Root/
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/crc32.h> |
47 | #include <linux/vfs.h> |
48 | #include <linux/writeback.h> |
49 | #include <linux/seq_file.h> |
50 | #include <linux/mount.h> |
51 | #include "nilfs.h" |
52 | #include "export.h" |
53 | #include "mdt.h" |
54 | #include "alloc.h" |
55 | #include "btree.h" |
56 | #include "btnode.h" |
57 | #include "page.h" |
58 | #include "cpfile.h" |
59 | #include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */ |
60 | #include "ifile.h" |
61 | #include "dat.h" |
62 | #include "segment.h" |
63 | #include "segbuf.h" |
64 | |
65 | MODULE_AUTHOR("NTT Corp."); |
66 | MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem " |
67 | "(NILFS)"); |
68 | MODULE_LICENSE("GPL"); |
69 | |
70 | static struct kmem_cache *nilfs_inode_cachep; |
71 | struct kmem_cache *nilfs_transaction_cachep; |
72 | struct kmem_cache *nilfs_segbuf_cachep; |
73 | struct kmem_cache *nilfs_btree_path_cache; |
74 | |
75 | static int nilfs_setup_super(struct super_block *sb, int is_mount); |
76 | static int nilfs_remount(struct super_block *sb, int *flags, char *data); |
77 | |
78 | static void nilfs_set_error(struct super_block *sb) |
79 | { |
80 | struct the_nilfs *nilfs = sb->s_fs_info; |
81 | struct nilfs_super_block **sbp; |
82 | |
83 | down_write(&nilfs->ns_sem); |
84 | if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) { |
85 | nilfs->ns_mount_state |= NILFS_ERROR_FS; |
86 | sbp = nilfs_prepare_super(sb, 0); |
87 | if (likely(sbp)) { |
88 | sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS); |
89 | if (sbp[1]) |
90 | sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS); |
91 | nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); |
92 | } |
93 | } |
94 | up_write(&nilfs->ns_sem); |
95 | } |
96 | |
97 | /** |
98 | * nilfs_error() - report failure condition on a filesystem |
99 | * |
100 | * nilfs_error() sets an ERROR_FS flag on the superblock as well as |
101 | * reporting an error message. It should be called when NILFS detects |
102 | * incoherences or defects of meta data on disk. As for sustainable |
103 | * errors such as a single-shot I/O error, nilfs_warning() or the printk() |
104 | * function should be used instead. |
105 | * |
106 | * The segment constructor must not call this function because it can |
107 | * kill itself. |
108 | */ |
109 | void nilfs_error(struct super_block *sb, const char *function, |
110 | const char *fmt, ...) |
111 | { |
112 | struct the_nilfs *nilfs = sb->s_fs_info; |
113 | struct va_format vaf; |
114 | va_list args; |
115 | |
116 | va_start(args, fmt); |
117 | |
118 | vaf.fmt = fmt; |
119 | vaf.va = &args; |
120 | |
121 | printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n", |
122 | sb->s_id, function, &vaf); |
123 | |
124 | va_end(args); |
125 | |
126 | if (!(sb->s_flags & MS_RDONLY)) { |
127 | nilfs_set_error(sb); |
128 | |
129 | if (nilfs_test_opt(nilfs, ERRORS_RO)) { |
130 | printk(KERN_CRIT "Remounting filesystem read-only\n"); |
131 | sb->s_flags |= MS_RDONLY; |
132 | } |
133 | } |
134 | |
135 | if (nilfs_test_opt(nilfs, ERRORS_PANIC)) |
136 | panic("NILFS (device %s): panic forced after error\n", |
137 | sb->s_id); |
138 | } |
139 | |
140 | void nilfs_warning(struct super_block *sb, const char *function, |
141 | const char *fmt, ...) |
142 | { |
143 | struct va_format vaf; |
144 | va_list args; |
145 | |
146 | va_start(args, fmt); |
147 | |
148 | vaf.fmt = fmt; |
149 | vaf.va = &args; |
150 | |
151 | printk(KERN_WARNING "NILFS warning (device %s): %s: %pV\n", |
152 | sb->s_id, function, &vaf); |
153 | |
154 | va_end(args); |
155 | } |
156 | |
157 | |
158 | struct inode *nilfs_alloc_inode(struct super_block *sb) |
159 | { |
160 | struct nilfs_inode_info *ii; |
161 | |
162 | ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS); |
163 | if (!ii) |
164 | return NULL; |
165 | ii->i_bh = NULL; |
166 | ii->i_state = 0; |
167 | ii->i_cno = 0; |
168 | ii->vfs_inode.i_version = 1; |
169 | nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode, sb->s_bdi); |
170 | return &ii->vfs_inode; |
171 | } |
172 | |
173 | static void nilfs_i_callback(struct rcu_head *head) |
174 | { |
175 | struct inode *inode = container_of(head, struct inode, i_rcu); |
176 | struct nilfs_mdt_info *mdi = NILFS_MDT(inode); |
177 | |
178 | INIT_LIST_HEAD(&inode->i_dentry); |
179 | |
180 | if (mdi) { |
181 | kfree(mdi->mi_bgl); /* kfree(NULL) is safe */ |
182 | kfree(mdi); |
183 | } |
184 | kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); |
185 | } |
186 | |
187 | void nilfs_destroy_inode(struct inode *inode) |
188 | { |
189 | call_rcu(&inode->i_rcu, nilfs_i_callback); |
190 | } |
191 | |
192 | static int nilfs_sync_super(struct super_block *sb, int flag) |
193 | { |
194 | struct the_nilfs *nilfs = sb->s_fs_info; |
195 | int err; |
196 | |
197 | retry: |
198 | set_buffer_dirty(nilfs->ns_sbh[0]); |
199 | if (nilfs_test_opt(nilfs, BARRIER)) { |
200 | err = __sync_dirty_buffer(nilfs->ns_sbh[0], |
201 | WRITE_SYNC | WRITE_FLUSH_FUA); |
202 | } else { |
203 | err = sync_dirty_buffer(nilfs->ns_sbh[0]); |
204 | } |
205 | |
206 | if (unlikely(err)) { |
207 | printk(KERN_ERR |
208 | "NILFS: unable to write superblock (err=%d)\n", err); |
209 | if (err == -EIO && nilfs->ns_sbh[1]) { |
210 | /* |
211 | * sbp[0] points to newer log than sbp[1], |
212 | * so copy sbp[0] to sbp[1] to take over sbp[0]. |
213 | */ |
214 | memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0], |
215 | nilfs->ns_sbsize); |
216 | nilfs_fall_back_super_block(nilfs); |
217 | goto retry; |
218 | } |
219 | } else { |
220 | struct nilfs_super_block *sbp = nilfs->ns_sbp[0]; |
221 | |
222 | nilfs->ns_sbwcount++; |
223 | |
224 | /* |
225 | * The latest segment becomes trailable from the position |
226 | * written in superblock. |
227 | */ |
228 | clear_nilfs_discontinued(nilfs); |
229 | |
230 | /* update GC protection for recent segments */ |
231 | if (nilfs->ns_sbh[1]) { |
232 | if (flag == NILFS_SB_COMMIT_ALL) { |
233 | set_buffer_dirty(nilfs->ns_sbh[1]); |
234 | if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0) |
235 | goto out; |
236 | } |
237 | if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) < |
238 | le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno)) |
239 | sbp = nilfs->ns_sbp[1]; |
240 | } |
241 | |
242 | spin_lock(&nilfs->ns_last_segment_lock); |
243 | nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq); |
244 | spin_unlock(&nilfs->ns_last_segment_lock); |
245 | } |
246 | out: |
247 | return err; |
248 | } |
249 | |
250 | void nilfs_set_log_cursor(struct nilfs_super_block *sbp, |
251 | struct the_nilfs *nilfs) |
252 | { |
253 | sector_t nfreeblocks; |
254 | |
255 | /* nilfs->ns_sem must be locked by the caller. */ |
256 | nilfs_count_free_blocks(nilfs, &nfreeblocks); |
257 | sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks); |
258 | |
259 | spin_lock(&nilfs->ns_last_segment_lock); |
260 | sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq); |
261 | sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg); |
262 | sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno); |
263 | spin_unlock(&nilfs->ns_last_segment_lock); |
264 | } |
265 | |
266 | struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb, |
267 | int flip) |
268 | { |
269 | struct the_nilfs *nilfs = sb->s_fs_info; |
270 | struct nilfs_super_block **sbp = nilfs->ns_sbp; |
271 | |
272 | /* nilfs->ns_sem must be locked by the caller. */ |
273 | if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { |
274 | if (sbp[1] && |
275 | sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) { |
276 | memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); |
277 | } else { |
278 | printk(KERN_CRIT "NILFS: superblock broke on dev %s\n", |
279 | sb->s_id); |
280 | return NULL; |
281 | } |
282 | } else if (sbp[1] && |
283 | sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { |
284 | memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); |
285 | } |
286 | |
287 | if (flip && sbp[1]) |
288 | nilfs_swap_super_block(nilfs); |
289 | |
290 | return sbp; |
291 | } |
292 | |
293 | int nilfs_commit_super(struct super_block *sb, int flag) |
294 | { |
295 | struct the_nilfs *nilfs = sb->s_fs_info; |
296 | struct nilfs_super_block **sbp = nilfs->ns_sbp; |
297 | time_t t; |
298 | |
299 | /* nilfs->ns_sem must be locked by the caller. */ |
300 | t = get_seconds(); |
301 | nilfs->ns_sbwtime = t; |
302 | sbp[0]->s_wtime = cpu_to_le64(t); |
303 | sbp[0]->s_sum = 0; |
304 | sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, |
305 | (unsigned char *)sbp[0], |
306 | nilfs->ns_sbsize)); |
307 | if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) { |
308 | sbp[1]->s_wtime = sbp[0]->s_wtime; |
309 | sbp[1]->s_sum = 0; |
310 | sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, |
311 | (unsigned char *)sbp[1], |
312 | nilfs->ns_sbsize)); |
313 | } |
314 | clear_nilfs_sb_dirty(nilfs); |
315 | return nilfs_sync_super(sb, flag); |
316 | } |
317 | |
318 | /** |
319 | * nilfs_cleanup_super() - write filesystem state for cleanup |
320 | * @sb: super block instance to be unmounted or degraded to read-only |
321 | * |
322 | * This function restores state flags in the on-disk super block. |
323 | * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the |
324 | * filesystem was not clean previously. |
325 | */ |
326 | int nilfs_cleanup_super(struct super_block *sb) |
327 | { |
328 | struct the_nilfs *nilfs = sb->s_fs_info; |
329 | struct nilfs_super_block **sbp; |
330 | int flag = NILFS_SB_COMMIT; |
331 | int ret = -EIO; |
332 | |
333 | sbp = nilfs_prepare_super(sb, 0); |
334 | if (sbp) { |
335 | sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state); |
336 | nilfs_set_log_cursor(sbp[0], nilfs); |
337 | if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) { |
338 | /* |
339 | * make the "clean" flag also to the opposite |
340 | * super block if both super blocks point to |
341 | * the same checkpoint. |
342 | */ |
343 | sbp[1]->s_state = sbp[0]->s_state; |
344 | flag = NILFS_SB_COMMIT_ALL; |
345 | } |
346 | ret = nilfs_commit_super(sb, flag); |
347 | } |
348 | return ret; |
349 | } |
350 | |
351 | /** |
352 | * nilfs_move_2nd_super - relocate secondary super block |
353 | * @sb: super block instance |
354 | * @sb2off: new offset of the secondary super block (in bytes) |
355 | */ |
356 | static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off) |
357 | { |
358 | struct the_nilfs *nilfs = sb->s_fs_info; |
359 | struct buffer_head *nsbh; |
360 | struct nilfs_super_block *nsbp; |
361 | sector_t blocknr, newblocknr; |
362 | unsigned long offset; |
363 | int sb2i = -1; /* array index of the secondary superblock */ |
364 | int ret = 0; |
365 | |
366 | /* nilfs->ns_sem must be locked by the caller. */ |
367 | if (nilfs->ns_sbh[1] && |
368 | nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) { |
369 | sb2i = 1; |
370 | blocknr = nilfs->ns_sbh[1]->b_blocknr; |
371 | } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) { |
372 | sb2i = 0; |
373 | blocknr = nilfs->ns_sbh[0]->b_blocknr; |
374 | } |
375 | if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off) |
376 | goto out; /* super block location is unchanged */ |
377 | |
378 | /* Get new super block buffer */ |
379 | newblocknr = sb2off >> nilfs->ns_blocksize_bits; |
380 | offset = sb2off & (nilfs->ns_blocksize - 1); |
381 | nsbh = sb_getblk(sb, newblocknr); |
382 | if (!nsbh) { |
383 | printk(KERN_WARNING |
384 | "NILFS warning: unable to move secondary superblock " |
385 | "to block %llu\n", (unsigned long long)newblocknr); |
386 | ret = -EIO; |
387 | goto out; |
388 | } |
389 | nsbp = (void *)nsbh->b_data + offset; |
390 | memset(nsbp, 0, nilfs->ns_blocksize); |
391 | |
392 | if (sb2i >= 0) { |
393 | memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize); |
394 | brelse(nilfs->ns_sbh[sb2i]); |
395 | nilfs->ns_sbh[sb2i] = nsbh; |
396 | nilfs->ns_sbp[sb2i] = nsbp; |
397 | } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) { |
398 | /* secondary super block will be restored to index 1 */ |
399 | nilfs->ns_sbh[1] = nsbh; |
400 | nilfs->ns_sbp[1] = nsbp; |
401 | } else { |
402 | brelse(nsbh); |
403 | } |
404 | out: |
405 | return ret; |
406 | } |
407 | |
408 | /** |
409 | * nilfs_resize_fs - resize the filesystem |
410 | * @sb: super block instance |
411 | * @newsize: new size of the filesystem (in bytes) |
412 | */ |
413 | int nilfs_resize_fs(struct super_block *sb, __u64 newsize) |
414 | { |
415 | struct the_nilfs *nilfs = sb->s_fs_info; |
416 | struct nilfs_super_block **sbp; |
417 | __u64 devsize, newnsegs; |
418 | loff_t sb2off; |
419 | int ret; |
420 | |
421 | ret = -ERANGE; |
422 | devsize = i_size_read(sb->s_bdev->bd_inode); |
423 | if (newsize > devsize) |
424 | goto out; |
425 | |
426 | /* |
427 | * Write lock is required to protect some functions depending |
428 | * on the number of segments, the number of reserved segments, |
429 | * and so forth. |
430 | */ |
431 | down_write(&nilfs->ns_segctor_sem); |
432 | |
433 | sb2off = NILFS_SB2_OFFSET_BYTES(newsize); |
434 | newnsegs = sb2off >> nilfs->ns_blocksize_bits; |
435 | do_div(newnsegs, nilfs->ns_blocks_per_segment); |
436 | |
437 | ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs); |
438 | up_write(&nilfs->ns_segctor_sem); |
439 | if (ret < 0) |
440 | goto out; |
441 | |
442 | ret = nilfs_construct_segment(sb); |
443 | if (ret < 0) |
444 | goto out; |
445 | |
446 | down_write(&nilfs->ns_sem); |
447 | nilfs_move_2nd_super(sb, sb2off); |
448 | ret = -EIO; |
449 | sbp = nilfs_prepare_super(sb, 0); |
450 | if (likely(sbp)) { |
451 | nilfs_set_log_cursor(sbp[0], nilfs); |
452 | /* |
453 | * Drop NILFS_RESIZE_FS flag for compatibility with |
454 | * mount-time resize which may be implemented in a |
455 | * future release. |
456 | */ |
457 | sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & |
458 | ~NILFS_RESIZE_FS); |
459 | sbp[0]->s_dev_size = cpu_to_le64(newsize); |
460 | sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments); |
461 | if (sbp[1]) |
462 | memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); |
463 | ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); |
464 | } |
465 | up_write(&nilfs->ns_sem); |
466 | |
467 | /* |
468 | * Reset the range of allocatable segments last. This order |
469 | * is important in the case of expansion because the secondary |
470 | * superblock must be protected from log write until migration |
471 | * completes. |
472 | */ |
473 | if (!ret) |
474 | nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1); |
475 | out: |
476 | return ret; |
477 | } |
478 | |
479 | static void nilfs_put_super(struct super_block *sb) |
480 | { |
481 | struct the_nilfs *nilfs = sb->s_fs_info; |
482 | |
483 | nilfs_detach_log_writer(sb); |
484 | |
485 | if (!(sb->s_flags & MS_RDONLY)) { |
486 | down_write(&nilfs->ns_sem); |
487 | nilfs_cleanup_super(sb); |
488 | up_write(&nilfs->ns_sem); |
489 | } |
490 | |
491 | iput(nilfs->ns_sufile); |
492 | iput(nilfs->ns_cpfile); |
493 | iput(nilfs->ns_dat); |
494 | |
495 | destroy_nilfs(nilfs); |
496 | sb->s_fs_info = NULL; |
497 | } |
498 | |
499 | static int nilfs_sync_fs(struct super_block *sb, int wait) |
500 | { |
501 | struct the_nilfs *nilfs = sb->s_fs_info; |
502 | struct nilfs_super_block **sbp; |
503 | int err = 0; |
504 | |
505 | /* This function is called when super block should be written back */ |
506 | if (wait) |
507 | err = nilfs_construct_segment(sb); |
508 | |
509 | down_write(&nilfs->ns_sem); |
510 | if (nilfs_sb_dirty(nilfs)) { |
511 | sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs)); |
512 | if (likely(sbp)) { |
513 | nilfs_set_log_cursor(sbp[0], nilfs); |
514 | nilfs_commit_super(sb, NILFS_SB_COMMIT); |
515 | } |
516 | } |
517 | up_write(&nilfs->ns_sem); |
518 | |
519 | return err; |
520 | } |
521 | |
522 | int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt, |
523 | struct nilfs_root **rootp) |
524 | { |
525 | struct the_nilfs *nilfs = sb->s_fs_info; |
526 | struct nilfs_root *root; |
527 | struct nilfs_checkpoint *raw_cp; |
528 | struct buffer_head *bh_cp; |
529 | int err = -ENOMEM; |
530 | |
531 | root = nilfs_find_or_create_root( |
532 | nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno); |
533 | if (!root) |
534 | return err; |
535 | |
536 | if (root->ifile) |
537 | goto reuse; /* already attached checkpoint */ |
538 | |
539 | down_read(&nilfs->ns_segctor_sem); |
540 | err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, |
541 | &bh_cp); |
542 | up_read(&nilfs->ns_segctor_sem); |
543 | if (unlikely(err)) { |
544 | if (err == -ENOENT || err == -EINVAL) { |
545 | printk(KERN_ERR |
546 | "NILFS: Invalid checkpoint " |
547 | "(checkpoint number=%llu)\n", |
548 | (unsigned long long)cno); |
549 | err = -EINVAL; |
550 | } |
551 | goto failed; |
552 | } |
553 | |
554 | err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size, |
555 | &raw_cp->cp_ifile_inode, &root->ifile); |
556 | if (err) |
557 | goto failed_bh; |
558 | |
559 | atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count)); |
560 | atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count)); |
561 | |
562 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); |
563 | |
564 | reuse: |
565 | *rootp = root; |
566 | return 0; |
567 | |
568 | failed_bh: |
569 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); |
570 | failed: |
571 | nilfs_put_root(root); |
572 | |
573 | return err; |
574 | } |
575 | |
576 | static int nilfs_freeze(struct super_block *sb) |
577 | { |
578 | struct the_nilfs *nilfs = sb->s_fs_info; |
579 | int err; |
580 | |
581 | if (sb->s_flags & MS_RDONLY) |
582 | return 0; |
583 | |
584 | /* Mark super block clean */ |
585 | down_write(&nilfs->ns_sem); |
586 | err = nilfs_cleanup_super(sb); |
587 | up_write(&nilfs->ns_sem); |
588 | return err; |
589 | } |
590 | |
591 | static int nilfs_unfreeze(struct super_block *sb) |
592 | { |
593 | struct the_nilfs *nilfs = sb->s_fs_info; |
594 | |
595 | if (sb->s_flags & MS_RDONLY) |
596 | return 0; |
597 | |
598 | down_write(&nilfs->ns_sem); |
599 | nilfs_setup_super(sb, false); |
600 | up_write(&nilfs->ns_sem); |
601 | return 0; |
602 | } |
603 | |
604 | static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
605 | { |
606 | struct super_block *sb = dentry->d_sb; |
607 | struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root; |
608 | struct the_nilfs *nilfs = root->nilfs; |
609 | u64 id = huge_encode_dev(sb->s_bdev->bd_dev); |
610 | unsigned long long blocks; |
611 | unsigned long overhead; |
612 | unsigned long nrsvblocks; |
613 | sector_t nfreeblocks; |
614 | int err; |
615 | |
616 | /* |
617 | * Compute all of the segment blocks |
618 | * |
619 | * The blocks before first segment and after last segment |
620 | * are excluded. |
621 | */ |
622 | blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments |
623 | - nilfs->ns_first_data_block; |
624 | nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment; |
625 | |
626 | /* |
627 | * Compute the overhead |
628 | * |
629 | * When distributing meta data blocks outside segment structure, |
630 | * We must count them as the overhead. |
631 | */ |
632 | overhead = 0; |
633 | |
634 | err = nilfs_count_free_blocks(nilfs, &nfreeblocks); |
635 | if (unlikely(err)) |
636 | return err; |
637 | |
638 | buf->f_type = NILFS_SUPER_MAGIC; |
639 | buf->f_bsize = sb->s_blocksize; |
640 | buf->f_blocks = blocks - overhead; |
641 | buf->f_bfree = nfreeblocks; |
642 | buf->f_bavail = (buf->f_bfree >= nrsvblocks) ? |
643 | (buf->f_bfree - nrsvblocks) : 0; |
644 | buf->f_files = atomic_read(&root->inodes_count); |
645 | buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */ |
646 | buf->f_namelen = NILFS_NAME_LEN; |
647 | buf->f_fsid.val[0] = (u32)id; |
648 | buf->f_fsid.val[1] = (u32)(id >> 32); |
649 | |
650 | return 0; |
651 | } |
652 | |
653 | static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs) |
654 | { |
655 | struct super_block *sb = vfs->mnt_sb; |
656 | struct the_nilfs *nilfs = sb->s_fs_info; |
657 | struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root; |
658 | |
659 | if (!nilfs_test_opt(nilfs, BARRIER)) |
660 | seq_puts(seq, ",nobarrier"); |
661 | if (root->cno != NILFS_CPTREE_CURRENT_CNO) |
662 | seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno); |
663 | if (nilfs_test_opt(nilfs, ERRORS_PANIC)) |
664 | seq_puts(seq, ",errors=panic"); |
665 | if (nilfs_test_opt(nilfs, ERRORS_CONT)) |
666 | seq_puts(seq, ",errors=continue"); |
667 | if (nilfs_test_opt(nilfs, STRICT_ORDER)) |
668 | seq_puts(seq, ",order=strict"); |
669 | if (nilfs_test_opt(nilfs, NORECOVERY)) |
670 | seq_puts(seq, ",norecovery"); |
671 | if (nilfs_test_opt(nilfs, DISCARD)) |
672 | seq_puts(seq, ",discard"); |
673 | |
674 | return 0; |
675 | } |
676 | |
677 | static const struct super_operations nilfs_sops = { |
678 | .alloc_inode = nilfs_alloc_inode, |
679 | .destroy_inode = nilfs_destroy_inode, |
680 | .dirty_inode = nilfs_dirty_inode, |
681 | /* .write_inode = nilfs_write_inode, */ |
682 | /* .put_inode = nilfs_put_inode, */ |
683 | /* .drop_inode = nilfs_drop_inode, */ |
684 | .evict_inode = nilfs_evict_inode, |
685 | .put_super = nilfs_put_super, |
686 | /* .write_super = nilfs_write_super, */ |
687 | .sync_fs = nilfs_sync_fs, |
688 | .freeze_fs = nilfs_freeze, |
689 | .unfreeze_fs = nilfs_unfreeze, |
690 | /* .write_super_lockfs */ |
691 | /* .unlockfs */ |
692 | .statfs = nilfs_statfs, |
693 | .remount_fs = nilfs_remount, |
694 | /* .umount_begin */ |
695 | .show_options = nilfs_show_options |
696 | }; |
697 | |
698 | enum { |
699 | Opt_err_cont, Opt_err_panic, Opt_err_ro, |
700 | Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery, |
701 | Opt_discard, Opt_nodiscard, Opt_err, |
702 | }; |
703 | |
704 | static match_table_t tokens = { |
705 | {Opt_err_cont, "errors=continue"}, |
706 | {Opt_err_panic, "errors=panic"}, |
707 | {Opt_err_ro, "errors=remount-ro"}, |
708 | {Opt_barrier, "barrier"}, |
709 | {Opt_nobarrier, "nobarrier"}, |
710 | {Opt_snapshot, "cp=%u"}, |
711 | {Opt_order, "order=%s"}, |
712 | {Opt_norecovery, "norecovery"}, |
713 | {Opt_discard, "discard"}, |
714 | {Opt_nodiscard, "nodiscard"}, |
715 | {Opt_err, NULL} |
716 | }; |
717 | |
718 | static int parse_options(char *options, struct super_block *sb, int is_remount) |
719 | { |
720 | struct the_nilfs *nilfs = sb->s_fs_info; |
721 | char *p; |
722 | substring_t args[MAX_OPT_ARGS]; |
723 | |
724 | if (!options) |
725 | return 1; |
726 | |
727 | while ((p = strsep(&options, ",")) != NULL) { |
728 | int token; |
729 | if (!*p) |
730 | continue; |
731 | |
732 | token = match_token(p, tokens, args); |
733 | switch (token) { |
734 | case Opt_barrier: |
735 | nilfs_set_opt(nilfs, BARRIER); |
736 | break; |
737 | case Opt_nobarrier: |
738 | nilfs_clear_opt(nilfs, BARRIER); |
739 | break; |
740 | case Opt_order: |
741 | if (strcmp(args[0].from, "relaxed") == 0) |
742 | /* Ordered data semantics */ |
743 | nilfs_clear_opt(nilfs, STRICT_ORDER); |
744 | else if (strcmp(args[0].from, "strict") == 0) |
745 | /* Strict in-order semantics */ |
746 | nilfs_set_opt(nilfs, STRICT_ORDER); |
747 | else |
748 | return 0; |
749 | break; |
750 | case Opt_err_panic: |
751 | nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC); |
752 | break; |
753 | case Opt_err_ro: |
754 | nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO); |
755 | break; |
756 | case Opt_err_cont: |
757 | nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT); |
758 | break; |
759 | case Opt_snapshot: |
760 | if (is_remount) { |
761 | printk(KERN_ERR |
762 | "NILFS: \"%s\" option is invalid " |
763 | "for remount.\n", p); |
764 | return 0; |
765 | } |
766 | break; |
767 | case Opt_norecovery: |
768 | nilfs_set_opt(nilfs, NORECOVERY); |
769 | break; |
770 | case Opt_discard: |
771 | nilfs_set_opt(nilfs, DISCARD); |
772 | break; |
773 | case Opt_nodiscard: |
774 | nilfs_clear_opt(nilfs, DISCARD); |
775 | break; |
776 | default: |
777 | printk(KERN_ERR |
778 | "NILFS: Unrecognized mount option \"%s\"\n", p); |
779 | return 0; |
780 | } |
781 | } |
782 | return 1; |
783 | } |
784 | |
785 | static inline void |
786 | nilfs_set_default_options(struct super_block *sb, |
787 | struct nilfs_super_block *sbp) |
788 | { |
789 | struct the_nilfs *nilfs = sb->s_fs_info; |
790 | |
791 | nilfs->ns_mount_opt = |
792 | NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER; |
793 | } |
794 | |
795 | static int nilfs_setup_super(struct super_block *sb, int is_mount) |
796 | { |
797 | struct the_nilfs *nilfs = sb->s_fs_info; |
798 | struct nilfs_super_block **sbp; |
799 | int max_mnt_count; |
800 | int mnt_count; |
801 | |
802 | /* nilfs->ns_sem must be locked by the caller. */ |
803 | sbp = nilfs_prepare_super(sb, 0); |
804 | if (!sbp) |
805 | return -EIO; |
806 | |
807 | if (!is_mount) |
808 | goto skip_mount_setup; |
809 | |
810 | max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count); |
811 | mnt_count = le16_to_cpu(sbp[0]->s_mnt_count); |
812 | |
813 | if (nilfs->ns_mount_state & NILFS_ERROR_FS) { |
814 | printk(KERN_WARNING |
815 | "NILFS warning: mounting fs with errors\n"); |
816 | #if 0 |
817 | } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { |
818 | printk(KERN_WARNING |
819 | "NILFS warning: maximal mount count reached\n"); |
820 | #endif |
821 | } |
822 | if (!max_mnt_count) |
823 | sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); |
824 | |
825 | sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1); |
826 | sbp[0]->s_mtime = cpu_to_le64(get_seconds()); |
827 | |
828 | skip_mount_setup: |
829 | sbp[0]->s_state = |
830 | cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS); |
831 | /* synchronize sbp[1] with sbp[0] */ |
832 | if (sbp[1]) |
833 | memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); |
834 | return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); |
835 | } |
836 | |
837 | struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb, |
838 | u64 pos, int blocksize, |
839 | struct buffer_head **pbh) |
840 | { |
841 | unsigned long long sb_index = pos; |
842 | unsigned long offset; |
843 | |
844 | offset = do_div(sb_index, blocksize); |
845 | *pbh = sb_bread(sb, sb_index); |
846 | if (!*pbh) |
847 | return NULL; |
848 | return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); |
849 | } |
850 | |
851 | int nilfs_store_magic_and_option(struct super_block *sb, |
852 | struct nilfs_super_block *sbp, |
853 | char *data) |
854 | { |
855 | struct the_nilfs *nilfs = sb->s_fs_info; |
856 | |
857 | sb->s_magic = le16_to_cpu(sbp->s_magic); |
858 | |
859 | /* FS independent flags */ |
860 | #ifdef NILFS_ATIME_DISABLE |
861 | sb->s_flags |= MS_NOATIME; |
862 | #endif |
863 | |
864 | nilfs_set_default_options(sb, sbp); |
865 | |
866 | nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid); |
867 | nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid); |
868 | nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval); |
869 | nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max); |
870 | |
871 | return !parse_options(data, sb, 0) ? -EINVAL : 0 ; |
872 | } |
873 | |
874 | int nilfs_check_feature_compatibility(struct super_block *sb, |
875 | struct nilfs_super_block *sbp) |
876 | { |
877 | __u64 features; |
878 | |
879 | features = le64_to_cpu(sbp->s_feature_incompat) & |
880 | ~NILFS_FEATURE_INCOMPAT_SUPP; |
881 | if (features) { |
882 | printk(KERN_ERR "NILFS: couldn't mount because of unsupported " |
883 | "optional features (%llx)\n", |
884 | (unsigned long long)features); |
885 | return -EINVAL; |
886 | } |
887 | features = le64_to_cpu(sbp->s_feature_compat_ro) & |
888 | ~NILFS_FEATURE_COMPAT_RO_SUPP; |
889 | if (!(sb->s_flags & MS_RDONLY) && features) { |
890 | printk(KERN_ERR "NILFS: couldn't mount RDWR because of " |
891 | "unsupported optional features (%llx)\n", |
892 | (unsigned long long)features); |
893 | return -EINVAL; |
894 | } |
895 | return 0; |
896 | } |
897 | |
898 | static int nilfs_get_root_dentry(struct super_block *sb, |
899 | struct nilfs_root *root, |
900 | struct dentry **root_dentry) |
901 | { |
902 | struct inode *inode; |
903 | struct dentry *dentry; |
904 | int ret = 0; |
905 | |
906 | inode = nilfs_iget(sb, root, NILFS_ROOT_INO); |
907 | if (IS_ERR(inode)) { |
908 | printk(KERN_ERR "NILFS: get root inode failed\n"); |
909 | ret = PTR_ERR(inode); |
910 | goto out; |
911 | } |
912 | if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) { |
913 | iput(inode); |
914 | printk(KERN_ERR "NILFS: corrupt root inode.\n"); |
915 | ret = -EINVAL; |
916 | goto out; |
917 | } |
918 | |
919 | if (root->cno == NILFS_CPTREE_CURRENT_CNO) { |
920 | dentry = d_find_alias(inode); |
921 | if (!dentry) { |
922 | dentry = d_alloc_root(inode); |
923 | if (!dentry) { |
924 | iput(inode); |
925 | ret = -ENOMEM; |
926 | goto failed_dentry; |
927 | } |
928 | } else { |
929 | iput(inode); |
930 | } |
931 | } else { |
932 | dentry = d_obtain_alias(inode); |
933 | if (IS_ERR(dentry)) { |
934 | ret = PTR_ERR(dentry); |
935 | goto failed_dentry; |
936 | } |
937 | } |
938 | *root_dentry = dentry; |
939 | out: |
940 | return ret; |
941 | |
942 | failed_dentry: |
943 | printk(KERN_ERR "NILFS: get root dentry failed\n"); |
944 | goto out; |
945 | } |
946 | |
947 | static int nilfs_attach_snapshot(struct super_block *s, __u64 cno, |
948 | struct dentry **root_dentry) |
949 | { |
950 | struct the_nilfs *nilfs = s->s_fs_info; |
951 | struct nilfs_root *root; |
952 | int ret; |
953 | |
954 | down_read(&nilfs->ns_segctor_sem); |
955 | ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno); |
956 | up_read(&nilfs->ns_segctor_sem); |
957 | if (ret < 0) { |
958 | ret = (ret == -ENOENT) ? -EINVAL : ret; |
959 | goto out; |
960 | } else if (!ret) { |
961 | printk(KERN_ERR "NILFS: The specified checkpoint is " |
962 | "not a snapshot (checkpoint number=%llu).\n", |
963 | (unsigned long long)cno); |
964 | ret = -EINVAL; |
965 | goto out; |
966 | } |
967 | |
968 | ret = nilfs_attach_checkpoint(s, cno, false, &root); |
969 | if (ret) { |
970 | printk(KERN_ERR "NILFS: error loading snapshot " |
971 | "(checkpoint number=%llu).\n", |
972 | (unsigned long long)cno); |
973 | goto out; |
974 | } |
975 | ret = nilfs_get_root_dentry(s, root, root_dentry); |
976 | nilfs_put_root(root); |
977 | out: |
978 | return ret; |
979 | } |
980 | |
981 | static int nilfs_tree_was_touched(struct dentry *root_dentry) |
982 | { |
983 | return root_dentry->d_count > 1; |
984 | } |
985 | |
986 | /** |
987 | * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint |
988 | * @root_dentry: root dentry of the tree to be shrunk |
989 | * |
990 | * This function returns true if the tree was in-use. |
991 | */ |
992 | static int nilfs_try_to_shrink_tree(struct dentry *root_dentry) |
993 | { |
994 | if (have_submounts(root_dentry)) |
995 | return true; |
996 | shrink_dcache_parent(root_dentry); |
997 | return nilfs_tree_was_touched(root_dentry); |
998 | } |
999 | |
1000 | int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno) |
1001 | { |
1002 | struct the_nilfs *nilfs = sb->s_fs_info; |
1003 | struct nilfs_root *root; |
1004 | struct inode *inode; |
1005 | struct dentry *dentry; |
1006 | int ret; |
1007 | |
1008 | if (cno < 0 || cno > nilfs->ns_cno) |
1009 | return false; |
1010 | |
1011 | if (cno >= nilfs_last_cno(nilfs)) |
1012 | return true; /* protect recent checkpoints */ |
1013 | |
1014 | ret = false; |
1015 | root = nilfs_lookup_root(nilfs, cno); |
1016 | if (root) { |
1017 | inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO); |
1018 | if (inode) { |
1019 | dentry = d_find_alias(inode); |
1020 | if (dentry) { |
1021 | if (nilfs_tree_was_touched(dentry)) |
1022 | ret = nilfs_try_to_shrink_tree(dentry); |
1023 | dput(dentry); |
1024 | } |
1025 | iput(inode); |
1026 | } |
1027 | nilfs_put_root(root); |
1028 | } |
1029 | return ret; |
1030 | } |
1031 | |
1032 | /** |
1033 | * nilfs_fill_super() - initialize a super block instance |
1034 | * @sb: super_block |
1035 | * @data: mount options |
1036 | * @silent: silent mode flag |
1037 | * |
1038 | * This function is called exclusively by nilfs->ns_mount_mutex. |
1039 | * So, the recovery process is protected from other simultaneous mounts. |
1040 | */ |
1041 | static int |
1042 | nilfs_fill_super(struct super_block *sb, void *data, int silent) |
1043 | { |
1044 | struct the_nilfs *nilfs; |
1045 | struct nilfs_root *fsroot; |
1046 | struct backing_dev_info *bdi; |
1047 | __u64 cno; |
1048 | int err; |
1049 | |
1050 | nilfs = alloc_nilfs(sb->s_bdev); |
1051 | if (!nilfs) |
1052 | return -ENOMEM; |
1053 | |
1054 | sb->s_fs_info = nilfs; |
1055 | |
1056 | err = init_nilfs(nilfs, sb, (char *)data); |
1057 | if (err) |
1058 | goto failed_nilfs; |
1059 | |
1060 | sb->s_op = &nilfs_sops; |
1061 | sb->s_export_op = &nilfs_export_ops; |
1062 | sb->s_root = NULL; |
1063 | sb->s_time_gran = 1; |
1064 | |
1065 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; |
1066 | sb->s_bdi = bdi ? : &default_backing_dev_info; |
1067 | |
1068 | err = load_nilfs(nilfs, sb); |
1069 | if (err) |
1070 | goto failed_nilfs; |
1071 | |
1072 | cno = nilfs_last_cno(nilfs); |
1073 | err = nilfs_attach_checkpoint(sb, cno, true, &fsroot); |
1074 | if (err) { |
1075 | printk(KERN_ERR "NILFS: error loading last checkpoint " |
1076 | "(checkpoint number=%llu).\n", (unsigned long long)cno); |
1077 | goto failed_unload; |
1078 | } |
1079 | |
1080 | if (!(sb->s_flags & MS_RDONLY)) { |
1081 | err = nilfs_attach_log_writer(sb, fsroot); |
1082 | if (err) |
1083 | goto failed_checkpoint; |
1084 | } |
1085 | |
1086 | err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root); |
1087 | if (err) |
1088 | goto failed_segctor; |
1089 | |
1090 | nilfs_put_root(fsroot); |
1091 | |
1092 | if (!(sb->s_flags & MS_RDONLY)) { |
1093 | down_write(&nilfs->ns_sem); |
1094 | nilfs_setup_super(sb, true); |
1095 | up_write(&nilfs->ns_sem); |
1096 | } |
1097 | |
1098 | return 0; |
1099 | |
1100 | failed_segctor: |
1101 | nilfs_detach_log_writer(sb); |
1102 | |
1103 | failed_checkpoint: |
1104 | nilfs_put_root(fsroot); |
1105 | |
1106 | failed_unload: |
1107 | iput(nilfs->ns_sufile); |
1108 | iput(nilfs->ns_cpfile); |
1109 | iput(nilfs->ns_dat); |
1110 | |
1111 | failed_nilfs: |
1112 | destroy_nilfs(nilfs); |
1113 | return err; |
1114 | } |
1115 | |
1116 | static int nilfs_remount(struct super_block *sb, int *flags, char *data) |
1117 | { |
1118 | struct the_nilfs *nilfs = sb->s_fs_info; |
1119 | unsigned long old_sb_flags; |
1120 | unsigned long old_mount_opt; |
1121 | int err; |
1122 | |
1123 | old_sb_flags = sb->s_flags; |
1124 | old_mount_opt = nilfs->ns_mount_opt; |
1125 | |
1126 | if (!parse_options(data, sb, 1)) { |
1127 | err = -EINVAL; |
1128 | goto restore_opts; |
1129 | } |
1130 | sb->s_flags = (sb->s_flags & ~MS_POSIXACL); |
1131 | |
1132 | err = -EINVAL; |
1133 | |
1134 | if (!nilfs_valid_fs(nilfs)) { |
1135 | printk(KERN_WARNING "NILFS (device %s): couldn't " |
1136 | "remount because the filesystem is in an " |
1137 | "incomplete recovery state.\n", sb->s_id); |
1138 | goto restore_opts; |
1139 | } |
1140 | |
1141 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) |
1142 | goto out; |
1143 | if (*flags & MS_RDONLY) { |
1144 | /* Shutting down log writer */ |
1145 | nilfs_detach_log_writer(sb); |
1146 | sb->s_flags |= MS_RDONLY; |
1147 | |
1148 | /* |
1149 | * Remounting a valid RW partition RDONLY, so set |
1150 | * the RDONLY flag and then mark the partition as valid again. |
1151 | */ |
1152 | down_write(&nilfs->ns_sem); |
1153 | nilfs_cleanup_super(sb); |
1154 | up_write(&nilfs->ns_sem); |
1155 | } else { |
1156 | __u64 features; |
1157 | struct nilfs_root *root; |
1158 | |
1159 | /* |
1160 | * Mounting a RDONLY partition read-write, so reread and |
1161 | * store the current valid flag. (It may have been changed |
1162 | * by fsck since we originally mounted the partition.) |
1163 | */ |
1164 | down_read(&nilfs->ns_sem); |
1165 | features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & |
1166 | ~NILFS_FEATURE_COMPAT_RO_SUPP; |
1167 | up_read(&nilfs->ns_sem); |
1168 | if (features) { |
1169 | printk(KERN_WARNING "NILFS (device %s): couldn't " |
1170 | "remount RDWR because of unsupported optional " |
1171 | "features (%llx)\n", |
1172 | sb->s_id, (unsigned long long)features); |
1173 | err = -EROFS; |
1174 | goto restore_opts; |
1175 | } |
1176 | |
1177 | sb->s_flags &= ~MS_RDONLY; |
1178 | |
1179 | root = NILFS_I(sb->s_root->d_inode)->i_root; |
1180 | err = nilfs_attach_log_writer(sb, root); |
1181 | if (err) |
1182 | goto restore_opts; |
1183 | |
1184 | down_write(&nilfs->ns_sem); |
1185 | nilfs_setup_super(sb, true); |
1186 | up_write(&nilfs->ns_sem); |
1187 | } |
1188 | out: |
1189 | return 0; |
1190 | |
1191 | restore_opts: |
1192 | sb->s_flags = old_sb_flags; |
1193 | nilfs->ns_mount_opt = old_mount_opt; |
1194 | return err; |
1195 | } |
1196 | |
1197 | struct nilfs_super_data { |
1198 | struct block_device *bdev; |
1199 | __u64 cno; |
1200 | int flags; |
1201 | }; |
1202 | |
1203 | /** |
1204 | * nilfs_identify - pre-read mount options needed to identify mount instance |
1205 | * @data: mount options |
1206 | * @sd: nilfs_super_data |
1207 | */ |
1208 | static int nilfs_identify(char *data, struct nilfs_super_data *sd) |
1209 | { |
1210 | char *p, *options = data; |
1211 | substring_t args[MAX_OPT_ARGS]; |
1212 | int token; |
1213 | int ret = 0; |
1214 | |
1215 | do { |
1216 | p = strsep(&options, ","); |
1217 | if (p != NULL && *p) { |
1218 | token = match_token(p, tokens, args); |
1219 | if (token == Opt_snapshot) { |
1220 | if (!(sd->flags & MS_RDONLY)) { |
1221 | ret++; |
1222 | } else { |
1223 | sd->cno = simple_strtoull(args[0].from, |
1224 | NULL, 0); |
1225 | /* |
1226 | * No need to see the end pointer; |
1227 | * match_token() has done syntax |
1228 | * checking. |
1229 | */ |
1230 | if (sd->cno == 0) |
1231 | ret++; |
1232 | } |
1233 | } |
1234 | if (ret) |
1235 | printk(KERN_ERR |
1236 | "NILFS: invalid mount option: %s\n", p); |
1237 | } |
1238 | if (!options) |
1239 | break; |
1240 | BUG_ON(options == data); |
1241 | *(options - 1) = ','; |
1242 | } while (!ret); |
1243 | return ret; |
1244 | } |
1245 | |
1246 | static int nilfs_set_bdev_super(struct super_block *s, void *data) |
1247 | { |
1248 | s->s_bdev = data; |
1249 | s->s_dev = s->s_bdev->bd_dev; |
1250 | return 0; |
1251 | } |
1252 | |
1253 | static int nilfs_test_bdev_super(struct super_block *s, void *data) |
1254 | { |
1255 | return (void *)s->s_bdev == data; |
1256 | } |
1257 | |
1258 | static struct dentry * |
1259 | nilfs_mount(struct file_system_type *fs_type, int flags, |
1260 | const char *dev_name, void *data) |
1261 | { |
1262 | struct nilfs_super_data sd; |
1263 | struct super_block *s; |
1264 | fmode_t mode = FMODE_READ | FMODE_EXCL; |
1265 | struct dentry *root_dentry; |
1266 | int err, s_new = false; |
1267 | |
1268 | if (!(flags & MS_RDONLY)) |
1269 | mode |= FMODE_WRITE; |
1270 | |
1271 | sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type); |
1272 | if (IS_ERR(sd.bdev)) |
1273 | return ERR_CAST(sd.bdev); |
1274 | |
1275 | sd.cno = 0; |
1276 | sd.flags = flags; |
1277 | if (nilfs_identify((char *)data, &sd)) { |
1278 | err = -EINVAL; |
1279 | goto failed; |
1280 | } |
1281 | |
1282 | /* |
1283 | * once the super is inserted into the list by sget, s_umount |
1284 | * will protect the lockfs code from trying to start a snapshot |
1285 | * while we are mounting |
1286 | */ |
1287 | mutex_lock(&sd.bdev->bd_fsfreeze_mutex); |
1288 | if (sd.bdev->bd_fsfreeze_count > 0) { |
1289 | mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); |
1290 | err = -EBUSY; |
1291 | goto failed; |
1292 | } |
1293 | s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev); |
1294 | mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); |
1295 | if (IS_ERR(s)) { |
1296 | err = PTR_ERR(s); |
1297 | goto failed; |
1298 | } |
1299 | |
1300 | if (!s->s_root) { |
1301 | char b[BDEVNAME_SIZE]; |
1302 | |
1303 | s_new = true; |
1304 | |
1305 | /* New superblock instance created */ |
1306 | s->s_flags = flags; |
1307 | s->s_mode = mode; |
1308 | strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id)); |
1309 | sb_set_blocksize(s, block_size(sd.bdev)); |
1310 | |
1311 | err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0); |
1312 | if (err) |
1313 | goto failed_super; |
1314 | |
1315 | s->s_flags |= MS_ACTIVE; |
1316 | } else if (!sd.cno) { |
1317 | int busy = false; |
1318 | |
1319 | if (nilfs_tree_was_touched(s->s_root)) { |
1320 | busy = nilfs_try_to_shrink_tree(s->s_root); |
1321 | if (busy && (flags ^ s->s_flags) & MS_RDONLY) { |
1322 | printk(KERN_ERR "NILFS: the device already " |
1323 | "has a %s mount.\n", |
1324 | (s->s_flags & MS_RDONLY) ? |
1325 | "read-only" : "read/write"); |
1326 | err = -EBUSY; |
1327 | goto failed_super; |
1328 | } |
1329 | } |
1330 | if (!busy) { |
1331 | /* |
1332 | * Try remount to setup mount states if the current |
1333 | * tree is not mounted and only snapshots use this sb. |
1334 | */ |
1335 | err = nilfs_remount(s, &flags, data); |
1336 | if (err) |
1337 | goto failed_super; |
1338 | } |
1339 | } |
1340 | |
1341 | if (sd.cno) { |
1342 | err = nilfs_attach_snapshot(s, sd.cno, &root_dentry); |
1343 | if (err) |
1344 | goto failed_super; |
1345 | } else { |
1346 | root_dentry = dget(s->s_root); |
1347 | } |
1348 | |
1349 | if (!s_new) |
1350 | blkdev_put(sd.bdev, mode); |
1351 | |
1352 | return root_dentry; |
1353 | |
1354 | failed_super: |
1355 | deactivate_locked_super(s); |
1356 | |
1357 | failed: |
1358 | if (!s_new) |
1359 | blkdev_put(sd.bdev, mode); |
1360 | return ERR_PTR(err); |
1361 | } |
1362 | |
1363 | struct file_system_type nilfs_fs_type = { |
1364 | .owner = THIS_MODULE, |
1365 | .name = "nilfs2", |
1366 | .mount = nilfs_mount, |
1367 | .kill_sb = kill_block_super, |
1368 | .fs_flags = FS_REQUIRES_DEV, |
1369 | }; |
1370 | |
1371 | static void nilfs_inode_init_once(void *obj) |
1372 | { |
1373 | struct nilfs_inode_info *ii = obj; |
1374 | |
1375 | INIT_LIST_HEAD(&ii->i_dirty); |
1376 | #ifdef CONFIG_NILFS_XATTR |
1377 | init_rwsem(&ii->xattr_sem); |
1378 | #endif |
1379 | address_space_init_once(&ii->i_btnode_cache); |
1380 | ii->i_bmap = &ii->i_bmap_data; |
1381 | inode_init_once(&ii->vfs_inode); |
1382 | } |
1383 | |
1384 | static void nilfs_segbuf_init_once(void *obj) |
1385 | { |
1386 | memset(obj, 0, sizeof(struct nilfs_segment_buffer)); |
1387 | } |
1388 | |
1389 | static void nilfs_destroy_cachep(void) |
1390 | { |
1391 | if (nilfs_inode_cachep) |
1392 | kmem_cache_destroy(nilfs_inode_cachep); |
1393 | if (nilfs_transaction_cachep) |
1394 | kmem_cache_destroy(nilfs_transaction_cachep); |
1395 | if (nilfs_segbuf_cachep) |
1396 | kmem_cache_destroy(nilfs_segbuf_cachep); |
1397 | if (nilfs_btree_path_cache) |
1398 | kmem_cache_destroy(nilfs_btree_path_cache); |
1399 | } |
1400 | |
1401 | static int __init nilfs_init_cachep(void) |
1402 | { |
1403 | nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", |
1404 | sizeof(struct nilfs_inode_info), 0, |
1405 | SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once); |
1406 | if (!nilfs_inode_cachep) |
1407 | goto fail; |
1408 | |
1409 | nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache", |
1410 | sizeof(struct nilfs_transaction_info), 0, |
1411 | SLAB_RECLAIM_ACCOUNT, NULL); |
1412 | if (!nilfs_transaction_cachep) |
1413 | goto fail; |
1414 | |
1415 | nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache", |
1416 | sizeof(struct nilfs_segment_buffer), 0, |
1417 | SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once); |
1418 | if (!nilfs_segbuf_cachep) |
1419 | goto fail; |
1420 | |
1421 | nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache", |
1422 | sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX, |
1423 | 0, 0, NULL); |
1424 | if (!nilfs_btree_path_cache) |
1425 | goto fail; |
1426 | |
1427 | return 0; |
1428 | |
1429 | fail: |
1430 | nilfs_destroy_cachep(); |
1431 | return -ENOMEM; |
1432 | } |
1433 | |
1434 | static int __init init_nilfs_fs(void) |
1435 | { |
1436 | int err; |
1437 | |
1438 | err = nilfs_init_cachep(); |
1439 | if (err) |
1440 | goto fail; |
1441 | |
1442 | err = register_filesystem(&nilfs_fs_type); |
1443 | if (err) |
1444 | goto free_cachep; |
1445 | |
1446 | printk(KERN_INFO "NILFS version 2 loaded\n"); |
1447 | return 0; |
1448 | |
1449 | free_cachep: |
1450 | nilfs_destroy_cachep(); |
1451 | fail: |
1452 | return err; |
1453 | } |
1454 | |
1455 | static void __exit exit_nilfs_fs(void) |
1456 | { |
1457 | nilfs_destroy_cachep(); |
1458 | unregister_filesystem(&nilfs_fs_type); |
1459 | } |
1460 | |
1461 | module_init(init_nilfs_fs) |
1462 | module_exit(exit_nilfs_fs) |
1463 |
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Tags:
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v2.6.34-rc5
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