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783f6184 RK |
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)"); | |
783f6184 RK |
66 | MODULE_LICENSE("GPL"); |
67 | ||
8c85e125 | 68 | static void nilfs_write_super(struct super_block *sb); |
783f6184 RK |
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; | |
e339ad31 RK |
106 | nilfs->ns_sbp[0]->s_state |= |
107 | cpu_to_le16(NILFS_ERROR_FS); | |
108 | nilfs_commit_super(sbi, 1); | |
783f6184 RK |
109 | } |
110 | up_write(&nilfs->ns_sem); | |
111 | ||
112 | if (nilfs_test_opt(sbi, ERRORS_RO)) { | |
113 | printk(KERN_CRIT "Remounting filesystem read-only\n"); | |
114 | sb->s_flags |= MS_RDONLY; | |
115 | } | |
116 | } | |
117 | ||
118 | if (nilfs_test_opt(sbi, ERRORS_PANIC)) | |
119 | panic("NILFS (device %s): panic forced after error\n", | |
120 | sb->s_id); | |
121 | } | |
122 | ||
123 | void nilfs_warning(struct super_block *sb, const char *function, | |
124 | const char *fmt, ...) | |
125 | { | |
126 | va_list args; | |
127 | ||
128 | va_start(args, fmt); | |
129 | printk(KERN_WARNING "NILFS warning (device %s): %s: ", | |
130 | sb->s_id, function); | |
131 | vprintk(fmt, args); | |
132 | printk("\n"); | |
133 | va_end(args); | |
134 | } | |
135 | ||
136 | static struct kmem_cache *nilfs_inode_cachep; | |
137 | ||
138 | struct inode *nilfs_alloc_inode(struct super_block *sb) | |
139 | { | |
140 | struct nilfs_inode_info *ii; | |
141 | ||
142 | ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS); | |
143 | if (!ii) | |
144 | return NULL; | |
145 | ii->i_bh = NULL; | |
146 | ii->i_state = 0; | |
147 | ii->vfs_inode.i_version = 1; | |
148 | nilfs_btnode_cache_init(&ii->i_btnode_cache); | |
149 | return &ii->vfs_inode; | |
150 | } | |
151 | ||
152 | void nilfs_destroy_inode(struct inode *inode) | |
153 | { | |
154 | kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); | |
155 | } | |
156 | ||
157 | static void init_once(void *obj) | |
158 | { | |
159 | struct nilfs_inode_info *ii = obj; | |
160 | ||
161 | INIT_LIST_HEAD(&ii->i_dirty); | |
162 | #ifdef CONFIG_NILFS_XATTR | |
163 | init_rwsem(&ii->xattr_sem); | |
164 | #endif | |
165 | nilfs_btnode_cache_init_once(&ii->i_btnode_cache); | |
166 | ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union; | |
167 | inode_init_once(&ii->vfs_inode); | |
168 | } | |
169 | ||
170 | static int nilfs_init_inode_cache(void) | |
171 | { | |
172 | nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", | |
173 | sizeof(struct nilfs_inode_info), | |
174 | 0, SLAB_RECLAIM_ACCOUNT, | |
175 | init_once); | |
176 | ||
177 | return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0; | |
178 | } | |
179 | ||
180 | static inline void nilfs_destroy_inode_cache(void) | |
181 | { | |
182 | kmem_cache_destroy(nilfs_inode_cachep); | |
183 | } | |
184 | ||
185 | static void nilfs_clear_inode(struct inode *inode) | |
186 | { | |
187 | struct nilfs_inode_info *ii = NILFS_I(inode); | |
783f6184 RK |
188 | |
189 | #ifdef CONFIG_NILFS_POSIX_ACL | |
190 | if (ii->i_acl && ii->i_acl != NILFS_ACL_NOT_CACHED) { | |
191 | posix_acl_release(ii->i_acl); | |
192 | ii->i_acl = NILFS_ACL_NOT_CACHED; | |
193 | } | |
194 | if (ii->i_default_acl && ii->i_default_acl != NILFS_ACL_NOT_CACHED) { | |
195 | posix_acl_release(ii->i_default_acl); | |
196 | ii->i_default_acl = NILFS_ACL_NOT_CACHED; | |
197 | } | |
198 | #endif | |
199 | /* | |
200 | * Free resources allocated in nilfs_read_inode(), here. | |
201 | */ | |
a2e7d2df | 202 | BUG_ON(!list_empty(&ii->i_dirty)); |
783f6184 RK |
203 | brelse(ii->i_bh); |
204 | ii->i_bh = NULL; | |
783f6184 RK |
205 | |
206 | if (test_bit(NILFS_I_BMAP, &ii->i_state)) | |
207 | nilfs_bmap_clear(ii->i_bmap); | |
208 | ||
209 | nilfs_btnode_cache_clear(&ii->i_btnode_cache); | |
783f6184 RK |
210 | } |
211 | ||
e339ad31 | 212 | static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb) |
783f6184 RK |
213 | { |
214 | struct the_nilfs *nilfs = sbi->s_nilfs; | |
215 | int err; | |
216 | int barrier_done = 0; | |
217 | ||
218 | if (nilfs_test_opt(sbi, BARRIER)) { | |
e339ad31 | 219 | set_buffer_ordered(nilfs->ns_sbh[0]); |
783f6184 RK |
220 | barrier_done = 1; |
221 | } | |
222 | retry: | |
e339ad31 RK |
223 | set_buffer_dirty(nilfs->ns_sbh[0]); |
224 | err = sync_dirty_buffer(nilfs->ns_sbh[0]); | |
783f6184 RK |
225 | if (err == -EOPNOTSUPP && barrier_done) { |
226 | nilfs_warning(sbi->s_super, __func__, | |
227 | "barrier-based sync failed. " | |
228 | "disabling barriers\n"); | |
229 | nilfs_clear_opt(sbi, BARRIER); | |
230 | barrier_done = 0; | |
e339ad31 | 231 | clear_buffer_ordered(nilfs->ns_sbh[0]); |
783f6184 RK |
232 | goto retry; |
233 | } | |
e339ad31 | 234 | if (unlikely(err)) { |
783f6184 RK |
235 | printk(KERN_ERR |
236 | "NILFS: unable to write superblock (err=%d)\n", err); | |
e339ad31 RK |
237 | if (err == -EIO && nilfs->ns_sbh[1]) { |
238 | nilfs_fall_back_super_block(nilfs); | |
239 | goto retry; | |
240 | } | |
241 | } else { | |
242 | struct nilfs_super_block *sbp = nilfs->ns_sbp[0]; | |
243 | ||
244 | /* | |
245 | * The latest segment becomes trailable from the position | |
246 | * written in superblock. | |
247 | */ | |
783f6184 | 248 | clear_nilfs_discontinued(nilfs); |
e339ad31 RK |
249 | |
250 | /* update GC protection for recent segments */ | |
251 | if (nilfs->ns_sbh[1]) { | |
252 | sbp = NULL; | |
253 | if (dupsb) { | |
254 | set_buffer_dirty(nilfs->ns_sbh[1]); | |
255 | if (!sync_dirty_buffer(nilfs->ns_sbh[1])) | |
256 | sbp = nilfs->ns_sbp[1]; | |
257 | } | |
258 | } | |
259 | if (sbp) { | |
260 | spin_lock(&nilfs->ns_last_segment_lock); | |
261 | nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq); | |
262 | spin_unlock(&nilfs->ns_last_segment_lock); | |
263 | } | |
783f6184 RK |
264 | } |
265 | ||
266 | return err; | |
267 | } | |
268 | ||
e339ad31 | 269 | int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb) |
783f6184 RK |
270 | { |
271 | struct the_nilfs *nilfs = sbi->s_nilfs; | |
e339ad31 | 272 | struct nilfs_super_block **sbp = nilfs->ns_sbp; |
783f6184 | 273 | sector_t nfreeblocks; |
e339ad31 | 274 | time_t t; |
783f6184 RK |
275 | int err; |
276 | ||
277 | /* nilfs->sem must be locked by the caller. */ | |
e339ad31 RK |
278 | if (sbp[0]->s_magic != NILFS_SUPER_MAGIC) { |
279 | if (sbp[1] && sbp[1]->s_magic == NILFS_SUPER_MAGIC) | |
280 | nilfs_swap_super_block(nilfs); | |
281 | else { | |
282 | printk(KERN_CRIT "NILFS: superblock broke on dev %s\n", | |
283 | sbi->s_super->s_id); | |
284 | return -EIO; | |
285 | } | |
286 | } | |
783f6184 RK |
287 | err = nilfs_count_free_blocks(nilfs, &nfreeblocks); |
288 | if (unlikely(err)) { | |
289 | printk(KERN_ERR "NILFS: failed to count free blocks\n"); | |
290 | return err; | |
291 | } | |
e339ad31 RK |
292 | spin_lock(&nilfs->ns_last_segment_lock); |
293 | sbp[0]->s_last_seq = cpu_to_le64(nilfs->ns_last_seq); | |
294 | sbp[0]->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg); | |
295 | sbp[0]->s_last_cno = cpu_to_le64(nilfs->ns_last_cno); | |
296 | spin_unlock(&nilfs->ns_last_segment_lock); | |
297 | ||
298 | t = get_seconds(); | |
299 | nilfs->ns_sbwtime[0] = t; | |
300 | sbp[0]->s_free_blocks_count = cpu_to_le64(nfreeblocks); | |
301 | sbp[0]->s_wtime = cpu_to_le64(t); | |
302 | sbp[0]->s_sum = 0; | |
303 | sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, | |
304 | (unsigned char *)sbp[0], | |
305 | nilfs->ns_sbsize)); | |
306 | if (dupsb && sbp[1]) { | |
307 | memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); | |
308 | nilfs->ns_sbwtime[1] = t; | |
309 | } | |
783f6184 | 310 | sbi->s_super->s_dirt = 0; |
e339ad31 | 311 | return nilfs_sync_super(sbi, dupsb); |
783f6184 RK |
312 | } |
313 | ||
314 | static void nilfs_put_super(struct super_block *sb) | |
315 | { | |
316 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | |
317 | struct the_nilfs *nilfs = sbi->s_nilfs; | |
318 | ||
6cfd0148 CH |
319 | lock_kernel(); |
320 | ||
8c85e125 CH |
321 | if (sb->s_dirt) |
322 | nilfs_write_super(sb); | |
323 | ||
783f6184 RK |
324 | nilfs_detach_segment_constructor(sbi); |
325 | ||
326 | if (!(sb->s_flags & MS_RDONLY)) { | |
327 | down_write(&nilfs->ns_sem); | |
e339ad31 RK |
328 | nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state); |
329 | nilfs_commit_super(sbi, 1); | |
783f6184 RK |
330 | up_write(&nilfs->ns_sem); |
331 | } | |
332 | ||
333 | nilfs_detach_checkpoint(sbi); | |
334 | put_nilfs(sbi->s_nilfs); | |
335 | sbi->s_super = NULL; | |
336 | sb->s_fs_info = NULL; | |
337 | kfree(sbi); | |
6cfd0148 CH |
338 | |
339 | unlock_kernel(); | |
783f6184 RK |
340 | } |
341 | ||
342 | /** | |
343 | * nilfs_write_super - write super block(s) of NILFS | |
344 | * @sb: super_block | |
345 | * | |
346 | * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and | |
347 | * clears s_dirt. This function is called in the section protected by | |
348 | * lock_super(). | |
349 | * | |
350 | * The s_dirt flag is managed by each filesystem and we protect it by ns_sem | |
351 | * of the struct the_nilfs. Lock order must be as follows: | |
352 | * | |
353 | * 1. lock_super() | |
354 | * 2. down_write(&nilfs->ns_sem) | |
355 | * | |
356 | * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer | |
e339ad31 | 357 | * of the super block (nilfs->ns_sbp[]). |
783f6184 RK |
358 | * |
359 | * In most cases, VFS functions call lock_super() before calling these | |
360 | * methods. So we must be careful not to bring on deadlocks when using | |
361 | * lock_super(); see generic_shutdown_super(), write_super(), and so on. | |
362 | * | |
363 | * Note that order of lock_kernel() and lock_super() depends on contexts | |
364 | * of VFS. We should also note that lock_kernel() can be used in its | |
365 | * protective section and only the outermost one has an effect. | |
366 | */ | |
367 | static void nilfs_write_super(struct super_block *sb) | |
368 | { | |
369 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | |
370 | struct the_nilfs *nilfs = sbi->s_nilfs; | |
371 | ||
372 | down_write(&nilfs->ns_sem); | |
e339ad31 RK |
373 | if (!(sb->s_flags & MS_RDONLY)) { |
374 | struct nilfs_super_block **sbp = nilfs->ns_sbp; | |
375 | u64 t = get_seconds(); | |
376 | int dupsb; | |
377 | ||
378 | if (!nilfs_discontinued(nilfs) && t >= nilfs->ns_sbwtime[0] && | |
379 | t < nilfs->ns_sbwtime[0] + NILFS_SB_FREQ) { | |
380 | up_write(&nilfs->ns_sem); | |
381 | return; | |
382 | } | |
383 | dupsb = sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ; | |
384 | nilfs_commit_super(sbi, dupsb); | |
385 | } | |
783f6184 RK |
386 | sb->s_dirt = 0; |
387 | up_write(&nilfs->ns_sem); | |
388 | } | |
389 | ||
390 | static int nilfs_sync_fs(struct super_block *sb, int wait) | |
391 | { | |
392 | int err = 0; | |
393 | ||
d731e063 CH |
394 | nilfs_write_super(sb); |
395 | ||
783f6184 RK |
396 | /* This function is called when super block should be written back */ |
397 | if (wait) | |
398 | err = nilfs_construct_segment(sb); | |
399 | return err; | |
400 | } | |
401 | ||
402 | int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) | |
403 | { | |
404 | struct the_nilfs *nilfs = sbi->s_nilfs; | |
405 | struct nilfs_checkpoint *raw_cp; | |
406 | struct buffer_head *bh_cp; | |
407 | int err; | |
408 | ||
409 | down_write(&nilfs->ns_sem); | |
410 | list_add(&sbi->s_list, &nilfs->ns_supers); | |
411 | up_write(&nilfs->ns_sem); | |
412 | ||
413 | sbi->s_ifile = nilfs_mdt_new( | |
414 | nilfs, sbi->s_super, NILFS_IFILE_INO, NILFS_IFILE_GFP); | |
415 | if (!sbi->s_ifile) | |
416 | return -ENOMEM; | |
417 | ||
418 | err = nilfs_palloc_init_blockgroup(sbi->s_ifile, nilfs->ns_inode_size); | |
419 | if (unlikely(err)) | |
420 | goto failed; | |
421 | ||
422 | err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, | |
423 | &bh_cp); | |
424 | if (unlikely(err)) { | |
425 | if (err == -ENOENT || err == -EINVAL) { | |
426 | printk(KERN_ERR | |
427 | "NILFS: Invalid checkpoint " | |
428 | "(checkpoint number=%llu)\n", | |
429 | (unsigned long long)cno); | |
430 | err = -EINVAL; | |
431 | } | |
432 | goto failed; | |
433 | } | |
434 | err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode); | |
435 | if (unlikely(err)) | |
436 | goto failed_bh; | |
437 | atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count)); | |
438 | atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count)); | |
439 | ||
440 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); | |
441 | return 0; | |
442 | ||
443 | failed_bh: | |
444 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); | |
445 | failed: | |
446 | nilfs_mdt_destroy(sbi->s_ifile); | |
447 | sbi->s_ifile = NULL; | |
448 | ||
449 | down_write(&nilfs->ns_sem); | |
450 | list_del_init(&sbi->s_list); | |
451 | up_write(&nilfs->ns_sem); | |
452 | ||
453 | return err; | |
454 | } | |
455 | ||
456 | void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi) | |
457 | { | |
458 | struct the_nilfs *nilfs = sbi->s_nilfs; | |
459 | ||
460 | nilfs_mdt_clear(sbi->s_ifile); | |
461 | nilfs_mdt_destroy(sbi->s_ifile); | |
462 | sbi->s_ifile = NULL; | |
463 | down_write(&nilfs->ns_sem); | |
464 | list_del_init(&sbi->s_list); | |
465 | up_write(&nilfs->ns_sem); | |
466 | } | |
467 | ||
468 | static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi) | |
469 | { | |
470 | struct the_nilfs *nilfs = sbi->s_nilfs; | |
471 | int err = 0; | |
472 | ||
473 | down_write(&nilfs->ns_sem); | |
474 | if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) { | |
475 | nilfs->ns_mount_state |= NILFS_VALID_FS; | |
e339ad31 | 476 | err = nilfs_commit_super(sbi, 1); |
783f6184 RK |
477 | if (likely(!err)) |
478 | printk(KERN_INFO "NILFS: recovery complete.\n"); | |
479 | } | |
480 | up_write(&nilfs->ns_sem); | |
481 | return err; | |
482 | } | |
483 | ||
484 | static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) | |
485 | { | |
486 | struct super_block *sb = dentry->d_sb; | |
487 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | |
c306af23 RK |
488 | struct the_nilfs *nilfs = sbi->s_nilfs; |
489 | u64 id = huge_encode_dev(sb->s_bdev->bd_dev); | |
783f6184 RK |
490 | unsigned long long blocks; |
491 | unsigned long overhead; | |
492 | unsigned long nrsvblocks; | |
493 | sector_t nfreeblocks; | |
783f6184 RK |
494 | int err; |
495 | ||
496 | /* | |
497 | * Compute all of the segment blocks | |
498 | * | |
499 | * The blocks before first segment and after last segment | |
500 | * are excluded. | |
501 | */ | |
502 | blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments | |
503 | - nilfs->ns_first_data_block; | |
504 | nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment; | |
505 | ||
506 | /* | |
507 | * Compute the overhead | |
508 | * | |
509 | * When distributing meta data blocks outside semgent structure, | |
510 | * We must count them as the overhead. | |
511 | */ | |
512 | overhead = 0; | |
513 | ||
514 | err = nilfs_count_free_blocks(nilfs, &nfreeblocks); | |
515 | if (unlikely(err)) | |
516 | return err; | |
517 | ||
518 | buf->f_type = NILFS_SUPER_MAGIC; | |
519 | buf->f_bsize = sb->s_blocksize; | |
520 | buf->f_blocks = blocks - overhead; | |
521 | buf->f_bfree = nfreeblocks; | |
522 | buf->f_bavail = (buf->f_bfree >= nrsvblocks) ? | |
523 | (buf->f_bfree - nrsvblocks) : 0; | |
524 | buf->f_files = atomic_read(&sbi->s_inodes_count); | |
525 | buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */ | |
526 | buf->f_namelen = NILFS_NAME_LEN; | |
c306af23 RK |
527 | buf->f_fsid.val[0] = (u32)id; |
528 | buf->f_fsid.val[1] = (u32)(id >> 32); | |
529 | ||
783f6184 RK |
530 | return 0; |
531 | } | |
532 | ||
533 | static struct super_operations nilfs_sops = { | |
534 | .alloc_inode = nilfs_alloc_inode, | |
535 | .destroy_inode = nilfs_destroy_inode, | |
536 | .dirty_inode = nilfs_dirty_inode, | |
537 | /* .write_inode = nilfs_write_inode, */ | |
538 | /* .put_inode = nilfs_put_inode, */ | |
539 | /* .drop_inode = nilfs_drop_inode, */ | |
540 | .delete_inode = nilfs_delete_inode, | |
541 | .put_super = nilfs_put_super, | |
542 | .write_super = nilfs_write_super, | |
543 | .sync_fs = nilfs_sync_fs, | |
544 | /* .write_super_lockfs */ | |
545 | /* .unlockfs */ | |
546 | .statfs = nilfs_statfs, | |
547 | .remount_fs = nilfs_remount, | |
548 | .clear_inode = nilfs_clear_inode, | |
549 | /* .umount_begin */ | |
550 | /* .show_options */ | |
551 | }; | |
552 | ||
553 | static struct inode * | |
554 | nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation) | |
555 | { | |
556 | struct inode *inode; | |
557 | ||
558 | if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO && | |
559 | ino != NILFS_SKETCH_INO) | |
560 | return ERR_PTR(-ESTALE); | |
561 | ||
562 | inode = nilfs_iget(sb, ino); | |
563 | if (IS_ERR(inode)) | |
564 | return ERR_CAST(inode); | |
565 | if (generation && inode->i_generation != generation) { | |
566 | iput(inode); | |
567 | return ERR_PTR(-ESTALE); | |
568 | } | |
569 | ||
570 | return inode; | |
571 | } | |
572 | ||
573 | static struct dentry * | |
574 | nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, | |
575 | int fh_type) | |
576 | { | |
577 | return generic_fh_to_dentry(sb, fid, fh_len, fh_type, | |
578 | nilfs_nfs_get_inode); | |
579 | } | |
580 | ||
581 | static struct dentry * | |
582 | nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, | |
583 | int fh_type) | |
584 | { | |
585 | return generic_fh_to_parent(sb, fid, fh_len, fh_type, | |
586 | nilfs_nfs_get_inode); | |
587 | } | |
588 | ||
589 | static struct export_operations nilfs_export_ops = { | |
590 | .fh_to_dentry = nilfs_fh_to_dentry, | |
591 | .fh_to_parent = nilfs_fh_to_parent, | |
592 | .get_parent = nilfs_get_parent, | |
593 | }; | |
594 | ||
595 | enum { | |
596 | Opt_err_cont, Opt_err_panic, Opt_err_ro, | |
597 | Opt_barrier, Opt_snapshot, Opt_order, | |
598 | Opt_err, | |
599 | }; | |
600 | ||
601 | static match_table_t tokens = { | |
602 | {Opt_err_cont, "errors=continue"}, | |
603 | {Opt_err_panic, "errors=panic"}, | |
604 | {Opt_err_ro, "errors=remount-ro"}, | |
605 | {Opt_barrier, "barrier=%s"}, | |
606 | {Opt_snapshot, "cp=%u"}, | |
607 | {Opt_order, "order=%s"}, | |
608 | {Opt_err, NULL} | |
609 | }; | |
610 | ||
611 | static int match_bool(substring_t *s, int *result) | |
612 | { | |
613 | int len = s->to - s->from; | |
614 | ||
615 | if (strncmp(s->from, "on", len) == 0) | |
616 | *result = 1; | |
617 | else if (strncmp(s->from, "off", len) == 0) | |
618 | *result = 0; | |
619 | else | |
620 | return 1; | |
621 | return 0; | |
622 | } | |
623 | ||
624 | static int parse_options(char *options, struct super_block *sb) | |
625 | { | |
626 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | |
627 | char *p; | |
628 | substring_t args[MAX_OPT_ARGS]; | |
629 | int option; | |
630 | ||
631 | if (!options) | |
632 | return 1; | |
633 | ||
634 | while ((p = strsep(&options, ",")) != NULL) { | |
635 | int token; | |
636 | if (!*p) | |
637 | continue; | |
638 | ||
639 | token = match_token(p, tokens, args); | |
640 | switch (token) { | |
641 | case Opt_barrier: | |
642 | if (match_bool(&args[0], &option)) | |
643 | return 0; | |
644 | if (option) | |
645 | nilfs_set_opt(sbi, BARRIER); | |
646 | else | |
647 | nilfs_clear_opt(sbi, BARRIER); | |
648 | break; | |
649 | case Opt_order: | |
650 | if (strcmp(args[0].from, "relaxed") == 0) | |
651 | /* Ordered data semantics */ | |
652 | nilfs_clear_opt(sbi, STRICT_ORDER); | |
653 | else if (strcmp(args[0].from, "strict") == 0) | |
654 | /* Strict in-order semantics */ | |
655 | nilfs_set_opt(sbi, STRICT_ORDER); | |
656 | else | |
657 | return 0; | |
658 | break; | |
659 | case Opt_err_panic: | |
660 | nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC); | |
661 | break; | |
662 | case Opt_err_ro: | |
663 | nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO); | |
664 | break; | |
665 | case Opt_err_cont: | |
666 | nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT); | |
667 | break; | |
668 | case Opt_snapshot: | |
669 | if (match_int(&args[0], &option) || option <= 0) | |
670 | return 0; | |
671 | if (!(sb->s_flags & MS_RDONLY)) | |
672 | return 0; | |
673 | sbi->s_snapshot_cno = option; | |
674 | nilfs_set_opt(sbi, SNAPSHOT); | |
675 | break; | |
676 | default: | |
677 | printk(KERN_ERR | |
678 | "NILFS: Unrecognized mount option \"%s\"\n", p); | |
679 | return 0; | |
680 | } | |
681 | } | |
682 | return 1; | |
683 | } | |
684 | ||
685 | static inline void | |
686 | nilfs_set_default_options(struct nilfs_sb_info *sbi, | |
687 | struct nilfs_super_block *sbp) | |
688 | { | |
689 | sbi->s_mount_opt = | |
690 | NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER; | |
691 | } | |
692 | ||
693 | static int nilfs_setup_super(struct nilfs_sb_info *sbi) | |
694 | { | |
695 | struct the_nilfs *nilfs = sbi->s_nilfs; | |
e339ad31 | 696 | struct nilfs_super_block *sbp = nilfs->ns_sbp[0]; |
783f6184 RK |
697 | int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count); |
698 | int mnt_count = le16_to_cpu(sbp->s_mnt_count); | |
699 | ||
700 | /* nilfs->sem must be locked by the caller. */ | |
701 | if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) { | |
702 | printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); | |
703 | } else if (nilfs->ns_mount_state & NILFS_ERROR_FS) { | |
704 | printk(KERN_WARNING | |
705 | "NILFS warning: mounting fs with errors\n"); | |
706 | #if 0 | |
707 | } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { | |
708 | printk(KERN_WARNING | |
709 | "NILFS warning: maximal mount count reached\n"); | |
710 | #endif | |
711 | } | |
712 | if (!max_mnt_count) | |
713 | sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); | |
714 | ||
715 | sbp->s_mnt_count = cpu_to_le16(mnt_count + 1); | |
716 | sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS); | |
717 | sbp->s_mtime = cpu_to_le64(get_seconds()); | |
e339ad31 | 718 | return nilfs_commit_super(sbi, 1); |
783f6184 RK |
719 | } |
720 | ||
e339ad31 RK |
721 | struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb, |
722 | u64 pos, int blocksize, | |
723 | struct buffer_head **pbh) | |
783f6184 | 724 | { |
e339ad31 RK |
725 | unsigned long long sb_index = pos; |
726 | unsigned long offset; | |
783f6184 | 727 | |
e339ad31 | 728 | offset = do_div(sb_index, blocksize); |
783f6184 | 729 | *pbh = sb_bread(sb, sb_index); |
e339ad31 | 730 | if (!*pbh) |
783f6184 | 731 | return NULL; |
783f6184 RK |
732 | return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); |
733 | } | |
734 | ||
783f6184 RK |
735 | int nilfs_store_magic_and_option(struct super_block *sb, |
736 | struct nilfs_super_block *sbp, | |
737 | char *data) | |
738 | { | |
739 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | |
740 | ||
783f6184 RK |
741 | sb->s_magic = le16_to_cpu(sbp->s_magic); |
742 | ||
743 | /* FS independent flags */ | |
744 | #ifdef NILFS_ATIME_DISABLE | |
745 | sb->s_flags |= MS_NOATIME; | |
746 | #endif | |
747 | ||
783f6184 RK |
748 | nilfs_set_default_options(sbi, sbp); |
749 | ||
750 | sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid); | |
751 | sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid); | |
752 | sbi->s_interval = le32_to_cpu(sbp->s_c_interval); | |
753 | sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max); | |
754 | ||
e339ad31 | 755 | return !parse_options(data, sb) ? -EINVAL : 0 ; |
783f6184 RK |
756 | } |
757 | ||
758 | /** | |
759 | * nilfs_fill_super() - initialize a super block instance | |
760 | * @sb: super_block | |
761 | * @data: mount options | |
762 | * @silent: silent mode flag | |
763 | * @nilfs: the_nilfs struct | |
764 | * | |
765 | * This function is called exclusively by bd_mount_mutex. | |
766 | * So, the recovery process is protected from other simultaneous mounts. | |
767 | */ | |
768 | static int | |
769 | nilfs_fill_super(struct super_block *sb, void *data, int silent, | |
770 | struct the_nilfs *nilfs) | |
771 | { | |
772 | struct nilfs_sb_info *sbi; | |
773 | struct inode *root; | |
774 | __u64 cno; | |
775 | int err; | |
776 | ||
777 | sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); | |
778 | if (!sbi) | |
779 | return -ENOMEM; | |
780 | ||
781 | sb->s_fs_info = sbi; | |
782 | ||
783 | get_nilfs(nilfs); | |
784 | sbi->s_nilfs = nilfs; | |
785 | sbi->s_super = sb; | |
786 | ||
787 | err = init_nilfs(nilfs, sbi, (char *)data); | |
788 | if (err) | |
789 | goto failed_sbi; | |
790 | ||
791 | spin_lock_init(&sbi->s_inode_lock); | |
792 | INIT_LIST_HEAD(&sbi->s_dirty_files); | |
793 | INIT_LIST_HEAD(&sbi->s_list); | |
794 | ||
795 | /* | |
796 | * Following initialization is overlapped because | |
797 | * nilfs_sb_info structure has been cleared at the beginning. | |
798 | * But we reserve them to keep our interest and make ready | |
799 | * for the future change. | |
800 | */ | |
801 | get_random_bytes(&sbi->s_next_generation, | |
802 | sizeof(sbi->s_next_generation)); | |
803 | spin_lock_init(&sbi->s_next_gen_lock); | |
804 | ||
805 | sb->s_op = &nilfs_sops; | |
806 | sb->s_export_op = &nilfs_export_ops; | |
807 | sb->s_root = NULL; | |
61239230 | 808 | sb->s_time_gran = 1; |
783f6184 RK |
809 | |
810 | if (!nilfs_loaded(nilfs)) { | |
811 | err = load_nilfs(nilfs, sbi); | |
812 | if (err) | |
813 | goto failed_sbi; | |
814 | } | |
815 | cno = nilfs_last_cno(nilfs); | |
816 | ||
817 | if (sb->s_flags & MS_RDONLY) { | |
818 | if (nilfs_test_opt(sbi, SNAPSHOT)) { | |
1f5abe7e RK |
819 | err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, |
820 | sbi->s_snapshot_cno); | |
821 | if (err < 0) | |
822 | goto failed_sbi; | |
823 | if (!err) { | |
783f6184 RK |
824 | printk(KERN_ERR |
825 | "NILFS: The specified checkpoint is " | |
826 | "not a snapshot " | |
827 | "(checkpoint number=%llu).\n", | |
828 | (unsigned long long)sbi->s_snapshot_cno); | |
829 | err = -EINVAL; | |
830 | goto failed_sbi; | |
831 | } | |
832 | cno = sbi->s_snapshot_cno; | |
833 | } else | |
834 | /* Read-only mount */ | |
835 | sbi->s_snapshot_cno = cno; | |
836 | } | |
837 | ||
838 | err = nilfs_attach_checkpoint(sbi, cno); | |
839 | if (err) { | |
840 | printk(KERN_ERR "NILFS: error loading a checkpoint" | |
841 | " (checkpoint number=%llu).\n", (unsigned long long)cno); | |
842 | goto failed_sbi; | |
843 | } | |
844 | ||
845 | if (!(sb->s_flags & MS_RDONLY)) { | |
cece5520 | 846 | err = nilfs_attach_segment_constructor(sbi); |
783f6184 RK |
847 | if (err) |
848 | goto failed_checkpoint; | |
849 | } | |
850 | ||
851 | root = nilfs_iget(sb, NILFS_ROOT_INO); | |
852 | if (IS_ERR(root)) { | |
853 | printk(KERN_ERR "NILFS: get root inode failed\n"); | |
854 | err = PTR_ERR(root); | |
855 | goto failed_segctor; | |
856 | } | |
857 | if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { | |
858 | iput(root); | |
859 | printk(KERN_ERR "NILFS: corrupt root inode.\n"); | |
860 | err = -EINVAL; | |
861 | goto failed_segctor; | |
862 | } | |
863 | sb->s_root = d_alloc_root(root); | |
864 | if (!sb->s_root) { | |
865 | iput(root); | |
866 | printk(KERN_ERR "NILFS: get root dentry failed\n"); | |
867 | err = -ENOMEM; | |
868 | goto failed_segctor; | |
869 | } | |
870 | ||
871 | if (!(sb->s_flags & MS_RDONLY)) { | |
872 | down_write(&nilfs->ns_sem); | |
873 | nilfs_setup_super(sbi); | |
874 | up_write(&nilfs->ns_sem); | |
875 | } | |
876 | ||
877 | err = nilfs_mark_recovery_complete(sbi); | |
878 | if (unlikely(err)) { | |
879 | printk(KERN_ERR "NILFS: recovery failed.\n"); | |
880 | goto failed_root; | |
881 | } | |
882 | ||
883 | return 0; | |
884 | ||
885 | failed_root: | |
886 | dput(sb->s_root); | |
887 | sb->s_root = NULL; | |
888 | ||
889 | failed_segctor: | |
890 | nilfs_detach_segment_constructor(sbi); | |
891 | ||
892 | failed_checkpoint: | |
893 | nilfs_detach_checkpoint(sbi); | |
894 | ||
895 | failed_sbi: | |
896 | put_nilfs(nilfs); | |
897 | sb->s_fs_info = NULL; | |
898 | kfree(sbi); | |
899 | return err; | |
900 | } | |
901 | ||
902 | static int nilfs_remount(struct super_block *sb, int *flags, char *data) | |
903 | { | |
904 | struct nilfs_sb_info *sbi = NILFS_SB(sb); | |
905 | struct nilfs_super_block *sbp; | |
906 | struct the_nilfs *nilfs = sbi->s_nilfs; | |
907 | unsigned long old_sb_flags; | |
908 | struct nilfs_mount_options old_opts; | |
909 | int err; | |
910 | ||
337eb00a AIB |
911 | lock_kernel(); |
912 | ||
783f6184 RK |
913 | old_sb_flags = sb->s_flags; |
914 | old_opts.mount_opt = sbi->s_mount_opt; | |
915 | old_opts.snapshot_cno = sbi->s_snapshot_cno; | |
916 | ||
917 | if (!parse_options(data, sb)) { | |
918 | err = -EINVAL; | |
919 | goto restore_opts; | |
920 | } | |
921 | sb->s_flags = (sb->s_flags & ~MS_POSIXACL); | |
922 | ||
923 | if ((*flags & MS_RDONLY) && | |
924 | sbi->s_snapshot_cno != old_opts.snapshot_cno) { | |
925 | printk(KERN_WARNING "NILFS (device %s): couldn't " | |
926 | "remount to a different snapshot. \n", | |
927 | sb->s_id); | |
928 | err = -EINVAL; | |
929 | goto restore_opts; | |
930 | } | |
931 | ||
932 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) | |
933 | goto out; | |
934 | if (*flags & MS_RDONLY) { | |
935 | /* Shutting down the segment constructor */ | |
936 | nilfs_detach_segment_constructor(sbi); | |
937 | sb->s_flags |= MS_RDONLY; | |
938 | ||
939 | sbi->s_snapshot_cno = nilfs_last_cno(nilfs); | |
940 | /* nilfs_set_opt(sbi, SNAPSHOT); */ | |
941 | ||
942 | /* | |
943 | * Remounting a valid RW partition RDONLY, so set | |
944 | * the RDONLY flag and then mark the partition as valid again. | |
945 | */ | |
946 | down_write(&nilfs->ns_sem); | |
e339ad31 | 947 | sbp = nilfs->ns_sbp[0]; |
783f6184 RK |
948 | if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) && |
949 | (nilfs->ns_mount_state & NILFS_VALID_FS)) | |
950 | sbp->s_state = cpu_to_le16(nilfs->ns_mount_state); | |
951 | sbp->s_mtime = cpu_to_le64(get_seconds()); | |
e339ad31 | 952 | nilfs_commit_super(sbi, 1); |
783f6184 RK |
953 | up_write(&nilfs->ns_sem); |
954 | } else { | |
955 | /* | |
956 | * Mounting a RDONLY partition read-write, so reread and | |
957 | * store the current valid flag. (It may have been changed | |
958 | * by fsck since we originally mounted the partition.) | |
959 | */ | |
960 | down(&sb->s_bdev->bd_mount_sem); | |
961 | /* Check existing RW-mount */ | |
962 | if (test_exclusive_mount(sb->s_type, sb->s_bdev, 0)) { | |
963 | printk(KERN_WARNING "NILFS (device %s): couldn't " | |
964 | "remount because a RW-mount exists.\n", | |
965 | sb->s_id); | |
966 | err = -EBUSY; | |
967 | goto rw_remount_failed; | |
968 | } | |
969 | if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) { | |
970 | printk(KERN_WARNING "NILFS (device %s): couldn't " | |
971 | "remount because the current RO-mount is not " | |
972 | "the latest one.\n", | |
973 | sb->s_id); | |
974 | err = -EINVAL; | |
975 | goto rw_remount_failed; | |
976 | } | |
977 | sb->s_flags &= ~MS_RDONLY; | |
978 | nilfs_clear_opt(sbi, SNAPSHOT); | |
979 | sbi->s_snapshot_cno = 0; | |
980 | ||
cece5520 | 981 | err = nilfs_attach_segment_constructor(sbi); |
783f6184 RK |
982 | if (err) |
983 | goto rw_remount_failed; | |
984 | ||
985 | down_write(&nilfs->ns_sem); | |
986 | nilfs_setup_super(sbi); | |
987 | up_write(&nilfs->ns_sem); | |
988 | ||
989 | up(&sb->s_bdev->bd_mount_sem); | |
990 | } | |
991 | out: | |
337eb00a | 992 | unlock_kernel(); |
783f6184 RK |
993 | return 0; |
994 | ||
995 | rw_remount_failed: | |
996 | up(&sb->s_bdev->bd_mount_sem); | |
997 | restore_opts: | |
998 | sb->s_flags = old_sb_flags; | |
999 | sbi->s_mount_opt = old_opts.mount_opt; | |
1000 | sbi->s_snapshot_cno = old_opts.snapshot_cno; | |
337eb00a | 1001 | unlock_kernel(); |
783f6184 RK |
1002 | return err; |
1003 | } | |
1004 | ||
1005 | struct nilfs_super_data { | |
1006 | struct block_device *bdev; | |
1007 | __u64 cno; | |
1008 | int flags; | |
1009 | }; | |
1010 | ||
1011 | /** | |
1012 | * nilfs_identify - pre-read mount options needed to identify mount instance | |
1013 | * @data: mount options | |
1014 | * @sd: nilfs_super_data | |
1015 | */ | |
1016 | static int nilfs_identify(char *data, struct nilfs_super_data *sd) | |
1017 | { | |
1018 | char *p, *options = data; | |
1019 | substring_t args[MAX_OPT_ARGS]; | |
1020 | int option, token; | |
1021 | int ret = 0; | |
1022 | ||
1023 | do { | |
1024 | p = strsep(&options, ","); | |
1025 | if (p != NULL && *p) { | |
1026 | token = match_token(p, tokens, args); | |
1027 | if (token == Opt_snapshot) { | |
1028 | if (!(sd->flags & MS_RDONLY)) | |
1029 | ret++; | |
1030 | else { | |
1031 | ret = match_int(&args[0], &option); | |
1032 | if (!ret) { | |
1033 | if (option > 0) | |
1034 | sd->cno = option; | |
1035 | else | |
1036 | ret++; | |
1037 | } | |
1038 | } | |
1039 | } | |
1040 | if (ret) | |
1041 | printk(KERN_ERR | |
1042 | "NILFS: invalid mount option: %s\n", p); | |
1043 | } | |
1044 | if (!options) | |
1045 | break; | |
1046 | BUG_ON(options == data); | |
1047 | *(options - 1) = ','; | |
1048 | } while (!ret); | |
1049 | return ret; | |
1050 | } | |
1051 | ||
1052 | static int nilfs_set_bdev_super(struct super_block *s, void *data) | |
1053 | { | |
1054 | struct nilfs_super_data *sd = data; | |
1055 | ||
1056 | s->s_bdev = sd->bdev; | |
1057 | s->s_dev = s->s_bdev->bd_dev; | |
1058 | return 0; | |
1059 | } | |
1060 | ||
1061 | static int nilfs_test_bdev_super(struct super_block *s, void *data) | |
783f6184 RK |
1062 | { |
1063 | struct nilfs_super_data *sd = data; | |
1064 | int ret; | |
1065 | ||
1066 | if (s->s_bdev != sd->bdev) | |
1067 | return 0; | |
1068 | ||
1069 | if (!((s->s_flags | sd->flags) & MS_RDONLY)) | |
1070 | return 1; /* Reuse an old R/W-mode super_block */ | |
1071 | ||
1072 | if (s->s_flags & sd->flags & MS_RDONLY) { | |
1073 | if (down_read_trylock(&s->s_umount)) { | |
1074 | ret = s->s_root && | |
1075 | (sd->cno == NILFS_SB(s)->s_snapshot_cno); | |
1076 | up_read(&s->s_umount); | |
1077 | /* | |
1078 | * This path is locked with sb_lock by sget(). | |
1079 | * So, drop_super() causes deadlock. | |
1080 | */ | |
1081 | return ret; | |
1082 | } | |
1083 | } | |
1084 | return 0; | |
1085 | } | |
1086 | ||
1087 | static int | |
1088 | nilfs_get_sb(struct file_system_type *fs_type, int flags, | |
1089 | const char *dev_name, void *data, struct vfsmount *mnt) | |
1090 | { | |
1091 | struct nilfs_super_data sd; | |
33c8e57c RK |
1092 | struct super_block *s; |
1093 | struct the_nilfs *nilfs; | |
783f6184 RK |
1094 | int err, need_to_close = 1; |
1095 | ||
1096 | sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type); | |
1097 | if (IS_ERR(sd.bdev)) | |
1098 | return PTR_ERR(sd.bdev); | |
1099 | ||
1100 | /* | |
1101 | * To get mount instance using sget() vfs-routine, NILFS needs | |
1102 | * much more information than normal filesystems to identify mount | |
1103 | * instance. For snapshot mounts, not only a mount type (ro-mount | |
1104 | * or rw-mount) but also a checkpoint number is required. | |
1105 | * The results are passed in sget() using nilfs_super_data. | |
1106 | */ | |
1107 | sd.cno = 0; | |
1108 | sd.flags = flags; | |
1109 | if (nilfs_identify((char *)data, &sd)) { | |
1110 | err = -EINVAL; | |
1111 | goto failed; | |
1112 | } | |
1113 | ||
33c8e57c RK |
1114 | nilfs = find_or_create_nilfs(sd.bdev); |
1115 | if (!nilfs) { | |
1116 | err = -ENOMEM; | |
1117 | goto failed; | |
1118 | } | |
1119 | ||
783f6184 RK |
1120 | down(&sd.bdev->bd_mount_sem); |
1121 | if (!sd.cno && | |
1122 | (err = test_exclusive_mount(fs_type, sd.bdev, flags ^ MS_RDONLY))) { | |
1123 | err = (err < 0) ? : -EBUSY; | |
1124 | goto failed_unlock; | |
1125 | } | |
1126 | ||
1127 | /* | |
33c8e57c | 1128 | * Search specified snapshot or R/W mode super_block |
783f6184 | 1129 | */ |
33c8e57c RK |
1130 | if (!sd.cno) |
1131 | /* trying to get the latest checkpoint. */ | |
1132 | sd.cno = nilfs_last_cno(nilfs); | |
783f6184 | 1133 | |
33c8e57c RK |
1134 | s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd); |
1135 | if (IS_ERR(s)) { | |
1136 | err = PTR_ERR(s); | |
1137 | goto failed_unlock; | |
783f6184 RK |
1138 | } |
1139 | ||
1140 | if (!s->s_root) { | |
1141 | char b[BDEVNAME_SIZE]; | |
1142 | ||
33c8e57c | 1143 | /* New superblock instance created */ |
783f6184 RK |
1144 | s->s_flags = flags; |
1145 | strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id)); | |
1146 | sb_set_blocksize(s, block_size(sd.bdev)); | |
1147 | ||
1148 | err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs); | |
1149 | if (err) | |
1150 | goto cancel_new; | |
1151 | ||
1152 | s->s_flags |= MS_ACTIVE; | |
1153 | need_to_close = 0; | |
783f6184 RK |
1154 | } |
1155 | ||
1156 | up(&sd.bdev->bd_mount_sem); | |
1157 | put_nilfs(nilfs); | |
1158 | if (need_to_close) | |
1159 | close_bdev_exclusive(sd.bdev, flags); | |
1160 | simple_set_mnt(mnt, s); | |
1161 | return 0; | |
1162 | ||
783f6184 RK |
1163 | failed_unlock: |
1164 | up(&sd.bdev->bd_mount_sem); | |
33c8e57c | 1165 | put_nilfs(nilfs); |
783f6184 RK |
1166 | failed: |
1167 | close_bdev_exclusive(sd.bdev, flags); | |
1168 | ||
1169 | return err; | |
1170 | ||
1171 | cancel_new: | |
1172 | /* Abandoning the newly allocated superblock */ | |
1173 | up(&sd.bdev->bd_mount_sem); | |
33c8e57c | 1174 | put_nilfs(nilfs); |
783f6184 RK |
1175 | up_write(&s->s_umount); |
1176 | deactivate_super(s); | |
1177 | /* | |
1178 | * deactivate_super() invokes close_bdev_exclusive(). | |
1179 | * We must finish all post-cleaning before this call; | |
1180 | * put_nilfs() and unlocking bd_mount_sem need the block device. | |
1181 | */ | |
1182 | return err; | |
1183 | } | |
1184 | ||
1185 | static int nilfs_test_bdev_super3(struct super_block *s, void *data) | |
1186 | { | |
1187 | struct nilfs_super_data *sd = data; | |
1188 | int ret; | |
1189 | ||
1190 | if (s->s_bdev != sd->bdev) | |
1191 | return 0; | |
1192 | if (down_read_trylock(&s->s_umount)) { | |
1193 | ret = (s->s_flags & MS_RDONLY) && s->s_root && | |
1194 | nilfs_test_opt(NILFS_SB(s), SNAPSHOT); | |
1195 | up_read(&s->s_umount); | |
1196 | if (ret) | |
1197 | return 0; /* ignore snapshot mounts */ | |
1198 | } | |
1199 | return !((sd->flags ^ s->s_flags) & MS_RDONLY); | |
1200 | } | |
1201 | ||
1202 | static int __false_bdev_super(struct super_block *s, void *data) | |
1203 | { | |
1204 | #if 0 /* XXX: workaround for lock debug. This is not good idea */ | |
1205 | up_write(&s->s_umount); | |
1206 | #endif | |
1207 | return -EFAULT; | |
1208 | } | |
1209 | ||
1210 | /** | |
1211 | * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not. | |
1212 | * fs_type: filesystem type | |
1213 | * bdev: block device | |
1214 | * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount) | |
1215 | * res: pointer to an integer to store result | |
1216 | * | |
1217 | * This function must be called within a section protected by bd_mount_mutex. | |
1218 | */ | |
1219 | static int test_exclusive_mount(struct file_system_type *fs_type, | |
1220 | struct block_device *bdev, int flags) | |
1221 | { | |
1222 | struct super_block *s; | |
1223 | struct nilfs_super_data sd = { .flags = flags, .bdev = bdev }; | |
1224 | ||
1225 | s = sget(fs_type, nilfs_test_bdev_super3, __false_bdev_super, &sd); | |
1226 | if (IS_ERR(s)) { | |
1227 | if (PTR_ERR(s) != -EFAULT) | |
1228 | return PTR_ERR(s); | |
1229 | return 0; /* Not found */ | |
1230 | } | |
1231 | up_write(&s->s_umount); | |
1232 | deactivate_super(s); | |
1233 | return 1; /* Found */ | |
1234 | } | |
1235 | ||
1236 | struct file_system_type nilfs_fs_type = { | |
1237 | .owner = THIS_MODULE, | |
1238 | .name = "nilfs2", | |
1239 | .get_sb = nilfs_get_sb, | |
1240 | .kill_sb = kill_block_super, | |
1241 | .fs_flags = FS_REQUIRES_DEV, | |
1242 | }; | |
1243 | ||
1244 | static int __init init_nilfs_fs(void) | |
1245 | { | |
1246 | int err; | |
1247 | ||
1248 | err = nilfs_init_inode_cache(); | |
1249 | if (err) | |
1250 | goto failed; | |
1251 | ||
1252 | err = nilfs_init_transaction_cache(); | |
1253 | if (err) | |
1254 | goto failed_inode_cache; | |
1255 | ||
1256 | err = nilfs_init_segbuf_cache(); | |
1257 | if (err) | |
1258 | goto failed_transaction_cache; | |
1259 | ||
1260 | err = nilfs_btree_path_cache_init(); | |
1261 | if (err) | |
1262 | goto failed_segbuf_cache; | |
1263 | ||
1264 | err = register_filesystem(&nilfs_fs_type); | |
1265 | if (err) | |
1266 | goto failed_btree_path_cache; | |
1267 | ||
1268 | return 0; | |
1269 | ||
1270 | failed_btree_path_cache: | |
1271 | nilfs_btree_path_cache_destroy(); | |
1272 | ||
1273 | failed_segbuf_cache: | |
1274 | nilfs_destroy_segbuf_cache(); | |
1275 | ||
1276 | failed_transaction_cache: | |
1277 | nilfs_destroy_transaction_cache(); | |
1278 | ||
1279 | failed_inode_cache: | |
1280 | nilfs_destroy_inode_cache(); | |
1281 | ||
1282 | failed: | |
1283 | return err; | |
1284 | } | |
1285 | ||
1286 | static void __exit exit_nilfs_fs(void) | |
1287 | { | |
1288 | nilfs_destroy_segbuf_cache(); | |
1289 | nilfs_destroy_transaction_cache(); | |
1290 | nilfs_destroy_inode_cache(); | |
1291 | nilfs_btree_path_cache_destroy(); | |
1292 | unregister_filesystem(&nilfs_fs_type); | |
1293 | } | |
1294 | ||
1295 | module_init(init_nilfs_fs) | |
1296 | module_exit(exit_nilfs_fs) |