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Btrfs: introduce per-subvolume ordered extent list
[deliverable/linux.git] / fs / btrfs / super.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
22 #include <linux/fs.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mount.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
39 #include <linux/miscdevice.h>
40 #include <linux/magic.h>
41 #include <linux/slab.h>
42 #include <linux/cleancache.h>
43 #include <linux/ratelimit.h>
44 #include <linux/btrfs.h>
45 #include "compat.h"
46 #include "delayed-inode.h"
47 #include "ctree.h"
48 #include "disk-io.h"
49 #include "transaction.h"
50 #include "btrfs_inode.h"
51 #include "print-tree.h"
52 #include "xattr.h"
53 #include "volumes.h"
54 #include "export.h"
55 #include "compression.h"
56 #include "rcu-string.h"
57 #include "dev-replace.h"
58 #include "free-space-cache.h"
59
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/btrfs.h>
62
63 static const struct super_operations btrfs_super_ops;
64 static struct file_system_type btrfs_fs_type;
65
66 static const char *btrfs_decode_error(int errno)
67 {
68 char *errstr = "unknown";
69
70 switch (errno) {
71 case -EIO:
72 errstr = "IO failure";
73 break;
74 case -ENOMEM:
75 errstr = "Out of memory";
76 break;
77 case -EROFS:
78 errstr = "Readonly filesystem";
79 break;
80 case -EEXIST:
81 errstr = "Object already exists";
82 break;
83 case -ENOSPC:
84 errstr = "No space left";
85 break;
86 case -ENOENT:
87 errstr = "No such entry";
88 break;
89 }
90
91 return errstr;
92 }
93
94 static void save_error_info(struct btrfs_fs_info *fs_info)
95 {
96 /*
97 * today we only save the error info into ram. Long term we'll
98 * also send it down to the disk
99 */
100 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
101 }
102
103 /* btrfs handle error by forcing the filesystem readonly */
104 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
105 {
106 struct super_block *sb = fs_info->sb;
107
108 if (sb->s_flags & MS_RDONLY)
109 return;
110
111 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
112 sb->s_flags |= MS_RDONLY;
113 btrfs_info(fs_info, "forced readonly");
114 /*
115 * Note that a running device replace operation is not
116 * canceled here although there is no way to update
117 * the progress. It would add the risk of a deadlock,
118 * therefore the canceling is ommited. The only penalty
119 * is that some I/O remains active until the procedure
120 * completes. The next time when the filesystem is
121 * mounted writeable again, the device replace
122 * operation continues.
123 */
124 }
125 }
126
127 #ifdef CONFIG_PRINTK
128 /*
129 * __btrfs_std_error decodes expected errors from the caller and
130 * invokes the approciate error response.
131 */
132 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
133 unsigned int line, int errno, const char *fmt, ...)
134 {
135 struct super_block *sb = fs_info->sb;
136 const char *errstr;
137
138 /*
139 * Special case: if the error is EROFS, and we're already
140 * under MS_RDONLY, then it is safe here.
141 */
142 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
143 return;
144
145 errstr = btrfs_decode_error(errno);
146 if (fmt) {
147 struct va_format vaf;
148 va_list args;
149
150 va_start(args, fmt);
151 vaf.fmt = fmt;
152 vaf.va = &args;
153
154 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s (%pV)\n",
155 sb->s_id, function, line, errno, errstr, &vaf);
156 va_end(args);
157 } else {
158 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s\n",
159 sb->s_id, function, line, errno, errstr);
160 }
161
162 /* Don't go through full error handling during mount */
163 save_error_info(fs_info);
164 if (sb->s_flags & MS_BORN)
165 btrfs_handle_error(fs_info);
166 }
167
168 static const char * const logtypes[] = {
169 "emergency",
170 "alert",
171 "critical",
172 "error",
173 "warning",
174 "notice",
175 "info",
176 "debug",
177 };
178
179 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
180 {
181 struct super_block *sb = fs_info->sb;
182 char lvl[4];
183 struct va_format vaf;
184 va_list args;
185 const char *type = logtypes[4];
186 int kern_level;
187
188 va_start(args, fmt);
189
190 kern_level = printk_get_level(fmt);
191 if (kern_level) {
192 size_t size = printk_skip_level(fmt) - fmt;
193 memcpy(lvl, fmt, size);
194 lvl[size] = '\0';
195 fmt += size;
196 type = logtypes[kern_level - '0'];
197 } else
198 *lvl = '\0';
199
200 vaf.fmt = fmt;
201 vaf.va = &args;
202
203 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
204
205 va_end(args);
206 }
207
208 #else
209
210 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
211 unsigned int line, int errno, const char *fmt, ...)
212 {
213 struct super_block *sb = fs_info->sb;
214
215 /*
216 * Special case: if the error is EROFS, and we're already
217 * under MS_RDONLY, then it is safe here.
218 */
219 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
220 return;
221
222 /* Don't go through full error handling during mount */
223 if (sb->s_flags & MS_BORN) {
224 save_error_info(fs_info);
225 btrfs_handle_error(fs_info);
226 }
227 }
228 #endif
229
230 /*
231 * We only mark the transaction aborted and then set the file system read-only.
232 * This will prevent new transactions from starting or trying to join this
233 * one.
234 *
235 * This means that error recovery at the call site is limited to freeing
236 * any local memory allocations and passing the error code up without
237 * further cleanup. The transaction should complete as it normally would
238 * in the call path but will return -EIO.
239 *
240 * We'll complete the cleanup in btrfs_end_transaction and
241 * btrfs_commit_transaction.
242 */
243 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
244 struct btrfs_root *root, const char *function,
245 unsigned int line, int errno)
246 {
247 /*
248 * Report first abort since mount
249 */
250 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
251 &root->fs_info->fs_state)) {
252 WARN(1, KERN_DEBUG "btrfs: Transaction aborted (error %d)\n",
253 errno);
254 }
255 trans->aborted = errno;
256 /* Nothing used. The other threads that have joined this
257 * transaction may be able to continue. */
258 if (!trans->blocks_used) {
259 const char *errstr;
260
261 errstr = btrfs_decode_error(errno);
262 btrfs_warn(root->fs_info,
263 "%s:%d: Aborting unused transaction(%s).",
264 function, line, errstr);
265 return;
266 }
267 ACCESS_ONCE(trans->transaction->aborted) = errno;
268 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
269 }
270 /*
271 * __btrfs_panic decodes unexpected, fatal errors from the caller,
272 * issues an alert, and either panics or BUGs, depending on mount options.
273 */
274 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
275 unsigned int line, int errno, const char *fmt, ...)
276 {
277 char *s_id = "<unknown>";
278 const char *errstr;
279 struct va_format vaf = { .fmt = fmt };
280 va_list args;
281
282 if (fs_info)
283 s_id = fs_info->sb->s_id;
284
285 va_start(args, fmt);
286 vaf.va = &args;
287
288 errstr = btrfs_decode_error(errno);
289 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
290 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
291 s_id, function, line, &vaf, errno, errstr);
292
293 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
294 s_id, function, line, &vaf, errno, errstr);
295 va_end(args);
296 /* Caller calls BUG() */
297 }
298
299 static void btrfs_put_super(struct super_block *sb)
300 {
301 (void)close_ctree(btrfs_sb(sb)->tree_root);
302 /* FIXME: need to fix VFS to return error? */
303 /* AV: return it _where_? ->put_super() can be triggered by any number
304 * of async events, up to and including delivery of SIGKILL to the
305 * last process that kept it busy. Or segfault in the aforementioned
306 * process... Whom would you report that to?
307 */
308 }
309
310 enum {
311 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
312 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
313 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
314 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
315 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
316 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
317 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
318 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
319 Opt_check_integrity, Opt_check_integrity_including_extent_data,
320 Opt_check_integrity_print_mask, Opt_fatal_errors,
321 Opt_err,
322 };
323
324 static match_table_t tokens = {
325 {Opt_degraded, "degraded"},
326 {Opt_subvol, "subvol=%s"},
327 {Opt_subvolid, "subvolid=%d"},
328 {Opt_device, "device=%s"},
329 {Opt_nodatasum, "nodatasum"},
330 {Opt_nodatacow, "nodatacow"},
331 {Opt_nobarrier, "nobarrier"},
332 {Opt_max_inline, "max_inline=%s"},
333 {Opt_alloc_start, "alloc_start=%s"},
334 {Opt_thread_pool, "thread_pool=%d"},
335 {Opt_compress, "compress"},
336 {Opt_compress_type, "compress=%s"},
337 {Opt_compress_force, "compress-force"},
338 {Opt_compress_force_type, "compress-force=%s"},
339 {Opt_ssd, "ssd"},
340 {Opt_ssd_spread, "ssd_spread"},
341 {Opt_nossd, "nossd"},
342 {Opt_noacl, "noacl"},
343 {Opt_notreelog, "notreelog"},
344 {Opt_flushoncommit, "flushoncommit"},
345 {Opt_ratio, "metadata_ratio=%d"},
346 {Opt_discard, "discard"},
347 {Opt_space_cache, "space_cache"},
348 {Opt_clear_cache, "clear_cache"},
349 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
350 {Opt_enospc_debug, "enospc_debug"},
351 {Opt_subvolrootid, "subvolrootid=%d"},
352 {Opt_defrag, "autodefrag"},
353 {Opt_inode_cache, "inode_cache"},
354 {Opt_no_space_cache, "nospace_cache"},
355 {Opt_recovery, "recovery"},
356 {Opt_skip_balance, "skip_balance"},
357 {Opt_check_integrity, "check_int"},
358 {Opt_check_integrity_including_extent_data, "check_int_data"},
359 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
360 {Opt_fatal_errors, "fatal_errors=%s"},
361 {Opt_err, NULL},
362 };
363
364 /*
365 * Regular mount options parser. Everything that is needed only when
366 * reading in a new superblock is parsed here.
367 * XXX JDM: This needs to be cleaned up for remount.
368 */
369 int btrfs_parse_options(struct btrfs_root *root, char *options)
370 {
371 struct btrfs_fs_info *info = root->fs_info;
372 substring_t args[MAX_OPT_ARGS];
373 char *p, *num, *orig = NULL;
374 u64 cache_gen;
375 int intarg;
376 int ret = 0;
377 char *compress_type;
378 bool compress_force = false;
379
380 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
381 if (cache_gen)
382 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
383
384 if (!options)
385 goto out;
386
387 /*
388 * strsep changes the string, duplicate it because parse_options
389 * gets called twice
390 */
391 options = kstrdup(options, GFP_NOFS);
392 if (!options)
393 return -ENOMEM;
394
395 orig = options;
396
397 while ((p = strsep(&options, ",")) != NULL) {
398 int token;
399 if (!*p)
400 continue;
401
402 token = match_token(p, tokens, args);
403 switch (token) {
404 case Opt_degraded:
405 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
406 btrfs_set_opt(info->mount_opt, DEGRADED);
407 break;
408 case Opt_subvol:
409 case Opt_subvolid:
410 case Opt_subvolrootid:
411 case Opt_device:
412 /*
413 * These are parsed by btrfs_parse_early_options
414 * and can be happily ignored here.
415 */
416 break;
417 case Opt_nodatasum:
418 printk(KERN_INFO "btrfs: setting nodatasum\n");
419 btrfs_set_opt(info->mount_opt, NODATASUM);
420 break;
421 case Opt_nodatacow:
422 if (!btrfs_test_opt(root, COMPRESS) ||
423 !btrfs_test_opt(root, FORCE_COMPRESS)) {
424 printk(KERN_INFO "btrfs: setting nodatacow, compression disabled\n");
425 } else {
426 printk(KERN_INFO "btrfs: setting nodatacow\n");
427 }
428 info->compress_type = BTRFS_COMPRESS_NONE;
429 btrfs_clear_opt(info->mount_opt, COMPRESS);
430 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
431 btrfs_set_opt(info->mount_opt, NODATACOW);
432 btrfs_set_opt(info->mount_opt, NODATASUM);
433 break;
434 case Opt_compress_force:
435 case Opt_compress_force_type:
436 compress_force = true;
437 /* Fallthrough */
438 case Opt_compress:
439 case Opt_compress_type:
440 if (token == Opt_compress ||
441 token == Opt_compress_force ||
442 strcmp(args[0].from, "zlib") == 0) {
443 compress_type = "zlib";
444 info->compress_type = BTRFS_COMPRESS_ZLIB;
445 btrfs_set_opt(info->mount_opt, COMPRESS);
446 btrfs_clear_opt(info->mount_opt, NODATACOW);
447 btrfs_clear_opt(info->mount_opt, NODATASUM);
448 } else if (strcmp(args[0].from, "lzo") == 0) {
449 compress_type = "lzo";
450 info->compress_type = BTRFS_COMPRESS_LZO;
451 btrfs_set_opt(info->mount_opt, COMPRESS);
452 btrfs_clear_opt(info->mount_opt, NODATACOW);
453 btrfs_clear_opt(info->mount_opt, NODATASUM);
454 btrfs_set_fs_incompat(info, COMPRESS_LZO);
455 } else if (strncmp(args[0].from, "no", 2) == 0) {
456 compress_type = "no";
457 info->compress_type = BTRFS_COMPRESS_NONE;
458 btrfs_clear_opt(info->mount_opt, COMPRESS);
459 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
460 compress_force = false;
461 } else {
462 ret = -EINVAL;
463 goto out;
464 }
465
466 if (compress_force) {
467 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
468 pr_info("btrfs: force %s compression\n",
469 compress_type);
470 } else
471 pr_info("btrfs: use %s compression\n",
472 compress_type);
473 break;
474 case Opt_ssd:
475 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
476 btrfs_set_opt(info->mount_opt, SSD);
477 break;
478 case Opt_ssd_spread:
479 printk(KERN_INFO "btrfs: use spread ssd "
480 "allocation scheme\n");
481 btrfs_set_opt(info->mount_opt, SSD);
482 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
483 break;
484 case Opt_nossd:
485 printk(KERN_INFO "btrfs: not using ssd allocation "
486 "scheme\n");
487 btrfs_set_opt(info->mount_opt, NOSSD);
488 btrfs_clear_opt(info->mount_opt, SSD);
489 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
490 break;
491 case Opt_nobarrier:
492 printk(KERN_INFO "btrfs: turning off barriers\n");
493 btrfs_set_opt(info->mount_opt, NOBARRIER);
494 break;
495 case Opt_thread_pool:
496 intarg = 0;
497 match_int(&args[0], &intarg);
498 if (intarg)
499 info->thread_pool_size = intarg;
500 break;
501 case Opt_max_inline:
502 num = match_strdup(&args[0]);
503 if (num) {
504 info->max_inline = memparse(num, NULL);
505 kfree(num);
506
507 if (info->max_inline) {
508 info->max_inline = max_t(u64,
509 info->max_inline,
510 root->sectorsize);
511 }
512 printk(KERN_INFO "btrfs: max_inline at %llu\n",
513 (unsigned long long)info->max_inline);
514 }
515 break;
516 case Opt_alloc_start:
517 num = match_strdup(&args[0]);
518 if (num) {
519 mutex_lock(&info->chunk_mutex);
520 info->alloc_start = memparse(num, NULL);
521 mutex_unlock(&info->chunk_mutex);
522 kfree(num);
523 printk(KERN_INFO
524 "btrfs: allocations start at %llu\n",
525 (unsigned long long)info->alloc_start);
526 }
527 break;
528 case Opt_noacl:
529 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
530 break;
531 case Opt_notreelog:
532 printk(KERN_INFO "btrfs: disabling tree log\n");
533 btrfs_set_opt(info->mount_opt, NOTREELOG);
534 break;
535 case Opt_flushoncommit:
536 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
537 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
538 break;
539 case Opt_ratio:
540 intarg = 0;
541 match_int(&args[0], &intarg);
542 if (intarg) {
543 info->metadata_ratio = intarg;
544 printk(KERN_INFO "btrfs: metadata ratio %d\n",
545 info->metadata_ratio);
546 }
547 break;
548 case Opt_discard:
549 btrfs_set_opt(info->mount_opt, DISCARD);
550 break;
551 case Opt_space_cache:
552 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
553 break;
554 case Opt_no_space_cache:
555 printk(KERN_INFO "btrfs: disabling disk space caching\n");
556 btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
557 break;
558 case Opt_inode_cache:
559 printk(KERN_INFO "btrfs: enabling inode map caching\n");
560 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
561 break;
562 case Opt_clear_cache:
563 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
564 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
565 break;
566 case Opt_user_subvol_rm_allowed:
567 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
568 break;
569 case Opt_enospc_debug:
570 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
571 break;
572 case Opt_defrag:
573 printk(KERN_INFO "btrfs: enabling auto defrag\n");
574 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
575 break;
576 case Opt_recovery:
577 printk(KERN_INFO "btrfs: enabling auto recovery\n");
578 btrfs_set_opt(info->mount_opt, RECOVERY);
579 break;
580 case Opt_skip_balance:
581 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
582 break;
583 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
584 case Opt_check_integrity_including_extent_data:
585 printk(KERN_INFO "btrfs: enabling check integrity"
586 " including extent data\n");
587 btrfs_set_opt(info->mount_opt,
588 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
589 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
590 break;
591 case Opt_check_integrity:
592 printk(KERN_INFO "btrfs: enabling check integrity\n");
593 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
594 break;
595 case Opt_check_integrity_print_mask:
596 intarg = 0;
597 match_int(&args[0], &intarg);
598 if (intarg) {
599 info->check_integrity_print_mask = intarg;
600 printk(KERN_INFO "btrfs:"
601 " check_integrity_print_mask 0x%x\n",
602 info->check_integrity_print_mask);
603 }
604 break;
605 #else
606 case Opt_check_integrity_including_extent_data:
607 case Opt_check_integrity:
608 case Opt_check_integrity_print_mask:
609 printk(KERN_ERR "btrfs: support for check_integrity*"
610 " not compiled in!\n");
611 ret = -EINVAL;
612 goto out;
613 #endif
614 case Opt_fatal_errors:
615 if (strcmp(args[0].from, "panic") == 0)
616 btrfs_set_opt(info->mount_opt,
617 PANIC_ON_FATAL_ERROR);
618 else if (strcmp(args[0].from, "bug") == 0)
619 btrfs_clear_opt(info->mount_opt,
620 PANIC_ON_FATAL_ERROR);
621 else {
622 ret = -EINVAL;
623 goto out;
624 }
625 break;
626 case Opt_err:
627 printk(KERN_INFO "btrfs: unrecognized mount option "
628 "'%s'\n", p);
629 ret = -EINVAL;
630 goto out;
631 default:
632 break;
633 }
634 }
635 out:
636 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
637 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
638 kfree(orig);
639 return ret;
640 }
641
642 /*
643 * Parse mount options that are required early in the mount process.
644 *
645 * All other options will be parsed on much later in the mount process and
646 * only when we need to allocate a new super block.
647 */
648 static int btrfs_parse_early_options(const char *options, fmode_t flags,
649 void *holder, char **subvol_name, u64 *subvol_objectid,
650 struct btrfs_fs_devices **fs_devices)
651 {
652 substring_t args[MAX_OPT_ARGS];
653 char *device_name, *opts, *orig, *p;
654 int error = 0;
655 int intarg;
656
657 if (!options)
658 return 0;
659
660 /*
661 * strsep changes the string, duplicate it because parse_options
662 * gets called twice
663 */
664 opts = kstrdup(options, GFP_KERNEL);
665 if (!opts)
666 return -ENOMEM;
667 orig = opts;
668
669 while ((p = strsep(&opts, ",")) != NULL) {
670 int token;
671 if (!*p)
672 continue;
673
674 token = match_token(p, tokens, args);
675 switch (token) {
676 case Opt_subvol:
677 kfree(*subvol_name);
678 *subvol_name = match_strdup(&args[0]);
679 break;
680 case Opt_subvolid:
681 intarg = 0;
682 error = match_int(&args[0], &intarg);
683 if (!error) {
684 /* we want the original fs_tree */
685 if (!intarg)
686 *subvol_objectid =
687 BTRFS_FS_TREE_OBJECTID;
688 else
689 *subvol_objectid = intarg;
690 }
691 break;
692 case Opt_subvolrootid:
693 printk(KERN_WARNING
694 "btrfs: 'subvolrootid' mount option is deprecated and has no effect\n");
695 break;
696 case Opt_device:
697 device_name = match_strdup(&args[0]);
698 if (!device_name) {
699 error = -ENOMEM;
700 goto out;
701 }
702 error = btrfs_scan_one_device(device_name,
703 flags, holder, fs_devices);
704 kfree(device_name);
705 if (error)
706 goto out;
707 break;
708 default:
709 break;
710 }
711 }
712
713 out:
714 kfree(orig);
715 return error;
716 }
717
718 static struct dentry *get_default_root(struct super_block *sb,
719 u64 subvol_objectid)
720 {
721 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
722 struct btrfs_root *root = fs_info->tree_root;
723 struct btrfs_root *new_root;
724 struct btrfs_dir_item *di;
725 struct btrfs_path *path;
726 struct btrfs_key location;
727 struct inode *inode;
728 u64 dir_id;
729 int new = 0;
730
731 /*
732 * We have a specific subvol we want to mount, just setup location and
733 * go look up the root.
734 */
735 if (subvol_objectid) {
736 location.objectid = subvol_objectid;
737 location.type = BTRFS_ROOT_ITEM_KEY;
738 location.offset = (u64)-1;
739 goto find_root;
740 }
741
742 path = btrfs_alloc_path();
743 if (!path)
744 return ERR_PTR(-ENOMEM);
745 path->leave_spinning = 1;
746
747 /*
748 * Find the "default" dir item which points to the root item that we
749 * will mount by default if we haven't been given a specific subvolume
750 * to mount.
751 */
752 dir_id = btrfs_super_root_dir(fs_info->super_copy);
753 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
754 if (IS_ERR(di)) {
755 btrfs_free_path(path);
756 return ERR_CAST(di);
757 }
758 if (!di) {
759 /*
760 * Ok the default dir item isn't there. This is weird since
761 * it's always been there, but don't freak out, just try and
762 * mount to root most subvolume.
763 */
764 btrfs_free_path(path);
765 dir_id = BTRFS_FIRST_FREE_OBJECTID;
766 new_root = fs_info->fs_root;
767 goto setup_root;
768 }
769
770 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
771 btrfs_free_path(path);
772
773 find_root:
774 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
775 if (IS_ERR(new_root))
776 return ERR_CAST(new_root);
777
778 dir_id = btrfs_root_dirid(&new_root->root_item);
779 setup_root:
780 location.objectid = dir_id;
781 location.type = BTRFS_INODE_ITEM_KEY;
782 location.offset = 0;
783
784 inode = btrfs_iget(sb, &location, new_root, &new);
785 if (IS_ERR(inode))
786 return ERR_CAST(inode);
787
788 /*
789 * If we're just mounting the root most subvol put the inode and return
790 * a reference to the dentry. We will have already gotten a reference
791 * to the inode in btrfs_fill_super so we're good to go.
792 */
793 if (!new && sb->s_root->d_inode == inode) {
794 iput(inode);
795 return dget(sb->s_root);
796 }
797
798 return d_obtain_alias(inode);
799 }
800
801 static int btrfs_fill_super(struct super_block *sb,
802 struct btrfs_fs_devices *fs_devices,
803 void *data, int silent)
804 {
805 struct inode *inode;
806 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
807 struct btrfs_key key;
808 int err;
809
810 sb->s_maxbytes = MAX_LFS_FILESIZE;
811 sb->s_magic = BTRFS_SUPER_MAGIC;
812 sb->s_op = &btrfs_super_ops;
813 sb->s_d_op = &btrfs_dentry_operations;
814 sb->s_export_op = &btrfs_export_ops;
815 sb->s_xattr = btrfs_xattr_handlers;
816 sb->s_time_gran = 1;
817 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
818 sb->s_flags |= MS_POSIXACL;
819 #endif
820 sb->s_flags |= MS_I_VERSION;
821 err = open_ctree(sb, fs_devices, (char *)data);
822 if (err) {
823 printk("btrfs: open_ctree failed\n");
824 return err;
825 }
826
827 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
828 key.type = BTRFS_INODE_ITEM_KEY;
829 key.offset = 0;
830 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
831 if (IS_ERR(inode)) {
832 err = PTR_ERR(inode);
833 goto fail_close;
834 }
835
836 sb->s_root = d_make_root(inode);
837 if (!sb->s_root) {
838 err = -ENOMEM;
839 goto fail_close;
840 }
841
842 save_mount_options(sb, data);
843 cleancache_init_fs(sb);
844 sb->s_flags |= MS_ACTIVE;
845 return 0;
846
847 fail_close:
848 close_ctree(fs_info->tree_root);
849 return err;
850 }
851
852 int btrfs_sync_fs(struct super_block *sb, int wait)
853 {
854 struct btrfs_trans_handle *trans;
855 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
856 struct btrfs_root *root = fs_info->tree_root;
857
858 trace_btrfs_sync_fs(wait);
859
860 if (!wait) {
861 filemap_flush(fs_info->btree_inode->i_mapping);
862 return 0;
863 }
864
865 btrfs_wait_all_ordered_extents(fs_info, 0);
866
867 trans = btrfs_attach_transaction_barrier(root);
868 if (IS_ERR(trans)) {
869 /* no transaction, don't bother */
870 if (PTR_ERR(trans) == -ENOENT)
871 return 0;
872 return PTR_ERR(trans);
873 }
874 return btrfs_commit_transaction(trans, root);
875 }
876
877 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
878 {
879 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
880 struct btrfs_root *root = info->tree_root;
881 char *compress_type;
882
883 if (btrfs_test_opt(root, DEGRADED))
884 seq_puts(seq, ",degraded");
885 if (btrfs_test_opt(root, NODATASUM))
886 seq_puts(seq, ",nodatasum");
887 if (btrfs_test_opt(root, NODATACOW))
888 seq_puts(seq, ",nodatacow");
889 if (btrfs_test_opt(root, NOBARRIER))
890 seq_puts(seq, ",nobarrier");
891 if (info->max_inline != 8192 * 1024)
892 seq_printf(seq, ",max_inline=%llu",
893 (unsigned long long)info->max_inline);
894 if (info->alloc_start != 0)
895 seq_printf(seq, ",alloc_start=%llu",
896 (unsigned long long)info->alloc_start);
897 if (info->thread_pool_size != min_t(unsigned long,
898 num_online_cpus() + 2, 8))
899 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
900 if (btrfs_test_opt(root, COMPRESS)) {
901 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
902 compress_type = "zlib";
903 else
904 compress_type = "lzo";
905 if (btrfs_test_opt(root, FORCE_COMPRESS))
906 seq_printf(seq, ",compress-force=%s", compress_type);
907 else
908 seq_printf(seq, ",compress=%s", compress_type);
909 }
910 if (btrfs_test_opt(root, NOSSD))
911 seq_puts(seq, ",nossd");
912 if (btrfs_test_opt(root, SSD_SPREAD))
913 seq_puts(seq, ",ssd_spread");
914 else if (btrfs_test_opt(root, SSD))
915 seq_puts(seq, ",ssd");
916 if (btrfs_test_opt(root, NOTREELOG))
917 seq_puts(seq, ",notreelog");
918 if (btrfs_test_opt(root, FLUSHONCOMMIT))
919 seq_puts(seq, ",flushoncommit");
920 if (btrfs_test_opt(root, DISCARD))
921 seq_puts(seq, ",discard");
922 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
923 seq_puts(seq, ",noacl");
924 if (btrfs_test_opt(root, SPACE_CACHE))
925 seq_puts(seq, ",space_cache");
926 else
927 seq_puts(seq, ",nospace_cache");
928 if (btrfs_test_opt(root, CLEAR_CACHE))
929 seq_puts(seq, ",clear_cache");
930 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
931 seq_puts(seq, ",user_subvol_rm_allowed");
932 if (btrfs_test_opt(root, ENOSPC_DEBUG))
933 seq_puts(seq, ",enospc_debug");
934 if (btrfs_test_opt(root, AUTO_DEFRAG))
935 seq_puts(seq, ",autodefrag");
936 if (btrfs_test_opt(root, INODE_MAP_CACHE))
937 seq_puts(seq, ",inode_cache");
938 if (btrfs_test_opt(root, SKIP_BALANCE))
939 seq_puts(seq, ",skip_balance");
940 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
941 seq_puts(seq, ",fatal_errors=panic");
942 return 0;
943 }
944
945 static int btrfs_test_super(struct super_block *s, void *data)
946 {
947 struct btrfs_fs_info *p = data;
948 struct btrfs_fs_info *fs_info = btrfs_sb(s);
949
950 return fs_info->fs_devices == p->fs_devices;
951 }
952
953 static int btrfs_set_super(struct super_block *s, void *data)
954 {
955 int err = set_anon_super(s, data);
956 if (!err)
957 s->s_fs_info = data;
958 return err;
959 }
960
961 /*
962 * subvolumes are identified by ino 256
963 */
964 static inline int is_subvolume_inode(struct inode *inode)
965 {
966 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
967 return 1;
968 return 0;
969 }
970
971 /*
972 * This will strip out the subvol=%s argument for an argument string and add
973 * subvolid=0 to make sure we get the actual tree root for path walking to the
974 * subvol we want.
975 */
976 static char *setup_root_args(char *args)
977 {
978 unsigned len = strlen(args) + 2 + 1;
979 char *src, *dst, *buf;
980
981 /*
982 * We need the same args as before, but with this substitution:
983 * s!subvol=[^,]+!subvolid=0!
984 *
985 * Since the replacement string is up to 2 bytes longer than the
986 * original, allocate strlen(args) + 2 + 1 bytes.
987 */
988
989 src = strstr(args, "subvol=");
990 /* This shouldn't happen, but just in case.. */
991 if (!src)
992 return NULL;
993
994 buf = dst = kmalloc(len, GFP_NOFS);
995 if (!buf)
996 return NULL;
997
998 /*
999 * If the subvol= arg is not at the start of the string,
1000 * copy whatever precedes it into buf.
1001 */
1002 if (src != args) {
1003 *src++ = '\0';
1004 strcpy(buf, args);
1005 dst += strlen(args);
1006 }
1007
1008 strcpy(dst, "subvolid=0");
1009 dst += strlen("subvolid=0");
1010
1011 /*
1012 * If there is a "," after the original subvol=... string,
1013 * copy that suffix into our buffer. Otherwise, we're done.
1014 */
1015 src = strchr(src, ',');
1016 if (src)
1017 strcpy(dst, src);
1018
1019 return buf;
1020 }
1021
1022 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1023 const char *device_name, char *data)
1024 {
1025 struct dentry *root;
1026 struct vfsmount *mnt;
1027 char *newargs;
1028
1029 newargs = setup_root_args(data);
1030 if (!newargs)
1031 return ERR_PTR(-ENOMEM);
1032 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1033 newargs);
1034 kfree(newargs);
1035 if (IS_ERR(mnt))
1036 return ERR_CAST(mnt);
1037
1038 root = mount_subtree(mnt, subvol_name);
1039
1040 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1041 struct super_block *s = root->d_sb;
1042 dput(root);
1043 root = ERR_PTR(-EINVAL);
1044 deactivate_locked_super(s);
1045 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
1046 subvol_name);
1047 }
1048
1049 return root;
1050 }
1051
1052 /*
1053 * Find a superblock for the given device / mount point.
1054 *
1055 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1056 * for multiple device setup. Make sure to keep it in sync.
1057 */
1058 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1059 const char *device_name, void *data)
1060 {
1061 struct block_device *bdev = NULL;
1062 struct super_block *s;
1063 struct dentry *root;
1064 struct btrfs_fs_devices *fs_devices = NULL;
1065 struct btrfs_fs_info *fs_info = NULL;
1066 fmode_t mode = FMODE_READ;
1067 char *subvol_name = NULL;
1068 u64 subvol_objectid = 0;
1069 int error = 0;
1070
1071 if (!(flags & MS_RDONLY))
1072 mode |= FMODE_WRITE;
1073
1074 error = btrfs_parse_early_options(data, mode, fs_type,
1075 &subvol_name, &subvol_objectid,
1076 &fs_devices);
1077 if (error) {
1078 kfree(subvol_name);
1079 return ERR_PTR(error);
1080 }
1081
1082 if (subvol_name) {
1083 root = mount_subvol(subvol_name, flags, device_name, data);
1084 kfree(subvol_name);
1085 return root;
1086 }
1087
1088 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1089 if (error)
1090 return ERR_PTR(error);
1091
1092 /*
1093 * Setup a dummy root and fs_info for test/set super. This is because
1094 * we don't actually fill this stuff out until open_ctree, but we need
1095 * it for searching for existing supers, so this lets us do that and
1096 * then open_ctree will properly initialize everything later.
1097 */
1098 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1099 if (!fs_info)
1100 return ERR_PTR(-ENOMEM);
1101
1102 fs_info->fs_devices = fs_devices;
1103
1104 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1105 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1106 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1107 error = -ENOMEM;
1108 goto error_fs_info;
1109 }
1110
1111 error = btrfs_open_devices(fs_devices, mode, fs_type);
1112 if (error)
1113 goto error_fs_info;
1114
1115 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1116 error = -EACCES;
1117 goto error_close_devices;
1118 }
1119
1120 bdev = fs_devices->latest_bdev;
1121 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1122 fs_info);
1123 if (IS_ERR(s)) {
1124 error = PTR_ERR(s);
1125 goto error_close_devices;
1126 }
1127
1128 if (s->s_root) {
1129 btrfs_close_devices(fs_devices);
1130 free_fs_info(fs_info);
1131 if ((flags ^ s->s_flags) & MS_RDONLY)
1132 error = -EBUSY;
1133 } else {
1134 char b[BDEVNAME_SIZE];
1135
1136 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1137 btrfs_sb(s)->bdev_holder = fs_type;
1138 error = btrfs_fill_super(s, fs_devices, data,
1139 flags & MS_SILENT ? 1 : 0);
1140 }
1141
1142 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1143 if (IS_ERR(root))
1144 deactivate_locked_super(s);
1145
1146 return root;
1147
1148 error_close_devices:
1149 btrfs_close_devices(fs_devices);
1150 error_fs_info:
1151 free_fs_info(fs_info);
1152 return ERR_PTR(error);
1153 }
1154
1155 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1156 {
1157 spin_lock_irq(&workers->lock);
1158 workers->max_workers = new_limit;
1159 spin_unlock_irq(&workers->lock);
1160 }
1161
1162 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1163 int new_pool_size, int old_pool_size)
1164 {
1165 if (new_pool_size == old_pool_size)
1166 return;
1167
1168 fs_info->thread_pool_size = new_pool_size;
1169
1170 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1171 old_pool_size, new_pool_size);
1172
1173 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1174 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1175 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1176 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1177 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1178 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1179 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1180 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1181 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1182 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1183 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1184 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1185 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1186 btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1187 new_pool_size);
1188 }
1189
1190 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1191 {
1192 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1193 }
1194
1195 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1196 unsigned long old_opts, int flags)
1197 {
1198 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1199 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1200 (flags & MS_RDONLY))) {
1201 /* wait for any defraggers to finish */
1202 wait_event(fs_info->transaction_wait,
1203 (atomic_read(&fs_info->defrag_running) == 0));
1204 if (flags & MS_RDONLY)
1205 sync_filesystem(fs_info->sb);
1206 }
1207 }
1208
1209 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1210 unsigned long old_opts)
1211 {
1212 /*
1213 * We need cleanup all defragable inodes if the autodefragment is
1214 * close or the fs is R/O.
1215 */
1216 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1217 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1218 (fs_info->sb->s_flags & MS_RDONLY))) {
1219 btrfs_cleanup_defrag_inodes(fs_info);
1220 }
1221
1222 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1223 }
1224
1225 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1226 {
1227 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1228 struct btrfs_root *root = fs_info->tree_root;
1229 unsigned old_flags = sb->s_flags;
1230 unsigned long old_opts = fs_info->mount_opt;
1231 unsigned long old_compress_type = fs_info->compress_type;
1232 u64 old_max_inline = fs_info->max_inline;
1233 u64 old_alloc_start = fs_info->alloc_start;
1234 int old_thread_pool_size = fs_info->thread_pool_size;
1235 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1236 int ret;
1237
1238 btrfs_remount_prepare(fs_info);
1239
1240 ret = btrfs_parse_options(root, data);
1241 if (ret) {
1242 ret = -EINVAL;
1243 goto restore;
1244 }
1245
1246 btrfs_remount_begin(fs_info, old_opts, *flags);
1247 btrfs_resize_thread_pool(fs_info,
1248 fs_info->thread_pool_size, old_thread_pool_size);
1249
1250 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1251 goto out;
1252
1253 if (*flags & MS_RDONLY) {
1254 /*
1255 * this also happens on 'umount -rf' or on shutdown, when
1256 * the filesystem is busy.
1257 */
1258 sb->s_flags |= MS_RDONLY;
1259
1260 btrfs_dev_replace_suspend_for_unmount(fs_info);
1261 btrfs_scrub_cancel(fs_info);
1262 btrfs_pause_balance(fs_info);
1263
1264 ret = btrfs_commit_super(root);
1265 if (ret)
1266 goto restore;
1267 } else {
1268 if (fs_info->fs_devices->rw_devices == 0) {
1269 ret = -EACCES;
1270 goto restore;
1271 }
1272
1273 if (fs_info->fs_devices->missing_devices >
1274 fs_info->num_tolerated_disk_barrier_failures &&
1275 !(*flags & MS_RDONLY)) {
1276 printk(KERN_WARNING
1277 "Btrfs: too many missing devices, writeable remount is not allowed\n");
1278 ret = -EACCES;
1279 goto restore;
1280 }
1281
1282 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1283 ret = -EINVAL;
1284 goto restore;
1285 }
1286
1287 ret = btrfs_cleanup_fs_roots(fs_info);
1288 if (ret)
1289 goto restore;
1290
1291 /* recover relocation */
1292 ret = btrfs_recover_relocation(root);
1293 if (ret)
1294 goto restore;
1295
1296 ret = btrfs_resume_balance_async(fs_info);
1297 if (ret)
1298 goto restore;
1299
1300 ret = btrfs_resume_dev_replace_async(fs_info);
1301 if (ret) {
1302 pr_warn("btrfs: failed to resume dev_replace\n");
1303 goto restore;
1304 }
1305 sb->s_flags &= ~MS_RDONLY;
1306 }
1307 out:
1308 btrfs_remount_cleanup(fs_info, old_opts);
1309 return 0;
1310
1311 restore:
1312 /* We've hit an error - don't reset MS_RDONLY */
1313 if (sb->s_flags & MS_RDONLY)
1314 old_flags |= MS_RDONLY;
1315 sb->s_flags = old_flags;
1316 fs_info->mount_opt = old_opts;
1317 fs_info->compress_type = old_compress_type;
1318 fs_info->max_inline = old_max_inline;
1319 mutex_lock(&fs_info->chunk_mutex);
1320 fs_info->alloc_start = old_alloc_start;
1321 mutex_unlock(&fs_info->chunk_mutex);
1322 btrfs_resize_thread_pool(fs_info,
1323 old_thread_pool_size, fs_info->thread_pool_size);
1324 fs_info->metadata_ratio = old_metadata_ratio;
1325 btrfs_remount_cleanup(fs_info, old_opts);
1326 return ret;
1327 }
1328
1329 /* Used to sort the devices by max_avail(descending sort) */
1330 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1331 const void *dev_info2)
1332 {
1333 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1334 ((struct btrfs_device_info *)dev_info2)->max_avail)
1335 return -1;
1336 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1337 ((struct btrfs_device_info *)dev_info2)->max_avail)
1338 return 1;
1339 else
1340 return 0;
1341 }
1342
1343 /*
1344 * sort the devices by max_avail, in which max free extent size of each device
1345 * is stored.(Descending Sort)
1346 */
1347 static inline void btrfs_descending_sort_devices(
1348 struct btrfs_device_info *devices,
1349 size_t nr_devices)
1350 {
1351 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1352 btrfs_cmp_device_free_bytes, NULL);
1353 }
1354
1355 /*
1356 * The helper to calc the free space on the devices that can be used to store
1357 * file data.
1358 */
1359 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1360 {
1361 struct btrfs_fs_info *fs_info = root->fs_info;
1362 struct btrfs_device_info *devices_info;
1363 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1364 struct btrfs_device *device;
1365 u64 skip_space;
1366 u64 type;
1367 u64 avail_space;
1368 u64 used_space;
1369 u64 min_stripe_size;
1370 int min_stripes = 1, num_stripes = 1;
1371 int i = 0, nr_devices;
1372 int ret;
1373
1374 nr_devices = fs_info->fs_devices->open_devices;
1375 BUG_ON(!nr_devices);
1376
1377 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1378 GFP_NOFS);
1379 if (!devices_info)
1380 return -ENOMEM;
1381
1382 /* calc min stripe number for data space alloction */
1383 type = btrfs_get_alloc_profile(root, 1);
1384 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1385 min_stripes = 2;
1386 num_stripes = nr_devices;
1387 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1388 min_stripes = 2;
1389 num_stripes = 2;
1390 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1391 min_stripes = 4;
1392 num_stripes = 4;
1393 }
1394
1395 if (type & BTRFS_BLOCK_GROUP_DUP)
1396 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1397 else
1398 min_stripe_size = BTRFS_STRIPE_LEN;
1399
1400 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1401 if (!device->in_fs_metadata || !device->bdev ||
1402 device->is_tgtdev_for_dev_replace)
1403 continue;
1404
1405 avail_space = device->total_bytes - device->bytes_used;
1406
1407 /* align with stripe_len */
1408 do_div(avail_space, BTRFS_STRIPE_LEN);
1409 avail_space *= BTRFS_STRIPE_LEN;
1410
1411 /*
1412 * In order to avoid overwritting the superblock on the drive,
1413 * btrfs starts at an offset of at least 1MB when doing chunk
1414 * allocation.
1415 */
1416 skip_space = 1024 * 1024;
1417
1418 /* user can set the offset in fs_info->alloc_start. */
1419 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1420 device->total_bytes)
1421 skip_space = max(fs_info->alloc_start, skip_space);
1422
1423 /*
1424 * btrfs can not use the free space in [0, skip_space - 1],
1425 * we must subtract it from the total. In order to implement
1426 * it, we account the used space in this range first.
1427 */
1428 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1429 &used_space);
1430 if (ret) {
1431 kfree(devices_info);
1432 return ret;
1433 }
1434
1435 /* calc the free space in [0, skip_space - 1] */
1436 skip_space -= used_space;
1437
1438 /*
1439 * we can use the free space in [0, skip_space - 1], subtract
1440 * it from the total.
1441 */
1442 if (avail_space && avail_space >= skip_space)
1443 avail_space -= skip_space;
1444 else
1445 avail_space = 0;
1446
1447 if (avail_space < min_stripe_size)
1448 continue;
1449
1450 devices_info[i].dev = device;
1451 devices_info[i].max_avail = avail_space;
1452
1453 i++;
1454 }
1455
1456 nr_devices = i;
1457
1458 btrfs_descending_sort_devices(devices_info, nr_devices);
1459
1460 i = nr_devices - 1;
1461 avail_space = 0;
1462 while (nr_devices >= min_stripes) {
1463 if (num_stripes > nr_devices)
1464 num_stripes = nr_devices;
1465
1466 if (devices_info[i].max_avail >= min_stripe_size) {
1467 int j;
1468 u64 alloc_size;
1469
1470 avail_space += devices_info[i].max_avail * num_stripes;
1471 alloc_size = devices_info[i].max_avail;
1472 for (j = i + 1 - num_stripes; j <= i; j++)
1473 devices_info[j].max_avail -= alloc_size;
1474 }
1475 i--;
1476 nr_devices--;
1477 }
1478
1479 kfree(devices_info);
1480 *free_bytes = avail_space;
1481 return 0;
1482 }
1483
1484 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1485 {
1486 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1487 struct btrfs_super_block *disk_super = fs_info->super_copy;
1488 struct list_head *head = &fs_info->space_info;
1489 struct btrfs_space_info *found;
1490 u64 total_used = 0;
1491 u64 total_free_data = 0;
1492 int bits = dentry->d_sb->s_blocksize_bits;
1493 __be32 *fsid = (__be32 *)fs_info->fsid;
1494 int ret;
1495
1496 /* holding chunk_muext to avoid allocating new chunks */
1497 mutex_lock(&fs_info->chunk_mutex);
1498 rcu_read_lock();
1499 list_for_each_entry_rcu(found, head, list) {
1500 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1501 total_free_data += found->disk_total - found->disk_used;
1502 total_free_data -=
1503 btrfs_account_ro_block_groups_free_space(found);
1504 }
1505
1506 total_used += found->disk_used;
1507 }
1508 rcu_read_unlock();
1509
1510 buf->f_namelen = BTRFS_NAME_LEN;
1511 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1512 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1513 buf->f_bsize = dentry->d_sb->s_blocksize;
1514 buf->f_type = BTRFS_SUPER_MAGIC;
1515 buf->f_bavail = total_free_data;
1516 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1517 if (ret) {
1518 mutex_unlock(&fs_info->chunk_mutex);
1519 return ret;
1520 }
1521 buf->f_bavail += total_free_data;
1522 buf->f_bavail = buf->f_bavail >> bits;
1523 mutex_unlock(&fs_info->chunk_mutex);
1524
1525 /* We treat it as constant endianness (it doesn't matter _which_)
1526 because we want the fsid to come out the same whether mounted
1527 on a big-endian or little-endian host */
1528 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1529 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1530 /* Mask in the root object ID too, to disambiguate subvols */
1531 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1532 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1533
1534 return 0;
1535 }
1536
1537 static void btrfs_kill_super(struct super_block *sb)
1538 {
1539 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1540 kill_anon_super(sb);
1541 free_fs_info(fs_info);
1542 }
1543
1544 static struct file_system_type btrfs_fs_type = {
1545 .owner = THIS_MODULE,
1546 .name = "btrfs",
1547 .mount = btrfs_mount,
1548 .kill_sb = btrfs_kill_super,
1549 .fs_flags = FS_REQUIRES_DEV,
1550 };
1551 MODULE_ALIAS_FS("btrfs");
1552
1553 /*
1554 * used by btrfsctl to scan devices when no FS is mounted
1555 */
1556 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1557 unsigned long arg)
1558 {
1559 struct btrfs_ioctl_vol_args *vol;
1560 struct btrfs_fs_devices *fs_devices;
1561 int ret = -ENOTTY;
1562
1563 if (!capable(CAP_SYS_ADMIN))
1564 return -EPERM;
1565
1566 vol = memdup_user((void __user *)arg, sizeof(*vol));
1567 if (IS_ERR(vol))
1568 return PTR_ERR(vol);
1569
1570 switch (cmd) {
1571 case BTRFS_IOC_SCAN_DEV:
1572 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1573 &btrfs_fs_type, &fs_devices);
1574 break;
1575 case BTRFS_IOC_DEVICES_READY:
1576 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1577 &btrfs_fs_type, &fs_devices);
1578 if (ret)
1579 break;
1580 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1581 break;
1582 }
1583
1584 kfree(vol);
1585 return ret;
1586 }
1587
1588 static int btrfs_freeze(struct super_block *sb)
1589 {
1590 struct btrfs_trans_handle *trans;
1591 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1592
1593 trans = btrfs_attach_transaction_barrier(root);
1594 if (IS_ERR(trans)) {
1595 /* no transaction, don't bother */
1596 if (PTR_ERR(trans) == -ENOENT)
1597 return 0;
1598 return PTR_ERR(trans);
1599 }
1600 return btrfs_commit_transaction(trans, root);
1601 }
1602
1603 static int btrfs_unfreeze(struct super_block *sb)
1604 {
1605 return 0;
1606 }
1607
1608 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1609 {
1610 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1611 struct btrfs_fs_devices *cur_devices;
1612 struct btrfs_device *dev, *first_dev = NULL;
1613 struct list_head *head;
1614 struct rcu_string *name;
1615
1616 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1617 cur_devices = fs_info->fs_devices;
1618 while (cur_devices) {
1619 head = &cur_devices->devices;
1620 list_for_each_entry(dev, head, dev_list) {
1621 if (dev->missing)
1622 continue;
1623 if (!first_dev || dev->devid < first_dev->devid)
1624 first_dev = dev;
1625 }
1626 cur_devices = cur_devices->seed;
1627 }
1628
1629 if (first_dev) {
1630 rcu_read_lock();
1631 name = rcu_dereference(first_dev->name);
1632 seq_escape(m, name->str, " \t\n\\");
1633 rcu_read_unlock();
1634 } else {
1635 WARN_ON(1);
1636 }
1637 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1638 return 0;
1639 }
1640
1641 static const struct super_operations btrfs_super_ops = {
1642 .drop_inode = btrfs_drop_inode,
1643 .evict_inode = btrfs_evict_inode,
1644 .put_super = btrfs_put_super,
1645 .sync_fs = btrfs_sync_fs,
1646 .show_options = btrfs_show_options,
1647 .show_devname = btrfs_show_devname,
1648 .write_inode = btrfs_write_inode,
1649 .alloc_inode = btrfs_alloc_inode,
1650 .destroy_inode = btrfs_destroy_inode,
1651 .statfs = btrfs_statfs,
1652 .remount_fs = btrfs_remount,
1653 .freeze_fs = btrfs_freeze,
1654 .unfreeze_fs = btrfs_unfreeze,
1655 };
1656
1657 static const struct file_operations btrfs_ctl_fops = {
1658 .unlocked_ioctl = btrfs_control_ioctl,
1659 .compat_ioctl = btrfs_control_ioctl,
1660 .owner = THIS_MODULE,
1661 .llseek = noop_llseek,
1662 };
1663
1664 static struct miscdevice btrfs_misc = {
1665 .minor = BTRFS_MINOR,
1666 .name = "btrfs-control",
1667 .fops = &btrfs_ctl_fops
1668 };
1669
1670 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1671 MODULE_ALIAS("devname:btrfs-control");
1672
1673 static int btrfs_interface_init(void)
1674 {
1675 return misc_register(&btrfs_misc);
1676 }
1677
1678 static void btrfs_interface_exit(void)
1679 {
1680 if (misc_deregister(&btrfs_misc) < 0)
1681 printk(KERN_INFO "btrfs: misc_deregister failed for control device\n");
1682 }
1683
1684 static void btrfs_print_info(void)
1685 {
1686 printk(KERN_INFO "Btrfs loaded"
1687 #ifdef CONFIG_BTRFS_DEBUG
1688 ", debug=on"
1689 #endif
1690 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1691 ", integrity-checker=on"
1692 #endif
1693 "\n");
1694 }
1695
1696 static int __init init_btrfs_fs(void)
1697 {
1698 int err;
1699
1700 err = btrfs_init_sysfs();
1701 if (err)
1702 return err;
1703
1704 btrfs_init_compress();
1705
1706 err = btrfs_init_cachep();
1707 if (err)
1708 goto free_compress;
1709
1710 err = extent_io_init();
1711 if (err)
1712 goto free_cachep;
1713
1714 err = extent_map_init();
1715 if (err)
1716 goto free_extent_io;
1717
1718 err = ordered_data_init();
1719 if (err)
1720 goto free_extent_map;
1721
1722 err = btrfs_delayed_inode_init();
1723 if (err)
1724 goto free_ordered_data;
1725
1726 err = btrfs_auto_defrag_init();
1727 if (err)
1728 goto free_delayed_inode;
1729
1730 err = btrfs_delayed_ref_init();
1731 if (err)
1732 goto free_auto_defrag;
1733
1734 err = btrfs_interface_init();
1735 if (err)
1736 goto free_delayed_ref;
1737
1738 err = register_filesystem(&btrfs_fs_type);
1739 if (err)
1740 goto unregister_ioctl;
1741
1742 btrfs_init_lockdep();
1743
1744 btrfs_print_info();
1745 btrfs_test_free_space_cache();
1746
1747 return 0;
1748
1749 unregister_ioctl:
1750 btrfs_interface_exit();
1751 free_delayed_ref:
1752 btrfs_delayed_ref_exit();
1753 free_auto_defrag:
1754 btrfs_auto_defrag_exit();
1755 free_delayed_inode:
1756 btrfs_delayed_inode_exit();
1757 free_ordered_data:
1758 ordered_data_exit();
1759 free_extent_map:
1760 extent_map_exit();
1761 free_extent_io:
1762 extent_io_exit();
1763 free_cachep:
1764 btrfs_destroy_cachep();
1765 free_compress:
1766 btrfs_exit_compress();
1767 btrfs_exit_sysfs();
1768 return err;
1769 }
1770
1771 static void __exit exit_btrfs_fs(void)
1772 {
1773 btrfs_destroy_cachep();
1774 btrfs_delayed_ref_exit();
1775 btrfs_auto_defrag_exit();
1776 btrfs_delayed_inode_exit();
1777 ordered_data_exit();
1778 extent_map_exit();
1779 extent_io_exit();
1780 btrfs_interface_exit();
1781 unregister_filesystem(&btrfs_fs_type);
1782 btrfs_exit_sysfs();
1783 btrfs_cleanup_fs_uuids();
1784 btrfs_exit_compress();
1785 }
1786
1787 module_init(init_btrfs_fs)
1788 module_exit(exit_btrfs_fs)
1789
1790 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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