From 8638460540749ddb1beca9e9a68d655a6fe6df65 Mon Sep 17 00:00:00 2001 From: Abhijith Das Date: Fri, 25 Aug 2006 11:13:37 -0500 Subject: [GFS2] Allow mounting of gfs2 and gfs2meta at the same time This patch allows the simultaneous mounting of gfs2meta and gfs2 filesystems. A restriction however is that a gfs2meta fs may only be mounted if its corresponding gfs2 filesystem is also mounted. Also, a gfs2 filesystem cannot be unmounted before its gfs2meta filesystem. Signed-off-by: Abhijith Das Signed-off-by: Steven Whitehouse --- fs/gfs2/ops_fstype.c | 147 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 144 insertions(+), 3 deletions(-) (limited to 'fs/gfs2/ops_fstype.c') diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index c66067c84bc..e5a91ead250 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -15,6 +15,8 @@ #include #include #include +#include +#include #include #include "gfs2.h" @@ -813,7 +815,138 @@ static int fill_super(struct super_block *sb, void *data, int silent) static int gfs2_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { - return get_sb_bdev(fs_type, flags, dev_name, data, fill_super, 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 = (struct gfs2_sbd*)sb->s_fs_info; + sdp->sd_gfs2mnt = mnt; +out: + return error; +} + +static int fill_super_meta(struct super_block *sb, struct super_block *new, + void *data, int silent) +{ + 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); + } + 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 (void *)s->s_bdev == data; +} + +static struct super_block* get_gfs2_sb(const char *dev_name) +{ + struct kstat stat; + struct nameidata nd; + struct file_system_type *fstype; + struct super_block *sb = NULL, *s; + struct list_head *l; + 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.mnt, nd.dentry, &stat); + + fstype = get_fs_type("gfs2"); + list_for_each(l, &fstype->fs_supers) { + s = list_entry(l, struct super_block, s_instances); + if ((S_ISBLK(stat.mode) && s->s_dev == stat.rdev) || + (S_ISDIR(stat.mode) && s == nd.dentry->d_inode->i_sb)) { + sb = s; + goto free_nd; + } + } + + printk(KERN_WARNING "GFS2: Unrecognized block device or " + "mount point %s", dev_name); + +free_nd: + path_release(&nd); +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 gfs2_sbd *sdp; + char *gfs2mnt = NULL; + + sb = get_gfs2_sb(dev_name); + if (!sb) { + printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n"); + error = -ENOENT; + goto error; + } + sdp = (struct gfs2_sbd*) sb->s_fs_info; + if (sdp->sd_vfs_meta) { + printk(KERN_WARNING "GFS2: gfs2meta mount already exists\n"); + error = -EBUSY; + goto error; + } + mutex_lock(&sb->s_bdev->bd_mount_mutex); + new = sget(fs_type, test_bdev_super, set_bdev_super, sb->s_bdev); + mutex_unlock(&sb->s_bdev->bd_mount_mutex); + if (IS_ERR(new)) { + error = PTR_ERR(new); + goto error; + } + module_put(fs_type->owner); + 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: + if (gfs2mnt) + kfree(gfs2mnt); + return error; } static void gfs2_kill_sb(struct super_block *sb) @@ -821,6 +954,14 @@ static void gfs2_kill_sb(struct super_block *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); +} + struct file_system_type gfs2_fs_type = { .name = "gfs2", .fs_flags = FS_REQUIRES_DEV, @@ -832,8 +973,8 @@ struct file_system_type gfs2_fs_type = { struct file_system_type gfs2meta_fs_type = { .name = "gfs2meta", .fs_flags = FS_REQUIRES_DEV, - .get_sb = gfs2_get_sb, - .kill_sb = gfs2_kill_sb, + .get_sb = gfs2_get_sb_meta, + .kill_sb = gfs2_kill_sb_meta, .owner = THIS_MODULE, }; -- cgit v1.2.3