dht:remember locked subvol and send unlock to the same

During locking we send lock request to cached subvol,
and normally we unlock to the cached subvol
But with parallel fresh lookup on a directory, there
is a race window where the cached subvol can change
and the unlock can go into a different subvol from
which we took lock.

This will result in a stale lock held on one of the
subvol.

So we will store the details of subvol which we took the lock
and will unlock from the same subvol

Change-Id: I47df99491671b10624eb37d1d17e40bacf0b15eb
BUG: 1311002
Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
Reviewed-on: http://review.gluster.org/13492
Reviewed-by: N Balachandran <nbalacha@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/xlators/cluster/dht/src/dht-common.h b/xlators/cluster/dht/src/dht-common.h
index b2e9df68996..9a71c46c8e4 100644
--- a/xlators/cluster/dht/src/dht-common.h
+++ b/xlators/cluster/dht/src/dht-common.h
@@ -101,6 +101,7 @@ typedef struct dht_stat_time dht_stat_time_t;
 struct dht_inode_ctx {
         dht_layout_t    *layout;
         dht_stat_time_t  time;
+        xlator_t        *lock_subvol;
 };
 
 typedef struct dht_inode_ctx dht_inode_ctx_t;
@@ -285,6 +286,8 @@ struct dht_local {
                 int                 op_errno;
         } lock;
 
+        short           lock_type;
+
         call_stub_t *stub;
         int32_t      parent_disk_layout[4];
 };
@@ -1218,4 +1221,12 @@ dht_release (xlator_t *this, fd_t *fd);
 
 int32_t
 dht_set_fixed_dir_stat (struct iatt *stat);
+
+xlator_t*
+dht_get_lock_subvolume (xlator_t *this, struct gf_flock *lock,
+                        dht_local_t *local);
+
+int
+dht_lk_inode_unref (call_frame_t *frame, int32_t op_ret);
+
 #endif/* _DHT_H */