xref: /openbmc/linux/fs/jfs/super.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 
37 #include "jfs_incore.h"
38 #include "jfs_filsys.h"
39 #include "jfs_inode.h"
40 #include "jfs_metapage.h"
41 #include "jfs_superblock.h"
42 #include "jfs_dmap.h"
43 #include "jfs_imap.h"
44 #include "jfs_acl.h"
45 #include "jfs_debug.h"
46 
47 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
48 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
49 MODULE_LICENSE("GPL");
50 
51 static struct kmem_cache * jfs_inode_cachep;
52 
53 static const struct super_operations jfs_super_operations;
54 static const struct export_operations jfs_export_operations;
55 static struct file_system_type jfs_fs_type;
56 
57 #define MAX_COMMIT_THREADS 64
58 static int commit_threads = 0;
59 module_param(commit_threads, int, 0);
60 MODULE_PARM_DESC(commit_threads, "Number of commit threads");
61 
62 static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
63 struct task_struct *jfsIOthread;
64 struct task_struct *jfsSyncThread;
65 
66 #ifdef CONFIG_JFS_DEBUG
67 int jfsloglevel = JFS_LOGLEVEL_WARN;
68 module_param(jfsloglevel, int, 0644);
69 MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
70 #endif
71 
72 static void jfs_handle_error(struct super_block *sb)
73 {
74 	struct jfs_sb_info *sbi = JFS_SBI(sb);
75 
76 	if (sb->s_flags & MS_RDONLY)
77 		return;
78 
79 	updateSuper(sb, FM_DIRTY);
80 
81 	if (sbi->flag & JFS_ERR_PANIC)
82 		panic("JFS (device %s): panic forced after error\n",
83 			sb->s_id);
84 	else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
85 		jfs_err("ERROR: (device %s): remounting filesystem "
86 			"as read-only\n",
87 			sb->s_id);
88 		sb->s_flags |= MS_RDONLY;
89 	}
90 
91 	/* nothing is done for continue beyond marking the superblock dirty */
92 }
93 
94 void jfs_error(struct super_block *sb, const char * function, ...)
95 {
96 	static char error_buf[256];
97 	va_list args;
98 
99 	va_start(args, function);
100 	vsnprintf(error_buf, sizeof(error_buf), function, args);
101 	va_end(args);
102 
103 	printk(KERN_ERR "ERROR: (device %s): %s\n", sb->s_id, error_buf);
104 
105 	jfs_handle_error(sb);
106 }
107 
108 static struct inode *jfs_alloc_inode(struct super_block *sb)
109 {
110 	struct jfs_inode_info *jfs_inode;
111 
112 	jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
113 	if (!jfs_inode)
114 		return NULL;
115 	return &jfs_inode->vfs_inode;
116 }
117 
118 static void jfs_destroy_inode(struct inode *inode)
119 {
120 	struct jfs_inode_info *ji = JFS_IP(inode);
121 
122 	BUG_ON(!list_empty(&ji->anon_inode_list));
123 
124 	spin_lock_irq(&ji->ag_lock);
125 	if (ji->active_ag != -1) {
126 		struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
127 		atomic_dec(&bmap->db_active[ji->active_ag]);
128 		ji->active_ag = -1;
129 	}
130 	spin_unlock_irq(&ji->ag_lock);
131 	kmem_cache_free(jfs_inode_cachep, ji);
132 }
133 
134 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
135 {
136 	struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
137 	s64 maxinodes;
138 	struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
139 
140 	jfs_info("In jfs_statfs");
141 	buf->f_type = JFS_SUPER_MAGIC;
142 	buf->f_bsize = sbi->bsize;
143 	buf->f_blocks = sbi->bmap->db_mapsize;
144 	buf->f_bfree = sbi->bmap->db_nfree;
145 	buf->f_bavail = sbi->bmap->db_nfree;
146 	/*
147 	 * If we really return the number of allocated & free inodes, some
148 	 * applications will fail because they won't see enough free inodes.
149 	 * We'll try to calculate some guess as to how may inodes we can
150 	 * really allocate
151 	 *
152 	 * buf->f_files = atomic_read(&imap->im_numinos);
153 	 * buf->f_ffree = atomic_read(&imap->im_numfree);
154 	 */
155 	maxinodes = min((s64) atomic_read(&imap->im_numinos) +
156 			((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
157 			 << L2INOSPEREXT), (s64) 0xffffffffLL);
158 	buf->f_files = maxinodes;
159 	buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
160 				    atomic_read(&imap->im_numfree));
161 	buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
162 	buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
163 					sizeof(sbi->uuid)/2);
164 
165 	buf->f_namelen = JFS_NAME_MAX;
166 	return 0;
167 }
168 
169 static void jfs_put_super(struct super_block *sb)
170 {
171 	struct jfs_sb_info *sbi = JFS_SBI(sb);
172 	int rc;
173 
174 	jfs_info("In jfs_put_super");
175 
176 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
177 
178 	rc = jfs_umount(sb);
179 	if (rc)
180 		jfs_err("jfs_umount failed with return code %d", rc);
181 
182 	unload_nls(sbi->nls_tab);
183 
184 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
185 	iput(sbi->direct_inode);
186 
187 	kfree(sbi);
188 }
189 
190 enum {
191 	Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
192 	Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
193 	Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
194 };
195 
196 static const match_table_t tokens = {
197 	{Opt_integrity, "integrity"},
198 	{Opt_nointegrity, "nointegrity"},
199 	{Opt_iocharset, "iocharset=%s"},
200 	{Opt_resize, "resize=%u"},
201 	{Opt_resize_nosize, "resize"},
202 	{Opt_errors, "errors=%s"},
203 	{Opt_ignore, "noquota"},
204 	{Opt_ignore, "quota"},
205 	{Opt_usrquota, "usrquota"},
206 	{Opt_grpquota, "grpquota"},
207 	{Opt_uid, "uid=%u"},
208 	{Opt_gid, "gid=%u"},
209 	{Opt_umask, "umask=%u"},
210 	{Opt_err, NULL}
211 };
212 
213 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
214 			 int *flag)
215 {
216 	void *nls_map = (void *)-1;	/* -1: no change;  NULL: none */
217 	char *p;
218 	struct jfs_sb_info *sbi = JFS_SBI(sb);
219 
220 	*newLVSize = 0;
221 
222 	if (!options)
223 		return 1;
224 
225 	while ((p = strsep(&options, ",")) != NULL) {
226 		substring_t args[MAX_OPT_ARGS];
227 		int token;
228 		if (!*p)
229 			continue;
230 
231 		token = match_token(p, tokens, args);
232 		switch (token) {
233 		case Opt_integrity:
234 			*flag &= ~JFS_NOINTEGRITY;
235 			break;
236 		case Opt_nointegrity:
237 			*flag |= JFS_NOINTEGRITY;
238 			break;
239 		case Opt_ignore:
240 			/* Silently ignore the quota options */
241 			/* Don't do anything ;-) */
242 			break;
243 		case Opt_iocharset:
244 			if (nls_map && nls_map != (void *) -1)
245 				unload_nls(nls_map);
246 			if (!strcmp(args[0].from, "none"))
247 				nls_map = NULL;
248 			else {
249 				nls_map = load_nls(args[0].from);
250 				if (!nls_map) {
251 					printk(KERN_ERR
252 					       "JFS: charset not found\n");
253 					goto cleanup;
254 				}
255 			}
256 			break;
257 		case Opt_resize:
258 		{
259 			char *resize = args[0].from;
260 			*newLVSize = simple_strtoull(resize, &resize, 0);
261 			break;
262 		}
263 		case Opt_resize_nosize:
264 		{
265 			*newLVSize = sb->s_bdev->bd_inode->i_size >>
266 				sb->s_blocksize_bits;
267 			if (*newLVSize == 0)
268 				printk(KERN_ERR
269 				       "JFS: Cannot determine volume size\n");
270 			break;
271 		}
272 		case Opt_errors:
273 		{
274 			char *errors = args[0].from;
275 			if (!errors || !*errors)
276 				goto cleanup;
277 			if (!strcmp(errors, "continue")) {
278 				*flag &= ~JFS_ERR_REMOUNT_RO;
279 				*flag &= ~JFS_ERR_PANIC;
280 				*flag |= JFS_ERR_CONTINUE;
281 			} else if (!strcmp(errors, "remount-ro")) {
282 				*flag &= ~JFS_ERR_CONTINUE;
283 				*flag &= ~JFS_ERR_PANIC;
284 				*flag |= JFS_ERR_REMOUNT_RO;
285 			} else if (!strcmp(errors, "panic")) {
286 				*flag &= ~JFS_ERR_CONTINUE;
287 				*flag &= ~JFS_ERR_REMOUNT_RO;
288 				*flag |= JFS_ERR_PANIC;
289 			} else {
290 				printk(KERN_ERR
291 				       "JFS: %s is an invalid error handler\n",
292 				       errors);
293 				goto cleanup;
294 			}
295 			break;
296 		}
297 
298 #ifdef CONFIG_QUOTA
299 		case Opt_quota:
300 		case Opt_usrquota:
301 			*flag |= JFS_USRQUOTA;
302 			break;
303 		case Opt_grpquota:
304 			*flag |= JFS_GRPQUOTA;
305 			break;
306 #else
307 		case Opt_usrquota:
308 		case Opt_grpquota:
309 		case Opt_quota:
310 			printk(KERN_ERR
311 			       "JFS: quota operations not supported\n");
312 			break;
313 #endif
314 		case Opt_uid:
315 		{
316 			char *uid = args[0].from;
317 			sbi->uid = simple_strtoul(uid, &uid, 0);
318 			break;
319 		}
320 		case Opt_gid:
321 		{
322 			char *gid = args[0].from;
323 			sbi->gid = simple_strtoul(gid, &gid, 0);
324 			break;
325 		}
326 		case Opt_umask:
327 		{
328 			char *umask = args[0].from;
329 			sbi->umask = simple_strtoul(umask, &umask, 8);
330 			if (sbi->umask & ~0777) {
331 				printk(KERN_ERR
332 				       "JFS: Invalid value of umask\n");
333 				goto cleanup;
334 			}
335 			break;
336 		}
337 		default:
338 			printk("jfs: Unrecognized mount option \"%s\" "
339 					" or missing value\n", p);
340 			goto cleanup;
341 		}
342 	}
343 
344 	if (nls_map != (void *) -1) {
345 		/* Discard old (if remount) */
346 		unload_nls(sbi->nls_tab);
347 		sbi->nls_tab = nls_map;
348 	}
349 	return 1;
350 
351 cleanup:
352 	if (nls_map && nls_map != (void *) -1)
353 		unload_nls(nls_map);
354 	return 0;
355 }
356 
357 static int jfs_remount(struct super_block *sb, int *flags, char *data)
358 {
359 	s64 newLVSize = 0;
360 	int rc = 0;
361 	int flag = JFS_SBI(sb)->flag;
362 	int ret;
363 
364 	if (!parse_options(data, sb, &newLVSize, &flag)) {
365 		return -EINVAL;
366 	}
367 
368 	if (newLVSize) {
369 		if (sb->s_flags & MS_RDONLY) {
370 			printk(KERN_ERR
371 		  "JFS: resize requires volume to be mounted read-write\n");
372 			return -EROFS;
373 		}
374 		rc = jfs_extendfs(sb, newLVSize, 0);
375 		if (rc)
376 			return rc;
377 	}
378 
379 	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
380 		/*
381 		 * Invalidate any previously read metadata.  fsck may have
382 		 * changed the on-disk data since we mounted r/o
383 		 */
384 		truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
385 
386 		JFS_SBI(sb)->flag = flag;
387 		ret = jfs_mount_rw(sb, 1);
388 
389 		/* mark the fs r/w for quota activity */
390 		sb->s_flags &= ~MS_RDONLY;
391 
392 		dquot_resume(sb, -1);
393 		return ret;
394 	}
395 	if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
396 		rc = dquot_suspend(sb, -1);
397 		if (rc < 0) {
398 			return rc;
399 		}
400 		rc = jfs_umount_rw(sb);
401 		JFS_SBI(sb)->flag = flag;
402 		return rc;
403 	}
404 	if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
405 		if (!(sb->s_flags & MS_RDONLY)) {
406 			rc = jfs_umount_rw(sb);
407 			if (rc)
408 				return rc;
409 
410 			JFS_SBI(sb)->flag = flag;
411 			ret = jfs_mount_rw(sb, 1);
412 			return ret;
413 		}
414 	JFS_SBI(sb)->flag = flag;
415 
416 	return 0;
417 }
418 
419 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
420 {
421 	struct jfs_sb_info *sbi;
422 	struct inode *inode;
423 	int rc;
424 	s64 newLVSize = 0;
425 	int flag, ret = -EINVAL;
426 
427 	jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
428 
429 	if (!new_valid_dev(sb->s_bdev->bd_dev))
430 		return -EOVERFLOW;
431 
432 	sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
433 	if (!sbi)
434 		return -ENOMEM;
435 
436 	sb->s_fs_info = sbi;
437 	sbi->sb = sb;
438 	sbi->uid = sbi->gid = sbi->umask = -1;
439 
440 	/* initialize the mount flag and determine the default error handler */
441 	flag = JFS_ERR_REMOUNT_RO;
442 
443 	if (!parse_options((char *) data, sb, &newLVSize, &flag))
444 		goto out_kfree;
445 	sbi->flag = flag;
446 
447 #ifdef CONFIG_JFS_POSIX_ACL
448 	sb->s_flags |= MS_POSIXACL;
449 #endif
450 
451 	if (newLVSize) {
452 		printk(KERN_ERR "resize option for remount only\n");
453 		goto out_kfree;
454 	}
455 
456 	/*
457 	 * Initialize blocksize to 4K.
458 	 */
459 	sb_set_blocksize(sb, PSIZE);
460 
461 	/*
462 	 * Set method vectors.
463 	 */
464 	sb->s_op = &jfs_super_operations;
465 	sb->s_export_op = &jfs_export_operations;
466 #ifdef CONFIG_QUOTA
467 	sb->dq_op = &dquot_operations;
468 	sb->s_qcop = &dquot_quotactl_ops;
469 #endif
470 
471 	/*
472 	 * Initialize direct-mapping inode/address-space
473 	 */
474 	inode = new_inode(sb);
475 	if (inode == NULL) {
476 		ret = -ENOMEM;
477 		goto out_unload;
478 	}
479 	inode->i_ino = 0;
480 	inode->i_nlink = 1;
481 	inode->i_size = sb->s_bdev->bd_inode->i_size;
482 	inode->i_mapping->a_ops = &jfs_metapage_aops;
483 	insert_inode_hash(inode);
484 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
485 
486 	sbi->direct_inode = inode;
487 
488 	rc = jfs_mount(sb);
489 	if (rc) {
490 		if (!silent) {
491 			jfs_err("jfs_mount failed w/return code = %d", rc);
492 		}
493 		goto out_mount_failed;
494 	}
495 	if (sb->s_flags & MS_RDONLY)
496 		sbi->log = NULL;
497 	else {
498 		rc = jfs_mount_rw(sb, 0);
499 		if (rc) {
500 			if (!silent) {
501 				jfs_err("jfs_mount_rw failed, return code = %d",
502 					rc);
503 			}
504 			goto out_no_rw;
505 		}
506 	}
507 
508 	sb->s_magic = JFS_SUPER_MAGIC;
509 
510 	inode = jfs_iget(sb, ROOT_I);
511 	if (IS_ERR(inode)) {
512 		ret = PTR_ERR(inode);
513 		goto out_no_rw;
514 	}
515 	sb->s_root = d_alloc_root(inode);
516 	if (!sb->s_root)
517 		goto out_no_root;
518 
519 	if (sbi->mntflag & JFS_OS2)
520 		sb->s_root->d_op = &jfs_ci_dentry_operations;
521 
522 	/* logical blocks are represented by 40 bits in pxd_t, etc. */
523 	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
524 #if BITS_PER_LONG == 32
525 	/*
526 	 * Page cache is indexed by long.
527 	 * I would use MAX_LFS_FILESIZE, but it's only half as big
528 	 */
529 	sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
530 #endif
531 	sb->s_time_gran = 1;
532 	return 0;
533 
534 out_no_root:
535 	jfs_err("jfs_read_super: get root dentry failed");
536 	iput(inode);
537 
538 out_no_rw:
539 	rc = jfs_umount(sb);
540 	if (rc) {
541 		jfs_err("jfs_umount failed with return code %d", rc);
542 	}
543 out_mount_failed:
544 	filemap_write_and_wait(sbi->direct_inode->i_mapping);
545 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
546 	make_bad_inode(sbi->direct_inode);
547 	iput(sbi->direct_inode);
548 	sbi->direct_inode = NULL;
549 out_unload:
550 	if (sbi->nls_tab)
551 		unload_nls(sbi->nls_tab);
552 out_kfree:
553 	kfree(sbi);
554 	return ret;
555 }
556 
557 static int jfs_freeze(struct super_block *sb)
558 {
559 	struct jfs_sb_info *sbi = JFS_SBI(sb);
560 	struct jfs_log *log = sbi->log;
561 
562 	if (!(sb->s_flags & MS_RDONLY)) {
563 		txQuiesce(sb);
564 		lmLogShutdown(log);
565 		updateSuper(sb, FM_CLEAN);
566 	}
567 	return 0;
568 }
569 
570 static int jfs_unfreeze(struct super_block *sb)
571 {
572 	struct jfs_sb_info *sbi = JFS_SBI(sb);
573 	struct jfs_log *log = sbi->log;
574 	int rc = 0;
575 
576 	if (!(sb->s_flags & MS_RDONLY)) {
577 		updateSuper(sb, FM_MOUNT);
578 		if ((rc = lmLogInit(log)))
579 			jfs_err("jfs_unlock failed with return code %d", rc);
580 		else
581 			txResume(sb);
582 	}
583 	return 0;
584 }
585 
586 static struct dentry *jfs_do_mount(struct file_system_type *fs_type,
587 	int flags, const char *dev_name, void *data)
588 {
589 	return mount_bdev(fs_type, flags, dev_name, data, jfs_fill_super);
590 }
591 
592 static int jfs_sync_fs(struct super_block *sb, int wait)
593 {
594 	struct jfs_log *log = JFS_SBI(sb)->log;
595 
596 	/* log == NULL indicates read-only mount */
597 	if (log) {
598 		jfs_flush_journal(log, wait);
599 		jfs_syncpt(log, 0);
600 	}
601 
602 	return 0;
603 }
604 
605 static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
606 {
607 	struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);
608 
609 	if (sbi->uid != -1)
610 		seq_printf(seq, ",uid=%d", sbi->uid);
611 	if (sbi->gid != -1)
612 		seq_printf(seq, ",gid=%d", sbi->gid);
613 	if (sbi->umask != -1)
614 		seq_printf(seq, ",umask=%03o", sbi->umask);
615 	if (sbi->flag & JFS_NOINTEGRITY)
616 		seq_puts(seq, ",nointegrity");
617 	if (sbi->nls_tab)
618 		seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
619 	if (sbi->flag & JFS_ERR_CONTINUE)
620 		seq_printf(seq, ",errors=continue");
621 	if (sbi->flag & JFS_ERR_PANIC)
622 		seq_printf(seq, ",errors=panic");
623 
624 #ifdef CONFIG_QUOTA
625 	if (sbi->flag & JFS_USRQUOTA)
626 		seq_puts(seq, ",usrquota");
627 
628 	if (sbi->flag & JFS_GRPQUOTA)
629 		seq_puts(seq, ",grpquota");
630 #endif
631 
632 	return 0;
633 }
634 
635 #ifdef CONFIG_QUOTA
636 
637 /* Read data from quotafile - avoid pagecache and such because we cannot afford
638  * acquiring the locks... As quota files are never truncated and quota code
639  * itself serializes the operations (and noone else should touch the files)
640  * we don't have to be afraid of races */
641 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
642 			      size_t len, loff_t off)
643 {
644 	struct inode *inode = sb_dqopt(sb)->files[type];
645 	sector_t blk = off >> sb->s_blocksize_bits;
646 	int err = 0;
647 	int offset = off & (sb->s_blocksize - 1);
648 	int tocopy;
649 	size_t toread;
650 	struct buffer_head tmp_bh;
651 	struct buffer_head *bh;
652 	loff_t i_size = i_size_read(inode);
653 
654 	if (off > i_size)
655 		return 0;
656 	if (off+len > i_size)
657 		len = i_size-off;
658 	toread = len;
659 	while (toread > 0) {
660 		tocopy = sb->s_blocksize - offset < toread ?
661 				sb->s_blocksize - offset : toread;
662 
663 		tmp_bh.b_state = 0;
664 		tmp_bh.b_size = 1 << inode->i_blkbits;
665 		err = jfs_get_block(inode, blk, &tmp_bh, 0);
666 		if (err)
667 			return err;
668 		if (!buffer_mapped(&tmp_bh))	/* A hole? */
669 			memset(data, 0, tocopy);
670 		else {
671 			bh = sb_bread(sb, tmp_bh.b_blocknr);
672 			if (!bh)
673 				return -EIO;
674 			memcpy(data, bh->b_data+offset, tocopy);
675 			brelse(bh);
676 		}
677 		offset = 0;
678 		toread -= tocopy;
679 		data += tocopy;
680 		blk++;
681 	}
682 	return len;
683 }
684 
685 /* Write to quotafile */
686 static ssize_t jfs_quota_write(struct super_block *sb, int type,
687 			       const char *data, size_t len, loff_t off)
688 {
689 	struct inode *inode = sb_dqopt(sb)->files[type];
690 	sector_t blk = off >> sb->s_blocksize_bits;
691 	int err = 0;
692 	int offset = off & (sb->s_blocksize - 1);
693 	int tocopy;
694 	size_t towrite = len;
695 	struct buffer_head tmp_bh;
696 	struct buffer_head *bh;
697 
698 	mutex_lock(&inode->i_mutex);
699 	while (towrite > 0) {
700 		tocopy = sb->s_blocksize - offset < towrite ?
701 				sb->s_blocksize - offset : towrite;
702 
703 		tmp_bh.b_state = 0;
704 		tmp_bh.b_size = 1 << inode->i_blkbits;
705 		err = jfs_get_block(inode, blk, &tmp_bh, 1);
706 		if (err)
707 			goto out;
708 		if (offset || tocopy != sb->s_blocksize)
709 			bh = sb_bread(sb, tmp_bh.b_blocknr);
710 		else
711 			bh = sb_getblk(sb, tmp_bh.b_blocknr);
712 		if (!bh) {
713 			err = -EIO;
714 			goto out;
715 		}
716 		lock_buffer(bh);
717 		memcpy(bh->b_data+offset, data, tocopy);
718 		flush_dcache_page(bh->b_page);
719 		set_buffer_uptodate(bh);
720 		mark_buffer_dirty(bh);
721 		unlock_buffer(bh);
722 		brelse(bh);
723 		offset = 0;
724 		towrite -= tocopy;
725 		data += tocopy;
726 		blk++;
727 	}
728 out:
729 	if (len == towrite) {
730 		mutex_unlock(&inode->i_mutex);
731 		return err;
732 	}
733 	if (inode->i_size < off+len-towrite)
734 		i_size_write(inode, off+len-towrite);
735 	inode->i_version++;
736 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
737 	mark_inode_dirty(inode);
738 	mutex_unlock(&inode->i_mutex);
739 	return len - towrite;
740 }
741 
742 #endif
743 
744 static const struct super_operations jfs_super_operations = {
745 	.alloc_inode	= jfs_alloc_inode,
746 	.destroy_inode	= jfs_destroy_inode,
747 	.dirty_inode	= jfs_dirty_inode,
748 	.write_inode	= jfs_write_inode,
749 	.evict_inode	= jfs_evict_inode,
750 	.put_super	= jfs_put_super,
751 	.sync_fs	= jfs_sync_fs,
752 	.freeze_fs	= jfs_freeze,
753 	.unfreeze_fs	= jfs_unfreeze,
754 	.statfs		= jfs_statfs,
755 	.remount_fs	= jfs_remount,
756 	.show_options	= jfs_show_options,
757 #ifdef CONFIG_QUOTA
758 	.quota_read	= jfs_quota_read,
759 	.quota_write	= jfs_quota_write,
760 #endif
761 };
762 
763 static const struct export_operations jfs_export_operations = {
764 	.fh_to_dentry	= jfs_fh_to_dentry,
765 	.fh_to_parent	= jfs_fh_to_parent,
766 	.get_parent	= jfs_get_parent,
767 };
768 
769 static struct file_system_type jfs_fs_type = {
770 	.owner		= THIS_MODULE,
771 	.name		= "jfs",
772 	.mount		= jfs_do_mount,
773 	.kill_sb	= kill_block_super,
774 	.fs_flags	= FS_REQUIRES_DEV,
775 };
776 
777 static void init_once(void *foo)
778 {
779 	struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
780 
781 	memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
782 	INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
783 	init_rwsem(&jfs_ip->rdwrlock);
784 	mutex_init(&jfs_ip->commit_mutex);
785 	init_rwsem(&jfs_ip->xattr_sem);
786 	spin_lock_init(&jfs_ip->ag_lock);
787 	jfs_ip->active_ag = -1;
788 	inode_init_once(&jfs_ip->vfs_inode);
789 }
790 
791 static int __init init_jfs_fs(void)
792 {
793 	int i;
794 	int rc;
795 
796 	jfs_inode_cachep =
797 	    kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
798 			    SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
799 			    init_once);
800 	if (jfs_inode_cachep == NULL)
801 		return -ENOMEM;
802 
803 	/*
804 	 * Metapage initialization
805 	 */
806 	rc = metapage_init();
807 	if (rc) {
808 		jfs_err("metapage_init failed w/rc = %d", rc);
809 		goto free_slab;
810 	}
811 
812 	/*
813 	 * Transaction Manager initialization
814 	 */
815 	rc = txInit();
816 	if (rc) {
817 		jfs_err("txInit failed w/rc = %d", rc);
818 		goto free_metapage;
819 	}
820 
821 	/*
822 	 * I/O completion thread (endio)
823 	 */
824 	jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
825 	if (IS_ERR(jfsIOthread)) {
826 		rc = PTR_ERR(jfsIOthread);
827 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
828 		goto end_txmngr;
829 	}
830 
831 	if (commit_threads < 1)
832 		commit_threads = num_online_cpus();
833 	if (commit_threads > MAX_COMMIT_THREADS)
834 		commit_threads = MAX_COMMIT_THREADS;
835 
836 	for (i = 0; i < commit_threads; i++) {
837 		jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
838 		if (IS_ERR(jfsCommitThread[i])) {
839 			rc = PTR_ERR(jfsCommitThread[i]);
840 			jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
841 			commit_threads = i;
842 			goto kill_committask;
843 		}
844 	}
845 
846 	jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
847 	if (IS_ERR(jfsSyncThread)) {
848 		rc = PTR_ERR(jfsSyncThread);
849 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
850 		goto kill_committask;
851 	}
852 
853 #ifdef PROC_FS_JFS
854 	jfs_proc_init();
855 #endif
856 
857 	return register_filesystem(&jfs_fs_type);
858 
859 kill_committask:
860 	for (i = 0; i < commit_threads; i++)
861 		kthread_stop(jfsCommitThread[i]);
862 	kthread_stop(jfsIOthread);
863 end_txmngr:
864 	txExit();
865 free_metapage:
866 	metapage_exit();
867 free_slab:
868 	kmem_cache_destroy(jfs_inode_cachep);
869 	return rc;
870 }
871 
872 static void __exit exit_jfs_fs(void)
873 {
874 	int i;
875 
876 	jfs_info("exit_jfs_fs called");
877 
878 	txExit();
879 	metapage_exit();
880 
881 	kthread_stop(jfsIOthread);
882 	for (i = 0; i < commit_threads; i++)
883 		kthread_stop(jfsCommitThread[i]);
884 	kthread_stop(jfsSyncThread);
885 #ifdef PROC_FS_JFS
886 	jfs_proc_clean();
887 #endif
888 	unregister_filesystem(&jfs_fs_type);
889 	kmem_cache_destroy(jfs_inode_cachep);
890 }
891 
892 module_init(init_jfs_fs)
893 module_exit(exit_jfs_fs)
894