blob: 8b8889825716a9df7b7f71cff2102d89ee547eec [file] [log] [blame]
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -07001/*
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>
Ryusuke Konishie339ad32009-04-06 19:01:59 -070028#include <linux/crc32.h>
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -070029#include "nilfs.h"
30#include "segment.h"
31#include "alloc.h"
32#include "cpfile.h"
33#include "sufile.h"
34#include "dat.h"
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -070035#include "segbuf.h"
36
Ryusuke Konishi33c8e572009-06-08 01:39:29 +090037
38static LIST_HEAD(nilfs_objects);
39static DEFINE_SPINLOCK(nilfs_lock);
40
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -070041void 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 */
Ryusuke Konishi33c8e572009-06-08 01:39:29 +090061static struct the_nilfs *alloc_nilfs(struct block_device *bdev)
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -070062{
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_writer_refcount, -1);
72 atomic_set(&nilfs->ns_ndirtyblks, 0);
73 init_rwsem(&nilfs->ns_sem);
Ryusuke Konishie59399d2009-06-08 01:39:32 +090074 init_rwsem(&nilfs->ns_super_sem);
Ryusuke Konishiaa7dfb82009-06-08 01:39:33 +090075 mutex_init(&nilfs->ns_mount_mutex);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -070076 mutex_init(&nilfs->ns_writer_mutex);
Ryusuke Konishi33c8e572009-06-08 01:39:29 +090077 INIT_LIST_HEAD(&nilfs->ns_list);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -070078 INIT_LIST_HEAD(&nilfs->ns_supers);
79 spin_lock_init(&nilfs->ns_last_segment_lock);
80 nilfs->ns_gc_inodes_h = NULL;
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -070081 init_rwsem(&nilfs->ns_segctor_sem);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -070082
83 return nilfs;
84}
85
86/**
Ryusuke Konishi33c8e572009-06-08 01:39:29 +090087 * find_or_create_nilfs - find or create nilfs object
88 * @bdev: block device to which the_nilfs is related
89 *
90 * find_nilfs() looks up an existent nilfs object created on the
91 * device and gets the reference count of the object. If no nilfs object
92 * is found on the device, a new nilfs object is allocated.
93 *
94 * Return Value: On success, pointer to the nilfs object is returned.
95 * On error, NULL is returned.
96 */
97struct the_nilfs *find_or_create_nilfs(struct block_device *bdev)
98{
99 struct the_nilfs *nilfs, *new = NULL;
100
101 retry:
102 spin_lock(&nilfs_lock);
103 list_for_each_entry(nilfs, &nilfs_objects, ns_list) {
104 if (nilfs->ns_bdev == bdev) {
105 get_nilfs(nilfs);
106 spin_unlock(&nilfs_lock);
107 if (new)
108 put_nilfs(new);
109 return nilfs; /* existing object */
110 }
111 }
112 if (new) {
113 list_add_tail(&new->ns_list, &nilfs_objects);
114 spin_unlock(&nilfs_lock);
115 return new; /* new object */
116 }
117 spin_unlock(&nilfs_lock);
118
119 new = alloc_nilfs(bdev);
120 if (new)
121 goto retry;
122 return NULL; /* insufficient memory */
123}
124
125/**
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700126 * put_nilfs - release a reference to the_nilfs
127 * @nilfs: the_nilfs structure to be released
128 *
129 * put_nilfs() decrements a reference counter of the_nilfs.
130 * If the reference count reaches zero, the_nilfs is freed.
131 */
132void put_nilfs(struct the_nilfs *nilfs)
133{
Ryusuke Konishi33c8e572009-06-08 01:39:29 +0900134 spin_lock(&nilfs_lock);
135 if (!atomic_dec_and_test(&nilfs->ns_count)) {
136 spin_unlock(&nilfs_lock);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700137 return;
Ryusuke Konishi33c8e572009-06-08 01:39:29 +0900138 }
139 list_del_init(&nilfs->ns_list);
140 spin_unlock(&nilfs_lock);
141
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700142 /*
Ryusuke Konishi33c8e572009-06-08 01:39:29 +0900143 * Increment of ns_count never occurs below because the caller
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700144 * of get_nilfs() holds at least one reference to the_nilfs.
145 * Thus its exclusion control is not required here.
146 */
Ryusuke Konishi33c8e572009-06-08 01:39:29 +0900147
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700148 might_sleep();
149 if (nilfs_loaded(nilfs)) {
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700150 nilfs_mdt_clear(nilfs->ns_sufile);
151 nilfs_mdt_destroy(nilfs->ns_sufile);
152 nilfs_mdt_clear(nilfs->ns_cpfile);
153 nilfs_mdt_destroy(nilfs->ns_cpfile);
154 nilfs_mdt_clear(nilfs->ns_dat);
155 nilfs_mdt_destroy(nilfs->ns_dat);
156 /* XXX: how and when to clear nilfs->ns_gc_dat? */
157 nilfs_mdt_destroy(nilfs->ns_gc_dat);
158 }
159 if (nilfs_init(nilfs)) {
160 nilfs_destroy_gccache(nilfs);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700161 brelse(nilfs->ns_sbh[0]);
162 brelse(nilfs->ns_sbh[1]);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700163 }
164 kfree(nilfs);
165}
166
167static int nilfs_load_super_root(struct the_nilfs *nilfs,
168 struct nilfs_sb_info *sbi, sector_t sr_block)
169{
Ryusuke Konishic2698e52009-03-27 02:53:12 +0900170 static struct lock_class_key dat_lock_key;
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700171 struct buffer_head *bh_sr;
172 struct nilfs_super_root *raw_sr;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700173 struct nilfs_super_block **sbp = nilfs->ns_sbp;
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700174 unsigned dat_entry_size, segment_usage_size, checkpoint_size;
175 unsigned inode_size;
176 int err;
177
178 err = nilfs_read_super_root_block(sbi->s_super, sr_block, &bh_sr, 1);
179 if (unlikely(err))
180 return err;
181
182 down_read(&nilfs->ns_sem);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700183 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
184 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
185 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700186 up_read(&nilfs->ns_sem);
187
188 inode_size = nilfs->ns_inode_size;
189
190 err = -ENOMEM;
191 nilfs->ns_dat = nilfs_mdt_new(
192 nilfs, NULL, NILFS_DAT_INO, NILFS_DAT_GFP);
193 if (unlikely(!nilfs->ns_dat))
194 goto failed;
195
196 nilfs->ns_gc_dat = nilfs_mdt_new(
197 nilfs, NULL, NILFS_DAT_INO, NILFS_DAT_GFP);
198 if (unlikely(!nilfs->ns_gc_dat))
199 goto failed_dat;
200
201 nilfs->ns_cpfile = nilfs_mdt_new(
202 nilfs, NULL, NILFS_CPFILE_INO, NILFS_CPFILE_GFP);
203 if (unlikely(!nilfs->ns_cpfile))
204 goto failed_gc_dat;
205
206 nilfs->ns_sufile = nilfs_mdt_new(
207 nilfs, NULL, NILFS_SUFILE_INO, NILFS_SUFILE_GFP);
208 if (unlikely(!nilfs->ns_sufile))
209 goto failed_cpfile;
210
211 err = nilfs_palloc_init_blockgroup(nilfs->ns_dat, dat_entry_size);
212 if (unlikely(err))
213 goto failed_sufile;
214
215 err = nilfs_palloc_init_blockgroup(nilfs->ns_gc_dat, dat_entry_size);
216 if (unlikely(err))
217 goto failed_sufile;
218
Ryusuke Konishic2698e52009-03-27 02:53:12 +0900219 lockdep_set_class(&NILFS_MDT(nilfs->ns_dat)->mi_sem, &dat_lock_key);
220 lockdep_set_class(&NILFS_MDT(nilfs->ns_gc_dat)->mi_sem, &dat_lock_key);
221
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700222 nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat);
223 nilfs_mdt_set_entry_size(nilfs->ns_cpfile, checkpoint_size,
224 sizeof(struct nilfs_cpfile_header));
225 nilfs_mdt_set_entry_size(nilfs->ns_sufile, segment_usage_size,
226 sizeof(struct nilfs_sufile_header));
227
228 err = nilfs_mdt_read_inode_direct(
229 nilfs->ns_dat, bh_sr, NILFS_SR_DAT_OFFSET(inode_size));
230 if (unlikely(err))
231 goto failed_sufile;
232
233 err = nilfs_mdt_read_inode_direct(
234 nilfs->ns_cpfile, bh_sr, NILFS_SR_CPFILE_OFFSET(inode_size));
235 if (unlikely(err))
236 goto failed_sufile;
237
238 err = nilfs_mdt_read_inode_direct(
239 nilfs->ns_sufile, bh_sr, NILFS_SR_SUFILE_OFFSET(inode_size));
240 if (unlikely(err))
241 goto failed_sufile;
242
243 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
244 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
245
246 failed:
247 brelse(bh_sr);
248 return err;
249
250 failed_sufile:
251 nilfs_mdt_destroy(nilfs->ns_sufile);
252
253 failed_cpfile:
254 nilfs_mdt_destroy(nilfs->ns_cpfile);
255
256 failed_gc_dat:
257 nilfs_mdt_destroy(nilfs->ns_gc_dat);
258
259 failed_dat:
260 nilfs_mdt_destroy(nilfs->ns_dat);
261 goto failed;
262}
263
264static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
265{
266 memset(ri, 0, sizeof(*ri));
267 INIT_LIST_HEAD(&ri->ri_used_segments);
268}
269
270static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
271{
272 nilfs_dispose_segment_list(&ri->ri_used_segments);
273}
274
275/**
276 * load_nilfs - load and recover the nilfs
277 * @nilfs: the_nilfs structure to be released
278 * @sbi: nilfs_sb_info used to recover past segment
279 *
280 * load_nilfs() searches and load the latest super root,
281 * attaches the last segment, and does recovery if needed.
282 * The caller must call this exclusively for simultaneous mounts.
283 */
284int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
285{
286 struct nilfs_recovery_info ri;
287 unsigned int s_flags = sbi->s_super->s_flags;
288 int really_read_only = bdev_read_only(nilfs->ns_bdev);
289 unsigned valid_fs;
290 int err = 0;
291
292 nilfs_init_recovery_info(&ri);
293
294 down_write(&nilfs->ns_sem);
295 valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
296 up_write(&nilfs->ns_sem);
297
298 if (!valid_fs && (s_flags & MS_RDONLY)) {
299 printk(KERN_INFO "NILFS: INFO: recovery "
300 "required for readonly filesystem.\n");
301 if (really_read_only) {
302 printk(KERN_ERR "NILFS: write access "
303 "unavailable, cannot proceed.\n");
304 err = -EROFS;
305 goto failed;
306 }
307 printk(KERN_INFO "NILFS: write access will "
308 "be enabled during recovery.\n");
309 sbi->s_super->s_flags &= ~MS_RDONLY;
310 }
311
312 err = nilfs_search_super_root(nilfs, sbi, &ri);
313 if (unlikely(err)) {
314 printk(KERN_ERR "NILFS: error searching super root.\n");
315 goto failed;
316 }
317
318 err = nilfs_load_super_root(nilfs, sbi, ri.ri_super_root);
319 if (unlikely(err)) {
320 printk(KERN_ERR "NILFS: error loading super root.\n");
321 goto failed;
322 }
323
324 if (!valid_fs) {
325 err = nilfs_recover_logical_segments(nilfs, sbi, &ri);
326 if (unlikely(err)) {
327 nilfs_mdt_destroy(nilfs->ns_cpfile);
328 nilfs_mdt_destroy(nilfs->ns_sufile);
329 nilfs_mdt_destroy(nilfs->ns_dat);
330 goto failed;
331 }
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700332 if (ri.ri_need_recovery == NILFS_RECOVERY_SR_UPDATED)
333 sbi->s_super->s_dirt = 1;
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700334 }
335
336 set_nilfs_loaded(nilfs);
337
338 failed:
339 nilfs_clear_recovery_info(&ri);
340 sbi->s_super->s_flags = s_flags;
341 return err;
342}
343
344static unsigned long long nilfs_max_size(unsigned int blkbits)
345{
346 unsigned int max_bits;
347 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
348
349 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
350 if (max_bits < 64)
351 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
352 return res;
353}
354
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700355static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
356 struct nilfs_super_block *sbp)
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700357{
358 if (le32_to_cpu(sbp->s_rev_level) != NILFS_CURRENT_REV) {
359 printk(KERN_ERR "NILFS: revision mismatch "
360 "(superblock rev.=%d.%d, current rev.=%d.%d). "
361 "Please check the version of mkfs.nilfs.\n",
362 le32_to_cpu(sbp->s_rev_level),
363 le16_to_cpu(sbp->s_minor_rev_level),
364 NILFS_CURRENT_REV, NILFS_MINOR_REV);
365 return -EINVAL;
366 }
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700367 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
368 if (nilfs->ns_sbsize > BLOCK_SIZE)
369 return -EINVAL;
370
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700371 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
372 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
373
374 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
375 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
376 printk(KERN_ERR "NILFS: too short segment. \n");
377 return -EINVAL;
378 }
379
380 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
381 nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments);
382 nilfs->ns_r_segments_percentage =
383 le32_to_cpu(sbp->s_r_segments_percentage);
384 nilfs->ns_nrsvsegs =
385 max_t(unsigned long, NILFS_MIN_NRSVSEGS,
386 DIV_ROUND_UP(nilfs->ns_nsegments *
387 nilfs->ns_r_segments_percentage, 100));
388 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
389 return 0;
390}
391
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700392static int nilfs_valid_sb(struct nilfs_super_block *sbp)
393{
394 static unsigned char sum[4];
395 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
396 size_t bytes;
397 u32 crc;
398
399 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
400 return 0;
401 bytes = le16_to_cpu(sbp->s_bytes);
402 if (bytes > BLOCK_SIZE)
403 return 0;
404 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
405 sumoff);
406 crc = crc32_le(crc, sum, 4);
407 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
408 bytes - sumoff - 4);
409 return crc == le32_to_cpu(sbp->s_sum);
410}
411
412static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
413{
414 return offset < ((le64_to_cpu(sbp->s_nsegments) *
415 le32_to_cpu(sbp->s_blocks_per_segment)) <<
416 (le32_to_cpu(sbp->s_log_block_size) + 10));
417}
418
419static void nilfs_release_super_block(struct the_nilfs *nilfs)
420{
421 int i;
422
423 for (i = 0; i < 2; i++) {
424 if (nilfs->ns_sbp[i]) {
425 brelse(nilfs->ns_sbh[i]);
426 nilfs->ns_sbh[i] = NULL;
427 nilfs->ns_sbp[i] = NULL;
428 }
429 }
430}
431
432void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
433{
434 brelse(nilfs->ns_sbh[0]);
435 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
436 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
437 nilfs->ns_sbh[1] = NULL;
438 nilfs->ns_sbp[1] = NULL;
439}
440
441void nilfs_swap_super_block(struct the_nilfs *nilfs)
442{
443 struct buffer_head *tsbh = nilfs->ns_sbh[0];
444 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
445
446 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
447 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
448 nilfs->ns_sbh[1] = tsbh;
449 nilfs->ns_sbp[1] = tsbp;
450}
451
452static int nilfs_load_super_block(struct the_nilfs *nilfs,
453 struct super_block *sb, int blocksize,
454 struct nilfs_super_block **sbpp)
455{
456 struct nilfs_super_block **sbp = nilfs->ns_sbp;
457 struct buffer_head **sbh = nilfs->ns_sbh;
458 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
459 int valid[2], swp = 0;
460
461 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
462 &sbh[0]);
463 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
464
465 if (!sbp[0]) {
466 if (!sbp[1]) {
467 printk(KERN_ERR "NILFS: unable to read superblock\n");
468 return -EIO;
469 }
470 printk(KERN_WARNING
471 "NILFS warning: unable to read primary superblock\n");
472 } else if (!sbp[1])
473 printk(KERN_WARNING
474 "NILFS warning: unable to read secondary superblock\n");
475
476 valid[0] = nilfs_valid_sb(sbp[0]);
477 valid[1] = nilfs_valid_sb(sbp[1]);
478 swp = valid[1] &&
479 (!valid[0] ||
480 le64_to_cpu(sbp[1]->s_wtime) > le64_to_cpu(sbp[0]->s_wtime));
481
482 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
483 brelse(sbh[1]);
484 sbh[1] = NULL;
485 sbp[1] = NULL;
486 swp = 0;
487 }
488 if (!valid[swp]) {
489 nilfs_release_super_block(nilfs);
490 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n",
491 sb->s_id);
492 return -EINVAL;
493 }
494
495 if (swp) {
496 printk(KERN_WARNING "NILFS warning: broken superblock. "
497 "using spare superblock.\n");
498 nilfs_swap_super_block(nilfs);
499 }
500
501 nilfs->ns_sbwtime[0] = le64_to_cpu(sbp[0]->s_wtime);
502 nilfs->ns_sbwtime[1] = valid[!swp] ? le64_to_cpu(sbp[1]->s_wtime) : 0;
503 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
504 *sbpp = sbp[0];
505 return 0;
506}
507
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700508/**
509 * init_nilfs - initialize a NILFS instance.
510 * @nilfs: the_nilfs structure
511 * @sbi: nilfs_sb_info
512 * @sb: super block
513 * @data: mount options
514 *
515 * init_nilfs() performs common initialization per block device (e.g.
516 * reading the super block, getting disk layout information, initializing
517 * shared fields in the_nilfs). It takes on some portion of the jobs
518 * typically done by a fill_super() routine. This division arises from
519 * the nature that multiple NILFS instances may be simultaneously
520 * mounted on a device.
521 * For multiple mounts on the same device, only the first mount
522 * invokes these tasks.
523 *
524 * Return Value: On success, 0 is returned. On error, a negative error
525 * code is returned.
526 */
527int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data)
528{
529 struct super_block *sb = sbi->s_super;
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700530 struct nilfs_super_block *sbp;
531 struct backing_dev_info *bdi;
532 int blocksize;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700533 int err;
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700534
535 down_write(&nilfs->ns_sem);
536 if (nilfs_init(nilfs)) {
537 /* Load values from existing the_nilfs */
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700538 sbp = nilfs->ns_sbp[0];
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700539 err = nilfs_store_magic_and_option(sb, sbp, data);
540 if (err)
541 goto out;
542
543 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
544 if (sb->s_blocksize != blocksize &&
545 !sb_set_blocksize(sb, blocksize)) {
546 printk(KERN_ERR "NILFS: blocksize %d unfit to device\n",
547 blocksize);
548 err = -EINVAL;
549 }
550 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
551 goto out;
552 }
553
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700554 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
555 if (!blocksize) {
556 printk(KERN_ERR "NILFS: unable to set blocksize\n");
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700557 err = -EINVAL;
558 goto out;
559 }
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700560 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
561 if (err)
562 goto out;
563
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700564 err = nilfs_store_magic_and_option(sb, sbp, data);
565 if (err)
566 goto failed_sbh;
567
568 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
569 if (sb->s_blocksize != blocksize) {
Martin K. Petersene1defc42009-05-22 17:17:49 -0400570 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700571
572 if (blocksize < hw_blocksize) {
573 printk(KERN_ERR
574 "NILFS: blocksize %d too small for device "
575 "(sector-size = %d).\n",
576 blocksize, hw_blocksize);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700577 err = -EINVAL;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700578 goto failed_sbh;
579 }
580 nilfs_release_super_block(nilfs);
581 sb_set_blocksize(sb, blocksize);
582
583 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
584 if (err)
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700585 goto out;
586 /* not failed_sbh; sbh is released automatically
587 when reloading fails. */
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700588 }
589 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
590
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700591 err = nilfs_store_disk_layout(nilfs, sbp);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700592 if (err)
593 goto failed_sbh;
594
595 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
596
597 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700598
599 bdi = nilfs->ns_bdev->bd_inode_backing_dev_info;
600 if (!bdi)
601 bdi = nilfs->ns_bdev->bd_inode->i_mapping->backing_dev_info;
602 nilfs->ns_bdi = bdi ? : &default_backing_dev_info;
603
604 /* Finding last segment */
605 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
606 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
607 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
608
609 nilfs->ns_seg_seq = nilfs->ns_last_seq;
610 nilfs->ns_segnum =
611 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
612 nilfs->ns_cno = nilfs->ns_last_cno + 1;
613 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
614 printk(KERN_ERR "NILFS invalid last segment number.\n");
615 err = -EINVAL;
616 goto failed_sbh;
617 }
618 /* Dummy values */
619 nilfs->ns_free_segments_count =
620 nilfs->ns_nsegments - (nilfs->ns_segnum + 1);
621
622 /* Initialize gcinode cache */
623 err = nilfs_init_gccache(nilfs);
624 if (err)
625 goto failed_sbh;
626
627 set_nilfs_init(nilfs);
628 err = 0;
629 out:
630 up_write(&nilfs->ns_sem);
631 return err;
632
633 failed_sbh:
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700634 nilfs_release_super_block(nilfs);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700635 goto out;
636}
637
638int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
639{
640 struct inode *dat = nilfs_dat_inode(nilfs);
641 unsigned long ncleansegs;
642 int err;
643
644 down_read(&NILFS_MDT(dat)->mi_sem); /* XXX */
645 err = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile, &ncleansegs);
646 up_read(&NILFS_MDT(dat)->mi_sem); /* XXX */
647 if (likely(!err))
648 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
649 return err;
650}
651
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700652int nilfs_near_disk_full(struct the_nilfs *nilfs)
653{
654 struct inode *sufile = nilfs->ns_sufile;
655 unsigned long ncleansegs, nincsegs;
656 int ret;
657
658 ret = nilfs_sufile_get_ncleansegs(sufile, &ncleansegs);
659 if (likely(!ret)) {
660 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
661 nilfs->ns_blocks_per_segment + 1;
662 if (ncleansegs <= nilfs->ns_nrsvsegs + nincsegs)
663 ret++;
664 }
665 return ret;
666}
667
Ryusuke Konishi6dd47402009-06-08 01:39:31 +0900668/**
669 * nilfs_find_sbinfo - find existing nilfs_sb_info structure
670 * @nilfs: nilfs object
671 * @rw_mount: mount type (non-zero value for read/write mount)
672 * @cno: checkpoint number (zero for read-only mount)
673 *
674 * nilfs_find_sbinfo() returns the nilfs_sb_info structure which
675 * @rw_mount and @cno (in case of snapshots) matched. If no instance
676 * was found, NULL is returned. Although the super block instance can
677 * be unmounted after this function returns, the nilfs_sb_info struct
678 * is kept on memory until nilfs_put_sbinfo() is called.
679 */
680struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *nilfs,
681 int rw_mount, __u64 cno)
682{
683 struct nilfs_sb_info *sbi;
684
Ryusuke Konishie59399d2009-06-08 01:39:32 +0900685 down_read(&nilfs->ns_super_sem);
Ryusuke Konishi6dd47402009-06-08 01:39:31 +0900686 /*
687 * The SNAPSHOT flag and sb->s_flags are supposed to be
Ryusuke Konishie59399d2009-06-08 01:39:32 +0900688 * protected with nilfs->ns_super_sem.
Ryusuke Konishi6dd47402009-06-08 01:39:31 +0900689 */
690 sbi = nilfs->ns_current;
691 if (rw_mount) {
692 if (sbi && !(sbi->s_super->s_flags & MS_RDONLY))
693 goto found; /* read/write mount */
694 else
695 goto out;
696 } else if (cno == 0) {
697 if (sbi && (sbi->s_super->s_flags & MS_RDONLY))
698 goto found; /* read-only mount */
699 else
700 goto out;
701 }
702
703 list_for_each_entry(sbi, &nilfs->ns_supers, s_list) {
704 if (nilfs_test_opt(sbi, SNAPSHOT) &&
705 sbi->s_snapshot_cno == cno)
706 goto found; /* snapshot mount */
707 }
708 out:
Ryusuke Konishie59399d2009-06-08 01:39:32 +0900709 up_read(&nilfs->ns_super_sem);
Ryusuke Konishi6dd47402009-06-08 01:39:31 +0900710 return NULL;
711
712 found:
713 atomic_inc(&sbi->s_count);
Ryusuke Konishie59399d2009-06-08 01:39:32 +0900714 up_read(&nilfs->ns_super_sem);
Ryusuke Konishi6dd47402009-06-08 01:39:31 +0900715 return sbi;
716}
717
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700718int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno,
719 int snapshot_mount)
720{
721 struct nilfs_sb_info *sbi;
722 int ret = 0;
723
Ryusuke Konishie59399d2009-06-08 01:39:32 +0900724 down_read(&nilfs->ns_super_sem);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700725 if (cno == 0 || cno > nilfs->ns_cno)
726 goto out_unlock;
727
728 list_for_each_entry(sbi, &nilfs->ns_supers, s_list) {
729 if (sbi->s_snapshot_cno == cno &&
730 (!snapshot_mount || nilfs_test_opt(sbi, SNAPSHOT))) {
731 /* exclude read-only mounts */
732 ret++;
733 break;
734 }
735 }
736 /* for protecting recent checkpoints */
737 if (cno >= nilfs_last_cno(nilfs))
738 ret++;
739
740 out_unlock:
Ryusuke Konishie59399d2009-06-08 01:39:32 +0900741 up_read(&nilfs->ns_super_sem);
Ryusuke Konishi8a9d2192009-04-06 19:01:35 -0700742 return ret;
743}