xref: /openbmc/linux/fs/jfs/super.c (revision d5532ee7)
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/smp_lock.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 * function, ...)
96 {
97 	static char error_buf[256];
98 	va_list args;
99 
100 	va_start(args, function);
101 	vsnprintf(error_buf, sizeof(error_buf), function, args);
102 	va_end(args);
103 
104 	printk(KERN_ERR "ERROR: (device %s): %s\n", sb->s_id, error_buf);
105 
106 	jfs_handle_error(sb);
107 }
108 
109 static struct inode *jfs_alloc_inode(struct super_block *sb)
110 {
111 	struct jfs_inode_info *jfs_inode;
112 
113 	jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
114 	if (!jfs_inode)
115 		return NULL;
116 	return &jfs_inode->vfs_inode;
117 }
118 
119 static void jfs_destroy_inode(struct inode *inode)
120 {
121 	struct jfs_inode_info *ji = JFS_IP(inode);
122 
123 	BUG_ON(!list_empty(&ji->anon_inode_list));
124 
125 	spin_lock_irq(&ji->ag_lock);
126 	if (ji->active_ag != -1) {
127 		struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
128 		atomic_dec(&bmap->db_active[ji->active_ag]);
129 		ji->active_ag = -1;
130 	}
131 	spin_unlock_irq(&ji->ag_lock);
132 	kmem_cache_free(jfs_inode_cachep, ji);
133 }
134 
135 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
136 {
137 	struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
138 	s64 maxinodes;
139 	struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
140 
141 	jfs_info("In jfs_statfs");
142 	buf->f_type = JFS_SUPER_MAGIC;
143 	buf->f_bsize = sbi->bsize;
144 	buf->f_blocks = sbi->bmap->db_mapsize;
145 	buf->f_bfree = sbi->bmap->db_nfree;
146 	buf->f_bavail = sbi->bmap->db_nfree;
147 	/*
148 	 * If we really return the number of allocated & free inodes, some
149 	 * applications will fail because they won't see enough free inodes.
150 	 * We'll try to calculate some guess as to how may inodes we can
151 	 * really allocate
152 	 *
153 	 * buf->f_files = atomic_read(&imap->im_numinos);
154 	 * buf->f_ffree = atomic_read(&imap->im_numfree);
155 	 */
156 	maxinodes = min((s64) atomic_read(&imap->im_numinos) +
157 			((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
158 			 << L2INOSPEREXT), (s64) 0xffffffffLL);
159 	buf->f_files = maxinodes;
160 	buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
161 				    atomic_read(&imap->im_numfree));
162 	buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
163 	buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
164 					sizeof(sbi->uuid)/2);
165 
166 	buf->f_namelen = JFS_NAME_MAX;
167 	return 0;
168 }
169 
170 static void jfs_put_super(struct super_block *sb)
171 {
172 	struct jfs_sb_info *sbi = JFS_SBI(sb);
173 	int rc;
174 
175 	jfs_info("In jfs_put_super");
176 
177 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
178 
179 	lock_kernel();
180 
181 	rc = jfs_umount(sb);
182 	if (rc)
183 		jfs_err("jfs_umount failed with return code %d", rc);
184 
185 	unload_nls(sbi->nls_tab);
186 
187 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
188 	iput(sbi->direct_inode);
189 
190 	kfree(sbi);
191 
192 	unlock_kernel();
193 }
194 
195 enum {
196 	Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
197 	Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
198 	Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
199 };
200 
201 static const match_table_t tokens = {
202 	{Opt_integrity, "integrity"},
203 	{Opt_nointegrity, "nointegrity"},
204 	{Opt_iocharset, "iocharset=%s"},
205 	{Opt_resize, "resize=%u"},
206 	{Opt_resize_nosize, "resize"},
207 	{Opt_errors, "errors=%s"},
208 	{Opt_ignore, "noquota"},
209 	{Opt_ignore, "quota"},
210 	{Opt_usrquota, "usrquota"},
211 	{Opt_grpquota, "grpquota"},
212 	{Opt_uid, "uid=%u"},
213 	{Opt_gid, "gid=%u"},
214 	{Opt_umask, "umask=%u"},
215 	{Opt_err, NULL}
216 };
217 
218 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
219 			 int *flag)
220 {
221 	void *nls_map = (void *)-1;	/* -1: no change;  NULL: none */
222 	char *p;
223 	struct jfs_sb_info *sbi = JFS_SBI(sb);
224 
225 	*newLVSize = 0;
226 
227 	if (!options)
228 		return 1;
229 
230 	while ((p = strsep(&options, ",")) != NULL) {
231 		substring_t args[MAX_OPT_ARGS];
232 		int token;
233 		if (!*p)
234 			continue;
235 
236 		token = match_token(p, tokens, args);
237 		switch (token) {
238 		case Opt_integrity:
239 			*flag &= ~JFS_NOINTEGRITY;
240 			break;
241 		case Opt_nointegrity:
242 			*flag |= JFS_NOINTEGRITY;
243 			break;
244 		case Opt_ignore:
245 			/* Silently ignore the quota options */
246 			/* Don't do anything ;-) */
247 			break;
248 		case Opt_iocharset:
249 			if (nls_map && nls_map != (void *) -1)
250 				unload_nls(nls_map);
251 			if (!strcmp(args[0].from, "none"))
252 				nls_map = NULL;
253 			else {
254 				nls_map = load_nls(args[0].from);
255 				if (!nls_map) {
256 					printk(KERN_ERR
257 					       "JFS: charset not found\n");
258 					goto cleanup;
259 				}
260 			}
261 			break;
262 		case Opt_resize:
263 		{
264 			char *resize = args[0].from;
265 			*newLVSize = simple_strtoull(resize, &resize, 0);
266 			break;
267 		}
268 		case Opt_resize_nosize:
269 		{
270 			*newLVSize = sb->s_bdev->bd_inode->i_size >>
271 				sb->s_blocksize_bits;
272 			if (*newLVSize == 0)
273 				printk(KERN_ERR
274 				       "JFS: Cannot determine volume size\n");
275 			break;
276 		}
277 		case Opt_errors:
278 		{
279 			char *errors = args[0].from;
280 			if (!errors || !*errors)
281 				goto cleanup;
282 			if (!strcmp(errors, "continue")) {
283 				*flag &= ~JFS_ERR_REMOUNT_RO;
284 				*flag &= ~JFS_ERR_PANIC;
285 				*flag |= JFS_ERR_CONTINUE;
286 			} else if (!strcmp(errors, "remount-ro")) {
287 				*flag &= ~JFS_ERR_CONTINUE;
288 				*flag &= ~JFS_ERR_PANIC;
289 				*flag |= JFS_ERR_REMOUNT_RO;
290 			} else if (!strcmp(errors, "panic")) {
291 				*flag &= ~JFS_ERR_CONTINUE;
292 				*flag &= ~JFS_ERR_REMOUNT_RO;
293 				*flag |= JFS_ERR_PANIC;
294 			} else {
295 				printk(KERN_ERR
296 				       "JFS: %s is an invalid error handler\n",
297 				       errors);
298 				goto cleanup;
299 			}
300 			break;
301 		}
302 
303 #ifdef CONFIG_QUOTA
304 		case Opt_quota:
305 		case Opt_usrquota:
306 			*flag |= JFS_USRQUOTA;
307 			break;
308 		case Opt_grpquota:
309 			*flag |= JFS_GRPQUOTA;
310 			break;
311 #else
312 		case Opt_usrquota:
313 		case Opt_grpquota:
314 		case Opt_quota:
315 			printk(KERN_ERR
316 			       "JFS: quota operations not supported\n");
317 			break;
318 #endif
319 		case Opt_uid:
320 		{
321 			char *uid = args[0].from;
322 			sbi->uid = simple_strtoul(uid, &uid, 0);
323 			break;
324 		}
325 		case Opt_gid:
326 		{
327 			char *gid = args[0].from;
328 			sbi->gid = simple_strtoul(gid, &gid, 0);
329 			break;
330 		}
331 		case Opt_umask:
332 		{
333 			char *umask = args[0].from;
334 			sbi->umask = simple_strtoul(umask, &umask, 8);
335 			if (sbi->umask & ~0777) {
336 				printk(KERN_ERR
337 				       "JFS: Invalid value of umask\n");
338 				goto cleanup;
339 			}
340 			break;
341 		}
342 		default:
343 			printk("jfs: Unrecognized mount option \"%s\" "
344 					" or missing value\n", p);
345 			goto cleanup;
346 		}
347 	}
348 
349 	if (nls_map != (void *) -1) {
350 		/* Discard old (if remount) */
351 		unload_nls(sbi->nls_tab);
352 		sbi->nls_tab = nls_map;
353 	}
354 	return 1;
355 
356 cleanup:
357 	if (nls_map && nls_map != (void *) -1)
358 		unload_nls(nls_map);
359 	return 0;
360 }
361 
362 static int jfs_remount(struct super_block *sb, int *flags, char *data)
363 {
364 	s64 newLVSize = 0;
365 	int rc = 0;
366 	int flag = JFS_SBI(sb)->flag;
367 	int ret;
368 
369 	if (!parse_options(data, sb, &newLVSize, &flag)) {
370 		return -EINVAL;
371 	}
372 	lock_kernel();
373 	if (newLVSize) {
374 		if (sb->s_flags & MS_RDONLY) {
375 			printk(KERN_ERR
376 		  "JFS: resize requires volume to be mounted read-write\n");
377 			unlock_kernel();
378 			return -EROFS;
379 		}
380 		rc = jfs_extendfs(sb, newLVSize, 0);
381 		if (rc) {
382 			unlock_kernel();
383 			return rc;
384 		}
385 	}
386 
387 	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
388 		/*
389 		 * Invalidate any previously read metadata.  fsck may have
390 		 * changed the on-disk data since we mounted r/o
391 		 */
392 		truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
393 
394 		JFS_SBI(sb)->flag = flag;
395 		ret = jfs_mount_rw(sb, 1);
396 
397 		/* mark the fs r/w for quota activity */
398 		sb->s_flags &= ~MS_RDONLY;
399 
400 		unlock_kernel();
401 		dquot_resume(sb, -1);
402 		return ret;
403 	}
404 	if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
405 		rc = dquot_suspend(sb, -1);
406 		if (rc < 0) {
407 			unlock_kernel();
408 			return rc;
409 		}
410 		rc = jfs_umount_rw(sb);
411 		JFS_SBI(sb)->flag = flag;
412 		unlock_kernel();
413 		return rc;
414 	}
415 	if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
416 		if (!(sb->s_flags & MS_RDONLY)) {
417 			rc = jfs_umount_rw(sb);
418 			if (rc) {
419 				unlock_kernel();
420 				return rc;
421 			}
422 			JFS_SBI(sb)->flag = flag;
423 			ret = jfs_mount_rw(sb, 1);
424 			unlock_kernel();
425 			return ret;
426 		}
427 	JFS_SBI(sb)->flag = flag;
428 
429 	unlock_kernel();
430 	return 0;
431 }
432 
433 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
434 {
435 	struct jfs_sb_info *sbi;
436 	struct inode *inode;
437 	int rc;
438 	s64 newLVSize = 0;
439 	int flag, ret = -EINVAL;
440 
441 	jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
442 
443 	if (!new_valid_dev(sb->s_bdev->bd_dev))
444 		return -EOVERFLOW;
445 
446 	sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
447 	if (!sbi)
448 		return -ENOMEM;
449 	sb->s_fs_info = sbi;
450 	sbi->sb = sb;
451 	sbi->uid = sbi->gid = sbi->umask = -1;
452 
453 	/* initialize the mount flag and determine the default error handler */
454 	flag = JFS_ERR_REMOUNT_RO;
455 
456 	if (!parse_options((char *) data, sb, &newLVSize, &flag))
457 		goto out_kfree;
458 	sbi->flag = flag;
459 
460 #ifdef CONFIG_JFS_POSIX_ACL
461 	sb->s_flags |= MS_POSIXACL;
462 #endif
463 
464 	if (newLVSize) {
465 		printk(KERN_ERR "resize option for remount only\n");
466 		goto out_kfree;
467 	}
468 
469 	/*
470 	 * Initialize blocksize to 4K.
471 	 */
472 	sb_set_blocksize(sb, PSIZE);
473 
474 	/*
475 	 * Set method vectors.
476 	 */
477 	sb->s_op = &jfs_super_operations;
478 	sb->s_export_op = &jfs_export_operations;
479 #ifdef CONFIG_QUOTA
480 	sb->dq_op = &dquot_operations;
481 	sb->s_qcop = &dquot_quotactl_ops;
482 #endif
483 
484 	/*
485 	 * Initialize direct-mapping inode/address-space
486 	 */
487 	inode = new_inode(sb);
488 	if (inode == NULL) {
489 		ret = -ENOMEM;
490 		goto out_unload;
491 	}
492 	inode->i_ino = 0;
493 	inode->i_nlink = 1;
494 	inode->i_size = sb->s_bdev->bd_inode->i_size;
495 	inode->i_mapping->a_ops = &jfs_metapage_aops;
496 	insert_inode_hash(inode);
497 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
498 
499 	sbi->direct_inode = inode;
500 
501 	rc = jfs_mount(sb);
502 	if (rc) {
503 		if (!silent) {
504 			jfs_err("jfs_mount failed w/return code = %d", rc);
505 		}
506 		goto out_mount_failed;
507 	}
508 	if (sb->s_flags & MS_RDONLY)
509 		sbi->log = NULL;
510 	else {
511 		rc = jfs_mount_rw(sb, 0);
512 		if (rc) {
513 			if (!silent) {
514 				jfs_err("jfs_mount_rw failed, return code = %d",
515 					rc);
516 			}
517 			goto out_no_rw;
518 		}
519 	}
520 
521 	sb->s_magic = JFS_SUPER_MAGIC;
522 
523 	inode = jfs_iget(sb, ROOT_I);
524 	if (IS_ERR(inode)) {
525 		ret = PTR_ERR(inode);
526 		goto out_no_rw;
527 	}
528 	sb->s_root = d_alloc_root(inode);
529 	if (!sb->s_root)
530 		goto out_no_root;
531 
532 	if (sbi->mntflag & JFS_OS2)
533 		sb->s_root->d_op = &jfs_ci_dentry_operations;
534 
535 	/* logical blocks are represented by 40 bits in pxd_t, etc. */
536 	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
537 #if BITS_PER_LONG == 32
538 	/*
539 	 * Page cache is indexed by long.
540 	 * I would use MAX_LFS_FILESIZE, but it's only half as big
541 	 */
542 	sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
543 #endif
544 	sb->s_time_gran = 1;
545 	return 0;
546 
547 out_no_root:
548 	jfs_err("jfs_read_super: get root dentry failed");
549 	iput(inode);
550 
551 out_no_rw:
552 	rc = jfs_umount(sb);
553 	if (rc) {
554 		jfs_err("jfs_umount failed with return code %d", rc);
555 	}
556 out_mount_failed:
557 	filemap_write_and_wait(sbi->direct_inode->i_mapping);
558 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
559 	make_bad_inode(sbi->direct_inode);
560 	iput(sbi->direct_inode);
561 	sbi->direct_inode = NULL;
562 out_unload:
563 	if (sbi->nls_tab)
564 		unload_nls(sbi->nls_tab);
565 out_kfree:
566 	kfree(sbi);
567 	return ret;
568 }
569 
570 static int jfs_freeze(struct super_block *sb)
571 {
572 	struct jfs_sb_info *sbi = JFS_SBI(sb);
573 	struct jfs_log *log = sbi->log;
574 
575 	if (!(sb->s_flags & MS_RDONLY)) {
576 		txQuiesce(sb);
577 		lmLogShutdown(log);
578 		updateSuper(sb, FM_CLEAN);
579 	}
580 	return 0;
581 }
582 
583 static int jfs_unfreeze(struct super_block *sb)
584 {
585 	struct jfs_sb_info *sbi = JFS_SBI(sb);
586 	struct jfs_log *log = sbi->log;
587 	int rc = 0;
588 
589 	if (!(sb->s_flags & MS_RDONLY)) {
590 		updateSuper(sb, FM_MOUNT);
591 		if ((rc = lmLogInit(log)))
592 			jfs_err("jfs_unlock failed with return code %d", rc);
593 		else
594 			txResume(sb);
595 	}
596 	return 0;
597 }
598 
599 static int jfs_get_sb(struct file_system_type *fs_type,
600 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
601 {
602 	return get_sb_bdev(fs_type, flags, dev_name, data, jfs_fill_super,
603 			   mnt);
604 }
605 
606 static int jfs_sync_fs(struct super_block *sb, int wait)
607 {
608 	struct jfs_log *log = JFS_SBI(sb)->log;
609 
610 	/* log == NULL indicates read-only mount */
611 	if (log) {
612 		jfs_flush_journal(log, wait);
613 		jfs_syncpt(log, 0);
614 	}
615 
616 	return 0;
617 }
618 
619 static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
620 {
621 	struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);
622 
623 	if (sbi->uid != -1)
624 		seq_printf(seq, ",uid=%d", sbi->uid);
625 	if (sbi->gid != -1)
626 		seq_printf(seq, ",gid=%d", sbi->gid);
627 	if (sbi->umask != -1)
628 		seq_printf(seq, ",umask=%03o", sbi->umask);
629 	if (sbi->flag & JFS_NOINTEGRITY)
630 		seq_puts(seq, ",nointegrity");
631 	if (sbi->nls_tab)
632 		seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
633 	if (sbi->flag & JFS_ERR_CONTINUE)
634 		seq_printf(seq, ",errors=continue");
635 	if (sbi->flag & JFS_ERR_PANIC)
636 		seq_printf(seq, ",errors=panic");
637 
638 #ifdef CONFIG_QUOTA
639 	if (sbi->flag & JFS_USRQUOTA)
640 		seq_puts(seq, ",usrquota");
641 
642 	if (sbi->flag & JFS_GRPQUOTA)
643 		seq_puts(seq, ",grpquota");
644 #endif
645 
646 	return 0;
647 }
648 
649 #ifdef CONFIG_QUOTA
650 
651 /* Read data from quotafile - avoid pagecache and such because we cannot afford
652  * acquiring the locks... As quota files are never truncated and quota code
653  * itself serializes the operations (and noone else should touch the files)
654  * we don't have to be afraid of races */
655 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
656 			      size_t len, loff_t off)
657 {
658 	struct inode *inode = sb_dqopt(sb)->files[type];
659 	sector_t blk = off >> sb->s_blocksize_bits;
660 	int err = 0;
661 	int offset = off & (sb->s_blocksize - 1);
662 	int tocopy;
663 	size_t toread;
664 	struct buffer_head tmp_bh;
665 	struct buffer_head *bh;
666 	loff_t i_size = i_size_read(inode);
667 
668 	if (off > i_size)
669 		return 0;
670 	if (off+len > i_size)
671 		len = i_size-off;
672 	toread = len;
673 	while (toread > 0) {
674 		tocopy = sb->s_blocksize - offset < toread ?
675 				sb->s_blocksize - offset : toread;
676 
677 		tmp_bh.b_state = 0;
678 		tmp_bh.b_size = 1 << inode->i_blkbits;
679 		err = jfs_get_block(inode, blk, &tmp_bh, 0);
680 		if (err)
681 			return err;
682 		if (!buffer_mapped(&tmp_bh))	/* A hole? */
683 			memset(data, 0, tocopy);
684 		else {
685 			bh = sb_bread(sb, tmp_bh.b_blocknr);
686 			if (!bh)
687 				return -EIO;
688 			memcpy(data, bh->b_data+offset, tocopy);
689 			brelse(bh);
690 		}
691 		offset = 0;
692 		toread -= tocopy;
693 		data += tocopy;
694 		blk++;
695 	}
696 	return len;
697 }
698 
699 /* Write to quotafile */
700 static ssize_t jfs_quota_write(struct super_block *sb, int type,
701 			       const char *data, size_t len, loff_t off)
702 {
703 	struct inode *inode = sb_dqopt(sb)->files[type];
704 	sector_t blk = off >> sb->s_blocksize_bits;
705 	int err = 0;
706 	int offset = off & (sb->s_blocksize - 1);
707 	int tocopy;
708 	size_t towrite = len;
709 	struct buffer_head tmp_bh;
710 	struct buffer_head *bh;
711 
712 	mutex_lock(&inode->i_mutex);
713 	while (towrite > 0) {
714 		tocopy = sb->s_blocksize - offset < towrite ?
715 				sb->s_blocksize - offset : towrite;
716 
717 		tmp_bh.b_state = 0;
718 		tmp_bh.b_size = 1 << inode->i_blkbits;
719 		err = jfs_get_block(inode, blk, &tmp_bh, 1);
720 		if (err)
721 			goto out;
722 		if (offset || tocopy != sb->s_blocksize)
723 			bh = sb_bread(sb, tmp_bh.b_blocknr);
724 		else
725 			bh = sb_getblk(sb, tmp_bh.b_blocknr);
726 		if (!bh) {
727 			err = -EIO;
728 			goto out;
729 		}
730 		lock_buffer(bh);
731 		memcpy(bh->b_data+offset, data, tocopy);
732 		flush_dcache_page(bh->b_page);
733 		set_buffer_uptodate(bh);
734 		mark_buffer_dirty(bh);
735 		unlock_buffer(bh);
736 		brelse(bh);
737 		offset = 0;
738 		towrite -= tocopy;
739 		data += tocopy;
740 		blk++;
741 	}
742 out:
743 	if (len == towrite) {
744 		mutex_unlock(&inode->i_mutex);
745 		return err;
746 	}
747 	if (inode->i_size < off+len-towrite)
748 		i_size_write(inode, off+len-towrite);
749 	inode->i_version++;
750 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
751 	mark_inode_dirty(inode);
752 	mutex_unlock(&inode->i_mutex);
753 	return len - towrite;
754 }
755 
756 #endif
757 
758 static const struct super_operations jfs_super_operations = {
759 	.alloc_inode	= jfs_alloc_inode,
760 	.destroy_inode	= jfs_destroy_inode,
761 	.dirty_inode	= jfs_dirty_inode,
762 	.write_inode	= jfs_write_inode,
763 	.evict_inode	= jfs_evict_inode,
764 	.put_super	= jfs_put_super,
765 	.sync_fs	= jfs_sync_fs,
766 	.freeze_fs	= jfs_freeze,
767 	.unfreeze_fs	= jfs_unfreeze,
768 	.statfs		= jfs_statfs,
769 	.remount_fs	= jfs_remount,
770 	.show_options	= jfs_show_options,
771 #ifdef CONFIG_QUOTA
772 	.quota_read	= jfs_quota_read,
773 	.quota_write	= jfs_quota_write,
774 #endif
775 };
776 
777 static const struct export_operations jfs_export_operations = {
778 	.fh_to_dentry	= jfs_fh_to_dentry,
779 	.fh_to_parent	= jfs_fh_to_parent,
780 	.get_parent	= jfs_get_parent,
781 };
782 
783 static struct file_system_type jfs_fs_type = {
784 	.owner		= THIS_MODULE,
785 	.name		= "jfs",
786 	.get_sb		= jfs_get_sb,
787 	.kill_sb	= kill_block_super,
788 	.fs_flags	= FS_REQUIRES_DEV,
789 };
790 
791 static void init_once(void *foo)
792 {
793 	struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
794 
795 	memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
796 	INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
797 	init_rwsem(&jfs_ip->rdwrlock);
798 	mutex_init(&jfs_ip->commit_mutex);
799 	init_rwsem(&jfs_ip->xattr_sem);
800 	spin_lock_init(&jfs_ip->ag_lock);
801 	jfs_ip->active_ag = -1;
802 	inode_init_once(&jfs_ip->vfs_inode);
803 }
804 
805 static int __init init_jfs_fs(void)
806 {
807 	int i;
808 	int rc;
809 
810 	jfs_inode_cachep =
811 	    kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
812 			    SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
813 			    init_once);
814 	if (jfs_inode_cachep == NULL)
815 		return -ENOMEM;
816 
817 	/*
818 	 * Metapage initialization
819 	 */
820 	rc = metapage_init();
821 	if (rc) {
822 		jfs_err("metapage_init failed w/rc = %d", rc);
823 		goto free_slab;
824 	}
825 
826 	/*
827 	 * Transaction Manager initialization
828 	 */
829 	rc = txInit();
830 	if (rc) {
831 		jfs_err("txInit failed w/rc = %d", rc);
832 		goto free_metapage;
833 	}
834 
835 	/*
836 	 * I/O completion thread (endio)
837 	 */
838 	jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
839 	if (IS_ERR(jfsIOthread)) {
840 		rc = PTR_ERR(jfsIOthread);
841 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
842 		goto end_txmngr;
843 	}
844 
845 	if (commit_threads < 1)
846 		commit_threads = num_online_cpus();
847 	if (commit_threads > MAX_COMMIT_THREADS)
848 		commit_threads = MAX_COMMIT_THREADS;
849 
850 	for (i = 0; i < commit_threads; i++) {
851 		jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
852 		if (IS_ERR(jfsCommitThread[i])) {
853 			rc = PTR_ERR(jfsCommitThread[i]);
854 			jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
855 			commit_threads = i;
856 			goto kill_committask;
857 		}
858 	}
859 
860 	jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
861 	if (IS_ERR(jfsSyncThread)) {
862 		rc = PTR_ERR(jfsSyncThread);
863 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
864 		goto kill_committask;
865 	}
866 
867 #ifdef PROC_FS_JFS
868 	jfs_proc_init();
869 #endif
870 
871 	return register_filesystem(&jfs_fs_type);
872 
873 kill_committask:
874 	for (i = 0; i < commit_threads; i++)
875 		kthread_stop(jfsCommitThread[i]);
876 	kthread_stop(jfsIOthread);
877 end_txmngr:
878 	txExit();
879 free_metapage:
880 	metapage_exit();
881 free_slab:
882 	kmem_cache_destroy(jfs_inode_cachep);
883 	return rc;
884 }
885 
886 static void __exit exit_jfs_fs(void)
887 {
888 	int i;
889 
890 	jfs_info("exit_jfs_fs called");
891 
892 	txExit();
893 	metapage_exit();
894 
895 	kthread_stop(jfsIOthread);
896 	for (i = 0; i < commit_threads; i++)
897 		kthread_stop(jfsCommitThread[i]);
898 	kthread_stop(jfsSyncThread);
899 #ifdef PROC_FS_JFS
900 	jfs_proc_clean();
901 #endif
902 	unregister_filesystem(&jfs_fs_type);
903 	kmem_cache_destroy(jfs_inode_cachep);
904 }
905 
906 module_init(init_jfs_fs)
907 module_exit(exit_jfs_fs)
908