[GFS2] Fix recursive locking in gfs2_getattr
The readdirplus NFS operation can result in gfs2_getattr being
called with the glock already held. In this case we do not want
to try and grab the lock again.
This fixes Red Hat bugzilla #215727
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index fd9fee2..fbe38c1 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -992,6 +992,12 @@
* @dentry: The dentry to stat
* @stat: The inode's stats
*
+ * This may be called from the VFS directly, or from within GFS2 with the
+ * inode locked, so we look to see if the glock is already locked and only
+ * lock the glock if its not already been done. Note that its the NFS
+ * readdirplus operation which causes this to be called (from filldir)
+ * with the glock already held.
+ *
* Returns: errno
*/
@@ -1002,14 +1008,20 @@
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
int error;
+ int unlock = 0;
- error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
- if (!error) {
- generic_fillattr(inode, stat);
- gfs2_glock_dq_uninit(&gh);
+ if (gfs2_glock_is_locked_by_me(ip->i_gl) == 0) {
+ error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
+ if (error)
+ return error;
+ unlock = 1;
}
- return error;
+ generic_fillattr(inode, stat);
+ if (unlock);
+ gfs2_glock_dq_uninit(&gh);
+
+ return 0;
}
static int gfs2_setxattr(struct dentry *dentry, const char *name,