1 files changed, 500 insertions, 0 deletions

diff --git a/fs/jfs/jfs_mount.c b/fs/jfs/jfs_mount.c
new file mode 100644
index 0000000000..b83aae56a1
--- /dev/null
+++ b/fs/jfs/jfs_mount.c
@@ -0,0 +1,500 @@
+// 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 <linux/blkdev.h>
+#include <linux/log2.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 out;
+	}
+
+	ipaimap = diReadSpecial(sb, AGGREGATE_I, 0);
+	if (ipaimap == NULL) {
+		jfs_err("jfs_mount: Failed to read AGGREGATE_I");
+		rc = -EIO;
+		goto out;
+	}
+	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 err_ipaimap;
+	}
+
+	/*
+	 * open aggregate block allocation map
+	 */
+	ipbmap = diReadSpecial(sb, BMAP_I, 0);
+	if (ipbmap == NULL) {
+		rc = -EIO;
+		goto err_umount_ipaimap;
+	}
+
+	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 err_ipbmap;
+	}
+
+	/*
+	 * 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 err_umount_ipbmap;
+		}
+		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 err_ipaimap2;
+		}
+	} 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 err_umount_ipaimap2;
+	}
+	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 err_ipimap;
+	}
+
+	return rc;
+
+	/*
+	 *	unwind on error
+	 */
+err_ipimap:
+	/* close fileset inode allocation map inode */
+	diFreeSpecial(ipimap);
+err_umount_ipaimap2:
+	/* close secondary aggregate inode allocation map */
+	if (ipaimap2)
+		diUnmount(ipaimap2, 1);
+err_ipaimap2:
+	/* close aggregate inodes */
+	if (ipaimap2)
+		diFreeSpecial(ipaimap2);
+err_umount_ipbmap:	/* close aggregate block allocation map */
+	dbUnmount(ipbmap, 1);
+err_ipbmap:		/* close aggregate inodes */
+	diFreeSpecial(ipbmap);
+err_umount_ipaimap:	/* close aggregate inode allocation map */
+	diUnmount(ipaimap, 1);
+err_ipaimap:		/* close aggregate inodes */
+	diFreeSpecial(ipaimap);
+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);
+
+		IWRITE_LOCK(sbi->ipimap, RDWRLOCK_IMAP);
+		diUnmount(sbi->ipimap, 1);
+		if ((rc = diMount(sbi->ipimap))) {
+			IWRITE_UNLOCK(sbi->ipimap);
+			jfs_err("jfs_mount_rw: diMount failed!");
+			return rc;
+		}
+		IWRITE_UNLOCK(sbi->ipimap);
+
+		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);
+	if (bsize != PSIZE) {
+		jfs_err("Only 4K block size supported!");
+		rc = -EINVAL;
+		goto out;
+	}
+
+	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);
+
+	/* check some fields for possible corruption */
+	if (sbi->l2bsize != ilog2((u32)bsize) ||
+	    j_sb->pad != 0 ||
+	    le32_to_cpu(j_sb->s_state) > FM_STATE_MAX) {
+		rc = -EINVAL;
+		jfs_err("jfs_mount: Mount Failure: superblock is corrupt!");
+		goto out;
+	}
+
+	/*
+	 * 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;
+}