1 files changed, 390 insertions, 188 deletions

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index b4d1d649063..b117fcf2c4f 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -40,6 +40,44 @@
 #define DO 0
 #define UNDO 1
 
+static const u32 gfs2_old_fs_formats[] = {
+        0
+};
+
+static const u32 gfs2_old_multihost_formats[] = {
+        0
+};
+
+/**
+ * gfs2_tune_init - Fill a gfs2_tune structure with default values
+ * @gt: tune
+ *
+ */
+
+static void gfs2_tune_init(struct gfs2_tune *gt)
+{
+	spin_lock_init(&gt->gt_spin);
+
+	gt->gt_demote_secs = 300;
+	gt->gt_incore_log_blocks = 1024;
+	gt->gt_log_flush_secs = 60;
+	gt->gt_recoverd_secs = 60;
+	gt->gt_logd_secs = 1;
+	gt->gt_quotad_secs = 5;
+	gt->gt_quota_simul_sync = 64;
+	gt->gt_quota_warn_period = 10;
+	gt->gt_quota_scale_num = 1;
+	gt->gt_quota_scale_den = 1;
+	gt->gt_quota_cache_secs = 300;
+	gt->gt_quota_quantum = 60;
+	gt->gt_new_files_jdata = 0;
+	gt->gt_max_readahead = 1 << 18;
+	gt->gt_stall_secs = 600;
+	gt->gt_complain_secs = 10;
+	gt->gt_statfs_quantum = 30;
+	gt->gt_statfs_slow = 0;
+}
+
 static struct gfs2_sbd *init_sbd(struct super_block *sb)
 {
 	struct gfs2_sbd *sdp;
@@ -96,21 +134,271 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
 	return sdp;
 }
 
-static void init_vfs(struct super_block *sb, unsigned noatime)
+
+/**
+ * gfs2_check_sb - Check superblock
+ * @sdp: the filesystem
+ * @sb: The superblock
+ * @silent: Don't print a message if the check fails
+ *
+ * Checks the version code of the FS is one that we understand how to
+ * read and that the sizes of the various on-disk structures have not
+ * changed.
+ */
+
+static int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb_host *sb, int silent)
 {
-	struct gfs2_sbd *sdp = sb->s_fs_info;
+	unsigned int x;
 
-	sb->s_magic = GFS2_MAGIC;
-	sb->s_op = &gfs2_super_ops;
-	sb->s_export_op = &gfs2_export_ops;
-	sb->s_time_gran = 1;
-	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	if (sb->sb_magic != GFS2_MAGIC ||
+	    sb->sb_type != GFS2_METATYPE_SB) {
+		if (!silent)
+			printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
+		return -EINVAL;
+	}
+
+	/*  If format numbers match exactly, we're done.  */
+
+	if (sb->sb_fs_format == GFS2_FORMAT_FS &&
+	    sb->sb_multihost_format == GFS2_FORMAT_MULTI)
+		return 0;
+
+	if (sb->sb_fs_format != GFS2_FORMAT_FS) {
+		for (x = 0; gfs2_old_fs_formats[x]; x++)
+			if (gfs2_old_fs_formats[x] == sb->sb_fs_format)
+				break;
+
+		if (!gfs2_old_fs_formats[x]) {
+			printk(KERN_WARNING
+			       "GFS2: code version (%u, %u) is incompatible "
+			       "with ondisk format (%u, %u)\n",
+			       GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
+			       sb->sb_fs_format, sb->sb_multihost_format);
+			printk(KERN_WARNING
+			       "GFS2: I don't know how to upgrade this FS\n");
+			return -EINVAL;
+		}
+	}
+
+	if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
+		for (x = 0; gfs2_old_multihost_formats[x]; x++)
+			if (gfs2_old_multihost_formats[x] ==
+			    sb->sb_multihost_format)
+				break;
+
+		if (!gfs2_old_multihost_formats[x]) {
+			printk(KERN_WARNING
+			       "GFS2: code version (%u, %u) is incompatible "
+			       "with ondisk format (%u, %u)\n",
+			       GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
+			       sb->sb_fs_format, sb->sb_multihost_format);
+			printk(KERN_WARNING
+			       "GFS2: I don't know how to upgrade this FS\n");
+			return -EINVAL;
+		}
+	}
+
+	if (!sdp->sd_args.ar_upgrade) {
+		printk(KERN_WARNING
+		       "GFS2: code version (%u, %u) is incompatible "
+		       "with ondisk format (%u, %u)\n",
+		       GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
+		       sb->sb_fs_format, sb->sb_multihost_format);
+		printk(KERN_INFO
+		       "GFS2: Use the \"upgrade\" mount option to upgrade "
+		       "the FS\n");
+		printk(KERN_INFO "GFS2: See the manual for more details\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void end_bio_io_page(struct bio *bio, int error)
+{
+	struct page *page = bio->bi_private;
 
-	if (sb->s_flags & (MS_NOATIME | MS_NODIRATIME))
-		set_bit(noatime, &sdp->sd_flags);
+	if (!error)
+		SetPageUptodate(page);
+	else
+		printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
+	unlock_page(page);
+}
+
+static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf)
+{
+	const struct gfs2_sb *str = buf;
+
+	sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
+	sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
+	sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
+	sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
+	sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
+	sb->sb_bsize = be32_to_cpu(str->sb_bsize);
+	sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
+	sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
+	sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
+	sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
+	sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
+
+	memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
+	memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
+}
+
+/**
+ * gfs2_read_super - Read the gfs2 super block from disk
+ * @sdp: The GFS2 super block
+ * @sector: The location of the super block
+ * @error: The error code to return
+ *
+ * This uses the bio functions to read the super block from disk
+ * because we want to be 100% sure that we never read cached data.
+ * A super block is read twice only during each GFS2 mount and is
+ * never written to by the filesystem. The first time its read no
+ * locks are held, and the only details which are looked at are those
+ * relating to the locking protocol. Once locking is up and working,
+ * the sb is read again under the lock to establish the location of
+ * the master directory (contains pointers to journals etc) and the
+ * root directory.
+ *
+ * Returns: 0 on success or error
+ */
+
+static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector)
+{
+	struct super_block *sb = sdp->sd_vfs;
+	struct gfs2_sb *p;
+	struct page *page;
+	struct bio *bio;
+
+	page = alloc_page(GFP_NOFS);
+	if (unlikely(!page))
+		return -ENOBUFS;
+
+	ClearPageUptodate(page);
+	ClearPageDirty(page);
+	lock_page(page);
+
+	bio = bio_alloc(GFP_NOFS, 1);
+	if (unlikely(!bio)) {
+		__free_page(page);
+		return -ENOBUFS;
+	}
 
-	/* Don't let the VFS update atimes.  GFS2 handles this itself. */
-	sb->s_flags |= MS_NOATIME | MS_NODIRATIME;
+	bio->bi_sector = sector * (sb->s_blocksize >> 9);
+	bio->bi_bdev = sb->s_bdev;
+	bio_add_page(bio, page, PAGE_SIZE, 0);
+
+	bio->bi_end_io = end_bio_io_page;
+	bio->bi_private = page;
+	submit_bio(READ_SYNC | (1 << BIO_RW_META), bio);
+	wait_on_page_locked(page);
+	bio_put(bio);
+	if (!PageUptodate(page)) {
+		__free_page(page);
+		return -EIO;
+	}
+	p = kmap(page);
+	gfs2_sb_in(&sdp->sd_sb, p);
+	kunmap(page);
+	__free_page(page);
+	return 0;
+}
+/**
+ * gfs2_read_sb - Read super block
+ * @sdp: The GFS2 superblock
+ * @gl: the glock for the superblock (assumed to be held)
+ * @silent: Don't print message if mount fails
+ *
+ */
+
+static int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
+{
+	u32 hash_blocks, ind_blocks, leaf_blocks;
+	u32 tmp_blocks;
+	unsigned int x;
+	int error;
+
+	error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
+	if (error) {
+		if (!silent)
+			fs_err(sdp, "can't read superblock\n");
+		return error;
+	}
+
+	error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
+	if (error)
+		return error;
+
+	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
+			       GFS2_BASIC_BLOCK_SHIFT;
+	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
+	sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
+			  sizeof(struct gfs2_dinode)) / sizeof(u64);
+	sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
+			  sizeof(struct gfs2_meta_header)) / sizeof(u64);
+	sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
+	sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
+	sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
+	sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
+	sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
+				sizeof(struct gfs2_meta_header)) /
+			        sizeof(struct gfs2_quota_change);
+
+	/* Compute maximum reservation required to add a entry to a directory */
+
+	hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
+			     sdp->sd_jbsize);
+
+	ind_blocks = 0;
+	for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
+		tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
+		ind_blocks += tmp_blocks;
+	}
+
+	leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
+
+	sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
+
+	sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
+				sizeof(struct gfs2_dinode);
+	sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
+	for (x = 2;; x++) {
+		u64 space, d;
+		u32 m;
+
+		space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
+		d = space;
+		m = do_div(d, sdp->sd_inptrs);
+
+		if (d != sdp->sd_heightsize[x - 1] || m)
+			break;
+		sdp->sd_heightsize[x] = space;
+	}
+	sdp->sd_max_height = x;
+	sdp->sd_heightsize[x] = ~0;
+	gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
+
+	sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
+				 sizeof(struct gfs2_dinode);
+	sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
+	for (x = 2;; x++) {
+		u64 space, d;
+		u32 m;
+
+		space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
+		d = space;
+		m = do_div(d, sdp->sd_inptrs);
+
+		if (d != sdp->sd_jheightsize[x - 1] || m)
+			break;
+		sdp->sd_jheightsize[x] = space;
+	}
+	sdp->sd_max_jheight = x;
+	sdp->sd_jheightsize[x] = ~0;
+	gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
+
+	return 0;
 }
 
 static int init_names(struct gfs2_sbd *sdp, int silent)
@@ -224,51 +512,59 @@ fail:
 	return error;
 }
 
-static inline struct inode *gfs2_lookup_root(struct super_block *sb,
-					     u64 no_addr)
+static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
+			    u64 no_addr, const char *name)
 {
-	return gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
+	struct gfs2_sbd *sdp = sb->s_fs_info;
+	struct dentry *dentry;
+	struct inode *inode;
+
+	inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
+	if (IS_ERR(inode)) {
+		fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
+		return PTR_ERR(inode);
+	}
+	dentry = d_alloc_root(inode);
+	if (!dentry) {
+		fs_err(sdp, "can't alloc %s dentry\n", name);
+		iput(inode);
+		return -ENOMEM;
+	}
+	dentry->d_op = &gfs2_dops;
+	*dptr = dentry;
+	return 0;
 }
 
-static int init_sb(struct gfs2_sbd *sdp, int silent, int undo)
+static int init_sb(struct gfs2_sbd *sdp, int silent)
 {
 	struct super_block *sb = sdp->sd_vfs;
 	struct gfs2_holder sb_gh;
 	u64 no_addr;
-	struct inode *inode;
-	int error = 0;
+	int ret;
 
-	if (undo) {
-		if (sb->s_root) {
-			dput(sb->s_root);
-			sb->s_root = NULL;
-		}
-		return 0;
+	ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
+				LM_ST_SHARED, 0, &sb_gh);
+	if (ret) {
+		fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
+		return ret;
 	}
 
-	error = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
-				 LM_ST_SHARED, 0, &sb_gh);
-	if (error) {
-		fs_err(sdp, "can't acquire superblock glock: %d\n", error);
-		return error;
-	}
-
-	error = gfs2_read_sb(sdp, sb_gh.gh_gl, silent);
-	if (error) {
-		fs_err(sdp, "can't read superblock: %d\n", error);
+	ret = gfs2_read_sb(sdp, sb_gh.gh_gl, silent);
+	if (ret) {
+		fs_err(sdp, "can't read superblock: %d\n", ret);
 		goto out;
 	}
 
 	/* Set up the buffer cache and SB for real */
 	if (sdp->sd_sb.sb_bsize < bdev_hardsect_size(sb->s_bdev)) {
-		error = -EINVAL;
+		ret = -EINVAL;
 		fs_err(sdp, "FS block size (%u) is too small for device "
 		       "block size (%u)\n",
 		       sdp->sd_sb.sb_bsize, bdev_hardsect_size(sb->s_bdev));
 		goto out;
 	}
 	if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
-		error = -EINVAL;
+		ret = -EINVAL;
 		fs_err(sdp, "FS block size (%u) is too big for machine "
 		       "page size (%u)\n",
 		       sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
@@ -278,26 +574,21 @@ static int init_sb(struct gfs2_sbd *sdp, int silent, int undo)
 
 	/* Get the root inode */
 	no_addr = sdp->sd_sb.sb_root_dir.no_addr;
-	if (sb->s_type == &gfs2meta_fs_type)
-		no_addr = sdp->sd_sb.sb_master_dir.no_addr;
-	inode = gfs2_lookup_root(sb, no_addr);
-	if (IS_ERR(inode)) {
-		error = PTR_ERR(inode);
-		fs_err(sdp, "can't read in root inode: %d\n", error);
+	ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
+	if (ret)
 		goto out;
-	}
 
-	sb->s_root = d_alloc_root(inode);
-	if (!sb->s_root) {
-		fs_err(sdp, "can't get root dentry\n");
-		error = -ENOMEM;
-		iput(inode);
-	} else
-		sb->s_root->d_op = &gfs2_dops;
-	
+	/* Get the master inode */
+	no_addr = sdp->sd_sb.sb_master_dir.no_addr;
+	ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
+	if (ret) {
+		dput(sdp->sd_root_dir);
+		goto out;
+	}
+	sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
 out:
 	gfs2_glock_dq_uninit(&sb_gh);
-	return error;
+	return ret;
 }
 
 /**
@@ -372,6 +663,7 @@ static void gfs2_lm_others_may_mount(struct gfs2_sbd *sdp)
 
 static int init_journal(struct gfs2_sbd *sdp, int undo)
 {
+	struct inode *master = sdp->sd_master_dir->d_inode;
 	struct gfs2_holder ji_gh;
 	struct task_struct *p;
 	struct gfs2_inode *ip;
@@ -383,7 +675,7 @@ static int init_journal(struct gfs2_sbd *sdp, int undo)
 		goto fail_recoverd;
 	}
 
-	sdp->sd_jindex = gfs2_lookup_simple(sdp->sd_master_dir, "jindex");
+	sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
 	if (IS_ERR(sdp->sd_jindex)) {
 		fs_err(sdp, "can't lookup journal index: %d\n", error);
 		return PTR_ERR(sdp->sd_jindex);
@@ -506,25 +798,17 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo)
 {
 	int error = 0;
 	struct gfs2_inode *ip;
-	struct inode *inode;
+	struct inode *master = sdp->sd_master_dir->d_inode;
 
 	if (undo)
 		goto fail_qinode;
 
-	inode = gfs2_lookup_root(sdp->sd_vfs, sdp->sd_sb.sb_master_dir.no_addr);
-	if (IS_ERR(inode)) {
-		error = PTR_ERR(inode);
-		fs_err(sdp, "can't read in master directory: %d\n", error);
-		goto fail;
-	}
-	sdp->sd_master_dir = inode;
-
 	error = init_journal(sdp, undo);
 	if (error)
-		goto fail_master;
+		goto fail;
 
 	/* Read in the master inode number inode */
-	sdp->sd_inum_inode = gfs2_lookup_simple(sdp->sd_master_dir, "inum");
+	sdp->sd_inum_inode = gfs2_lookup_simple(master, "inum");
 	if (IS_ERR(sdp->sd_inum_inode)) {
 		error = PTR_ERR(sdp->sd_inum_inode);
 		fs_err(sdp, "can't read in inum inode: %d\n", error);
@@ -533,7 +817,7 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo)
 
 
 	/* Read in the master statfs inode */
-	sdp->sd_statfs_inode = gfs2_lookup_simple(sdp->sd_master_dir, "statfs");
+	sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
 	if (IS_ERR(sdp->sd_statfs_inode)) {
 		error = PTR_ERR(sdp->sd_statfs_inode);
 		fs_err(sdp, "can't read in statfs inode: %d\n", error);
@@ -541,7 +825,7 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo)
 	}
 
 	/* Read in the resource index inode */
-	sdp->sd_rindex = gfs2_lookup_simple(sdp->sd_master_dir, "rindex");
+	sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
 	if (IS_ERR(sdp->sd_rindex)) {
 		error = PTR_ERR(sdp->sd_rindex);
 		fs_err(sdp, "can't get resource index inode: %d\n", error);
@@ -552,7 +836,7 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo)
 	sdp->sd_rindex_uptodate = 0;
 
 	/* Read in the quota inode */
-	sdp->sd_quota_inode = gfs2_lookup_simple(sdp->sd_master_dir, "quota");
+	sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
 	if (IS_ERR(sdp->sd_quota_inode)) {
 		error = PTR_ERR(sdp->sd_quota_inode);
 		fs_err(sdp, "can't get quota file inode: %d\n", error);
@@ -571,8 +855,6 @@ fail_inum:
 	iput(sdp->sd_inum_inode);
 fail_journal:
 	init_journal(sdp, UNDO);
-fail_master:
-	iput(sdp->sd_master_dir);
 fail:
 	return error;
 }
@@ -583,6 +865,7 @@ static int init_per_node(struct gfs2_sbd *sdp, int undo)
 	char buf[30];
 	int error = 0;
 	struct gfs2_inode *ip;
+	struct inode *master = sdp->sd_master_dir->d_inode;
 
 	if (sdp->sd_args.ar_spectator)
 		return 0;
@@ -590,7 +873,7 @@ static int init_per_node(struct gfs2_sbd *sdp, int undo)
 	if (undo)
 		goto fail_qc_gh;
 
-	pn = gfs2_lookup_simple(sdp->sd_master_dir, "per_node");
+	pn = gfs2_lookup_simple(master, "per_node");
 	if (IS_ERR(pn)) {
 		error = PTR_ERR(pn);
 		fs_err(sdp, "can't find per_node directory: %d\n", error);
@@ -800,7 +1083,11 @@ static int fill_super(struct super_block *sb, void *data, int silent)
 		goto fail;
 	}
 
-	init_vfs(sb, SDF_NOATIME);
+	sb->s_magic = GFS2_MAGIC;
+	sb->s_op = &gfs2_super_ops;
+	sb->s_export_op = &gfs2_export_ops;
+	sb->s_time_gran = 1;
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
 
 	/* Set up the buffer cache and fill in some fake block size values
 	   to allow us to read-in the on-disk superblock. */
@@ -828,7 +1115,7 @@ static int fill_super(struct super_block *sb, void *data, int silent)
 	if (error)
 		goto fail_lm;
 
-	error = init_sb(sdp, silent, DO);
+	error = init_sb(sdp, silent);
 	if (error)
 		goto fail_locking;
 
@@ -869,7 +1156,11 @@ fail_per_node:
 fail_inodes:
 	init_inodes(sdp, UNDO);
 fail_sb:
-	init_sb(sdp, 0, UNDO);
+	if (sdp->sd_root_dir)
+		dput(sdp->sd_root_dir);
+	if (sdp->sd_master_dir)
+		dput(sdp->sd_master_dir);
+	sb->s_root = NULL;
 fail_locking:
 	init_locking(sdp, &mount_gh, UNDO);
 fail_lm:
@@ -887,151 +1178,63 @@ fail:
 }
 
 static int gfs2_get_sb(struct file_system_type *fs_type, int flags,
-		const char *dev_name, void *data, struct vfsmount *mnt)
+		       const char *dev_name, void *data, struct vfsmount *mnt)
 {
-	struct super_block *sb;
-	struct gfs2_sbd *sdp;
-	int error = get_sb_bdev(fs_type, flags, dev_name, data, fill_super, mnt);
-	if (error)
-		goto out;
-	sb = mnt->mnt_sb;
-	sdp = sb->s_fs_info;
-	sdp->sd_gfs2mnt = mnt;
-out:
-	return error;
+	return get_sb_bdev(fs_type, flags, dev_name, data, fill_super, mnt);
 }
 
-static int fill_super_meta(struct super_block *sb, struct super_block *new,
-			   void *data, int silent)
+static struct super_block *get_gfs2_sb(const char *dev_name)
 {
-	struct gfs2_sbd *sdp = sb->s_fs_info;
-	struct inode *inode;
-	int error = 0;
-
-	new->s_fs_info = sdp;
-	sdp->sd_vfs_meta = sb;
-
-	init_vfs(new, SDF_NOATIME);
-
-        /* Get the master inode */
-	inode = igrab(sdp->sd_master_dir);
-
-	new->s_root = d_alloc_root(inode);
-	if (!new->s_root) {
-		fs_err(sdp, "can't get root dentry\n");
-		error = -ENOMEM;
-		iput(inode);
-	} else
-		new->s_root->d_op = &gfs2_dops;
-
-	return error;
-}
-
-static int set_bdev_super(struct super_block *s, void *data)
-{
-	s->s_bdev = data;
-	s->s_dev = s->s_bdev->bd_dev;
-	return 0;
-}
-
-static int test_bdev_super(struct super_block *s, void *data)
-{
-	return s->s_bdev == data;
-}
-
-static struct super_block* get_gfs2_sb(const char *dev_name)
-{
-	struct kstat stat;
+	struct super_block *sb;
 	struct nameidata nd;
-	struct super_block *sb = NULL, *s;
 	int error;
 
 	error = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
 	if (error) {
-		printk(KERN_WARNING "GFS2: path_lookup on %s returned error\n",
-		       dev_name);
-		goto out;
-	}
-	error = vfs_getattr(nd.path.mnt, nd.path.dentry, &stat);
-
-	list_for_each_entry(s, &gfs2_fs_type.fs_supers, s_instances) {
-		if ((S_ISBLK(stat.mode) && s->s_dev == stat.rdev) ||
-		    (S_ISDIR(stat.mode) &&
-		     s == nd.path.dentry->d_inode->i_sb)) {
-			sb = s;
-			goto free_nd;
-		}
+		printk(KERN_WARNING "GFS2: path_lookup on %s returned error %d\n",
+		       dev_name, error);
+		return NULL;
 	}
-
-	printk(KERN_WARNING "GFS2: Unrecognized block device or "
-	       "mount point %s\n", dev_name);
-
-free_nd:
+	sb = nd.path.dentry->d_inode->i_sb;
+	if (sb && (sb->s_type == &gfs2_fs_type))
+		atomic_inc(&sb->s_active);
+	else
+		sb = NULL;
 	path_put(&nd.path);
-out:
 	return sb;
 }
 
 static int gfs2_get_sb_meta(struct file_system_type *fs_type, int flags,
 			    const char *dev_name, void *data, struct vfsmount *mnt)
 {
-	int error = 0;
-	struct super_block *sb = NULL, *new;
+	struct super_block *sb = NULL;
 	struct gfs2_sbd *sdp;
 
 	sb = get_gfs2_sb(dev_name);
 	if (!sb) {
 		printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n");
-		error = -ENOENT;
-		goto error;
+		return -ENOENT;
 	}
 	sdp = sb->s_fs_info;
-	if (sdp->sd_vfs_meta) {
-		printk(KERN_WARNING "GFS2: gfs2meta mount already exists\n");
-		error = -EBUSY;
-		goto error;
-	}
-	down(&sb->s_bdev->bd_mount_sem);
-	new = sget(fs_type, test_bdev_super, set_bdev_super, sb->s_bdev);
-	up(&sb->s_bdev->bd_mount_sem);
-	if (IS_ERR(new)) {
-		error = PTR_ERR(new);
-		goto error;
-	}
-	new->s_flags = flags;
-	strlcpy(new->s_id, sb->s_id, sizeof(new->s_id));
-	sb_set_blocksize(new, sb->s_blocksize);
-	error = fill_super_meta(sb, new, data, flags & MS_SILENT ? 1 : 0);
-	if (error) {
-		up_write(&new->s_umount);
-		deactivate_super(new);
-		goto error;
-	}
-
-	new->s_flags |= MS_ACTIVE;
-
-	/* Grab a reference to the gfs2 mount point */
-	atomic_inc(&sdp->sd_gfs2mnt->mnt_count);
-	return simple_set_mnt(mnt, new);
-error:
-	return error;
+	mnt->mnt_sb = sb;
+	mnt->mnt_root = dget(sdp->sd_master_dir);
+	return 0;
 }
 
 static void gfs2_kill_sb(struct super_block *sb)
 {
-	if (sb->s_fs_info) {
-		gfs2_delete_debugfs_file(sb->s_fs_info);
-		gfs2_meta_syncfs(sb->s_fs_info);
+	struct gfs2_sbd *sdp = sb->s_fs_info;
+	if (sdp) {
+		gfs2_meta_syncfs(sdp);
+		dput(sdp->sd_root_dir);
+		dput(sdp->sd_master_dir);
+		sdp->sd_root_dir = NULL;
+		sdp->sd_master_dir = NULL;
 	}
+	shrink_dcache_sb(sb);
 	kill_block_super(sb);
-}
-
-static void gfs2_kill_sb_meta(struct super_block *sb)
-{
-	struct gfs2_sbd *sdp = sb->s_fs_info;
-	generic_shutdown_super(sb);
-	sdp->sd_vfs_meta = NULL;
-	atomic_dec(&sdp->sd_gfs2mnt->mnt_count);
+	if (sdp)
+		gfs2_delete_debugfs_file(sdp);
 }
 
 struct file_system_type gfs2_fs_type = {
@@ -1046,7 +1249,6 @@ struct file_system_type gfs2meta_fs_type = {
 	.name = "gfs2meta",
 	.fs_flags = FS_REQUIRES_DEV,
 	.get_sb = gfs2_get_sb_meta,
-	.kill_sb = gfs2_kill_sb_meta,
 	.owner = THIS_MODULE,
 };