[linux-2.6-block.git] / fs / jfs / jfs_mount.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) International Business Machines Corp., 2000-2004
 */

/*
 * Module: jfs_mount.c
 *
 * note: file system in transition to aggregate/fileset:
 *
 * file system mount is interpreted as the mount of aggregate,
 * if not already mounted, and mount of the single/only fileset in
 * the aggregate;
 *
 * a file system/aggregate is represented by an internal inode
 * (aka mount inode) initialized with aggregate superblock;
 * each vfs represents a fileset, and points to its "fileset inode
 * allocation map inode" (aka fileset inode):
 * (an aggregate itself is structured recursively as a filset:
 * an internal vfs is constructed and points to its "fileset inode
 * allocation map inode" (aka aggregate inode) where each inode
 * represents a fileset inode) so that inode number is mapped to
 * on-disk inode in uniform way at both aggregate and fileset level;
 *
 * each vnode/inode of a fileset is linked to its vfs (to facilitate
 * per fileset inode operations, e.g., unmount of a fileset, etc.);
 * each inode points to the mount inode (to facilitate access to
 * per aggregate information, e.g., block size, etc.) as well as
 * its file set inode.
 *
 *   aggregate
 *   ipmnt
 *   mntvfs -> fileset ipimap+ -> aggregate ipbmap -> aggregate ipaimap;
 *             fileset vfs     -> vp(1) <-> ... <-> vp(n) <->vproot;
 */

#include <linux/fs.h>
#include <linux/buffer_head.h>

#include "jfs_incore.h"
#include "jfs_filsys.h"
#include "jfs_superblock.h"
#include "jfs_dmap.h"
#include "jfs_imap.h"
#include "jfs_metapage.h"
#include "jfs_debug.h"


/*
 * forward references
 */
static int chkSuper(struct super_block *);
static int logMOUNT(struct super_block *sb);

/*
 * NAME:	jfs_mount(sb)
 *
 * FUNCTION:	vfs_mount()
 *
 * PARAMETER:	sb	- super block
 *
 * RETURN:	-EBUSY	- device already mounted or open for write
 *		-EBUSY	- cvrdvp already mounted;
 *		-EBUSY	- mount table full
 *		-ENOTDIR- cvrdvp not directory on a device mount
 *		-ENXIO	- device open failure
 */
int jfs_mount(struct super_block *sb)
{
	int rc = 0;		/* Return code */
	struct jfs_sb_info *sbi = JFS_SBI(sb);
	struct inode *ipaimap = NULL;
	struct inode *ipaimap2 = NULL;
	struct inode *ipimap = NULL;
	struct inode *ipbmap = NULL;

	/*
	 * read/validate superblock
	 * (initialize mount inode from the superblock)
	 */
	if ((rc = chkSuper(sb))) {
		goto errout20;
	}

	ipaimap = diReadSpecial(sb, AGGREGATE_I, 0);
	if (ipaimap == NULL) {
		jfs_err("jfs_mount: Failed to read AGGREGATE_I");
		rc = -EIO;
		goto errout20;
	}
	sbi->ipaimap = ipaimap;

	jfs_info("jfs_mount: ipaimap:0x%p", ipaimap);

	/*
	 * initialize aggregate inode allocation map
	 */
	if ((rc = diMount(ipaimap))) {
		jfs_err("jfs_mount: diMount(ipaimap) failed w/rc = %d", rc);
		goto errout21;
	}

	/*
	 * open aggregate block allocation map
	 */
	ipbmap = diReadSpecial(sb, BMAP_I, 0);
	if (ipbmap == NULL) {
		rc = -EIO;
		goto errout22;
	}

	jfs_info("jfs_mount: ipbmap:0x%p", ipbmap);

	sbi->ipbmap = ipbmap;

	/*
	 * initialize aggregate block allocation map
	 */
	if ((rc = dbMount(ipbmap))) {
		jfs_err("jfs_mount: dbMount failed w/rc = %d", rc);
		goto errout22;
	}

	/*
	 * open the secondary aggregate inode allocation map
	 *
	 * This is a duplicate of the aggregate inode allocation map.
	 *
	 * hand craft a vfs in the same fashion as we did to read ipaimap.
	 * By adding INOSPEREXT (32) to the inode number, we are telling
	 * diReadSpecial that we are reading from the secondary aggregate
	 * inode table.  This also creates a unique entry in the inode hash
	 * table.
	 */
	if ((sbi->mntflag & JFS_BAD_SAIT) == 0) {
		ipaimap2 = diReadSpecial(sb, AGGREGATE_I, 1);
		if (!ipaimap2) {
			jfs_err("jfs_mount: Failed to read AGGREGATE_I");
			rc = -EIO;
			goto errout35;
		}
		sbi->ipaimap2 = ipaimap2;

		jfs_info("jfs_mount: ipaimap2:0x%p", ipaimap2);

		/*
		 * initialize secondary aggregate inode allocation map
		 */
		if ((rc = diMount(ipaimap2))) {
			jfs_err("jfs_mount: diMount(ipaimap2) failed, rc = %d",
				rc);
			goto errout35;
		}
	} else
		/* Secondary aggregate inode table is not valid */
		sbi->ipaimap2 = NULL;

	/*
	 *	mount (the only/single) fileset
	 */
	/*
	 * open fileset inode allocation map (aka fileset inode)
	 */
	ipimap = diReadSpecial(sb, FILESYSTEM_I, 0);
	if (ipimap == NULL) {
		jfs_err("jfs_mount: Failed to read FILESYSTEM_I");
		/* open fileset secondary inode allocation map */
		rc = -EIO;
		goto errout40;
	}
	jfs_info("jfs_mount: ipimap:0x%p", ipimap);

	/* map further access of per fileset inodes by the fileset inode */
	sbi->ipimap = ipimap;

	/* initialize fileset inode allocation map */
	if ((rc = diMount(ipimap))) {
		jfs_err("jfs_mount: diMount failed w/rc = %d", rc);
		goto errout41;
	}

	goto out;

	/*
	 *	unwind on error
	 */
      errout41:		/* close fileset inode allocation map inode */
	diFreeSpecial(ipimap);

      errout40:		/* fileset closed */

	/* close secondary aggregate inode allocation map */
	if (ipaimap2) {
		diUnmount(ipaimap2, 1);
		diFreeSpecial(ipaimap2);
	}

      errout35:

	/* close aggregate block allocation map */
	dbUnmount(ipbmap, 1);
	diFreeSpecial(ipbmap);

      errout22:		/* close aggregate inode allocation map */

	diUnmount(ipaimap, 1);

      errout21:		/* close aggregate inodes */
	diFreeSpecial(ipaimap);
      errout20:		/* aggregate closed */

      out:

	if (rc)
		jfs_err("Mount JFS Failure: %d", rc);

	return rc;
}

/*
 * NAME:	jfs_mount_rw(sb, remount)
 *
 * FUNCTION:	Completes read-write mount, or remounts read-only volume
 *		as read-write
 */
int jfs_mount_rw(struct super_block *sb, int remount)
{
	struct jfs_sb_info *sbi = JFS_SBI(sb);
	int rc;

	/*
	 * If we are re-mounting a previously read-only volume, we want to
	 * re-read the inode and block maps, since fsck.jfs may have updated
	 * them.
	 */
	if (remount) {
		if (chkSuper(sb) || (sbi->state != FM_CLEAN))
			return -EINVAL;

		truncate_inode_pages(sbi->ipimap->i_mapping, 0);
		truncate_inode_pages(sbi->ipbmap->i_mapping, 0);
		diUnmount(sbi->ipimap, 1);
		if ((rc = diMount(sbi->ipimap))) {
			jfs_err("jfs_mount_rw: diMount failed!");
			return rc;
		}

		dbUnmount(sbi->ipbmap, 1);
		if ((rc = dbMount(sbi->ipbmap))) {
			jfs_err("jfs_mount_rw: dbMount failed!");
			return rc;
		}
	}

	/*
	 * open/initialize log
	 */
	if ((rc = lmLogOpen(sb)))
		return rc;

	/*
	 * update file system superblock;
	 */
	if ((rc = updateSuper(sb, FM_MOUNT))) {
		jfs_err("jfs_mount: updateSuper failed w/rc = %d", rc);
		lmLogClose(sb);
		return rc;
	}

	/*
	 * write MOUNT log record of the file system
	 */
	logMOUNT(sb);

	return rc;
}

/*
 *	chkSuper()
 *
 * validate the superblock of the file system to be mounted and
 * get the file system parameters.
 *
 * returns
 *	0 with fragsize set if check successful
 *	error code if not successful
 */
static int chkSuper(struct super_block *sb)
{
	int rc = 0;
	struct jfs_sb_info *sbi = JFS_SBI(sb);
	struct jfs_superblock *j_sb;
	struct buffer_head *bh;
	int AIM_bytesize, AIT_bytesize;
	int expected_AIM_bytesize, expected_AIT_bytesize;
	s64 AIM_byte_addr, AIT_byte_addr, fsckwsp_addr;
	s64 byte_addr_diff0, byte_addr_diff1;
	s32 bsize;

	if ((rc = readSuper(sb, &bh)))
		return rc;
	j_sb = (struct jfs_superblock *)bh->b_data;

	/*
	 * validate superblock
	 */
	/* validate fs signature */
	if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||
	    le32_to_cpu(j_sb->s_version) > JFS_VERSION) {
		rc = -EINVAL;
		goto out;
	}

	bsize = le32_to_cpu(j_sb->s_bsize);
#ifdef _JFS_4K
	if (bsize != PSIZE) {
		jfs_err("Currently only 4K block size supported!");
		rc = -EINVAL;
		goto out;
	}
#endif				/* _JFS_4K */

	jfs_info("superblock: flag:0x%08x state:0x%08x size:0x%Lx",
		 le32_to_cpu(j_sb->s_flag), le32_to_cpu(j_sb->s_state),
		 (unsigned long long) le64_to_cpu(j_sb->s_size));

	/* validate the descriptors for Secondary AIM and AIT */
	if ((j_sb->s_flag & cpu_to_le32(JFS_BAD_SAIT)) !=
	    cpu_to_le32(JFS_BAD_SAIT)) {
		expected_AIM_bytesize = 2 * PSIZE;
		AIM_bytesize = lengthPXD(&(j_sb->s_aim2)) * bsize;
		expected_AIT_bytesize = 4 * PSIZE;
		AIT_bytesize = lengthPXD(&(j_sb->s_ait2)) * bsize;
		AIM_byte_addr = addressPXD(&(j_sb->s_aim2)) * bsize;
		AIT_byte_addr = addressPXD(&(j_sb->s_ait2)) * bsize;
		byte_addr_diff0 = AIT_byte_addr - AIM_byte_addr;
		fsckwsp_addr = addressPXD(&(j_sb->s_fsckpxd)) * bsize;
		byte_addr_diff1 = fsckwsp_addr - AIT_byte_addr;
		if ((AIM_bytesize != expected_AIM_bytesize) ||
		    (AIT_bytesize != expected_AIT_bytesize) ||
		    (byte_addr_diff0 != AIM_bytesize) ||
		    (byte_addr_diff1 <= AIT_bytesize))
			j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);
	}

	if ((j_sb->s_flag & cpu_to_le32(JFS_GROUPCOMMIT)) !=
	    cpu_to_le32(JFS_GROUPCOMMIT))
		j_sb->s_flag |= cpu_to_le32(JFS_GROUPCOMMIT);

	/* validate fs state */
	if (j_sb->s_state != cpu_to_le32(FM_CLEAN) &&
	    !sb_rdonly(sb)) {
		jfs_err("jfs_mount: Mount Failure: File System Dirty.");
		rc = -EINVAL;
		goto out;
	}

	sbi->state = le32_to_cpu(j_sb->s_state);
	sbi->mntflag = le32_to_cpu(j_sb->s_flag);

	/*
	 * JFS always does I/O by 4K pages.  Don't tell the buffer cache
	 * that we use anything else (leave s_blocksize alone).
	 */
	sbi->bsize = bsize;
	sbi->l2bsize = le16_to_cpu(j_sb->s_l2bsize);

	/*
	 * For now, ignore s_pbsize, l2bfactor.  All I/O going through buffer
	 * cache.
	 */
	sbi->nbperpage = PSIZE >> sbi->l2bsize;
	sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;
	sbi->l2niperblk = sbi->l2bsize - L2DISIZE;
	if (sbi->mntflag & JFS_INLINELOG)
		sbi->logpxd = j_sb->s_logpxd;
	else {
		sbi->logdev = new_decode_dev(le32_to_cpu(j_sb->s_logdev));
		uuid_copy(&sbi->uuid, &j_sb->s_uuid);
		uuid_copy(&sbi->loguuid, &j_sb->s_loguuid);
	}
	sbi->fsckpxd = j_sb->s_fsckpxd;
	sbi->ait2 = j_sb->s_ait2;

      out:
	brelse(bh);
	return rc;
}


/*
 *	updateSuper()
 *
 * update synchronously superblock if it is mounted read-write.
 */
int updateSuper(struct super_block *sb, uint state)
{
	struct jfs_superblock *j_sb;
	struct jfs_sb_info *sbi = JFS_SBI(sb);
	struct buffer_head *bh;
	int rc;

	if (sbi->flag & JFS_NOINTEGRITY) {
		if (state == FM_DIRTY) {
			sbi->p_state = state;
			return 0;
		} else if (state == FM_MOUNT) {
			sbi->p_state = sbi->state;
			state = FM_DIRTY;
		} else if (state == FM_CLEAN) {
			state = sbi->p_state;
		} else
			jfs_err("updateSuper: bad state");
	} else if (sbi->state == FM_DIRTY)
		return 0;

	if ((rc = readSuper(sb, &bh)))
		return rc;

	j_sb = (struct jfs_superblock *)bh->b_data;

	j_sb->s_state = cpu_to_le32(state);
	sbi->state = state;

	if (state == FM_MOUNT) {
		/* record log's dev_t and mount serial number */
		j_sb->s_logdev = cpu_to_le32(new_encode_dev(sbi->log->bdev->bd_dev));
		j_sb->s_logserial = cpu_to_le32(sbi->log->serial);
	} else if (state == FM_CLEAN) {
		/*
		 * If this volume is shared with OS/2, OS/2 will need to
		 * recalculate DASD usage, since we don't deal with it.
		 */
		if (j_sb->s_flag & cpu_to_le32(JFS_DASD_ENABLED))
			j_sb->s_flag |= cpu_to_le32(JFS_DASD_PRIME);
	}

	mark_buffer_dirty(bh);
	sync_dirty_buffer(bh);
	brelse(bh);

	return 0;
}


/*
 *	readSuper()
 *
 * read superblock by raw sector address
 */
int readSuper(struct super_block *sb, struct buffer_head **bpp)
{
	/* read in primary superblock */
	*bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);
	if (*bpp)
		return 0;

	/* read in secondary/replicated superblock */
	*bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
	if (*bpp)
		return 0;

	return -EIO;
}


/*
 *	logMOUNT()
 *
 * function: write a MOUNT log record for file system.
 *
 * MOUNT record keeps logredo() from processing log records
 * for this file system past this point in log.
 * it is harmless if mount fails.
 *
 * note: MOUNT record is at aggregate level, not at fileset level,
 * since log records of previous mounts of a fileset
 * (e.g., AFTER record of extent allocation) have to be processed
 * to update block allocation map at aggregate level.
 */
static int logMOUNT(struct super_block *sb)
{
	struct jfs_log *log = JFS_SBI(sb)->log;
	struct lrd lrd;

	lrd.logtid = 0;
	lrd.backchain = 0;
	lrd.type = cpu_to_le16(LOG_MOUNT);
	lrd.length = 0;
	lrd.aggregate = cpu_to_le32(new_encode_dev(sb->s_bdev->bd_dev));
	lmLog(log, NULL, &lrd, NULL);

	return 0;
}
Commit	Line	Data
1a59d1b8	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
1da177e4 LT	3	* Copyright (C) International Business Machines Corp., 2000-2004
1da177e4 LT	4	*/
	5
	6	/*
	7	* Module: jfs_mount.c
	8	*
	9	* note: file system in transition to aggregate/fileset:
	10	*
63f83c9f DK	11	* file system mount is interpreted as the mount of aggregate,
63f83c9f DK	12	* if not already mounted, and mount of the single/only fileset in
1da177e4 LT	13	* the aggregate;
	14	*
	15	* a file system/aggregate is represented by an internal inode
	16	* (aka mount inode) initialized with aggregate superblock;
63f83c9f	17	* each vfs represents a fileset, and points to its "fileset inode
1da177e4	18	* allocation map inode" (aka fileset inode):
63f83c9f DK	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
1da177e4 LT	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	*
63f83c9f	31	* aggregate
1da177e4 LT	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	{
f720e3ba	70	int rc = 0; /* Return code */
1da177e4 LT	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	/*
63f83c9f	78	* read/validate superblock
1da177e4 LT	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) {
426d3107	87	jfs_err("jfs_mount: Failed to read AGGREGATE_I");
1da177e4 LT	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);
09aaa749	137	if (!ipaimap2) {
426d3107	138	jfs_err("jfs_mount: Failed to read AGGREGATE_I");
1da177e4 LT	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	/*
f720e3ba	159	* mount (the only/single) fileset
1da177e4 LT	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	/*
f720e3ba	185	* unwind on error
1da177e4 LT	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	{
63f83c9f	228	struct jfs_sb_info *sbi = JFS_SBI(sb);
1da177e4 LT	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
1da177e4 LT	275	return rc;
	276	}
	277
	278	/*
	279	* chkSuper()
	280	*
63f83c9f	281	* validate the superblock of the file system to be mounted and
1da177e4 LT	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) &&
bc98a42c	352	!sb_rdonly(sb)) {
1da177e4 LT	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));
2e3bc612 AS	379	uuid_copy(&sbi->uuid, &j_sb->s_uuid);
2e3bc612 AS	380	uuid_copy(&sbi->loguuid, &j_sb->s_loguuid);
1da177e4 LT	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;
63f83c9f	416
1da177e4 LT	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	*
63f83c9f	476	* note: MOUNT record is at aggregate level, not at fileset level,
1da177e4	477	* since log records of previous mounts of a fileset
63f83c9f	478	* (e.g., AFTER record of extent allocation) have to be processed
1da177e4 LT	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	}