lease: Treat unlk request as noop if lease not found

When the glusterfs server recalls the lease, it expects
client to flush data and unlock the lease. If not it sets
a timer (starting from the time it sends RECALL request) and post
timeout, it revokes it.

Here we could have a race where in client did send UNLK
lease request but because of network delay it may have reached
after server revokes it. To handle such situations, treat
such requests as noop and return sucesss.

Change-Id: I166402d10273f4f115ff04030ecbc14676a01663
updates: bz#1648768
Signed-off-by: Soumya Koduri <skoduri@redhat.com>

1 files changed, 14 insertions, 2 deletions

diff --git a/xlators/features/leases/src/leases-internal.c b/xlators/features/leases/src/leases-internal.c
index 00fb670ff2a..2823ca5a262 100644
--- a/xlators/features/leases/src/leases-internal.c
+++ b/xlators/features/leases/src/leases-internal.c
@@ -624,17 +624,29 @@ __remove_lease(xlator_t *this, inode_t *inode, lease_inode_ctx_t *lease_ctx,
                  "lease type:%d, lease id:%s",
                  client_uid, lease->lease_type, leaseid_utoa(lease->lease_id));
 
+    /* There could be a race where in server recalled the lease and by the time
+     * client sends lease_unlock request, server may have revoked it. To handle
+     * such cases, if lease doesnt exist treat it as noop and return success.
+     */
     lease_entry = __get_lease_id_entry(lease_ctx, lease->lease_id);
-    if (!lease_entry || !(lease_entry->lease_type & lease->lease_type)) {
+    if (!lease_entry) {
         gf_msg(this->name, GF_LOG_INFO, 0, LEASE_MSG_INVAL_UNLK_LEASE,
                "Got unlock lease request from client:%s, but has no "
                "corresponding lock",
                client_uid);
+        ret = 0;
+        goto out;
+    }
+
+    if (!(lease_entry->lease_type & lease->lease_type)) {
+        gf_msg(this->name, GF_LOG_INFO, 0, LEASE_MSG_INVAL_UNLK_LEASE,
+               "Got unlock lease request from client:%s for an invalid "
+               "lease_type",
+               client_uid);
         ret = -EINVAL;
         errno = EINVAL;
         goto out;
     }
-
     lease_type = lease->lease_type;
     lease_entry->lease_type_cnt[lease_type]--;
     lease_entry->lease_cnt--;