ceph: don't take s_mutex in try_flush_caps

The s_mutex doesn't protect anything in this codepath.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 95f56b3..6fae3cb 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2146,26 +2146,17 @@ static int try_flush_caps(struct inode *inode, u64 *ptid)
 {
        struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
        struct ceph_inode_info *ci = ceph_inode(inode);
-       struct ceph_mds_session *session = NULL;
        int flushing = 0;
        u64 flush_tid = 0, oldest_flush_tid = 0;
 
-retry:
        spin_lock(&ci->i_ceph_lock);
 retry_locked:
        if (ci->i_dirty_caps && ci->i_auth_cap) {
                struct ceph_cap *cap = ci->i_auth_cap;
                struct cap_msg_args arg;
+               struct ceph_mds_session *session = cap->session;
 
-               if (session != cap->session) {
-                       spin_unlock(&ci->i_ceph_lock);
-                       if (session)
-                               mutex_unlock(&session->s_mutex);
-                       session = cap->session;
-                       mutex_lock(&session->s_mutex);
-                       goto retry;
-               }
-               if (cap->session->s_state < CEPH_MDS_SESSION_OPEN) {
+               if (session->s_state < CEPH_MDS_SESSION_OPEN) {
                        spin_unlock(&ci->i_ceph_lock);
                        goto out;
                }
@@ -2202,9 +2193,6 @@ retry_locked:
                spin_unlock(&ci->i_ceph_lock);
        }
 out:
-       if (session)
-               mutex_unlock(&session->s_mutex);
-
        *ptid = flush_tid;
        return flushing;
 }