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 <swhiteho@redhat.com>
Reported-by: Benjamin Marzinski <bmarzins@redhat.com>
Tested-by: Benjamin Marzinski <bmarzins@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
This commit is contained in:
Steven Whitehouse 2009-06-05 07:18:57 +01:00
parent e09f9446b9
commit f6d03139d7

View file

@ -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;
}