1 // SPDX-License-Identifier: GPL-2.0+
3 * NILFS module and super block management.
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
7 * Written by Ryusuke Konishi.
10 * linux/fs/ext2/super.c
12 * Copyright (C) 1992, 1993, 1994, 1995
13 * Remy Card (card@masi.ibp.fr)
14 * Laboratoire MASI - Institut Blaise Pascal
15 * Universite Pierre et Marie Curie (Paris VI)
19 * linux/fs/minix/inode.c
21 * Copyright (C) 1991, 1992 Linus Torvalds
23 * Big-endian to little-endian byte-swapping/bitmaps by
24 * David S. Miller (davem@caip.rutgers.edu), 1995
27 #include <linux/module.h>
28 #include <linux/string.h>
29 #include <linux/slab.h>
30 #include <linux/init.h>
31 #include <linux/blkdev.h>
32 #include <linux/parser.h>
33 #include <linux/crc32.h>
34 #include <linux/vfs.h>
35 #include <linux/writeback.h>
36 #include <linux/seq_file.h>
37 #include <linux/mount.h>
38 #include <linux/fs_context.h>
47 #include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
53 MODULE_AUTHOR("NTT Corp.");
54 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
56 MODULE_LICENSE("GPL");
58 static struct kmem_cache *nilfs_inode_cachep;
59 struct kmem_cache *nilfs_transaction_cachep;
60 struct kmem_cache *nilfs_segbuf_cachep;
61 struct kmem_cache *nilfs_btree_path_cache;
63 static int nilfs_setup_super(struct super_block *sb, int is_mount);
64 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
66 void __nilfs_msg(struct super_block *sb, const char *fmt, ...)
74 level = printk_get_level(fmt);
75 vaf.fmt = printk_skip_level(fmt);
79 printk("%c%cNILFS (%s): %pV\n",
80 KERN_SOH_ASCII, level, sb->s_id, &vaf);
82 printk("%c%cNILFS: %pV\n",
83 KERN_SOH_ASCII, level, &vaf);
88 static void nilfs_set_error(struct super_block *sb)
90 struct the_nilfs *nilfs = sb->s_fs_info;
91 struct nilfs_super_block **sbp;
93 down_write(&nilfs->ns_sem);
94 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
95 nilfs->ns_mount_state |= NILFS_ERROR_FS;
96 sbp = nilfs_prepare_super(sb, 0);
98 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
100 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
101 nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
104 up_write(&nilfs->ns_sem);
108 * __nilfs_error() - report failure condition on a filesystem
110 * __nilfs_error() sets an ERROR_FS flag on the superblock as well as
111 * reporting an error message. This function should be called when
112 * NILFS detects incoherences or defects of meta data on disk.
114 * This implements the body of nilfs_error() macro. Normally,
115 * nilfs_error() should be used. As for sustainable errors such as a
116 * single-shot I/O error, nilfs_err() should be used instead.
118 * Callers should not add a trailing newline since this will do it.
120 void __nilfs_error(struct super_block *sb, const char *function,
121 const char *fmt, ...)
123 struct the_nilfs *nilfs = sb->s_fs_info;
124 struct va_format vaf;
132 printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
133 sb->s_id, function, &vaf);
137 if (!sb_rdonly(sb)) {
140 if (nilfs_test_opt(nilfs, ERRORS_RO)) {
141 printk(KERN_CRIT "Remounting filesystem read-only\n");
142 sb->s_flags |= SB_RDONLY;
146 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
147 panic("NILFS (device %s): panic forced after error\n",
151 struct inode *nilfs_alloc_inode(struct super_block *sb)
153 struct nilfs_inode_info *ii;
155 ii = alloc_inode_sb(sb, nilfs_inode_cachep, GFP_NOFS);
161 ii->i_assoc_inode = NULL;
162 ii->i_bmap = &ii->i_bmap_data;
163 return &ii->vfs_inode;
166 static void nilfs_free_inode(struct inode *inode)
168 if (nilfs_is_metadata_file_inode(inode))
169 nilfs_mdt_destroy(inode);
171 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
174 static int nilfs_sync_super(struct super_block *sb, int flag)
176 struct the_nilfs *nilfs = sb->s_fs_info;
180 set_buffer_dirty(nilfs->ns_sbh[0]);
181 if (nilfs_test_opt(nilfs, BARRIER)) {
182 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
183 REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
185 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
189 nilfs_err(sb, "unable to write superblock: err=%d", err);
190 if (err == -EIO && nilfs->ns_sbh[1]) {
192 * sbp[0] points to newer log than sbp[1],
193 * so copy sbp[0] to sbp[1] to take over sbp[0].
195 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
197 nilfs_fall_back_super_block(nilfs);
201 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
203 nilfs->ns_sbwcount++;
206 * The latest segment becomes trailable from the position
207 * written in superblock.
209 clear_nilfs_discontinued(nilfs);
211 /* update GC protection for recent segments */
212 if (nilfs->ns_sbh[1]) {
213 if (flag == NILFS_SB_COMMIT_ALL) {
214 set_buffer_dirty(nilfs->ns_sbh[1]);
215 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
218 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
219 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
220 sbp = nilfs->ns_sbp[1];
223 spin_lock(&nilfs->ns_last_segment_lock);
224 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
225 spin_unlock(&nilfs->ns_last_segment_lock);
231 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
232 struct the_nilfs *nilfs)
234 sector_t nfreeblocks;
236 /* nilfs->ns_sem must be locked by the caller. */
237 nilfs_count_free_blocks(nilfs, &nfreeblocks);
238 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
240 spin_lock(&nilfs->ns_last_segment_lock);
241 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
242 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
243 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
244 spin_unlock(&nilfs->ns_last_segment_lock);
247 struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
250 struct the_nilfs *nilfs = sb->s_fs_info;
251 struct nilfs_super_block **sbp = nilfs->ns_sbp;
253 /* nilfs->ns_sem must be locked by the caller. */
254 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
256 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
257 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
259 nilfs_crit(sb, "superblock broke");
263 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
264 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
268 nilfs_swap_super_block(nilfs);
273 int nilfs_commit_super(struct super_block *sb, int flag)
275 struct the_nilfs *nilfs = sb->s_fs_info;
276 struct nilfs_super_block **sbp = nilfs->ns_sbp;
279 /* nilfs->ns_sem must be locked by the caller. */
280 t = ktime_get_real_seconds();
281 nilfs->ns_sbwtime = t;
282 sbp[0]->s_wtime = cpu_to_le64(t);
284 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
285 (unsigned char *)sbp[0],
287 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
288 sbp[1]->s_wtime = sbp[0]->s_wtime;
290 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
291 (unsigned char *)sbp[1],
294 clear_nilfs_sb_dirty(nilfs);
295 nilfs->ns_flushed_device = 1;
296 /* make sure store to ns_flushed_device cannot be reordered */
298 return nilfs_sync_super(sb, flag);
302 * nilfs_cleanup_super() - write filesystem state for cleanup
303 * @sb: super block instance to be unmounted or degraded to read-only
305 * This function restores state flags in the on-disk super block.
306 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
307 * filesystem was not clean previously.
309 int nilfs_cleanup_super(struct super_block *sb)
311 struct the_nilfs *nilfs = sb->s_fs_info;
312 struct nilfs_super_block **sbp;
313 int flag = NILFS_SB_COMMIT;
316 sbp = nilfs_prepare_super(sb, 0);
318 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
319 nilfs_set_log_cursor(sbp[0], nilfs);
320 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
322 * make the "clean" flag also to the opposite
323 * super block if both super blocks point to
324 * the same checkpoint.
326 sbp[1]->s_state = sbp[0]->s_state;
327 flag = NILFS_SB_COMMIT_ALL;
329 ret = nilfs_commit_super(sb, flag);
335 * nilfs_move_2nd_super - relocate secondary super block
336 * @sb: super block instance
337 * @sb2off: new offset of the secondary super block (in bytes)
339 static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
341 struct the_nilfs *nilfs = sb->s_fs_info;
342 struct buffer_head *nsbh;
343 struct nilfs_super_block *nsbp;
344 sector_t blocknr, newblocknr;
345 unsigned long offset;
346 int sb2i; /* array index of the secondary superblock */
349 /* nilfs->ns_sem must be locked by the caller. */
350 if (nilfs->ns_sbh[1] &&
351 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
353 blocknr = nilfs->ns_sbh[1]->b_blocknr;
354 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
356 blocknr = nilfs->ns_sbh[0]->b_blocknr;
361 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
362 goto out; /* super block location is unchanged */
364 /* Get new super block buffer */
365 newblocknr = sb2off >> nilfs->ns_blocksize_bits;
366 offset = sb2off & (nilfs->ns_blocksize - 1);
367 nsbh = sb_getblk(sb, newblocknr);
370 "unable to move secondary superblock to block %llu",
371 (unsigned long long)newblocknr);
375 nsbp = (void *)nsbh->b_data + offset;
380 * The position of the second superblock only changes by 4KiB,
381 * which is larger than the maximum superblock data size
382 * (= 1KiB), so there is no need to use memmove() to allow
383 * overlap between source and destination.
385 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
388 * Zero fill after copy to avoid overwriting in case of move
389 * within the same block.
391 memset(nsbh->b_data, 0, offset);
392 memset((void *)nsbp + nilfs->ns_sbsize, 0,
393 nsbh->b_size - offset - nilfs->ns_sbsize);
395 memset(nsbh->b_data, 0, nsbh->b_size);
397 set_buffer_uptodate(nsbh);
401 brelse(nilfs->ns_sbh[sb2i]);
402 nilfs->ns_sbh[sb2i] = nsbh;
403 nilfs->ns_sbp[sb2i] = nsbp;
404 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
405 /* secondary super block will be restored to index 1 */
406 nilfs->ns_sbh[1] = nsbh;
407 nilfs->ns_sbp[1] = nsbp;
416 * nilfs_resize_fs - resize the filesystem
417 * @sb: super block instance
418 * @newsize: new size of the filesystem (in bytes)
420 int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
422 struct the_nilfs *nilfs = sb->s_fs_info;
423 struct nilfs_super_block **sbp;
424 __u64 devsize, newnsegs;
429 devsize = bdev_nr_bytes(sb->s_bdev);
430 if (newsize > devsize)
434 * Prevent underflow in second superblock position calculation.
435 * The exact minimum size check is done in nilfs_sufile_resize().
437 if (newsize < 4096) {
443 * Write lock is required to protect some functions depending
444 * on the number of segments, the number of reserved segments,
447 down_write(&nilfs->ns_segctor_sem);
449 sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
450 newnsegs = sb2off >> nilfs->ns_blocksize_bits;
451 do_div(newnsegs, nilfs->ns_blocks_per_segment);
453 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
454 up_write(&nilfs->ns_segctor_sem);
458 ret = nilfs_construct_segment(sb);
462 down_write(&nilfs->ns_sem);
463 nilfs_move_2nd_super(sb, sb2off);
465 sbp = nilfs_prepare_super(sb, 0);
467 nilfs_set_log_cursor(sbp[0], nilfs);
469 * Drop NILFS_RESIZE_FS flag for compatibility with
470 * mount-time resize which may be implemented in a
473 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
475 sbp[0]->s_dev_size = cpu_to_le64(newsize);
476 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
478 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
479 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
481 up_write(&nilfs->ns_sem);
484 * Reset the range of allocatable segments last. This order
485 * is important in the case of expansion because the secondary
486 * superblock must be protected from log write until migration
490 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
495 static void nilfs_put_super(struct super_block *sb)
497 struct the_nilfs *nilfs = sb->s_fs_info;
499 nilfs_detach_log_writer(sb);
501 if (!sb_rdonly(sb)) {
502 down_write(&nilfs->ns_sem);
503 nilfs_cleanup_super(sb);
504 up_write(&nilfs->ns_sem);
507 nilfs_sysfs_delete_device_group(nilfs);
508 iput(nilfs->ns_sufile);
509 iput(nilfs->ns_cpfile);
512 destroy_nilfs(nilfs);
513 sb->s_fs_info = NULL;
516 static int nilfs_sync_fs(struct super_block *sb, int wait)
518 struct the_nilfs *nilfs = sb->s_fs_info;
519 struct nilfs_super_block **sbp;
522 /* This function is called when super block should be written back */
524 err = nilfs_construct_segment(sb);
526 down_write(&nilfs->ns_sem);
527 if (nilfs_sb_dirty(nilfs)) {
528 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
530 nilfs_set_log_cursor(sbp[0], nilfs);
531 nilfs_commit_super(sb, NILFS_SB_COMMIT);
534 up_write(&nilfs->ns_sem);
537 err = nilfs_flush_device(nilfs);
542 int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
543 struct nilfs_root **rootp)
545 struct the_nilfs *nilfs = sb->s_fs_info;
546 struct nilfs_root *root;
547 struct nilfs_checkpoint *raw_cp;
548 struct buffer_head *bh_cp;
551 root = nilfs_find_or_create_root(
552 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
557 goto reuse; /* already attached checkpoint */
559 down_read(&nilfs->ns_segctor_sem);
560 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
562 up_read(&nilfs->ns_segctor_sem);
564 if (err == -ENOENT || err == -EINVAL) {
566 "Invalid checkpoint (checkpoint number=%llu)",
567 (unsigned long long)cno);
573 err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
574 &raw_cp->cp_ifile_inode, &root->ifile);
578 atomic64_set(&root->inodes_count,
579 le64_to_cpu(raw_cp->cp_inodes_count));
580 atomic64_set(&root->blocks_count,
581 le64_to_cpu(raw_cp->cp_blocks_count));
583 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
590 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
592 nilfs_put_root(root);
597 static int nilfs_freeze(struct super_block *sb)
599 struct the_nilfs *nilfs = sb->s_fs_info;
605 /* Mark super block clean */
606 down_write(&nilfs->ns_sem);
607 err = nilfs_cleanup_super(sb);
608 up_write(&nilfs->ns_sem);
612 static int nilfs_unfreeze(struct super_block *sb)
614 struct the_nilfs *nilfs = sb->s_fs_info;
619 down_write(&nilfs->ns_sem);
620 nilfs_setup_super(sb, false);
621 up_write(&nilfs->ns_sem);
625 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
627 struct super_block *sb = dentry->d_sb;
628 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
629 struct the_nilfs *nilfs = root->nilfs;
630 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
631 unsigned long long blocks;
632 unsigned long overhead;
633 unsigned long nrsvblocks;
634 sector_t nfreeblocks;
635 u64 nmaxinodes, nfreeinodes;
639 * Compute all of the segment blocks
641 * The blocks before first segment and after last segment
644 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
645 - nilfs->ns_first_data_block;
646 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
649 * Compute the overhead
651 * When distributing meta data blocks outside segment structure,
652 * We must count them as the overhead.
656 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
660 err = nilfs_ifile_count_free_inodes(root->ifile,
661 &nmaxinodes, &nfreeinodes);
663 nilfs_warn(sb, "failed to count free inodes: err=%d", err);
664 if (err == -ERANGE) {
666 * If nilfs_palloc_count_max_entries() returns
667 * -ERANGE error code then we simply treat
668 * curent inodes count as maximum possible and
669 * zero as free inodes value.
671 nmaxinodes = atomic64_read(&root->inodes_count);
678 buf->f_type = NILFS_SUPER_MAGIC;
679 buf->f_bsize = sb->s_blocksize;
680 buf->f_blocks = blocks - overhead;
681 buf->f_bfree = nfreeblocks;
682 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
683 (buf->f_bfree - nrsvblocks) : 0;
684 buf->f_files = nmaxinodes;
685 buf->f_ffree = nfreeinodes;
686 buf->f_namelen = NILFS_NAME_LEN;
687 buf->f_fsid = u64_to_fsid(id);
692 static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
694 struct super_block *sb = dentry->d_sb;
695 struct the_nilfs *nilfs = sb->s_fs_info;
696 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
698 if (!nilfs_test_opt(nilfs, BARRIER))
699 seq_puts(seq, ",nobarrier");
700 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
701 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
702 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
703 seq_puts(seq, ",errors=panic");
704 if (nilfs_test_opt(nilfs, ERRORS_CONT))
705 seq_puts(seq, ",errors=continue");
706 if (nilfs_test_opt(nilfs, STRICT_ORDER))
707 seq_puts(seq, ",order=strict");
708 if (nilfs_test_opt(nilfs, NORECOVERY))
709 seq_puts(seq, ",norecovery");
710 if (nilfs_test_opt(nilfs, DISCARD))
711 seq_puts(seq, ",discard");
716 static const struct super_operations nilfs_sops = {
717 .alloc_inode = nilfs_alloc_inode,
718 .free_inode = nilfs_free_inode,
719 .dirty_inode = nilfs_dirty_inode,
720 .evict_inode = nilfs_evict_inode,
721 .put_super = nilfs_put_super,
722 .sync_fs = nilfs_sync_fs,
723 .freeze_fs = nilfs_freeze,
724 .unfreeze_fs = nilfs_unfreeze,
725 .statfs = nilfs_statfs,
726 .remount_fs = nilfs_remount,
727 .show_options = nilfs_show_options
731 Opt_err_cont, Opt_err_panic, Opt_err_ro,
732 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
733 Opt_discard, Opt_nodiscard, Opt_err,
736 static match_table_t tokens = {
737 {Opt_err_cont, "errors=continue"},
738 {Opt_err_panic, "errors=panic"},
739 {Opt_err_ro, "errors=remount-ro"},
740 {Opt_barrier, "barrier"},
741 {Opt_nobarrier, "nobarrier"},
742 {Opt_snapshot, "cp=%u"},
743 {Opt_order, "order=%s"},
744 {Opt_norecovery, "norecovery"},
745 {Opt_discard, "discard"},
746 {Opt_nodiscard, "nodiscard"},
750 static int parse_options(char *options, struct super_block *sb, int is_remount)
752 struct the_nilfs *nilfs = sb->s_fs_info;
754 substring_t args[MAX_OPT_ARGS];
759 while ((p = strsep(&options, ",")) != NULL) {
765 token = match_token(p, tokens, args);
768 nilfs_set_opt(nilfs, BARRIER);
771 nilfs_clear_opt(nilfs, BARRIER);
774 if (strcmp(args[0].from, "relaxed") == 0)
775 /* Ordered data semantics */
776 nilfs_clear_opt(nilfs, STRICT_ORDER);
777 else if (strcmp(args[0].from, "strict") == 0)
778 /* Strict in-order semantics */
779 nilfs_set_opt(nilfs, STRICT_ORDER);
784 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
787 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
790 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
795 "\"%s\" option is invalid for remount",
801 nilfs_set_opt(nilfs, NORECOVERY);
804 nilfs_set_opt(nilfs, DISCARD);
807 nilfs_clear_opt(nilfs, DISCARD);
810 nilfs_err(sb, "unrecognized mount option \"%s\"", p);
818 nilfs_set_default_options(struct super_block *sb,
819 struct nilfs_super_block *sbp)
821 struct the_nilfs *nilfs = sb->s_fs_info;
823 nilfs->ns_mount_opt =
824 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
827 static int nilfs_setup_super(struct super_block *sb, int is_mount)
829 struct the_nilfs *nilfs = sb->s_fs_info;
830 struct nilfs_super_block **sbp;
834 /* nilfs->ns_sem must be locked by the caller. */
835 sbp = nilfs_prepare_super(sb, 0);
840 goto skip_mount_setup;
842 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
843 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
845 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
846 nilfs_warn(sb, "mounting fs with errors");
848 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
849 nilfs_warn(sb, "maximal mount count reached");
853 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
855 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
856 sbp[0]->s_mtime = cpu_to_le64(ktime_get_real_seconds());
860 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
861 /* synchronize sbp[1] with sbp[0] */
863 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
864 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
867 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
868 u64 pos, int blocksize,
869 struct buffer_head **pbh)
871 unsigned long long sb_index = pos;
872 unsigned long offset;
874 offset = do_div(sb_index, blocksize);
875 *pbh = sb_bread(sb, sb_index);
878 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
881 int nilfs_store_magic_and_option(struct super_block *sb,
882 struct nilfs_super_block *sbp,
885 struct the_nilfs *nilfs = sb->s_fs_info;
887 sb->s_magic = le16_to_cpu(sbp->s_magic);
889 /* FS independent flags */
890 #ifdef NILFS_ATIME_DISABLE
891 sb->s_flags |= SB_NOATIME;
894 nilfs_set_default_options(sb, sbp);
896 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
897 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
898 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
899 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
901 return !parse_options(data, sb, 0) ? -EINVAL : 0;
904 int nilfs_check_feature_compatibility(struct super_block *sb,
905 struct nilfs_super_block *sbp)
909 features = le64_to_cpu(sbp->s_feature_incompat) &
910 ~NILFS_FEATURE_INCOMPAT_SUPP;
913 "couldn't mount because of unsupported optional features (%llx)",
914 (unsigned long long)features);
917 features = le64_to_cpu(sbp->s_feature_compat_ro) &
918 ~NILFS_FEATURE_COMPAT_RO_SUPP;
919 if (!sb_rdonly(sb) && features) {
921 "couldn't mount RDWR because of unsupported optional features (%llx)",
922 (unsigned long long)features);
928 static int nilfs_get_root_dentry(struct super_block *sb,
929 struct nilfs_root *root,
930 struct dentry **root_dentry)
933 struct dentry *dentry;
936 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
938 ret = PTR_ERR(inode);
939 nilfs_err(sb, "error %d getting root inode", ret);
942 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
944 nilfs_err(sb, "corrupt root inode");
949 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
950 dentry = d_find_alias(inode);
952 dentry = d_make_root(inode);
961 dentry = d_obtain_root(inode);
962 if (IS_ERR(dentry)) {
963 ret = PTR_ERR(dentry);
967 *root_dentry = dentry;
972 nilfs_err(sb, "error %d getting root dentry", ret);
976 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
977 struct dentry **root_dentry)
979 struct the_nilfs *nilfs = s->s_fs_info;
980 struct nilfs_root *root;
983 mutex_lock(&nilfs->ns_snapshot_mount_mutex);
985 down_read(&nilfs->ns_segctor_sem);
986 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
987 up_read(&nilfs->ns_segctor_sem);
989 ret = (ret == -ENOENT) ? -EINVAL : ret;
993 "The specified checkpoint is not a snapshot (checkpoint number=%llu)",
994 (unsigned long long)cno);
999 ret = nilfs_attach_checkpoint(s, cno, false, &root);
1002 "error %d while loading snapshot (checkpoint number=%llu)",
1003 ret, (unsigned long long)cno);
1006 ret = nilfs_get_root_dentry(s, root, root_dentry);
1007 nilfs_put_root(root);
1009 mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
1014 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
1015 * @root_dentry: root dentry of the tree to be shrunk
1017 * This function returns true if the tree was in-use.
1019 static bool nilfs_tree_is_busy(struct dentry *root_dentry)
1021 shrink_dcache_parent(root_dentry);
1022 return d_count(root_dentry) > 1;
1025 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
1027 struct the_nilfs *nilfs = sb->s_fs_info;
1028 struct nilfs_root *root;
1029 struct inode *inode;
1030 struct dentry *dentry;
1033 if (cno > nilfs->ns_cno)
1036 if (cno >= nilfs_last_cno(nilfs))
1037 return true; /* protect recent checkpoints */
1040 root = nilfs_lookup_root(nilfs, cno);
1042 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
1044 dentry = d_find_alias(inode);
1046 ret = nilfs_tree_is_busy(dentry);
1051 nilfs_put_root(root);
1057 * nilfs_fill_super() - initialize a super block instance
1059 * @data: mount options
1060 * @silent: silent mode flag
1062 * This function is called exclusively by nilfs->ns_mount_mutex.
1063 * So, the recovery process is protected from other simultaneous mounts.
1066 nilfs_fill_super(struct super_block *sb, void *data, int silent)
1068 struct the_nilfs *nilfs;
1069 struct nilfs_root *fsroot;
1073 nilfs = alloc_nilfs(sb);
1077 sb->s_fs_info = nilfs;
1079 err = init_nilfs(nilfs, sb, (char *)data);
1083 sb->s_op = &nilfs_sops;
1084 sb->s_export_op = &nilfs_export_ops;
1086 sb->s_time_gran = 1;
1087 sb->s_max_links = NILFS_LINK_MAX;
1089 sb->s_bdi = bdi_get(sb->s_bdev->bd_disk->bdi);
1091 err = load_nilfs(nilfs, sb);
1095 cno = nilfs_last_cno(nilfs);
1096 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
1099 "error %d while loading last checkpoint (checkpoint number=%llu)",
1100 err, (unsigned long long)cno);
1104 if (!sb_rdonly(sb)) {
1105 err = nilfs_attach_log_writer(sb, fsroot);
1107 goto failed_checkpoint;
1110 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
1112 goto failed_segctor;
1114 nilfs_put_root(fsroot);
1116 if (!sb_rdonly(sb)) {
1117 down_write(&nilfs->ns_sem);
1118 nilfs_setup_super(sb, true);
1119 up_write(&nilfs->ns_sem);
1125 nilfs_detach_log_writer(sb);
1128 nilfs_put_root(fsroot);
1131 nilfs_sysfs_delete_device_group(nilfs);
1132 iput(nilfs->ns_sufile);
1133 iput(nilfs->ns_cpfile);
1134 iput(nilfs->ns_dat);
1137 destroy_nilfs(nilfs);
1141 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
1143 struct the_nilfs *nilfs = sb->s_fs_info;
1144 unsigned long old_sb_flags;
1145 unsigned long old_mount_opt;
1148 sync_filesystem(sb);
1149 old_sb_flags = sb->s_flags;
1150 old_mount_opt = nilfs->ns_mount_opt;
1152 if (!parse_options(data, sb, 1)) {
1156 sb->s_flags = (sb->s_flags & ~SB_POSIXACL);
1160 if (!nilfs_valid_fs(nilfs)) {
1162 "couldn't remount because the filesystem is in an incomplete recovery state");
1166 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1168 if (*flags & SB_RDONLY) {
1169 sb->s_flags |= SB_RDONLY;
1172 * Remounting a valid RW partition RDONLY, so set
1173 * the RDONLY flag and then mark the partition as valid again.
1175 down_write(&nilfs->ns_sem);
1176 nilfs_cleanup_super(sb);
1177 up_write(&nilfs->ns_sem);
1180 struct nilfs_root *root;
1183 * Mounting a RDONLY partition read-write, so reread and
1184 * store the current valid flag. (It may have been changed
1185 * by fsck since we originally mounted the partition.)
1187 down_read(&nilfs->ns_sem);
1188 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1189 ~NILFS_FEATURE_COMPAT_RO_SUPP;
1190 up_read(&nilfs->ns_sem);
1193 "couldn't remount RDWR because of unsupported optional features (%llx)",
1194 (unsigned long long)features);
1199 sb->s_flags &= ~SB_RDONLY;
1201 root = NILFS_I(d_inode(sb->s_root))->i_root;
1202 err = nilfs_attach_log_writer(sb, root);
1206 down_write(&nilfs->ns_sem);
1207 nilfs_setup_super(sb, true);
1208 up_write(&nilfs->ns_sem);
1214 sb->s_flags = old_sb_flags;
1215 nilfs->ns_mount_opt = old_mount_opt;
1219 struct nilfs_super_data {
1224 static int nilfs_parse_snapshot_option(const char *option,
1225 const substring_t *arg,
1226 struct nilfs_super_data *sd)
1228 unsigned long long val;
1229 const char *msg = NULL;
1232 if (!(sd->flags & SB_RDONLY)) {
1233 msg = "read-only option is not specified";
1237 err = kstrtoull(arg->from, 0, &val);
1240 msg = "too large checkpoint number";
1242 msg = "malformed argument";
1244 } else if (val == 0) {
1245 msg = "invalid checkpoint number 0";
1252 nilfs_err(NULL, "invalid option \"%s\": %s", option, msg);
1257 * nilfs_identify - pre-read mount options needed to identify mount instance
1258 * @data: mount options
1259 * @sd: nilfs_super_data
1261 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1263 char *p, *options = data;
1264 substring_t args[MAX_OPT_ARGS];
1269 p = strsep(&options, ",");
1270 if (p != NULL && *p) {
1271 token = match_token(p, tokens, args);
1272 if (token == Opt_snapshot)
1273 ret = nilfs_parse_snapshot_option(p, &args[0],
1278 BUG_ON(options == data);
1279 *(options - 1) = ',';
1284 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1286 s->s_dev = *(dev_t *)data;
1290 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1292 return !(s->s_iflags & SB_I_RETIRED) && s->s_dev == *(dev_t *)data;
1295 static struct dentry *
1296 nilfs_mount(struct file_system_type *fs_type, int flags,
1297 const char *dev_name, void *data)
1299 struct nilfs_super_data sd = { .flags = flags };
1300 struct super_block *s;
1304 if (nilfs_identify(data, &sd))
1305 return ERR_PTR(-EINVAL);
1307 err = lookup_bdev(dev_name, &dev);
1309 return ERR_PTR(err);
1311 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
1318 * We drop s_umount here because we need to open the bdev and
1319 * bdev->open_mutex ranks above s_umount (blkdev_put() ->
1320 * __invalidate_device()). It is safe because we have active sb
1321 * reference and SB_BORN is not set yet.
1323 up_write(&s->s_umount);
1324 err = setup_bdev_super(s, flags, NULL);
1325 down_write(&s->s_umount);
1327 err = nilfs_fill_super(s, data,
1328 flags & SB_SILENT ? 1 : 0);
1332 s->s_flags |= SB_ACTIVE;
1333 } else if (!sd.cno) {
1334 if (nilfs_tree_is_busy(s->s_root)) {
1335 if ((flags ^ s->s_flags) & SB_RDONLY) {
1337 "the device already has a %s mount.",
1338 sb_rdonly(s) ? "read-only" : "read/write");
1344 * Try remount to setup mount states if the current
1345 * tree is not mounted and only snapshots use this sb.
1347 err = nilfs_remount(s, &flags, data);
1354 struct dentry *root_dentry;
1356 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1362 return dget(s->s_root);
1365 deactivate_locked_super(s);
1366 return ERR_PTR(err);
1369 struct file_system_type nilfs_fs_type = {
1370 .owner = THIS_MODULE,
1372 .mount = nilfs_mount,
1373 .kill_sb = kill_block_super,
1374 .fs_flags = FS_REQUIRES_DEV,
1376 MODULE_ALIAS_FS("nilfs2");
1378 static void nilfs_inode_init_once(void *obj)
1380 struct nilfs_inode_info *ii = obj;
1382 INIT_LIST_HEAD(&ii->i_dirty);
1383 #ifdef CONFIG_NILFS_XATTR
1384 init_rwsem(&ii->xattr_sem);
1386 inode_init_once(&ii->vfs_inode);
1389 static void nilfs_segbuf_init_once(void *obj)
1391 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1394 static void nilfs_destroy_cachep(void)
1397 * Make sure all delayed rcu free inodes are flushed before we
1402 kmem_cache_destroy(nilfs_inode_cachep);
1403 kmem_cache_destroy(nilfs_transaction_cachep);
1404 kmem_cache_destroy(nilfs_segbuf_cachep);
1405 kmem_cache_destroy(nilfs_btree_path_cache);
1408 static int __init nilfs_init_cachep(void)
1410 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1411 sizeof(struct nilfs_inode_info), 0,
1412 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
1413 nilfs_inode_init_once);
1414 if (!nilfs_inode_cachep)
1417 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1418 sizeof(struct nilfs_transaction_info), 0,
1419 SLAB_RECLAIM_ACCOUNT, NULL);
1420 if (!nilfs_transaction_cachep)
1423 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1424 sizeof(struct nilfs_segment_buffer), 0,
1425 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1426 if (!nilfs_segbuf_cachep)
1429 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1430 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1432 if (!nilfs_btree_path_cache)
1438 nilfs_destroy_cachep();
1442 static int __init init_nilfs_fs(void)
1446 err = nilfs_init_cachep();
1450 err = nilfs_sysfs_init();
1454 err = register_filesystem(&nilfs_fs_type);
1456 goto deinit_sysfs_entry;
1458 printk(KERN_INFO "NILFS version 2 loaded\n");
1464 nilfs_destroy_cachep();
1469 static void __exit exit_nilfs_fs(void)
1471 nilfs_destroy_cachep();
1473 unregister_filesystem(&nilfs_fs_type);
1476 module_init(init_nilfs_fs)
1477 module_exit(exit_nilfs_fs)