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8a9d2191 RK |
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> | |
e339ad31 | 28 | #include <linux/crc32.h> |
8a9d2191 RK |
29 | #include "nilfs.h" |
30 | #include "segment.h" | |
31 | #include "alloc.h" | |
32 | #include "cpfile.h" | |
33 | #include "sufile.h" | |
34 | #include "dat.h" | |
8a9d2191 RK |
35 | #include "segbuf.h" |
36 | ||
33c8e57c RK |
37 | |
38 | static LIST_HEAD(nilfs_objects); | |
39 | static DEFINE_SPINLOCK(nilfs_lock); | |
40 | ||
8a9d2191 RK |
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 | */ | |
33c8e57c | 61 | static struct the_nilfs *alloc_nilfs(struct block_device *bdev) |
8a9d2191 RK |
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); | |
8a9d2191 RK |
71 | atomic_set(&nilfs->ns_ndirtyblks, 0); |
72 | init_rwsem(&nilfs->ns_sem); | |
e59399d0 | 73 | init_rwsem(&nilfs->ns_super_sem); |
aa7dfb89 | 74 | mutex_init(&nilfs->ns_mount_mutex); |
027d6404 | 75 | init_rwsem(&nilfs->ns_writer_sem); |
33c8e57c | 76 | INIT_LIST_HEAD(&nilfs->ns_list); |
8a9d2191 RK |
77 | INIT_LIST_HEAD(&nilfs->ns_supers); |
78 | spin_lock_init(&nilfs->ns_last_segment_lock); | |
79 | nilfs->ns_gc_inodes_h = NULL; | |
8a9d2191 | 80 | init_rwsem(&nilfs->ns_segctor_sem); |
8a9d2191 RK |
81 | |
82 | return nilfs; | |
83 | } | |
84 | ||
33c8e57c RK |
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 | ||
8a9d2191 RK |
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 | { | |
33c8e57c RK |
133 | spin_lock(&nilfs_lock); |
134 | if (!atomic_dec_and_test(&nilfs->ns_count)) { | |
135 | spin_unlock(&nilfs_lock); | |
8a9d2191 | 136 | return; |
33c8e57c RK |
137 | } |
138 | list_del_init(&nilfs->ns_list); | |
139 | spin_unlock(&nilfs_lock); | |
140 | ||
8a9d2191 | 141 | /* |
33c8e57c | 142 | * Increment of ns_count never occurs below because the caller |
8a9d2191 RK |
143 | * of get_nilfs() holds at least one reference to the_nilfs. |
144 | * Thus its exclusion control is not required here. | |
145 | */ | |
33c8e57c | 146 | |
8a9d2191 RK |
147 | might_sleep(); |
148 | if (nilfs_loaded(nilfs)) { | |
8a9d2191 | 149 | nilfs_mdt_destroy(nilfs->ns_sufile); |
8a9d2191 | 150 | nilfs_mdt_destroy(nilfs->ns_cpfile); |
8a9d2191 | 151 | nilfs_mdt_destroy(nilfs->ns_dat); |
8a9d2191 RK |
152 | nilfs_mdt_destroy(nilfs->ns_gc_dat); |
153 | } | |
154 | if (nilfs_init(nilfs)) { | |
155 | nilfs_destroy_gccache(nilfs); | |
e339ad31 RK |
156 | brelse(nilfs->ns_sbh[0]); |
157 | brelse(nilfs->ns_sbh[1]); | |
8a9d2191 RK |
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; | |
e339ad31 | 167 | struct nilfs_super_block **sbp = nilfs->ns_sbp; |
8a9d2191 RK |
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); | |
e339ad31 RK |
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); | |
8a9d2191 RK |
180 | up_read(&nilfs->ns_sem); |
181 | ||
182 | inode_size = nilfs->ns_inode_size; | |
183 | ||
184 | err = -ENOMEM; | |
79739565 | 185 | nilfs->ns_dat = nilfs_dat_new(nilfs, dat_entry_size); |
8a9d2191 RK |
186 | if (unlikely(!nilfs->ns_dat)) |
187 | goto failed; | |
188 | ||
79739565 | 189 | nilfs->ns_gc_dat = nilfs_dat_new(nilfs, dat_entry_size); |
8a9d2191 RK |
190 | if (unlikely(!nilfs->ns_gc_dat)) |
191 | goto failed_dat; | |
192 | ||
79739565 | 193 | nilfs->ns_cpfile = nilfs_cpfile_new(nilfs, checkpoint_size); |
8a9d2191 RK |
194 | if (unlikely(!nilfs->ns_cpfile)) |
195 | goto failed_gc_dat; | |
196 | ||
79739565 | 197 | nilfs->ns_sufile = nilfs_sufile_new(nilfs, segment_usage_size); |
8a9d2191 RK |
198 | if (unlikely(!nilfs->ns_sufile)) |
199 | goto failed_cpfile; | |
200 | ||
8a9d2191 | 201 | nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat); |
8a9d2191 | 202 | |
8707df38 RK |
203 | err = nilfs_dat_read(nilfs->ns_dat, (void *)bh_sr->b_data + |
204 | NILFS_SR_DAT_OFFSET(inode_size)); | |
8a9d2191 RK |
205 | if (unlikely(err)) |
206 | goto failed_sufile; | |
207 | ||
8707df38 RK |
208 | err = nilfs_cpfile_read(nilfs->ns_cpfile, (void *)bh_sr->b_data + |
209 | NILFS_SR_CPFILE_OFFSET(inode_size)); | |
8a9d2191 RK |
210 | if (unlikely(err)) |
211 | goto failed_sufile; | |
212 | ||
8707df38 RK |
213 | err = nilfs_sufile_read(nilfs->ns_sufile, (void *)bh_sr->b_data + |
214 | NILFS_SR_SUFILE_OFFSET(inode_size)); | |
8a9d2191 RK |
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 | unsigned valid_fs; | |
265 | int err = 0; | |
266 | ||
267 | nilfs_init_recovery_info(&ri); | |
268 | ||
269 | down_write(&nilfs->ns_sem); | |
270 | valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); | |
271 | up_write(&nilfs->ns_sem); | |
272 | ||
273 | if (!valid_fs && (s_flags & MS_RDONLY)) { | |
274 | printk(KERN_INFO "NILFS: INFO: recovery " | |
275 | "required for readonly filesystem.\n"); | |
276 | if (really_read_only) { | |
277 | printk(KERN_ERR "NILFS: write access " | |
278 | "unavailable, cannot proceed.\n"); | |
279 | err = -EROFS; | |
280 | goto failed; | |
281 | } | |
282 | printk(KERN_INFO "NILFS: write access will " | |
283 | "be enabled during recovery.\n"); | |
284 | sbi->s_super->s_flags &= ~MS_RDONLY; | |
285 | } | |
286 | ||
287 | err = nilfs_search_super_root(nilfs, sbi, &ri); | |
288 | if (unlikely(err)) { | |
289 | printk(KERN_ERR "NILFS: error searching super root.\n"); | |
290 | goto failed; | |
291 | } | |
292 | ||
293 | err = nilfs_load_super_root(nilfs, sbi, ri.ri_super_root); | |
294 | if (unlikely(err)) { | |
295 | printk(KERN_ERR "NILFS: error loading super root.\n"); | |
296 | goto failed; | |
297 | } | |
298 | ||
299 | if (!valid_fs) { | |
300 | err = nilfs_recover_logical_segments(nilfs, sbi, &ri); | |
301 | if (unlikely(err)) { | |
302 | nilfs_mdt_destroy(nilfs->ns_cpfile); | |
303 | nilfs_mdt_destroy(nilfs->ns_sufile); | |
304 | nilfs_mdt_destroy(nilfs->ns_dat); | |
305 | goto failed; | |
306 | } | |
e339ad31 RK |
307 | if (ri.ri_need_recovery == NILFS_RECOVERY_SR_UPDATED) |
308 | sbi->s_super->s_dirt = 1; | |
8a9d2191 RK |
309 | } |
310 | ||
311 | set_nilfs_loaded(nilfs); | |
312 | ||
313 | failed: | |
314 | nilfs_clear_recovery_info(&ri); | |
315 | sbi->s_super->s_flags = s_flags; | |
316 | return err; | |
317 | } | |
318 | ||
319 | static unsigned long long nilfs_max_size(unsigned int blkbits) | |
320 | { | |
321 | unsigned int max_bits; | |
322 | unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ | |
323 | ||
324 | max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ | |
325 | if (max_bits < 64) | |
326 | res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); | |
327 | return res; | |
328 | } | |
329 | ||
e339ad31 RK |
330 | static int nilfs_store_disk_layout(struct the_nilfs *nilfs, |
331 | struct nilfs_super_block *sbp) | |
8a9d2191 RK |
332 | { |
333 | if (le32_to_cpu(sbp->s_rev_level) != NILFS_CURRENT_REV) { | |
334 | printk(KERN_ERR "NILFS: revision mismatch " | |
335 | "(superblock rev.=%d.%d, current rev.=%d.%d). " | |
336 | "Please check the version of mkfs.nilfs.\n", | |
337 | le32_to_cpu(sbp->s_rev_level), | |
338 | le16_to_cpu(sbp->s_minor_rev_level), | |
339 | NILFS_CURRENT_REV, NILFS_MINOR_REV); | |
340 | return -EINVAL; | |
341 | } | |
e339ad31 RK |
342 | nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); |
343 | if (nilfs->ns_sbsize > BLOCK_SIZE) | |
344 | return -EINVAL; | |
345 | ||
8a9d2191 RK |
346 | nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); |
347 | nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); | |
348 | ||
349 | nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); | |
350 | if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { | |
351 | printk(KERN_ERR "NILFS: too short segment. \n"); | |
352 | return -EINVAL; | |
353 | } | |
354 | ||
355 | nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); | |
356 | nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments); | |
357 | nilfs->ns_r_segments_percentage = | |
358 | le32_to_cpu(sbp->s_r_segments_percentage); | |
359 | nilfs->ns_nrsvsegs = | |
360 | max_t(unsigned long, NILFS_MIN_NRSVSEGS, | |
361 | DIV_ROUND_UP(nilfs->ns_nsegments * | |
362 | nilfs->ns_r_segments_percentage, 100)); | |
363 | nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); | |
364 | return 0; | |
365 | } | |
366 | ||
e339ad31 RK |
367 | static int nilfs_valid_sb(struct nilfs_super_block *sbp) |
368 | { | |
369 | static unsigned char sum[4]; | |
370 | const int sumoff = offsetof(struct nilfs_super_block, s_sum); | |
371 | size_t bytes; | |
372 | u32 crc; | |
373 | ||
374 | if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) | |
375 | return 0; | |
376 | bytes = le16_to_cpu(sbp->s_bytes); | |
377 | if (bytes > BLOCK_SIZE) | |
378 | return 0; | |
379 | crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, | |
380 | sumoff); | |
381 | crc = crc32_le(crc, sum, 4); | |
382 | crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, | |
383 | bytes - sumoff - 4); | |
384 | return crc == le32_to_cpu(sbp->s_sum); | |
385 | } | |
386 | ||
387 | static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) | |
388 | { | |
389 | return offset < ((le64_to_cpu(sbp->s_nsegments) * | |
390 | le32_to_cpu(sbp->s_blocks_per_segment)) << | |
391 | (le32_to_cpu(sbp->s_log_block_size) + 10)); | |
392 | } | |
393 | ||
394 | static void nilfs_release_super_block(struct the_nilfs *nilfs) | |
395 | { | |
396 | int i; | |
397 | ||
398 | for (i = 0; i < 2; i++) { | |
399 | if (nilfs->ns_sbp[i]) { | |
400 | brelse(nilfs->ns_sbh[i]); | |
401 | nilfs->ns_sbh[i] = NULL; | |
402 | nilfs->ns_sbp[i] = NULL; | |
403 | } | |
404 | } | |
405 | } | |
406 | ||
407 | void nilfs_fall_back_super_block(struct the_nilfs *nilfs) | |
408 | { | |
409 | brelse(nilfs->ns_sbh[0]); | |
410 | nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; | |
411 | nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; | |
412 | nilfs->ns_sbh[1] = NULL; | |
413 | nilfs->ns_sbp[1] = NULL; | |
414 | } | |
415 | ||
416 | void nilfs_swap_super_block(struct the_nilfs *nilfs) | |
417 | { | |
418 | struct buffer_head *tsbh = nilfs->ns_sbh[0]; | |
419 | struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; | |
420 | ||
421 | nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; | |
422 | nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; | |
423 | nilfs->ns_sbh[1] = tsbh; | |
424 | nilfs->ns_sbp[1] = tsbp; | |
425 | } | |
426 | ||
427 | static int nilfs_load_super_block(struct the_nilfs *nilfs, | |
428 | struct super_block *sb, int blocksize, | |
429 | struct nilfs_super_block **sbpp) | |
430 | { | |
431 | struct nilfs_super_block **sbp = nilfs->ns_sbp; | |
432 | struct buffer_head **sbh = nilfs->ns_sbh; | |
433 | u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); | |
434 | int valid[2], swp = 0; | |
435 | ||
436 | sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, | |
437 | &sbh[0]); | |
438 | sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); | |
439 | ||
440 | if (!sbp[0]) { | |
441 | if (!sbp[1]) { | |
442 | printk(KERN_ERR "NILFS: unable to read superblock\n"); | |
443 | return -EIO; | |
444 | } | |
445 | printk(KERN_WARNING | |
446 | "NILFS warning: unable to read primary superblock\n"); | |
447 | } else if (!sbp[1]) | |
448 | printk(KERN_WARNING | |
449 | "NILFS warning: unable to read secondary superblock\n"); | |
450 | ||
451 | valid[0] = nilfs_valid_sb(sbp[0]); | |
452 | valid[1] = nilfs_valid_sb(sbp[1]); | |
453 | swp = valid[1] && | |
454 | (!valid[0] || | |
455 | le64_to_cpu(sbp[1]->s_wtime) > le64_to_cpu(sbp[0]->s_wtime)); | |
456 | ||
457 | if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { | |
458 | brelse(sbh[1]); | |
459 | sbh[1] = NULL; | |
460 | sbp[1] = NULL; | |
461 | swp = 0; | |
462 | } | |
463 | if (!valid[swp]) { | |
464 | nilfs_release_super_block(nilfs); | |
465 | printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n", | |
466 | sb->s_id); | |
467 | return -EINVAL; | |
468 | } | |
469 | ||
470 | if (swp) { | |
471 | printk(KERN_WARNING "NILFS warning: broken superblock. " | |
472 | "using spare superblock.\n"); | |
473 | nilfs_swap_super_block(nilfs); | |
474 | } | |
475 | ||
476 | nilfs->ns_sbwtime[0] = le64_to_cpu(sbp[0]->s_wtime); | |
477 | nilfs->ns_sbwtime[1] = valid[!swp] ? le64_to_cpu(sbp[1]->s_wtime) : 0; | |
478 | nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); | |
479 | *sbpp = sbp[0]; | |
480 | return 0; | |
481 | } | |
482 | ||
8a9d2191 RK |
483 | /** |
484 | * init_nilfs - initialize a NILFS instance. | |
485 | * @nilfs: the_nilfs structure | |
486 | * @sbi: nilfs_sb_info | |
487 | * @sb: super block | |
488 | * @data: mount options | |
489 | * | |
490 | * init_nilfs() performs common initialization per block device (e.g. | |
491 | * reading the super block, getting disk layout information, initializing | |
492 | * shared fields in the_nilfs). It takes on some portion of the jobs | |
493 | * typically done by a fill_super() routine. This division arises from | |
494 | * the nature that multiple NILFS instances may be simultaneously | |
495 | * mounted on a device. | |
496 | * For multiple mounts on the same device, only the first mount | |
497 | * invokes these tasks. | |
498 | * | |
499 | * Return Value: On success, 0 is returned. On error, a negative error | |
500 | * code is returned. | |
501 | */ | |
502 | int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data) | |
503 | { | |
504 | struct super_block *sb = sbi->s_super; | |
8a9d2191 RK |
505 | struct nilfs_super_block *sbp; |
506 | struct backing_dev_info *bdi; | |
507 | int blocksize; | |
e339ad31 | 508 | int err; |
8a9d2191 RK |
509 | |
510 | down_write(&nilfs->ns_sem); | |
511 | if (nilfs_init(nilfs)) { | |
512 | /* Load values from existing the_nilfs */ | |
e339ad31 | 513 | sbp = nilfs->ns_sbp[0]; |
8a9d2191 RK |
514 | err = nilfs_store_magic_and_option(sb, sbp, data); |
515 | if (err) | |
516 | goto out; | |
517 | ||
518 | blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); | |
519 | if (sb->s_blocksize != blocksize && | |
520 | !sb_set_blocksize(sb, blocksize)) { | |
521 | printk(KERN_ERR "NILFS: blocksize %d unfit to device\n", | |
522 | blocksize); | |
523 | err = -EINVAL; | |
524 | } | |
525 | sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); | |
526 | goto out; | |
527 | } | |
528 | ||
e339ad31 RK |
529 | blocksize = sb_min_blocksize(sb, BLOCK_SIZE); |
530 | if (!blocksize) { | |
531 | printk(KERN_ERR "NILFS: unable to set blocksize\n"); | |
8a9d2191 RK |
532 | err = -EINVAL; |
533 | goto out; | |
534 | } | |
e339ad31 RK |
535 | err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); |
536 | if (err) | |
537 | goto out; | |
538 | ||
8a9d2191 RK |
539 | err = nilfs_store_magic_and_option(sb, sbp, data); |
540 | if (err) | |
541 | goto failed_sbh; | |
542 | ||
543 | blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); | |
544 | if (sb->s_blocksize != blocksize) { | |
e1defc4f | 545 | int hw_blocksize = bdev_logical_block_size(sb->s_bdev); |
e339ad31 RK |
546 | |
547 | if (blocksize < hw_blocksize) { | |
548 | printk(KERN_ERR | |
549 | "NILFS: blocksize %d too small for device " | |
550 | "(sector-size = %d).\n", | |
551 | blocksize, hw_blocksize); | |
8a9d2191 | 552 | err = -EINVAL; |
e339ad31 RK |
553 | goto failed_sbh; |
554 | } | |
555 | nilfs_release_super_block(nilfs); | |
556 | sb_set_blocksize(sb, blocksize); | |
557 | ||
558 | err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); | |
559 | if (err) | |
8a9d2191 RK |
560 | goto out; |
561 | /* not failed_sbh; sbh is released automatically | |
562 | when reloading fails. */ | |
8a9d2191 RK |
563 | } |
564 | nilfs->ns_blocksize_bits = sb->s_blocksize_bits; | |
565 | ||
e339ad31 | 566 | err = nilfs_store_disk_layout(nilfs, sbp); |
8a9d2191 RK |
567 | if (err) |
568 | goto failed_sbh; | |
569 | ||
570 | sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); | |
571 | ||
572 | nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); | |
8a9d2191 | 573 | |
2c96ce9f | 574 | bdi = nilfs->ns_bdev->bd_inode->i_mapping->backing_dev_info; |
8a9d2191 RK |
575 | nilfs->ns_bdi = bdi ? : &default_backing_dev_info; |
576 | ||
577 | /* Finding last segment */ | |
578 | nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg); | |
579 | nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno); | |
580 | nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq); | |
581 | ||
582 | nilfs->ns_seg_seq = nilfs->ns_last_seq; | |
583 | nilfs->ns_segnum = | |
584 | nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg); | |
585 | nilfs->ns_cno = nilfs->ns_last_cno + 1; | |
586 | if (nilfs->ns_segnum >= nilfs->ns_nsegments) { | |
587 | printk(KERN_ERR "NILFS invalid last segment number.\n"); | |
588 | err = -EINVAL; | |
589 | goto failed_sbh; | |
590 | } | |
591 | /* Dummy values */ | |
592 | nilfs->ns_free_segments_count = | |
593 | nilfs->ns_nsegments - (nilfs->ns_segnum + 1); | |
594 | ||
595 | /* Initialize gcinode cache */ | |
596 | err = nilfs_init_gccache(nilfs); | |
597 | if (err) | |
598 | goto failed_sbh; | |
599 | ||
600 | set_nilfs_init(nilfs); | |
601 | err = 0; | |
602 | out: | |
603 | up_write(&nilfs->ns_sem); | |
604 | return err; | |
605 | ||
606 | failed_sbh: | |
e339ad31 | 607 | nilfs_release_super_block(nilfs); |
8a9d2191 RK |
608 | goto out; |
609 | } | |
610 | ||
611 | int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) | |
612 | { | |
613 | struct inode *dat = nilfs_dat_inode(nilfs); | |
614 | unsigned long ncleansegs; | |
8a9d2191 RK |
615 | |
616 | down_read(&NILFS_MDT(dat)->mi_sem); /* XXX */ | |
ef7d4757 | 617 | ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); |
8a9d2191 | 618 | up_read(&NILFS_MDT(dat)->mi_sem); /* XXX */ |
ef7d4757 RK |
619 | *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; |
620 | return 0; | |
8a9d2191 RK |
621 | } |
622 | ||
8a9d2191 RK |
623 | int nilfs_near_disk_full(struct the_nilfs *nilfs) |
624 | { | |
8a9d2191 | 625 | unsigned long ncleansegs, nincsegs; |
ef7d4757 RK |
626 | |
627 | ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); | |
628 | nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / | |
629 | nilfs->ns_blocks_per_segment + 1; | |
630 | ||
631 | return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; | |
8a9d2191 RK |
632 | } |
633 | ||
6dd47406 RK |
634 | /** |
635 | * nilfs_find_sbinfo - find existing nilfs_sb_info structure | |
636 | * @nilfs: nilfs object | |
637 | * @rw_mount: mount type (non-zero value for read/write mount) | |
638 | * @cno: checkpoint number (zero for read-only mount) | |
639 | * | |
640 | * nilfs_find_sbinfo() returns the nilfs_sb_info structure which | |
641 | * @rw_mount and @cno (in case of snapshots) matched. If no instance | |
642 | * was found, NULL is returned. Although the super block instance can | |
643 | * be unmounted after this function returns, the nilfs_sb_info struct | |
644 | * is kept on memory until nilfs_put_sbinfo() is called. | |
645 | */ | |
646 | struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *nilfs, | |
647 | int rw_mount, __u64 cno) | |
648 | { | |
649 | struct nilfs_sb_info *sbi; | |
650 | ||
e59399d0 | 651 | down_read(&nilfs->ns_super_sem); |
6dd47406 RK |
652 | /* |
653 | * The SNAPSHOT flag and sb->s_flags are supposed to be | |
e59399d0 | 654 | * protected with nilfs->ns_super_sem. |
6dd47406 RK |
655 | */ |
656 | sbi = nilfs->ns_current; | |
657 | if (rw_mount) { | |
658 | if (sbi && !(sbi->s_super->s_flags & MS_RDONLY)) | |
659 | goto found; /* read/write mount */ | |
660 | else | |
661 | goto out; | |
662 | } else if (cno == 0) { | |
663 | if (sbi && (sbi->s_super->s_flags & MS_RDONLY)) | |
664 | goto found; /* read-only mount */ | |
665 | else | |
666 | goto out; | |
667 | } | |
668 | ||
669 | list_for_each_entry(sbi, &nilfs->ns_supers, s_list) { | |
670 | if (nilfs_test_opt(sbi, SNAPSHOT) && | |
671 | sbi->s_snapshot_cno == cno) | |
672 | goto found; /* snapshot mount */ | |
673 | } | |
674 | out: | |
e59399d0 | 675 | up_read(&nilfs->ns_super_sem); |
6dd47406 RK |
676 | return NULL; |
677 | ||
678 | found: | |
679 | atomic_inc(&sbi->s_count); | |
e59399d0 | 680 | up_read(&nilfs->ns_super_sem); |
6dd47406 RK |
681 | return sbi; |
682 | } | |
683 | ||
8a9d2191 RK |
684 | int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno, |
685 | int snapshot_mount) | |
686 | { | |
687 | struct nilfs_sb_info *sbi; | |
688 | int ret = 0; | |
689 | ||
e59399d0 | 690 | down_read(&nilfs->ns_super_sem); |
8a9d2191 RK |
691 | if (cno == 0 || cno > nilfs->ns_cno) |
692 | goto out_unlock; | |
693 | ||
694 | list_for_each_entry(sbi, &nilfs->ns_supers, s_list) { | |
695 | if (sbi->s_snapshot_cno == cno && | |
696 | (!snapshot_mount || nilfs_test_opt(sbi, SNAPSHOT))) { | |
697 | /* exclude read-only mounts */ | |
698 | ret++; | |
699 | break; | |
700 | } | |
701 | } | |
702 | /* for protecting recent checkpoints */ | |
703 | if (cno >= nilfs_last_cno(nilfs)) | |
704 | ret++; | |
705 | ||
706 | out_unlock: | |
e59399d0 | 707 | up_read(&nilfs->ns_super_sem); |
8a9d2191 RK |
708 | return ret; |
709 | } |