2 * the_nilfs.c - the_nilfs shared structure.
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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.
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.
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
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
24 #include <linux/buffer_head.h>
25 #include <linux/slab.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.h>
37 void nilfs_set_last_segment(struct the_nilfs *nilfs,
38 sector_t start_blocknr, u64 seq, __u64 cno)
40 spin_lock(&nilfs->ns_last_segment_lock);
41 nilfs->ns_last_pseg = start_blocknr;
42 nilfs->ns_last_seq = seq;
43 nilfs->ns_last_cno = cno;
44 spin_unlock(&nilfs->ns_last_segment_lock);
48 * alloc_nilfs - allocate the_nilfs structure
49 * @bdev: block device to which the_nilfs is related
51 * alloc_nilfs() allocates memory for the_nilfs and
52 * initializes its reference count and locks.
54 * Return Value: On success, pointer to the_nilfs is returned.
55 * On error, NULL is returned.
57 struct the_nilfs *alloc_nilfs(struct block_device *bdev)
59 struct the_nilfs *nilfs;
61 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
65 nilfs->ns_bdev = bdev;
66 atomic_set(&nilfs->ns_count, 1);
67 atomic_set(&nilfs->ns_writer_refcount, -1);
68 atomic_set(&nilfs->ns_ndirtyblks, 0);
69 init_rwsem(&nilfs->ns_sem);
70 mutex_init(&nilfs->ns_writer_mutex);
71 INIT_LIST_HEAD(&nilfs->ns_supers);
72 spin_lock_init(&nilfs->ns_last_segment_lock);
73 nilfs->ns_gc_inodes_h = NULL;
74 INIT_LIST_HEAD(&nilfs->ns_used_segments);
75 init_rwsem(&nilfs->ns_segctor_sem);
81 * put_nilfs - release a reference to the_nilfs
82 * @nilfs: the_nilfs structure to be released
84 * put_nilfs() decrements a reference counter of the_nilfs.
85 * If the reference count reaches zero, the_nilfs is freed.
87 void put_nilfs(struct the_nilfs *nilfs)
89 if (!atomic_dec_and_test(&nilfs->ns_count))
92 * Increment of ns_count never occur below because the caller
93 * of get_nilfs() holds at least one reference to the_nilfs.
94 * Thus its exclusion control is not required here.
97 if (nilfs_loaded(nilfs)) {
98 nilfs_dispose_used_segments(nilfs);
99 nilfs_mdt_clear(nilfs->ns_sufile);
100 nilfs_mdt_destroy(nilfs->ns_sufile);
101 nilfs_mdt_clear(nilfs->ns_cpfile);
102 nilfs_mdt_destroy(nilfs->ns_cpfile);
103 nilfs_mdt_clear(nilfs->ns_dat);
104 nilfs_mdt_destroy(nilfs->ns_dat);
105 /* XXX: how and when to clear nilfs->ns_gc_dat? */
106 nilfs_mdt_destroy(nilfs->ns_gc_dat);
108 if (nilfs_init(nilfs)) {
109 nilfs_destroy_gccache(nilfs);
110 brelse(nilfs->ns_sbh);
115 static int nilfs_load_super_root(struct the_nilfs *nilfs,
116 struct nilfs_sb_info *sbi, sector_t sr_block)
118 struct buffer_head *bh_sr;
119 struct nilfs_super_root *raw_sr;
120 unsigned dat_entry_size, segment_usage_size, checkpoint_size;
124 err = nilfs_read_super_root_block(sbi->s_super, sr_block, &bh_sr, 1);
128 down_read(&nilfs->ns_sem);
129 dat_entry_size = le16_to_cpu(nilfs->ns_sbp->s_dat_entry_size);
130 checkpoint_size = le16_to_cpu(nilfs->ns_sbp->s_checkpoint_size);
131 segment_usage_size = le16_to_cpu(nilfs->ns_sbp->s_segment_usage_size);
132 up_read(&nilfs->ns_sem);
134 inode_size = nilfs->ns_inode_size;
137 nilfs->ns_dat = nilfs_mdt_new(
138 nilfs, NULL, NILFS_DAT_INO, NILFS_DAT_GFP);
139 if (unlikely(!nilfs->ns_dat))
142 nilfs->ns_gc_dat = nilfs_mdt_new(
143 nilfs, NULL, NILFS_DAT_INO, NILFS_DAT_GFP);
144 if (unlikely(!nilfs->ns_gc_dat))
147 nilfs->ns_cpfile = nilfs_mdt_new(
148 nilfs, NULL, NILFS_CPFILE_INO, NILFS_CPFILE_GFP);
149 if (unlikely(!nilfs->ns_cpfile))
152 nilfs->ns_sufile = nilfs_mdt_new(
153 nilfs, NULL, NILFS_SUFILE_INO, NILFS_SUFILE_GFP);
154 if (unlikely(!nilfs->ns_sufile))
157 err = nilfs_palloc_init_blockgroup(nilfs->ns_dat, dat_entry_size);
161 err = nilfs_palloc_init_blockgroup(nilfs->ns_gc_dat, dat_entry_size);
165 nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat);
166 nilfs_mdt_set_entry_size(nilfs->ns_cpfile, checkpoint_size,
167 sizeof(struct nilfs_cpfile_header));
168 nilfs_mdt_set_entry_size(nilfs->ns_sufile, segment_usage_size,
169 sizeof(struct nilfs_sufile_header));
171 err = nilfs_mdt_read_inode_direct(
172 nilfs->ns_dat, bh_sr, NILFS_SR_DAT_OFFSET(inode_size));
176 err = nilfs_mdt_read_inode_direct(
177 nilfs->ns_cpfile, bh_sr, NILFS_SR_CPFILE_OFFSET(inode_size));
181 err = nilfs_mdt_read_inode_direct(
182 nilfs->ns_sufile, bh_sr, NILFS_SR_SUFILE_OFFSET(inode_size));
186 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
187 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
194 nilfs_mdt_destroy(nilfs->ns_sufile);
197 nilfs_mdt_destroy(nilfs->ns_cpfile);
200 nilfs_mdt_destroy(nilfs->ns_gc_dat);
203 nilfs_mdt_destroy(nilfs->ns_dat);
207 static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
209 memset(ri, 0, sizeof(*ri));
210 INIT_LIST_HEAD(&ri->ri_used_segments);
213 static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
215 nilfs_dispose_segment_list(&ri->ri_used_segments);
219 * load_nilfs - load and recover the nilfs
220 * @nilfs: the_nilfs structure to be released
221 * @sbi: nilfs_sb_info used to recover past segment
223 * load_nilfs() searches and load the latest super root,
224 * attaches the last segment, and does recovery if needed.
225 * The caller must call this exclusively for simultaneous mounts.
227 int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
229 struct nilfs_recovery_info ri;
230 unsigned int s_flags = sbi->s_super->s_flags;
231 int really_read_only = bdev_read_only(nilfs->ns_bdev);
235 nilfs_init_recovery_info(&ri);
237 down_write(&nilfs->ns_sem);
238 valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
239 up_write(&nilfs->ns_sem);
241 if (!valid_fs && (s_flags & MS_RDONLY)) {
242 printk(KERN_INFO "NILFS: INFO: recovery "
243 "required for readonly filesystem.\n");
244 if (really_read_only) {
245 printk(KERN_ERR "NILFS: write access "
246 "unavailable, cannot proceed.\n");
250 printk(KERN_INFO "NILFS: write access will "
251 "be enabled during recovery.\n");
252 sbi->s_super->s_flags &= ~MS_RDONLY;
255 err = nilfs_search_super_root(nilfs, sbi, &ri);
257 printk(KERN_ERR "NILFS: error searching super root.\n");
261 err = nilfs_load_super_root(nilfs, sbi, ri.ri_super_root);
263 printk(KERN_ERR "NILFS: error loading super root.\n");
268 err = nilfs_recover_logical_segments(nilfs, sbi, &ri);
270 nilfs_mdt_destroy(nilfs->ns_cpfile);
271 nilfs_mdt_destroy(nilfs->ns_sufile);
272 nilfs_mdt_destroy(nilfs->ns_dat);
275 if (ri.ri_need_recovery == NILFS_RECOVERY_SR_UPDATED) {
276 down_write(&nilfs->ns_sem);
277 nilfs_update_last_segment(sbi, 0);
278 up_write(&nilfs->ns_sem);
282 set_nilfs_loaded(nilfs);
285 nilfs_clear_recovery_info(&ri);
286 sbi->s_super->s_flags = s_flags;
290 static unsigned long long nilfs_max_size(unsigned int blkbits)
292 unsigned int max_bits;
293 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
295 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
297 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
302 nilfs_store_disk_layout(struct the_nilfs *nilfs, struct super_block *sb,
303 struct nilfs_super_block *sbp)
305 if (le32_to_cpu(sbp->s_rev_level) != NILFS_CURRENT_REV) {
306 printk(KERN_ERR "NILFS: revision mismatch "
307 "(superblock rev.=%d.%d, current rev.=%d.%d). "
308 "Please check the version of mkfs.nilfs.\n",
309 le32_to_cpu(sbp->s_rev_level),
310 le16_to_cpu(sbp->s_minor_rev_level),
311 NILFS_CURRENT_REV, NILFS_MINOR_REV);
314 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
315 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
317 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
318 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
319 printk(KERN_ERR "NILFS: too short segment. \n");
323 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
324 nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments);
325 nilfs->ns_r_segments_percentage =
326 le32_to_cpu(sbp->s_r_segments_percentage);
328 max_t(unsigned long, NILFS_MIN_NRSVSEGS,
329 DIV_ROUND_UP(nilfs->ns_nsegments *
330 nilfs->ns_r_segments_percentage, 100));
331 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
336 * init_nilfs - initialize a NILFS instance.
337 * @nilfs: the_nilfs structure
338 * @sbi: nilfs_sb_info
340 * @data: mount options
342 * init_nilfs() performs common initialization per block device (e.g.
343 * reading the super block, getting disk layout information, initializing
344 * shared fields in the_nilfs). It takes on some portion of the jobs
345 * typically done by a fill_super() routine. This division arises from
346 * the nature that multiple NILFS instances may be simultaneously
347 * mounted on a device.
348 * For multiple mounts on the same device, only the first mount
349 * invokes these tasks.
351 * Return Value: On success, 0 is returned. On error, a negative error
354 int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data)
356 struct super_block *sb = sbi->s_super;
357 struct buffer_head *sbh;
358 struct nilfs_super_block *sbp;
359 struct backing_dev_info *bdi;
363 down_write(&nilfs->ns_sem);
364 if (nilfs_init(nilfs)) {
365 /* Load values from existing the_nilfs */
367 err = nilfs_store_magic_and_option(sb, sbp, data);
371 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
372 if (sb->s_blocksize != blocksize &&
373 !sb_set_blocksize(sb, blocksize)) {
374 printk(KERN_ERR "NILFS: blocksize %d unfit to device\n",
378 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
382 sbp = nilfs_load_super_block(sb, &sbh);
387 err = nilfs_store_magic_and_option(sb, sbp, data);
391 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
392 if (sb->s_blocksize != blocksize) {
393 sbp = nilfs_reload_super_block(sb, &sbh, blocksize);
397 /* not failed_sbh; sbh is released automatically
398 when reloading fails. */
401 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
403 err = nilfs_store_disk_layout(nilfs, sb, sbp);
407 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
409 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
413 bdi = nilfs->ns_bdev->bd_inode_backing_dev_info;
415 bdi = nilfs->ns_bdev->bd_inode->i_mapping->backing_dev_info;
416 nilfs->ns_bdi = bdi ? : &default_backing_dev_info;
418 /* Finding last segment */
419 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
420 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
421 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
423 nilfs->ns_seg_seq = nilfs->ns_last_seq;
425 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
426 nilfs->ns_cno = nilfs->ns_last_cno + 1;
427 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
428 printk(KERN_ERR "NILFS invalid last segment number.\n");
433 nilfs->ns_free_segments_count =
434 nilfs->ns_nsegments - (nilfs->ns_segnum + 1);
436 /* Initialize gcinode cache */
437 err = nilfs_init_gccache(nilfs);
441 set_nilfs_init(nilfs);
444 up_write(&nilfs->ns_sem);
452 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
454 struct inode *dat = nilfs_dat_inode(nilfs);
455 unsigned long ncleansegs;
458 down_read(&NILFS_MDT(dat)->mi_sem); /* XXX */
459 err = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile, &ncleansegs);
460 up_read(&NILFS_MDT(dat)->mi_sem); /* XXX */
462 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
466 void nilfs_dispose_used_segments(struct the_nilfs *nilfs)
468 struct nilfs_segment_entry *ent, *n;
470 /* nilfs->sem must be locked by the caller. */
471 if (!nilfs_loaded(nilfs))
474 list_for_each_entry_safe(ent, n, &nilfs->ns_used_segments, list) {
475 list_del_init(&ent->list);
476 nilfs_segment_usage_clear_volatile_active(ent->raw_su);
477 nilfs_close_segment_entry(ent, nilfs->ns_sufile);
478 nilfs_free_segment_entry(ent);
482 int nilfs_near_disk_full(struct the_nilfs *nilfs)
484 struct inode *sufile = nilfs->ns_sufile;
485 unsigned long ncleansegs, nincsegs;
488 ret = nilfs_sufile_get_ncleansegs(sufile, &ncleansegs);
490 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
491 nilfs->ns_blocks_per_segment + 1;
492 if (ncleansegs <= nilfs->ns_nrsvsegs + nincsegs)
498 int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno,
501 struct nilfs_sb_info *sbi;
504 down_read(&nilfs->ns_sem);
505 if (cno == 0 || cno > nilfs->ns_cno)
508 list_for_each_entry(sbi, &nilfs->ns_supers, s_list) {
509 if (sbi->s_snapshot_cno == cno &&
510 (!snapshot_mount || nilfs_test_opt(sbi, SNAPSHOT))) {
511 /* exclude read-only mounts */
516 /* for protecting recent checkpoints */
517 if (cno >= nilfs_last_cno(nilfs))
521 up_read(&nilfs->ns_sem);