xref: /kernel/linux/linux-5.10/fs/jfs/jfs_mount.c (revision 8c2ecf20)
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#include <linux/blkdev.h>
40#include <linux/log2.h>
41
42#include "jfs_incore.h"
43#include "jfs_filsys.h"
44#include "jfs_superblock.h"
45#include "jfs_dmap.h"
46#include "jfs_imap.h"
47#include "jfs_metapage.h"
48#include "jfs_debug.h"
49
50
51/*
52 * forward references
53 */
54static int chkSuper(struct super_block *);
55static int logMOUNT(struct super_block *sb);
56
57/*
58 * NAME:	jfs_mount(sb)
59 *
60 * FUNCTION:	vfs_mount()
61 *
62 * PARAMETER:	sb	- super block
63 *
64 * RETURN:	-EBUSY	- device already mounted or open for write
65 *		-EBUSY	- cvrdvp already mounted;
66 *		-EBUSY	- mount table full
67 *		-ENOTDIR- cvrdvp not directory on a device mount
68 *		-ENXIO	- device open failure
69 */
70int jfs_mount(struct super_block *sb)
71{
72	int rc = 0;		/* Return code */
73	struct jfs_sb_info *sbi = JFS_SBI(sb);
74	struct inode *ipaimap = NULL;
75	struct inode *ipaimap2 = NULL;
76	struct inode *ipimap = NULL;
77	struct inode *ipbmap = NULL;
78
79	/*
80	 * read/validate superblock
81	 * (initialize mount inode from the superblock)
82	 */
83	if ((rc = chkSuper(sb))) {
84		goto out;
85	}
86
87	ipaimap = diReadSpecial(sb, AGGREGATE_I, 0);
88	if (ipaimap == NULL) {
89		jfs_err("jfs_mount: Failed to read AGGREGATE_I");
90		rc = -EIO;
91		goto out;
92	}
93	sbi->ipaimap = ipaimap;
94
95	jfs_info("jfs_mount: ipaimap:0x%p", ipaimap);
96
97	/*
98	 * initialize aggregate inode allocation map
99	 */
100	if ((rc = diMount(ipaimap))) {
101		jfs_err("jfs_mount: diMount(ipaimap) failed w/rc = %d", rc);
102		goto err_ipaimap;
103	}
104
105	/*
106	 * open aggregate block allocation map
107	 */
108	ipbmap = diReadSpecial(sb, BMAP_I, 0);
109	if (ipbmap == NULL) {
110		rc = -EIO;
111		goto err_umount_ipaimap;
112	}
113
114	jfs_info("jfs_mount: ipbmap:0x%p", ipbmap);
115
116	sbi->ipbmap = ipbmap;
117
118	/*
119	 * initialize aggregate block allocation map
120	 */
121	if ((rc = dbMount(ipbmap))) {
122		jfs_err("jfs_mount: dbMount failed w/rc = %d", rc);
123		goto err_ipbmap;
124	}
125
126	/*
127	 * open the secondary aggregate inode allocation map
128	 *
129	 * This is a duplicate of the aggregate inode allocation map.
130	 *
131	 * hand craft a vfs in the same fashion as we did to read ipaimap.
132	 * By adding INOSPEREXT (32) to the inode number, we are telling
133	 * diReadSpecial that we are reading from the secondary aggregate
134	 * inode table.  This also creates a unique entry in the inode hash
135	 * table.
136	 */
137	if ((sbi->mntflag & JFS_BAD_SAIT) == 0) {
138		ipaimap2 = diReadSpecial(sb, AGGREGATE_I, 1);
139		if (!ipaimap2) {
140			jfs_err("jfs_mount: Failed to read AGGREGATE_I");
141			rc = -EIO;
142			goto err_umount_ipbmap;
143		}
144		sbi->ipaimap2 = ipaimap2;
145
146		jfs_info("jfs_mount: ipaimap2:0x%p", ipaimap2);
147
148		/*
149		 * initialize secondary aggregate inode allocation map
150		 */
151		if ((rc = diMount(ipaimap2))) {
152			jfs_err("jfs_mount: diMount(ipaimap2) failed, rc = %d",
153				rc);
154			goto err_ipaimap2;
155		}
156	} else
157		/* Secondary aggregate inode table is not valid */
158		sbi->ipaimap2 = NULL;
159
160	/*
161	 *	mount (the only/single) fileset
162	 */
163	/*
164	 * open fileset inode allocation map (aka fileset inode)
165	 */
166	ipimap = diReadSpecial(sb, FILESYSTEM_I, 0);
167	if (ipimap == NULL) {
168		jfs_err("jfs_mount: Failed to read FILESYSTEM_I");
169		/* open fileset secondary inode allocation map */
170		rc = -EIO;
171		goto err_umount_ipaimap2;
172	}
173	jfs_info("jfs_mount: ipimap:0x%p", ipimap);
174
175	/* initialize fileset inode allocation map */
176	if ((rc = diMount(ipimap))) {
177		jfs_err("jfs_mount: diMount failed w/rc = %d", rc);
178		goto err_ipimap;
179	}
180
181	/* map further access of per fileset inodes by the fileset inode */
182	sbi->ipimap = ipimap;
183
184	return rc;
185
186	/*
187	 *	unwind on error
188	 */
189err_ipimap:
190	/* close fileset inode allocation map inode */
191	diFreeSpecial(ipimap);
192err_umount_ipaimap2:
193	/* close secondary aggregate inode allocation map */
194	if (ipaimap2)
195		diUnmount(ipaimap2, 1);
196err_ipaimap2:
197	/* close aggregate inodes */
198	if (ipaimap2)
199		diFreeSpecial(ipaimap2);
200err_umount_ipbmap:	/* close aggregate block allocation map */
201	dbUnmount(ipbmap, 1);
202err_ipbmap:		/* close aggregate inodes */
203	diFreeSpecial(ipbmap);
204err_umount_ipaimap:	/* close aggregate inode allocation map */
205	diUnmount(ipaimap, 1);
206err_ipaimap:		/* close aggregate inodes */
207	diFreeSpecial(ipaimap);
208out:
209	if (rc)
210		jfs_err("Mount JFS Failure: %d", rc);
211
212	return rc;
213}
214
215/*
216 * NAME:	jfs_mount_rw(sb, remount)
217 *
218 * FUNCTION:	Completes read-write mount, or remounts read-only volume
219 *		as read-write
220 */
221int jfs_mount_rw(struct super_block *sb, int remount)
222{
223	struct jfs_sb_info *sbi = JFS_SBI(sb);
224	int rc;
225
226	/*
227	 * If we are re-mounting a previously read-only volume, we want to
228	 * re-read the inode and block maps, since fsck.jfs may have updated
229	 * them.
230	 */
231	if (remount) {
232		if (chkSuper(sb) || (sbi->state != FM_CLEAN))
233			return -EINVAL;
234
235		truncate_inode_pages(sbi->ipimap->i_mapping, 0);
236		truncate_inode_pages(sbi->ipbmap->i_mapping, 0);
237		diUnmount(sbi->ipimap, 1);
238		if ((rc = diMount(sbi->ipimap))) {
239			jfs_err("jfs_mount_rw: diMount failed!");
240			return rc;
241		}
242
243		dbUnmount(sbi->ipbmap, 1);
244		if ((rc = dbMount(sbi->ipbmap))) {
245			jfs_err("jfs_mount_rw: dbMount failed!");
246			return rc;
247		}
248	}
249
250	/*
251	 * open/initialize log
252	 */
253	if ((rc = lmLogOpen(sb)))
254		return rc;
255
256	/*
257	 * update file system superblock;
258	 */
259	if ((rc = updateSuper(sb, FM_MOUNT))) {
260		jfs_err("jfs_mount: updateSuper failed w/rc = %d", rc);
261		lmLogClose(sb);
262		return rc;
263	}
264
265	/*
266	 * write MOUNT log record of the file system
267	 */
268	logMOUNT(sb);
269
270	return rc;
271}
272
273/*
274 *	chkSuper()
275 *
276 * validate the superblock of the file system to be mounted and
277 * get the file system parameters.
278 *
279 * returns
280 *	0 with fragsize set if check successful
281 *	error code if not successful
282 */
283static int chkSuper(struct super_block *sb)
284{
285	int rc = 0;
286	struct jfs_sb_info *sbi = JFS_SBI(sb);
287	struct jfs_superblock *j_sb;
288	struct buffer_head *bh;
289	int AIM_bytesize, AIT_bytesize;
290	int expected_AIM_bytesize, expected_AIT_bytesize;
291	s64 AIM_byte_addr, AIT_byte_addr, fsckwsp_addr;
292	s64 byte_addr_diff0, byte_addr_diff1;
293	s32 bsize;
294
295	if ((rc = readSuper(sb, &bh)))
296		return rc;
297	j_sb = (struct jfs_superblock *)bh->b_data;
298
299	/*
300	 * validate superblock
301	 */
302	/* validate fs signature */
303	if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||
304	    le32_to_cpu(j_sb->s_version) > JFS_VERSION) {
305		rc = -EINVAL;
306		goto out;
307	}
308
309	bsize = le32_to_cpu(j_sb->s_bsize);
310#ifdef _JFS_4K
311	if (bsize != PSIZE) {
312		jfs_err("Currently only 4K block size supported!");
313		rc = -EINVAL;
314		goto out;
315	}
316#endif				/* _JFS_4K */
317
318	jfs_info("superblock: flag:0x%08x state:0x%08x size:0x%Lx",
319		 le32_to_cpu(j_sb->s_flag), le32_to_cpu(j_sb->s_state),
320		 (unsigned long long) le64_to_cpu(j_sb->s_size));
321
322	/* validate the descriptors for Secondary AIM and AIT */
323	if ((j_sb->s_flag & cpu_to_le32(JFS_BAD_SAIT)) !=
324	    cpu_to_le32(JFS_BAD_SAIT)) {
325		expected_AIM_bytesize = 2 * PSIZE;
326		AIM_bytesize = lengthPXD(&(j_sb->s_aim2)) * bsize;
327		expected_AIT_bytesize = 4 * PSIZE;
328		AIT_bytesize = lengthPXD(&(j_sb->s_ait2)) * bsize;
329		AIM_byte_addr = addressPXD(&(j_sb->s_aim2)) * bsize;
330		AIT_byte_addr = addressPXD(&(j_sb->s_ait2)) * bsize;
331		byte_addr_diff0 = AIT_byte_addr - AIM_byte_addr;
332		fsckwsp_addr = addressPXD(&(j_sb->s_fsckpxd)) * bsize;
333		byte_addr_diff1 = fsckwsp_addr - AIT_byte_addr;
334		if ((AIM_bytesize != expected_AIM_bytesize) ||
335		    (AIT_bytesize != expected_AIT_bytesize) ||
336		    (byte_addr_diff0 != AIM_bytesize) ||
337		    (byte_addr_diff1 <= AIT_bytesize))
338			j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);
339	}
340
341	if ((j_sb->s_flag & cpu_to_le32(JFS_GROUPCOMMIT)) !=
342	    cpu_to_le32(JFS_GROUPCOMMIT))
343		j_sb->s_flag |= cpu_to_le32(JFS_GROUPCOMMIT);
344
345	/* validate fs state */
346	if (j_sb->s_state != cpu_to_le32(FM_CLEAN) &&
347	    !sb_rdonly(sb)) {
348		jfs_err("jfs_mount: Mount Failure: File System Dirty.");
349		rc = -EINVAL;
350		goto out;
351	}
352
353	sbi->state = le32_to_cpu(j_sb->s_state);
354	sbi->mntflag = le32_to_cpu(j_sb->s_flag);
355
356	/*
357	 * JFS always does I/O by 4K pages.  Don't tell the buffer cache
358	 * that we use anything else (leave s_blocksize alone).
359	 */
360	sbi->bsize = bsize;
361	sbi->l2bsize = le16_to_cpu(j_sb->s_l2bsize);
362
363	/* check some fields for possible corruption */
364	if (sbi->l2bsize != ilog2((u32)bsize) ||
365	    j_sb->pad != 0 ||
366	    le32_to_cpu(j_sb->s_state) > FM_STATE_MAX) {
367		rc = -EINVAL;
368		jfs_err("jfs_mount: Mount Failure: superblock is corrupt!");
369		goto out;
370	}
371
372	/*
373	 * For now, ignore s_pbsize, l2bfactor.  All I/O going through buffer
374	 * cache.
375	 */
376	sbi->nbperpage = PSIZE >> sbi->l2bsize;
377	sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;
378	sbi->l2niperblk = sbi->l2bsize - L2DISIZE;
379	if (sbi->mntflag & JFS_INLINELOG)
380		sbi->logpxd = j_sb->s_logpxd;
381	else {
382		sbi->logdev = new_decode_dev(le32_to_cpu(j_sb->s_logdev));
383		uuid_copy(&sbi->uuid, &j_sb->s_uuid);
384		uuid_copy(&sbi->loguuid, &j_sb->s_loguuid);
385	}
386	sbi->fsckpxd = j_sb->s_fsckpxd;
387	sbi->ait2 = j_sb->s_ait2;
388
389      out:
390	brelse(bh);
391	return rc;
392}
393
394
395/*
396 *	updateSuper()
397 *
398 * update synchronously superblock if it is mounted read-write.
399 */
400int updateSuper(struct super_block *sb, uint state)
401{
402	struct jfs_superblock *j_sb;
403	struct jfs_sb_info *sbi = JFS_SBI(sb);
404	struct buffer_head *bh;
405	int rc;
406
407	if (sbi->flag & JFS_NOINTEGRITY) {
408		if (state == FM_DIRTY) {
409			sbi->p_state = state;
410			return 0;
411		} else if (state == FM_MOUNT) {
412			sbi->p_state = sbi->state;
413			state = FM_DIRTY;
414		} else if (state == FM_CLEAN) {
415			state = sbi->p_state;
416		} else
417			jfs_err("updateSuper: bad state");
418	} else if (sbi->state == FM_DIRTY)
419		return 0;
420
421	if ((rc = readSuper(sb, &bh)))
422		return rc;
423
424	j_sb = (struct jfs_superblock *)bh->b_data;
425
426	j_sb->s_state = cpu_to_le32(state);
427	sbi->state = state;
428
429	if (state == FM_MOUNT) {
430		/* record log's dev_t and mount serial number */
431		j_sb->s_logdev = cpu_to_le32(new_encode_dev(sbi->log->bdev->bd_dev));
432		j_sb->s_logserial = cpu_to_le32(sbi->log->serial);
433	} else if (state == FM_CLEAN) {
434		/*
435		 * If this volume is shared with OS/2, OS/2 will need to
436		 * recalculate DASD usage, since we don't deal with it.
437		 */
438		if (j_sb->s_flag & cpu_to_le32(JFS_DASD_ENABLED))
439			j_sb->s_flag |= cpu_to_le32(JFS_DASD_PRIME);
440	}
441
442	mark_buffer_dirty(bh);
443	sync_dirty_buffer(bh);
444	brelse(bh);
445
446	return 0;
447}
448
449
450/*
451 *	readSuper()
452 *
453 * read superblock by raw sector address
454 */
455int readSuper(struct super_block *sb, struct buffer_head **bpp)
456{
457	/* read in primary superblock */
458	*bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);
459	if (*bpp)
460		return 0;
461
462	/* read in secondary/replicated superblock */
463	*bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
464	if (*bpp)
465		return 0;
466
467	return -EIO;
468}
469
470
471/*
472 *	logMOUNT()
473 *
474 * function: write a MOUNT log record for file system.
475 *
476 * MOUNT record keeps logredo() from processing log records
477 * for this file system past this point in log.
478 * it is harmless if mount fails.
479 *
480 * note: MOUNT record is at aggregate level, not at fileset level,
481 * since log records of previous mounts of a fileset
482 * (e.g., AFTER record of extent allocation) have to be processed
483 * to update block allocation map at aggregate level.
484 */
485static int logMOUNT(struct super_block *sb)
486{
487	struct jfs_log *log = JFS_SBI(sb)->log;
488	struct lrd lrd;
489
490	lrd.logtid = 0;
491	lrd.backchain = 0;
492	lrd.type = cpu_to_le16(LOG_MOUNT);
493	lrd.length = 0;
494	lrd.aggregate = cpu_to_le32(new_encode_dev(sb->s_bdev->bd_dev));
495	lmLog(log, NULL, &lrd, NULL);
496
497	return 0;
498}
499