xref: /openbmc/linux/fs/jfs/jfs_mount.c (revision b593bce5) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) International Business Machines Corp., 2000-2004
4  */
5 
6 /*
7  * Module: jfs_mount.c
8  *
9  * note: file system in transition to aggregate/fileset:
10  *
11  * file system mount is interpreted as the mount of aggregate,
12  * if not already mounted, and mount of the single/only fileset in
13  * the aggregate;
14  *
15  * a file system/aggregate is represented by an internal inode
16  * (aka mount inode) initialized with aggregate superblock;
17  * each vfs represents a fileset, and points to its "fileset inode
18  * allocation map inode" (aka fileset inode):
19  * (an aggregate itself is structured recursively as a filset:
20  * an internal vfs is constructed and points to its "fileset inode
21  * allocation map inode" (aka aggregate inode) where each inode
22  * represents a fileset inode) so that inode number is mapped to
23  * on-disk inode in uniform way at both aggregate and fileset level;
24  *
25  * each vnode/inode of a fileset is linked to its vfs (to facilitate
26  * per fileset inode operations, e.g., unmount of a fileset, etc.);
27  * each inode points to the mount inode (to facilitate access to
28  * per aggregate information, e.g., block size, etc.) as well as
29  * its file set inode.
30  *
31  *   aggregate
32  *   ipmnt
33  *   mntvfs -> fileset ipimap+ -> aggregate ipbmap -> aggregate ipaimap;
34  *             fileset vfs     -> vp(1) <-> ... <-> vp(n) <->vproot;
35  */
36 
37 #include <linux/fs.h>
38 #include <linux/buffer_head.h>
39 
40 #include "jfs_incore.h"
41 #include "jfs_filsys.h"
42 #include "jfs_superblock.h"
43 #include "jfs_dmap.h"
44 #include "jfs_imap.h"
45 #include "jfs_metapage.h"
46 #include "jfs_debug.h"
47 
48 
49 /*
50  * forward references
51  */
52 static int chkSuper(struct super_block *);
53 static int logMOUNT(struct super_block *sb);
54 
55 /*
56  * NAME:	jfs_mount(sb)
57  *
58  * FUNCTION:	vfs_mount()
59  *
60  * PARAMETER:	sb	- super block
61  *
62  * RETURN:	-EBUSY	- device already mounted or open for write
63  *		-EBUSY	- cvrdvp already mounted;
64  *		-EBUSY	- mount table full
65  *		-ENOTDIR- cvrdvp not directory on a device mount
66  *		-ENXIO	- device open failure
67  */
68 int jfs_mount(struct super_block *sb)
69 {
70 	int rc = 0;		/* Return code */
71 	struct jfs_sb_info *sbi = JFS_SBI(sb);
72 	struct inode *ipaimap = NULL;
73 	struct inode *ipaimap2 = NULL;
74 	struct inode *ipimap = NULL;
75 	struct inode *ipbmap = NULL;
76 
77 	/*
78 	 * read/validate superblock
79 	 * (initialize mount inode from the superblock)
80 	 */
81 	if ((rc = chkSuper(sb))) {
82 		goto errout20;
83 	}
84 
85 	ipaimap = diReadSpecial(sb, AGGREGATE_I, 0);
86 	if (ipaimap == NULL) {
87 		jfs_err("jfs_mount: Failed to read AGGREGATE_I");
88 		rc = -EIO;
89 		goto errout20;
90 	}
91 	sbi->ipaimap = ipaimap;
92 
93 	jfs_info("jfs_mount: ipaimap:0x%p", ipaimap);
94 
95 	/*
96 	 * initialize aggregate inode allocation map
97 	 */
98 	if ((rc = diMount(ipaimap))) {
99 		jfs_err("jfs_mount: diMount(ipaimap) failed w/rc = %d", rc);
100 		goto errout21;
101 	}
102 
103 	/*
104 	 * open aggregate block allocation map
105 	 */
106 	ipbmap = diReadSpecial(sb, BMAP_I, 0);
107 	if (ipbmap == NULL) {
108 		rc = -EIO;
109 		goto errout22;
110 	}
111 
112 	jfs_info("jfs_mount: ipbmap:0x%p", ipbmap);
113 
114 	sbi->ipbmap = ipbmap;
115 
116 	/*
117 	 * initialize aggregate block allocation map
118 	 */
119 	if ((rc = dbMount(ipbmap))) {
120 		jfs_err("jfs_mount: dbMount failed w/rc = %d", rc);
121 		goto errout22;
122 	}
123 
124 	/*
125 	 * open the secondary aggregate inode allocation map
126 	 *
127 	 * This is a duplicate of the aggregate inode allocation map.
128 	 *
129 	 * hand craft a vfs in the same fashion as we did to read ipaimap.
130 	 * By adding INOSPEREXT (32) to the inode number, we are telling
131 	 * diReadSpecial that we are reading from the secondary aggregate
132 	 * inode table.  This also creates a unique entry in the inode hash
133 	 * table.
134 	 */
135 	if ((sbi->mntflag & JFS_BAD_SAIT) == 0) {
136 		ipaimap2 = diReadSpecial(sb, AGGREGATE_I, 1);
137 		if (!ipaimap2) {
138 			jfs_err("jfs_mount: Failed to read AGGREGATE_I");
139 			rc = -EIO;
140 			goto errout35;
141 		}
142 		sbi->ipaimap2 = ipaimap2;
143 
144 		jfs_info("jfs_mount: ipaimap2:0x%p", ipaimap2);
145 
146 		/*
147 		 * initialize secondary aggregate inode allocation map
148 		 */
149 		if ((rc = diMount(ipaimap2))) {
150 			jfs_err("jfs_mount: diMount(ipaimap2) failed, rc = %d",
151 				rc);
152 			goto errout35;
153 		}
154 	} else
155 		/* Secondary aggregate inode table is not valid */
156 		sbi->ipaimap2 = NULL;
157 
158 	/*
159 	 *	mount (the only/single) fileset
160 	 */
161 	/*
162 	 * open fileset inode allocation map (aka fileset inode)
163 	 */
164 	ipimap = diReadSpecial(sb, FILESYSTEM_I, 0);
165 	if (ipimap == NULL) {
166 		jfs_err("jfs_mount: Failed to read FILESYSTEM_I");
167 		/* open fileset secondary inode allocation map */
168 		rc = -EIO;
169 		goto errout40;
170 	}
171 	jfs_info("jfs_mount: ipimap:0x%p", ipimap);
172 
173 	/* map further access of per fileset inodes by the fileset inode */
174 	sbi->ipimap = ipimap;
175 
176 	/* initialize fileset inode allocation map */
177 	if ((rc = diMount(ipimap))) {
178 		jfs_err("jfs_mount: diMount failed w/rc = %d", rc);
179 		goto errout41;
180 	}
181 
182 	goto out;
183 
184 	/*
185 	 *	unwind on error
186 	 */
187       errout41:		/* close fileset inode allocation map inode */
188 	diFreeSpecial(ipimap);
189 
190       errout40:		/* fileset closed */
191 
192 	/* close secondary aggregate inode allocation map */
193 	if (ipaimap2) {
194 		diUnmount(ipaimap2, 1);
195 		diFreeSpecial(ipaimap2);
196 	}
197 
198       errout35:
199 
200 	/* close aggregate block allocation map */
201 	dbUnmount(ipbmap, 1);
202 	diFreeSpecial(ipbmap);
203 
204       errout22:		/* close aggregate inode allocation map */
205 
206 	diUnmount(ipaimap, 1);
207 
208       errout21:		/* close aggregate inodes */
209 	diFreeSpecial(ipaimap);
210       errout20:		/* aggregate closed */
211 
212       out:
213 
214 	if (rc)
215 		jfs_err("Mount JFS Failure: %d", rc);
216 
217 	return rc;
218 }
219 
220 /*
221  * NAME:	jfs_mount_rw(sb, remount)
222  *
223  * FUNCTION:	Completes read-write mount, or remounts read-only volume
224  *		as read-write
225  */
226 int jfs_mount_rw(struct super_block *sb, int remount)
227 {
228 	struct jfs_sb_info *sbi = JFS_SBI(sb);
229 	int rc;
230 
231 	/*
232 	 * If we are re-mounting a previously read-only volume, we want to
233 	 * re-read the inode and block maps, since fsck.jfs may have updated
234 	 * them.
235 	 */
236 	if (remount) {
237 		if (chkSuper(sb) || (sbi->state != FM_CLEAN))
238 			return -EINVAL;
239 
240 		truncate_inode_pages(sbi->ipimap->i_mapping, 0);
241 		truncate_inode_pages(sbi->ipbmap->i_mapping, 0);
242 		diUnmount(sbi->ipimap, 1);
243 		if ((rc = diMount(sbi->ipimap))) {
244 			jfs_err("jfs_mount_rw: diMount failed!");
245 			return rc;
246 		}
247 
248 		dbUnmount(sbi->ipbmap, 1);
249 		if ((rc = dbMount(sbi->ipbmap))) {
250 			jfs_err("jfs_mount_rw: dbMount failed!");
251 			return rc;
252 		}
253 	}
254 
255 	/*
256 	 * open/initialize log
257 	 */
258 	if ((rc = lmLogOpen(sb)))
259 		return rc;
260 
261 	/*
262 	 * update file system superblock;
263 	 */
264 	if ((rc = updateSuper(sb, FM_MOUNT))) {
265 		jfs_err("jfs_mount: updateSuper failed w/rc = %d", rc);
266 		lmLogClose(sb);
267 		return rc;
268 	}
269 
270 	/*
271 	 * write MOUNT log record of the file system
272 	 */
273 	logMOUNT(sb);
274 
275 	return rc;
276 }
277 
278 /*
279  *	chkSuper()
280  *
281  * validate the superblock of the file system to be mounted and
282  * get the file system parameters.
283  *
284  * returns
285  *	0 with fragsize set if check successful
286  *	error code if not successful
287  */
288 static int chkSuper(struct super_block *sb)
289 {
290 	int rc = 0;
291 	struct jfs_sb_info *sbi = JFS_SBI(sb);
292 	struct jfs_superblock *j_sb;
293 	struct buffer_head *bh;
294 	int AIM_bytesize, AIT_bytesize;
295 	int expected_AIM_bytesize, expected_AIT_bytesize;
296 	s64 AIM_byte_addr, AIT_byte_addr, fsckwsp_addr;
297 	s64 byte_addr_diff0, byte_addr_diff1;
298 	s32 bsize;
299 
300 	if ((rc = readSuper(sb, &bh)))
301 		return rc;
302 	j_sb = (struct jfs_superblock *)bh->b_data;
303 
304 	/*
305 	 * validate superblock
306 	 */
307 	/* validate fs signature */
308 	if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||
309 	    le32_to_cpu(j_sb->s_version) > JFS_VERSION) {
310 		rc = -EINVAL;
311 		goto out;
312 	}
313 
314 	bsize = le32_to_cpu(j_sb->s_bsize);
315 #ifdef _JFS_4K
316 	if (bsize != PSIZE) {
317 		jfs_err("Currently only 4K block size supported!");
318 		rc = -EINVAL;
319 		goto out;
320 	}
321 #endif				/* _JFS_4K */
322 
323 	jfs_info("superblock: flag:0x%08x state:0x%08x size:0x%Lx",
324 		 le32_to_cpu(j_sb->s_flag), le32_to_cpu(j_sb->s_state),
325 		 (unsigned long long) le64_to_cpu(j_sb->s_size));
326 
327 	/* validate the descriptors for Secondary AIM and AIT */
328 	if ((j_sb->s_flag & cpu_to_le32(JFS_BAD_SAIT)) !=
329 	    cpu_to_le32(JFS_BAD_SAIT)) {
330 		expected_AIM_bytesize = 2 * PSIZE;
331 		AIM_bytesize = lengthPXD(&(j_sb->s_aim2)) * bsize;
332 		expected_AIT_bytesize = 4 * PSIZE;
333 		AIT_bytesize = lengthPXD(&(j_sb->s_ait2)) * bsize;
334 		AIM_byte_addr = addressPXD(&(j_sb->s_aim2)) * bsize;
335 		AIT_byte_addr = addressPXD(&(j_sb->s_ait2)) * bsize;
336 		byte_addr_diff0 = AIT_byte_addr - AIM_byte_addr;
337 		fsckwsp_addr = addressPXD(&(j_sb->s_fsckpxd)) * bsize;
338 		byte_addr_diff1 = fsckwsp_addr - AIT_byte_addr;
339 		if ((AIM_bytesize != expected_AIM_bytesize) ||
340 		    (AIT_bytesize != expected_AIT_bytesize) ||
341 		    (byte_addr_diff0 != AIM_bytesize) ||
342 		    (byte_addr_diff1 <= AIT_bytesize))
343 			j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);
344 	}
345 
346 	if ((j_sb->s_flag & cpu_to_le32(JFS_GROUPCOMMIT)) !=
347 	    cpu_to_le32(JFS_GROUPCOMMIT))
348 		j_sb->s_flag |= cpu_to_le32(JFS_GROUPCOMMIT);
349 
350 	/* validate fs state */
351 	if (j_sb->s_state != cpu_to_le32(FM_CLEAN) &&
352 	    !sb_rdonly(sb)) {
353 		jfs_err("jfs_mount: Mount Failure: File System Dirty.");
354 		rc = -EINVAL;
355 		goto out;
356 	}
357 
358 	sbi->state = le32_to_cpu(j_sb->s_state);
359 	sbi->mntflag = le32_to_cpu(j_sb->s_flag);
360 
361 	/*
362 	 * JFS always does I/O by 4K pages.  Don't tell the buffer cache
363 	 * that we use anything else (leave s_blocksize alone).
364 	 */
365 	sbi->bsize = bsize;
366 	sbi->l2bsize = le16_to_cpu(j_sb->s_l2bsize);
367 
368 	/*
369 	 * For now, ignore s_pbsize, l2bfactor.  All I/O going through buffer
370 	 * cache.
371 	 */
372 	sbi->nbperpage = PSIZE >> sbi->l2bsize;
373 	sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;
374 	sbi->l2niperblk = sbi->l2bsize - L2DISIZE;
375 	if (sbi->mntflag & JFS_INLINELOG)
376 		sbi->logpxd = j_sb->s_logpxd;
377 	else {
378 		sbi->logdev = new_decode_dev(le32_to_cpu(j_sb->s_logdev));
379 		uuid_copy(&sbi->uuid, &j_sb->s_uuid);
380 		uuid_copy(&sbi->loguuid, &j_sb->s_loguuid);
381 	}
382 	sbi->fsckpxd = j_sb->s_fsckpxd;
383 	sbi->ait2 = j_sb->s_ait2;
384 
385       out:
386 	brelse(bh);
387 	return rc;
388 }
389 
390 
391 /*
392  *	updateSuper()
393  *
394  * update synchronously superblock if it is mounted read-write.
395  */
396 int updateSuper(struct super_block *sb, uint state)
397 {
398 	struct jfs_superblock *j_sb;
399 	struct jfs_sb_info *sbi = JFS_SBI(sb);
400 	struct buffer_head *bh;
401 	int rc;
402 
403 	if (sbi->flag & JFS_NOINTEGRITY) {
404 		if (state == FM_DIRTY) {
405 			sbi->p_state = state;
406 			return 0;
407 		} else if (state == FM_MOUNT) {
408 			sbi->p_state = sbi->state;
409 			state = FM_DIRTY;
410 		} else if (state == FM_CLEAN) {
411 			state = sbi->p_state;
412 		} else
413 			jfs_err("updateSuper: bad state");
414 	} else if (sbi->state == FM_DIRTY)
415 		return 0;
416 
417 	if ((rc = readSuper(sb, &bh)))
418 		return rc;
419 
420 	j_sb = (struct jfs_superblock *)bh->b_data;
421 
422 	j_sb->s_state = cpu_to_le32(state);
423 	sbi->state = state;
424 
425 	if (state == FM_MOUNT) {
426 		/* record log's dev_t and mount serial number */
427 		j_sb->s_logdev = cpu_to_le32(new_encode_dev(sbi->log->bdev->bd_dev));
428 		j_sb->s_logserial = cpu_to_le32(sbi->log->serial);
429 	} else if (state == FM_CLEAN) {
430 		/*
431 		 * If this volume is shared with OS/2, OS/2 will need to
432 		 * recalculate DASD usage, since we don't deal with it.
433 		 */
434 		if (j_sb->s_flag & cpu_to_le32(JFS_DASD_ENABLED))
435 			j_sb->s_flag |= cpu_to_le32(JFS_DASD_PRIME);
436 	}
437 
438 	mark_buffer_dirty(bh);
439 	sync_dirty_buffer(bh);
440 	brelse(bh);
441 
442 	return 0;
443 }
444 
445 
446 /*
447  *	readSuper()
448  *
449  * read superblock by raw sector address
450  */
451 int readSuper(struct super_block *sb, struct buffer_head **bpp)
452 {
453 	/* read in primary superblock */
454 	*bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);
455 	if (*bpp)
456 		return 0;
457 
458 	/* read in secondary/replicated superblock */
459 	*bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
460 	if (*bpp)
461 		return 0;
462 
463 	return -EIO;
464 }
465 
466 
467 /*
468  *	logMOUNT()
469  *
470  * function: write a MOUNT log record for file system.
471  *
472  * MOUNT record keeps logredo() from processing log records
473  * for this file system past this point in log.
474  * it is harmless if mount fails.
475  *
476  * note: MOUNT record is at aggregate level, not at fileset level,
477  * since log records of previous mounts of a fileset
478  * (e.g., AFTER record of extent allocation) have to be processed
479  * to update block allocation map at aggregate level.
480  */
481 static int logMOUNT(struct super_block *sb)
482 {
483 	struct jfs_log *log = JFS_SBI(sb)->log;
484 	struct lrd lrd;
485 
486 	lrd.logtid = 0;
487 	lrd.backchain = 0;
488 	lrd.type = cpu_to_le16(LOG_MOUNT);
489 	lrd.length = 0;
490 	lrd.aggregate = cpu_to_le32(new_encode_dev(sb->s_bdev->bd_dev));
491 	lmLog(log, NULL, &lrd, NULL);
492 
493 	return 0;
494 }
495