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 MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
57
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;
62
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);
65
__nilfs_msg(struct super_block * sb,const char * fmt,...)66 void __nilfs_msg(struct super_block *sb, const char *fmt, ...)
67 {
68 struct va_format vaf;
69 va_list args;
70 int level;
71
72 va_start(args, fmt);
73
74 level = printk_get_level(fmt);
75 vaf.fmt = printk_skip_level(fmt);
76 vaf.va = &args;
77
78 if (sb)
79 printk("%c%cNILFS (%s): %pV\n",
80 KERN_SOH_ASCII, level, sb->s_id, &vaf);
81 else
82 printk("%c%cNILFS: %pV\n",
83 KERN_SOH_ASCII, level, &vaf);
84
85 va_end(args);
86 }
87
nilfs_set_error(struct super_block * sb)88 static void nilfs_set_error(struct super_block *sb)
89 {
90 struct the_nilfs *nilfs = sb->s_fs_info;
91 struct nilfs_super_block **sbp;
92
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);
97 if (likely(sbp)) {
98 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
99 if (sbp[1])
100 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
101 nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
102 }
103 }
104 up_write(&nilfs->ns_sem);
105 }
106
107 /**
108 * __nilfs_error() - report failure condition on a filesystem
109 *
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.
113 *
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.
117 *
118 * Callers should not add a trailing newline since this will do it.
119 */
__nilfs_error(struct super_block * sb,const char * function,const char * fmt,...)120 void __nilfs_error(struct super_block *sb, const char *function,
121 const char *fmt, ...)
122 {
123 struct the_nilfs *nilfs = sb->s_fs_info;
124 struct va_format vaf;
125 va_list args;
126
127 va_start(args, fmt);
128
129 vaf.fmt = fmt;
130 vaf.va = &args;
131
132 printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
133 sb->s_id, function, &vaf);
134
135 va_end(args);
136
137 if (!sb_rdonly(sb)) {
138 nilfs_set_error(sb);
139
140 if (nilfs_test_opt(nilfs, ERRORS_RO)) {
141 printk(KERN_CRIT "Remounting filesystem read-only\n");
142 sb->s_flags |= SB_RDONLY;
143 }
144 }
145
146 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
147 panic("NILFS (device %s): panic forced after error\n",
148 sb->s_id);
149 }
150
nilfs_alloc_inode(struct super_block * sb)151 struct inode *nilfs_alloc_inode(struct super_block *sb)
152 {
153 struct nilfs_inode_info *ii;
154
155 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
156 if (!ii)
157 return NULL;
158 ii->i_bh = NULL;
159 ii->i_state = 0;
160 ii->i_cno = 0;
161 ii->i_assoc_inode = NULL;
162 ii->i_bmap = &ii->i_bmap_data;
163 return &ii->vfs_inode;
164 }
165
nilfs_free_inode(struct inode * inode)166 static void nilfs_free_inode(struct inode *inode)
167 {
168 if (nilfs_is_metadata_file_inode(inode))
169 nilfs_mdt_destroy(inode);
170
171 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
172 }
173
nilfs_sync_super(struct super_block * sb,int flag)174 static int nilfs_sync_super(struct super_block *sb, int flag)
175 {
176 struct the_nilfs *nilfs = sb->s_fs_info;
177 int err;
178
179 retry:
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);
184 } else {
185 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
186 }
187
188 if (unlikely(err)) {
189 nilfs_err(sb, "unable to write superblock: err=%d", err);
190 if (err == -EIO && nilfs->ns_sbh[1]) {
191 /*
192 * sbp[0] points to newer log than sbp[1],
193 * so copy sbp[0] to sbp[1] to take over sbp[0].
194 */
195 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
196 nilfs->ns_sbsize);
197 nilfs_fall_back_super_block(nilfs);
198 goto retry;
199 }
200 } else {
201 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
202
203 nilfs->ns_sbwcount++;
204
205 /*
206 * The latest segment becomes trailable from the position
207 * written in superblock.
208 */
209 clear_nilfs_discontinued(nilfs);
210
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)
216 goto out;
217 }
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];
221 }
222
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);
226 }
227 out:
228 return err;
229 }
230
nilfs_set_log_cursor(struct nilfs_super_block * sbp,struct the_nilfs * nilfs)231 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
232 struct the_nilfs *nilfs)
233 {
234 sector_t nfreeblocks;
235
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);
239
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);
245 }
246
nilfs_prepare_super(struct super_block * sb,int flip)247 struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
248 int flip)
249 {
250 struct the_nilfs *nilfs = sb->s_fs_info;
251 struct nilfs_super_block **sbp = nilfs->ns_sbp;
252
253 /* nilfs->ns_sem must be locked by the caller. */
254 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
255 if (sbp[1] &&
256 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
257 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
258 } else {
259 nilfs_crit(sb, "superblock broke");
260 return NULL;
261 }
262 } else if (sbp[1] &&
263 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
264 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
265 }
266
267 if (flip && sbp[1])
268 nilfs_swap_super_block(nilfs);
269
270 return sbp;
271 }
272
nilfs_commit_super(struct super_block * sb,int flag)273 int nilfs_commit_super(struct super_block *sb, int flag)
274 {
275 struct the_nilfs *nilfs = sb->s_fs_info;
276 struct nilfs_super_block **sbp = nilfs->ns_sbp;
277 time64_t t;
278
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);
283 sbp[0]->s_sum = 0;
284 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
285 (unsigned char *)sbp[0],
286 nilfs->ns_sbsize));
287 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
288 sbp[1]->s_wtime = sbp[0]->s_wtime;
289 sbp[1]->s_sum = 0;
290 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
291 (unsigned char *)sbp[1],
292 nilfs->ns_sbsize));
293 }
294 clear_nilfs_sb_dirty(nilfs);
295 nilfs->ns_flushed_device = 1;
296 /* make sure store to ns_flushed_device cannot be reordered */
297 smp_wmb();
298 return nilfs_sync_super(sb, flag);
299 }
300
301 /**
302 * nilfs_cleanup_super() - write filesystem state for cleanup
303 * @sb: super block instance to be unmounted or degraded to read-only
304 *
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.
308 */
nilfs_cleanup_super(struct super_block * sb)309 int nilfs_cleanup_super(struct super_block *sb)
310 {
311 struct the_nilfs *nilfs = sb->s_fs_info;
312 struct nilfs_super_block **sbp;
313 int flag = NILFS_SB_COMMIT;
314 int ret = -EIO;
315
316 sbp = nilfs_prepare_super(sb, 0);
317 if (sbp) {
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) {
321 /*
322 * make the "clean" flag also to the opposite
323 * super block if both super blocks point to
324 * the same checkpoint.
325 */
326 sbp[1]->s_state = sbp[0]->s_state;
327 flag = NILFS_SB_COMMIT_ALL;
328 }
329 ret = nilfs_commit_super(sb, flag);
330 }
331 return ret;
332 }
333
334 /**
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)
338 */
nilfs_move_2nd_super(struct super_block * sb,loff_t sb2off)339 static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
340 {
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 */
347 int ret = 0;
348
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) {
352 sb2i = 1;
353 blocknr = nilfs->ns_sbh[1]->b_blocknr;
354 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
355 sb2i = 0;
356 blocknr = nilfs->ns_sbh[0]->b_blocknr;
357 } else {
358 sb2i = -1;
359 blocknr = 0;
360 }
361 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
362 goto out; /* super block location is unchanged */
363
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);
368 if (!nsbh) {
369 nilfs_warn(sb,
370 "unable to move secondary superblock to block %llu",
371 (unsigned long long)newblocknr);
372 ret = -EIO;
373 goto out;
374 }
375 nsbp = (void *)nsbh->b_data + offset;
376
377 lock_buffer(nsbh);
378 if (sb2i >= 0) {
379 /*
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.
384 */
385 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
386
387 /*
388 * Zero fill after copy to avoid overwriting in case of move
389 * within the same block.
390 */
391 memset(nsbh->b_data, 0, offset);
392 memset((void *)nsbp + nilfs->ns_sbsize, 0,
393 nsbh->b_size - offset - nilfs->ns_sbsize);
394 } else {
395 memset(nsbh->b_data, 0, nsbh->b_size);
396 }
397 set_buffer_uptodate(nsbh);
398 unlock_buffer(nsbh);
399
400 if (sb2i >= 0) {
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;
408 } else {
409 brelse(nsbh);
410 }
411 out:
412 return ret;
413 }
414
415 /**
416 * nilfs_resize_fs - resize the filesystem
417 * @sb: super block instance
418 * @newsize: new size of the filesystem (in bytes)
419 */
nilfs_resize_fs(struct super_block * sb,__u64 newsize)420 int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
421 {
422 struct the_nilfs *nilfs = sb->s_fs_info;
423 struct nilfs_super_block **sbp;
424 __u64 devsize, newnsegs;
425 loff_t sb2off;
426 int ret;
427
428 ret = -ERANGE;
429 devsize = i_size_read(sb->s_bdev->bd_inode);
430 if (newsize > devsize)
431 goto out;
432
433 /*
434 * Prevent underflow in second superblock position calculation.
435 * The exact minimum size check is done in nilfs_sufile_resize().
436 */
437 if (newsize < 4096) {
438 ret = -ENOSPC;
439 goto out;
440 }
441
442 /*
443 * Write lock is required to protect some functions depending
444 * on the number of segments, the number of reserved segments,
445 * and so forth.
446 */
447 down_write(&nilfs->ns_segctor_sem);
448
449 sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
450 newnsegs = sb2off >> nilfs->ns_blocksize_bits;
451 do_div(newnsegs, nilfs->ns_blocks_per_segment);
452
453 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
454 up_write(&nilfs->ns_segctor_sem);
455 if (ret < 0)
456 goto out;
457
458 ret = nilfs_construct_segment(sb);
459 if (ret < 0)
460 goto out;
461
462 down_write(&nilfs->ns_sem);
463 nilfs_move_2nd_super(sb, sb2off);
464 ret = -EIO;
465 sbp = nilfs_prepare_super(sb, 0);
466 if (likely(sbp)) {
467 nilfs_set_log_cursor(sbp[0], nilfs);
468 /*
469 * Drop NILFS_RESIZE_FS flag for compatibility with
470 * mount-time resize which may be implemented in a
471 * future release.
472 */
473 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
474 ~NILFS_RESIZE_FS);
475 sbp[0]->s_dev_size = cpu_to_le64(newsize);
476 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
477 if (sbp[1])
478 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
479 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
480 }
481 up_write(&nilfs->ns_sem);
482
483 /*
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
487 * completes.
488 */
489 if (!ret)
490 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
491 out:
492 return ret;
493 }
494
nilfs_put_super(struct super_block * sb)495 static void nilfs_put_super(struct super_block *sb)
496 {
497 struct the_nilfs *nilfs = sb->s_fs_info;
498
499 nilfs_detach_log_writer(sb);
500
501 if (!sb_rdonly(sb)) {
502 down_write(&nilfs->ns_sem);
503 nilfs_cleanup_super(sb);
504 up_write(&nilfs->ns_sem);
505 }
506
507 nilfs_sysfs_delete_device_group(nilfs);
508 iput(nilfs->ns_sufile);
509 iput(nilfs->ns_cpfile);
510 iput(nilfs->ns_dat);
511
512 destroy_nilfs(nilfs);
513 sb->s_fs_info = NULL;
514 }
515
nilfs_sync_fs(struct super_block * sb,int wait)516 static int nilfs_sync_fs(struct super_block *sb, int wait)
517 {
518 struct the_nilfs *nilfs = sb->s_fs_info;
519 struct nilfs_super_block **sbp;
520 int err = 0;
521
522 /* This function is called when super block should be written back */
523 if (wait)
524 err = nilfs_construct_segment(sb);
525
526 down_write(&nilfs->ns_sem);
527 if (nilfs_sb_dirty(nilfs)) {
528 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
529 if (likely(sbp)) {
530 nilfs_set_log_cursor(sbp[0], nilfs);
531 nilfs_commit_super(sb, NILFS_SB_COMMIT);
532 }
533 }
534 up_write(&nilfs->ns_sem);
535
536 if (!err)
537 err = nilfs_flush_device(nilfs);
538
539 return err;
540 }
541
nilfs_attach_checkpoint(struct super_block * sb,__u64 cno,int curr_mnt,struct nilfs_root ** rootp)542 int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
543 struct nilfs_root **rootp)
544 {
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;
549 int err = -ENOMEM;
550
551 root = nilfs_find_or_create_root(
552 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
553 if (!root)
554 return err;
555
556 if (root->ifile)
557 goto reuse; /* already attached checkpoint */
558
559 down_read(&nilfs->ns_segctor_sem);
560 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
561 &bh_cp);
562 up_read(&nilfs->ns_segctor_sem);
563 if (unlikely(err)) {
564 if (err == -ENOENT || err == -EINVAL) {
565 nilfs_err(sb,
566 "Invalid checkpoint (checkpoint number=%llu)",
567 (unsigned long long)cno);
568 err = -EINVAL;
569 }
570 goto failed;
571 }
572
573 err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
574 &raw_cp->cp_ifile_inode, &root->ifile);
575 if (err)
576 goto failed_bh;
577
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));
582
583 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
584
585 reuse:
586 *rootp = root;
587 return 0;
588
589 failed_bh:
590 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
591 failed:
592 nilfs_put_root(root);
593
594 return err;
595 }
596
nilfs_freeze(struct super_block * sb)597 static int nilfs_freeze(struct super_block *sb)
598 {
599 struct the_nilfs *nilfs = sb->s_fs_info;
600 int err;
601
602 if (sb_rdonly(sb))
603 return 0;
604
605 /* Mark super block clean */
606 down_write(&nilfs->ns_sem);
607 err = nilfs_cleanup_super(sb);
608 up_write(&nilfs->ns_sem);
609 return err;
610 }
611
nilfs_unfreeze(struct super_block * sb)612 static int nilfs_unfreeze(struct super_block *sb)
613 {
614 struct the_nilfs *nilfs = sb->s_fs_info;
615
616 if (sb_rdonly(sb))
617 return 0;
618
619 down_write(&nilfs->ns_sem);
620 nilfs_setup_super(sb, false);
621 up_write(&nilfs->ns_sem);
622 return 0;
623 }
624
nilfs_statfs(struct dentry * dentry,struct kstatfs * buf)625 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
626 {
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;
636 int err;
637
638 /*
639 * Compute all of the segment blocks
640 *
641 * The blocks before first segment and after last segment
642 * are excluded.
643 */
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;
647
648 /*
649 * Compute the overhead
650 *
651 * When distributing meta data blocks outside segment structure,
652 * We must count them as the overhead.
653 */
654 overhead = 0;
655
656 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
657 if (unlikely(err))
658 return err;
659
660 err = nilfs_ifile_count_free_inodes(root->ifile,
661 &nmaxinodes, &nfreeinodes);
662 if (unlikely(err)) {
663 nilfs_warn(sb, "failed to count free inodes: err=%d", err);
664 if (err == -ERANGE) {
665 /*
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.
670 */
671 nmaxinodes = atomic64_read(&root->inodes_count);
672 nfreeinodes = 0;
673 err = 0;
674 } else
675 return err;
676 }
677
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);
688
689 return 0;
690 }
691
nilfs_show_options(struct seq_file * seq,struct dentry * dentry)692 static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
693 {
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;
697
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");
712
713 return 0;
714 }
715
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
728 };
729
730 enum {
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,
734 };
735
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"},
747 {Opt_err, NULL}
748 };
749
parse_options(char * options,struct super_block * sb,int is_remount)750 static int parse_options(char *options, struct super_block *sb, int is_remount)
751 {
752 struct the_nilfs *nilfs = sb->s_fs_info;
753 char *p;
754 substring_t args[MAX_OPT_ARGS];
755
756 if (!options)
757 return 1;
758
759 while ((p = strsep(&options, ",")) != NULL) {
760 int token;
761
762 if (!*p)
763 continue;
764
765 token = match_token(p, tokens, args);
766 switch (token) {
767 case Opt_barrier:
768 nilfs_set_opt(nilfs, BARRIER);
769 break;
770 case Opt_nobarrier:
771 nilfs_clear_opt(nilfs, BARRIER);
772 break;
773 case Opt_order:
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);
780 else
781 return 0;
782 break;
783 case Opt_err_panic:
784 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
785 break;
786 case Opt_err_ro:
787 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
788 break;
789 case Opt_err_cont:
790 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
791 break;
792 case Opt_snapshot:
793 if (is_remount) {
794 nilfs_err(sb,
795 "\"%s\" option is invalid for remount",
796 p);
797 return 0;
798 }
799 break;
800 case Opt_norecovery:
801 nilfs_set_opt(nilfs, NORECOVERY);
802 break;
803 case Opt_discard:
804 nilfs_set_opt(nilfs, DISCARD);
805 break;
806 case Opt_nodiscard:
807 nilfs_clear_opt(nilfs, DISCARD);
808 break;
809 default:
810 nilfs_err(sb, "unrecognized mount option \"%s\"", p);
811 return 0;
812 }
813 }
814 return 1;
815 }
816
817 static inline void
nilfs_set_default_options(struct super_block * sb,struct nilfs_super_block * sbp)818 nilfs_set_default_options(struct super_block *sb,
819 struct nilfs_super_block *sbp)
820 {
821 struct the_nilfs *nilfs = sb->s_fs_info;
822
823 nilfs->ns_mount_opt =
824 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
825 }
826
nilfs_setup_super(struct super_block * sb,int is_mount)827 static int nilfs_setup_super(struct super_block *sb, int is_mount)
828 {
829 struct the_nilfs *nilfs = sb->s_fs_info;
830 struct nilfs_super_block **sbp;
831 int max_mnt_count;
832 int mnt_count;
833
834 /* nilfs->ns_sem must be locked by the caller. */
835 sbp = nilfs_prepare_super(sb, 0);
836 if (!sbp)
837 return -EIO;
838
839 if (!is_mount)
840 goto skip_mount_setup;
841
842 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
843 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
844
845 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
846 nilfs_warn(sb, "mounting fs with errors");
847 #if 0
848 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
849 nilfs_warn(sb, "maximal mount count reached");
850 #endif
851 }
852 if (!max_mnt_count)
853 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
854
855 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
856 sbp[0]->s_mtime = cpu_to_le64(ktime_get_real_seconds());
857
858 skip_mount_setup:
859 sbp[0]->s_state =
860 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
861 /* synchronize sbp[1] with sbp[0] */
862 if (sbp[1])
863 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
864 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
865 }
866
nilfs_read_super_block(struct super_block * sb,u64 pos,int blocksize,struct buffer_head ** pbh)867 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
868 u64 pos, int blocksize,
869 struct buffer_head **pbh)
870 {
871 unsigned long long sb_index = pos;
872 unsigned long offset;
873
874 offset = do_div(sb_index, blocksize);
875 *pbh = sb_bread(sb, sb_index);
876 if (!*pbh)
877 return NULL;
878 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
879 }
880
nilfs_store_magic_and_option(struct super_block * sb,struct nilfs_super_block * sbp,char * data)881 int nilfs_store_magic_and_option(struct super_block *sb,
882 struct nilfs_super_block *sbp,
883 char *data)
884 {
885 struct the_nilfs *nilfs = sb->s_fs_info;
886
887 sb->s_magic = le16_to_cpu(sbp->s_magic);
888
889 /* FS independent flags */
890 #ifdef NILFS_ATIME_DISABLE
891 sb->s_flags |= SB_NOATIME;
892 #endif
893
894 nilfs_set_default_options(sb, sbp);
895
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);
900
901 return !parse_options(data, sb, 0) ? -EINVAL : 0;
902 }
903
nilfs_check_feature_compatibility(struct super_block * sb,struct nilfs_super_block * sbp)904 int nilfs_check_feature_compatibility(struct super_block *sb,
905 struct nilfs_super_block *sbp)
906 {
907 __u64 features;
908
909 features = le64_to_cpu(sbp->s_feature_incompat) &
910 ~NILFS_FEATURE_INCOMPAT_SUPP;
911 if (features) {
912 nilfs_err(sb,
913 "couldn't mount because of unsupported optional features (%llx)",
914 (unsigned long long)features);
915 return -EINVAL;
916 }
917 features = le64_to_cpu(sbp->s_feature_compat_ro) &
918 ~NILFS_FEATURE_COMPAT_RO_SUPP;
919 if (!sb_rdonly(sb) && features) {
920 nilfs_err(sb,
921 "couldn't mount RDWR because of unsupported optional features (%llx)",
922 (unsigned long long)features);
923 return -EINVAL;
924 }
925 return 0;
926 }
927
nilfs_get_root_dentry(struct super_block * sb,struct nilfs_root * root,struct dentry ** root_dentry)928 static int nilfs_get_root_dentry(struct super_block *sb,
929 struct nilfs_root *root,
930 struct dentry **root_dentry)
931 {
932 struct inode *inode;
933 struct dentry *dentry;
934 int ret = 0;
935
936 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
937 if (IS_ERR(inode)) {
938 ret = PTR_ERR(inode);
939 nilfs_err(sb, "error %d getting root inode", ret);
940 goto out;
941 }
942 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
943 iput(inode);
944 nilfs_err(sb, "corrupt root inode");
945 ret = -EINVAL;
946 goto out;
947 }
948
949 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
950 dentry = d_find_alias(inode);
951 if (!dentry) {
952 dentry = d_make_root(inode);
953 if (!dentry) {
954 ret = -ENOMEM;
955 goto failed_dentry;
956 }
957 } else {
958 iput(inode);
959 }
960 } else {
961 dentry = d_obtain_root(inode);
962 if (IS_ERR(dentry)) {
963 ret = PTR_ERR(dentry);
964 goto failed_dentry;
965 }
966 }
967 *root_dentry = dentry;
968 out:
969 return ret;
970
971 failed_dentry:
972 nilfs_err(sb, "error %d getting root dentry", ret);
973 goto out;
974 }
975
nilfs_attach_snapshot(struct super_block * s,__u64 cno,struct dentry ** root_dentry)976 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
977 struct dentry **root_dentry)
978 {
979 struct the_nilfs *nilfs = s->s_fs_info;
980 struct nilfs_root *root;
981 int ret;
982
983 mutex_lock(&nilfs->ns_snapshot_mount_mutex);
984
985 down_read(&nilfs->ns_segctor_sem);
986 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
987 up_read(&nilfs->ns_segctor_sem);
988 if (ret < 0) {
989 ret = (ret == -ENOENT) ? -EINVAL : ret;
990 goto out;
991 } else if (!ret) {
992 nilfs_err(s,
993 "The specified checkpoint is not a snapshot (checkpoint number=%llu)",
994 (unsigned long long)cno);
995 ret = -EINVAL;
996 goto out;
997 }
998
999 ret = nilfs_attach_checkpoint(s, cno, false, &root);
1000 if (ret) {
1001 nilfs_err(s,
1002 "error %d while loading snapshot (checkpoint number=%llu)",
1003 ret, (unsigned long long)cno);
1004 goto out;
1005 }
1006 ret = nilfs_get_root_dentry(s, root, root_dentry);
1007 nilfs_put_root(root);
1008 out:
1009 mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
1010 return ret;
1011 }
1012
1013 /**
1014 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
1015 * @root_dentry: root dentry of the tree to be shrunk
1016 *
1017 * This function returns true if the tree was in-use.
1018 */
nilfs_tree_is_busy(struct dentry * root_dentry)1019 static bool nilfs_tree_is_busy(struct dentry *root_dentry)
1020 {
1021 shrink_dcache_parent(root_dentry);
1022 return d_count(root_dentry) > 1;
1023 }
1024
nilfs_checkpoint_is_mounted(struct super_block * sb,__u64 cno)1025 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
1026 {
1027 struct the_nilfs *nilfs = sb->s_fs_info;
1028 struct nilfs_root *root;
1029 struct inode *inode;
1030 struct dentry *dentry;
1031 int ret;
1032
1033 if (cno > nilfs->ns_cno)
1034 return false;
1035
1036 if (cno >= nilfs_last_cno(nilfs))
1037 return true; /* protect recent checkpoints */
1038
1039 ret = false;
1040 root = nilfs_lookup_root(nilfs, cno);
1041 if (root) {
1042 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
1043 if (inode) {
1044 dentry = d_find_alias(inode);
1045 if (dentry) {
1046 ret = nilfs_tree_is_busy(dentry);
1047 dput(dentry);
1048 }
1049 iput(inode);
1050 }
1051 nilfs_put_root(root);
1052 }
1053 return ret;
1054 }
1055
1056 /**
1057 * nilfs_fill_super() - initialize a super block instance
1058 * @sb: super_block
1059 * @data: mount options
1060 * @silent: silent mode flag
1061 *
1062 * This function is called exclusively by nilfs->ns_mount_mutex.
1063 * So, the recovery process is protected from other simultaneous mounts.
1064 */
1065 static int
nilfs_fill_super(struct super_block * sb,void * data,int silent)1066 nilfs_fill_super(struct super_block *sb, void *data, int silent)
1067 {
1068 struct the_nilfs *nilfs;
1069 struct nilfs_root *fsroot;
1070 __u64 cno;
1071 int err;
1072
1073 nilfs = alloc_nilfs(sb);
1074 if (!nilfs)
1075 return -ENOMEM;
1076
1077 sb->s_fs_info = nilfs;
1078
1079 err = init_nilfs(nilfs, sb, (char *)data);
1080 if (err)
1081 goto failed_nilfs;
1082
1083 sb->s_op = &nilfs_sops;
1084 sb->s_export_op = &nilfs_export_ops;
1085 sb->s_root = NULL;
1086 sb->s_time_gran = 1;
1087 sb->s_max_links = NILFS_LINK_MAX;
1088
1089 sb->s_bdi = bdi_get(sb->s_bdev->bd_bdi);
1090
1091 err = load_nilfs(nilfs, sb);
1092 if (err)
1093 goto failed_nilfs;
1094
1095 cno = nilfs_last_cno(nilfs);
1096 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
1097 if (err) {
1098 nilfs_err(sb,
1099 "error %d while loading last checkpoint (checkpoint number=%llu)",
1100 err, (unsigned long long)cno);
1101 goto failed_unload;
1102 }
1103
1104 if (!sb_rdonly(sb)) {
1105 err = nilfs_attach_log_writer(sb, fsroot);
1106 if (err)
1107 goto failed_checkpoint;
1108 }
1109
1110 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
1111 if (err)
1112 goto failed_segctor;
1113
1114 nilfs_put_root(fsroot);
1115
1116 if (!sb_rdonly(sb)) {
1117 down_write(&nilfs->ns_sem);
1118 nilfs_setup_super(sb, true);
1119 up_write(&nilfs->ns_sem);
1120 }
1121
1122 return 0;
1123
1124 failed_segctor:
1125 nilfs_detach_log_writer(sb);
1126
1127 failed_checkpoint:
1128 nilfs_put_root(fsroot);
1129
1130 failed_unload:
1131 nilfs_sysfs_delete_device_group(nilfs);
1132 iput(nilfs->ns_sufile);
1133 iput(nilfs->ns_cpfile);
1134 iput(nilfs->ns_dat);
1135
1136 failed_nilfs:
1137 destroy_nilfs(nilfs);
1138 return err;
1139 }
1140
nilfs_remount(struct super_block * sb,int * flags,char * data)1141 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
1142 {
1143 struct the_nilfs *nilfs = sb->s_fs_info;
1144 unsigned long old_sb_flags;
1145 unsigned long old_mount_opt;
1146 int err;
1147
1148 sync_filesystem(sb);
1149 old_sb_flags = sb->s_flags;
1150 old_mount_opt = nilfs->ns_mount_opt;
1151
1152 if (!parse_options(data, sb, 1)) {
1153 err = -EINVAL;
1154 goto restore_opts;
1155 }
1156 sb->s_flags = (sb->s_flags & ~SB_POSIXACL);
1157
1158 err = -EINVAL;
1159
1160 if (!nilfs_valid_fs(nilfs)) {
1161 nilfs_warn(sb,
1162 "couldn't remount because the filesystem is in an incomplete recovery state");
1163 goto restore_opts;
1164 }
1165
1166 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1167 goto out;
1168 if (*flags & SB_RDONLY) {
1169 sb->s_flags |= SB_RDONLY;
1170
1171 /*
1172 * Remounting a valid RW partition RDONLY, so set
1173 * the RDONLY flag and then mark the partition as valid again.
1174 */
1175 down_write(&nilfs->ns_sem);
1176 nilfs_cleanup_super(sb);
1177 up_write(&nilfs->ns_sem);
1178 } else {
1179 __u64 features;
1180 struct nilfs_root *root;
1181
1182 /*
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.)
1186 */
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);
1191 if (features) {
1192 nilfs_warn(sb,
1193 "couldn't remount RDWR because of unsupported optional features (%llx)",
1194 (unsigned long long)features);
1195 err = -EROFS;
1196 goto restore_opts;
1197 }
1198
1199 sb->s_flags &= ~SB_RDONLY;
1200
1201 root = NILFS_I(d_inode(sb->s_root))->i_root;
1202 err = nilfs_attach_log_writer(sb, root);
1203 if (err)
1204 goto restore_opts;
1205
1206 down_write(&nilfs->ns_sem);
1207 nilfs_setup_super(sb, true);
1208 up_write(&nilfs->ns_sem);
1209 }
1210 out:
1211 return 0;
1212
1213 restore_opts:
1214 sb->s_flags = old_sb_flags;
1215 nilfs->ns_mount_opt = old_mount_opt;
1216 return err;
1217 }
1218
1219 struct nilfs_super_data {
1220 struct block_device *bdev;
1221 __u64 cno;
1222 int flags;
1223 };
1224
nilfs_parse_snapshot_option(const char * option,const substring_t * arg,struct nilfs_super_data * sd)1225 static int nilfs_parse_snapshot_option(const char *option,
1226 const substring_t *arg,
1227 struct nilfs_super_data *sd)
1228 {
1229 unsigned long long val;
1230 const char *msg = NULL;
1231 int err;
1232
1233 if (!(sd->flags & SB_RDONLY)) {
1234 msg = "read-only option is not specified";
1235 goto parse_error;
1236 }
1237
1238 err = kstrtoull(arg->from, 0, &val);
1239 if (err) {
1240 if (err == -ERANGE)
1241 msg = "too large checkpoint number";
1242 else
1243 msg = "malformed argument";
1244 goto parse_error;
1245 } else if (val == 0) {
1246 msg = "invalid checkpoint number 0";
1247 goto parse_error;
1248 }
1249 sd->cno = val;
1250 return 0;
1251
1252 parse_error:
1253 nilfs_err(NULL, "invalid option \"%s\": %s", option, msg);
1254 return 1;
1255 }
1256
1257 /**
1258 * nilfs_identify - pre-read mount options needed to identify mount instance
1259 * @data: mount options
1260 * @sd: nilfs_super_data
1261 */
nilfs_identify(char * data,struct nilfs_super_data * sd)1262 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1263 {
1264 char *p, *options = data;
1265 substring_t args[MAX_OPT_ARGS];
1266 int token;
1267 int ret = 0;
1268
1269 do {
1270 p = strsep(&options, ",");
1271 if (p != NULL && *p) {
1272 token = match_token(p, tokens, args);
1273 if (token == Opt_snapshot)
1274 ret = nilfs_parse_snapshot_option(p, &args[0],
1275 sd);
1276 }
1277 if (!options)
1278 break;
1279 BUG_ON(options == data);
1280 *(options - 1) = ',';
1281 } while (!ret);
1282 return ret;
1283 }
1284
nilfs_set_bdev_super(struct super_block * s,void * data)1285 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1286 {
1287 s->s_bdev = data;
1288 s->s_dev = s->s_bdev->bd_dev;
1289 return 0;
1290 }
1291
nilfs_test_bdev_super(struct super_block * s,void * data)1292 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1293 {
1294 return (void *)s->s_bdev == data;
1295 }
1296
1297 static struct dentry *
nilfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1298 nilfs_mount(struct file_system_type *fs_type, int flags,
1299 const char *dev_name, void *data)
1300 {
1301 struct nilfs_super_data sd;
1302 struct super_block *s;
1303 fmode_t mode = FMODE_READ | FMODE_EXCL;
1304 struct dentry *root_dentry;
1305 int err, s_new = false;
1306
1307 if (!(flags & SB_RDONLY))
1308 mode |= FMODE_WRITE;
1309
1310 sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1311 if (IS_ERR(sd.bdev))
1312 return ERR_CAST(sd.bdev);
1313
1314 sd.cno = 0;
1315 sd.flags = flags;
1316 if (nilfs_identify((char *)data, &sd)) {
1317 err = -EINVAL;
1318 goto failed;
1319 }
1320
1321 /*
1322 * once the super is inserted into the list by sget, s_umount
1323 * will protect the lockfs code from trying to start a snapshot
1324 * while we are mounting
1325 */
1326 mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1327 if (sd.bdev->bd_fsfreeze_count > 0) {
1328 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1329 err = -EBUSY;
1330 goto failed;
1331 }
1332 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
1333 sd.bdev);
1334 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1335 if (IS_ERR(s)) {
1336 err = PTR_ERR(s);
1337 goto failed;
1338 }
1339
1340 if (!s->s_root) {
1341 s_new = true;
1342
1343 /* New superblock instance created */
1344 s->s_mode = mode;
1345 snprintf(s->s_id, sizeof(s->s_id), "%pg", sd.bdev);
1346 sb_set_blocksize(s, block_size(sd.bdev));
1347
1348 err = nilfs_fill_super(s, data, flags & SB_SILENT ? 1 : 0);
1349 if (err)
1350 goto failed_super;
1351
1352 s->s_flags |= SB_ACTIVE;
1353 } else if (!sd.cno) {
1354 if (nilfs_tree_is_busy(s->s_root)) {
1355 if ((flags ^ s->s_flags) & SB_RDONLY) {
1356 nilfs_err(s,
1357 "the device already has a %s mount.",
1358 sb_rdonly(s) ? "read-only" : "read/write");
1359 err = -EBUSY;
1360 goto failed_super;
1361 }
1362 } else {
1363 /*
1364 * Try remount to setup mount states if the current
1365 * tree is not mounted and only snapshots use this sb.
1366 */
1367 err = nilfs_remount(s, &flags, data);
1368 if (err)
1369 goto failed_super;
1370 }
1371 }
1372
1373 if (sd.cno) {
1374 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1375 if (err)
1376 goto failed_super;
1377 } else {
1378 root_dentry = dget(s->s_root);
1379 }
1380
1381 if (!s_new)
1382 blkdev_put(sd.bdev, mode);
1383
1384 return root_dentry;
1385
1386 failed_super:
1387 deactivate_locked_super(s);
1388
1389 failed:
1390 if (!s_new)
1391 blkdev_put(sd.bdev, mode);
1392 return ERR_PTR(err);
1393 }
1394
1395 struct file_system_type nilfs_fs_type = {
1396 .owner = THIS_MODULE,
1397 .name = "nilfs2",
1398 .mount = nilfs_mount,
1399 .kill_sb = kill_block_super,
1400 .fs_flags = FS_REQUIRES_DEV,
1401 };
1402 MODULE_ALIAS_FS("nilfs2");
1403
nilfs_inode_init_once(void * obj)1404 static void nilfs_inode_init_once(void *obj)
1405 {
1406 struct nilfs_inode_info *ii = obj;
1407
1408 INIT_LIST_HEAD(&ii->i_dirty);
1409 #ifdef CONFIG_NILFS_XATTR
1410 init_rwsem(&ii->xattr_sem);
1411 #endif
1412 inode_init_once(&ii->vfs_inode);
1413 }
1414
nilfs_segbuf_init_once(void * obj)1415 static void nilfs_segbuf_init_once(void *obj)
1416 {
1417 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1418 }
1419
nilfs_destroy_cachep(void)1420 static void nilfs_destroy_cachep(void)
1421 {
1422 /*
1423 * Make sure all delayed rcu free inodes are flushed before we
1424 * destroy cache.
1425 */
1426 rcu_barrier();
1427
1428 kmem_cache_destroy(nilfs_inode_cachep);
1429 kmem_cache_destroy(nilfs_transaction_cachep);
1430 kmem_cache_destroy(nilfs_segbuf_cachep);
1431 kmem_cache_destroy(nilfs_btree_path_cache);
1432 }
1433
nilfs_init_cachep(void)1434 static int __init nilfs_init_cachep(void)
1435 {
1436 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1437 sizeof(struct nilfs_inode_info), 0,
1438 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
1439 nilfs_inode_init_once);
1440 if (!nilfs_inode_cachep)
1441 goto fail;
1442
1443 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1444 sizeof(struct nilfs_transaction_info), 0,
1445 SLAB_RECLAIM_ACCOUNT, NULL);
1446 if (!nilfs_transaction_cachep)
1447 goto fail;
1448
1449 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1450 sizeof(struct nilfs_segment_buffer), 0,
1451 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1452 if (!nilfs_segbuf_cachep)
1453 goto fail;
1454
1455 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1456 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1457 0, 0, NULL);
1458 if (!nilfs_btree_path_cache)
1459 goto fail;
1460
1461 return 0;
1462
1463 fail:
1464 nilfs_destroy_cachep();
1465 return -ENOMEM;
1466 }
1467
init_nilfs_fs(void)1468 static int __init init_nilfs_fs(void)
1469 {
1470 int err;
1471
1472 err = nilfs_init_cachep();
1473 if (err)
1474 goto fail;
1475
1476 err = nilfs_sysfs_init();
1477 if (err)
1478 goto free_cachep;
1479
1480 err = register_filesystem(&nilfs_fs_type);
1481 if (err)
1482 goto deinit_sysfs_entry;
1483
1484 printk(KERN_INFO "NILFS version 2 loaded\n");
1485 return 0;
1486
1487 deinit_sysfs_entry:
1488 nilfs_sysfs_exit();
1489 free_cachep:
1490 nilfs_destroy_cachep();
1491 fail:
1492 return err;
1493 }
1494
exit_nilfs_fs(void)1495 static void __exit exit_nilfs_fs(void)
1496 {
1497 nilfs_destroy_cachep();
1498 nilfs_sysfs_exit();
1499 unregister_filesystem(&nilfs_fs_type);
1500 }
1501
1502 module_init(init_nilfs_fs)
1503 module_exit(exit_nilfs_fs)
1504