From f6d03139d745198b434f65a28aabed524f415a4c Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Fri, 5 Jun 2009 07:18:57 +0100 Subject: GFS2: Fix locking issue mounting gfs2meta fs This patch uses sget() to get a reference to the existing gfs2 sb when mouting the gfs2meta filesystem (in fact thats just another mount of the gfs2 filesystem with a different root and this interface is for backward compatibility). Signed-off-by: Steven Whitehouse Reported-by: Benjamin Marzinski Tested-by: Benjamin Marzinski Cc: Christoph Hellwig --- fs/gfs2/ops_fstype.c | 36 ++++++++++++++++++++++-------------- 1 file changed, 22 insertions(+), 14 deletions(-) (limited to 'fs/gfs2') diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index 2cd1164c88d..9da161cbb30 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -1273,9 +1273,20 @@ static int gfs2_get_sb(struct file_system_type *fs_type, int flags, return get_sb_bdev(fs_type, flags, dev_name, data, fill_super, mnt); } +static int test_meta_super(struct super_block *s, void *ptr) +{ + struct block_device *bdev = ptr; + return (bdev == s->s_bdev); +} + +static int set_meta_super(struct super_block *s, void *ptr) +{ + return -EINVAL; +} + static struct super_block *get_gfs2_sb(const char *dev_name) { - struct super_block *sb; + struct super_block *s; struct path path; int error; @@ -1283,30 +1294,27 @@ static struct super_block *get_gfs2_sb(const char *dev_name) if (error) { printk(KERN_WARNING "GFS2: path_lookup on %s returned error %d\n", dev_name, error); - return NULL; + return ERR_PTR(-ENOENT); } - sb = path.dentry->d_inode->i_sb; - if (sb && (sb->s_type == &gfs2_fs_type)) - atomic_inc(&sb->s_active); - else - sb = NULL; + s = sget(&gfs2_fs_type, test_meta_super, set_meta_super, + path.dentry->d_inode->i_sb->s_bdev); path_put(&path); - return sb; + return s; } static int gfs2_get_sb_meta(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { - struct super_block *sb = NULL; + struct super_block *s; struct gfs2_sbd *sdp; - sb = get_gfs2_sb(dev_name); - if (!sb) { + s = get_gfs2_sb(dev_name); + if (IS_ERR(s)) { printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n"); - return -ENOENT; + return PTR_ERR(s); } - sdp = sb->s_fs_info; - mnt->mnt_sb = sb; + sdp = s->s_fs_info; + mnt->mnt_sb = s; mnt->mnt_root = dget(sdp->sd_master_dir); return 0; } -- cgit v1.2.3