);
3772		ret = clone_finish_inode_update(trans, inode, destoff + len,
3773						destoff, olen, no_time_update);
3774	}
3775
3776out:
 
 
 
 
 
 
3777	btrfs_free_path(path);
3778	vfree(buf);
 
 
 
3779	return ret;
3780}
3781
3782static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3783					u64 off, u64 olen, u64 destoff)
3784{
3785	struct inode *inode = file_inode(file);
3786	struct inode *src = file_inode(file_src);
3787	struct btrfs_root *root = BTRFS_I(inode)->root;
3788	int ret;
3789	u64 len = olen;
3790	u64 bs = root->fs_info->sb->s_blocksize;
3791	int same_inode = src == inode;
3792
3793	/*
3794	 * TODO:
3795	 * - split compressed inline extents.  annoying: we need to
3796	 *   decompress into destination's address_space (the file offset
3797	 *   may change, so source mapping won't do), then recompress (or
3798	 *   otherwise reinsert) a subrange.
3799	 *
3800	 * - split destination inode's inline extents.  The inline extents can
3801	 *   be either compressed or non-compressed.
3802	 */
3803
3804	if (btrfs_root_readonly(root))
3805		return -EROFS;
3806
3807	if (file_src->f_path.mnt != file->f_path.mnt ||
3808	    src->i_sb != inode->i_sb)
3809		return -EXDEV;
3810
3811	/* don't make the dst file partly checksummed */
3812	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3813	    (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3814		return -EINVAL;
3815
3816	if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3817		return -EISDIR;
3818
3819	if (!same_inode) {
3820		btrfs_double_inode_lock(src, inode);
3821	} else {
3822		inode_lock(src);
3823	}
3824
3825	/* determine range to clone */
3826	ret = -EINVAL;
3827	if (off + len > src->i_size || off + len < off)
3828		goto out_unlock;
3829	if (len == 0)
3830		olen = len = src->i_size - off;
3831	/* if we extend to eof, continue to block boundary */
3832	if (off + len == src->i_size)
3833		len = ALIGN(src->i_size, bs) - off;
3834
3835	if (len == 0) {
3836		ret = 0;
3837		goto out_unlock;
3838	}
3839
3840	/* verify the end result is block aligned */
3841	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3842	    !IS_ALIGNED(destoff, bs))
3843		goto out_unlock;
3844
3845	/* verify if ranges are overlapped within the same file */
3846	if (same_inode) {
3847		if (destoff + len > off && destoff < off + len)
3848			goto out_unlock;
3849	}
3850
3851	if (destoff > inode->i_size) {
3852		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3853		if (ret)
3854			goto out_unlock;
3855	}
3856
3857	/*
3858	 * Lock the target range too. Right after we replace the file extent
3859	 * items in the fs tree (which now point to the cloned data), we might
3860	 * have a worker replace them with extent items relative to a write
3861	 * operation that was issued before this clone operation (i.e. confront
3862	 * with inode.c:btrfs_finish_ordered_io).
3863	 */
3864	if (same_inode) {
3865		u64 lock_start = min_t(u64, off, destoff);
3866		u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3867
3868		ret = lock_extent_range(src, lock_start, lock_len, true);
3869	} else {
3870		ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3871					       true);
3872	}
3873	ASSERT(ret == 0);
3874	if (WARN_ON(ret)) {
3875		/* ranges in the io trees already unlocked */
3876		goto out_unlock;
3877	}
3878
3879	ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3880
3881	if (same_inode) {
3882		u64 lock_start = min_t(u64, off, destoff);
3883		u64 lock_end = max_t(u64, off, destoff) + len - 1;
3884
3885		unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3886	} else {
3887		btrfs_double_extent_unlock(src, off, inode, destoff, len);
3888	}
3889	/*
3890	 * Truncate page cache pages so that future reads will see the cloned
3891	 * data immediately and not the previous data.
3892	 */
3893	truncate_inode_pages_range(&inode->i_data,
3894				round_down(destoff, PAGE_SIZE),
3895				round_up(destoff + len, PAGE_SIZE) - 1);
3896out_unlock:
3897	if (!same_inode)
3898		btrfs_double_inode_unlock(src, inode);
3899	else
3900		inode_unlock(src);
3901	return ret;
3902}
3903
3904ssize_t btrfs_copy_file_range(struct file *file_in, loff_t pos_in,
3905			      struct file *file_out, loff_t pos_out,
3906			      size_t len, unsigned int flags)
3907{
3908	ssize_t ret;
3909
3910	ret = btrfs_clone_files(file_out, file_in, pos_in, len, pos_out);
3911	if (ret == 0)
3912		ret = len;
3913	return ret;
3914}
3915
3916int btrfs_clone_file_range(struct file *src_file, loff_t off,
3917		struct file *dst_file, loff_t destoff, u64 len)
3918{
3919	return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3920}
3921
3922/*
3923 * there are many ways the trans_start and trans_end ioctls can lead
3924 * to deadlocks.  They should only be used by applications that
3925 * basically own the machine, and have a very in depth understanding
3926 * of all the possible deadlocks and enospc problems.
3927 */
3928static long btrfs_ioctl_trans_start(struct file *file)
3929{
3930	struct inode *inode = file_inode(file);
3931	struct btrfs_root *root = BTRFS_I(inode)->root;
3932	struct btrfs_trans_handle *trans;
3933	int ret;
3934
3935	ret = -EPERM;
3936	if (!capable(CAP_SYS_ADMIN))
3937		goto out;
3938
3939	ret = -EINPROGRESS;
3940	if (file->private_data)
3941		goto out;
3942
3943	ret = -EROFS;
3944	if (btrfs_root_readonly(root))
3945		goto out;
3946
3947	ret = mnt_want_write_file(file);
3948	if (ret)
3949		goto out;
3950
3951	atomic_inc(&root->fs_info->open_ioctl_trans);
3952
3953	ret = -ENOMEM;
3954	trans = btrfs_start_ioctl_transaction(root);
3955	if (IS_ERR(trans))
3956		goto out_drop;
3957
3958	file->private_data = trans;
3959	return 0;
3960
3961out_drop:
3962	atomic_dec(&root->fs_info->open_ioctl_trans);
3963	mnt_drop_write_file(file);
3964out:
3965	return ret;
3966}
3967
3968static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3969{
3970	struct inode *inode = file_inode(file);
3971	struct btrfs_root *root = BTRFS_I(inode)->root;
3972	struct btrfs_root *new_root;
3973	struct btrfs_dir_item *di;
3974	struct btrfs_trans_handle *trans;
3975	struct btrfs_path *path;
3976	struct btrfs_key location;
3977	struct btrfs_disk_key disk_key;
 
 
3978	u64 objectid = 0;
3979	u64 dir_id;
3980	int ret;
3981
3982	if (!capable(CAP_SYS_ADMIN))
3983		return -EPERM;
3984
3985	ret = mnt_want_write_file(file);
3986	if (ret)
3987		return ret;
3988
3989	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3990		ret = -EFAULT;
3991		goto out;
3992	}
3993
3994	if (!objectid)
3995		objectid = BTRFS_FS_TREE_OBJECTID;
3996
3997	location.objectid = objectid;
3998	location.type = BTRFS_ROOT_ITEM_KEY;
3999	location.offset = (u64)-1;
4000
4001	new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
4002	if (IS_ERR(new_root)) {
4003		ret = PTR_ERR(new_root);
4004		goto out;
4005	}
 
4006
4007	path = btrfs_alloc_path();
4008	if (!path) {
4009		ret = -ENOMEM;
4010		goto out;
4011	}
4012	path->leave_spinning = 1;
4013
4014	trans = btrfs_start_transaction(root, 1);
4015	if (IS_ERR(trans)) {
4016		btrfs_free_path(path);
4017		ret = PTR_ERR(trans);
4018		goto out;
4019	}
4020
4021	dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
4022	di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
4023				   dir_id, "default", 7, 1);
4024	if (IS_ERR_OR_NULL(di)) {
4025		btrfs_free_path(path);
4026		btrfs_end_transaction(trans, root);
4027		btrfs_err(new_root->fs_info, "Umm, you don't have the default dir"
4028			   "item, this isn't going to work");
4029		ret = -ENOENT;
4030		goto out;
4031	}
4032
4033	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4034	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4035	btrfs_mark_buffer_dirty(path->nodes[0]);
4036	btrfs_free_path(path);
4037
4038	btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
 
 
 
 
 
4039	btrfs_end_transaction(trans, root);
4040out:
4041	mnt_drop_write_file(file);
4042	return ret;
4043}
4044
4045void btrfs_get_block_group_info(struct list_head *groups_list,
4046				struct btrfs_ioctl_space_info *space)
4047{
4048	struct btrfs_block_group_cache *block_group;
4049
4050	space->total_bytes = 0;
4051	space->used_bytes = 0;
4052	space->flags = 0;
4053	list_for_each_entry(block_group, groups_list, list) {
4054		space->flags = block_group->flags;
4055		space->total_bytes += block_group->key.offset;
4056		space->used_bytes +=
4057			btrfs_block_group_used(&block_group->item);
4058	}
4059}
4060
4061static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
4062{
4063	struct btrfs_ioctl_space_args space_args;
4064	struct btrfs_ioctl_space_info space;
4065	struct btrfs_ioctl_space_info *dest;
4066	struct btrfs_ioctl_space_info *dest_orig;
4067	struct btrfs_ioctl_space_info __user *user_dest;
4068	struct btrfs_space_info *info;
4069	u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
4070		       BTRFS_BLOCK_GROUP_SYSTEM,
4071		       BTRFS_BLOCK_GROUP_METADATA,
4072		       BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
4073	int num_types = 4;
4074	int alloc_size;
4075	int ret = 0;
4076	u64 slot_count = 0;
4077	int i, c;
4078
4079	if (copy_from_user(&space_args,
4080			   (struct btrfs_ioctl_space_args __user *)arg,
4081			   sizeof(space_args)))
4082		return -EFAULT;
4083
4084	for (i = 0; i < num_types; i++) {
4085		struct btrfs_space_info *tmp;
4086
4087		info = NULL;
4088		rcu_read_lock();
4089		list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
4090					list) {
4091			if (tmp->flags == types[i]) {
4092				info = tmp;
4093				break;
4094			}
4095		}
4096		rcu_read_unlock();
4097
4098		if (!info)
4099			continue;
4100
4101		down_read(&info->groups_sem);
4102		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4103			if (!list_empty(&info->block_groups[c]))
4104				slot_count++;
4105		}
4106		up_read(&info->groups_sem);
4107	}
4108
4109	/*
4110	 * Global block reserve, exported as a space_info
4111	 */
4112	slot_count++;
4113
4114	/* space_slots == 0 means they are asking for a count */
4115	if (space_args.space_slots == 0) {
4116		space_args.total_spaces = slot_count;
4117		goto out;
4118	}
4119
4120	slot_count = min_t(u64, space_args.space_slots, slot_count);
4121
4122	alloc_size = sizeof(*dest) * slot_count;
4123
4124	/* we generally have at most 6 or so space infos, one for each raid
4125	 * level.  So, a whole page should be more than enough for everyone
4126	 */
4127	if (alloc_size > PAGE_SIZE)
4128		return -ENOMEM;
4129
4130	space_args.total_spaces = 0;
4131	dest = kmalloc(alloc_size, GFP_KERNEL);
4132	if (!dest)
4133		return -ENOMEM;
4134	dest_orig = dest;
4135
4136	/* now we have a buffer to copy into */
4137	for (i = 0; i < num_types; i++) {
4138		struct btrfs_space_info *tmp;
4139
4140		if (!slot_count)
4141			break;
4142
4143		info = NULL;
4144		rcu_read_lock();
4145		list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
4146					list) {
4147			if (tmp->flags == types[i]) {
4148				info = tmp;
4149				break;
4150			}
4151		}
4152		rcu_read_unlock();
4153
4154		if (!info)
4155			continue;
4156		down_read(&info->groups_sem);
4157		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4158			if (!list_empty(&info->block_groups[c])) {
4159				btrfs_get_block_group_info(
4160					&info->block_groups[c], &space);
4161				memcpy(dest, &space, sizeof(space));
4162				dest++;
4163				space_args.total_spaces++;
4164				slot_count--;
4165			}
4166			if (!slot_count)
4167				break;
4168		}
4169		up_read(&info->groups_sem);
4170	}
4171
4172	/*
4173	 * Add global block reserve
4174	 */
4175	if (slot_count) {
4176		struct btrfs_block_rsv *block_rsv = &root->fs_info->global_block_rsv;
4177
4178		spin_lock(&block_rsv->lock);
4179		space.total_bytes = block_rsv->size;
4180		space.used_bytes = block_rsv->size - block_rsv->reserved;
4181		spin_unlock(&block_rsv->lock);
4182		space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4183		memcpy(dest, &space, sizeof(space));
4184		space_args.total_spaces++;
4185	}
4186
4187	user_dest = (struct btrfs_ioctl_space_info __user *)
4188		(arg + sizeof(struct btrfs_ioctl_space_args));
4189
4190	if (copy_to_user(user_dest, dest_orig, alloc_size))
4191		ret = -EFAULT;
4192
4193	kfree(dest_orig);
4194out:
4195	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4196		ret = -EFAULT;
4197
4198	return ret;
4199}
4200
4201/*
4202 * there are many ways the trans_start and trans_end ioctls can lead
4203 * to deadlocks.  They should only be used by applications that
4204 * basically own the machine, and have a very in depth understanding
4205 * of all the possible deadlocks and enospc problems.
4206 */
4207long btrfs_ioctl_trans_end(struct file *file)
4208{
4209	struct inode *inode = file_inode(file);
4210	struct btrfs_root *root = BTRFS_I(inode)->root;
4211	struct btrfs_trans_handle *trans;
4212
4213	trans = file->private_data;
4214	if (!trans)
4215		return -EINVAL;
4216	file->private_data = NULL;
4217
4218	btrfs_end_transaction(trans, root);
4219
4220	atomic_dec(&root->fs_info->open_ioctl_trans);
4221
4222	mnt_drop_write_file(file);
4223	return 0;
4224}
4225
4226static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4227					    void __user *argp)
4228{
 
4229	struct btrfs_trans_handle *trans;
4230	u64 transid;
4231	int ret;
4232
4233	trans = btrfs_attach_transaction_barrier(root);
4234	if (IS_ERR(trans)) {
4235		if (PTR_ERR(trans) != -ENOENT)
4236			return PTR_ERR(trans);
4237
4238		/* No running transaction, don't bother */
4239		transid = root->fs_info->last_trans_committed;
4240		goto out;
4241	}
4242	transid = trans->transid;
4243	ret = btrfs_commit_transaction_async(trans, root, 0);
4244	if (ret) {
4245		btrfs_end_transaction(trans, root);
4246		return ret;
4247	}
4248out:
4249	if (argp)
4250		if (copy_to_user(argp, &transid, sizeof(transid)))
4251			return -EFAULT;
4252	return 0;
4253}
4254
4255static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
4256					   void __user *argp)
4257{
 
4258	u64 transid;
4259
4260	if (argp) {
4261		if (copy_from_user(&transid, argp, sizeof(transid)))
4262			return -EFAULT;
4263	} else {
4264		transid = 0;  /* current trans */
4265	}
4266	return btrfs_wait_for_commit(root, transid);
4267}
4268
4269static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4270{
4271	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4272	struct btrfs_ioctl_scrub_args *sa;
4273	int ret;
4274
4275	if (!capable(CAP_SYS_ADMIN))
4276		return -EPERM;
4277
4278	sa = memdup_user(arg, sizeof(*sa));
4279	if (IS_ERR(sa))
4280		return PTR_ERR(sa);
4281
4282	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4283		ret = mnt_want_write_file(file);
4284		if (ret)
4285			goto out;
4286	}
4287
4288	ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
4289			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4290			      0);
4291
4292	if (copy_to_user(arg, sa, sizeof(*sa)))
4293		ret = -EFAULT;
4294
4295	if (!(sa->flags & BTRFS_SCRUB_READONLY))
4296		mnt_drop_write_file(file);
4297out:
4298	kfree(sa);
4299	return ret;
4300}
4301
4302static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
4303{
4304	if (!capable(CAP_SYS_ADMIN))
4305		return -EPERM;
4306
4307	return btrfs_scrub_cancel(root->fs_info);
4308}
4309
4310static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
4311				       void __user *arg)
4312{
4313	struct btrfs_ioctl_scrub_args *sa;
4314	int ret;
4315
4316	if (!capable(CAP_SYS_ADMIN))
4317		return -EPERM;
4318
4319	sa = memdup_user(arg, sizeof(*sa));
4320	if (IS_ERR(sa))
4321		return PTR_ERR(sa);
4322
4323	ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
4324
4325	if (copy_to_user(arg, sa, sizeof(*sa)))
4326		ret = -EFAULT;
4327
4328	kfree(sa);
4329	return ret;
4330}
4331
4332static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
4333				      void __user *arg)
4334{
4335	struct btrfs_ioctl_get_dev_stats *sa;
4336	int ret;
4337
4338	sa = memdup_user(arg, sizeof(*sa));
4339	if (IS_ERR(sa))
4340		return PTR_ERR(sa);
4341
4342	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4343		kfree(sa);
4344		return -EPERM;
4345	}
4346
4347	ret = btrfs_get_dev_stats(root, sa);
4348
4349	if (copy_to_user(arg, sa, sizeof(*sa)))
4350		ret = -EFAULT;
4351
4352	kfree(sa);
4353	return ret;
4354}
4355
4356static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
4357{
4358	struct btrfs_ioctl_dev_replace_args *p;
4359	int ret;
4360
4361	if (!capable(CAP_SYS_ADMIN))
4362		return -EPERM;
4363
4364	p = memdup_user(arg, sizeof(*p));
4365	if (IS_ERR(p))
4366		return PTR_ERR(p);
4367
4368	switch (p->cmd) {
4369	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4370		if (root->fs_info->sb->s_flags & MS_RDONLY) {
4371			ret = -EROFS;
4372			goto out;
4373		}
4374		if (atomic_xchg(
4375			&root->fs_info->mutually_exclusive_operation_running,
4376			1)) {
4377			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4378		} else {
4379			ret = btrfs_dev_replace_start(root, p);
4380			atomic_set(
4381			 &root->fs_info->mutually_exclusive_operation_running,
4382			 0);
4383		}
4384		break;
4385	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4386		btrfs_dev_replace_status(root->fs_info, p);
4387		ret = 0;
4388		break;
4389	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4390		ret = btrfs_dev_replace_cancel(root->fs_info, p);
4391		break;
4392	default:
4393		ret = -EINVAL;
4394		break;
4395	}
4396
4397	if (copy_to_user(arg, p, sizeof(*p)))
4398		ret = -EFAULT;
4399out:
4400	kfree(p);
4401	return ret;
4402}
4403
4404static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4405{
4406	int ret = 0;
4407	int i;
4408	u64 rel_ptr;
4409	int size;
4410	struct btrfs_ioctl_ino_path_args *ipa = NULL;
4411	struct inode_fs_paths *ipath = NULL;
4412	struct btrfs_path *path;
4413
4414	if (!capable(CAP_DAC_READ_SEARCH))
4415		return -EPERM;
4416
4417	path = btrfs_alloc_path();
4418	if (!path) {
4419		ret = -ENOMEM;
4420		goto out;
4421	}
4422
4423	ipa = memdup_user(arg, sizeof(*ipa));
4424	if (IS_ERR(ipa)) {
4425		ret = PTR_ERR(ipa);
4426		ipa = NULL;
4427		goto out;
4428	}
4429
4430	size = min_t(u32, ipa->size, 4096);
4431	ipath = init_ipath(size, root, path);
4432	if (IS_ERR(ipath)) {
4433		ret = PTR_ERR(ipath);
4434		ipath = NULL;
4435		goto out;
4436	}
4437
4438	ret = paths_from_inode(ipa->inum, ipath);
4439	if (ret < 0)
4440		goto out;
4441
4442	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4443		rel_ptr = ipath->fspath->val[i] -
4444			  (u64)(unsigned long)ipath->fspath->val;
4445		ipath->fspath->val[i] = rel_ptr;
4446	}
4447
4448	ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4449			   (void *)(unsigned long)ipath->fspath, size);
4450	if (ret) {
4451		ret = -EFAULT;
4452		goto out;
4453	}
4454
4455out:
4456	btrfs_free_path(path);
4457	free_ipath(ipath);
4458	kfree(ipa);
4459
4460	return ret;
4461}
4462
4463static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4464{
4465	struct btrfs_data_container *inodes = ctx;
4466	const size_t c = 3 * sizeof(u64);
4467
4468	if (inodes->bytes_left >= c) {
4469		inodes->bytes_left -= c;
4470		inodes->val[inodes->elem_cnt] = inum;
4471		inodes->val[inodes->elem_cnt + 1] = offset;
4472		inodes->val[inodes->elem_cnt + 2] = root;
4473		inodes->elem_cnt += 3;
4474	} else {
4475		inodes->bytes_missing += c - inodes->bytes_left;
4476		inodes->bytes_left = 0;
4477		inodes->elem_missed += 3;
4478	}
4479
4480	return 0;
4481}
4482
4483static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
4484					void __user *arg)
4485{
4486	int ret = 0;
4487	int size;
4488	struct btrfs_ioctl_logical_ino_args *loi;
4489	struct btrfs_data_container *inodes = NULL;
4490	struct btrfs_path *path = NULL;
4491
4492	if (!capable(CAP_SYS_ADMIN))
4493		return -EPERM;
4494
4495	loi = memdup_user(arg, sizeof(*loi));
4496	if (IS_ERR(loi)) {
4497		ret = PTR_ERR(loi);
4498		loi = NULL;
4499		goto out;
4500	}
4501
4502	path = btrfs_alloc_path();
4503	if (!path) {
4504		ret = -ENOMEM;
4505		goto out;
4506	}
4507
4508	size = min_t(u32, loi->size, SZ_64K);
4509	inodes = init_data_container(size);
4510	if (IS_ERR(inodes)) {
4511		ret = PTR_ERR(inodes);
4512		inodes = NULL;
4513		goto out;
4514	}
4515
4516	ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
4517					  build_ino_list, inodes);
4518	if (ret == -EINVAL)
4519		ret = -ENOENT;
4520	if (ret < 0)
4521		goto out;
4522
4523	ret = copy_to_user((void *)(unsigned long)loi->inodes,
4524			   (void *)(unsigned long)inodes, size);
4525	if (ret)
4526		ret = -EFAULT;
4527
4528out:
4529	btrfs_free_path(path);
4530	vfree(inodes);
4531	kfree(loi);
4532
4533	return ret;
4534}
4535
4536void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4537			       struct btrfs_ioctl_balance_args *bargs)
4538{
4539	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4540
4541	bargs->flags = bctl->flags;
4542
4543	if (atomic_read(&fs_info->balance_running))
4544		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4545	if (atomic_read(&fs_info->balance_pause_req))
4546		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4547	if (atomic_read(&fs_info->balance_cancel_req))
4548		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4549
4550	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4551	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4552	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4553
4554	if (lock) {
4555		spin_lock(&fs_info->balance_lock);
4556		memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4557		spin_unlock(&fs_info->balance_lock);
4558	} else {
4559		memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4560	}
4561}
4562
4563static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4564{
4565	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4566	struct btrfs_fs_info *fs_info = root->fs_info;
4567	struct btrfs_ioctl_balance_args *bargs;
4568	struct btrfs_balance_control *bctl;
4569	bool need_unlock; /* for mut. excl. ops lock */
4570	int ret;
4571
4572	if (!capable(CAP_SYS_ADMIN))
4573		return -EPERM;
4574
4575	ret = mnt_want_write_file(file);
4576	if (ret)
4577		return ret;
4578
4579again:
4580	if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
4581		mutex_lock(&fs_info->volume_mutex);
4582		mutex_lock(&fs_info->balance_mutex);
4583		need_unlock = true;
4584		goto locked;
4585	}
4586
4587	/*
4588	 * mut. excl. ops lock is locked.  Three possibilites:
4589	 *   (1) some other op is running
4590	 *   (2) balance is running
4591	 *   (3) balance is paused -- special case (think resume)
4592	 */
4593	mutex_lock(&fs_info->balance_mutex);
4594	if (fs_info->balance_ctl) {
4595		/* this is either (2) or (3) */
4596		if (!atomic_read(&fs_info->balance_running)) {
4597			mutex_unlock(&fs_info->balance_mutex);
4598			if (!mutex_trylock(&fs_info->volume_mutex))
4599				goto again;
4600			mutex_lock(&fs_info->balance_mutex);
4601
4602			if (fs_info->balance_ctl &&
4603			    !atomic_read(&fs_info->balance_running)) {
4604				/* this is (3) */
4605				need_unlock = false;
4606				goto locked;
4607			}
4608
4609			mutex_unlock(&fs_info->balance_mutex);
4610			mutex_unlock(&fs_info->volume_mutex);
4611			goto again;
4612		} else {
4613			/* this is (2) */
4614			mutex_unlock(&fs_info->balance_mutex);
4615			ret = -EINPROGRESS;
4616			goto out;
4617		}
4618	} else {
4619		/* this is (1) */
4620		mutex_unlock(&fs_info->balance_mutex);
4621		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4622		goto out;
4623	}
4624
4625locked:
4626	BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
4627
4628	if (arg) {
4629		bargs = memdup_user(arg, sizeof(*bargs));
4630		if (IS_ERR(bargs)) {
4631			ret = PTR_ERR(bargs);
4632			goto out_unlock;
4633		}
4634
4635		if (bargs->flags & BTRFS_BALANCE_RESUME) {
4636			if (!fs_info->balance_ctl) {
4637				ret = -ENOTCONN;
4638				goto out_bargs;
4639			}
4640
4641			bctl = fs_info->balance_ctl;
4642			spin_lock(&fs_info->balance_lock);
4643			bctl->flags |= BTRFS_BALANCE_RESUME;
4644			spin_unlock(&fs_info->balance_lock);
4645
4646			goto do_balance;
4647		}
4648	} else {
4649		bargs = NULL;
4650	}
4651
4652	if (fs_info->balance_ctl) {
4653		ret = -EINPROGRESS;
4654		goto out_bargs;
4655	}
4656
4657	bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4658	if (!bctl) {
4659		ret = -ENOMEM;
4660		goto out_bargs;
4661	}
4662
4663	bctl->fs_info = fs_info;
4664	if (arg) {
4665		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4666		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4667		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4668
4669		bctl->flags = bargs->flags;
4670	} else {
4671		/* balance everything - no filters */
4672		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4673	}
4674
4675	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4676		ret = -EINVAL;
4677		goto out_bctl;
4678	}
4679
4680do_balance:
4681	/*
4682	 * Ownership of bctl and mutually_exclusive_operation_running
4683	 * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4684	 * or, if restriper was paused all the way until unmount, in
4685	 * free_fs_info.  mutually_exclusive_operation_running is
4686	 * cleared in __cancel_balance.
4687	 */
4688	need_unlock = false;
4689
4690	ret = btrfs_balance(bctl, bargs);
4691	bctl = NULL;
4692
4693	if (arg) {
4694		if (copy_to_user(arg, bargs, sizeof(*bargs)))
4695			ret = -EFAULT;
4696	}
4697
4698out_bctl:
4699	kfree(bctl);
4700out_bargs:
4701	kfree(bargs);
4702out_unlock:
4703	mutex_unlock(&fs_info->balance_mutex);
4704	mutex_unlock(&fs_info->volume_mutex);
4705	if (need_unlock)
4706		atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
4707out:
4708	mnt_drop_write_file(file);
4709	return ret;
4710}
4711
4712static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
4713{
4714	if (!capable(CAP_SYS_ADMIN))
4715		return -EPERM;
4716
4717	switch (cmd) {
4718	case BTRFS_BALANCE_CTL_PAUSE:
4719		return btrfs_pause_balance(root->fs_info);
4720	case BTRFS_BALANCE_CTL_CANCEL:
4721		return btrfs_cancel_balance(root->fs_info);
4722	}
4723
4724	return -EINVAL;
4725}
4726
4727static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
4728					 void __user *arg)
4729{
4730	struct btrfs_fs_info *fs_info = root->fs_info;
4731	struct btrfs_ioctl_balance_args *bargs;
4732	int ret = 0;
4733
4734	if (!capable(CAP_SYS_ADMIN))
4735		return -EPERM;
4736
4737	mutex_lock(&fs_info->balance_mutex);
4738	if (!fs_info->balance_ctl) {
4739		ret = -ENOTCONN;
4740		goto out;
4741	}
4742
4743	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4744	if (!bargs) {
4745		ret = -ENOMEM;
4746		goto out;
4747	}
4748
4749	update_ioctl_balance_args(fs_info, 1, bargs);
4750
4751	if (copy_to_user(arg, bargs, sizeof(*bargs)))
4752		ret = -EFAULT;
4753
4754	kfree(bargs);
4755out:
4756	mutex_unlock(&fs_info->balance_mutex);
4757	return ret;
4758}
4759
4760static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4761{
4762	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4763	struct btrfs_ioctl_quota_ctl_args *sa;
4764	struct btrfs_trans_handle *trans = NULL;
4765	int ret;
4766	int err;
4767
4768	if (!capable(CAP_SYS_ADMIN))
4769		return -EPERM;
4770
4771	ret = mnt_want_write_file(file);
4772	if (ret)
4773		return ret;
4774
4775	sa = memdup_user(arg, sizeof(*sa));
4776	if (IS_ERR(sa)) {
4777		ret = PTR_ERR(sa);
4778		goto drop_write;
4779	}
4780
4781	down_write(&root->fs_info->subvol_sem);
4782	trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
4783	if (IS_ERR(trans)) {
4784		ret = PTR_ERR(trans);
4785		goto out;
4786	}
4787
4788	switch (sa->cmd) {
4789	case BTRFS_QUOTA_CTL_ENABLE:
4790		ret = btrfs_quota_enable(trans, root->fs_info);
4791		break;
4792	case BTRFS_QUOTA_CTL_DISABLE:
4793		ret = btrfs_quota_disable(trans, root->fs_info);
4794		break;
4795	default:
4796		ret = -EINVAL;
4797		break;
4798	}
4799
4800	err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
4801	if (err && !ret)
4802		ret = err;
4803out:
4804	kfree(sa);
4805	up_write(&root->fs_info->subvol_sem);
4806drop_write:
4807	mnt_drop_write_file(file);
4808	return ret;
4809}
4810
4811static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4812{
4813	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4814	struct btrfs_ioctl_qgroup_assign_args *sa;
4815	struct btrfs_trans_handle *trans;
4816	int ret;
4817	int err;
4818
4819	if (!capable(CAP_SYS_ADMIN))
4820		return -EPERM;
4821
4822	ret = mnt_want_write_file(file);
4823	if (ret)
4824		return ret;
4825
4826	sa = memdup_user(arg, sizeof(*sa));
4827	if (IS_ERR(sa)) {
4828		ret = PTR_ERR(sa);
4829		goto drop_write;
4830	}
4831
4832	trans = btrfs_join_transaction(root);
4833	if (IS_ERR(trans)) {
4834		ret = PTR_ERR(trans);
4835		goto out;
4836	}
4837
4838	/* FIXME: check if the IDs really exist */
4839	if (sa->assign) {
4840		ret = btrfs_add_qgroup_relation(trans, root->fs_info,
4841						sa->src, sa->dst);
4842	} else {
4843		ret = btrfs_del_qgroup_relation(trans, root->fs_info,
4844						sa->src, sa->dst);
4845	}
4846
4847	/* update qgroup status and info */
4848	err = btrfs_run_qgroups(trans, root->fs_info);
4849	if (err < 0)
4850		btrfs_std_error(root->fs_info, ret,
4851			    "failed to update qgroup status and info\n");
4852	err = btrfs_end_transaction(trans, root);
4853	if (err && !ret)
4854		ret = err;
4855
4856out:
4857	kfree(sa);
4858drop_write:
4859	mnt_drop_write_file(file);
4860	return ret;
4861}
4862
4863static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4864{
4865	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4866	struct btrfs_ioctl_qgroup_create_args *sa;
4867	struct btrfs_trans_handle *trans;
4868	int ret;
4869	int err;
4870
4871	if (!capable(CAP_SYS_ADMIN))
4872		return -EPERM;
4873
4874	ret = mnt_want_write_file(file);
4875	if (ret)
4876		return ret;
4877
4878	sa = memdup_user(arg, sizeof(*sa));
4879	if (IS_ERR(sa)) {
4880		ret = PTR_ERR(sa);
4881		goto drop_write;
4882	}
4883
4884	if (!sa->qgroupid) {
4885		ret = -EINVAL;
4886		goto out;
4887	}
4888
4889	trans = btrfs_join_transaction(root);
4890	if (IS_ERR(trans)) {
4891		ret = PTR_ERR(trans);
4892		goto out;
4893	}
4894
4895	/* FIXME: check if the IDs really exist */
4896	if (sa->create) {
4897		ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid);
4898	} else {
4899		ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
4900	}
4901
4902	err = btrfs_end_transaction(trans, root);
4903	if (err && !ret)
4904		ret = err;
4905
4906out:
4907	kfree(sa);
4908drop_write:
4909	mnt_drop_write_file(file);
4910	return ret;
4911}
4912
4913static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4914{
4915	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4916	struct btrfs_ioctl_qgroup_limit_args *sa;
4917	struct btrfs_trans_handle *trans;
4918	int ret;
4919	int err;
4920	u64 qgroupid;
4921
4922	if (!capable(CAP_SYS_ADMIN))
4923		return -EPERM;
4924
4925	ret = mnt_want_write_file(file);
4926	if (ret)
4927		return ret;
4928
4929	sa = memdup_user(arg, sizeof(*sa));
4930	if (IS_ERR(sa)) {
4931		ret = PTR_ERR(sa);
4932		goto drop_write;
4933	}
4934
4935	trans = btrfs_join_transaction(root);
4936	if (IS_ERR(trans)) {
4937		ret = PTR_ERR(trans);
4938		goto out;
4939	}
4940
4941	qgroupid = sa->qgroupid;
4942	if (!qgroupid) {
4943		/* take the current subvol as qgroup */
4944		qgroupid = root->root_key.objectid;
4945	}
4946
4947	/* FIXME: check if the IDs really exist */
4948	ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
4949
4950	err = btrfs_end_transaction(trans, root);
4951	if (err && !ret)
4952		ret = err;
4953
4954out:
4955	kfree(sa);
4956drop_write:
4957	mnt_drop_write_file(file);
4958	return ret;
4959}
4960
4961static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4962{
4963	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4964	struct btrfs_ioctl_quota_rescan_args *qsa;
4965	int ret;
4966
4967	if (!capable(CAP_SYS_ADMIN))
4968		return -EPERM;
4969
4970	ret = mnt_want_write_file(file);
4971	if (ret)
4972		return ret;
4973
4974	qsa = memdup_user(arg, sizeof(*qsa));
4975	if (IS_ERR(qsa)) {
4976		ret = PTR_ERR(qsa);
4977		goto drop_write;
4978	}
4979
4980	if (qsa->flags) {
4981		ret = -EINVAL;
4982		goto out;
4983	}
4984
4985	ret = btrfs_qgroup_rescan(root->fs_info);
4986
4987out:
4988	kfree(qsa);
4989drop_write:
4990	mnt_drop_write_file(file);
4991	return ret;
4992}
4993
4994static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
4995{
4996	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4997	struct btrfs_ioctl_quota_rescan_args *qsa;
4998	int ret = 0;
4999
5000	if (!capable(CAP_SYS_ADMIN))
5001		return -EPERM;
5002
5003	qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5004	if (!qsa)
5005		return -ENOMEM;
5006
5007	if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5008		qsa->flags = 1;
5009		qsa->progress = root->fs_info->qgroup_rescan_progress.objectid;
5010	}
5011
5012	if (copy_to_user(arg, qsa, sizeof(*qsa)))
5013		ret = -EFAULT;
5014
5015	kfree(qsa);
5016	return ret;
5017}
5018
5019static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5020{
5021	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5022
5023	if (!capable(CAP_SYS_ADMIN))
5024		return -EPERM;
5025
5026	return btrfs_qgroup_wait_for_completion(root->fs_info);
5027}
5028
5029static long _btrfs_ioctl_set_received_subvol(struct file *file,
5030					    struct btrfs_ioctl_received_subvol_args *sa)
5031{
5032	struct inode *inode = file_inode(file);
5033	struct btrfs_root *root = BTRFS_I(inode)->root;
5034	struct btrfs_root_item *root_item = &root->root_item;
5035	struct btrfs_trans_handle *trans;
5036	struct timespec ct = current_fs_time(inode->i_sb);
5037	int ret = 0;
5038	int received_uuid_changed;
5039
5040	if (!inode_owner_or_capable(inode))
5041		return -EPERM;
5042
5043	ret = mnt_want_write_file(file);
5044	if (ret < 0)
5045		return ret;
5046
5047	down_write(&root->fs_info->subvol_sem);
5048
5049	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
5050		ret = -EINVAL;
5051		goto out;
5052	}
5053
5054	if (btrfs_root_readonly(root)) {
5055		ret = -EROFS;
5056		goto out;
5057	}
5058
5059	/*
5060	 * 1 - root item
5061	 * 2 - uuid items (received uuid + subvol uuid)
5062	 */
5063	trans = btrfs_start_transaction(root, 3);
5064	if (IS_ERR(trans)) {
5065		ret = PTR_ERR(trans);
5066		trans = NULL;
5067		goto out;
5068	}
5069
5070	sa->rtransid = trans->transid;
5071	sa->rtime.sec = ct.tv_sec;
5072	sa->rtime.nsec = ct.tv_nsec;
5073
5074	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5075				       BTRFS_UUID_SIZE);
5076	if (received_uuid_changed &&
5077	    !btrfs_is_empty_uuid(root_item->received_uuid))
5078		btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
5079				    root_item->received_uuid,
5080				    BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5081				    root->root_key.objectid);
5082	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5083	btrfs_set_root_stransid(root_item, sa->stransid);
5084	btrfs_set_root_rtransid(root_item, sa->rtransid);
5085	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5086	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5087	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5088	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5089
5090	ret = btrfs_update_root(trans, root->fs_info->tree_root,
5091				&root->root_key, &root->root_item);
5092	if (ret < 0) {
5093		btrfs_end_transaction(trans, root);
5094		goto out;
5095	}
5096	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5097		ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
5098					  sa->uuid,
5099					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5100					  root->root_key.objectid);
5101		if (ret < 0 && ret != -EEXIST) {
5102			btrfs_abort_transaction(trans, root, ret);
5103			goto out;
5104		}
5105	}
5106	ret = btrfs_commit_transaction(trans, root);
5107	if (ret < 0) {
5108		btrfs_abort_transaction(trans, root, ret);
5109		goto out;
5110	}
5111
5112out:
5113	up_write(&root->fs_info->subvol_sem);
5114	mnt_drop_write_file(file);
5115	return ret;
5116}
5117
5118#ifdef CONFIG_64BIT
5119static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5120						void __user *arg)
5121{
5122	struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5123	struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5124	int ret = 0;
5125
5126	args32 = memdup_user(arg, sizeof(*args32));
5127	if (IS_ERR(args32)) {
5128		ret = PTR_ERR(args32);
5129		args32 = NULL;
5130		goto out;
5131	}
5132
5133	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5134	if (!args64) {
5135		ret = -ENOMEM;
5136		goto out;
5137	}
5138
5139	memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5140	args64->stransid = args32->stransid;
5141	args64->rtransid = args32->rtransid;
5142	args64->stime.sec = args32->stime.sec;
5143	args64->stime.nsec = args32->stime.nsec;
5144	args64->rtime.sec = args32->rtime.sec;
5145	args64->rtime.nsec = args32->rtime.nsec;
5146	args64->flags = args32->flags;
5147
5148	ret = _btrfs_ioctl_set_received_subvol(file, args64);
5149	if (ret)
5150		goto out;
5151
5152	memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5153	args32->stransid = args64->stransid;
5154	args32->rtransid = args64->rtransid;
5155	args32->stime.sec = args64->stime.sec;
5156	args32->stime.nsec = args64->stime.nsec;
5157	args32->rtime.sec = args64->rtime.sec;
5158	args32->rtime.nsec = args64->rtime.nsec;
5159	args32->flags = args64->flags;
5160
5161	ret = copy_to_user(arg, args32, sizeof(*args32));
5162	if (ret)
5163		ret = -EFAULT;
5164
5165out:
5166	kfree(args32);
5167	kfree(args64);
5168	return ret;
5169}
5170#endif
5171
5172static long btrfs_ioctl_set_received_subvol(struct file *file,
5173					    void __user *arg)
5174{
5175	struct btrfs_ioctl_received_subvol_args *sa = NULL;
5176	int ret = 0;
5177
5178	sa = memdup_user(arg, sizeof(*sa));
5179	if (IS_ERR(sa)) {
5180		ret = PTR_ERR(sa);
5181		sa = NULL;
5182		goto out;
5183	}
5184
5185	ret = _btrfs_ioctl_set_received_subvol(file, sa);
5186
5187	if (ret)
5188		goto out;
5189
5190	ret = copy_to_user(arg, sa, sizeof(*sa));
5191	if (ret)
5192		ret = -EFAULT;
5193
5194out:
5195	kfree(sa);
5196	return ret;
5197}
5198
5199static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5200{
5201	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5202	size_t len;
5203	int ret;
5204	char label[BTRFS_LABEL_SIZE];
5205
5206	spin_lock(&root->fs_info->super_lock);
5207	memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5208	spin_unlock(&root->fs_info->super_lock);
5209
5210	len = strnlen(label, BTRFS_LABEL_SIZE);
5211
5212	if (len == BTRFS_LABEL_SIZE) {
5213		btrfs_warn(root->fs_info,
5214			"label is too long, return the first %zu bytes", --len);
5215	}
5216
5217	ret = copy_to_user(arg, label, len);
5218
5219	return ret ? -EFAULT : 0;
5220}
5221
5222static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5223{
5224	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5225	struct btrfs_super_block *super_block = root->fs_info->super_copy;
5226	struct btrfs_trans_handle *trans;
5227	char label[BTRFS_LABEL_SIZE];
5228	int ret;
5229
5230	if (!capable(CAP_SYS_ADMIN))
5231		return -EPERM;
5232
5233	if (copy_from_user(label, arg, sizeof(label)))
5234		return -EFAULT;
5235
5236	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5237		btrfs_err(root->fs_info, "unable to set label with more than %d bytes",
5238		       BTRFS_LABEL_SIZE - 1);
5239		return -EINVAL;
5240	}
5241
5242	ret = mnt_want_write_file(file);
5243	if (ret)
5244		return ret;
5245
5246	trans = btrfs_start_transaction(root, 0);
5247	if (IS_ERR(trans)) {
5248		ret = PTR_ERR(trans);
5249		goto out_unlock;
5250	}
5251
5252	spin_lock(&root->fs_info->super_lock);
5253	strcpy(super_block->label, label);
5254	spin_unlock(&root->fs_info->super_lock);
5255	ret = btrfs_commit_transaction(trans, root);
5256
5257out_unlock:
5258	mnt_drop_write_file(file);
5259	return ret;
5260}
5261
5262#define INIT_FEATURE_FLAGS(suffix) \
5263	{ .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5264	  .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5265	  .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5266
5267int btrfs_ioctl_get_supported_features(void __user *arg)
5268{
5269	static const struct btrfs_ioctl_feature_flags features[3] = {
5270		INIT_FEATURE_FLAGS(SUPP),
5271		INIT_FEATURE_FLAGS(SAFE_SET),
5272		INIT_FEATURE_FLAGS(SAFE_CLEAR)
5273	};
5274
5275	if (copy_to_user(arg, &features, sizeof(features)))
5276		return -EFAULT;
5277
5278	return 0;
5279}
5280
5281static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5282{
5283	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5284	struct btrfs_super_block *super_block = root->fs_info->super_copy;
5285	struct btrfs_ioctl_feature_flags features;
5286
5287	features.compat_flags = btrfs_super_compat_flags(super_block);
5288	features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5289	features.incompat_flags = btrfs_super_incompat_flags(super_block);
5290
5291	if (copy_to_user(arg, &features, sizeof(features)))
5292		return -EFAULT;
5293
5294	return 0;
5295}
5296
5297static int check_feature_bits(struct btrfs_root *root,
5298			      enum btrfs_feature_set set,
5299			      u64 change_mask, u64 flags, u64 supported_flags,
5300			      u64 safe_set, u64 safe_clear)
5301{
5302	const char *type = btrfs_feature_set_names[set];
5303	char *names;
5304	u64 disallowed, unsupported;
5305	u64 set_mask = flags & change_mask;
5306	u64 clear_mask = ~flags & change_mask;
5307
5308	unsupported = set_mask & ~supported_flags;
5309	if (unsupported) {
5310		names = btrfs_printable_features(set, unsupported);
5311		if (names) {
5312			btrfs_warn(root->fs_info,
5313			   "this kernel does not support the %s feature bit%s",
5314			   names, strchr(names, ',') ? "s" : "");
5315			kfree(names);
5316		} else
5317			btrfs_warn(root->fs_info,
5318			   "this kernel does not support %s bits 0x%llx",
5319			   type, unsupported);
5320		return -EOPNOTSUPP;
5321	}
5322
5323	disallowed = set_mask & ~safe_set;
5324	if (disallowed) {
5325		names = btrfs_printable_features(set, disallowed);
5326		if (names) {
5327			btrfs_warn(root->fs_info,
5328			   "can't set the %s feature bit%s while mounted",
5329			   names, strchr(names, ',') ? "s" : "");
5330			kfree(names);
5331		} else
5332			btrfs_warn(root->fs_info,
5333			   "can't set %s bits 0x%llx while mounted",
5334			   type, disallowed);
5335		return -EPERM;
5336	}
5337
5338	disallowed = clear_mask & ~safe_clear;
5339	if (disallowed) {
5340		names = btrfs_printable_features(set, disallowed);
5341		if (names) {
5342			btrfs_warn(root->fs_info,
5343			   "can't clear the %s feature bit%s while mounted",
5344			   names, strchr(names, ',') ? "s" : "");
5345			kfree(names);
5346		} else
5347			btrfs_warn(root->fs_info,
5348			   "can't clear %s bits 0x%llx while mounted",
5349			   type, disallowed);
5350		return -EPERM;
5351	}
5352
5353	return 0;
5354}
5355
5356#define check_feature(root, change_mask, flags, mask_base)	\
5357check_feature_bits(root, FEAT_##mask_base, change_mask, flags,	\
5358		   BTRFS_FEATURE_ ## mask_base ## _SUPP,	\
5359		   BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,	\
5360		   BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5361
5362static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5363{
5364	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5365	struct btrfs_super_block *super_block = root->fs_info->super_copy;
5366	struct btrfs_ioctl_feature_flags flags[2];
5367	struct btrfs_trans_handle *trans;
5368	u64 newflags;
5369	int ret;
5370
5371	if (!capable(CAP_SYS_ADMIN))
5372		return -EPERM;
5373
5374	if (copy_from_user(flags, arg, sizeof(flags)))
5375		return -EFAULT;
5376
5377	/* Nothing to do */
5378	if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5379	    !flags[0].incompat_flags)
5380		return 0;
5381
5382	ret = check_feature(root, flags[0].compat_flags,
5383			    flags[1].compat_flags, COMPAT);
5384	if (ret)
5385		return ret;
5386
5387	ret = check_feature(root, flags[0].compat_ro_flags,
5388			    flags[1].compat_ro_flags, COMPAT_RO);
5389	if (ret)
5390		return ret;
5391
5392	ret = check_feature(root, flags[0].incompat_flags,
5393			    flags[1].incompat_flags, INCOMPAT);
5394	if (ret)
5395		return ret;
5396
5397	trans = btrfs_start_transaction(root, 0);
5398	if (IS_ERR(trans))
5399		return PTR_ERR(trans);
5400
5401	spin_lock(&root->fs_info->super_lock);
5402	newflags = btrfs_super_compat_flags(super_block);
5403	newflags |= flags[0].compat_flags & flags[1].compat_flags;
5404	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5405	btrfs_set_super_compat_flags(super_block, newflags);
5406
5407	newflags = btrfs_super_compat_ro_flags(super_block);
5408	newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5409	newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5410	btrfs_set_super_compat_ro_flags(super_block, newflags);
5411
5412	newflags = btrfs_super_incompat_flags(super_block);
5413	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5414	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5415	btrfs_set_super_incompat_flags(super_block, newflags);
5416	spin_unlock(&root->fs_info->super_lock);
5417
5418	return btrfs_commit_transaction(trans, root);
5419}
5420
5421long btrfs_ioctl(struct file *file, unsigned int
5422		cmd, unsigned long arg)
5423{
5424	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5425	void __user *argp = (void __user *)arg;
5426
5427	switch (cmd) {
5428	case FS_IOC_GETFLAGS:
5429		return btrfs_ioctl_getflags(file, argp);
5430	case FS_IOC_SETFLAGS:
5431		return btrfs_ioctl_setflags(file, argp);
5432	case FS_IOC_GETVERSION:
5433		return btrfs_ioctl_getversion(file, argp);
5434	case FITRIM:
5435		return btrfs_ioctl_fitrim(file, argp);
5436	case BTRFS_IOC_SNAP_CREATE:
5437		return btrfs_ioctl_snap_create(file, argp, 0);
5438	case BTRFS_IOC_SNAP_CREATE_V2:
5439		return btrfs_ioctl_snap_create_v2(file, argp, 0);
5440	case BTRFS_IOC_SUBVOL_CREATE:
5441		return btrfs_ioctl_snap_create(file, argp, 1);
5442	case BTRFS_IOC_SUBVOL_CREATE_V2:
5443		return btrfs_ioctl_snap_create_v2(file, argp, 1);
5444	case BTRFS_IOC_SNAP_DESTROY:
5445		return btrfs_ioctl_snap_destroy(file, argp);
5446	case BTRFS_IOC_SUBVOL_GETFLAGS:
5447		return btrfs_ioctl_subvol_getflags(file, argp);
5448	case BTRFS_IOC_SUBVOL_SETFLAGS:
5449		return btrfs_ioctl_subvol_setflags(file, argp);
5450	case BTRFS_IOC_DEFAULT_SUBVOL:
5451		return btrfs_ioctl_default_subvol(file, argp);
5452	case BTRFS_IOC_DEFRAG:
5453		return btrfs_ioctl_defrag(file, NULL);
5454	case BTRFS_IOC_DEFRAG_RANGE:
5455		return btrfs_ioctl_defrag(file, argp);
5456	case BTRFS_IOC_RESIZE:
5457		return btrfs_ioctl_resize(file, argp);
5458	case BTRFS_IOC_ADD_DEV:
5459		return btrfs_ioctl_add_dev(root, argp);
5460	case BTRFS_IOC_RM_DEV:
5461		return btrfs_ioctl_rm_dev(file, argp);
5462	case BTRFS_IOC_FS_INFO:
5463		return btrfs_ioctl_fs_info(root, argp);
5464	case BTRFS_IOC_DEV_INFO:
5465		return btrfs_ioctl_dev_info(root, argp);
5466	case BTRFS_IOC_BALANCE:
5467		return btrfs_ioctl_balance(file, NULL);
 
 
 
 
5468	case BTRFS_IOC_TRANS_START:
5469		return btrfs_ioctl_trans_start(file);
5470	case BTRFS_IOC_TRANS_END:
5471		return btrfs_ioctl_trans_end(file);
5472	case BTRFS_IOC_TREE_SEARCH:
5473		return btrfs_ioctl_tree_search(file, argp);
5474	case BTRFS_IOC_TREE_SEARCH_V2:
5475		return btrfs_ioctl_tree_search_v2(file, argp);
5476	case BTRFS_IOC_INO_LOOKUP:
5477		return btrfs_ioctl_ino_lookup(file, argp);
5478	case BTRFS_IOC_INO_PATHS:
5479		return btrfs_ioctl_ino_to_path(root, argp);
5480	case BTRFS_IOC_LOGICAL_INO:
5481		return btrfs_ioctl_logical_to_ino(root, argp);
5482	case BTRFS_IOC_SPACE_INFO:
5483		return btrfs_ioctl_space_info(root, argp);
5484	case BTRFS_IOC_SYNC: {
5485		int ret;
5486
5487		ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1);
5488		if (ret)
5489			return ret;
5490		ret = btrfs_sync_fs(file_inode(file)->i_sb, 1);
5491		/*
5492		 * The transaction thread may want to do more work,
5493		 * namely it pokes the cleaner ktread that will start
5494		 * processing uncleaned subvols.
5495		 */
5496		wake_up_process(root->fs_info->transaction_kthread);
5497		return ret;
5498	}
5499	case BTRFS_IOC_START_SYNC:
5500		return btrfs_ioctl_start_sync(root, argp);
5501	case BTRFS_IOC_WAIT_SYNC:
5502		return btrfs_ioctl_wait_sync(root, argp);
5503	case BTRFS_IOC_SCRUB:
5504		return btrfs_ioctl_scrub(file, argp);
5505	case BTRFS_IOC_SCRUB_CANCEL:
5506		return btrfs_ioctl_scrub_cancel(root, argp);
5507	case BTRFS_IOC_SCRUB_PROGRESS:
5508		return btrfs_ioctl_scrub_progress(root, argp);
5509	case BTRFS_IOC_BALANCE_V2:
5510		return btrfs_ioctl_balance(file, argp);
5511	case BTRFS_IOC_BALANCE_CTL:
5512		return btrfs_ioctl_balance_ctl(root, arg);
5513	case BTRFS_IOC_BALANCE_PROGRESS:
5514		return btrfs_ioctl_balance_progress(root, argp);
5515	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5516		return btrfs_ioctl_set_received_subvol(file, argp);
5517#ifdef CONFIG_64BIT
5518	case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5519		return btrfs_ioctl_set_received_subvol_32(file, argp);
5520#endif
5521	case BTRFS_IOC_SEND:
5522		return btrfs_ioctl_send(file, argp);
5523	case BTRFS_IOC_GET_DEV_STATS:
5524		return btrfs_ioctl_get_dev_stats(root, argp);
5525	case BTRFS_IOC_QUOTA_CTL:
5526		return btrfs_ioctl_quota_ctl(file, argp);
5527	case BTRFS_IOC_QGROUP_ASSIGN:
5528		return btrfs_ioctl_qgroup_assign(file, argp);
5529	case BTRFS_IOC_QGROUP_CREATE:
5530		return btrfs_ioctl_qgroup_create(file, argp);
5531	case BTRFS_IOC_QGROUP_LIMIT:
5532		return btrfs_ioctl_qgroup_limit(file, argp);
5533	case BTRFS_IOC_QUOTA_RESCAN:
5534		return btrfs_ioctl_quota_rescan(file, argp);
5535	case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5536		return btrfs_ioctl_quota_rescan_status(file, argp);
5537	case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5538		return btrfs_ioctl_quota_rescan_wait(file, argp);
5539	case BTRFS_IOC_DEV_REPLACE:
5540		return btrfs_ioctl_dev_replace(root, argp);
5541	case BTRFS_IOC_GET_FSLABEL:
5542		return btrfs_ioctl_get_fslabel(file, argp);
5543	case BTRFS_IOC_SET_FSLABEL:
5544		return btrfs_ioctl_set_fslabel(file, argp);
5545	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5546		return btrfs_ioctl_get_supported_features(argp);
5547	case BTRFS_IOC_GET_FEATURES:
5548		return btrfs_ioctl_get_features(file, argp);
5549	case BTRFS_IOC_SET_FEATURES:
5550		return btrfs_ioctl_set_features(file, argp);
5551	}
5552
5553	return -ENOTTY;
5554}