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
238		IWRITE_LOCK(sbi->ipimap, RDWRLOCK_IMAP);
239		diUnmount(sbi->ipimap, 1);
240		if ((rc = diMount(sbi->ipimap))) {
241			IWRITE_UNLOCK(sbi->ipimap);
242			jfs_err("jfs_mount_rw: diMount failed!");
243			return rc;
244		}
245		IWRITE_UNLOCK(sbi->ipimap);
246
247		dbUnmount(sbi->ipbmap, 1);
248		if ((rc = dbMount(sbi->ipbmap))) {
249			jfs_err("jfs_mount_rw: dbMount failed!");
250			return rc;
251		}
252	}
253
254	/*
255	 * open/initialize log
256	 */
257	if ((rc = lmLogOpen(sb)))
258		return rc;
259
260	/*
261	 * update file system superblock;
262	 */
263	if ((rc = updateSuper(sb, FM_MOUNT))) {
264		jfs_err("jfs_mount: updateSuper failed w/rc = %d", rc);
265		lmLogClose(sb);
266		return rc;
267	}
268
269	/*
270	 * write MOUNT log record of the file system
271	 */
272	logMOUNT(sb);
273
274	return rc;
275}
276
277/*
278 *	chkSuper()
279 *
280 * validate the superblock of the file system to be mounted and
281 * get the file system parameters.
282 *
283 * returns
284 *	0 with fragsize set if check successful
285 *	error code if not successful
286 */
287static int chkSuper(struct super_block *sb)
288{
289	int rc = 0;
290	struct jfs_sb_info *sbi = JFS_SBI(sb);
291	struct jfs_superblock *j_sb;
292	struct buffer_head *bh;
293	int AIM_bytesize, AIT_bytesize;
294	int expected_AIM_bytesize, expected_AIT_bytesize;
295	s64 AIM_byte_addr, AIT_byte_addr, fsckwsp_addr;
296	s64 byte_addr_diff0, byte_addr_diff1;
297	s32 bsize;
298
299	if ((rc = readSuper(sb, &bh)))
300		return rc;
301	j_sb = (struct jfs_superblock *)bh->b_data;
302
303	/*
304	 * validate superblock
305	 */
306	/* validate fs signature */
307	if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||
308	    le32_to_cpu(j_sb->s_version) > JFS_VERSION) {
309		rc = -EINVAL;
310		goto out;
311	}
312
313	bsize = le32_to_cpu(j_sb->s_bsize);
314	if (bsize != PSIZE) {
315		jfs_err("Only 4K block size supported!");
316		rc = -EINVAL;
317		goto out;
318	}
319
320	jfs_info("superblock: flag:0x%08x state:0x%08x size:0x%Lx",
321		 le32_to_cpu(j_sb->s_flag), le32_to_cpu(j_sb->s_state),
322		 (unsigned long long) le64_to_cpu(j_sb->s_size));
323
324	/* validate the descriptors for Secondary AIM and AIT */
325	if ((j_sb->s_flag & cpu_to_le32(JFS_BAD_SAIT)) !=
326	    cpu_to_le32(JFS_BAD_SAIT)) {
327		expected_AIM_bytesize = 2 * PSIZE;
328		AIM_bytesize = lengthPXD(&(j_sb->s_aim2)) * bsize;
329		expected_AIT_bytesize = 4 * PSIZE;
330		AIT_bytesize = lengthPXD(&(j_sb->s_ait2)) * bsize;
331		AIM_byte_addr = addressPXD(&(j_sb->s_aim2)) * bsize;
332		AIT_byte_addr = addressPXD(&(j_sb->s_ait2)) * bsize;
333		byte_addr_diff0 = AIT_byte_addr - AIM_byte_addr;
334		fsckwsp_addr = addressPXD(&(j_sb->s_fsckpxd)) * bsize;
335		byte_addr_diff1 = fsckwsp_addr - AIT_byte_addr;
336		if ((AIM_bytesize != expected_AIM_bytesize) ||
337		    (AIT_bytesize != expected_AIT_bytesize) ||
338		    (byte_addr_diff0 != AIM_bytesize) ||
339		    (byte_addr_diff1 <= AIT_bytesize))
340			j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);
341	}
342
343	if ((j_sb->s_flag & cpu_to_le32(JFS_GROUPCOMMIT)) !=
344	    cpu_to_le32(JFS_GROUPCOMMIT))
345		j_sb->s_flag |= cpu_to_le32(JFS_GROUPCOMMIT);
346
347	/* validate fs state */
348	if (j_sb->s_state != cpu_to_le32(FM_CLEAN) &&
349	    !sb_rdonly(sb)) {
350		jfs_err("jfs_mount: Mount Failure: File System Dirty.");
351		rc = -EINVAL;
352		goto out;
353	}
354
355	sbi->state = le32_to_cpu(j_sb->s_state);
356	sbi->mntflag = le32_to_cpu(j_sb->s_flag);
357
358	/*
359	 * JFS always does I/O by 4K pages.  Don't tell the buffer cache
360	 * that we use anything else (leave s_blocksize alone).
361	 */
362	sbi->bsize = bsize;
363	sbi->l2bsize = le16_to_cpu(j_sb->s_l2bsize);
364
365	/* check some fields for possible corruption */
366	if (sbi->l2bsize != ilog2((u32)bsize) ||
367	    j_sb->pad != 0 ||
368	    le32_to_cpu(j_sb->s_state) > FM_STATE_MAX) {
369		rc = -EINVAL;
370		jfs_err("jfs_mount: Mount Failure: superblock is corrupt!");
371		goto out;
372	}
373
374	/*
375	 * For now, ignore s_pbsize, l2bfactor.  All I/O going through buffer
376	 * cache.
377	 */
378	sbi->nbperpage = PSIZE >> sbi->l2bsize;
379	sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;
380	sbi->l2niperblk = sbi->l2bsize - L2DISIZE;
381	if (sbi->mntflag & JFS_INLINELOG)
382		sbi->logpxd = j_sb->s_logpxd;
383	else {
384		sbi->logdev = new_decode_dev(le32_to_cpu(j_sb->s_logdev));
385		uuid_copy(&sbi->uuid, &j_sb->s_uuid);
386		uuid_copy(&sbi->loguuid, &j_sb->s_loguuid);
387	}
388	sbi->fsckpxd = j_sb->s_fsckpxd;
389	sbi->ait2 = j_sb->s_ait2;
390
391      out:
392	brelse(bh);
393	return rc;
394}
395
396
397/*
398 *	updateSuper()
399 *
400 * update synchronously superblock if it is mounted read-write.
401 */
402int updateSuper(struct super_block *sb, uint state)
403{
404	struct jfs_superblock *j_sb;
405	struct jfs_sb_info *sbi = JFS_SBI(sb);
406	struct buffer_head *bh;
407	int rc;
408
409	if (sbi->flag & JFS_NOINTEGRITY) {
410		if (state == FM_DIRTY) {
411			sbi->p_state = state;
412			return 0;
413		} else if (state == FM_MOUNT) {
414			sbi->p_state = sbi->state;
415			state = FM_DIRTY;
416		} else if (state == FM_CLEAN) {
417			state = sbi->p_state;
418		} else
419			jfs_err("updateSuper: bad state");
420	} else if (sbi->state == FM_DIRTY)
421		return 0;
422
423	if ((rc = readSuper(sb, &bh)))
424		return rc;
425
426	j_sb = (struct jfs_superblock *)bh->b_data;
427
428	j_sb->s_state = cpu_to_le32(state);
429	sbi->state = state;
430
431	if (state == FM_MOUNT) {
432		/* record log's dev_t and mount serial number */
433		j_sb->s_logdev = cpu_to_le32(
434			new_encode_dev(file_bdev(sbi->log->bdev_file)->bd_dev));
435		j_sb->s_logserial = cpu_to_le32(sbi->log->serial);
436	} else if (state == FM_CLEAN) {
437		/*
438		 * If this volume is shared with OS/2, OS/2 will need to
439		 * recalculate DASD usage, since we don't deal with it.
440		 */
441		if (j_sb->s_flag & cpu_to_le32(JFS_DASD_ENABLED))
442			j_sb->s_flag |= cpu_to_le32(JFS_DASD_PRIME);
443	}
444
445	mark_buffer_dirty(bh);
446	sync_dirty_buffer(bh);
447	brelse(bh);
448
449	return 0;
450}
451
452
453/*
454 *	readSuper()
455 *
456 * read superblock by raw sector address
457 */
458int readSuper(struct super_block *sb, struct buffer_head **bpp)
459{
460	/* read in primary superblock */
461	*bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);
462	if (*bpp)
463		return 0;
464
465	/* read in secondary/replicated superblock */
466	*bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
467	if (*bpp)
468		return 0;
469
470	return -EIO;
471}
472
473
474/*
475 *	logMOUNT()
476 *
477 * function: write a MOUNT log record for file system.
478 *
479 * MOUNT record keeps logredo() from processing log records
480 * for this file system past this point in log.
481 * it is harmless if mount fails.
482 *
483 * note: MOUNT record is at aggregate level, not at fileset level,
484 * since log records of previous mounts of a fileset
485 * (e.g., AFTER record of extent allocation) have to be processed
486 * to update block allocation map at aggregate level.
487 */
488static int logMOUNT(struct super_block *sb)
489{
490	struct jfs_log *log = JFS_SBI(sb)->log;
491	struct lrd lrd;
492
493	lrd.logtid = 0;
494	lrd.backchain = 0;
495	lrd.type = cpu_to_le16(LOG_MOUNT);
496	lrd.length = 0;
497	lrd.aggregate = cpu_to_le32(new_encode_dev(sb->s_bdev->bd_dev));
498	lmLog(log, NULL, &lrd, NULL);
499
500	return 0;
501}
502