1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * super.c - NILFS module and super block management.
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Ryusuke Konishi.
8 */
9 /*
10 * linux/fs/ext2/super.c
11 *
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)
16 *
17 * from
18 *
19 * linux/fs/minix/inode.c
20 *
21 * Copyright (C) 1991, 1992 Linus Torvalds
22 *
23 * Big-endian to little-endian byte-swapping/bitmaps by
24 * David S. Miller (davem@caip.rutgers.edu), 1995
25 */
26
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 "nilfs.h"
39 #include "export.h"
40 #include "mdt.h"
41 #include "alloc.h"
42 #include "btree.h"
43 #include "btnode.h"
44 #include "page.h"
45 #include "cpfile.h"
46 #include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
47 #include "ifile.h"
48 #include "dat.h"
49 #include "segment.h"
50 #include "segbuf.h"
51
52 MODULE_AUTHOR("NTT Corp.");
53 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
54 "(NILFS)");
55 MODULE_LICENSE("GPL");
56
57 static struct kmem_cache *nilfs_inode_cachep;
58 struct kmem_cache *nilfs_transaction_cachep;
59 struct kmem_cache *nilfs_segbuf_cachep;
60 struct kmem_cache *nilfs_btree_path_cache;
61
62 static int nilfs_setup_super(struct super_block *sb, int is_mount);
63 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
64
__nilfs_msg(struct super_block * sb,const char * fmt,...)65 void __nilfs_msg(struct super_block *sb, const char *fmt, ...)
66 {
67 struct va_format vaf;
68 va_list args;
69 int level;
70
71 va_start(args, fmt);
72
73 level = printk_get_level(fmt);
74 vaf.fmt = printk_skip_level(fmt);
75 vaf.va = &args;
76
77 if (sb)
78 printk("%c%cNILFS (%s): %pV\n",
79 KERN_SOH_ASCII, level, sb->s_id, &vaf);
80 else
81 printk("%c%cNILFS: %pV\n",
82 KERN_SOH_ASCII, level, &vaf);
83
84 va_end(args);
85 }
86
nilfs_set_error(struct super_block * sb)87 static void nilfs_set_error(struct super_block *sb)
88 {
89 struct the_nilfs *nilfs = sb->s_fs_info;
90 struct nilfs_super_block **sbp;
91
92 down_write(&nilfs->ns_sem);
93 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
94 nilfs->ns_mount_state |= NILFS_ERROR_FS;
95 sbp = nilfs_prepare_super(sb, 0);
96 if (likely(sbp)) {
97 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
98 if (sbp[1])
99 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
100 nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
101 }
102 }
103 up_write(&nilfs->ns_sem);
104 }
105
106 /**
107 * __nilfs_error() - report failure condition on a filesystem
108 *
109 * __nilfs_error() sets an ERROR_FS flag on the superblock as well as
110 * reporting an error message. This function should be called when
111 * NILFS detects incoherences or defects of meta data on disk.
112 *
113 * This implements the body of nilfs_error() macro. Normally,
114 * nilfs_error() should be used. As for sustainable errors such as a
115 * single-shot I/O error, nilfs_err() should be used instead.
116 *
117 * Callers should not add a trailing newline since this will do it.
118 */
__nilfs_error(struct super_block * sb,const char * function,const char * fmt,...)119 void __nilfs_error(struct super_block *sb, const char *function,
120 const char *fmt, ...)
121 {
122 struct the_nilfs *nilfs = sb->s_fs_info;
123 struct va_format vaf;
124 va_list args;
125
126 va_start(args, fmt);
127
128 vaf.fmt = fmt;
129 vaf.va = &args;
130
131 printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
132 sb->s_id, function, &vaf);
133
134 va_end(args);
135
136 if (!sb_rdonly(sb)) {
137 nilfs_set_error(sb);
138
139 if (nilfs_test_opt(nilfs, ERRORS_RO)) {
140 printk(KERN_CRIT "Remounting filesystem read-only\n");
141 sb->s_flags |= SB_RDONLY;
142 }
143 }
144
145 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
146 panic("NILFS (device %s): panic forced after error\n",
147 sb->s_id);
148 }
149
nilfs_alloc_inode(struct super_block * sb)150 struct inode *nilfs_alloc_inode(struct super_block *sb)
151 {
152 struct nilfs_inode_info *ii;
153
154 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
155 if (!ii)
156 return NULL;
157 ii->i_bh = NULL;
158 ii->i_state = 0;
159 ii->i_cno = 0;
160 ii->i_assoc_inode = NULL;
161 ii->i_bmap = &ii->i_bmap_data;
162 return &ii->vfs_inode;
163 }
164
nilfs_free_inode(struct inode * inode)165 static void nilfs_free_inode(struct inode *inode)
166 {
167 if (nilfs_is_metadata_file_inode(inode))
168 nilfs_mdt_destroy(inode);
169
170 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
171 }
172
nilfs_sync_super(struct super_block * sb,int flag)173 static int nilfs_sync_super(struct super_block *sb, int flag)
174 {
175 struct the_nilfs *nilfs = sb->s_fs_info;
176 int err;
177
178 retry:
179 set_buffer_dirty(nilfs->ns_sbh[0]);
180 if (nilfs_test_opt(nilfs, BARRIER)) {
181 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
182 REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
183 } else {
184 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
185 }
186
187 if (unlikely(err)) {
188 nilfs_err(sb, "unable to write superblock: err=%d", err);
189 if (err == -EIO && nilfs->ns_sbh[1]) {
190 /*
191 * sbp[0] points to newer log than sbp[1],
192 * so copy sbp[0] to sbp[1] to take over sbp[0].
193 */
194 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
195 nilfs->ns_sbsize);
196 nilfs_fall_back_super_block(nilfs);
197 goto retry;
198 }
199 } else {
200 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
201
202 nilfs->ns_sbwcount++;
203
204 /*
205 * The latest segment becomes trailable from the position
206 * written in superblock.
207 */
208 clear_nilfs_discontinued(nilfs);
209
210 /* update GC protection for recent segments */
211 if (nilfs->ns_sbh[1]) {
212 if (flag == NILFS_SB_COMMIT_ALL) {
213 set_buffer_dirty(nilfs->ns_sbh[1]);
214 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
215 goto out;
216 }
217 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
218 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
219 sbp = nilfs->ns_sbp[1];
220 }
221
222 spin_lock(&nilfs->ns_last_segment_lock);
223 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
224 spin_unlock(&nilfs->ns_last_segment_lock);
225 }
226 out:
227 return err;
228 }
229
nilfs_set_log_cursor(struct nilfs_super_block * sbp,struct the_nilfs * nilfs)230 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
231 struct the_nilfs *nilfs)
232 {
233 sector_t nfreeblocks;
234
235 /* nilfs->ns_sem must be locked by the caller. */
236 nilfs_count_free_blocks(nilfs, &nfreeblocks);
237 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
238
239 spin_lock(&nilfs->ns_last_segment_lock);
240 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
241 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
242 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
243 spin_unlock(&nilfs->ns_last_segment_lock);
244 }
245
nilfs_prepare_super(struct super_block * sb,int flip)246 struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
247 int flip)
248 {
249 struct the_nilfs *nilfs = sb->s_fs_info;
250 struct nilfs_super_block **sbp = nilfs->ns_sbp;
251
252 /* nilfs->ns_sem must be locked by the caller. */
253 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
254 if (sbp[1] &&
255 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
256 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
257 } else {
258 nilfs_crit(sb, "superblock broke");
259 return NULL;
260 }
261 } else if (sbp[1] &&
262 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
263 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
264 }
265
266 if (flip && sbp[1])
267 nilfs_swap_super_block(nilfs);
268
269 return sbp;
270 }
271
nilfs_commit_super(struct super_block * sb,int flag)272 int nilfs_commit_super(struct super_block *sb, int flag)
273 {
274 struct the_nilfs *nilfs = sb->s_fs_info;
275 struct nilfs_super_block **sbp = nilfs->ns_sbp;
276 time64_t t;
277
278 /* nilfs->ns_sem must be locked by the caller. */
279 t = ktime_get_real_seconds();
280 nilfs->ns_sbwtime = t;
281 sbp[0]->s_wtime = cpu_to_le64(t);
282 sbp[0]->s_sum = 0;
283 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
284 (unsigned char *)sbp[0],
285 nilfs->ns_sbsize));
286 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
287 sbp[1]->s_wtime = sbp[0]->s_wtime;
288 sbp[1]->s_sum = 0;
289 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
290 (unsigned char *)sbp[1],
291 nilfs->ns_sbsize));
292 }
293 clear_nilfs_sb_dirty(nilfs);
294 nilfs->ns_flushed_device = 1;
295 /* make sure store to ns_flushed_device cannot be reordered */
296 smp_wmb();
297 return nilfs_sync_super(sb, flag);
298 }
299
300 /**
301 * nilfs_cleanup_super() - write filesystem state for cleanup
302 * @sb: super block instance to be unmounted or degraded to read-only
303 *
304 * This function restores state flags in the on-disk super block.
305 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
306 * filesystem was not clean previously.
307 */
nilfs_cleanup_super(struct super_block * sb)308 int nilfs_cleanup_super(struct super_block *sb)
309 {
310 struct the_nilfs *nilfs = sb->s_fs_info;
311 struct nilfs_super_block **sbp;
312 int flag = NILFS_SB_COMMIT;
313 int ret = -EIO;
314
315 sbp = nilfs_prepare_super(sb, 0);
316 if (sbp) {
317 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
318 nilfs_set_log_cursor(sbp[0], nilfs);
319 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
320 /*
321 * make the "clean" flag also to the opposite
322 * super block if both super blocks point to
323 * the same checkpoint.
324 */
325 sbp[1]->s_state = sbp[0]->s_state;
326 flag = NILFS_SB_COMMIT_ALL;
327 }
328 ret = nilfs_commit_super(sb, flag);
329 }
330 return ret;
331 }
332
333 /**
334 * nilfs_move_2nd_super - relocate secondary super block
335 * @sb: super block instance
336 * @sb2off: new offset of the secondary super block (in bytes)
337 */
nilfs_move_2nd_super(struct super_block * sb,loff_t sb2off)338 static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
339 {
340 struct the_nilfs *nilfs = sb->s_fs_info;
341 struct buffer_head *nsbh;
342 struct nilfs_super_block *nsbp;
343 sector_t blocknr, newblocknr;
344 unsigned long offset;
345 int sb2i; /* array index of the secondary superblock */
346 int ret = 0;
347
348 /* nilfs->ns_sem must be locked by the caller. */
349 if (nilfs->ns_sbh[1] &&
350 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
351 sb2i = 1;
352 blocknr = nilfs->ns_sbh[1]->b_blocknr;
353 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
354 sb2i = 0;
355 blocknr = nilfs->ns_sbh[0]->b_blocknr;
356 } else {
357 sb2i = -1;
358 blocknr = 0;
359 }
360 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
361 goto out; /* super block location is unchanged */
362
363 /* Get new super block buffer */
364 newblocknr = sb2off >> nilfs->ns_blocksize_bits;
365 offset = sb2off & (nilfs->ns_blocksize - 1);
366 nsbh = sb_getblk(sb, newblocknr);
367 if (!nsbh) {
368 nilfs_warn(sb,
369 "unable to move secondary superblock to block %llu",
370 (unsigned long long)newblocknr);
371 ret = -EIO;
372 goto out;
373 }
374 nsbp = (void *)nsbh->b_data + offset;
375 memset(nsbp, 0, nilfs->ns_blocksize);
376
377 if (sb2i >= 0) {
378 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
379 brelse(nilfs->ns_sbh[sb2i]);
380 nilfs->ns_sbh[sb2i] = nsbh;
381 nilfs->ns_sbp[sb2i] = nsbp;
382 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
383 /* secondary super block will be restored to index 1 */
384 nilfs->ns_sbh[1] = nsbh;
385 nilfs->ns_sbp[1] = nsbp;
386 } else {
387 brelse(nsbh);
388 }
389 out:
390 return ret;
391 }
392
393 /**
394 * nilfs_resize_fs - resize the filesystem
395 * @sb: super block instance
396 * @newsize: new size of the filesystem (in bytes)
397 */
nilfs_resize_fs(struct super_block * sb,__u64 newsize)398 int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
399 {
400 struct the_nilfs *nilfs = sb->s_fs_info;
401 struct nilfs_super_block **sbp;
402 __u64 devsize, newnsegs;
403 loff_t sb2off;
404 int ret;
405
406 ret = -ERANGE;
407 devsize = i_size_read(sb->s_bdev->bd_inode);
408 if (newsize > devsize)
409 goto out;
410
411 /*
412 * Write lock is required to protect some functions depending
413 * on the number of segments, the number of reserved segments,
414 * and so forth.
415 */
416 down_write(&nilfs->ns_segctor_sem);
417
418 sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
419 newnsegs = sb2off >> nilfs->ns_blocksize_bits;
420 do_div(newnsegs, nilfs->ns_blocks_per_segment);
421
422 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
423 up_write(&nilfs->ns_segctor_sem);
424 if (ret < 0)
425 goto out;
426
427 ret = nilfs_construct_segment(sb);
428 if (ret < 0)
429 goto out;
430
431 down_write(&nilfs->ns_sem);
432 nilfs_move_2nd_super(sb, sb2off);
433 ret = -EIO;
434 sbp = nilfs_prepare_super(sb, 0);
435 if (likely(sbp)) {
436 nilfs_set_log_cursor(sbp[0], nilfs);
437 /*
438 * Drop NILFS_RESIZE_FS flag for compatibility with
439 * mount-time resize which may be implemented in a
440 * future release.
441 */
442 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
443 ~NILFS_RESIZE_FS);
444 sbp[0]->s_dev_size = cpu_to_le64(newsize);
445 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
446 if (sbp[1])
447 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
448 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
449 }
450 up_write(&nilfs->ns_sem);
451
452 /*
453 * Reset the range of allocatable segments last. This order
454 * is important in the case of expansion because the secondary
455 * superblock must be protected from log write until migration
456 * completes.
457 */
458 if (!ret)
459 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
460 out:
461 return ret;
462 }
463
nilfs_put_super(struct super_block * sb)464 static void nilfs_put_super(struct super_block *sb)
465 {
466 struct the_nilfs *nilfs = sb->s_fs_info;
467
468 nilfs_detach_log_writer(sb);
469
470 if (!sb_rdonly(sb)) {
471 down_write(&nilfs->ns_sem);
472 nilfs_cleanup_super(sb);
473 up_write(&nilfs->ns_sem);
474 }
475
476 iput(nilfs->ns_sufile);
477 iput(nilfs->ns_cpfile);
478 iput(nilfs->ns_dat);
479
480 destroy_nilfs(nilfs);
481 sb->s_fs_info = NULL;
482 }
483
nilfs_sync_fs(struct super_block * sb,int wait)484 static int nilfs_sync_fs(struct super_block *sb, int wait)
485 {
486 struct the_nilfs *nilfs = sb->s_fs_info;
487 struct nilfs_super_block **sbp;
488 int err = 0;
489
490 /* This function is called when super block should be written back */
491 if (wait)
492 err = nilfs_construct_segment(sb);
493
494 down_write(&nilfs->ns_sem);
495 if (nilfs_sb_dirty(nilfs)) {
496 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
497 if (likely(sbp)) {
498 nilfs_set_log_cursor(sbp[0], nilfs);
499 nilfs_commit_super(sb, NILFS_SB_COMMIT);
500 }
501 }
502 up_write(&nilfs->ns_sem);
503
504 if (!err)
505 err = nilfs_flush_device(nilfs);
506
507 return err;
508 }
509
nilfs_attach_checkpoint(struct super_block * sb,__u64 cno,int curr_mnt,struct nilfs_root ** rootp)510 int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
511 struct nilfs_root **rootp)
512 {
513 struct the_nilfs *nilfs = sb->s_fs_info;
514 struct nilfs_root *root;
515 struct nilfs_checkpoint *raw_cp;
516 struct buffer_head *bh_cp;
517 int err = -ENOMEM;
518
519 root = nilfs_find_or_create_root(
520 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
521 if (!root)
522 return err;
523
524 if (root->ifile)
525 goto reuse; /* already attached checkpoint */
526
527 down_read(&nilfs->ns_segctor_sem);
528 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
529 &bh_cp);
530 up_read(&nilfs->ns_segctor_sem);
531 if (unlikely(err)) {
532 if (err == -ENOENT || err == -EINVAL) {
533 nilfs_err(sb,
534 "Invalid checkpoint (checkpoint number=%llu)",
535 (unsigned long long)cno);
536 err = -EINVAL;
537 }
538 goto failed;
539 }
540
541 err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
542 &raw_cp->cp_ifile_inode, &root->ifile);
543 if (err)
544 goto failed_bh;
545
546 atomic64_set(&root->inodes_count,
547 le64_to_cpu(raw_cp->cp_inodes_count));
548 atomic64_set(&root->blocks_count,
549 le64_to_cpu(raw_cp->cp_blocks_count));
550
551 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
552
553 reuse:
554 *rootp = root;
555 return 0;
556
557 failed_bh:
558 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
559 failed:
560 nilfs_put_root(root);
561
562 return err;
563 }
564
nilfs_freeze(struct super_block * sb)565 static int nilfs_freeze(struct super_block *sb)
566 {
567 struct the_nilfs *nilfs = sb->s_fs_info;
568 int err;
569
570 if (sb_rdonly(sb))
571 return 0;
572
573 /* Mark super block clean */
574 down_write(&nilfs->ns_sem);
575 err = nilfs_cleanup_super(sb);
576 up_write(&nilfs->ns_sem);
577 return err;
578 }
579
nilfs_unfreeze(struct super_block * sb)580 static int nilfs_unfreeze(struct super_block *sb)
581 {
582 struct the_nilfs *nilfs = sb->s_fs_info;
583
584 if (sb_rdonly(sb))
585 return 0;
586
587 down_write(&nilfs->ns_sem);
588 nilfs_setup_super(sb, false);
589 up_write(&nilfs->ns_sem);
590 return 0;
591 }
592
nilfs_statfs(struct dentry * dentry,struct kstatfs * buf)593 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
594 {
595 struct super_block *sb = dentry->d_sb;
596 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
597 struct the_nilfs *nilfs = root->nilfs;
598 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
599 unsigned long long blocks;
600 unsigned long overhead;
601 unsigned long nrsvblocks;
602 sector_t nfreeblocks;
603 u64 nmaxinodes, nfreeinodes;
604 int err;
605
606 /*
607 * Compute all of the segment blocks
608 *
609 * The blocks before first segment and after last segment
610 * are excluded.
611 */
612 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
613 - nilfs->ns_first_data_block;
614 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
615
616 /*
617 * Compute the overhead
618 *
619 * When distributing meta data blocks outside segment structure,
620 * We must count them as the overhead.
621 */
622 overhead = 0;
623
624 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
625 if (unlikely(err))
626 return err;
627
628 err = nilfs_ifile_count_free_inodes(root->ifile,
629 &nmaxinodes, &nfreeinodes);
630 if (unlikely(err)) {
631 nilfs_warn(sb, "failed to count free inodes: err=%d", err);
632 if (err == -ERANGE) {
633 /*
634 * If nilfs_palloc_count_max_entries() returns
635 * -ERANGE error code then we simply treat
636 * curent inodes count as maximum possible and
637 * zero as free inodes value.
638 */
639 nmaxinodes = atomic64_read(&root->inodes_count);
640 nfreeinodes = 0;
641 err = 0;
642 } else
643 return err;
644 }
645
646 buf->f_type = NILFS_SUPER_MAGIC;
647 buf->f_bsize = sb->s_blocksize;
648 buf->f_blocks = blocks - overhead;
649 buf->f_bfree = nfreeblocks;
650 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
651 (buf->f_bfree - nrsvblocks) : 0;
652 buf->f_files = nmaxinodes;
653 buf->f_ffree = nfreeinodes;
654 buf->f_namelen = NILFS_NAME_LEN;
655 buf->f_fsid = u64_to_fsid(id);
656
657 return 0;
658 }
659
nilfs_show_options(struct seq_file * seq,struct dentry * dentry)660 static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
661 {
662 struct super_block *sb = dentry->d_sb;
663 struct the_nilfs *nilfs = sb->s_fs_info;
664 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
665
666 if (!nilfs_test_opt(nilfs, BARRIER))
667 seq_puts(seq, ",nobarrier");
668 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
669 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
670 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
671 seq_puts(seq, ",errors=panic");
672 if (nilfs_test_opt(nilfs, ERRORS_CONT))
673 seq_puts(seq, ",errors=continue");
674 if (nilfs_test_opt(nilfs, STRICT_ORDER))
675 seq_puts(seq, ",order=strict");
676 if (nilfs_test_opt(nilfs, NORECOVERY))
677 seq_puts(seq, ",norecovery");
678 if (nilfs_test_opt(nilfs, DISCARD))
679 seq_puts(seq, ",discard");
680
681 return 0;
682 }
683
684 static const struct super_operations nilfs_sops = {
685 .alloc_inode = nilfs_alloc_inode,
686 .free_inode = nilfs_free_inode,
687 .dirty_inode = nilfs_dirty_inode,
688 .evict_inode = nilfs_evict_inode,
689 .put_super = nilfs_put_super,
690 .sync_fs = nilfs_sync_fs,
691 .freeze_fs = nilfs_freeze,
692 .unfreeze_fs = nilfs_unfreeze,
693 .statfs = nilfs_statfs,
694 .remount_fs = nilfs_remount,
695 .show_options = nilfs_show_options
696 };
697
698 enum {
699 Opt_err_cont, Opt_err_panic, Opt_err_ro,
700 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
701 Opt_discard, Opt_nodiscard, Opt_err,
702 };
703
704 static match_table_t tokens = {
705 {Opt_err_cont, "errors=continue"},
706 {Opt_err_panic, "errors=panic"},
707 {Opt_err_ro, "errors=remount-ro"},
708 {Opt_barrier, "barrier"},
709 {Opt_nobarrier, "nobarrier"},
710 {Opt_snapshot, "cp=%u"},
711 {Opt_order, "order=%s"},
712 {Opt_norecovery, "norecovery"},
713 {Opt_discard, "discard"},
714 {Opt_nodiscard, "nodiscard"},
715 {Opt_err, NULL}
716 };
717
parse_options(char * options,struct super_block * sb,int is_remount)718 static int parse_options(char *options, struct super_block *sb, int is_remount)
719 {
720 struct the_nilfs *nilfs = sb->s_fs_info;
721 char *p;
722 substring_t args[MAX_OPT_ARGS];
723
724 if (!options)
725 return 1;
726
727 while ((p = strsep(&options, ",")) != NULL) {
728 int token;
729
730 if (!*p)
731 continue;
732
733 token = match_token(p, tokens, args);
734 switch (token) {
735 case Opt_barrier:
736 nilfs_set_opt(nilfs, BARRIER);
737 break;
738 case Opt_nobarrier:
739 nilfs_clear_opt(nilfs, BARRIER);
740 break;
741 case Opt_order:
742 if (strcmp(args[0].from, "relaxed") == 0)
743 /* Ordered data semantics */
744 nilfs_clear_opt(nilfs, STRICT_ORDER);
745 else if (strcmp(args[0].from, "strict") == 0)
746 /* Strict in-order semantics */
747 nilfs_set_opt(nilfs, STRICT_ORDER);
748 else
749 return 0;
750 break;
751 case Opt_err_panic:
752 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
753 break;
754 case Opt_err_ro:
755 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
756 break;
757 case Opt_err_cont:
758 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
759 break;
760 case Opt_snapshot:
761 if (is_remount) {
762 nilfs_err(sb,
763 "\"%s\" option is invalid for remount",
764 p);
765 return 0;
766 }
767 break;
768 case Opt_norecovery:
769 nilfs_set_opt(nilfs, NORECOVERY);
770 break;
771 case Opt_discard:
772 nilfs_set_opt(nilfs, DISCARD);
773 break;
774 case Opt_nodiscard:
775 nilfs_clear_opt(nilfs, DISCARD);
776 break;
777 default:
778 nilfs_err(sb, "unrecognized mount option \"%s\"", p);
779 return 0;
780 }
781 }
782 return 1;
783 }
784
785 static inline void
nilfs_set_default_options(struct super_block * sb,struct nilfs_super_block * sbp)786 nilfs_set_default_options(struct super_block *sb,
787 struct nilfs_super_block *sbp)
788 {
789 struct the_nilfs *nilfs = sb->s_fs_info;
790
791 nilfs->ns_mount_opt =
792 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
793 }
794
nilfs_setup_super(struct super_block * sb,int is_mount)795 static int nilfs_setup_super(struct super_block *sb, int is_mount)
796 {
797 struct the_nilfs *nilfs = sb->s_fs_info;
798 struct nilfs_super_block **sbp;
799 int max_mnt_count;
800 int mnt_count;
801
802 /* nilfs->ns_sem must be locked by the caller. */
803 sbp = nilfs_prepare_super(sb, 0);
804 if (!sbp)
805 return -EIO;
806
807 if (!is_mount)
808 goto skip_mount_setup;
809
810 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
811 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
812
813 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
814 nilfs_warn(sb, "mounting fs with errors");
815 #if 0
816 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
817 nilfs_warn(sb, "maximal mount count reached");
818 #endif
819 }
820 if (!max_mnt_count)
821 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
822
823 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
824 sbp[0]->s_mtime = cpu_to_le64(ktime_get_real_seconds());
825
826 skip_mount_setup:
827 sbp[0]->s_state =
828 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
829 /* synchronize sbp[1] with sbp[0] */
830 if (sbp[1])
831 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
832 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
833 }
834
nilfs_read_super_block(struct super_block * sb,u64 pos,int blocksize,struct buffer_head ** pbh)835 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
836 u64 pos, int blocksize,
837 struct buffer_head **pbh)
838 {
839 unsigned long long sb_index = pos;
840 unsigned long offset;
841
842 offset = do_div(sb_index, blocksize);
843 *pbh = sb_bread(sb, sb_index);
844 if (!*pbh)
845 return NULL;
846 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
847 }
848
nilfs_store_magic_and_option(struct super_block * sb,struct nilfs_super_block * sbp,char * data)849 int nilfs_store_magic_and_option(struct super_block *sb,
850 struct nilfs_super_block *sbp,
851 char *data)
852 {
853 struct the_nilfs *nilfs = sb->s_fs_info;
854
855 sb->s_magic = le16_to_cpu(sbp->s_magic);
856
857 /* FS independent flags */
858 #ifdef NILFS_ATIME_DISABLE
859 sb->s_flags |= SB_NOATIME;
860 #endif
861
862 nilfs_set_default_options(sb, sbp);
863
864 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
865 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
866 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
867 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
868
869 return !parse_options(data, sb, 0) ? -EINVAL : 0;
870 }
871
nilfs_check_feature_compatibility(struct super_block * sb,struct nilfs_super_block * sbp)872 int nilfs_check_feature_compatibility(struct super_block *sb,
873 struct nilfs_super_block *sbp)
874 {
875 __u64 features;
876
877 features = le64_to_cpu(sbp->s_feature_incompat) &
878 ~NILFS_FEATURE_INCOMPAT_SUPP;
879 if (features) {
880 nilfs_err(sb,
881 "couldn't mount because of unsupported optional features (%llx)",
882 (unsigned long long)features);
883 return -EINVAL;
884 }
885 features = le64_to_cpu(sbp->s_feature_compat_ro) &
886 ~NILFS_FEATURE_COMPAT_RO_SUPP;
887 if (!sb_rdonly(sb) && features) {
888 nilfs_err(sb,
889 "couldn't mount RDWR because of unsupported optional features (%llx)",
890 (unsigned long long)features);
891 return -EINVAL;
892 }
893 return 0;
894 }
895
nilfs_get_root_dentry(struct super_block * sb,struct nilfs_root * root,struct dentry ** root_dentry)896 static int nilfs_get_root_dentry(struct super_block *sb,
897 struct nilfs_root *root,
898 struct dentry **root_dentry)
899 {
900 struct inode *inode;
901 struct dentry *dentry;
902 int ret = 0;
903
904 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
905 if (IS_ERR(inode)) {
906 ret = PTR_ERR(inode);
907 nilfs_err(sb, "error %d getting root inode", ret);
908 goto out;
909 }
910 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
911 iput(inode);
912 nilfs_err(sb, "corrupt root inode");
913 ret = -EINVAL;
914 goto out;
915 }
916
917 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
918 dentry = d_find_alias(inode);
919 if (!dentry) {
920 dentry = d_make_root(inode);
921 if (!dentry) {
922 ret = -ENOMEM;
923 goto failed_dentry;
924 }
925 } else {
926 iput(inode);
927 }
928 } else {
929 dentry = d_obtain_root(inode);
930 if (IS_ERR(dentry)) {
931 ret = PTR_ERR(dentry);
932 goto failed_dentry;
933 }
934 }
935 *root_dentry = dentry;
936 out:
937 return ret;
938
939 failed_dentry:
940 nilfs_err(sb, "error %d getting root dentry", ret);
941 goto out;
942 }
943
nilfs_attach_snapshot(struct super_block * s,__u64 cno,struct dentry ** root_dentry)944 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
945 struct dentry **root_dentry)
946 {
947 struct the_nilfs *nilfs = s->s_fs_info;
948 struct nilfs_root *root;
949 int ret;
950
951 mutex_lock(&nilfs->ns_snapshot_mount_mutex);
952
953 down_read(&nilfs->ns_segctor_sem);
954 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
955 up_read(&nilfs->ns_segctor_sem);
956 if (ret < 0) {
957 ret = (ret == -ENOENT) ? -EINVAL : ret;
958 goto out;
959 } else if (!ret) {
960 nilfs_err(s,
961 "The specified checkpoint is not a snapshot (checkpoint number=%llu)",
962 (unsigned long long)cno);
963 ret = -EINVAL;
964 goto out;
965 }
966
967 ret = nilfs_attach_checkpoint(s, cno, false, &root);
968 if (ret) {
969 nilfs_err(s,
970 "error %d while loading snapshot (checkpoint number=%llu)",
971 ret, (unsigned long long)cno);
972 goto out;
973 }
974 ret = nilfs_get_root_dentry(s, root, root_dentry);
975 nilfs_put_root(root);
976 out:
977 mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
978 return ret;
979 }
980
981 /**
982 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
983 * @root_dentry: root dentry of the tree to be shrunk
984 *
985 * This function returns true if the tree was in-use.
986 */
nilfs_tree_is_busy(struct dentry * root_dentry)987 static bool nilfs_tree_is_busy(struct dentry *root_dentry)
988 {
989 shrink_dcache_parent(root_dentry);
990 return d_count(root_dentry) > 1;
991 }
992
nilfs_checkpoint_is_mounted(struct super_block * sb,__u64 cno)993 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
994 {
995 struct the_nilfs *nilfs = sb->s_fs_info;
996 struct nilfs_root *root;
997 struct inode *inode;
998 struct dentry *dentry;
999 int ret;
1000
1001 if (cno > nilfs->ns_cno)
1002 return false;
1003
1004 if (cno >= nilfs_last_cno(nilfs))
1005 return true; /* protect recent checkpoints */
1006
1007 ret = false;
1008 root = nilfs_lookup_root(nilfs, cno);
1009 if (root) {
1010 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
1011 if (inode) {
1012 dentry = d_find_alias(inode);
1013 if (dentry) {
1014 ret = nilfs_tree_is_busy(dentry);
1015 dput(dentry);
1016 }
1017 iput(inode);
1018 }
1019 nilfs_put_root(root);
1020 }
1021 return ret;
1022 }
1023
1024 /**
1025 * nilfs_fill_super() - initialize a super block instance
1026 * @sb: super_block
1027 * @data: mount options
1028 * @silent: silent mode flag
1029 *
1030 * This function is called exclusively by nilfs->ns_mount_mutex.
1031 * So, the recovery process is protected from other simultaneous mounts.
1032 */
1033 static int
nilfs_fill_super(struct super_block * sb,void * data,int silent)1034 nilfs_fill_super(struct super_block *sb, void *data, int silent)
1035 {
1036 struct the_nilfs *nilfs;
1037 struct nilfs_root *fsroot;
1038 __u64 cno;
1039 int err;
1040
1041 nilfs = alloc_nilfs(sb);
1042 if (!nilfs)
1043 return -ENOMEM;
1044
1045 sb->s_fs_info = nilfs;
1046
1047 err = init_nilfs(nilfs, sb, (char *)data);
1048 if (err)
1049 goto failed_nilfs;
1050
1051 sb->s_op = &nilfs_sops;
1052 sb->s_export_op = &nilfs_export_ops;
1053 sb->s_root = NULL;
1054 sb->s_time_gran = 1;
1055 sb->s_max_links = NILFS_LINK_MAX;
1056
1057 sb->s_bdi = bdi_get(sb->s_bdev->bd_bdi);
1058
1059 err = load_nilfs(nilfs, sb);
1060 if (err)
1061 goto failed_nilfs;
1062
1063 cno = nilfs_last_cno(nilfs);
1064 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
1065 if (err) {
1066 nilfs_err(sb,
1067 "error %d while loading last checkpoint (checkpoint number=%llu)",
1068 err, (unsigned long long)cno);
1069 goto failed_unload;
1070 }
1071
1072 if (!sb_rdonly(sb)) {
1073 err = nilfs_attach_log_writer(sb, fsroot);
1074 if (err)
1075 goto failed_checkpoint;
1076 }
1077
1078 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
1079 if (err)
1080 goto failed_segctor;
1081
1082 nilfs_put_root(fsroot);
1083
1084 if (!sb_rdonly(sb)) {
1085 down_write(&nilfs->ns_sem);
1086 nilfs_setup_super(sb, true);
1087 up_write(&nilfs->ns_sem);
1088 }
1089
1090 return 0;
1091
1092 failed_segctor:
1093 nilfs_detach_log_writer(sb);
1094
1095 failed_checkpoint:
1096 nilfs_put_root(fsroot);
1097
1098 failed_unload:
1099 iput(nilfs->ns_sufile);
1100 iput(nilfs->ns_cpfile);
1101 iput(nilfs->ns_dat);
1102
1103 failed_nilfs:
1104 destroy_nilfs(nilfs);
1105 return err;
1106 }
1107
nilfs_remount(struct super_block * sb,int * flags,char * data)1108 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
1109 {
1110 struct the_nilfs *nilfs = sb->s_fs_info;
1111 unsigned long old_sb_flags;
1112 unsigned long old_mount_opt;
1113 int err;
1114
1115 sync_filesystem(sb);
1116 old_sb_flags = sb->s_flags;
1117 old_mount_opt = nilfs->ns_mount_opt;
1118
1119 if (!parse_options(data, sb, 1)) {
1120 err = -EINVAL;
1121 goto restore_opts;
1122 }
1123 sb->s_flags = (sb->s_flags & ~SB_POSIXACL);
1124
1125 err = -EINVAL;
1126
1127 if (!nilfs_valid_fs(nilfs)) {
1128 nilfs_warn(sb,
1129 "couldn't remount because the filesystem is in an incomplete recovery state");
1130 goto restore_opts;
1131 }
1132
1133 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1134 goto out;
1135 if (*flags & SB_RDONLY) {
1136 sb->s_flags |= SB_RDONLY;
1137
1138 /*
1139 * Remounting a valid RW partition RDONLY, so set
1140 * the RDONLY flag and then mark the partition as valid again.
1141 */
1142 down_write(&nilfs->ns_sem);
1143 nilfs_cleanup_super(sb);
1144 up_write(&nilfs->ns_sem);
1145 } else {
1146 __u64 features;
1147 struct nilfs_root *root;
1148
1149 /*
1150 * Mounting a RDONLY partition read-write, so reread and
1151 * store the current valid flag. (It may have been changed
1152 * by fsck since we originally mounted the partition.)
1153 */
1154 down_read(&nilfs->ns_sem);
1155 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1156 ~NILFS_FEATURE_COMPAT_RO_SUPP;
1157 up_read(&nilfs->ns_sem);
1158 if (features) {
1159 nilfs_warn(sb,
1160 "couldn't remount RDWR because of unsupported optional features (%llx)",
1161 (unsigned long long)features);
1162 err = -EROFS;
1163 goto restore_opts;
1164 }
1165
1166 sb->s_flags &= ~SB_RDONLY;
1167
1168 root = NILFS_I(d_inode(sb->s_root))->i_root;
1169 err = nilfs_attach_log_writer(sb, root);
1170 if (err)
1171 goto restore_opts;
1172
1173 down_write(&nilfs->ns_sem);
1174 nilfs_setup_super(sb, true);
1175 up_write(&nilfs->ns_sem);
1176 }
1177 out:
1178 return 0;
1179
1180 restore_opts:
1181 sb->s_flags = old_sb_flags;
1182 nilfs->ns_mount_opt = old_mount_opt;
1183 return err;
1184 }
1185
1186 struct nilfs_super_data {
1187 struct block_device *bdev;
1188 __u64 cno;
1189 int flags;
1190 };
1191
nilfs_parse_snapshot_option(const char * option,const substring_t * arg,struct nilfs_super_data * sd)1192 static int nilfs_parse_snapshot_option(const char *option,
1193 const substring_t *arg,
1194 struct nilfs_super_data *sd)
1195 {
1196 unsigned long long val;
1197 const char *msg = NULL;
1198 int err;
1199
1200 if (!(sd->flags & SB_RDONLY)) {
1201 msg = "read-only option is not specified";
1202 goto parse_error;
1203 }
1204
1205 err = kstrtoull(arg->from, 0, &val);
1206 if (err) {
1207 if (err == -ERANGE)
1208 msg = "too large checkpoint number";
1209 else
1210 msg = "malformed argument";
1211 goto parse_error;
1212 } else if (val == 0) {
1213 msg = "invalid checkpoint number 0";
1214 goto parse_error;
1215 }
1216 sd->cno = val;
1217 return 0;
1218
1219 parse_error:
1220 nilfs_err(NULL, "invalid option \"%s\": %s", option, msg);
1221 return 1;
1222 }
1223
1224 /**
1225 * nilfs_identify - pre-read mount options needed to identify mount instance
1226 * @data: mount options
1227 * @sd: nilfs_super_data
1228 */
nilfs_identify(char * data,struct nilfs_super_data * sd)1229 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1230 {
1231 char *p, *options = data;
1232 substring_t args[MAX_OPT_ARGS];
1233 int token;
1234 int ret = 0;
1235
1236 do {
1237 p = strsep(&options, ",");
1238 if (p != NULL && *p) {
1239 token = match_token(p, tokens, args);
1240 if (token == Opt_snapshot)
1241 ret = nilfs_parse_snapshot_option(p, &args[0],
1242 sd);
1243 }
1244 if (!options)
1245 break;
1246 BUG_ON(options == data);
1247 *(options - 1) = ',';
1248 } while (!ret);
1249 return ret;
1250 }
1251
nilfs_set_bdev_super(struct super_block * s,void * data)1252 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1253 {
1254 s->s_bdev = data;
1255 s->s_dev = s->s_bdev->bd_dev;
1256 return 0;
1257 }
1258
nilfs_test_bdev_super(struct super_block * s,void * data)1259 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1260 {
1261 return (void *)s->s_bdev == data;
1262 }
1263
1264 static struct dentry *
nilfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1265 nilfs_mount(struct file_system_type *fs_type, int flags,
1266 const char *dev_name, void *data)
1267 {
1268 struct nilfs_super_data sd;
1269 struct super_block *s;
1270 fmode_t mode = FMODE_READ | FMODE_EXCL;
1271 struct dentry *root_dentry;
1272 int err, s_new = false;
1273
1274 if (!(flags & SB_RDONLY))
1275 mode |= FMODE_WRITE;
1276
1277 sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1278 if (IS_ERR(sd.bdev))
1279 return ERR_CAST(sd.bdev);
1280
1281 sd.cno = 0;
1282 sd.flags = flags;
1283 if (nilfs_identify((char *)data, &sd)) {
1284 err = -EINVAL;
1285 goto failed;
1286 }
1287
1288 /*
1289 * once the super is inserted into the list by sget, s_umount
1290 * will protect the lockfs code from trying to start a snapshot
1291 * while we are mounting
1292 */
1293 mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1294 if (sd.bdev->bd_fsfreeze_count > 0) {
1295 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1296 err = -EBUSY;
1297 goto failed;
1298 }
1299 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
1300 sd.bdev);
1301 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1302 if (IS_ERR(s)) {
1303 err = PTR_ERR(s);
1304 goto failed;
1305 }
1306
1307 if (!s->s_root) {
1308 s_new = true;
1309
1310 /* New superblock instance created */
1311 s->s_mode = mode;
1312 snprintf(s->s_id, sizeof(s->s_id), "%pg", sd.bdev);
1313 sb_set_blocksize(s, block_size(sd.bdev));
1314
1315 err = nilfs_fill_super(s, data, flags & SB_SILENT ? 1 : 0);
1316 if (err)
1317 goto failed_super;
1318
1319 s->s_flags |= SB_ACTIVE;
1320 } else if (!sd.cno) {
1321 if (nilfs_tree_is_busy(s->s_root)) {
1322 if ((flags ^ s->s_flags) & SB_RDONLY) {
1323 nilfs_err(s,
1324 "the device already has a %s mount.",
1325 sb_rdonly(s) ? "read-only" : "read/write");
1326 err = -EBUSY;
1327 goto failed_super;
1328 }
1329 } else {
1330 /*
1331 * Try remount to setup mount states if the current
1332 * tree is not mounted and only snapshots use this sb.
1333 */
1334 err = nilfs_remount(s, &flags, data);
1335 if (err)
1336 goto failed_super;
1337 }
1338 }
1339
1340 if (sd.cno) {
1341 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1342 if (err)
1343 goto failed_super;
1344 } else {
1345 root_dentry = dget(s->s_root);
1346 }
1347
1348 if (!s_new)
1349 blkdev_put(sd.bdev, mode);
1350
1351 return root_dentry;
1352
1353 failed_super:
1354 deactivate_locked_super(s);
1355
1356 failed:
1357 if (!s_new)
1358 blkdev_put(sd.bdev, mode);
1359 return ERR_PTR(err);
1360 }
1361
1362 struct file_system_type nilfs_fs_type = {
1363 .owner = THIS_MODULE,
1364 .name = "nilfs2",
1365 .mount = nilfs_mount,
1366 .kill_sb = kill_block_super,
1367 .fs_flags = FS_REQUIRES_DEV,
1368 };
1369 MODULE_ALIAS_FS("nilfs2");
1370
nilfs_inode_init_once(void * obj)1371 static void nilfs_inode_init_once(void *obj)
1372 {
1373 struct nilfs_inode_info *ii = obj;
1374
1375 INIT_LIST_HEAD(&ii->i_dirty);
1376 #ifdef CONFIG_NILFS_XATTR
1377 init_rwsem(&ii->xattr_sem);
1378 #endif
1379 inode_init_once(&ii->vfs_inode);
1380 }
1381
nilfs_segbuf_init_once(void * obj)1382 static void nilfs_segbuf_init_once(void *obj)
1383 {
1384 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1385 }
1386
nilfs_destroy_cachep(void)1387 static void nilfs_destroy_cachep(void)
1388 {
1389 /*
1390 * Make sure all delayed rcu free inodes are flushed before we
1391 * destroy cache.
1392 */
1393 rcu_barrier();
1394
1395 kmem_cache_destroy(nilfs_inode_cachep);
1396 kmem_cache_destroy(nilfs_transaction_cachep);
1397 kmem_cache_destroy(nilfs_segbuf_cachep);
1398 kmem_cache_destroy(nilfs_btree_path_cache);
1399 }
1400
nilfs_init_cachep(void)1401 static int __init nilfs_init_cachep(void)
1402 {
1403 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1404 sizeof(struct nilfs_inode_info), 0,
1405 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
1406 nilfs_inode_init_once);
1407 if (!nilfs_inode_cachep)
1408 goto fail;
1409
1410 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1411 sizeof(struct nilfs_transaction_info), 0,
1412 SLAB_RECLAIM_ACCOUNT, NULL);
1413 if (!nilfs_transaction_cachep)
1414 goto fail;
1415
1416 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1417 sizeof(struct nilfs_segment_buffer), 0,
1418 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1419 if (!nilfs_segbuf_cachep)
1420 goto fail;
1421
1422 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1423 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1424 0, 0, NULL);
1425 if (!nilfs_btree_path_cache)
1426 goto fail;
1427
1428 return 0;
1429
1430 fail:
1431 nilfs_destroy_cachep();
1432 return -ENOMEM;
1433 }
1434
init_nilfs_fs(void)1435 static int __init init_nilfs_fs(void)
1436 {
1437 int err;
1438
1439 err = nilfs_init_cachep();
1440 if (err)
1441 goto fail;
1442
1443 err = nilfs_sysfs_init();
1444 if (err)
1445 goto free_cachep;
1446
1447 err = register_filesystem(&nilfs_fs_type);
1448 if (err)
1449 goto deinit_sysfs_entry;
1450
1451 printk(KERN_INFO "NILFS version 2 loaded\n");
1452 return 0;
1453
1454 deinit_sysfs_entry:
1455 nilfs_sysfs_exit();
1456 free_cachep:
1457 nilfs_destroy_cachep();
1458 fail:
1459 return err;
1460 }
1461
exit_nilfs_fs(void)1462 static void __exit exit_nilfs_fs(void)
1463 {
1464 nilfs_destroy_cachep();
1465 nilfs_sysfs_exit();
1466 unregister_filesystem(&nilfs_fs_type);
1467 }
1468
1469 module_init(init_nilfs_fs)
1470 module_exit(exit_nilfs_fs)
1471