ceph: renew caps for read/write if mds session got killed.

When mds session gets killed, read/write operation may hang.
Client waits for Frw caps, but mds does not know what caps client
wants. To recover this, client sends an open request to mds. The
request will tell mds what caps client wants.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index cff85af425d4..1e5965d17cb1 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1133,6 +1133,8 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
                 struct ceph_mds_client *mdsc =
                         ceph_sb_to_client(inode->i_sb)->mdsc;
 
+                ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
+
                 while (true) {
                         struct rb_node *n = rb_first(&ci->i_cap_flush_tree);
                         if (!n)
@@ -1181,7 +1183,9 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
                 list_del(&cf->list);
                 ceph_free_cap_flush(cf);
         }
-        while (drop--)
+
+        wake_up_all(&ci->i_cap_wq);
+        if (drop)
                 iput(inode);
         return 0;
 }