?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
[linux-2.6/cjktty.git] / fs / btrfs / super.c
blobf6b88595f858b08f47fd530f3409124c288eb852
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 "version.h"
55 #include "export.h"
56 #include "compression.h"
57 #include "rcu-string.h"
58 #include "dev-replace.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, char nbuf[16])
67 {
68 char *errstr = NULL;
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 default:
84 if (nbuf) {
85 if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
86 errstr = nbuf;
87 }
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 static void save_error_info(struct btrfs_fs_info *fs_info)
104 {
105 __save_error_info(fs_info);
106 }
107
108 /* btrfs handle error by forcing the filesystem readonly */
109 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
110 {
111 struct super_block *sb = fs_info->sb;
112
113 if (sb->s_flags & MS_RDONLY)
114 return;
115
116 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
117 sb->s_flags |= MS_RDONLY;
118 printk(KERN_INFO "btrfs is forced readonly\n");
119 /*
120 * Note that a running device replace operation is not
121 * canceled here although there is no way to update
122 * the progress. It would add the risk of a deadlock,
123 * therefore the canceling is ommited. The only penalty
124 * is that some I/O remains active until the procedure
125 * completes. The next time when the filesystem is
126 * mounted writeable again, the device replace
127 * operation continues.
128 */
129 // WARN_ON(1);
130 }
131 }
132
133 #ifdef CONFIG_PRINTK
134 /*
135 * __btrfs_std_error decodes expected errors from the caller and
136 * invokes the approciate error response.
137 */
138 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
139 unsigned int line, int errno, const char *fmt, ...)
140 {
141 struct super_block *sb = fs_info->sb;
142 char nbuf[16];
143 const char *errstr;
144
145 /*
146 * Special case: if the error is EROFS, and we're already
147 * under MS_RDONLY, then it is safe here.
148 */
149 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
150 return;
151
152 errstr = btrfs_decode_error(errno, nbuf);
153 if (fmt) {
154 struct va_format vaf;
155 va_list args;
156
157 va_start(args, fmt);
158 vaf.fmt = fmt;
159 vaf.va = &args;
160
161 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s (%pV)\n",
162 sb->s_id, function, line, errstr, &vaf);
163 va_end(args);
164 } else {
165 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
166 sb->s_id, function, line, errstr);
167 }
168
169 /* Don't go through full error handling during mount */
170 if (sb->s_flags & MS_BORN) {
171 save_error_info(fs_info);
172 btrfs_handle_error(fs_info);
173 }
174 }
175
176 static const char * const logtypes[] = {
177 "emergency",
178 "alert",
179 "critical",
180 "error",
181 "warning",
182 "notice",
183 "info",
184 "debug",
185 };
186
187 void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...)
188 {
189 struct super_block *sb = fs_info->sb;
190 char lvl[4];
191 struct va_format vaf;
192 va_list args;
193 const char *type = logtypes[4];
194 int kern_level;
195
196 va_start(args, fmt);
197
198 kern_level = printk_get_level(fmt);
199 if (kern_level) {
200 size_t size = printk_skip_level(fmt) - fmt;
201 memcpy(lvl, fmt, size);
202 lvl[size] = '\0';
203 fmt += size;
204 type = logtypes[kern_level - '0'];
205 } else
206 *lvl = '\0';
207
208 vaf.fmt = fmt;
209 vaf.va = &args;
210
211 printk("%sBTRFS %s (device %s): %pV", lvl, type, sb->s_id, &vaf);
212
213 va_end(args);
214 }
215
216 #else
217
218 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
219 unsigned int line, int errno, const char *fmt, ...)
220 {
221 struct super_block *sb = fs_info->sb;
222
223 /*
224 * Special case: if the error is EROFS, and we're already
225 * under MS_RDONLY, then it is safe here.
226 */
227 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
228 return;
229
230 /* Don't go through full error handling during mount */
231 if (sb->s_flags & MS_BORN) {
232 save_error_info(fs_info);
233 btrfs_handle_error(fs_info);
234 }
235 }
236 #endif
237
238 /*
239 * We only mark the transaction aborted and then set the file system read-only.
240 * This will prevent new transactions from starting or trying to join this
241 * one.
242 *
243 * This means that error recovery at the call site is limited to freeing
244 * any local memory allocations and passing the error code up without
245 * further cleanup. The transaction should complete as it normally would
246 * in the call path but will return -EIO.
247 *
248 * We'll complete the cleanup in btrfs_end_transaction and
249 * btrfs_commit_transaction.
250 */
251 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
252 struct btrfs_root *root, const char *function,
253 unsigned int line, int errno)
254 {
255 WARN_ONCE(1, KERN_DEBUG "btrfs: Transaction aborted\n");
256 trans->aborted = errno;
257 /* Nothing used. The other threads that have joined this
258 * transaction may be able to continue. */
259 if (!trans->blocks_used) {
260 char nbuf[16];
261 const char *errstr;
262
263 errstr = btrfs_decode_error(errno, nbuf);
264 btrfs_printk(root->fs_info,
265 "%s:%d: Aborting unused transaction(%s).\n",
266 function, line, errstr);
267 return;
268 }
269 ACCESS_ONCE(trans->transaction->aborted) = errno;
270 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
271 }
272 /*
273 * __btrfs_panic decodes unexpected, fatal errors from the caller,
274 * issues an alert, and either panics or BUGs, depending on mount options.
275 */
276 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
277 unsigned int line, int errno, const char *fmt, ...)
278 {
279 char nbuf[16];
280 char *s_id = "<unknown>";
281 const char *errstr;
282 struct va_format vaf = { .fmt = fmt };
283 va_list args;
284
285 if (fs_info)
286 s_id = fs_info->sb->s_id;
287
288 va_start(args, fmt);
289 vaf.va = &args;
290
291 errstr = btrfs_decode_error(errno, nbuf);
292 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
293 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
294 s_id, function, line, &vaf, errstr);
295
296 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
297 s_id, function, line, &vaf, errstr);
298 va_end(args);
299 /* Caller calls BUG() */
300 }
301
302 static void btrfs_put_super(struct super_block *sb)
303 {
304 (void)close_ctree(btrfs_sb(sb)->tree_root);
305 /* FIXME: need to fix VFS to return error? */
306 /* AV: return it _where_? ->put_super() can be triggered by any number
307 * of async events, up to and including delivery of SIGKILL to the
308 * last process that kept it busy. Or segfault in the aforementioned
309 * process... Whom would you report that to?
310 */
311 }
312
313 enum {
314 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
315 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
316 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
317 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
318 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
319 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
320 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
321 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
322 Opt_check_integrity, Opt_check_integrity_including_extent_data,
323 Opt_check_integrity_print_mask, Opt_fatal_errors,
324 Opt_err,
325 };
326
327 static match_table_t tokens = {
328 {Opt_degraded, "degraded"},
329 {Opt_subvol, "subvol=%s"},
330 {Opt_subvolid, "subvolid=%d"},
331 {Opt_device, "device=%s"},
332 {Opt_nodatasum, "nodatasum"},
333 {Opt_nodatacow, "nodatacow"},
334 {Opt_nobarrier, "nobarrier"},
335 {Opt_max_inline, "max_inline=%s"},
336 {Opt_alloc_start, "alloc_start=%s"},
337 {Opt_thread_pool, "thread_pool=%d"},
338 {Opt_compress, "compress"},
339 {Opt_compress_type, "compress=%s"},
340 {Opt_compress_force, "compress-force"},
341 {Opt_compress_force_type, "compress-force=%s"},
342 {Opt_ssd, "ssd"},
343 {Opt_ssd_spread, "ssd_spread"},
344 {Opt_nossd, "nossd"},
345 {Opt_noacl, "noacl"},
346 {Opt_notreelog, "notreelog"},
347 {Opt_flushoncommit, "flushoncommit"},
348 {Opt_ratio, "metadata_ratio=%d"},
349 {Opt_discard, "discard"},
350 {Opt_space_cache, "space_cache"},
351 {Opt_clear_cache, "clear_cache"},
352 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
353 {Opt_enospc_debug, "enospc_debug"},
354 {Opt_subvolrootid, "subvolrootid=%d"},
355 {Opt_defrag, "autodefrag"},
356 {Opt_inode_cache, "inode_cache"},
357 {Opt_no_space_cache, "nospace_cache"},
358 {Opt_recovery, "recovery"},
359 {Opt_skip_balance, "skip_balance"},
360 {Opt_check_integrity, "check_int"},
361 {Opt_check_integrity_including_extent_data, "check_int_data"},
362 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
363 {Opt_fatal_errors, "fatal_errors=%s"},
364 {Opt_err, NULL},
365 };
366
367 /*
368 * Regular mount options parser. Everything that is needed only when
369 * reading in a new superblock is parsed here.
370 * XXX JDM: This needs to be cleaned up for remount.
371 */
372 int btrfs_parse_options(struct btrfs_root *root, char *options)
373 {
374 struct btrfs_fs_info *info = root->fs_info;
375 substring_t args[MAX_OPT_ARGS];
376 char *p, *num, *orig = NULL;
377 u64 cache_gen;
378 int intarg;
379 int ret = 0;
380 char *compress_type;
381 bool compress_force = false;
382
383 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
384 if (cache_gen)
385 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
386
387 if (!options)
388 goto out;
389
390 /*
391 * strsep changes the string, duplicate it because parse_options
392 * gets called twice
393 */
394 options = kstrdup(options, GFP_NOFS);
395 if (!options)
396 return -ENOMEM;
397
398 orig = options;
399
400 while ((p = strsep(&options, ",")) != NULL) {
401 int token;
402 if (!*p)
403 continue;
404
405 token = match_token(p, tokens, args);
406 switch (token) {
407 case Opt_degraded:
408 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
409 btrfs_set_opt(info->mount_opt, DEGRADED);
410 break;
411 case Opt_subvol:
412 case Opt_subvolid:
413 case Opt_subvolrootid:
414 case Opt_device:
415 /*
416 * These are parsed by btrfs_parse_early_options
417 * and can be happily ignored here.
418 */
419 break;
420 case Opt_nodatasum:
421 printk(KERN_INFO "btrfs: setting nodatasum\n");
422 btrfs_set_opt(info->mount_opt, NODATASUM);
423 break;
424 case Opt_nodatacow:
425 if (!btrfs_test_opt(root, COMPRESS) ||
426 !btrfs_test_opt(root, FORCE_COMPRESS)) {
427 printk(KERN_INFO "btrfs: setting nodatacow, compression disabled\n");
428 } else {
429 printk(KERN_INFO "btrfs: setting nodatacow\n");
430 }
431 info->compress_type = BTRFS_COMPRESS_NONE;
432 btrfs_clear_opt(info->mount_opt, COMPRESS);
433 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
434 btrfs_set_opt(info->mount_opt, NODATACOW);
435 btrfs_set_opt(info->mount_opt, NODATASUM);
436 break;
437 case Opt_compress_force:
438 case Opt_compress_force_type:
439 compress_force = true;
440 /* Fallthrough */
441 case Opt_compress:
442 case Opt_compress_type:
443 if (token == Opt_compress ||
444 token == Opt_compress_force ||
445 strcmp(args[0].from, "zlib") == 0) {
446 compress_type = "zlib";
447 info->compress_type = BTRFS_COMPRESS_ZLIB;
448 btrfs_set_opt(info->mount_opt, COMPRESS);
449 btrfs_clear_opt(info->mount_opt, NODATACOW);
450 btrfs_clear_opt(info->mount_opt, NODATASUM);
451 } else if (strcmp(args[0].from, "lzo") == 0) {
452 compress_type = "lzo";
453 info->compress_type = BTRFS_COMPRESS_LZO;
454 btrfs_set_opt(info->mount_opt, COMPRESS);
455 btrfs_clear_opt(info->mount_opt, NODATACOW);
456 btrfs_clear_opt(info->mount_opt, NODATASUM);
457 btrfs_set_fs_incompat(info, COMPRESS_LZO);
458 } else if (strncmp(args[0].from, "no", 2) == 0) {
459 compress_type = "no";
460 info->compress_type = BTRFS_COMPRESS_NONE;
461 btrfs_clear_opt(info->mount_opt, COMPRESS);
462 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
463 compress_force = false;
464 } else {
465 ret = -EINVAL;
466 goto out;
467 }
468
469 if (compress_force) {
470 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
471 pr_info("btrfs: force %s compression\n",
472 compress_type);
473 } else
474 pr_info("btrfs: use %s compression\n",
475 compress_type);
476 break;
477 case Opt_ssd:
478 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
479 btrfs_set_opt(info->mount_opt, SSD);
480 break;
481 case Opt_ssd_spread:
482 printk(KERN_INFO "btrfs: use spread ssd "
483 "allocation scheme\n");
484 btrfs_set_opt(info->mount_opt, SSD);
485 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
486 break;
487 case Opt_nossd:
488 printk(KERN_INFO "btrfs: not using ssd allocation "
489 "scheme\n");
490 btrfs_set_opt(info->mount_opt, NOSSD);
491 btrfs_clear_opt(info->mount_opt, SSD);
492 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
493 break;
494 case Opt_nobarrier:
495 printk(KERN_INFO "btrfs: turning off barriers\n");
496 btrfs_set_opt(info->mount_opt, NOBARRIER);
497 break;
498 case Opt_thread_pool:
499 intarg = 0;
500 match_int(&args[0], &intarg);
501 if (intarg)
502 info->thread_pool_size = intarg;
503 break;
504 case Opt_max_inline:
505 num = match_strdup(&args[0]);
506 if (num) {
507 info->max_inline = memparse(num, NULL);
508 kfree(num);
509
510 if (info->max_inline) {
511 info->max_inline = max_t(u64,
512 info->max_inline,
513 root->sectorsize);
514 }
515 printk(KERN_INFO "btrfs: max_inline at %llu\n",
516 (unsigned long long)info->max_inline);
517 }
518 break;
519 case Opt_alloc_start:
520 num = match_strdup(&args[0]);
521 if (num) {
522 mutex_lock(&info->chunk_mutex);
523 info->alloc_start = memparse(num, NULL);
524 mutex_unlock(&info->chunk_mutex);
525 kfree(num);
526 printk(KERN_INFO
527 "btrfs: allocations start at %llu\n",
528 (unsigned long long)info->alloc_start);
529 }
530 break;
531 case Opt_noacl:
532 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
533 break;
534 case Opt_notreelog:
535 printk(KERN_INFO "btrfs: disabling tree log\n");
536 btrfs_set_opt(info->mount_opt, NOTREELOG);
537 break;
538 case Opt_flushoncommit:
539 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
540 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
541 break;
542 case Opt_ratio:
543 intarg = 0;
544 match_int(&args[0], &intarg);
545 if (intarg) {
546 info->metadata_ratio = intarg;
547 printk(KERN_INFO "btrfs: metadata ratio %d\n",
548 info->metadata_ratio);
549 }
550 break;
551 case Opt_discard:
552 btrfs_set_opt(info->mount_opt, DISCARD);
553 break;
554 case Opt_space_cache:
555 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
556 break;
557 case Opt_no_space_cache:
558 printk(KERN_INFO "btrfs: disabling disk space caching\n");
559 btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
560 break;
561 case Opt_inode_cache:
562 printk(KERN_INFO "btrfs: enabling inode map caching\n");
563 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
564 break;
565 case Opt_clear_cache:
566 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
567 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
568 break;
569 case Opt_user_subvol_rm_allowed:
570 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
571 break;
572 case Opt_enospc_debug:
573 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
574 break;
575 case Opt_defrag:
576 printk(KERN_INFO "btrfs: enabling auto defrag\n");
577 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
578 break;
579 case Opt_recovery:
580 printk(KERN_INFO "btrfs: enabling auto recovery\n");
581 btrfs_set_opt(info->mount_opt, RECOVERY);
582 break;
583 case Opt_skip_balance:
584 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
585 break;
586 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
587 case Opt_check_integrity_including_extent_data:
588 printk(KERN_INFO "btrfs: enabling check integrity"
589 " including extent data\n");
590 btrfs_set_opt(info->mount_opt,
591 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
592 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
593 break;
594 case Opt_check_integrity:
595 printk(KERN_INFO "btrfs: enabling check integrity\n");
596 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
597 break;
598 case Opt_check_integrity_print_mask:
599 intarg = 0;
600 match_int(&args[0], &intarg);
601 if (intarg) {
602 info->check_integrity_print_mask = intarg;
603 printk(KERN_INFO "btrfs:"
604 " check_integrity_print_mask 0x%x\n",
605 info->check_integrity_print_mask);
606 }
607 break;
608 #else
609 case Opt_check_integrity_including_extent_data:
610 case Opt_check_integrity:
611 case Opt_check_integrity_print_mask:
612 printk(KERN_ERR "btrfs: support for check_integrity*"
613 " not compiled in!\n");
614 ret = -EINVAL;
615 goto out;
616 #endif
617 case Opt_fatal_errors:
618 if (strcmp(args[0].from, "panic") == 0)
619 btrfs_set_opt(info->mount_opt,
620 PANIC_ON_FATAL_ERROR);
621 else if (strcmp(args[0].from, "bug") == 0)
622 btrfs_clear_opt(info->mount_opt,
623 PANIC_ON_FATAL_ERROR);
624 else {
625 ret = -EINVAL;
626 goto out;
627 }
628 break;
629 case Opt_err:
630 printk(KERN_INFO "btrfs: unrecognized mount option "
631 "'%s'\n", p);
632 ret = -EINVAL;
633 goto out;
634 default:
635 break;
636 }
637 }
638 out:
639 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
640 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
641 kfree(orig);
642 return ret;
643 }
644
645 /*
646 * Parse mount options that are required early in the mount process.
647 *
648 * All other options will be parsed on much later in the mount process and
649 * only when we need to allocate a new super block.
650 */
651 static int btrfs_parse_early_options(const char *options, fmode_t flags,
652 void *holder, char **subvol_name, u64 *subvol_objectid,
653 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
654 {
655 substring_t args[MAX_OPT_ARGS];
656 char *device_name, *opts, *orig, *p;
657 int error = 0;
658 int intarg;
659
660 if (!options)
661 return 0;
662
663 /*
664 * strsep changes the string, duplicate it because parse_options
665 * gets called twice
666 */
667 opts = kstrdup(options, GFP_KERNEL);
668 if (!opts)
669 return -ENOMEM;
670 orig = opts;
671
672 while ((p = strsep(&opts, ",")) != NULL) {
673 int token;
674 if (!*p)
675 continue;
676
677 token = match_token(p, tokens, args);
678 switch (token) {
679 case Opt_subvol:
680 kfree(*subvol_name);
681 *subvol_name = match_strdup(&args[0]);
682 break;
683 case Opt_subvolid:
684 intarg = 0;
685 error = match_int(&args[0], &intarg);
686 if (!error) {
687 /* we want the original fs_tree */
688 if (!intarg)
689 *subvol_objectid =
690 BTRFS_FS_TREE_OBJECTID;
691 else
692 *subvol_objectid = intarg;
693 }
694 break;
695 case Opt_subvolrootid:
696 intarg = 0;
697 error = match_int(&args[0], &intarg);
698 if (!error) {
699 /* we want the original fs_tree */
700 if (!intarg)
701 *subvol_rootid =
702 BTRFS_FS_TREE_OBJECTID;
703 else
704 *subvol_rootid = intarg;
705 }
706 break;
707 case Opt_device:
708 device_name = match_strdup(&args[0]);
709 if (!device_name) {
710 error = -ENOMEM;
711 goto out;
712 }
713 error = btrfs_scan_one_device(device_name,
714 flags, holder, fs_devices);
715 kfree(device_name);
716 if (error)
717 goto out;
718 break;
719 default:
720 break;
721 }
722 }
723
724 out:
725 kfree(orig);
726 return error;
727 }
728
729 static struct dentry *get_default_root(struct super_block *sb,
730 u64 subvol_objectid)
731 {
732 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
733 struct btrfs_root *root = fs_info->tree_root;
734 struct btrfs_root *new_root;
735 struct btrfs_dir_item *di;
736 struct btrfs_path *path;
737 struct btrfs_key location;
738 struct inode *inode;
739 u64 dir_id;
740 int new = 0;
741
742 /*
743 * We have a specific subvol we want to mount, just setup location and
744 * go look up the root.
745 */
746 if (subvol_objectid) {
747 location.objectid = subvol_objectid;
748 location.type = BTRFS_ROOT_ITEM_KEY;
749 location.offset = (u64)-1;
750 goto find_root;
751 }
752
753 path = btrfs_alloc_path();
754 if (!path)
755 return ERR_PTR(-ENOMEM);
756 path->leave_spinning = 1;
757
758 /*
759 * Find the "default" dir item which points to the root item that we
760 * will mount by default if we haven't been given a specific subvolume
761 * to mount.
762 */
763 dir_id = btrfs_super_root_dir(fs_info->super_copy);
764 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
765 if (IS_ERR(di)) {
766 btrfs_free_path(path);
767 return ERR_CAST(di);
768 }
769 if (!di) {
770 /*
771 * Ok the default dir item isn't there. This is weird since
772 * it's always been there, but don't freak out, just try and
773 * mount to root most subvolume.
774 */
775 btrfs_free_path(path);
776 dir_id = BTRFS_FIRST_FREE_OBJECTID;
777 new_root = fs_info->fs_root;
778 goto setup_root;
779 }
780
781 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
782 btrfs_free_path(path);
783
784 find_root:
785 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
786 if (IS_ERR(new_root))
787 return ERR_CAST(new_root);
788
789 if (btrfs_root_refs(&new_root->root_item) == 0)
790 return ERR_PTR(-ENOENT);
791
792 dir_id = btrfs_root_dirid(&new_root->root_item);
793 setup_root:
794 location.objectid = dir_id;
795 location.type = BTRFS_INODE_ITEM_KEY;
796 location.offset = 0;
797
798 inode = btrfs_iget(sb, &location, new_root, &new);
799 if (IS_ERR(inode))
800 return ERR_CAST(inode);
801
802 /*
803 * If we're just mounting the root most subvol put the inode and return
804 * a reference to the dentry. We will have already gotten a reference
805 * to the inode in btrfs_fill_super so we're good to go.
806 */
807 if (!new && sb->s_root->d_inode == inode) {
808 iput(inode);
809 return dget(sb->s_root);
810 }
811
812 return d_obtain_alias(inode);
813 }
814
815 static int btrfs_fill_super(struct super_block *sb,
816 struct btrfs_fs_devices *fs_devices,
817 void *data, int silent)
818 {
819 struct inode *inode;
820 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
821 struct btrfs_key key;
822 int err;
823
824 sb->s_maxbytes = MAX_LFS_FILESIZE;
825 sb->s_magic = BTRFS_SUPER_MAGIC;
826 sb->s_op = &btrfs_super_ops;
827 sb->s_d_op = &btrfs_dentry_operations;
828 sb->s_export_op = &btrfs_export_ops;
829 sb->s_xattr = btrfs_xattr_handlers;
830 sb->s_time_gran = 1;
831 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
832 sb->s_flags |= MS_POSIXACL;
833 #endif
834 sb->s_flags |= MS_I_VERSION;
835 err = open_ctree(sb, fs_devices, (char *)data);
836 if (err) {
837 printk("btrfs: open_ctree failed\n");
838 return err;
839 }
840
841 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
842 key.type = BTRFS_INODE_ITEM_KEY;
843 key.offset = 0;
844 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
845 if (IS_ERR(inode)) {
846 err = PTR_ERR(inode);
847 goto fail_close;
848 }
849
850 sb->s_root = d_make_root(inode);
851 if (!sb->s_root) {
852 err = -ENOMEM;
853 goto fail_close;
854 }
855
856 save_mount_options(sb, data);
857 cleancache_init_fs(sb);
858 sb->s_flags |= MS_ACTIVE;
859 return 0;
860
861 fail_close:
862 close_ctree(fs_info->tree_root);
863 return err;
864 }
865
866 int btrfs_sync_fs(struct super_block *sb, int wait)
867 {
868 struct btrfs_trans_handle *trans;
869 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
870 struct btrfs_root *root = fs_info->tree_root;
871
872 trace_btrfs_sync_fs(wait);
873
874 if (!wait) {
875 filemap_flush(fs_info->btree_inode->i_mapping);
876 return 0;
877 }
878
879 btrfs_wait_ordered_extents(root, 0);
880
881 trans = btrfs_attach_transaction_barrier(root);
882 if (IS_ERR(trans)) {
883 /* no transaction, don't bother */
884 if (PTR_ERR(trans) == -ENOENT)
885 return 0;
886 return PTR_ERR(trans);
887 }
888 return btrfs_commit_transaction(trans, root);
889 }
890
891 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
892 {
893 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
894 struct btrfs_root *root = info->tree_root;
895 char *compress_type;
896
897 if (btrfs_test_opt(root, DEGRADED))
898 seq_puts(seq, ",degraded");
899 if (btrfs_test_opt(root, NODATASUM))
900 seq_puts(seq, ",nodatasum");
901 if (btrfs_test_opt(root, NODATACOW))
902 seq_puts(seq, ",nodatacow");
903 if (btrfs_test_opt(root, NOBARRIER))
904 seq_puts(seq, ",nobarrier");
905 if (info->max_inline != 8192 * 1024)
906 seq_printf(seq, ",max_inline=%llu",
907 (unsigned long long)info->max_inline);
908 if (info->alloc_start != 0)
909 seq_printf(seq, ",alloc_start=%llu",
910 (unsigned long long)info->alloc_start);
911 if (info->thread_pool_size != min_t(unsigned long,
912 num_online_cpus() + 2, 8))
913 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
914 if (btrfs_test_opt(root, COMPRESS)) {
915 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
916 compress_type = "zlib";
917 else
918 compress_type = "lzo";
919 if (btrfs_test_opt(root, FORCE_COMPRESS))
920 seq_printf(seq, ",compress-force=%s", compress_type);
921 else
922 seq_printf(seq, ",compress=%s", compress_type);
923 }
924 if (btrfs_test_opt(root, NOSSD))
925 seq_puts(seq, ",nossd");
926 if (btrfs_test_opt(root, SSD_SPREAD))
927 seq_puts(seq, ",ssd_spread");
928 else if (btrfs_test_opt(root, SSD))
929 seq_puts(seq, ",ssd");
930 if (btrfs_test_opt(root, NOTREELOG))
931 seq_puts(seq, ",notreelog");
932 if (btrfs_test_opt(root, FLUSHONCOMMIT))
933 seq_puts(seq, ",flushoncommit");
934 if (btrfs_test_opt(root, DISCARD))
935 seq_puts(seq, ",discard");
936 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
937 seq_puts(seq, ",noacl");
938 if (btrfs_test_opt(root, SPACE_CACHE))
939 seq_puts(seq, ",space_cache");
940 else
941 seq_puts(seq, ",nospace_cache");
942 if (btrfs_test_opt(root, CLEAR_CACHE))
943 seq_puts(seq, ",clear_cache");
944 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
945 seq_puts(seq, ",user_subvol_rm_allowed");
946 if (btrfs_test_opt(root, ENOSPC_DEBUG))
947 seq_puts(seq, ",enospc_debug");
948 if (btrfs_test_opt(root, AUTO_DEFRAG))
949 seq_puts(seq, ",autodefrag");
950 if (btrfs_test_opt(root, INODE_MAP_CACHE))
951 seq_puts(seq, ",inode_cache");
952 if (btrfs_test_opt(root, SKIP_BALANCE))
953 seq_puts(seq, ",skip_balance");
954 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
955 seq_puts(seq, ",fatal_errors=panic");
956 return 0;
957 }
958
959 static int btrfs_test_super(struct super_block *s, void *data)
960 {
961 struct btrfs_fs_info *p = data;
962 struct btrfs_fs_info *fs_info = btrfs_sb(s);
963
964 return fs_info->fs_devices == p->fs_devices;
965 }
966
967 static int btrfs_set_super(struct super_block *s, void *data)
968 {
969 int err = set_anon_super(s, data);
970 if (!err)
971 s->s_fs_info = data;
972 return err;
973 }
974
975 /*
976 * subvolumes are identified by ino 256
977 */
978 static inline int is_subvolume_inode(struct inode *inode)
979 {
980 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
981 return 1;
982 return 0;
983 }
984
985 /*
986 * This will strip out the subvol=%s argument for an argument string and add
987 * subvolid=0 to make sure we get the actual tree root for path walking to the
988 * subvol we want.
989 */
990 static char *setup_root_args(char *args)
991 {
992 unsigned len = strlen(args) + 2 + 1;
993 char *src, *dst, *buf;
994
995 /*
996 * We need the same args as before, but with this substitution:
997 * s!subvol=[^,]+!subvolid=0!
998 *
999 * Since the replacement string is up to 2 bytes longer than the
1000 * original, allocate strlen(args) + 2 + 1 bytes.
1001 */
1002
1003 src = strstr(args, "subvol=");
1004 /* This shouldn't happen, but just in case.. */
1005 if (!src)
1006 return NULL;
1007
1008 buf = dst = kmalloc(len, GFP_NOFS);
1009 if (!buf)
1010 return NULL;
1011
1012 /*
1013 * If the subvol= arg is not at the start of the string,
1014 * copy whatever precedes it into buf.
1015 */
1016 if (src != args) {
1017 *src++ = '\0';
1018 strcpy(buf, args);
1019 dst += strlen(args);
1020 }
1021
1022 strcpy(dst, "subvolid=0");
1023 dst += strlen("subvolid=0");
1024
1025 /*
1026 * If there is a "," after the original subvol=... string,
1027 * copy that suffix into our buffer. Otherwise, we're done.
1028 */
1029 src = strchr(src, ',');
1030 if (src)
1031 strcpy(dst, src);
1032
1033 return buf;
1034 }
1035
1036 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1037 const char *device_name, char *data)
1038 {
1039 struct dentry *root;
1040 struct vfsmount *mnt;
1041 char *newargs;
1042
1043 newargs = setup_root_args(data);
1044 if (!newargs)
1045 return ERR_PTR(-ENOMEM);
1046 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1047 newargs);
1048 kfree(newargs);
1049 if (IS_ERR(mnt))
1050 return ERR_CAST(mnt);
1051
1052 root = mount_subtree(mnt, subvol_name);
1053
1054 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1055 struct super_block *s = root->d_sb;
1056 dput(root);
1057 root = ERR_PTR(-EINVAL);
1058 deactivate_locked_super(s);
1059 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
1060 subvol_name);
1061 }
1062
1063 return root;
1064 }
1065
1066 /*
1067 * Find a superblock for the given device / mount point.
1068 *
1069 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1070 * for multiple device setup. Make sure to keep it in sync.
1071 */
1072 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1073 const char *device_name, void *data)
1074 {
1075 struct block_device *bdev = NULL;
1076 struct super_block *s;
1077 struct dentry *root;
1078 struct btrfs_fs_devices *fs_devices = NULL;
1079 struct btrfs_fs_info *fs_info = NULL;
1080 fmode_t mode = FMODE_READ;
1081 char *subvol_name = NULL;
1082 u64 subvol_objectid = 0;
1083 u64 subvol_rootid = 0;
1084 int error = 0;
1085
1086 if (!(flags & MS_RDONLY))
1087 mode |= FMODE_WRITE;
1088
1089 error = btrfs_parse_early_options(data, mode, fs_type,
1090 &subvol_name, &subvol_objectid,
1091 &subvol_rootid, &fs_devices);
1092 if (error) {
1093 kfree(subvol_name);
1094 return ERR_PTR(error);
1095 }
1096
1097 if (subvol_name) {
1098 root = mount_subvol(subvol_name, flags, device_name, data);
1099 kfree(subvol_name);
1100 return root;
1101 }
1102
1103 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1104 if (error)
1105 return ERR_PTR(error);
1106
1107 /*
1108 * Setup a dummy root and fs_info for test/set super. This is because
1109 * we don't actually fill this stuff out until open_ctree, but we need
1110 * it for searching for existing supers, so this lets us do that and
1111 * then open_ctree will properly initialize everything later.
1112 */
1113 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1114 if (!fs_info)
1115 return ERR_PTR(-ENOMEM);
1116
1117 fs_info->fs_devices = fs_devices;
1118
1119 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1120 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1121 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1122 error = -ENOMEM;
1123 goto error_fs_info;
1124 }
1125
1126 error = btrfs_open_devices(fs_devices, mode, fs_type);
1127 if (error)
1128 goto error_fs_info;
1129
1130 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1131 error = -EACCES;
1132 goto error_close_devices;
1133 }
1134
1135 bdev = fs_devices->latest_bdev;
1136 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1137 fs_info);
1138 if (IS_ERR(s)) {
1139 error = PTR_ERR(s);
1140 goto error_close_devices;
1141 }
1142
1143 if (s->s_root) {
1144 btrfs_close_devices(fs_devices);
1145 free_fs_info(fs_info);
1146 if ((flags ^ s->s_flags) & MS_RDONLY)
1147 error = -EBUSY;
1148 } else {
1149 char b[BDEVNAME_SIZE];
1150
1151 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1152 btrfs_sb(s)->bdev_holder = fs_type;
1153 error = btrfs_fill_super(s, fs_devices, data,
1154 flags & MS_SILENT ? 1 : 0);
1155 }
1156
1157 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1158 if (IS_ERR(root))
1159 deactivate_locked_super(s);
1160
1161 return root;
1162
1163 error_close_devices:
1164 btrfs_close_devices(fs_devices);
1165 error_fs_info:
1166 free_fs_info(fs_info);
1167 return ERR_PTR(error);
1168 }
1169
1170 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1171 {
1172 spin_lock_irq(&workers->lock);
1173 workers->max_workers = new_limit;
1174 spin_unlock_irq(&workers->lock);
1175 }
1176
1177 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1178 int new_pool_size, int old_pool_size)
1179 {
1180 if (new_pool_size == old_pool_size)
1181 return;
1182
1183 fs_info->thread_pool_size = new_pool_size;
1184
1185 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1186 old_pool_size, new_pool_size);
1187
1188 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1189 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1190 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1191 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1192 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1193 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1194 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1195 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1196 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1197 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1198 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1199 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1200 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1201 btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1202 new_pool_size);
1203 }
1204
1205 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info,
1206 unsigned long old_opts, int flags)
1207 {
1208 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1209
1210 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1211 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1212 (flags & MS_RDONLY))) {
1213 /* wait for any defraggers to finish */
1214 wait_event(fs_info->transaction_wait,
1215 (atomic_read(&fs_info->defrag_running) == 0));
1216 if (flags & MS_RDONLY)
1217 sync_filesystem(fs_info->sb);
1218 }
1219 }
1220
1221 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1222 unsigned long old_opts)
1223 {
1224 /*
1225 * We need cleanup all defragable inodes if the autodefragment is
1226 * close or the fs is R/O.
1227 */
1228 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1229 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1230 (fs_info->sb->s_flags & MS_RDONLY))) {
1231 btrfs_cleanup_defrag_inodes(fs_info);
1232 }
1233
1234 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1235 }
1236
1237 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1238 {
1239 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1240 struct btrfs_root *root = fs_info->tree_root;
1241 unsigned old_flags = sb->s_flags;
1242 unsigned long old_opts = fs_info->mount_opt;
1243 unsigned long old_compress_type = fs_info->compress_type;
1244 u64 old_max_inline = fs_info->max_inline;
1245 u64 old_alloc_start = fs_info->alloc_start;
1246 int old_thread_pool_size = fs_info->thread_pool_size;
1247 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1248 int ret;
1249
1250 btrfs_remount_prepare(fs_info, old_opts, *flags);
1251
1252 ret = btrfs_parse_options(root, data);
1253 if (ret) {
1254 ret = -EINVAL;
1255 goto restore;
1256 }
1257
1258 btrfs_resize_thread_pool(fs_info,
1259 fs_info->thread_pool_size, old_thread_pool_size);
1260
1261 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1262 goto out;
1263
1264 if (*flags & MS_RDONLY) {
1265 /*
1266 * this also happens on 'umount -rf' or on shutdown, when
1267 * the filesystem is busy.
1268 */
1269 sb->s_flags |= MS_RDONLY;
1270
1271 btrfs_dev_replace_suspend_for_unmount(fs_info);
1272 btrfs_scrub_cancel(fs_info);
1273
1274 ret = btrfs_commit_super(root);
1275 if (ret)
1276 goto restore;
1277 } else {
1278 if (fs_info->fs_devices->rw_devices == 0) {
1279 ret = -EACCES;
1280 goto restore;
1281 }
1282
1283 if (fs_info->fs_devices->missing_devices >
1284 fs_info->num_tolerated_disk_barrier_failures &&
1285 !(*flags & MS_RDONLY)) {
1286 printk(KERN_WARNING
1287 "Btrfs: too many missing devices, writeable remount is not allowed\n");
1288 ret = -EACCES;
1289 goto restore;
1290 }
1291
1292 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1293 ret = -EINVAL;
1294 goto restore;
1295 }
1296
1297 ret = btrfs_cleanup_fs_roots(fs_info);
1298 if (ret)
1299 goto restore;
1300
1301 /* recover relocation */
1302 ret = btrfs_recover_relocation(root);
1303 if (ret)
1304 goto restore;
1305
1306 ret = btrfs_resume_balance_async(fs_info);
1307 if (ret)
1308 goto restore;
1309
1310 ret = btrfs_resume_dev_replace_async(fs_info);
1311 if (ret) {
1312 pr_warn("btrfs: failed to resume dev_replace\n");
1313 goto restore;
1314 }
1315 sb->s_flags &= ~MS_RDONLY;
1316 }
1317 out:
1318 btrfs_remount_cleanup(fs_info, old_opts);
1319 return 0;
1320
1321 restore:
1322 /* We've hit an error - don't reset MS_RDONLY */
1323 if (sb->s_flags & MS_RDONLY)
1324 old_flags |= MS_RDONLY;
1325 sb->s_flags = old_flags;
1326 fs_info->mount_opt = old_opts;
1327 fs_info->compress_type = old_compress_type;
1328 fs_info->max_inline = old_max_inline;
1329 mutex_lock(&fs_info->chunk_mutex);
1330 fs_info->alloc_start = old_alloc_start;
1331 mutex_unlock(&fs_info->chunk_mutex);
1332 btrfs_resize_thread_pool(fs_info,
1333 old_thread_pool_size, fs_info->thread_pool_size);
1334 fs_info->metadata_ratio = old_metadata_ratio;
1335 btrfs_remount_cleanup(fs_info, old_opts);
1336 return ret;
1337 }
1338
1339 /* Used to sort the devices by max_avail(descending sort) */
1340 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1341 const void *dev_info2)
1342 {
1343 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1344 ((struct btrfs_device_info *)dev_info2)->max_avail)
1345 return -1;
1346 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1347 ((struct btrfs_device_info *)dev_info2)->max_avail)
1348 return 1;
1349 else
1350 return 0;
1351 }
1352
1353 /*
1354 * sort the devices by max_avail, in which max free extent size of each device
1355 * is stored.(Descending Sort)
1356 */
1357 static inline void btrfs_descending_sort_devices(
1358 struct btrfs_device_info *devices,
1359 size_t nr_devices)
1360 {
1361 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1362 btrfs_cmp_device_free_bytes, NULL);
1363 }
1364
1365 /*
1366 * The helper to calc the free space on the devices that can be used to store
1367 * file data.
1368 */
1369 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1370 {
1371 struct btrfs_fs_info *fs_info = root->fs_info;
1372 struct btrfs_device_info *devices_info;
1373 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1374 struct btrfs_device *device;
1375 u64 skip_space;
1376 u64 type;
1377 u64 avail_space;
1378 u64 used_space;
1379 u64 min_stripe_size;
1380 int min_stripes = 1, num_stripes = 1;
1381 int i = 0, nr_devices;
1382 int ret;
1383
1384 nr_devices = fs_info->fs_devices->open_devices;
1385 BUG_ON(!nr_devices);
1386
1387 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1388 GFP_NOFS);
1389 if (!devices_info)
1390 return -ENOMEM;
1391
1392 /* calc min stripe number for data space alloction */
1393 type = btrfs_get_alloc_profile(root, 1);
1394 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1395 min_stripes = 2;
1396 num_stripes = nr_devices;
1397 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1398 min_stripes = 2;
1399 num_stripes = 2;
1400 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1401 min_stripes = 4;
1402 num_stripes = 4;
1403 }
1404
1405 if (type & BTRFS_BLOCK_GROUP_DUP)
1406 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1407 else
1408 min_stripe_size = BTRFS_STRIPE_LEN;
1409
1410 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1411 if (!device->in_fs_metadata || !device->bdev ||
1412 device->is_tgtdev_for_dev_replace)
1413 continue;
1414
1415 avail_space = device->total_bytes - device->bytes_used;
1416
1417 /* align with stripe_len */
1418 do_div(avail_space, BTRFS_STRIPE_LEN);
1419 avail_space *= BTRFS_STRIPE_LEN;
1420
1421 /*
1422 * In order to avoid overwritting the superblock on the drive,
1423 * btrfs starts at an offset of at least 1MB when doing chunk
1424 * allocation.
1425 */
1426 skip_space = 1024 * 1024;
1427
1428 /* user can set the offset in fs_info->alloc_start. */
1429 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1430 device->total_bytes)
1431 skip_space = max(fs_info->alloc_start, skip_space);
1432
1433 /*
1434 * btrfs can not use the free space in [0, skip_space - 1],
1435 * we must subtract it from the total. In order to implement
1436 * it, we account the used space in this range first.
1437 */
1438 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1439 &used_space);
1440 if (ret) {
1441 kfree(devices_info);
1442 return ret;
1443 }
1444
1445 /* calc the free space in [0, skip_space - 1] */
1446 skip_space -= used_space;
1447
1448 /*
1449 * we can use the free space in [0, skip_space - 1], subtract
1450 * it from the total.
1451 */
1452 if (avail_space && avail_space >= skip_space)
1453 avail_space -= skip_space;
1454 else
1455 avail_space = 0;
1456
1457 if (avail_space < min_stripe_size)
1458 continue;
1459
1460 devices_info[i].dev = device;
1461 devices_info[i].max_avail = avail_space;
1462
1463 i++;
1464 }
1465
1466 nr_devices = i;
1467
1468 btrfs_descending_sort_devices(devices_info, nr_devices);
1469
1470 i = nr_devices - 1;
1471 avail_space = 0;
1472 while (nr_devices >= min_stripes) {
1473 if (num_stripes > nr_devices)
1474 num_stripes = nr_devices;
1475
1476 if (devices_info[i].max_avail >= min_stripe_size) {
1477 int j;
1478 u64 alloc_size;
1479
1480 avail_space += devices_info[i].max_avail * num_stripes;
1481 alloc_size = devices_info[i].max_avail;
1482 for (j = i + 1 - num_stripes; j <= i; j++)
1483 devices_info[j].max_avail -= alloc_size;
1484 }
1485 i--;
1486 nr_devices--;
1487 }
1488
1489 kfree(devices_info);
1490 *free_bytes = avail_space;
1491 return 0;
1492 }
1493
1494 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1495 {
1496 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1497 struct btrfs_super_block *disk_super = fs_info->super_copy;
1498 struct list_head *head = &fs_info->space_info;
1499 struct btrfs_space_info *found;
1500 u64 total_used = 0;
1501 u64 total_free_data = 0;
1502 int bits = dentry->d_sb->s_blocksize_bits;
1503 __be32 *fsid = (__be32 *)fs_info->fsid;
1504 int ret;
1505
1506 /* holding chunk_muext to avoid allocating new chunks */
1507 mutex_lock(&fs_info->chunk_mutex);
1508 rcu_read_lock();
1509 list_for_each_entry_rcu(found, head, list) {
1510 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1511 total_free_data += found->disk_total - found->disk_used;
1512 total_free_data -=
1513 btrfs_account_ro_block_groups_free_space(found);
1514 }
1515
1516 total_used += found->disk_used;
1517 }
1518 rcu_read_unlock();
1519
1520 buf->f_namelen = BTRFS_NAME_LEN;
1521 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1522 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1523 buf->f_bsize = dentry->d_sb->s_blocksize;
1524 buf->f_type = BTRFS_SUPER_MAGIC;
1525 buf->f_bavail = total_free_data;
1526 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1527 if (ret) {
1528 mutex_unlock(&fs_info->chunk_mutex);
1529 return ret;
1530 }
1531 buf->f_bavail += total_free_data;
1532 buf->f_bavail = buf->f_bavail >> bits;
1533 mutex_unlock(&fs_info->chunk_mutex);
1534
1535 /* We treat it as constant endianness (it doesn't matter _which_)
1536 because we want the fsid to come out the same whether mounted
1537 on a big-endian or little-endian host */
1538 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1539 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1540 /* Mask in the root object ID too, to disambiguate subvols */
1541 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1542 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1543
1544 return 0;
1545 }
1546
1547 static void btrfs_kill_super(struct super_block *sb)
1548 {
1549 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1550 kill_anon_super(sb);
1551 free_fs_info(fs_info);
1552 }
1553
1554 static struct file_system_type btrfs_fs_type = {
1555 .owner = THIS_MODULE,
1556 .name = "btrfs",
1557 .mount = btrfs_mount,
1558 .kill_sb = btrfs_kill_super,
1559 .fs_flags = FS_REQUIRES_DEV,
1560 };
1561 MODULE_ALIAS_FS("btrfs");
1562
1563 /*
1564 * used by btrfsctl to scan devices when no FS is mounted
1565 */
1566 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1567 unsigned long arg)
1568 {
1569 struct btrfs_ioctl_vol_args *vol;
1570 struct btrfs_fs_devices *fs_devices;
1571 int ret = -ENOTTY;
1572
1573 if (!capable(CAP_SYS_ADMIN))
1574 return -EPERM;
1575
1576 vol = memdup_user((void __user *)arg, sizeof(*vol));
1577 if (IS_ERR(vol))
1578 return PTR_ERR(vol);
1579
1580 switch (cmd) {
1581 case BTRFS_IOC_SCAN_DEV:
1582 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1583 &btrfs_fs_type, &fs_devices);
1584 break;
1585 case BTRFS_IOC_DEVICES_READY:
1586 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1587 &btrfs_fs_type, &fs_devices);
1588 if (ret)
1589 break;
1590 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1591 break;
1592 }
1593
1594 kfree(vol);
1595 return ret;
1596 }
1597
1598 static int btrfs_freeze(struct super_block *sb)
1599 {
1600 struct btrfs_trans_handle *trans;
1601 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1602
1603 trans = btrfs_attach_transaction_barrier(root);
1604 if (IS_ERR(trans)) {
1605 /* no transaction, don't bother */
1606 if (PTR_ERR(trans) == -ENOENT)
1607 return 0;
1608 return PTR_ERR(trans);
1609 }
1610 return btrfs_commit_transaction(trans, root);
1611 }
1612
1613 static int btrfs_unfreeze(struct super_block *sb)
1614 {
1615 return 0;
1616 }
1617
1618 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1619 {
1620 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1621 struct btrfs_fs_devices *cur_devices;
1622 struct btrfs_device *dev, *first_dev = NULL;
1623 struct list_head *head;
1624 struct rcu_string *name;
1625
1626 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1627 cur_devices = fs_info->fs_devices;
1628 while (cur_devices) {
1629 head = &cur_devices->devices;
1630 list_for_each_entry(dev, head, dev_list) {
1631 if (dev->missing)
1632 continue;
1633 if (!first_dev || dev->devid < first_dev->devid)
1634 first_dev = dev;
1635 }
1636 cur_devices = cur_devices->seed;
1637 }
1638
1639 if (first_dev) {
1640 rcu_read_lock();
1641 name = rcu_dereference(first_dev->name);
1642 seq_escape(m, name->str, " \t\n\\");
1643 rcu_read_unlock();
1644 } else {
1645 WARN_ON(1);
1646 }
1647 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1648 return 0;
1649 }
1650
1651 static const struct super_operations btrfs_super_ops = {
1652 .drop_inode = btrfs_drop_inode,
1653 .evict_inode = btrfs_evict_inode,
1654 .put_super = btrfs_put_super,
1655 .sync_fs = btrfs_sync_fs,
1656 .show_options = btrfs_show_options,
1657 .show_devname = btrfs_show_devname,
1658 .write_inode = btrfs_write_inode,
1659 .alloc_inode = btrfs_alloc_inode,
1660 .destroy_inode = btrfs_destroy_inode,
1661 .statfs = btrfs_statfs,
1662 .remount_fs = btrfs_remount,
1663 .freeze_fs = btrfs_freeze,
1664 .unfreeze_fs = btrfs_unfreeze,
1665 };
1666
1667 static const struct file_operations btrfs_ctl_fops = {
1668 .unlocked_ioctl = btrfs_control_ioctl,
1669 .compat_ioctl = btrfs_control_ioctl,
1670 .owner = THIS_MODULE,
1671 .llseek = noop_llseek,
1672 };
1673
1674 static struct miscdevice btrfs_misc = {
1675 .minor = BTRFS_MINOR,
1676 .name = "btrfs-control",
1677 .fops = &btrfs_ctl_fops
1678 };
1679
1680 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1681 MODULE_ALIAS("devname:btrfs-control");
1682
1683 static int btrfs_interface_init(void)
1684 {
1685 return misc_register(&btrfs_misc);
1686 }
1687
1688 static void btrfs_interface_exit(void)
1689 {
1690 if (misc_deregister(&btrfs_misc) < 0)
1691 printk(KERN_INFO "btrfs: misc_deregister failed for control device\n");
1692 }
1693
1694 static int __init init_btrfs_fs(void)
1695 {
1696 int err;
1697
1698 err = btrfs_init_sysfs();
1699 if (err)
1700 return err;
1701
1702 btrfs_init_compress();
1703
1704 err = btrfs_init_cachep();
1705 if (err)
1706 goto free_compress;
1707
1708 err = extent_io_init();
1709 if (err)
1710 goto free_cachep;
1711
1712 err = extent_map_init();
1713 if (err)
1714 goto free_extent_io;
1715
1716 err = ordered_data_init();
1717 if (err)
1718 goto free_extent_map;
1719
1720 err = btrfs_delayed_inode_init();
1721 if (err)
1722 goto free_ordered_data;
1723
1724 err = btrfs_auto_defrag_init();
1725 if (err)
1726 goto free_delayed_inode;
1727
1728 err = btrfs_delayed_ref_init();
1729 if (err)
1730 goto free_auto_defrag;
1731
1732 err = btrfs_interface_init();
1733 if (err)
1734 goto free_delayed_ref;
1735
1736 err = register_filesystem(&btrfs_fs_type);
1737 if (err)
1738 goto unregister_ioctl;
1739
1740 btrfs_init_lockdep();
1741
1742 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1743 return 0;
1744
1745 unregister_ioctl:
1746 btrfs_interface_exit();
1747 free_delayed_ref:
1748 btrfs_delayed_ref_exit();
1749 free_auto_defrag:
1750 btrfs_auto_defrag_exit();
1751 free_delayed_inode:
1752 btrfs_delayed_inode_exit();
1753 free_ordered_data:
1754 ordered_data_exit();
1755 free_extent_map:
1756 extent_map_exit();
1757 free_extent_io:
1758 extent_io_exit();
1759 free_cachep:
1760 btrfs_destroy_cachep();
1761 free_compress:
1762 btrfs_exit_compress();
1763 btrfs_exit_sysfs();
1764 return err;
1765 }
1766
1767 static void __exit exit_btrfs_fs(void)
1768 {
1769 btrfs_destroy_cachep();
1770 btrfs_delayed_ref_exit();
1771 btrfs_auto_defrag_exit();
1772 btrfs_delayed_inode_exit();
1773 ordered_data_exit();
1774 extent_map_exit();
1775 extent_io_exit();
1776 btrfs_interface_exit();
1777 unregister_filesystem(&btrfs_fs_type);
1778 btrfs_exit_sysfs();
1779 btrfs_cleanup_fs_uuids();
1780 btrfs_exit_compress();
1781 }
1782
1783 module_init(init_btrfs_fs)
1784 module_exit(exit_btrfs_fs)
1785
1786 MODULE_LICENSE("GPL");
CJK support for tty framebuffer vt