ocfs2: do not lock/unlock() inode DLM lock

DLM does not cache locks.  So, blocking lock and unlock will only make
the performance worse where contention over the locks is high.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 20276e340339b64d4ca9c2533e97430801d287a4..f92612e4b9d61144b13021c83dd8b4b1e9553ac5 100644 (file)
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -2432,12 +2432,6 @@ bail:
  * done this we have to return AOP_TRUNCATED_PAGE so the aop method
  * that called us can bubble that back up into the VFS who will then
  * immediately retry the aop call.
- *
- * We do a blocking lock and immediate unlock before returning, though, so that
- * the lock has a great chance of being cached on this node by the time the VFS
- * calls back to retry the aop.    This has a potential to livelock as nodes
- * ping locks back and forth, but that's a risk we're willing to take to avoid
- * the lock inversion simply.
  */
 int ocfs2_inode_lock_with_page(struct inode *inode,
                              struct buffer_head **ret_bh,
@@ -2449,8 +2443,6 @@ int ocfs2_inode_lock_with_page(struct inode *inode,
        ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
        if (ret == -EAGAIN) {
                unlock_page(page);
-               if (ocfs2_inode_lock(inode, ret_bh, ex) == 0)
-                       ocfs2_inode_unlock(inode, ex);
                ret = AOP_TRUNCATED_PAGE;
        }