xref: /openbmc/linux/fs/jfs/super.c (revision b6dcefde)
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 <asm/uaccess.h>
34 #include <linux/seq_file.h>
35 #include <linux/smp_lock.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 	lock_kernel();
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 	unlock_kernel();
190 }
191 
192 enum {
193 	Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
194 	Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
195 	Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
196 };
197 
198 static const match_table_t tokens = {
199 	{Opt_integrity, "integrity"},
200 	{Opt_nointegrity, "nointegrity"},
201 	{Opt_iocharset, "iocharset=%s"},
202 	{Opt_resize, "resize=%u"},
203 	{Opt_resize_nosize, "resize"},
204 	{Opt_errors, "errors=%s"},
205 	{Opt_ignore, "noquota"},
206 	{Opt_ignore, "quota"},
207 	{Opt_usrquota, "usrquota"},
208 	{Opt_grpquota, "grpquota"},
209 	{Opt_uid, "uid=%u"},
210 	{Opt_gid, "gid=%u"},
211 	{Opt_umask, "umask=%u"},
212 	{Opt_err, NULL}
213 };
214 
215 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
216 			 int *flag)
217 {
218 	void *nls_map = (void *)-1;	/* -1: no change;  NULL: none */
219 	char *p;
220 	struct jfs_sb_info *sbi = JFS_SBI(sb);
221 
222 	*newLVSize = 0;
223 
224 	if (!options)
225 		return 1;
226 
227 	while ((p = strsep(&options, ",")) != NULL) {
228 		substring_t args[MAX_OPT_ARGS];
229 		int token;
230 		if (!*p)
231 			continue;
232 
233 		token = match_token(p, tokens, args);
234 		switch (token) {
235 		case Opt_integrity:
236 			*flag &= ~JFS_NOINTEGRITY;
237 			break;
238 		case Opt_nointegrity:
239 			*flag |= JFS_NOINTEGRITY;
240 			break;
241 		case Opt_ignore:
242 			/* Silently ignore the quota options */
243 			/* Don't do anything ;-) */
244 			break;
245 		case Opt_iocharset:
246 			if (nls_map && nls_map != (void *) -1)
247 				unload_nls(nls_map);
248 			if (!strcmp(args[0].from, "none"))
249 				nls_map = NULL;
250 			else {
251 				nls_map = load_nls(args[0].from);
252 				if (!nls_map) {
253 					printk(KERN_ERR
254 					       "JFS: charset not found\n");
255 					goto cleanup;
256 				}
257 			}
258 			break;
259 		case Opt_resize:
260 		{
261 			char *resize = args[0].from;
262 			*newLVSize = simple_strtoull(resize, &resize, 0);
263 			break;
264 		}
265 		case Opt_resize_nosize:
266 		{
267 			*newLVSize = sb->s_bdev->bd_inode->i_size >>
268 				sb->s_blocksize_bits;
269 			if (*newLVSize == 0)
270 				printk(KERN_ERR
271 				       "JFS: Cannot determine volume size\n");
272 			break;
273 		}
274 		case Opt_errors:
275 		{
276 			char *errors = args[0].from;
277 			if (!errors || !*errors)
278 				goto cleanup;
279 			if (!strcmp(errors, "continue")) {
280 				*flag &= ~JFS_ERR_REMOUNT_RO;
281 				*flag &= ~JFS_ERR_PANIC;
282 				*flag |= JFS_ERR_CONTINUE;
283 			} else if (!strcmp(errors, "remount-ro")) {
284 				*flag &= ~JFS_ERR_CONTINUE;
285 				*flag &= ~JFS_ERR_PANIC;
286 				*flag |= JFS_ERR_REMOUNT_RO;
287 			} else if (!strcmp(errors, "panic")) {
288 				*flag &= ~JFS_ERR_CONTINUE;
289 				*flag &= ~JFS_ERR_REMOUNT_RO;
290 				*flag |= JFS_ERR_PANIC;
291 			} else {
292 				printk(KERN_ERR
293 				       "JFS: %s is an invalid error handler\n",
294 				       errors);
295 				goto cleanup;
296 			}
297 			break;
298 		}
299 
300 #ifdef CONFIG_QUOTA
301 		case Opt_quota:
302 		case Opt_usrquota:
303 			*flag |= JFS_USRQUOTA;
304 			break;
305 		case Opt_grpquota:
306 			*flag |= JFS_GRPQUOTA;
307 			break;
308 #else
309 		case Opt_usrquota:
310 		case Opt_grpquota:
311 		case Opt_quota:
312 			printk(KERN_ERR
313 			       "JFS: quota operations not supported\n");
314 			break;
315 #endif
316 		case Opt_uid:
317 		{
318 			char *uid = args[0].from;
319 			sbi->uid = simple_strtoul(uid, &uid, 0);
320 			break;
321 		}
322 		case Opt_gid:
323 		{
324 			char *gid = args[0].from;
325 			sbi->gid = simple_strtoul(gid, &gid, 0);
326 			break;
327 		}
328 		case Opt_umask:
329 		{
330 			char *umask = args[0].from;
331 			sbi->umask = simple_strtoul(umask, &umask, 8);
332 			if (sbi->umask & ~0777) {
333 				printk(KERN_ERR
334 				       "JFS: Invalid value of umask\n");
335 				goto cleanup;
336 			}
337 			break;
338 		}
339 		default:
340 			printk("jfs: Unrecognized mount option \"%s\" "
341 					" or missing value\n", p);
342 			goto cleanup;
343 		}
344 	}
345 
346 	if (nls_map != (void *) -1) {
347 		/* Discard old (if remount) */
348 		unload_nls(sbi->nls_tab);
349 		sbi->nls_tab = nls_map;
350 	}
351 	return 1;
352 
353 cleanup:
354 	if (nls_map && nls_map != (void *) -1)
355 		unload_nls(nls_map);
356 	return 0;
357 }
358 
359 static int jfs_remount(struct super_block *sb, int *flags, char *data)
360 {
361 	s64 newLVSize = 0;
362 	int rc = 0;
363 	int flag = JFS_SBI(sb)->flag;
364 	int ret;
365 
366 	if (!parse_options(data, sb, &newLVSize, &flag)) {
367 		return -EINVAL;
368 	}
369 	lock_kernel();
370 	if (newLVSize) {
371 		if (sb->s_flags & MS_RDONLY) {
372 			printk(KERN_ERR
373 		  "JFS: resize requires volume to be mounted read-write\n");
374 			unlock_kernel();
375 			return -EROFS;
376 		}
377 		rc = jfs_extendfs(sb, newLVSize, 0);
378 		if (rc) {
379 			unlock_kernel();
380 			return rc;
381 		}
382 	}
383 
384 	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
385 		/*
386 		 * Invalidate any previously read metadata.  fsck may have
387 		 * changed the on-disk data since we mounted r/o
388 		 */
389 		truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
390 
391 		JFS_SBI(sb)->flag = flag;
392 		ret = jfs_mount_rw(sb, 1);
393 		unlock_kernel();
394 		return ret;
395 	}
396 	if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
397 		rc = jfs_umount_rw(sb);
398 		JFS_SBI(sb)->flag = flag;
399 		unlock_kernel();
400 		return rc;
401 	}
402 	if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
403 		if (!(sb->s_flags & MS_RDONLY)) {
404 			rc = jfs_umount_rw(sb);
405 			if (rc) {
406 				unlock_kernel();
407 				return rc;
408 			}
409 			JFS_SBI(sb)->flag = flag;
410 			ret = jfs_mount_rw(sb, 1);
411 			unlock_kernel();
412 			return ret;
413 		}
414 	JFS_SBI(sb)->flag = flag;
415 
416 	unlock_kernel();
417 	return 0;
418 }
419 
420 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
421 {
422 	struct jfs_sb_info *sbi;
423 	struct inode *inode;
424 	int rc;
425 	s64 newLVSize = 0;
426 	int flag, ret = -EINVAL;
427 
428 	jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
429 
430 	if (!new_valid_dev(sb->s_bdev->bd_dev))
431 		return -EOVERFLOW;
432 
433 	sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
434 	if (!sbi)
435 		return -ENOMEM;
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 		kfree(sbi);
445 		return -EINVAL;
446 	}
447 	sbi->flag = flag;
448 
449 #ifdef CONFIG_JFS_POSIX_ACL
450 	sb->s_flags |= MS_POSIXACL;
451 #endif
452 
453 	if (newLVSize) {
454 		printk(KERN_ERR "resize option for remount only\n");
455 		return -EINVAL;
456 	}
457 
458 	/*
459 	 * Initialize blocksize to 4K.
460 	 */
461 	sb_set_blocksize(sb, PSIZE);
462 
463 	/*
464 	 * Set method vectors.
465 	 */
466 	sb->s_op = &jfs_super_operations;
467 	sb->s_export_op = &jfs_export_operations;
468 
469 	/*
470 	 * Initialize direct-mapping inode/address-space
471 	 */
472 	inode = new_inode(sb);
473 	if (inode == NULL) {
474 		ret = -ENOMEM;
475 		goto out_kfree;
476 	}
477 	inode->i_ino = 0;
478 	inode->i_nlink = 1;
479 	inode->i_size = sb->s_bdev->bd_inode->i_size;
480 	inode->i_mapping->a_ops = &jfs_metapage_aops;
481 	insert_inode_hash(inode);
482 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
483 
484 	sbi->direct_inode = inode;
485 
486 	rc = jfs_mount(sb);
487 	if (rc) {
488 		if (!silent) {
489 			jfs_err("jfs_mount failed w/return code = %d", rc);
490 		}
491 		goto out_mount_failed;
492 	}
493 	if (sb->s_flags & MS_RDONLY)
494 		sbi->log = NULL;
495 	else {
496 		rc = jfs_mount_rw(sb, 0);
497 		if (rc) {
498 			if (!silent) {
499 				jfs_err("jfs_mount_rw failed, return code = %d",
500 					rc);
501 			}
502 			goto out_no_rw;
503 		}
504 	}
505 
506 	sb->s_magic = JFS_SUPER_MAGIC;
507 
508 	inode = jfs_iget(sb, ROOT_I);
509 	if (IS_ERR(inode)) {
510 		ret = PTR_ERR(inode);
511 		goto out_no_rw;
512 	}
513 	sb->s_root = d_alloc_root(inode);
514 	if (!sb->s_root)
515 		goto out_no_root;
516 
517 	if (sbi->mntflag & JFS_OS2)
518 		sb->s_root->d_op = &jfs_ci_dentry_operations;
519 
520 	/* logical blocks are represented by 40 bits in pxd_t, etc. */
521 	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
522 #if BITS_PER_LONG == 32
523 	/*
524 	 * Page cache is indexed by long.
525 	 * I would use MAX_LFS_FILESIZE, but it's only half as big
526 	 */
527 	sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
528 #endif
529 	sb->s_time_gran = 1;
530 	return 0;
531 
532 out_no_root:
533 	jfs_err("jfs_read_super: get root dentry failed");
534 	iput(inode);
535 
536 out_no_rw:
537 	rc = jfs_umount(sb);
538 	if (rc) {
539 		jfs_err("jfs_umount failed with return code %d", rc);
540 	}
541 out_mount_failed:
542 	filemap_write_and_wait(sbi->direct_inode->i_mapping);
543 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
544 	make_bad_inode(sbi->direct_inode);
545 	iput(sbi->direct_inode);
546 	sbi->direct_inode = NULL;
547 out_kfree:
548 	if (sbi->nls_tab)
549 		unload_nls(sbi->nls_tab);
550 	kfree(sbi);
551 	return ret;
552 }
553 
554 static int jfs_freeze(struct super_block *sb)
555 {
556 	struct jfs_sb_info *sbi = JFS_SBI(sb);
557 	struct jfs_log *log = sbi->log;
558 
559 	if (!(sb->s_flags & MS_RDONLY)) {
560 		txQuiesce(sb);
561 		lmLogShutdown(log);
562 		updateSuper(sb, FM_CLEAN);
563 	}
564 	return 0;
565 }
566 
567 static int jfs_unfreeze(struct super_block *sb)
568 {
569 	struct jfs_sb_info *sbi = JFS_SBI(sb);
570 	struct jfs_log *log = sbi->log;
571 	int rc = 0;
572 
573 	if (!(sb->s_flags & MS_RDONLY)) {
574 		updateSuper(sb, FM_MOUNT);
575 		if ((rc = lmLogInit(log)))
576 			jfs_err("jfs_unlock failed with return code %d", rc);
577 		else
578 			txResume(sb);
579 	}
580 	return 0;
581 }
582 
583 static int jfs_get_sb(struct file_system_type *fs_type,
584 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
585 {
586 	return get_sb_bdev(fs_type, flags, dev_name, data, jfs_fill_super,
587 			   mnt);
588 }
589 
590 static int jfs_sync_fs(struct super_block *sb, int wait)
591 {
592 	struct jfs_log *log = JFS_SBI(sb)->log;
593 
594 	/* log == NULL indicates read-only mount */
595 	if (log) {
596 		jfs_flush_journal(log, wait);
597 		jfs_syncpt(log, 0);
598 	}
599 
600 	return 0;
601 }
602 
603 static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
604 {
605 	struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);
606 
607 	if (sbi->uid != -1)
608 		seq_printf(seq, ",uid=%d", sbi->uid);
609 	if (sbi->gid != -1)
610 		seq_printf(seq, ",gid=%d", sbi->gid);
611 	if (sbi->umask != -1)
612 		seq_printf(seq, ",umask=%03o", sbi->umask);
613 	if (sbi->flag & JFS_NOINTEGRITY)
614 		seq_puts(seq, ",nointegrity");
615 	if (sbi->nls_tab)
616 		seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
617 	if (sbi->flag & JFS_ERR_CONTINUE)
618 		seq_printf(seq, ",errors=continue");
619 	if (sbi->flag & JFS_ERR_PANIC)
620 		seq_printf(seq, ",errors=panic");
621 
622 #ifdef CONFIG_QUOTA
623 	if (sbi->flag & JFS_USRQUOTA)
624 		seq_puts(seq, ",usrquota");
625 
626 	if (sbi->flag & JFS_GRPQUOTA)
627 		seq_puts(seq, ",grpquota");
628 #endif
629 
630 	return 0;
631 }
632 
633 #ifdef CONFIG_QUOTA
634 
635 /* Read data from quotafile - avoid pagecache and such because we cannot afford
636  * acquiring the locks... As quota files are never truncated and quota code
637  * itself serializes the operations (and noone else should touch the files)
638  * we don't have to be afraid of races */
639 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
640 			      size_t len, loff_t off)
641 {
642 	struct inode *inode = sb_dqopt(sb)->files[type];
643 	sector_t blk = off >> sb->s_blocksize_bits;
644 	int err = 0;
645 	int offset = off & (sb->s_blocksize - 1);
646 	int tocopy;
647 	size_t toread;
648 	struct buffer_head tmp_bh;
649 	struct buffer_head *bh;
650 	loff_t i_size = i_size_read(inode);
651 
652 	if (off > i_size)
653 		return 0;
654 	if (off+len > i_size)
655 		len = i_size-off;
656 	toread = len;
657 	while (toread > 0) {
658 		tocopy = sb->s_blocksize - offset < toread ?
659 				sb->s_blocksize - offset : toread;
660 
661 		tmp_bh.b_state = 0;
662 		tmp_bh.b_size = 1 << inode->i_blkbits;
663 		err = jfs_get_block(inode, blk, &tmp_bh, 0);
664 		if (err)
665 			return err;
666 		if (!buffer_mapped(&tmp_bh))	/* A hole? */
667 			memset(data, 0, tocopy);
668 		else {
669 			bh = sb_bread(sb, tmp_bh.b_blocknr);
670 			if (!bh)
671 				return -EIO;
672 			memcpy(data, bh->b_data+offset, tocopy);
673 			brelse(bh);
674 		}
675 		offset = 0;
676 		toread -= tocopy;
677 		data += tocopy;
678 		blk++;
679 	}
680 	return len;
681 }
682 
683 /* Write to quotafile */
684 static ssize_t jfs_quota_write(struct super_block *sb, int type,
685 			       const char *data, size_t len, loff_t off)
686 {
687 	struct inode *inode = sb_dqopt(sb)->files[type];
688 	sector_t blk = off >> sb->s_blocksize_bits;
689 	int err = 0;
690 	int offset = off & (sb->s_blocksize - 1);
691 	int tocopy;
692 	size_t towrite = len;
693 	struct buffer_head tmp_bh;
694 	struct buffer_head *bh;
695 
696 	mutex_lock(&inode->i_mutex);
697 	while (towrite > 0) {
698 		tocopy = sb->s_blocksize - offset < towrite ?
699 				sb->s_blocksize - offset : towrite;
700 
701 		tmp_bh.b_state = 0;
702 		tmp_bh.b_size = 1 << inode->i_blkbits;
703 		err = jfs_get_block(inode, blk, &tmp_bh, 1);
704 		if (err)
705 			goto out;
706 		if (offset || tocopy != sb->s_blocksize)
707 			bh = sb_bread(sb, tmp_bh.b_blocknr);
708 		else
709 			bh = sb_getblk(sb, tmp_bh.b_blocknr);
710 		if (!bh) {
711 			err = -EIO;
712 			goto out;
713 		}
714 		lock_buffer(bh);
715 		memcpy(bh->b_data+offset, data, tocopy);
716 		flush_dcache_page(bh->b_page);
717 		set_buffer_uptodate(bh);
718 		mark_buffer_dirty(bh);
719 		unlock_buffer(bh);
720 		brelse(bh);
721 		offset = 0;
722 		towrite -= tocopy;
723 		data += tocopy;
724 		blk++;
725 	}
726 out:
727 	if (len == towrite) {
728 		mutex_unlock(&inode->i_mutex);
729 		return err;
730 	}
731 	if (inode->i_size < off+len-towrite)
732 		i_size_write(inode, off+len-towrite);
733 	inode->i_version++;
734 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
735 	mark_inode_dirty(inode);
736 	mutex_unlock(&inode->i_mutex);
737 	return len - towrite;
738 }
739 
740 #endif
741 
742 static const struct super_operations jfs_super_operations = {
743 	.alloc_inode	= jfs_alloc_inode,
744 	.destroy_inode	= jfs_destroy_inode,
745 	.dirty_inode	= jfs_dirty_inode,
746 	.write_inode	= jfs_write_inode,
747 	.delete_inode	= jfs_delete_inode,
748 	.put_super	= jfs_put_super,
749 	.sync_fs	= jfs_sync_fs,
750 	.freeze_fs	= jfs_freeze,
751 	.unfreeze_fs	= jfs_unfreeze,
752 	.statfs		= jfs_statfs,
753 	.remount_fs	= jfs_remount,
754 	.show_options	= jfs_show_options,
755 #ifdef CONFIG_QUOTA
756 	.quota_read	= jfs_quota_read,
757 	.quota_write	= jfs_quota_write,
758 #endif
759 };
760 
761 static const struct export_operations jfs_export_operations = {
762 	.fh_to_dentry	= jfs_fh_to_dentry,
763 	.fh_to_parent	= jfs_fh_to_parent,
764 	.get_parent	= jfs_get_parent,
765 };
766 
767 static struct file_system_type jfs_fs_type = {
768 	.owner		= THIS_MODULE,
769 	.name		= "jfs",
770 	.get_sb		= jfs_get_sb,
771 	.kill_sb	= kill_block_super,
772 	.fs_flags	= FS_REQUIRES_DEV,
773 };
774 
775 static void init_once(void *foo)
776 {
777 	struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
778 
779 	memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
780 	INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
781 	init_rwsem(&jfs_ip->rdwrlock);
782 	mutex_init(&jfs_ip->commit_mutex);
783 	init_rwsem(&jfs_ip->xattr_sem);
784 	spin_lock_init(&jfs_ip->ag_lock);
785 	jfs_ip->active_ag = -1;
786 	inode_init_once(&jfs_ip->vfs_inode);
787 }
788 
789 static int __init init_jfs_fs(void)
790 {
791 	int i;
792 	int rc;
793 
794 	jfs_inode_cachep =
795 	    kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
796 			    SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
797 			    init_once);
798 	if (jfs_inode_cachep == NULL)
799 		return -ENOMEM;
800 
801 	/*
802 	 * Metapage initialization
803 	 */
804 	rc = metapage_init();
805 	if (rc) {
806 		jfs_err("metapage_init failed w/rc = %d", rc);
807 		goto free_slab;
808 	}
809 
810 	/*
811 	 * Transaction Manager initialization
812 	 */
813 	rc = txInit();
814 	if (rc) {
815 		jfs_err("txInit failed w/rc = %d", rc);
816 		goto free_metapage;
817 	}
818 
819 	/*
820 	 * I/O completion thread (endio)
821 	 */
822 	jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
823 	if (IS_ERR(jfsIOthread)) {
824 		rc = PTR_ERR(jfsIOthread);
825 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
826 		goto end_txmngr;
827 	}
828 
829 	if (commit_threads < 1)
830 		commit_threads = num_online_cpus();
831 	if (commit_threads > MAX_COMMIT_THREADS)
832 		commit_threads = MAX_COMMIT_THREADS;
833 
834 	for (i = 0; i < commit_threads; i++) {
835 		jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
836 		if (IS_ERR(jfsCommitThread[i])) {
837 			rc = PTR_ERR(jfsCommitThread[i]);
838 			jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
839 			commit_threads = i;
840 			goto kill_committask;
841 		}
842 	}
843 
844 	jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
845 	if (IS_ERR(jfsSyncThread)) {
846 		rc = PTR_ERR(jfsSyncThread);
847 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
848 		goto kill_committask;
849 	}
850 
851 #ifdef PROC_FS_JFS
852 	jfs_proc_init();
853 #endif
854 
855 	return register_filesystem(&jfs_fs_type);
856 
857 kill_committask:
858 	for (i = 0; i < commit_threads; i++)
859 		kthread_stop(jfsCommitThread[i]);
860 	kthread_stop(jfsIOthread);
861 end_txmngr:
862 	txExit();
863 free_metapage:
864 	metapage_exit();
865 free_slab:
866 	kmem_cache_destroy(jfs_inode_cachep);
867 	return rc;
868 }
869 
870 static void __exit exit_jfs_fs(void)
871 {
872 	int i;
873 
874 	jfs_info("exit_jfs_fs called");
875 
876 	txExit();
877 	metapage_exit();
878 
879 	kthread_stop(jfsIOthread);
880 	for (i = 0; i < commit_threads; i++)
881 		kthread_stop(jfsCommitThread[i]);
882 	kthread_stop(jfsSyncThread);
883 #ifdef PROC_FS_JFS
884 	jfs_proc_clean();
885 #endif
886 	unregister_filesystem(&jfs_fs_type);
887 	kmem_cache_destroy(jfs_inode_cachep);
888 }
889 
890 module_init(init_jfs_fs)
891 module_exit(exit_jfs_fs)
892