diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/nilfs2/super.c | 1366 |
1 files changed, 1366 insertions, 0 deletions
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c new file mode 100644 index 000000000000..10e82c00aedc --- /dev/null +++ b/fs/nilfs2/super.c | |||
@@ -0,0 +1,1366 @@ | |||
1 | /* | ||
2 | * super.c - NILFS module and super block management. | ||
3 | * | ||
4 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License as published by | ||
8 | * the Free Software Foundation; either version 2 of the License, or | ||
9 | * (at your option) any later version. | ||
10 | * | ||
11 | * This program is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU General Public License | ||
17 | * along with this program; if not, write to the Free Software | ||
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | ||
19 | * | ||
20 | * Written by Ryusuke Konishi <ryusuke@osrg.net> | ||
21 | */ | ||
22 | /* | ||
23 | * linux/fs/ext2/super.c | ||
24 | * | ||
25 | * Copyright (C) 1992, 1993, 1994, 1995 | ||
26 | * Remy Card (card@masi.ibp.fr) | ||
27 | * Laboratoire MASI - Institut Blaise Pascal | ||
28 | * Universite Pierre et Marie Curie (Paris VI) | ||
29 | * | ||
30 | * from | ||
31 | * | ||
32 | * linux/fs/minix/inode.c | ||
33 | * | ||
34 | * Copyright (C) 1991, 1992 Linus Torvalds | ||
35 | * | ||
36 | * Big-endian to little-endian byte-swapping/bitmaps by | ||
37 | * David S. Miller (davem@caip.rutgers.edu), 1995 | ||
38 | */ | ||
39 | |||
40 | #include <linux/module.h> | ||
41 | #include <linux/string.h> | ||
42 | #include <linux/slab.h> | ||
43 | #include <linux/init.h> | ||
44 | #include <linux/blkdev.h> | ||
45 | #include <linux/parser.h> | ||
46 | #include <linux/random.h> | ||
47 | #include <linux/crc32.h> | ||
48 | #include <linux/smp_lock.h> | ||
49 | #include <linux/vfs.h> | ||
50 | #include <linux/writeback.h> | ||
51 | #include <linux/kobject.h> | ||
52 | #include <linux/exportfs.h> | ||
53 | #include "nilfs.h" | ||
54 | #include "mdt.h" | ||
55 | #include "alloc.h" | ||
56 | #include "page.h" | ||
57 | #include "cpfile.h" | ||
58 | #include "ifile.h" | ||
59 | #include "dat.h" | ||
60 | #include "segment.h" | ||
61 | #include "segbuf.h" | ||
62 | |||
63 | MODULE_AUTHOR("NTT Corp."); | ||
64 | MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem " | ||
65 | "(NILFS)"); | ||
66 | MODULE_VERSION(NILFS_VERSION); | ||
67 | MODULE_LICENSE("GPL"); | ||
68 | |||
69 | static int nilfs_remount(struct super_block *sb, int *flags, char *data); | ||
70 | static int test_exclusive_mount(struct file_system_type *fs_type, | ||
71 | struct block_device *bdev, int flags); | ||
72 | |||
73 | /** | ||
74 | * nilfs_error() - report failure condition on a filesystem | ||
75 | * | ||
76 | * nilfs_error() sets an ERROR_FS flag on the superblock as well as | ||
77 | * reporting an error message. It should be called when NILFS detects | ||
78 | * incoherences or defects of meta data on disk. As for sustainable | ||
79 | * errors such as a single-shot I/O error, nilfs_warning() or the printk() | ||
80 | * function should be used instead. | ||
81 | * | ||
82 | * The segment constructor must not call this function because it can | ||
83 | * kill itself. | ||
84 | */ | ||
85 | void nilfs_error(struct super_block *sb, const char *function, | ||
86 | const char *fmt, ...) | ||
87 | { | ||
88 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | ||
89 | va_list args; | ||
90 | |||
91 | va_start(args, fmt); | ||
92 | printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function); | ||
93 | vprintk(fmt, args); | ||
94 | printk("\n"); | ||
95 | va_end(args); | ||
96 | |||
97 | if (!(sb->s_flags & MS_RDONLY)) { | ||
98 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
99 | |||
100 | if (!nilfs_test_opt(sbi, ERRORS_CONT)) | ||
101 | nilfs_detach_segment_constructor(sbi); | ||
102 | |||
103 | down_write(&nilfs->ns_sem); | ||
104 | if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) { | ||
105 | nilfs->ns_mount_state |= NILFS_ERROR_FS; | ||
106 | nilfs->ns_sbp->s_state |= cpu_to_le16(NILFS_ERROR_FS); | ||
107 | nilfs_commit_super(sbi); | ||
108 | } | ||
109 | up_write(&nilfs->ns_sem); | ||
110 | |||
111 | if (nilfs_test_opt(sbi, ERRORS_RO)) { | ||
112 | printk(KERN_CRIT "Remounting filesystem read-only\n"); | ||
113 | sb->s_flags |= MS_RDONLY; | ||
114 | } | ||
115 | } | ||
116 | |||
117 | if (nilfs_test_opt(sbi, ERRORS_PANIC)) | ||
118 | panic("NILFS (device %s): panic forced after error\n", | ||
119 | sb->s_id); | ||
120 | } | ||
121 | |||
122 | void nilfs_warning(struct super_block *sb, const char *function, | ||
123 | const char *fmt, ...) | ||
124 | { | ||
125 | va_list args; | ||
126 | |||
127 | va_start(args, fmt); | ||
128 | printk(KERN_WARNING "NILFS warning (device %s): %s: ", | ||
129 | sb->s_id, function); | ||
130 | vprintk(fmt, args); | ||
131 | printk("\n"); | ||
132 | va_end(args); | ||
133 | } | ||
134 | |||
135 | static struct kmem_cache *nilfs_inode_cachep; | ||
136 | |||
137 | struct inode *nilfs_alloc_inode(struct super_block *sb) | ||
138 | { | ||
139 | struct nilfs_inode_info *ii; | ||
140 | |||
141 | ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS); | ||
142 | if (!ii) | ||
143 | return NULL; | ||
144 | ii->i_bh = NULL; | ||
145 | ii->i_state = 0; | ||
146 | ii->vfs_inode.i_version = 1; | ||
147 | nilfs_btnode_cache_init(&ii->i_btnode_cache); | ||
148 | return &ii->vfs_inode; | ||
149 | } | ||
150 | |||
151 | void nilfs_destroy_inode(struct inode *inode) | ||
152 | { | ||
153 | kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); | ||
154 | } | ||
155 | |||
156 | static void init_once(void *obj) | ||
157 | { | ||
158 | struct nilfs_inode_info *ii = obj; | ||
159 | |||
160 | INIT_LIST_HEAD(&ii->i_dirty); | ||
161 | #ifdef CONFIG_NILFS_XATTR | ||
162 | init_rwsem(&ii->xattr_sem); | ||
163 | #endif | ||
164 | nilfs_btnode_cache_init_once(&ii->i_btnode_cache); | ||
165 | ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union; | ||
166 | inode_init_once(&ii->vfs_inode); | ||
167 | } | ||
168 | |||
169 | static int nilfs_init_inode_cache(void) | ||
170 | { | ||
171 | nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", | ||
172 | sizeof(struct nilfs_inode_info), | ||
173 | 0, SLAB_RECLAIM_ACCOUNT, | ||
174 | init_once); | ||
175 | |||
176 | return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0; | ||
177 | } | ||
178 | |||
179 | static inline void nilfs_destroy_inode_cache(void) | ||
180 | { | ||
181 | kmem_cache_destroy(nilfs_inode_cachep); | ||
182 | } | ||
183 | |||
184 | static void nilfs_clear_inode(struct inode *inode) | ||
185 | { | ||
186 | struct nilfs_inode_info *ii = NILFS_I(inode); | ||
187 | struct nilfs_transaction_info ti; | ||
188 | struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb); | ||
189 | |||
190 | #ifdef CONFIG_NILFS_POSIX_ACL | ||
191 | if (ii->i_acl && ii->i_acl != NILFS_ACL_NOT_CACHED) { | ||
192 | posix_acl_release(ii->i_acl); | ||
193 | ii->i_acl = NILFS_ACL_NOT_CACHED; | ||
194 | } | ||
195 | if (ii->i_default_acl && ii->i_default_acl != NILFS_ACL_NOT_CACHED) { | ||
196 | posix_acl_release(ii->i_default_acl); | ||
197 | ii->i_default_acl = NILFS_ACL_NOT_CACHED; | ||
198 | } | ||
199 | #endif | ||
200 | /* | ||
201 | * Free resources allocated in nilfs_read_inode(), here. | ||
202 | */ | ||
203 | nilfs_transaction_begin(inode->i_sb, &ti, 0); | ||
204 | |||
205 | spin_lock(&sbi->s_inode_lock); | ||
206 | if (!list_empty(&ii->i_dirty)) | ||
207 | list_del_init(&ii->i_dirty); | ||
208 | brelse(ii->i_bh); | ||
209 | ii->i_bh = NULL; | ||
210 | spin_unlock(&sbi->s_inode_lock); | ||
211 | |||
212 | if (test_bit(NILFS_I_BMAP, &ii->i_state)) | ||
213 | nilfs_bmap_clear(ii->i_bmap); | ||
214 | |||
215 | nilfs_btnode_cache_clear(&ii->i_btnode_cache); | ||
216 | |||
217 | nilfs_transaction_end(inode->i_sb, 0); | ||
218 | } | ||
219 | |||
220 | /** | ||
221 | * nilfs_update_last_segment - change pointer to the latest segment | ||
222 | * @sbi: nilfs_sb_info | ||
223 | * @update_cno: flag whether to update checkpoint number. | ||
224 | * | ||
225 | * nilfs_update_last_segment() changes information in the super block | ||
226 | * after a partial segment is written out successfully. The super | ||
227 | * block is marked dirty. It will be written out at the next VFS sync | ||
228 | * operations such as sync_supers() and generic_shutdown_super(). | ||
229 | */ | ||
230 | void nilfs_update_last_segment(struct nilfs_sb_info *sbi, int update_cno) | ||
231 | { | ||
232 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
233 | struct nilfs_super_block *sbp = nilfs->ns_sbp; | ||
234 | |||
235 | /* nilfs->sem must be locked by the caller. */ | ||
236 | spin_lock(&nilfs->ns_last_segment_lock); | ||
237 | if (update_cno) | ||
238 | nilfs->ns_last_cno = nilfs->ns_cno++; | ||
239 | sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq); | ||
240 | sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg); | ||
241 | sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno); | ||
242 | spin_unlock(&nilfs->ns_last_segment_lock); | ||
243 | |||
244 | sbi->s_super->s_dirt = 1; /* must be set if delaying the call of | ||
245 | nilfs_commit_super() */ | ||
246 | } | ||
247 | |||
248 | static int nilfs_sync_super(struct nilfs_sb_info *sbi) | ||
249 | { | ||
250 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
251 | int err; | ||
252 | int barrier_done = 0; | ||
253 | |||
254 | if (nilfs_test_opt(sbi, BARRIER)) { | ||
255 | set_buffer_ordered(nilfs->ns_sbh); | ||
256 | barrier_done = 1; | ||
257 | } | ||
258 | retry: | ||
259 | set_buffer_dirty(nilfs->ns_sbh); | ||
260 | err = sync_dirty_buffer(nilfs->ns_sbh); | ||
261 | if (err == -EOPNOTSUPP && barrier_done) { | ||
262 | nilfs_warning(sbi->s_super, __func__, | ||
263 | "barrier-based sync failed. " | ||
264 | "disabling barriers\n"); | ||
265 | nilfs_clear_opt(sbi, BARRIER); | ||
266 | barrier_done = 0; | ||
267 | clear_buffer_ordered(nilfs->ns_sbh); | ||
268 | goto retry; | ||
269 | } | ||
270 | if (unlikely(err)) | ||
271 | printk(KERN_ERR | ||
272 | "NILFS: unable to write superblock (err=%d)\n", err); | ||
273 | else { | ||
274 | nilfs_dispose_used_segments(nilfs); | ||
275 | clear_nilfs_discontinued(nilfs); | ||
276 | } | ||
277 | |||
278 | return err; | ||
279 | } | ||
280 | |||
281 | int nilfs_commit_super(struct nilfs_sb_info *sbi) | ||
282 | { | ||
283 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
284 | struct nilfs_super_block *sbp = nilfs->ns_sbp; | ||
285 | sector_t nfreeblocks; | ||
286 | int err; | ||
287 | |||
288 | /* nilfs->sem must be locked by the caller. */ | ||
289 | err = nilfs_count_free_blocks(nilfs, &nfreeblocks); | ||
290 | if (unlikely(err)) { | ||
291 | printk(KERN_ERR "NILFS: failed to count free blocks\n"); | ||
292 | return err; | ||
293 | } | ||
294 | sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks); | ||
295 | sbp->s_wtime = cpu_to_le64(get_seconds()); | ||
296 | sbp->s_sum = 0; | ||
297 | sbp->s_sum = crc32_le(nilfs->ns_crc_seed, (unsigned char *)sbp, | ||
298 | le16_to_cpu(sbp->s_bytes)); | ||
299 | |||
300 | sbi->s_super->s_dirt = 0; | ||
301 | return nilfs_sync_super(sbi); | ||
302 | } | ||
303 | |||
304 | static void nilfs_put_super(struct super_block *sb) | ||
305 | { | ||
306 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | ||
307 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
308 | |||
309 | nilfs_detach_segment_constructor(sbi); | ||
310 | |||
311 | if (!(sb->s_flags & MS_RDONLY)) { | ||
312 | down_write(&nilfs->ns_sem); | ||
313 | nilfs->ns_sbp->s_state = cpu_to_le16(nilfs->ns_mount_state); | ||
314 | nilfs_commit_super(sbi); | ||
315 | up_write(&nilfs->ns_sem); | ||
316 | } | ||
317 | |||
318 | nilfs_detach_checkpoint(sbi); | ||
319 | put_nilfs(sbi->s_nilfs); | ||
320 | sbi->s_super = NULL; | ||
321 | sb->s_fs_info = NULL; | ||
322 | kfree(sbi); | ||
323 | } | ||
324 | |||
325 | /** | ||
326 | * nilfs_write_super - write super block(s) of NILFS | ||
327 | * @sb: super_block | ||
328 | * | ||
329 | * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and | ||
330 | * clears s_dirt. This function is called in the section protected by | ||
331 | * lock_super(). | ||
332 | * | ||
333 | * The s_dirt flag is managed by each filesystem and we protect it by ns_sem | ||
334 | * of the struct the_nilfs. Lock order must be as follows: | ||
335 | * | ||
336 | * 1. lock_super() | ||
337 | * 2. down_write(&nilfs->ns_sem) | ||
338 | * | ||
339 | * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer | ||
340 | * of the super block (nilfs->ns_sbp). | ||
341 | * | ||
342 | * In most cases, VFS functions call lock_super() before calling these | ||
343 | * methods. So we must be careful not to bring on deadlocks when using | ||
344 | * lock_super(); see generic_shutdown_super(), write_super(), and so on. | ||
345 | * | ||
346 | * Note that order of lock_kernel() and lock_super() depends on contexts | ||
347 | * of VFS. We should also note that lock_kernel() can be used in its | ||
348 | * protective section and only the outermost one has an effect. | ||
349 | */ | ||
350 | static void nilfs_write_super(struct super_block *sb) | ||
351 | { | ||
352 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | ||
353 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
354 | |||
355 | down_write(&nilfs->ns_sem); | ||
356 | if (!(sb->s_flags & MS_RDONLY)) | ||
357 | nilfs_commit_super(sbi); | ||
358 | sb->s_dirt = 0; | ||
359 | up_write(&nilfs->ns_sem); | ||
360 | } | ||
361 | |||
362 | static int nilfs_sync_fs(struct super_block *sb, int wait) | ||
363 | { | ||
364 | int err = 0; | ||
365 | |||
366 | /* This function is called when super block should be written back */ | ||
367 | if (wait) | ||
368 | err = nilfs_construct_segment(sb); | ||
369 | return err; | ||
370 | } | ||
371 | |||
372 | int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) | ||
373 | { | ||
374 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
375 | struct nilfs_checkpoint *raw_cp; | ||
376 | struct buffer_head *bh_cp; | ||
377 | int err; | ||
378 | |||
379 | down_write(&nilfs->ns_sem); | ||
380 | list_add(&sbi->s_list, &nilfs->ns_supers); | ||
381 | up_write(&nilfs->ns_sem); | ||
382 | |||
383 | sbi->s_ifile = nilfs_mdt_new( | ||
384 | nilfs, sbi->s_super, NILFS_IFILE_INO, NILFS_IFILE_GFP); | ||
385 | if (!sbi->s_ifile) | ||
386 | return -ENOMEM; | ||
387 | |||
388 | err = nilfs_palloc_init_blockgroup(sbi->s_ifile, nilfs->ns_inode_size); | ||
389 | if (unlikely(err)) | ||
390 | goto failed; | ||
391 | |||
392 | err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, | ||
393 | &bh_cp); | ||
394 | if (unlikely(err)) { | ||
395 | if (err == -ENOENT || err == -EINVAL) { | ||
396 | printk(KERN_ERR | ||
397 | "NILFS: Invalid checkpoint " | ||
398 | "(checkpoint number=%llu)\n", | ||
399 | (unsigned long long)cno); | ||
400 | err = -EINVAL; | ||
401 | } | ||
402 | goto failed; | ||
403 | } | ||
404 | err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode); | ||
405 | if (unlikely(err)) | ||
406 | goto failed_bh; | ||
407 | atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count)); | ||
408 | atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count)); | ||
409 | |||
410 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); | ||
411 | return 0; | ||
412 | |||
413 | failed_bh: | ||
414 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); | ||
415 | failed: | ||
416 | nilfs_mdt_destroy(sbi->s_ifile); | ||
417 | sbi->s_ifile = NULL; | ||
418 | |||
419 | down_write(&nilfs->ns_sem); | ||
420 | list_del_init(&sbi->s_list); | ||
421 | up_write(&nilfs->ns_sem); | ||
422 | |||
423 | return err; | ||
424 | } | ||
425 | |||
426 | void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi) | ||
427 | { | ||
428 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
429 | |||
430 | nilfs_mdt_clear(sbi->s_ifile); | ||
431 | nilfs_mdt_destroy(sbi->s_ifile); | ||
432 | sbi->s_ifile = NULL; | ||
433 | down_write(&nilfs->ns_sem); | ||
434 | list_del_init(&sbi->s_list); | ||
435 | up_write(&nilfs->ns_sem); | ||
436 | } | ||
437 | |||
438 | static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi) | ||
439 | { | ||
440 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
441 | int err = 0; | ||
442 | |||
443 | down_write(&nilfs->ns_sem); | ||
444 | if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) { | ||
445 | nilfs->ns_mount_state |= NILFS_VALID_FS; | ||
446 | err = nilfs_commit_super(sbi); | ||
447 | if (likely(!err)) | ||
448 | printk(KERN_INFO "NILFS: recovery complete.\n"); | ||
449 | } | ||
450 | up_write(&nilfs->ns_sem); | ||
451 | return err; | ||
452 | } | ||
453 | |||
454 | static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) | ||
455 | { | ||
456 | struct super_block *sb = dentry->d_sb; | ||
457 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | ||
458 | unsigned long long blocks; | ||
459 | unsigned long overhead; | ||
460 | unsigned long nrsvblocks; | ||
461 | sector_t nfreeblocks; | ||
462 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
463 | int err; | ||
464 | |||
465 | /* | ||
466 | * Compute all of the segment blocks | ||
467 | * | ||
468 | * The blocks before first segment and after last segment | ||
469 | * are excluded. | ||
470 | */ | ||
471 | blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments | ||
472 | - nilfs->ns_first_data_block; | ||
473 | nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment; | ||
474 | |||
475 | /* | ||
476 | * Compute the overhead | ||
477 | * | ||
478 | * When distributing meta data blocks outside semgent structure, | ||
479 | * We must count them as the overhead. | ||
480 | */ | ||
481 | overhead = 0; | ||
482 | |||
483 | err = nilfs_count_free_blocks(nilfs, &nfreeblocks); | ||
484 | if (unlikely(err)) | ||
485 | return err; | ||
486 | |||
487 | buf->f_type = NILFS_SUPER_MAGIC; | ||
488 | buf->f_bsize = sb->s_blocksize; | ||
489 | buf->f_blocks = blocks - overhead; | ||
490 | buf->f_bfree = nfreeblocks; | ||
491 | buf->f_bavail = (buf->f_bfree >= nrsvblocks) ? | ||
492 | (buf->f_bfree - nrsvblocks) : 0; | ||
493 | buf->f_files = atomic_read(&sbi->s_inodes_count); | ||
494 | buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */ | ||
495 | buf->f_namelen = NILFS_NAME_LEN; | ||
496 | return 0; | ||
497 | } | ||
498 | |||
499 | static struct super_operations nilfs_sops = { | ||
500 | .alloc_inode = nilfs_alloc_inode, | ||
501 | .destroy_inode = nilfs_destroy_inode, | ||
502 | .dirty_inode = nilfs_dirty_inode, | ||
503 | /* .write_inode = nilfs_write_inode, */ | ||
504 | /* .put_inode = nilfs_put_inode, */ | ||
505 | /* .drop_inode = nilfs_drop_inode, */ | ||
506 | .delete_inode = nilfs_delete_inode, | ||
507 | .put_super = nilfs_put_super, | ||
508 | .write_super = nilfs_write_super, | ||
509 | .sync_fs = nilfs_sync_fs, | ||
510 | /* .write_super_lockfs */ | ||
511 | /* .unlockfs */ | ||
512 | .statfs = nilfs_statfs, | ||
513 | .remount_fs = nilfs_remount, | ||
514 | .clear_inode = nilfs_clear_inode, | ||
515 | /* .umount_begin */ | ||
516 | /* .show_options */ | ||
517 | }; | ||
518 | |||
519 | static struct inode * | ||
520 | nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation) | ||
521 | { | ||
522 | struct inode *inode; | ||
523 | |||
524 | if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO && | ||
525 | ino != NILFS_SKETCH_INO) | ||
526 | return ERR_PTR(-ESTALE); | ||
527 | |||
528 | inode = nilfs_iget(sb, ino); | ||
529 | if (IS_ERR(inode)) | ||
530 | return ERR_CAST(inode); | ||
531 | if (generation && inode->i_generation != generation) { | ||
532 | iput(inode); | ||
533 | return ERR_PTR(-ESTALE); | ||
534 | } | ||
535 | |||
536 | return inode; | ||
537 | } | ||
538 | |||
539 | static struct dentry * | ||
540 | nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, | ||
541 | int fh_type) | ||
542 | { | ||
543 | return generic_fh_to_dentry(sb, fid, fh_len, fh_type, | ||
544 | nilfs_nfs_get_inode); | ||
545 | } | ||
546 | |||
547 | static struct dentry * | ||
548 | nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, | ||
549 | int fh_type) | ||
550 | { | ||
551 | return generic_fh_to_parent(sb, fid, fh_len, fh_type, | ||
552 | nilfs_nfs_get_inode); | ||
553 | } | ||
554 | |||
555 | static struct export_operations nilfs_export_ops = { | ||
556 | .fh_to_dentry = nilfs_fh_to_dentry, | ||
557 | .fh_to_parent = nilfs_fh_to_parent, | ||
558 | .get_parent = nilfs_get_parent, | ||
559 | }; | ||
560 | |||
561 | enum { | ||
562 | Opt_err_cont, Opt_err_panic, Opt_err_ro, | ||
563 | Opt_barrier, Opt_snapshot, Opt_order, | ||
564 | Opt_err, | ||
565 | }; | ||
566 | |||
567 | static match_table_t tokens = { | ||
568 | {Opt_err_cont, "errors=continue"}, | ||
569 | {Opt_err_panic, "errors=panic"}, | ||
570 | {Opt_err_ro, "errors=remount-ro"}, | ||
571 | {Opt_barrier, "barrier=%s"}, | ||
572 | {Opt_snapshot, "cp=%u"}, | ||
573 | {Opt_order, "order=%s"}, | ||
574 | {Opt_err, NULL} | ||
575 | }; | ||
576 | |||
577 | static int match_bool(substring_t *s, int *result) | ||
578 | { | ||
579 | int len = s->to - s->from; | ||
580 | |||
581 | if (strncmp(s->from, "on", len) == 0) | ||
582 | *result = 1; | ||
583 | else if (strncmp(s->from, "off", len) == 0) | ||
584 | *result = 0; | ||
585 | else | ||
586 | return 1; | ||
587 | return 0; | ||
588 | } | ||
589 | |||
590 | static int parse_options(char *options, struct super_block *sb) | ||
591 | { | ||
592 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | ||
593 | char *p; | ||
594 | substring_t args[MAX_OPT_ARGS]; | ||
595 | int option; | ||
596 | |||
597 | if (!options) | ||
598 | return 1; | ||
599 | |||
600 | while ((p = strsep(&options, ",")) != NULL) { | ||
601 | int token; | ||
602 | if (!*p) | ||
603 | continue; | ||
604 | |||
605 | token = match_token(p, tokens, args); | ||
606 | switch (token) { | ||
607 | case Opt_barrier: | ||
608 | if (match_bool(&args[0], &option)) | ||
609 | return 0; | ||
610 | if (option) | ||
611 | nilfs_set_opt(sbi, BARRIER); | ||
612 | else | ||
613 | nilfs_clear_opt(sbi, BARRIER); | ||
614 | break; | ||
615 | case Opt_order: | ||
616 | if (strcmp(args[0].from, "relaxed") == 0) | ||
617 | /* Ordered data semantics */ | ||
618 | nilfs_clear_opt(sbi, STRICT_ORDER); | ||
619 | else if (strcmp(args[0].from, "strict") == 0) | ||
620 | /* Strict in-order semantics */ | ||
621 | nilfs_set_opt(sbi, STRICT_ORDER); | ||
622 | else | ||
623 | return 0; | ||
624 | break; | ||
625 | case Opt_err_panic: | ||
626 | nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC); | ||
627 | break; | ||
628 | case Opt_err_ro: | ||
629 | nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO); | ||
630 | break; | ||
631 | case Opt_err_cont: | ||
632 | nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT); | ||
633 | break; | ||
634 | case Opt_snapshot: | ||
635 | if (match_int(&args[0], &option) || option <= 0) | ||
636 | return 0; | ||
637 | if (!(sb->s_flags & MS_RDONLY)) | ||
638 | return 0; | ||
639 | sbi->s_snapshot_cno = option; | ||
640 | nilfs_set_opt(sbi, SNAPSHOT); | ||
641 | break; | ||
642 | default: | ||
643 | printk(KERN_ERR | ||
644 | "NILFS: Unrecognized mount option \"%s\"\n", p); | ||
645 | return 0; | ||
646 | } | ||
647 | } | ||
648 | return 1; | ||
649 | } | ||
650 | |||
651 | static inline void | ||
652 | nilfs_set_default_options(struct nilfs_sb_info *sbi, | ||
653 | struct nilfs_super_block *sbp) | ||
654 | { | ||
655 | sbi->s_mount_opt = | ||
656 | NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER; | ||
657 | } | ||
658 | |||
659 | static int nilfs_setup_super(struct nilfs_sb_info *sbi) | ||
660 | { | ||
661 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
662 | struct nilfs_super_block *sbp = nilfs->ns_sbp; | ||
663 | int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count); | ||
664 | int mnt_count = le16_to_cpu(sbp->s_mnt_count); | ||
665 | |||
666 | /* nilfs->sem must be locked by the caller. */ | ||
667 | if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) { | ||
668 | printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); | ||
669 | } else if (nilfs->ns_mount_state & NILFS_ERROR_FS) { | ||
670 | printk(KERN_WARNING | ||
671 | "NILFS warning: mounting fs with errors\n"); | ||
672 | #if 0 | ||
673 | } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { | ||
674 | printk(KERN_WARNING | ||
675 | "NILFS warning: maximal mount count reached\n"); | ||
676 | #endif | ||
677 | } | ||
678 | if (!max_mnt_count) | ||
679 | sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); | ||
680 | |||
681 | sbp->s_mnt_count = cpu_to_le16(mnt_count + 1); | ||
682 | sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS); | ||
683 | sbp->s_mtime = cpu_to_le64(get_seconds()); | ||
684 | return nilfs_commit_super(sbi); | ||
685 | } | ||
686 | |||
687 | struct nilfs_super_block * | ||
688 | nilfs_load_super_block(struct super_block *sb, struct buffer_head **pbh) | ||
689 | { | ||
690 | int blocksize; | ||
691 | unsigned long offset, sb_index; | ||
692 | |||
693 | /* | ||
694 | * Adjusting block size | ||
695 | * Blocksize will be enlarged when it is smaller than hardware | ||
696 | * sector size. | ||
697 | * Disk format of superblock does not change. | ||
698 | */ | ||
699 | blocksize = sb_min_blocksize(sb, BLOCK_SIZE); | ||
700 | if (!blocksize) { | ||
701 | printk(KERN_ERR | ||
702 | "NILFS: unable to set blocksize of superblock\n"); | ||
703 | return NULL; | ||
704 | } | ||
705 | sb_index = NILFS_SB_OFFSET_BYTES / blocksize; | ||
706 | offset = NILFS_SB_OFFSET_BYTES % blocksize; | ||
707 | |||
708 | *pbh = sb_bread(sb, sb_index); | ||
709 | if (!*pbh) { | ||
710 | printk(KERN_ERR "NILFS: unable to read superblock\n"); | ||
711 | return NULL; | ||
712 | } | ||
713 | return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); | ||
714 | } | ||
715 | |||
716 | struct nilfs_super_block * | ||
717 | nilfs_reload_super_block(struct super_block *sb, struct buffer_head **pbh, | ||
718 | int blocksize) | ||
719 | { | ||
720 | struct nilfs_super_block *sbp; | ||
721 | unsigned long offset, sb_index; | ||
722 | int hw_blocksize = bdev_hardsect_size(sb->s_bdev); | ||
723 | |||
724 | if (blocksize < hw_blocksize) { | ||
725 | printk(KERN_ERR | ||
726 | "NILFS: blocksize %d too small for device " | ||
727 | "(sector-size = %d).\n", | ||
728 | blocksize, hw_blocksize); | ||
729 | goto failed_sbh; | ||
730 | } | ||
731 | brelse(*pbh); | ||
732 | sb_set_blocksize(sb, blocksize); | ||
733 | |||
734 | sb_index = NILFS_SB_OFFSET_BYTES / blocksize; | ||
735 | offset = NILFS_SB_OFFSET_BYTES % blocksize; | ||
736 | |||
737 | *pbh = sb_bread(sb, sb_index); | ||
738 | if (!*pbh) { | ||
739 | printk(KERN_ERR | ||
740 | "NILFS: cannot read superblock on 2nd try.\n"); | ||
741 | goto failed; | ||
742 | } | ||
743 | |||
744 | sbp = (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); | ||
745 | if (sbp->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { | ||
746 | printk(KERN_ERR | ||
747 | "NILFS: !? Magic mismatch on 2nd try.\n"); | ||
748 | goto failed_sbh; | ||
749 | } | ||
750 | return sbp; | ||
751 | |||
752 | failed_sbh: | ||
753 | brelse(*pbh); | ||
754 | |||
755 | failed: | ||
756 | return NULL; | ||
757 | } | ||
758 | |||
759 | int nilfs_store_magic_and_option(struct super_block *sb, | ||
760 | struct nilfs_super_block *sbp, | ||
761 | char *data) | ||
762 | { | ||
763 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | ||
764 | |||
765 | /* trying to fill super (1st stage) */ | ||
766 | sb->s_magic = le16_to_cpu(sbp->s_magic); | ||
767 | |||
768 | /* FS independent flags */ | ||
769 | #ifdef NILFS_ATIME_DISABLE | ||
770 | sb->s_flags |= MS_NOATIME; | ||
771 | #endif | ||
772 | |||
773 | if (sb->s_magic != NILFS_SUPER_MAGIC) { | ||
774 | printk("NILFS: Can't find nilfs on dev %s.\n", sb->s_id); | ||
775 | return -EINVAL; | ||
776 | } | ||
777 | |||
778 | nilfs_set_default_options(sbi, sbp); | ||
779 | |||
780 | sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid); | ||
781 | sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid); | ||
782 | sbi->s_interval = le32_to_cpu(sbp->s_c_interval); | ||
783 | sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max); | ||
784 | |||
785 | if (!parse_options(data, sb)) | ||
786 | return -EINVAL; | ||
787 | |||
788 | return 0; | ||
789 | } | ||
790 | |||
791 | /** | ||
792 | * nilfs_fill_super() - initialize a super block instance | ||
793 | * @sb: super_block | ||
794 | * @data: mount options | ||
795 | * @silent: silent mode flag | ||
796 | * @nilfs: the_nilfs struct | ||
797 | * | ||
798 | * This function is called exclusively by bd_mount_mutex. | ||
799 | * So, the recovery process is protected from other simultaneous mounts. | ||
800 | */ | ||
801 | static int | ||
802 | nilfs_fill_super(struct super_block *sb, void *data, int silent, | ||
803 | struct the_nilfs *nilfs) | ||
804 | { | ||
805 | struct nilfs_sb_info *sbi; | ||
806 | struct inode *root; | ||
807 | __u64 cno; | ||
808 | int err; | ||
809 | |||
810 | sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); | ||
811 | if (!sbi) | ||
812 | return -ENOMEM; | ||
813 | |||
814 | sb->s_fs_info = sbi; | ||
815 | |||
816 | get_nilfs(nilfs); | ||
817 | sbi->s_nilfs = nilfs; | ||
818 | sbi->s_super = sb; | ||
819 | |||
820 | err = init_nilfs(nilfs, sbi, (char *)data); | ||
821 | if (err) | ||
822 | goto failed_sbi; | ||
823 | |||
824 | spin_lock_init(&sbi->s_inode_lock); | ||
825 | INIT_LIST_HEAD(&sbi->s_dirty_files); | ||
826 | INIT_LIST_HEAD(&sbi->s_list); | ||
827 | |||
828 | /* | ||
829 | * Following initialization is overlapped because | ||
830 | * nilfs_sb_info structure has been cleared at the beginning. | ||
831 | * But we reserve them to keep our interest and make ready | ||
832 | * for the future change. | ||
833 | */ | ||
834 | get_random_bytes(&sbi->s_next_generation, | ||
835 | sizeof(sbi->s_next_generation)); | ||
836 | spin_lock_init(&sbi->s_next_gen_lock); | ||
837 | |||
838 | sb->s_op = &nilfs_sops; | ||
839 | sb->s_export_op = &nilfs_export_ops; | ||
840 | sb->s_root = NULL; | ||
841 | |||
842 | if (!nilfs_loaded(nilfs)) { | ||
843 | err = load_nilfs(nilfs, sbi); | ||
844 | if (err) | ||
845 | goto failed_sbi; | ||
846 | } | ||
847 | cno = nilfs_last_cno(nilfs); | ||
848 | |||
849 | if (sb->s_flags & MS_RDONLY) { | ||
850 | if (nilfs_test_opt(sbi, SNAPSHOT)) { | ||
851 | if (!nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, | ||
852 | sbi->s_snapshot_cno)) { | ||
853 | printk(KERN_ERR | ||
854 | "NILFS: The specified checkpoint is " | ||
855 | "not a snapshot " | ||
856 | "(checkpoint number=%llu).\n", | ||
857 | (unsigned long long)sbi->s_snapshot_cno); | ||
858 | err = -EINVAL; | ||
859 | goto failed_sbi; | ||
860 | } | ||
861 | cno = sbi->s_snapshot_cno; | ||
862 | } else | ||
863 | /* Read-only mount */ | ||
864 | sbi->s_snapshot_cno = cno; | ||
865 | } | ||
866 | |||
867 | err = nilfs_attach_checkpoint(sbi, cno); | ||
868 | if (err) { | ||
869 | printk(KERN_ERR "NILFS: error loading a checkpoint" | ||
870 | " (checkpoint number=%llu).\n", (unsigned long long)cno); | ||
871 | goto failed_sbi; | ||
872 | } | ||
873 | |||
874 | if (!(sb->s_flags & MS_RDONLY)) { | ||
875 | err = nilfs_attach_segment_constructor(sbi, NULL); | ||
876 | if (err) | ||
877 | goto failed_checkpoint; | ||
878 | } | ||
879 | |||
880 | root = nilfs_iget(sb, NILFS_ROOT_INO); | ||
881 | if (IS_ERR(root)) { | ||
882 | printk(KERN_ERR "NILFS: get root inode failed\n"); | ||
883 | err = PTR_ERR(root); | ||
884 | goto failed_segctor; | ||
885 | } | ||
886 | if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { | ||
887 | iput(root); | ||
888 | printk(KERN_ERR "NILFS: corrupt root inode.\n"); | ||
889 | err = -EINVAL; | ||
890 | goto failed_segctor; | ||
891 | } | ||
892 | sb->s_root = d_alloc_root(root); | ||
893 | if (!sb->s_root) { | ||
894 | iput(root); | ||
895 | printk(KERN_ERR "NILFS: get root dentry failed\n"); | ||
896 | err = -ENOMEM; | ||
897 | goto failed_segctor; | ||
898 | } | ||
899 | |||
900 | if (!(sb->s_flags & MS_RDONLY)) { | ||
901 | down_write(&nilfs->ns_sem); | ||
902 | nilfs_setup_super(sbi); | ||
903 | up_write(&nilfs->ns_sem); | ||
904 | } | ||
905 | |||
906 | err = nilfs_mark_recovery_complete(sbi); | ||
907 | if (unlikely(err)) { | ||
908 | printk(KERN_ERR "NILFS: recovery failed.\n"); | ||
909 | goto failed_root; | ||
910 | } | ||
911 | |||
912 | return 0; | ||
913 | |||
914 | failed_root: | ||
915 | dput(sb->s_root); | ||
916 | sb->s_root = NULL; | ||
917 | |||
918 | failed_segctor: | ||
919 | nilfs_detach_segment_constructor(sbi); | ||
920 | |||
921 | failed_checkpoint: | ||
922 | nilfs_detach_checkpoint(sbi); | ||
923 | |||
924 | failed_sbi: | ||
925 | put_nilfs(nilfs); | ||
926 | sb->s_fs_info = NULL; | ||
927 | kfree(sbi); | ||
928 | return err; | ||
929 | } | ||
930 | |||
931 | static int nilfs_remount(struct super_block *sb, int *flags, char *data) | ||
932 | { | ||
933 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | ||
934 | struct nilfs_super_block *sbp; | ||
935 | struct the_nilfs *nilfs = sbi->s_nilfs; | ||
936 | unsigned long old_sb_flags; | ||
937 | struct nilfs_mount_options old_opts; | ||
938 | int err; | ||
939 | |||
940 | old_sb_flags = sb->s_flags; | ||
941 | old_opts.mount_opt = sbi->s_mount_opt; | ||
942 | old_opts.snapshot_cno = sbi->s_snapshot_cno; | ||
943 | |||
944 | if (!parse_options(data, sb)) { | ||
945 | err = -EINVAL; | ||
946 | goto restore_opts; | ||
947 | } | ||
948 | sb->s_flags = (sb->s_flags & ~MS_POSIXACL); | ||
949 | |||
950 | if ((*flags & MS_RDONLY) && | ||
951 | sbi->s_snapshot_cno != old_opts.snapshot_cno) { | ||
952 | printk(KERN_WARNING "NILFS (device %s): couldn't " | ||
953 | "remount to a different snapshot. \n", | ||
954 | sb->s_id); | ||
955 | err = -EINVAL; | ||
956 | goto restore_opts; | ||
957 | } | ||
958 | |||
959 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) | ||
960 | goto out; | ||
961 | if (*flags & MS_RDONLY) { | ||
962 | /* Shutting down the segment constructor */ | ||
963 | nilfs_detach_segment_constructor(sbi); | ||
964 | sb->s_flags |= MS_RDONLY; | ||
965 | |||
966 | sbi->s_snapshot_cno = nilfs_last_cno(nilfs); | ||
967 | /* nilfs_set_opt(sbi, SNAPSHOT); */ | ||
968 | |||
969 | /* | ||
970 | * Remounting a valid RW partition RDONLY, so set | ||
971 | * the RDONLY flag and then mark the partition as valid again. | ||
972 | */ | ||
973 | down_write(&nilfs->ns_sem); | ||
974 | sbp = nilfs->ns_sbp; | ||
975 | if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) && | ||
976 | (nilfs->ns_mount_state & NILFS_VALID_FS)) | ||
977 | sbp->s_state = cpu_to_le16(nilfs->ns_mount_state); | ||
978 | sbp->s_mtime = cpu_to_le64(get_seconds()); | ||
979 | nilfs_commit_super(sbi); | ||
980 | up_write(&nilfs->ns_sem); | ||
981 | } else { | ||
982 | /* | ||
983 | * Mounting a RDONLY partition read-write, so reread and | ||
984 | * store the current valid flag. (It may have been changed | ||
985 | * by fsck since we originally mounted the partition.) | ||
986 | */ | ||
987 | down(&sb->s_bdev->bd_mount_sem); | ||
988 | /* Check existing RW-mount */ | ||
989 | if (test_exclusive_mount(sb->s_type, sb->s_bdev, 0)) { | ||
990 | printk(KERN_WARNING "NILFS (device %s): couldn't " | ||
991 | "remount because a RW-mount exists.\n", | ||
992 | sb->s_id); | ||
993 | err = -EBUSY; | ||
994 | goto rw_remount_failed; | ||
995 | } | ||
996 | if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) { | ||
997 | printk(KERN_WARNING "NILFS (device %s): couldn't " | ||
998 | "remount because the current RO-mount is not " | ||
999 | "the latest one.\n", | ||
1000 | sb->s_id); | ||
1001 | err = -EINVAL; | ||
1002 | goto rw_remount_failed; | ||
1003 | } | ||
1004 | sb->s_flags &= ~MS_RDONLY; | ||
1005 | nilfs_clear_opt(sbi, SNAPSHOT); | ||
1006 | sbi->s_snapshot_cno = 0; | ||
1007 | |||
1008 | err = nilfs_attach_segment_constructor(sbi, NULL); | ||
1009 | if (err) | ||
1010 | goto rw_remount_failed; | ||
1011 | |||
1012 | down_write(&nilfs->ns_sem); | ||
1013 | nilfs_setup_super(sbi); | ||
1014 | up_write(&nilfs->ns_sem); | ||
1015 | |||
1016 | up(&sb->s_bdev->bd_mount_sem); | ||
1017 | } | ||
1018 | out: | ||
1019 | return 0; | ||
1020 | |||
1021 | rw_remount_failed: | ||
1022 | up(&sb->s_bdev->bd_mount_sem); | ||
1023 | restore_opts: | ||
1024 | sb->s_flags = old_sb_flags; | ||
1025 | sbi->s_mount_opt = old_opts.mount_opt; | ||
1026 | sbi->s_snapshot_cno = old_opts.snapshot_cno; | ||
1027 | return err; | ||
1028 | } | ||
1029 | |||
1030 | struct nilfs_super_data { | ||
1031 | struct block_device *bdev; | ||
1032 | __u64 cno; | ||
1033 | int flags; | ||
1034 | }; | ||
1035 | |||
1036 | /** | ||
1037 | * nilfs_identify - pre-read mount options needed to identify mount instance | ||
1038 | * @data: mount options | ||
1039 | * @sd: nilfs_super_data | ||
1040 | */ | ||
1041 | static int nilfs_identify(char *data, struct nilfs_super_data *sd) | ||
1042 | { | ||
1043 | char *p, *options = data; | ||
1044 | substring_t args[MAX_OPT_ARGS]; | ||
1045 | int option, token; | ||
1046 | int ret = 0; | ||
1047 | |||
1048 | do { | ||
1049 | p = strsep(&options, ","); | ||
1050 | if (p != NULL && *p) { | ||
1051 | token = match_token(p, tokens, args); | ||
1052 | if (token == Opt_snapshot) { | ||
1053 | if (!(sd->flags & MS_RDONLY)) | ||
1054 | ret++; | ||
1055 | else { | ||
1056 | ret = match_int(&args[0], &option); | ||
1057 | if (!ret) { | ||
1058 | if (option > 0) | ||
1059 | sd->cno = option; | ||
1060 | else | ||
1061 | ret++; | ||
1062 | } | ||
1063 | } | ||
1064 | } | ||
1065 | if (ret) | ||
1066 | printk(KERN_ERR | ||
1067 | "NILFS: invalid mount option: %s\n", p); | ||
1068 | } | ||
1069 | if (!options) | ||
1070 | break; | ||
1071 | BUG_ON(options == data); | ||
1072 | *(options - 1) = ','; | ||
1073 | } while (!ret); | ||
1074 | return ret; | ||
1075 | } | ||
1076 | |||
1077 | static int nilfs_set_bdev_super(struct super_block *s, void *data) | ||
1078 | { | ||
1079 | struct nilfs_super_data *sd = data; | ||
1080 | |||
1081 | s->s_bdev = sd->bdev; | ||
1082 | s->s_dev = s->s_bdev->bd_dev; | ||
1083 | return 0; | ||
1084 | } | ||
1085 | |||
1086 | static int nilfs_test_bdev_super(struct super_block *s, void *data) | ||
1087 | { | ||
1088 | struct nilfs_super_data *sd = data; | ||
1089 | |||
1090 | return s->s_bdev == sd->bdev; | ||
1091 | } | ||
1092 | |||
1093 | static int nilfs_test_bdev_super2(struct super_block *s, void *data) | ||
1094 | { | ||
1095 | struct nilfs_super_data *sd = data; | ||
1096 | int ret; | ||
1097 | |||
1098 | if (s->s_bdev != sd->bdev) | ||
1099 | return 0; | ||
1100 | |||
1101 | if (!((s->s_flags | sd->flags) & MS_RDONLY)) | ||
1102 | return 1; /* Reuse an old R/W-mode super_block */ | ||
1103 | |||
1104 | if (s->s_flags & sd->flags & MS_RDONLY) { | ||
1105 | if (down_read_trylock(&s->s_umount)) { | ||
1106 | ret = s->s_root && | ||
1107 | (sd->cno == NILFS_SB(s)->s_snapshot_cno); | ||
1108 | up_read(&s->s_umount); | ||
1109 | /* | ||
1110 | * This path is locked with sb_lock by sget(). | ||
1111 | * So, drop_super() causes deadlock. | ||
1112 | */ | ||
1113 | return ret; | ||
1114 | } | ||
1115 | } | ||
1116 | return 0; | ||
1117 | } | ||
1118 | |||
1119 | static int | ||
1120 | nilfs_get_sb(struct file_system_type *fs_type, int flags, | ||
1121 | const char *dev_name, void *data, struct vfsmount *mnt) | ||
1122 | { | ||
1123 | struct nilfs_super_data sd; | ||
1124 | struct super_block *s, *s2; | ||
1125 | struct the_nilfs *nilfs = NULL; | ||
1126 | int err, need_to_close = 1; | ||
1127 | |||
1128 | sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type); | ||
1129 | if (IS_ERR(sd.bdev)) | ||
1130 | return PTR_ERR(sd.bdev); | ||
1131 | |||
1132 | /* | ||
1133 | * To get mount instance using sget() vfs-routine, NILFS needs | ||
1134 | * much more information than normal filesystems to identify mount | ||
1135 | * instance. For snapshot mounts, not only a mount type (ro-mount | ||
1136 | * or rw-mount) but also a checkpoint number is required. | ||
1137 | * The results are passed in sget() using nilfs_super_data. | ||
1138 | */ | ||
1139 | sd.cno = 0; | ||
1140 | sd.flags = flags; | ||
1141 | if (nilfs_identify((char *)data, &sd)) { | ||
1142 | err = -EINVAL; | ||
1143 | goto failed; | ||
1144 | } | ||
1145 | |||
1146 | /* | ||
1147 | * once the super is inserted into the list by sget, s_umount | ||
1148 | * will protect the lockfs code from trying to start a snapshot | ||
1149 | * while we are mounting | ||
1150 | */ | ||
1151 | down(&sd.bdev->bd_mount_sem); | ||
1152 | if (!sd.cno && | ||
1153 | (err = test_exclusive_mount(fs_type, sd.bdev, flags ^ MS_RDONLY))) { | ||
1154 | err = (err < 0) ? : -EBUSY; | ||
1155 | goto failed_unlock; | ||
1156 | } | ||
1157 | |||
1158 | /* | ||
1159 | * Phase-1: search any existent instance and get the_nilfs | ||
1160 | */ | ||
1161 | s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd); | ||
1162 | if (IS_ERR(s)) | ||
1163 | goto error_s; | ||
1164 | |||
1165 | if (!s->s_root) { | ||
1166 | err = -ENOMEM; | ||
1167 | nilfs = alloc_nilfs(sd.bdev); | ||
1168 | if (!nilfs) | ||
1169 | goto cancel_new; | ||
1170 | } else { | ||
1171 | struct nilfs_sb_info *sbi = NILFS_SB(s); | ||
1172 | |||
1173 | BUG_ON(!sbi || !sbi->s_nilfs); | ||
1174 | /* | ||
1175 | * s_umount protects super_block from unmount process; | ||
1176 | * It covers pointers of nilfs_sb_info and the_nilfs. | ||
1177 | */ | ||
1178 | nilfs = sbi->s_nilfs; | ||
1179 | get_nilfs(nilfs); | ||
1180 | up_write(&s->s_umount); | ||
1181 | |||
1182 | /* | ||
1183 | * Phase-2: search specified snapshot or R/W mode super_block | ||
1184 | */ | ||
1185 | if (!sd.cno) | ||
1186 | /* trying to get the latest checkpoint. */ | ||
1187 | sd.cno = nilfs_last_cno(nilfs); | ||
1188 | |||
1189 | s2 = sget(fs_type, nilfs_test_bdev_super2, | ||
1190 | nilfs_set_bdev_super, &sd); | ||
1191 | deactivate_super(s); | ||
1192 | /* | ||
1193 | * Although deactivate_super() invokes close_bdev_exclusive() at | ||
1194 | * kill_block_super(). Here, s is an existent mount; we need | ||
1195 | * one more close_bdev_exclusive() call. | ||
1196 | */ | ||
1197 | s = s2; | ||
1198 | if (IS_ERR(s)) | ||
1199 | goto error_s; | ||
1200 | } | ||
1201 | |||
1202 | if (!s->s_root) { | ||
1203 | char b[BDEVNAME_SIZE]; | ||
1204 | |||
1205 | s->s_flags = flags; | ||
1206 | strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id)); | ||
1207 | sb_set_blocksize(s, block_size(sd.bdev)); | ||
1208 | |||
1209 | err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs); | ||
1210 | if (err) | ||
1211 | goto cancel_new; | ||
1212 | |||
1213 | s->s_flags |= MS_ACTIVE; | ||
1214 | need_to_close = 0; | ||
1215 | } else if (!(s->s_flags & MS_RDONLY)) { | ||
1216 | err = -EBUSY; | ||
1217 | } | ||
1218 | |||
1219 | up(&sd.bdev->bd_mount_sem); | ||
1220 | put_nilfs(nilfs); | ||
1221 | if (need_to_close) | ||
1222 | close_bdev_exclusive(sd.bdev, flags); | ||
1223 | simple_set_mnt(mnt, s); | ||
1224 | return 0; | ||
1225 | |||
1226 | error_s: | ||
1227 | up(&sd.bdev->bd_mount_sem); | ||
1228 | if (nilfs) | ||
1229 | put_nilfs(nilfs); | ||
1230 | close_bdev_exclusive(sd.bdev, flags); | ||
1231 | return PTR_ERR(s); | ||
1232 | |||
1233 | failed_unlock: | ||
1234 | up(&sd.bdev->bd_mount_sem); | ||
1235 | failed: | ||
1236 | close_bdev_exclusive(sd.bdev, flags); | ||
1237 | |||
1238 | return err; | ||
1239 | |||
1240 | cancel_new: | ||
1241 | /* Abandoning the newly allocated superblock */ | ||
1242 | up(&sd.bdev->bd_mount_sem); | ||
1243 | if (nilfs) | ||
1244 | put_nilfs(nilfs); | ||
1245 | up_write(&s->s_umount); | ||
1246 | deactivate_super(s); | ||
1247 | /* | ||
1248 | * deactivate_super() invokes close_bdev_exclusive(). | ||
1249 | * We must finish all post-cleaning before this call; | ||
1250 | * put_nilfs() and unlocking bd_mount_sem need the block device. | ||
1251 | */ | ||
1252 | return err; | ||
1253 | } | ||
1254 | |||
1255 | static int nilfs_test_bdev_super3(struct super_block *s, void *data) | ||
1256 | { | ||
1257 | struct nilfs_super_data *sd = data; | ||
1258 | int ret; | ||
1259 | |||
1260 | if (s->s_bdev != sd->bdev) | ||
1261 | return 0; | ||
1262 | if (down_read_trylock(&s->s_umount)) { | ||
1263 | ret = (s->s_flags & MS_RDONLY) && s->s_root && | ||
1264 | nilfs_test_opt(NILFS_SB(s), SNAPSHOT); | ||
1265 | up_read(&s->s_umount); | ||
1266 | if (ret) | ||
1267 | return 0; /* ignore snapshot mounts */ | ||
1268 | } | ||
1269 | return !((sd->flags ^ s->s_flags) & MS_RDONLY); | ||
1270 | } | ||
1271 | |||
1272 | static int __false_bdev_super(struct super_block *s, void *data) | ||
1273 | { | ||
1274 | #if 0 /* XXX: workaround for lock debug. This is not good idea */ | ||
1275 | up_write(&s->s_umount); | ||
1276 | #endif | ||
1277 | return -EFAULT; | ||
1278 | } | ||
1279 | |||
1280 | /** | ||
1281 | * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not. | ||
1282 | * fs_type: filesystem type | ||
1283 | * bdev: block device | ||
1284 | * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount) | ||
1285 | * res: pointer to an integer to store result | ||
1286 | * | ||
1287 | * This function must be called within a section protected by bd_mount_mutex. | ||
1288 | */ | ||
1289 | static int test_exclusive_mount(struct file_system_type *fs_type, | ||
1290 | struct block_device *bdev, int flags) | ||
1291 | { | ||
1292 | struct super_block *s; | ||
1293 | struct nilfs_super_data sd = { .flags = flags, .bdev = bdev }; | ||
1294 | |||
1295 | s = sget(fs_type, nilfs_test_bdev_super3, __false_bdev_super, &sd); | ||
1296 | if (IS_ERR(s)) { | ||
1297 | if (PTR_ERR(s) != -EFAULT) | ||
1298 | return PTR_ERR(s); | ||
1299 | return 0; /* Not found */ | ||
1300 | } | ||
1301 | up_write(&s->s_umount); | ||
1302 | deactivate_super(s); | ||
1303 | return 1; /* Found */ | ||
1304 | } | ||
1305 | |||
1306 | struct file_system_type nilfs_fs_type = { | ||
1307 | .owner = THIS_MODULE, | ||
1308 | .name = "nilfs2", | ||
1309 | .get_sb = nilfs_get_sb, | ||
1310 | .kill_sb = kill_block_super, | ||
1311 | .fs_flags = FS_REQUIRES_DEV, | ||
1312 | }; | ||
1313 | |||
1314 | static int __init init_nilfs_fs(void) | ||
1315 | { | ||
1316 | int err; | ||
1317 | |||
1318 | err = nilfs_init_inode_cache(); | ||
1319 | if (err) | ||
1320 | goto failed; | ||
1321 | |||
1322 | err = nilfs_init_transaction_cache(); | ||
1323 | if (err) | ||
1324 | goto failed_inode_cache; | ||
1325 | |||
1326 | err = nilfs_init_segbuf_cache(); | ||
1327 | if (err) | ||
1328 | goto failed_transaction_cache; | ||
1329 | |||
1330 | err = nilfs_btree_path_cache_init(); | ||
1331 | if (err) | ||
1332 | goto failed_segbuf_cache; | ||
1333 | |||
1334 | err = register_filesystem(&nilfs_fs_type); | ||
1335 | if (err) | ||
1336 | goto failed_btree_path_cache; | ||
1337 | |||
1338 | return 0; | ||
1339 | |||
1340 | failed_btree_path_cache: | ||
1341 | nilfs_btree_path_cache_destroy(); | ||
1342 | |||
1343 | failed_segbuf_cache: | ||
1344 | nilfs_destroy_segbuf_cache(); | ||
1345 | |||
1346 | failed_transaction_cache: | ||
1347 | nilfs_destroy_transaction_cache(); | ||
1348 | |||
1349 | failed_inode_cache: | ||
1350 | nilfs_destroy_inode_cache(); | ||
1351 | |||
1352 | failed: | ||
1353 | return err; | ||
1354 | } | ||
1355 | |||
1356 | static void __exit exit_nilfs_fs(void) | ||
1357 | { | ||
1358 | nilfs_destroy_segbuf_cache(); | ||
1359 | nilfs_destroy_transaction_cache(); | ||
1360 | nilfs_destroy_inode_cache(); | ||
1361 | nilfs_btree_path_cache_destroy(); | ||
1362 | unregister_filesystem(&nilfs_fs_type); | ||
1363 | } | ||
1364 | |||
1365 | module_init(init_nilfs_fs) | ||
1366 | module_exit(exit_nilfs_fs) | ||