xref: /openbmc/linux/fs/jfs/jfs_mount.c (revision 752beb5e)
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  */
65 static int chkSuper(struct super_block *);
66 static 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  */
81 int 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  */
239 int 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  */
301 static 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_rdonly(sb)) {
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 		uuid_copy(&sbi->uuid, &j_sb->s_uuid);
393 		uuid_copy(&sbi->loguuid, &j_sb->s_loguuid);
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  */
409 int 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  */
464 int 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  */
494 static 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