Root/
1 | /* |
2 | * the_nilfs.c - the_nilfs shared structure. |
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 | |
24 | #include <linux/buffer_head.h> |
25 | #include <linux/slab.h> |
26 | #include <linux/blkdev.h> |
27 | #include <linux/backing-dev.h> |
28 | #include <linux/crc32.h> |
29 | #include "nilfs.h" |
30 | #include "segment.h" |
31 | #include "alloc.h" |
32 | #include "cpfile.h" |
33 | #include "sufile.h" |
34 | #include "dat.h" |
35 | #include "segbuf.h" |
36 | |
37 | |
38 | static LIST_HEAD(nilfs_objects); |
39 | static DEFINE_SPINLOCK(nilfs_lock); |
40 | |
41 | void nilfs_set_last_segment(struct the_nilfs *nilfs, |
42 | sector_t start_blocknr, u64 seq, __u64 cno) |
43 | { |
44 | spin_lock(&nilfs->ns_last_segment_lock); |
45 | nilfs->ns_last_pseg = start_blocknr; |
46 | nilfs->ns_last_seq = seq; |
47 | nilfs->ns_last_cno = cno; |
48 | spin_unlock(&nilfs->ns_last_segment_lock); |
49 | } |
50 | |
51 | /** |
52 | * alloc_nilfs - allocate the_nilfs structure |
53 | * @bdev: block device to which the_nilfs is related |
54 | * |
55 | * alloc_nilfs() allocates memory for the_nilfs and |
56 | * initializes its reference count and locks. |
57 | * |
58 | * Return Value: On success, pointer to the_nilfs is returned. |
59 | * On error, NULL is returned. |
60 | */ |
61 | static struct the_nilfs *alloc_nilfs(struct block_device *bdev) |
62 | { |
63 | struct the_nilfs *nilfs; |
64 | |
65 | nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL); |
66 | if (!nilfs) |
67 | return NULL; |
68 | |
69 | nilfs->ns_bdev = bdev; |
70 | atomic_set(&nilfs->ns_count, 1); |
71 | atomic_set(&nilfs->ns_ndirtyblks, 0); |
72 | init_rwsem(&nilfs->ns_sem); |
73 | init_rwsem(&nilfs->ns_super_sem); |
74 | mutex_init(&nilfs->ns_mount_mutex); |
75 | init_rwsem(&nilfs->ns_writer_sem); |
76 | INIT_LIST_HEAD(&nilfs->ns_list); |
77 | INIT_LIST_HEAD(&nilfs->ns_supers); |
78 | spin_lock_init(&nilfs->ns_last_segment_lock); |
79 | nilfs->ns_gc_inodes_h = NULL; |
80 | init_rwsem(&nilfs->ns_segctor_sem); |
81 | |
82 | return nilfs; |
83 | } |
84 | |
85 | /** |
86 | * find_or_create_nilfs - find or create nilfs object |
87 | * @bdev: block device to which the_nilfs is related |
88 | * |
89 | * find_nilfs() looks up an existent nilfs object created on the |
90 | * device and gets the reference count of the object. If no nilfs object |
91 | * is found on the device, a new nilfs object is allocated. |
92 | * |
93 | * Return Value: On success, pointer to the nilfs object is returned. |
94 | * On error, NULL is returned. |
95 | */ |
96 | struct the_nilfs *find_or_create_nilfs(struct block_device *bdev) |
97 | { |
98 | struct the_nilfs *nilfs, *new = NULL; |
99 | |
100 | retry: |
101 | spin_lock(&nilfs_lock); |
102 | list_for_each_entry(nilfs, &nilfs_objects, ns_list) { |
103 | if (nilfs->ns_bdev == bdev) { |
104 | get_nilfs(nilfs); |
105 | spin_unlock(&nilfs_lock); |
106 | if (new) |
107 | put_nilfs(new); |
108 | return nilfs; /* existing object */ |
109 | } |
110 | } |
111 | if (new) { |
112 | list_add_tail(&new->ns_list, &nilfs_objects); |
113 | spin_unlock(&nilfs_lock); |
114 | return new; /* new object */ |
115 | } |
116 | spin_unlock(&nilfs_lock); |
117 | |
118 | new = alloc_nilfs(bdev); |
119 | if (new) |
120 | goto retry; |
121 | return NULL; /* insufficient memory */ |
122 | } |
123 | |
124 | /** |
125 | * put_nilfs - release a reference to the_nilfs |
126 | * @nilfs: the_nilfs structure to be released |
127 | * |
128 | * put_nilfs() decrements a reference counter of the_nilfs. |
129 | * If the reference count reaches zero, the_nilfs is freed. |
130 | */ |
131 | void put_nilfs(struct the_nilfs *nilfs) |
132 | { |
133 | spin_lock(&nilfs_lock); |
134 | if (!atomic_dec_and_test(&nilfs->ns_count)) { |
135 | spin_unlock(&nilfs_lock); |
136 | return; |
137 | } |
138 | list_del_init(&nilfs->ns_list); |
139 | spin_unlock(&nilfs_lock); |
140 | |
141 | /* |
142 | * Increment of ns_count never occurs below because the caller |
143 | * of get_nilfs() holds at least one reference to the_nilfs. |
144 | * Thus its exclusion control is not required here. |
145 | */ |
146 | |
147 | might_sleep(); |
148 | if (nilfs_loaded(nilfs)) { |
149 | nilfs_mdt_destroy(nilfs->ns_sufile); |
150 | nilfs_mdt_destroy(nilfs->ns_cpfile); |
151 | nilfs_mdt_destroy(nilfs->ns_dat); |
152 | nilfs_mdt_destroy(nilfs->ns_gc_dat); |
153 | } |
154 | if (nilfs_init(nilfs)) { |
155 | nilfs_destroy_gccache(nilfs); |
156 | brelse(nilfs->ns_sbh[0]); |
157 | brelse(nilfs->ns_sbh[1]); |
158 | } |
159 | kfree(nilfs); |
160 | } |
161 | |
162 | static int nilfs_load_super_root(struct the_nilfs *nilfs, |
163 | struct nilfs_sb_info *sbi, sector_t sr_block) |
164 | { |
165 | struct buffer_head *bh_sr; |
166 | struct nilfs_super_root *raw_sr; |
167 | struct nilfs_super_block **sbp = nilfs->ns_sbp; |
168 | unsigned dat_entry_size, segment_usage_size, checkpoint_size; |
169 | unsigned inode_size; |
170 | int err; |
171 | |
172 | err = nilfs_read_super_root_block(sbi->s_super, sr_block, &bh_sr, 1); |
173 | if (unlikely(err)) |
174 | return err; |
175 | |
176 | down_read(&nilfs->ns_sem); |
177 | dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size); |
178 | checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size); |
179 | segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size); |
180 | up_read(&nilfs->ns_sem); |
181 | |
182 | inode_size = nilfs->ns_inode_size; |
183 | |
184 | err = -ENOMEM; |
185 | nilfs->ns_dat = nilfs_dat_new(nilfs, dat_entry_size); |
186 | if (unlikely(!nilfs->ns_dat)) |
187 | goto failed; |
188 | |
189 | nilfs->ns_gc_dat = nilfs_dat_new(nilfs, dat_entry_size); |
190 | if (unlikely(!nilfs->ns_gc_dat)) |
191 | goto failed_dat; |
192 | |
193 | nilfs->ns_cpfile = nilfs_cpfile_new(nilfs, checkpoint_size); |
194 | if (unlikely(!nilfs->ns_cpfile)) |
195 | goto failed_gc_dat; |
196 | |
197 | nilfs->ns_sufile = nilfs_sufile_new(nilfs, segment_usage_size); |
198 | if (unlikely(!nilfs->ns_sufile)) |
199 | goto failed_cpfile; |
200 | |
201 | nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat); |
202 | |
203 | err = nilfs_dat_read(nilfs->ns_dat, (void *)bh_sr->b_data + |
204 | NILFS_SR_DAT_OFFSET(inode_size)); |
205 | if (unlikely(err)) |
206 | goto failed_sufile; |
207 | |
208 | err = nilfs_cpfile_read(nilfs->ns_cpfile, (void *)bh_sr->b_data + |
209 | NILFS_SR_CPFILE_OFFSET(inode_size)); |
210 | if (unlikely(err)) |
211 | goto failed_sufile; |
212 | |
213 | err = nilfs_sufile_read(nilfs->ns_sufile, (void *)bh_sr->b_data + |
214 | NILFS_SR_SUFILE_OFFSET(inode_size)); |
215 | if (unlikely(err)) |
216 | goto failed_sufile; |
217 | |
218 | raw_sr = (struct nilfs_super_root *)bh_sr->b_data; |
219 | nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime); |
220 | |
221 | failed: |
222 | brelse(bh_sr); |
223 | return err; |
224 | |
225 | failed_sufile: |
226 | nilfs_mdt_destroy(nilfs->ns_sufile); |
227 | |
228 | failed_cpfile: |
229 | nilfs_mdt_destroy(nilfs->ns_cpfile); |
230 | |
231 | failed_gc_dat: |
232 | nilfs_mdt_destroy(nilfs->ns_gc_dat); |
233 | |
234 | failed_dat: |
235 | nilfs_mdt_destroy(nilfs->ns_dat); |
236 | goto failed; |
237 | } |
238 | |
239 | static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri) |
240 | { |
241 | memset(ri, 0, sizeof(*ri)); |
242 | INIT_LIST_HEAD(&ri->ri_used_segments); |
243 | } |
244 | |
245 | static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri) |
246 | { |
247 | nilfs_dispose_segment_list(&ri->ri_used_segments); |
248 | } |
249 | |
250 | /** |
251 | * load_nilfs - load and recover the nilfs |
252 | * @nilfs: the_nilfs structure to be released |
253 | * @sbi: nilfs_sb_info used to recover past segment |
254 | * |
255 | * load_nilfs() searches and load the latest super root, |
256 | * attaches the last segment, and does recovery if needed. |
257 | * The caller must call this exclusively for simultaneous mounts. |
258 | */ |
259 | int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) |
260 | { |
261 | struct nilfs_recovery_info ri; |
262 | unsigned int s_flags = sbi->s_super->s_flags; |
263 | int really_read_only = bdev_read_only(nilfs->ns_bdev); |
264 | int valid_fs = nilfs_valid_fs(nilfs); |
265 | int err; |
266 | |
267 | if (nilfs_loaded(nilfs)) { |
268 | if (valid_fs || |
269 | ((s_flags & MS_RDONLY) && nilfs_test_opt(sbi, NORECOVERY))) |
270 | return 0; |
271 | printk(KERN_ERR "NILFS: the filesystem is in an incomplete " |
272 | "recovery state.\n"); |
273 | return -EINVAL; |
274 | } |
275 | |
276 | if (!valid_fs) { |
277 | printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); |
278 | if (s_flags & MS_RDONLY) { |
279 | printk(KERN_INFO "NILFS: INFO: recovery " |
280 | "required for readonly filesystem.\n"); |
281 | printk(KERN_INFO "NILFS: write access will " |
282 | "be enabled during recovery.\n"); |
283 | } |
284 | } |
285 | |
286 | nilfs_init_recovery_info(&ri); |
287 | |
288 | err = nilfs_search_super_root(nilfs, sbi, &ri); |
289 | if (unlikely(err)) { |
290 | printk(KERN_ERR "NILFS: error searching super root.\n"); |
291 | goto failed; |
292 | } |
293 | |
294 | err = nilfs_load_super_root(nilfs, sbi, ri.ri_super_root); |
295 | if (unlikely(err)) { |
296 | printk(KERN_ERR "NILFS: error loading super root.\n"); |
297 | goto failed; |
298 | } |
299 | |
300 | if (valid_fs) |
301 | goto skip_recovery; |
302 | |
303 | if (s_flags & MS_RDONLY) { |
304 | if (nilfs_test_opt(sbi, NORECOVERY)) { |
305 | printk(KERN_INFO "NILFS: norecovery option specified. " |
306 | "skipping roll-forward recovery\n"); |
307 | goto skip_recovery; |
308 | } |
309 | if (really_read_only) { |
310 | printk(KERN_ERR "NILFS: write access " |
311 | "unavailable, cannot proceed.\n"); |
312 | err = -EROFS; |
313 | goto failed_unload; |
314 | } |
315 | sbi->s_super->s_flags &= ~MS_RDONLY; |
316 | } else if (nilfs_test_opt(sbi, NORECOVERY)) { |
317 | printk(KERN_ERR "NILFS: recovery cancelled because norecovery " |
318 | "option was specified for a read/write mount\n"); |
319 | err = -EINVAL; |
320 | goto failed_unload; |
321 | } |
322 | |
323 | err = nilfs_recover_logical_segments(nilfs, sbi, &ri); |
324 | if (err) |
325 | goto failed_unload; |
326 | |
327 | down_write(&nilfs->ns_sem); |
328 | nilfs->ns_mount_state |= NILFS_VALID_FS; |
329 | nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state); |
330 | err = nilfs_commit_super(sbi, 1); |
331 | up_write(&nilfs->ns_sem); |
332 | |
333 | if (err) { |
334 | printk(KERN_ERR "NILFS: failed to update super block. " |
335 | "recovery unfinished.\n"); |
336 | goto failed_unload; |
337 | } |
338 | printk(KERN_INFO "NILFS: recovery complete.\n"); |
339 | |
340 | skip_recovery: |
341 | set_nilfs_loaded(nilfs); |
342 | nilfs_clear_recovery_info(&ri); |
343 | sbi->s_super->s_flags = s_flags; |
344 | return 0; |
345 | |
346 | failed_unload: |
347 | nilfs_mdt_destroy(nilfs->ns_cpfile); |
348 | nilfs_mdt_destroy(nilfs->ns_sufile); |
349 | nilfs_mdt_destroy(nilfs->ns_dat); |
350 | |
351 | failed: |
352 | nilfs_clear_recovery_info(&ri); |
353 | sbi->s_super->s_flags = s_flags; |
354 | return err; |
355 | } |
356 | |
357 | static unsigned long long nilfs_max_size(unsigned int blkbits) |
358 | { |
359 | unsigned int max_bits; |
360 | unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ |
361 | |
362 | max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ |
363 | if (max_bits < 64) |
364 | res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); |
365 | return res; |
366 | } |
367 | |
368 | static int nilfs_store_disk_layout(struct the_nilfs *nilfs, |
369 | struct nilfs_super_block *sbp) |
370 | { |
371 | if (le32_to_cpu(sbp->s_rev_level) != NILFS_CURRENT_REV) { |
372 | printk(KERN_ERR "NILFS: revision mismatch " |
373 | "(superblock rev.=%d.%d, current rev.=%d.%d). " |
374 | "Please check the version of mkfs.nilfs.\n", |
375 | le32_to_cpu(sbp->s_rev_level), |
376 | le16_to_cpu(sbp->s_minor_rev_level), |
377 | NILFS_CURRENT_REV, NILFS_MINOR_REV); |
378 | return -EINVAL; |
379 | } |
380 | nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); |
381 | if (nilfs->ns_sbsize > BLOCK_SIZE) |
382 | return -EINVAL; |
383 | |
384 | nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); |
385 | nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); |
386 | |
387 | nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); |
388 | if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { |
389 | printk(KERN_ERR "NILFS: too short segment.\n"); |
390 | return -EINVAL; |
391 | } |
392 | |
393 | nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); |
394 | nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments); |
395 | nilfs->ns_r_segments_percentage = |
396 | le32_to_cpu(sbp->s_r_segments_percentage); |
397 | nilfs->ns_nrsvsegs = |
398 | max_t(unsigned long, NILFS_MIN_NRSVSEGS, |
399 | DIV_ROUND_UP(nilfs->ns_nsegments * |
400 | nilfs->ns_r_segments_percentage, 100)); |
401 | nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); |
402 | return 0; |
403 | } |
404 | |
405 | static int nilfs_valid_sb(struct nilfs_super_block *sbp) |
406 | { |
407 | static unsigned char sum[4]; |
408 | const int sumoff = offsetof(struct nilfs_super_block, s_sum); |
409 | size_t bytes; |
410 | u32 crc; |
411 | |
412 | if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) |
413 | return 0; |
414 | bytes = le16_to_cpu(sbp->s_bytes); |
415 | if (bytes > BLOCK_SIZE) |
416 | return 0; |
417 | crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, |
418 | sumoff); |
419 | crc = crc32_le(crc, sum, 4); |
420 | crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, |
421 | bytes - sumoff - 4); |
422 | return crc == le32_to_cpu(sbp->s_sum); |
423 | } |
424 | |
425 | static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) |
426 | { |
427 | return offset < ((le64_to_cpu(sbp->s_nsegments) * |
428 | le32_to_cpu(sbp->s_blocks_per_segment)) << |
429 | (le32_to_cpu(sbp->s_log_block_size) + 10)); |
430 | } |
431 | |
432 | static void nilfs_release_super_block(struct the_nilfs *nilfs) |
433 | { |
434 | int i; |
435 | |
436 | for (i = 0; i < 2; i++) { |
437 | if (nilfs->ns_sbp[i]) { |
438 | brelse(nilfs->ns_sbh[i]); |
439 | nilfs->ns_sbh[i] = NULL; |
440 | nilfs->ns_sbp[i] = NULL; |
441 | } |
442 | } |
443 | } |
444 | |
445 | void nilfs_fall_back_super_block(struct the_nilfs *nilfs) |
446 | { |
447 | brelse(nilfs->ns_sbh[0]); |
448 | nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; |
449 | nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; |
450 | nilfs->ns_sbh[1] = NULL; |
451 | nilfs->ns_sbp[1] = NULL; |
452 | } |
453 | |
454 | void nilfs_swap_super_block(struct the_nilfs *nilfs) |
455 | { |
456 | struct buffer_head *tsbh = nilfs->ns_sbh[0]; |
457 | struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; |
458 | |
459 | nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; |
460 | nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; |
461 | nilfs->ns_sbh[1] = tsbh; |
462 | nilfs->ns_sbp[1] = tsbp; |
463 | } |
464 | |
465 | static int nilfs_load_super_block(struct the_nilfs *nilfs, |
466 | struct super_block *sb, int blocksize, |
467 | struct nilfs_super_block **sbpp) |
468 | { |
469 | struct nilfs_super_block **sbp = nilfs->ns_sbp; |
470 | struct buffer_head **sbh = nilfs->ns_sbh; |
471 | u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); |
472 | int valid[2], swp = 0; |
473 | |
474 | sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, |
475 | &sbh[0]); |
476 | sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); |
477 | |
478 | if (!sbp[0]) { |
479 | if (!sbp[1]) { |
480 | printk(KERN_ERR "NILFS: unable to read superblock\n"); |
481 | return -EIO; |
482 | } |
483 | printk(KERN_WARNING |
484 | "NILFS warning: unable to read primary superblock\n"); |
485 | } else if (!sbp[1]) |
486 | printk(KERN_WARNING |
487 | "NILFS warning: unable to read secondary superblock\n"); |
488 | |
489 | valid[0] = nilfs_valid_sb(sbp[0]); |
490 | valid[1] = nilfs_valid_sb(sbp[1]); |
491 | swp = valid[1] && |
492 | (!valid[0] || |
493 | le64_to_cpu(sbp[1]->s_wtime) > le64_to_cpu(sbp[0]->s_wtime)); |
494 | |
495 | if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { |
496 | brelse(sbh[1]); |
497 | sbh[1] = NULL; |
498 | sbp[1] = NULL; |
499 | swp = 0; |
500 | } |
501 | if (!valid[swp]) { |
502 | nilfs_release_super_block(nilfs); |
503 | printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n", |
504 | sb->s_id); |
505 | return -EINVAL; |
506 | } |
507 | |
508 | if (swp) { |
509 | printk(KERN_WARNING "NILFS warning: broken superblock. " |
510 | "using spare superblock.\n"); |
511 | nilfs_swap_super_block(nilfs); |
512 | } |
513 | |
514 | nilfs->ns_sbwtime[0] = le64_to_cpu(sbp[0]->s_wtime); |
515 | nilfs->ns_sbwtime[1] = valid[!swp] ? le64_to_cpu(sbp[1]->s_wtime) : 0; |
516 | nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); |
517 | *sbpp = sbp[0]; |
518 | return 0; |
519 | } |
520 | |
521 | /** |
522 | * init_nilfs - initialize a NILFS instance. |
523 | * @nilfs: the_nilfs structure |
524 | * @sbi: nilfs_sb_info |
525 | * @sb: super block |
526 | * @data: mount options |
527 | * |
528 | * init_nilfs() performs common initialization per block device (e.g. |
529 | * reading the super block, getting disk layout information, initializing |
530 | * shared fields in the_nilfs). It takes on some portion of the jobs |
531 | * typically done by a fill_super() routine. This division arises from |
532 | * the nature that multiple NILFS instances may be simultaneously |
533 | * mounted on a device. |
534 | * For multiple mounts on the same device, only the first mount |
535 | * invokes these tasks. |
536 | * |
537 | * Return Value: On success, 0 is returned. On error, a negative error |
538 | * code is returned. |
539 | */ |
540 | int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data) |
541 | { |
542 | struct super_block *sb = sbi->s_super; |
543 | struct nilfs_super_block *sbp; |
544 | struct backing_dev_info *bdi; |
545 | int blocksize; |
546 | int err; |
547 | |
548 | down_write(&nilfs->ns_sem); |
549 | if (nilfs_init(nilfs)) { |
550 | /* Load values from existing the_nilfs */ |
551 | sbp = nilfs->ns_sbp[0]; |
552 | err = nilfs_store_magic_and_option(sb, sbp, data); |
553 | if (err) |
554 | goto out; |
555 | |
556 | blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); |
557 | if (sb->s_blocksize != blocksize && |
558 | !sb_set_blocksize(sb, blocksize)) { |
559 | printk(KERN_ERR "NILFS: blocksize %d unfit to device\n", |
560 | blocksize); |
561 | err = -EINVAL; |
562 | } |
563 | sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); |
564 | goto out; |
565 | } |
566 | |
567 | blocksize = sb_min_blocksize(sb, BLOCK_SIZE); |
568 | if (!blocksize) { |
569 | printk(KERN_ERR "NILFS: unable to set blocksize\n"); |
570 | err = -EINVAL; |
571 | goto out; |
572 | } |
573 | err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); |
574 | if (err) |
575 | goto out; |
576 | |
577 | err = nilfs_store_magic_and_option(sb, sbp, data); |
578 | if (err) |
579 | goto failed_sbh; |
580 | |
581 | blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); |
582 | if (sb->s_blocksize != blocksize) { |
583 | int hw_blocksize = bdev_logical_block_size(sb->s_bdev); |
584 | |
585 | if (blocksize < hw_blocksize) { |
586 | printk(KERN_ERR |
587 | "NILFS: blocksize %d too small for device " |
588 | "(sector-size = %d).\n", |
589 | blocksize, hw_blocksize); |
590 | err = -EINVAL; |
591 | goto failed_sbh; |
592 | } |
593 | nilfs_release_super_block(nilfs); |
594 | sb_set_blocksize(sb, blocksize); |
595 | |
596 | err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); |
597 | if (err) |
598 | goto out; |
599 | /* not failed_sbh; sbh is released automatically |
600 | when reloading fails. */ |
601 | } |
602 | nilfs->ns_blocksize_bits = sb->s_blocksize_bits; |
603 | |
604 | err = nilfs_store_disk_layout(nilfs, sbp); |
605 | if (err) |
606 | goto failed_sbh; |
607 | |
608 | sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); |
609 | |
610 | nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); |
611 | |
612 | bdi = nilfs->ns_bdev->bd_inode->i_mapping->backing_dev_info; |
613 | nilfs->ns_bdi = bdi ? : &default_backing_dev_info; |
614 | |
615 | /* Finding last segment */ |
616 | nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg); |
617 | nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno); |
618 | nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq); |
619 | |
620 | nilfs->ns_seg_seq = nilfs->ns_last_seq; |
621 | nilfs->ns_segnum = |
622 | nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg); |
623 | nilfs->ns_cno = nilfs->ns_last_cno + 1; |
624 | if (nilfs->ns_segnum >= nilfs->ns_nsegments) { |
625 | printk(KERN_ERR "NILFS invalid last segment number.\n"); |
626 | err = -EINVAL; |
627 | goto failed_sbh; |
628 | } |
629 | /* Dummy values */ |
630 | nilfs->ns_free_segments_count = |
631 | nilfs->ns_nsegments - (nilfs->ns_segnum + 1); |
632 | |
633 | /* Initialize gcinode cache */ |
634 | err = nilfs_init_gccache(nilfs); |
635 | if (err) |
636 | goto failed_sbh; |
637 | |
638 | set_nilfs_init(nilfs); |
639 | err = 0; |
640 | out: |
641 | up_write(&nilfs->ns_sem); |
642 | return err; |
643 | |
644 | failed_sbh: |
645 | nilfs_release_super_block(nilfs); |
646 | goto out; |
647 | } |
648 | |
649 | int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, |
650 | size_t nsegs) |
651 | { |
652 | sector_t seg_start, seg_end; |
653 | sector_t start = 0, nblocks = 0; |
654 | unsigned int sects_per_block; |
655 | __u64 *sn; |
656 | int ret = 0; |
657 | |
658 | sects_per_block = (1 << nilfs->ns_blocksize_bits) / |
659 | bdev_logical_block_size(nilfs->ns_bdev); |
660 | for (sn = segnump; sn < segnump + nsegs; sn++) { |
661 | nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); |
662 | |
663 | if (!nblocks) { |
664 | start = seg_start; |
665 | nblocks = seg_end - seg_start + 1; |
666 | } else if (start + nblocks == seg_start) { |
667 | nblocks += seg_end - seg_start + 1; |
668 | } else { |
669 | ret = blkdev_issue_discard(nilfs->ns_bdev, |
670 | start * sects_per_block, |
671 | nblocks * sects_per_block, |
672 | GFP_NOFS, |
673 | DISCARD_FL_BARRIER); |
674 | if (ret < 0) |
675 | return ret; |
676 | nblocks = 0; |
677 | } |
678 | } |
679 | if (nblocks) |
680 | ret = blkdev_issue_discard(nilfs->ns_bdev, |
681 | start * sects_per_block, |
682 | nblocks * sects_per_block, |
683 | GFP_NOFS, DISCARD_FL_BARRIER); |
684 | return ret; |
685 | } |
686 | |
687 | int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) |
688 | { |
689 | struct inode *dat = nilfs_dat_inode(nilfs); |
690 | unsigned long ncleansegs; |
691 | |
692 | down_read(&NILFS_MDT(dat)->mi_sem); /* XXX */ |
693 | ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); |
694 | up_read(&NILFS_MDT(dat)->mi_sem); /* XXX */ |
695 | *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; |
696 | return 0; |
697 | } |
698 | |
699 | int nilfs_near_disk_full(struct the_nilfs *nilfs) |
700 | { |
701 | unsigned long ncleansegs, nincsegs; |
702 | |
703 | ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); |
704 | nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / |
705 | nilfs->ns_blocks_per_segment + 1; |
706 | |
707 | return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; |
708 | } |
709 | |
710 | /** |
711 | * nilfs_find_sbinfo - find existing nilfs_sb_info structure |
712 | * @nilfs: nilfs object |
713 | * @rw_mount: mount type (non-zero value for read/write mount) |
714 | * @cno: checkpoint number (zero for read-only mount) |
715 | * |
716 | * nilfs_find_sbinfo() returns the nilfs_sb_info structure which |
717 | * @rw_mount and @cno (in case of snapshots) matched. If no instance |
718 | * was found, NULL is returned. Although the super block instance can |
719 | * be unmounted after this function returns, the nilfs_sb_info struct |
720 | * is kept on memory until nilfs_put_sbinfo() is called. |
721 | */ |
722 | struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *nilfs, |
723 | int rw_mount, __u64 cno) |
724 | { |
725 | struct nilfs_sb_info *sbi; |
726 | |
727 | down_read(&nilfs->ns_super_sem); |
728 | /* |
729 | * The SNAPSHOT flag and sb->s_flags are supposed to be |
730 | * protected with nilfs->ns_super_sem. |
731 | */ |
732 | sbi = nilfs->ns_current; |
733 | if (rw_mount) { |
734 | if (sbi && !(sbi->s_super->s_flags & MS_RDONLY)) |
735 | goto found; /* read/write mount */ |
736 | else |
737 | goto out; |
738 | } else if (cno == 0) { |
739 | if (sbi && (sbi->s_super->s_flags & MS_RDONLY)) |
740 | goto found; /* read-only mount */ |
741 | else |
742 | goto out; |
743 | } |
744 | |
745 | list_for_each_entry(sbi, &nilfs->ns_supers, s_list) { |
746 | if (nilfs_test_opt(sbi, SNAPSHOT) && |
747 | sbi->s_snapshot_cno == cno) |
748 | goto found; /* snapshot mount */ |
749 | } |
750 | out: |
751 | up_read(&nilfs->ns_super_sem); |
752 | return NULL; |
753 | |
754 | found: |
755 | atomic_inc(&sbi->s_count); |
756 | up_read(&nilfs->ns_super_sem); |
757 | return sbi; |
758 | } |
759 | |
760 | int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno, |
761 | int snapshot_mount) |
762 | { |
763 | struct nilfs_sb_info *sbi; |
764 | int ret = 0; |
765 | |
766 | down_read(&nilfs->ns_super_sem); |
767 | if (cno == 0 || cno > nilfs->ns_cno) |
768 | goto out_unlock; |
769 | |
770 | list_for_each_entry(sbi, &nilfs->ns_supers, s_list) { |
771 | if (sbi->s_snapshot_cno == cno && |
772 | (!snapshot_mount || nilfs_test_opt(sbi, SNAPSHOT))) { |
773 | /* exclude read-only mounts */ |
774 | ret++; |
775 | break; |
776 | } |
777 | } |
778 | /* for protecting recent checkpoints */ |
779 | if (cno >= nilfs_last_cno(nilfs)) |
780 | ret++; |
781 | |
782 | out_unlock: |
783 | up_read(&nilfs->ns_super_sem); |
784 | return ret; |
785 | } |
786 |
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Tags:
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v2.6.34-rc5
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