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