1/*
2 *   Copyright (C) International Business Machines Corp., 2000-2004
3 *
4 *   This program is free software;  you can redistribute it and/or modify
5 *   it under the terms of the GNU General Public License as published by
6 *   the Free Software Foundation; either version 2 of the License, or
7 *   (at your option) any later version.
8 *
9 *   This program is distributed in the hope that it will be useful,
10 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
11 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
12 *   the GNU General Public License for more details.
13 *
14 *   You should have received a copy of the GNU General Public License
15 *   along with this program;  if not, write to the Free Software
16 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19/*
20 * Module: jfs_mount.c
21 *
22 * note: file system in transition to aggregate/fileset:
23 *
24 * file system mount is interpreted as the mount of aggregate,
25 * if not already mounted, and mount of the single/only fileset in
26 * the aggregate;
27 *
28 * a file system/aggregate is represented by an internal inode
29 * (aka mount inode) initialized with aggregate superblock;
30 * each vfs represents a fileset, and points to its "fileset inode
31 * allocation map inode" (aka fileset inode):
32 * (an aggregate itself is structured recursively as a filset:
33 * an internal vfs is constructed and points to its "fileset inode
34 * allocation map inode" (aka aggregate inode) where each inode
35 * represents a fileset inode) so that inode number is mapped to
36 * on-disk inode in uniform way at both aggregate and fileset level;
37 *
38 * each vnode/inode of a fileset is linked to its vfs (to facilitate
39 * per fileset inode operations, e.g., unmount of a fileset, etc.);
40 * each inode points to the mount inode (to facilitate access to
41 * per aggregate information, e.g., block size, etc.) as well as
42 * its file set inode.
43 *
44 *   aggregate
45 *   ipmnt
46 *   mntvfs -> fileset ipimap+ -> aggregate ipbmap -> aggregate ipaimap;
47 *             fileset vfs     -> vp(1) <-> ... <-> vp(n) <->vproot;
48 */
49
50#include <linux/fs.h>
51#include <linux/buffer_head.h>
52
53#include "jfs_incore.h"
54#include "jfs_filsys.h"
55#include "jfs_superblock.h"
56#include "jfs_dmap.h"
57#include "jfs_imap.h"
58#include "jfs_metapage.h"
59#include "jfs_debug.h"
60
61
62/*
63 * forward references
64 */
65static int chkSuper(struct super_block *);
66static int logMOUNT(struct super_block *sb);
67
68/*
69 * NAME:	jfs_mount(sb)
70 *
71 * FUNCTION:	vfs_mount()
72 *
73 * PARAMETER:	sb	- super block
74 *
75 * RETURN:	-EBUSY	- device already mounted or open for write
76 *		-EBUSY	- cvrdvp already mounted;
77 *		-EBUSY	- mount table full
78 *		-ENOTDIR- cvrdvp not directory on a device mount
79 *		-ENXIO	- device open failure
80 */
81int jfs_mount(struct super_block *sb)
82{
83	int rc = 0;		/* Return code */
84	struct jfs_sb_info *sbi = JFS_SBI(sb);
85	struct inode *ipaimap = NULL;
86	struct inode *ipaimap2 = NULL;
87	struct inode *ipimap = NULL;
88	struct inode *ipbmap = NULL;
89
90	/*
91	 * read/validate superblock
92	 * (initialize mount inode from the superblock)
93	 */
94	if ((rc = chkSuper(sb))) {
95		goto errout20;
96	}
97
98	ipaimap = diReadSpecial(sb, AGGREGATE_I, 0);
99	if (ipaimap == NULL) {
100		jfs_err("jfs_mount: Failed to read AGGREGATE_I");
101		rc = -EIO;
102		goto errout20;
103	}
104	sbi->ipaimap = ipaimap;
105
106	jfs_info("jfs_mount: ipaimap:0x%p", ipaimap);
107
108	/*
109	 * initialize aggregate inode allocation map
110	 */
111	if ((rc = diMount(ipaimap))) {
112		jfs_err("jfs_mount: diMount(ipaimap) failed w/rc = %d", rc);
113		goto errout21;
114	}
115
116	/*
117	 * open aggregate block allocation map
118	 */
119	ipbmap = diReadSpecial(sb, BMAP_I, 0);
120	if (ipbmap == NULL) {
121		rc = -EIO;
122		goto errout22;
123	}
124
125	jfs_info("jfs_mount: ipbmap:0x%p", ipbmap);
126
127	sbi->ipbmap = ipbmap;
128
129	/*
130	 * initialize aggregate block allocation map
131	 */
132	if ((rc = dbMount(ipbmap))) {
133		jfs_err("jfs_mount: dbMount failed w/rc = %d", rc);
134		goto errout22;
135	}
136
137	/*
138	 * open the secondary aggregate inode allocation map
139	 *
140	 * This is a duplicate of the aggregate inode allocation map.
141	 *
142	 * hand craft a vfs in the same fashion as we did to read ipaimap.
143	 * By adding INOSPEREXT (32) to the inode number, we are telling
144	 * diReadSpecial that we are reading from the secondary aggregate
145	 * inode table.  This also creates a unique entry in the inode hash
146	 * table.
147	 */
148	if ((sbi->mntflag & JFS_BAD_SAIT) == 0) {
149		ipaimap2 = diReadSpecial(sb, AGGREGATE_I, 1);
150		if (!ipaimap2) {
151			jfs_err("jfs_mount: Failed to read AGGREGATE_I");
152			rc = -EIO;
153			goto errout35;
154		}
155		sbi->ipaimap2 = ipaimap2;
156
157		jfs_info("jfs_mount: ipaimap2:0x%p", ipaimap2);
158
159		/*
160		 * initialize secondary aggregate inode allocation map
161		 */
162		if ((rc = diMount(ipaimap2))) {
163			jfs_err("jfs_mount: diMount(ipaimap2) failed, rc = %d",
164				rc);
165			goto errout35;
166		}
167	} else
168		/* Secondary aggregate inode table is not valid */
169		sbi->ipaimap2 = NULL;
170
171	/*
172	 *	mount (the only/single) fileset
173	 */
174	/*
175	 * open fileset inode allocation map (aka fileset inode)
176	 */
177	ipimap = diReadSpecial(sb, FILESYSTEM_I, 0);
178	if (ipimap == NULL) {
179		jfs_err("jfs_mount: Failed to read FILESYSTEM_I");
180		/* open fileset secondary inode allocation map */
181		rc = -EIO;
182		goto errout40;
183	}
184	jfs_info("jfs_mount: ipimap:0x%p", ipimap);
185
186	/* map further access of per fileset inodes by the fileset inode */
187	sbi->ipimap = ipimap;
188
189	/* initialize fileset inode allocation map */
190	if ((rc = diMount(ipimap))) {
191		jfs_err("jfs_mount: diMount failed w/rc = %d", rc);
192		goto errout41;
193	}
194
195	goto out;
196
197	/*
198	 *	unwind on error
199	 */
200      errout41:		/* close fileset inode allocation map inode */
201	diFreeSpecial(ipimap);
202
203      errout40:		/* fileset closed */
204
205	/* close secondary aggregate inode allocation map */
206	if (ipaimap2) {
207		diUnmount(ipaimap2, 1);
208		diFreeSpecial(ipaimap2);
209	}
210
211      errout35:
212
213	/* close aggregate block allocation map */
214	dbUnmount(ipbmap, 1);
215	diFreeSpecial(ipbmap);
216
217      errout22:		/* close aggregate inode allocation map */
218
219	diUnmount(ipaimap, 1);
220
221      errout21:		/* close aggregate inodes */
222	diFreeSpecial(ipaimap);
223      errout20:		/* aggregate closed */
224
225      out:
226
227	if (rc)
228		jfs_err("Mount JFS Failure: %d", rc);
229
230	return rc;
231}
232
233/*
234 * NAME:	jfs_mount_rw(sb, remount)
235 *
236 * FUNCTION:	Completes read-write mount, or remounts read-only volume
237 *		as read-write
238 */
239int jfs_mount_rw(struct super_block *sb, int remount)
240{
241	struct jfs_sb_info *sbi = JFS_SBI(sb);
242	int rc;
243
244	/*
245	 * If we are re-mounting a previously read-only volume, we want to
246	 * re-read the inode and block maps, since fsck.jfs may have updated
247	 * them.
248	 */
249	if (remount) {
250		if (chkSuper(sb) || (sbi->state != FM_CLEAN))
251			return -EINVAL;
252
253		truncate_inode_pages(sbi->ipimap->i_mapping, 0);
254		truncate_inode_pages(sbi->ipbmap->i_mapping, 0);
255		diUnmount(sbi->ipimap, 1);
256		if ((rc = diMount(sbi->ipimap))) {
257			jfs_err("jfs_mount_rw: diMount failed!");
258			return rc;
259		}
260
261		dbUnmount(sbi->ipbmap, 1);
262		if ((rc = dbMount(sbi->ipbmap))) {
263			jfs_err("jfs_mount_rw: dbMount failed!");
264			return rc;
265		}
266	}
267
268	/*
269	 * open/initialize log
270	 */
271	if ((rc = lmLogOpen(sb)))
272		return rc;
273
274	/*
275	 * update file system superblock;
276	 */
277	if ((rc = updateSuper(sb, FM_MOUNT))) {
278		jfs_err("jfs_mount: updateSuper failed w/rc = %d", rc);
279		lmLogClose(sb);
280		return rc;
281	}
282
283	/*
284	 * write MOUNT log record of the file system
285	 */
286	logMOUNT(sb);
287
288	return rc;
289}
290
291/*
292 *	chkSuper()
293 *
294 * validate the superblock of the file system to be mounted and
295 * get the file system parameters.
296 *
297 * returns
298 *	0 with fragsize set if check successful
299 *	error code if not successful
300 */
301static int chkSuper(struct super_block *sb)
302{
303	int rc = 0;
304	struct jfs_sb_info *sbi = JFS_SBI(sb);
305	struct jfs_superblock *j_sb;
306	struct buffer_head *bh;
307	int AIM_bytesize, AIT_bytesize;
308	int expected_AIM_bytesize, expected_AIT_bytesize;
309	s64 AIM_byte_addr, AIT_byte_addr, fsckwsp_addr;
310	s64 byte_addr_diff0, byte_addr_diff1;
311	s32 bsize;
312
313	if ((rc = readSuper(sb, &bh)))
314		return rc;
315	j_sb = (struct jfs_superblock *)bh->b_data;
316
317	/*
318	 * validate superblock
319	 */
320	/* validate fs signature */
321	if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||
322	    le32_to_cpu(j_sb->s_version) > JFS_VERSION) {
323		rc = -EINVAL;
324		goto out;
325	}
326
327	bsize = le32_to_cpu(j_sb->s_bsize);
328#ifdef _JFS_4K
329	if (bsize != PSIZE) {
330		jfs_err("Currently only 4K block size supported!");
331		rc = -EINVAL;
332		goto out;
333	}
334#endif				/* _JFS_4K */
335
336	jfs_info("superblock: flag:0x%08x state:0x%08x size:0x%Lx",
337		 le32_to_cpu(j_sb->s_flag), le32_to_cpu(j_sb->s_state),
338		 (unsigned long long) le64_to_cpu(j_sb->s_size));
339
340	/* validate the descriptors for Secondary AIM and AIT */
341	if ((j_sb->s_flag & cpu_to_le32(JFS_BAD_SAIT)) !=
342	    cpu_to_le32(JFS_BAD_SAIT)) {
343		expected_AIM_bytesize = 2 * PSIZE;
344		AIM_bytesize = lengthPXD(&(j_sb->s_aim2)) * bsize;
345		expected_AIT_bytesize = 4 * PSIZE;
346		AIT_bytesize = lengthPXD(&(j_sb->s_ait2)) * bsize;
347		AIM_byte_addr = addressPXD(&(j_sb->s_aim2)) * bsize;
348		AIT_byte_addr = addressPXD(&(j_sb->s_ait2)) * bsize;
349		byte_addr_diff0 = AIT_byte_addr - AIM_byte_addr;
350		fsckwsp_addr = addressPXD(&(j_sb->s_fsckpxd)) * bsize;
351		byte_addr_diff1 = fsckwsp_addr - AIT_byte_addr;
352		if ((AIM_bytesize != expected_AIM_bytesize) ||
353		    (AIT_bytesize != expected_AIT_bytesize) ||
354		    (byte_addr_diff0 != AIM_bytesize) ||
355		    (byte_addr_diff1 <= AIT_bytesize))
356			j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);
357	}
358
359	if ((j_sb->s_flag & cpu_to_le32(JFS_GROUPCOMMIT)) !=
360	    cpu_to_le32(JFS_GROUPCOMMIT))
361		j_sb->s_flag |= cpu_to_le32(JFS_GROUPCOMMIT);
362
363	/* validate fs state */
364	if (j_sb->s_state != cpu_to_le32(FM_CLEAN) &&
365	    !(sb->s_flags & MS_RDONLY)) {
366		jfs_err("jfs_mount: Mount Failure: File System Dirty.");
367		rc = -EINVAL;
368		goto out;
369	}
370
371	sbi->state = le32_to_cpu(j_sb->s_state);
372	sbi->mntflag = le32_to_cpu(j_sb->s_flag);
373
374	/*
375	 * JFS always does I/O by 4K pages.  Don't tell the buffer cache
376	 * that we use anything else (leave s_blocksize alone).
377	 */
378	sbi->bsize = bsize;
379	sbi->l2bsize = le16_to_cpu(j_sb->s_l2bsize);
380
381	/*
382	 * For now, ignore s_pbsize, l2bfactor.  All I/O going through buffer
383	 * cache.
384	 */
385	sbi->nbperpage = PSIZE >> sbi->l2bsize;
386	sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;
387	sbi->l2niperblk = sbi->l2bsize - L2DISIZE;
388	if (sbi->mntflag & JFS_INLINELOG)
389		sbi->logpxd = j_sb->s_logpxd;
390	else {
391		sbi->logdev = new_decode_dev(le32_to_cpu(j_sb->s_logdev));
392		memcpy(sbi->uuid, j_sb->s_uuid, sizeof(sbi->uuid));
393		memcpy(sbi->loguuid, j_sb->s_loguuid, sizeof(sbi->uuid));
394	}
395	sbi->fsckpxd = j_sb->s_fsckpxd;
396	sbi->ait2 = j_sb->s_ait2;
397
398      out:
399	brelse(bh);
400	return rc;
401}
402
403
404/*
405 *	updateSuper()
406 *
407 * update synchronously superblock if it is mounted read-write.
408 */
409int updateSuper(struct super_block *sb, uint state)
410{
411	struct jfs_superblock *j_sb;
412	struct jfs_sb_info *sbi = JFS_SBI(sb);
413	struct buffer_head *bh;
414	int rc;
415
416	if (sbi->flag & JFS_NOINTEGRITY) {
417		if (state == FM_DIRTY) {
418			sbi->p_state = state;
419			return 0;
420		} else if (state == FM_MOUNT) {
421			sbi->p_state = sbi->state;
422			state = FM_DIRTY;
423		} else if (state == FM_CLEAN) {
424			state = sbi->p_state;
425		} else
426			jfs_err("updateSuper: bad state");
427	} else if (sbi->state == FM_DIRTY)
428		return 0;
429
430	if ((rc = readSuper(sb, &bh)))
431		return rc;
432
433	j_sb = (struct jfs_superblock *)bh->b_data;
434
435	j_sb->s_state = cpu_to_le32(state);
436	sbi->state = state;
437
438	if (state == FM_MOUNT) {
439		/* record log's dev_t and mount serial number */
440		j_sb->s_logdev = cpu_to_le32(new_encode_dev(sbi->log->bdev->bd_dev));
441		j_sb->s_logserial = cpu_to_le32(sbi->log->serial);
442	} else if (state == FM_CLEAN) {
443		/*
444		 * If this volume is shared with OS/2, OS/2 will need to
445		 * recalculate DASD usage, since we don't deal with it.
446		 */
447		if (j_sb->s_flag & cpu_to_le32(JFS_DASD_ENABLED))
448			j_sb->s_flag |= cpu_to_le32(JFS_DASD_PRIME);
449	}
450
451	mark_buffer_dirty(bh);
452	sync_dirty_buffer(bh);
453	brelse(bh);
454
455	return 0;
456}
457
458
459/*
460 *	readSuper()
461 *
462 * read superblock by raw sector address
463 */
464int readSuper(struct super_block *sb, struct buffer_head **bpp)
465{
466	/* read in primary superblock */
467	*bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);
468	if (*bpp)
469		return 0;
470
471	/* read in secondary/replicated superblock */
472	*bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
473	if (*bpp)
474		return 0;
475
476	return -EIO;
477}
478
479
480/*
481 *	logMOUNT()
482 *
483 * function: write a MOUNT log record for file system.
484 *
485 * MOUNT record keeps logredo() from processing log records
486 * for this file system past this point in log.
487 * it is harmless if mount fails.
488 *
489 * note: MOUNT record is at aggregate level, not at fileset level,
490 * since log records of previous mounts of a fileset
491 * (e.g., AFTER record of extent allocation) have to be processed
492 * to update block allocation map at aggregate level.
493 */
494static int logMOUNT(struct super_block *sb)
495{
496	struct jfs_log *log = JFS_SBI(sb)->log;
497	struct lrd lrd;
498
499	lrd.logtid = 0;
500	lrd.backchain = 0;
501	lrd.type = cpu_to_le16(LOG_MOUNT);
502	lrd.length = 0;
503	lrd.aggregate = cpu_to_le32(new_encode_dev(sb->s_bdev->bd_dev));
504	lmLog(log, NULL, &lrd, NULL);
505
506	return 0;
507}
508