xref: /openbmc/linux/fs/jfs/super.c (revision 5104d265)
1 /*
2  *   Copyright (C) International Business Machines Corp., 2000-2004
3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #include <linux/fs.h>
21 #include <linux/module.h>
22 #include <linux/parser.h>
23 #include <linux/completion.h>
24 #include <linux/vfs.h>
25 #include <linux/quotaops.h>
26 #include <linux/mount.h>
27 #include <linux/moduleparam.h>
28 #include <linux/kthread.h>
29 #include <linux/posix_acl.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/crc32.h>
33 #include <linux/slab.h>
34 #include <asm/uaccess.h>
35 #include <linux/seq_file.h>
36 #include <linux/blkdev.h>
37 
38 #include "jfs_incore.h"
39 #include "jfs_filsys.h"
40 #include "jfs_inode.h"
41 #include "jfs_metapage.h"
42 #include "jfs_superblock.h"
43 #include "jfs_dmap.h"
44 #include "jfs_imap.h"
45 #include "jfs_acl.h"
46 #include "jfs_debug.h"
47 
48 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
49 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
50 MODULE_LICENSE("GPL");
51 
52 static struct kmem_cache * jfs_inode_cachep;
53 
54 static const struct super_operations jfs_super_operations;
55 static const struct export_operations jfs_export_operations;
56 static struct file_system_type jfs_fs_type;
57 
58 #define MAX_COMMIT_THREADS 64
59 static int commit_threads = 0;
60 module_param(commit_threads, int, 0);
61 MODULE_PARM_DESC(commit_threads, "Number of commit threads");
62 
63 static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
64 struct task_struct *jfsIOthread;
65 struct task_struct *jfsSyncThread;
66 
67 #ifdef CONFIG_JFS_DEBUG
68 int jfsloglevel = JFS_LOGLEVEL_WARN;
69 module_param(jfsloglevel, int, 0644);
70 MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
71 #endif
72 
73 static void jfs_handle_error(struct super_block *sb)
74 {
75 	struct jfs_sb_info *sbi = JFS_SBI(sb);
76 
77 	if (sb->s_flags & MS_RDONLY)
78 		return;
79 
80 	updateSuper(sb, FM_DIRTY);
81 
82 	if (sbi->flag & JFS_ERR_PANIC)
83 		panic("JFS (device %s): panic forced after error\n",
84 			sb->s_id);
85 	else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
86 		jfs_err("ERROR: (device %s): remounting filesystem "
87 			"as read-only\n",
88 			sb->s_id);
89 		sb->s_flags |= MS_RDONLY;
90 	}
91 
92 	/* nothing is done for continue beyond marking the superblock dirty */
93 }
94 
95 void jfs_error(struct super_block *sb, const char *fmt, ...)
96 {
97 	struct va_format vaf;
98 	va_list args;
99 
100 	va_start(args, fmt);
101 
102 	vaf.fmt = fmt;
103 	vaf.va = &args;
104 
105 	pr_err("ERROR: (device %s): %pf: %pV\n",
106 	       sb->s_id, __builtin_return_address(0), &vaf);
107 
108 	va_end(args);
109 
110 	jfs_handle_error(sb);
111 }
112 
113 static struct inode *jfs_alloc_inode(struct super_block *sb)
114 {
115 	struct jfs_inode_info *jfs_inode;
116 
117 	jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
118 	if (!jfs_inode)
119 		return NULL;
120 	return &jfs_inode->vfs_inode;
121 }
122 
123 static void jfs_i_callback(struct rcu_head *head)
124 {
125 	struct inode *inode = container_of(head, struct inode, i_rcu);
126 	struct jfs_inode_info *ji = JFS_IP(inode);
127 	kmem_cache_free(jfs_inode_cachep, ji);
128 }
129 
130 static void jfs_destroy_inode(struct inode *inode)
131 {
132 	struct jfs_inode_info *ji = JFS_IP(inode);
133 
134 	BUG_ON(!list_empty(&ji->anon_inode_list));
135 
136 	spin_lock_irq(&ji->ag_lock);
137 	if (ji->active_ag != -1) {
138 		struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
139 		atomic_dec(&bmap->db_active[ji->active_ag]);
140 		ji->active_ag = -1;
141 	}
142 	spin_unlock_irq(&ji->ag_lock);
143 	call_rcu(&inode->i_rcu, jfs_i_callback);
144 }
145 
146 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
147 {
148 	struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
149 	s64 maxinodes;
150 	struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
151 
152 	jfs_info("In jfs_statfs");
153 	buf->f_type = JFS_SUPER_MAGIC;
154 	buf->f_bsize = sbi->bsize;
155 	buf->f_blocks = sbi->bmap->db_mapsize;
156 	buf->f_bfree = sbi->bmap->db_nfree;
157 	buf->f_bavail = sbi->bmap->db_nfree;
158 	/*
159 	 * If we really return the number of allocated & free inodes, some
160 	 * applications will fail because they won't see enough free inodes.
161 	 * We'll try to calculate some guess as to how many inodes we can
162 	 * really allocate
163 	 *
164 	 * buf->f_files = atomic_read(&imap->im_numinos);
165 	 * buf->f_ffree = atomic_read(&imap->im_numfree);
166 	 */
167 	maxinodes = min((s64) atomic_read(&imap->im_numinos) +
168 			((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
169 			 << L2INOSPEREXT), (s64) 0xffffffffLL);
170 	buf->f_files = maxinodes;
171 	buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
172 				    atomic_read(&imap->im_numfree));
173 	buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
174 	buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
175 					sizeof(sbi->uuid)/2);
176 
177 	buf->f_namelen = JFS_NAME_MAX;
178 	return 0;
179 }
180 
181 static void jfs_put_super(struct super_block *sb)
182 {
183 	struct jfs_sb_info *sbi = JFS_SBI(sb);
184 	int rc;
185 
186 	jfs_info("In jfs_put_super");
187 
188 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
189 
190 	rc = jfs_umount(sb);
191 	if (rc)
192 		jfs_err("jfs_umount failed with return code %d", rc);
193 
194 	unload_nls(sbi->nls_tab);
195 
196 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
197 	iput(sbi->direct_inode);
198 
199 	kfree(sbi);
200 }
201 
202 enum {
203 	Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
204 	Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
205 	Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask,
206 	Opt_discard, Opt_nodiscard, Opt_discard_minblk
207 };
208 
209 static const match_table_t tokens = {
210 	{Opt_integrity, "integrity"},
211 	{Opt_nointegrity, "nointegrity"},
212 	{Opt_iocharset, "iocharset=%s"},
213 	{Opt_resize, "resize=%u"},
214 	{Opt_resize_nosize, "resize"},
215 	{Opt_errors, "errors=%s"},
216 	{Opt_ignore, "noquota"},
217 	{Opt_ignore, "quota"},
218 	{Opt_usrquota, "usrquota"},
219 	{Opt_grpquota, "grpquota"},
220 	{Opt_uid, "uid=%u"},
221 	{Opt_gid, "gid=%u"},
222 	{Opt_umask, "umask=%u"},
223 	{Opt_discard, "discard"},
224 	{Opt_nodiscard, "nodiscard"},
225 	{Opt_discard_minblk, "discard=%u"},
226 	{Opt_err, NULL}
227 };
228 
229 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
230 			 int *flag)
231 {
232 	void *nls_map = (void *)-1;	/* -1: no change;  NULL: none */
233 	char *p;
234 	struct jfs_sb_info *sbi = JFS_SBI(sb);
235 
236 	*newLVSize = 0;
237 
238 	if (!options)
239 		return 1;
240 
241 	while ((p = strsep(&options, ",")) != NULL) {
242 		substring_t args[MAX_OPT_ARGS];
243 		int token;
244 		if (!*p)
245 			continue;
246 
247 		token = match_token(p, tokens, args);
248 		switch (token) {
249 		case Opt_integrity:
250 			*flag &= ~JFS_NOINTEGRITY;
251 			break;
252 		case Opt_nointegrity:
253 			*flag |= JFS_NOINTEGRITY;
254 			break;
255 		case Opt_ignore:
256 			/* Silently ignore the quota options */
257 			/* Don't do anything ;-) */
258 			break;
259 		case Opt_iocharset:
260 			if (nls_map && nls_map != (void *) -1)
261 				unload_nls(nls_map);
262 			if (!strcmp(args[0].from, "none"))
263 				nls_map = NULL;
264 			else {
265 				nls_map = load_nls(args[0].from);
266 				if (!nls_map) {
267 					pr_err("JFS: charset not found\n");
268 					goto cleanup;
269 				}
270 			}
271 			break;
272 		case Opt_resize:
273 		{
274 			char *resize = args[0].from;
275 			*newLVSize = simple_strtoull(resize, &resize, 0);
276 			break;
277 		}
278 		case Opt_resize_nosize:
279 		{
280 			*newLVSize = sb->s_bdev->bd_inode->i_size >>
281 				sb->s_blocksize_bits;
282 			if (*newLVSize == 0)
283 				pr_err("JFS: Cannot determine volume size\n");
284 			break;
285 		}
286 		case Opt_errors:
287 		{
288 			char *errors = args[0].from;
289 			if (!errors || !*errors)
290 				goto cleanup;
291 			if (!strcmp(errors, "continue")) {
292 				*flag &= ~JFS_ERR_REMOUNT_RO;
293 				*flag &= ~JFS_ERR_PANIC;
294 				*flag |= JFS_ERR_CONTINUE;
295 			} else if (!strcmp(errors, "remount-ro")) {
296 				*flag &= ~JFS_ERR_CONTINUE;
297 				*flag &= ~JFS_ERR_PANIC;
298 				*flag |= JFS_ERR_REMOUNT_RO;
299 			} else if (!strcmp(errors, "panic")) {
300 				*flag &= ~JFS_ERR_CONTINUE;
301 				*flag &= ~JFS_ERR_REMOUNT_RO;
302 				*flag |= JFS_ERR_PANIC;
303 			} else {
304 				pr_err("JFS: %s is an invalid error handler\n",
305 				       errors);
306 				goto cleanup;
307 			}
308 			break;
309 		}
310 
311 #ifdef CONFIG_QUOTA
312 		case Opt_quota:
313 		case Opt_usrquota:
314 			*flag |= JFS_USRQUOTA;
315 			break;
316 		case Opt_grpquota:
317 			*flag |= JFS_GRPQUOTA;
318 			break;
319 #else
320 		case Opt_usrquota:
321 		case Opt_grpquota:
322 		case Opt_quota:
323 			pr_err("JFS: quota operations not supported\n");
324 			break;
325 #endif
326 		case Opt_uid:
327 		{
328 			char *uid = args[0].from;
329 			uid_t val = simple_strtoul(uid, &uid, 0);
330 			sbi->uid = make_kuid(current_user_ns(), val);
331 			if (!uid_valid(sbi->uid))
332 				goto cleanup;
333 			break;
334 		}
335 
336 		case Opt_gid:
337 		{
338 			char *gid = args[0].from;
339 			gid_t val = simple_strtoul(gid, &gid, 0);
340 			sbi->gid = make_kgid(current_user_ns(), val);
341 			if (!gid_valid(sbi->gid))
342 				goto cleanup;
343 			break;
344 		}
345 
346 		case Opt_umask:
347 		{
348 			char *umask = args[0].from;
349 			sbi->umask = simple_strtoul(umask, &umask, 8);
350 			if (sbi->umask & ~0777) {
351 				pr_err("JFS: Invalid value of umask\n");
352 				goto cleanup;
353 			}
354 			break;
355 		}
356 
357 		case Opt_discard:
358 		{
359 			struct request_queue *q = bdev_get_queue(sb->s_bdev);
360 			/* if set to 1, even copying files will cause
361 			 * trimming :O
362 			 * -> user has more control over the online trimming
363 			 */
364 			sbi->minblks_trim = 64;
365 			if (blk_queue_discard(q)) {
366 				*flag |= JFS_DISCARD;
367 			} else {
368 				pr_err("JFS: discard option " \
369 					"not supported on device\n");
370 			}
371 			break;
372 		}
373 
374 		case Opt_nodiscard:
375 			*flag &= ~JFS_DISCARD;
376 			break;
377 
378 		case Opt_discard_minblk:
379 		{
380 			struct request_queue *q = bdev_get_queue(sb->s_bdev);
381 			char *minblks_trim = args[0].from;
382 			if (blk_queue_discard(q)) {
383 				*flag |= JFS_DISCARD;
384 				sbi->minblks_trim = simple_strtoull(
385 					minblks_trim, &minblks_trim, 0);
386 			} else {
387 				pr_err("JFS: discard option " \
388 					"not supported on device\n");
389 			}
390 			break;
391 		}
392 
393 		default:
394 			printk("jfs: Unrecognized mount option \"%s\" "
395 					" or missing value\n", p);
396 			goto cleanup;
397 		}
398 	}
399 
400 	if (nls_map != (void *) -1) {
401 		/* Discard old (if remount) */
402 		unload_nls(sbi->nls_tab);
403 		sbi->nls_tab = nls_map;
404 	}
405 	return 1;
406 
407 cleanup:
408 	if (nls_map && nls_map != (void *) -1)
409 		unload_nls(nls_map);
410 	return 0;
411 }
412 
413 static int jfs_remount(struct super_block *sb, int *flags, char *data)
414 {
415 	s64 newLVSize = 0;
416 	int rc = 0;
417 	int flag = JFS_SBI(sb)->flag;
418 	int ret;
419 
420 	if (!parse_options(data, sb, &newLVSize, &flag)) {
421 		return -EINVAL;
422 	}
423 
424 	if (newLVSize) {
425 		if (sb->s_flags & MS_RDONLY) {
426 			pr_err("JFS: resize requires volume" \
427 				" to be mounted read-write\n");
428 			return -EROFS;
429 		}
430 		rc = jfs_extendfs(sb, newLVSize, 0);
431 		if (rc)
432 			return rc;
433 	}
434 
435 	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
436 		/*
437 		 * Invalidate any previously read metadata.  fsck may have
438 		 * changed the on-disk data since we mounted r/o
439 		 */
440 		truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
441 
442 		JFS_SBI(sb)->flag = flag;
443 		ret = jfs_mount_rw(sb, 1);
444 
445 		/* mark the fs r/w for quota activity */
446 		sb->s_flags &= ~MS_RDONLY;
447 
448 		dquot_resume(sb, -1);
449 		return ret;
450 	}
451 	if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
452 		rc = dquot_suspend(sb, -1);
453 		if (rc < 0) {
454 			return rc;
455 		}
456 		rc = jfs_umount_rw(sb);
457 		JFS_SBI(sb)->flag = flag;
458 		return rc;
459 	}
460 	if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
461 		if (!(sb->s_flags & MS_RDONLY)) {
462 			rc = jfs_umount_rw(sb);
463 			if (rc)
464 				return rc;
465 
466 			JFS_SBI(sb)->flag = flag;
467 			ret = jfs_mount_rw(sb, 1);
468 			return ret;
469 		}
470 	JFS_SBI(sb)->flag = flag;
471 
472 	return 0;
473 }
474 
475 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
476 {
477 	struct jfs_sb_info *sbi;
478 	struct inode *inode;
479 	int rc;
480 	s64 newLVSize = 0;
481 	int flag, ret = -EINVAL;
482 
483 	jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
484 
485 	if (!new_valid_dev(sb->s_bdev->bd_dev))
486 		return -EOVERFLOW;
487 
488 	sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
489 	if (!sbi)
490 		return -ENOMEM;
491 
492 	sb->s_fs_info = sbi;
493 	sb->s_max_links = JFS_LINK_MAX;
494 	sbi->sb = sb;
495 	sbi->uid = INVALID_UID;
496 	sbi->gid = INVALID_GID;
497 	sbi->umask = -1;
498 
499 	/* initialize the mount flag and determine the default error handler */
500 	flag = JFS_ERR_REMOUNT_RO;
501 
502 	if (!parse_options((char *) data, sb, &newLVSize, &flag))
503 		goto out_kfree;
504 	sbi->flag = flag;
505 
506 #ifdef CONFIG_JFS_POSIX_ACL
507 	sb->s_flags |= MS_POSIXACL;
508 #endif
509 
510 	if (newLVSize) {
511 		pr_err("resize option for remount only\n");
512 		goto out_kfree;
513 	}
514 
515 	/*
516 	 * Initialize blocksize to 4K.
517 	 */
518 	sb_set_blocksize(sb, PSIZE);
519 
520 	/*
521 	 * Set method vectors.
522 	 */
523 	sb->s_op = &jfs_super_operations;
524 	sb->s_export_op = &jfs_export_operations;
525 #ifdef CONFIG_QUOTA
526 	sb->dq_op = &dquot_operations;
527 	sb->s_qcop = &dquot_quotactl_ops;
528 #endif
529 
530 	/*
531 	 * Initialize direct-mapping inode/address-space
532 	 */
533 	inode = new_inode(sb);
534 	if (inode == NULL) {
535 		ret = -ENOMEM;
536 		goto out_unload;
537 	}
538 	inode->i_ino = 0;
539 	inode->i_size = sb->s_bdev->bd_inode->i_size;
540 	inode->i_mapping->a_ops = &jfs_metapage_aops;
541 	insert_inode_hash(inode);
542 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
543 
544 	sbi->direct_inode = inode;
545 
546 	rc = jfs_mount(sb);
547 	if (rc) {
548 		if (!silent) {
549 			jfs_err("jfs_mount failed w/return code = %d", rc);
550 		}
551 		goto out_mount_failed;
552 	}
553 	if (sb->s_flags & MS_RDONLY)
554 		sbi->log = NULL;
555 	else {
556 		rc = jfs_mount_rw(sb, 0);
557 		if (rc) {
558 			if (!silent) {
559 				jfs_err("jfs_mount_rw failed, return code = %d",
560 					rc);
561 			}
562 			goto out_no_rw;
563 		}
564 	}
565 
566 	sb->s_magic = JFS_SUPER_MAGIC;
567 
568 	if (sbi->mntflag & JFS_OS2)
569 		sb->s_d_op = &jfs_ci_dentry_operations;
570 
571 	inode = jfs_iget(sb, ROOT_I);
572 	if (IS_ERR(inode)) {
573 		ret = PTR_ERR(inode);
574 		goto out_no_rw;
575 	}
576 	sb->s_root = d_make_root(inode);
577 	if (!sb->s_root)
578 		goto out_no_root;
579 
580 	/* logical blocks are represented by 40 bits in pxd_t, etc. */
581 	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
582 #if BITS_PER_LONG == 32
583 	/*
584 	 * Page cache is indexed by long.
585 	 * I would use MAX_LFS_FILESIZE, but it's only half as big
586 	 */
587 	sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
588 #endif
589 	sb->s_time_gran = 1;
590 	return 0;
591 
592 out_no_root:
593 	jfs_err("jfs_read_super: get root dentry failed");
594 
595 out_no_rw:
596 	rc = jfs_umount(sb);
597 	if (rc) {
598 		jfs_err("jfs_umount failed with return code %d", rc);
599 	}
600 out_mount_failed:
601 	filemap_write_and_wait(sbi->direct_inode->i_mapping);
602 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
603 	make_bad_inode(sbi->direct_inode);
604 	iput(sbi->direct_inode);
605 	sbi->direct_inode = NULL;
606 out_unload:
607 	if (sbi->nls_tab)
608 		unload_nls(sbi->nls_tab);
609 out_kfree:
610 	kfree(sbi);
611 	return ret;
612 }
613 
614 static int jfs_freeze(struct super_block *sb)
615 {
616 	struct jfs_sb_info *sbi = JFS_SBI(sb);
617 	struct jfs_log *log = sbi->log;
618 	int rc = 0;
619 
620 	if (!(sb->s_flags & MS_RDONLY)) {
621 		txQuiesce(sb);
622 		rc = lmLogShutdown(log);
623 		if (rc) {
624 			jfs_error(sb, "lmLogShutdown failed\n");
625 
626 			/* let operations fail rather than hang */
627 			txResume(sb);
628 
629 			return rc;
630 		}
631 		rc = updateSuper(sb, FM_CLEAN);
632 		if (rc) {
633 			jfs_err("jfs_freeze: updateSuper failed\n");
634 			/*
635 			 * Don't fail here. Everything succeeded except
636 			 * marking the superblock clean, so there's really
637 			 * no harm in leaving it frozen for now.
638 			 */
639 		}
640 	}
641 	return 0;
642 }
643 
644 static int jfs_unfreeze(struct super_block *sb)
645 {
646 	struct jfs_sb_info *sbi = JFS_SBI(sb);
647 	struct jfs_log *log = sbi->log;
648 	int rc = 0;
649 
650 	if (!(sb->s_flags & MS_RDONLY)) {
651 		rc = updateSuper(sb, FM_MOUNT);
652 		if (rc) {
653 			jfs_error(sb, "updateSuper failed\n");
654 			goto out;
655 		}
656 		rc = lmLogInit(log);
657 		if (rc)
658 			jfs_error(sb, "lmLogInit failed\n");
659 out:
660 		txResume(sb);
661 	}
662 	return rc;
663 }
664 
665 static struct dentry *jfs_do_mount(struct file_system_type *fs_type,
666 	int flags, const char *dev_name, void *data)
667 {
668 	return mount_bdev(fs_type, flags, dev_name, data, jfs_fill_super);
669 }
670 
671 static int jfs_sync_fs(struct super_block *sb, int wait)
672 {
673 	struct jfs_log *log = JFS_SBI(sb)->log;
674 
675 	/* log == NULL indicates read-only mount */
676 	if (log) {
677 		/*
678 		 * Write quota structures to quota file, sync_blockdev() will
679 		 * write them to disk later
680 		 */
681 		dquot_writeback_dquots(sb, -1);
682 		jfs_flush_journal(log, wait);
683 		jfs_syncpt(log, 0);
684 	}
685 
686 	return 0;
687 }
688 
689 static int jfs_show_options(struct seq_file *seq, struct dentry *root)
690 {
691 	struct jfs_sb_info *sbi = JFS_SBI(root->d_sb);
692 
693 	if (uid_valid(sbi->uid))
694 		seq_printf(seq, ",uid=%d", from_kuid(&init_user_ns, sbi->uid));
695 	if (gid_valid(sbi->gid))
696 		seq_printf(seq, ",gid=%d", from_kgid(&init_user_ns, sbi->gid));
697 	if (sbi->umask != -1)
698 		seq_printf(seq, ",umask=%03o", sbi->umask);
699 	if (sbi->flag & JFS_NOINTEGRITY)
700 		seq_puts(seq, ",nointegrity");
701 	if (sbi->flag & JFS_DISCARD)
702 		seq_printf(seq, ",discard=%u", sbi->minblks_trim);
703 	if (sbi->nls_tab)
704 		seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
705 	if (sbi->flag & JFS_ERR_CONTINUE)
706 		seq_printf(seq, ",errors=continue");
707 	if (sbi->flag & JFS_ERR_PANIC)
708 		seq_printf(seq, ",errors=panic");
709 
710 #ifdef CONFIG_QUOTA
711 	if (sbi->flag & JFS_USRQUOTA)
712 		seq_puts(seq, ",usrquota");
713 
714 	if (sbi->flag & JFS_GRPQUOTA)
715 		seq_puts(seq, ",grpquota");
716 #endif
717 
718 	return 0;
719 }
720 
721 #ifdef CONFIG_QUOTA
722 
723 /* Read data from quotafile - avoid pagecache and such because we cannot afford
724  * acquiring the locks... As quota files are never truncated and quota code
725  * itself serializes the operations (and no one else should touch the files)
726  * we don't have to be afraid of races */
727 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
728 			      size_t len, loff_t off)
729 {
730 	struct inode *inode = sb_dqopt(sb)->files[type];
731 	sector_t blk = off >> sb->s_blocksize_bits;
732 	int err = 0;
733 	int offset = off & (sb->s_blocksize - 1);
734 	int tocopy;
735 	size_t toread;
736 	struct buffer_head tmp_bh;
737 	struct buffer_head *bh;
738 	loff_t i_size = i_size_read(inode);
739 
740 	if (off > i_size)
741 		return 0;
742 	if (off+len > i_size)
743 		len = i_size-off;
744 	toread = len;
745 	while (toread > 0) {
746 		tocopy = sb->s_blocksize - offset < toread ?
747 				sb->s_blocksize - offset : toread;
748 
749 		tmp_bh.b_state = 0;
750 		tmp_bh.b_size = 1 << inode->i_blkbits;
751 		err = jfs_get_block(inode, blk, &tmp_bh, 0);
752 		if (err)
753 			return err;
754 		if (!buffer_mapped(&tmp_bh))	/* A hole? */
755 			memset(data, 0, tocopy);
756 		else {
757 			bh = sb_bread(sb, tmp_bh.b_blocknr);
758 			if (!bh)
759 				return -EIO;
760 			memcpy(data, bh->b_data+offset, tocopy);
761 			brelse(bh);
762 		}
763 		offset = 0;
764 		toread -= tocopy;
765 		data += tocopy;
766 		blk++;
767 	}
768 	return len;
769 }
770 
771 /* Write to quotafile */
772 static ssize_t jfs_quota_write(struct super_block *sb, int type,
773 			       const char *data, size_t len, loff_t off)
774 {
775 	struct inode *inode = sb_dqopt(sb)->files[type];
776 	sector_t blk = off >> sb->s_blocksize_bits;
777 	int err = 0;
778 	int offset = off & (sb->s_blocksize - 1);
779 	int tocopy;
780 	size_t towrite = len;
781 	struct buffer_head tmp_bh;
782 	struct buffer_head *bh;
783 
784 	mutex_lock(&inode->i_mutex);
785 	while (towrite > 0) {
786 		tocopy = sb->s_blocksize - offset < towrite ?
787 				sb->s_blocksize - offset : towrite;
788 
789 		tmp_bh.b_state = 0;
790 		tmp_bh.b_size = 1 << inode->i_blkbits;
791 		err = jfs_get_block(inode, blk, &tmp_bh, 1);
792 		if (err)
793 			goto out;
794 		if (offset || tocopy != sb->s_blocksize)
795 			bh = sb_bread(sb, tmp_bh.b_blocknr);
796 		else
797 			bh = sb_getblk(sb, tmp_bh.b_blocknr);
798 		if (!bh) {
799 			err = -EIO;
800 			goto out;
801 		}
802 		lock_buffer(bh);
803 		memcpy(bh->b_data+offset, data, tocopy);
804 		flush_dcache_page(bh->b_page);
805 		set_buffer_uptodate(bh);
806 		mark_buffer_dirty(bh);
807 		unlock_buffer(bh);
808 		brelse(bh);
809 		offset = 0;
810 		towrite -= tocopy;
811 		data += tocopy;
812 		blk++;
813 	}
814 out:
815 	if (len == towrite) {
816 		mutex_unlock(&inode->i_mutex);
817 		return err;
818 	}
819 	if (inode->i_size < off+len-towrite)
820 		i_size_write(inode, off+len-towrite);
821 	inode->i_version++;
822 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
823 	mark_inode_dirty(inode);
824 	mutex_unlock(&inode->i_mutex);
825 	return len - towrite;
826 }
827 
828 #endif
829 
830 static const struct super_operations jfs_super_operations = {
831 	.alloc_inode	= jfs_alloc_inode,
832 	.destroy_inode	= jfs_destroy_inode,
833 	.dirty_inode	= jfs_dirty_inode,
834 	.write_inode	= jfs_write_inode,
835 	.evict_inode	= jfs_evict_inode,
836 	.put_super	= jfs_put_super,
837 	.sync_fs	= jfs_sync_fs,
838 	.freeze_fs	= jfs_freeze,
839 	.unfreeze_fs	= jfs_unfreeze,
840 	.statfs		= jfs_statfs,
841 	.remount_fs	= jfs_remount,
842 	.show_options	= jfs_show_options,
843 #ifdef CONFIG_QUOTA
844 	.quota_read	= jfs_quota_read,
845 	.quota_write	= jfs_quota_write,
846 #endif
847 };
848 
849 static const struct export_operations jfs_export_operations = {
850 	.fh_to_dentry	= jfs_fh_to_dentry,
851 	.fh_to_parent	= jfs_fh_to_parent,
852 	.get_parent	= jfs_get_parent,
853 };
854 
855 static struct file_system_type jfs_fs_type = {
856 	.owner		= THIS_MODULE,
857 	.name		= "jfs",
858 	.mount		= jfs_do_mount,
859 	.kill_sb	= kill_block_super,
860 	.fs_flags	= FS_REQUIRES_DEV,
861 };
862 MODULE_ALIAS_FS("jfs");
863 
864 static void init_once(void *foo)
865 {
866 	struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
867 
868 	memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
869 	INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
870 	init_rwsem(&jfs_ip->rdwrlock);
871 	mutex_init(&jfs_ip->commit_mutex);
872 	init_rwsem(&jfs_ip->xattr_sem);
873 	spin_lock_init(&jfs_ip->ag_lock);
874 	jfs_ip->active_ag = -1;
875 	inode_init_once(&jfs_ip->vfs_inode);
876 }
877 
878 static int __init init_jfs_fs(void)
879 {
880 	int i;
881 	int rc;
882 
883 	jfs_inode_cachep =
884 	    kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
885 			    SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
886 			    init_once);
887 	if (jfs_inode_cachep == NULL)
888 		return -ENOMEM;
889 
890 	/*
891 	 * Metapage initialization
892 	 */
893 	rc = metapage_init();
894 	if (rc) {
895 		jfs_err("metapage_init failed w/rc = %d", rc);
896 		goto free_slab;
897 	}
898 
899 	/*
900 	 * Transaction Manager initialization
901 	 */
902 	rc = txInit();
903 	if (rc) {
904 		jfs_err("txInit failed w/rc = %d", rc);
905 		goto free_metapage;
906 	}
907 
908 	/*
909 	 * I/O completion thread (endio)
910 	 */
911 	jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
912 	if (IS_ERR(jfsIOthread)) {
913 		rc = PTR_ERR(jfsIOthread);
914 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
915 		goto end_txmngr;
916 	}
917 
918 	if (commit_threads < 1)
919 		commit_threads = num_online_cpus();
920 	if (commit_threads > MAX_COMMIT_THREADS)
921 		commit_threads = MAX_COMMIT_THREADS;
922 
923 	for (i = 0; i < commit_threads; i++) {
924 		jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
925 		if (IS_ERR(jfsCommitThread[i])) {
926 			rc = PTR_ERR(jfsCommitThread[i]);
927 			jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
928 			commit_threads = i;
929 			goto kill_committask;
930 		}
931 	}
932 
933 	jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
934 	if (IS_ERR(jfsSyncThread)) {
935 		rc = PTR_ERR(jfsSyncThread);
936 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
937 		goto kill_committask;
938 	}
939 
940 #ifdef PROC_FS_JFS
941 	jfs_proc_init();
942 #endif
943 
944 	rc = register_filesystem(&jfs_fs_type);
945 	if (!rc)
946 		return 0;
947 
948 #ifdef PROC_FS_JFS
949 	jfs_proc_clean();
950 #endif
951 	kthread_stop(jfsSyncThread);
952 kill_committask:
953 	for (i = 0; i < commit_threads; i++)
954 		kthread_stop(jfsCommitThread[i]);
955 	kthread_stop(jfsIOthread);
956 end_txmngr:
957 	txExit();
958 free_metapage:
959 	metapage_exit();
960 free_slab:
961 	kmem_cache_destroy(jfs_inode_cachep);
962 	return rc;
963 }
964 
965 static void __exit exit_jfs_fs(void)
966 {
967 	int i;
968 
969 	jfs_info("exit_jfs_fs called");
970 
971 	txExit();
972 	metapage_exit();
973 
974 	kthread_stop(jfsIOthread);
975 	for (i = 0; i < commit_threads; i++)
976 		kthread_stop(jfsCommitThread[i]);
977 	kthread_stop(jfsSyncThread);
978 #ifdef PROC_FS_JFS
979 	jfs_proc_clean();
980 #endif
981 	unregister_filesystem(&jfs_fs_type);
982 
983 	/*
984 	 * Make sure all delayed rcu free inodes are flushed before we
985 	 * destroy cache.
986 	 */
987 	rcu_barrier();
988 	kmem_cache_destroy(jfs_inode_cachep);
989 }
990 
991 module_init(init_jfs_fs)
992 module_exit(exit_jfs_fs)
993