cluster/dht: fix race between two directory renames

let the race get arbitrated at the dst_hashed subvolume.

Signed-off-by: Anand Avati <avati@gluster.com>

BUG: 2522 ([glusterfs-3.1.3qa8]: rm -rf shows invalid argument)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2522

1 files changed, 79 insertions, 7 deletions

diff --git a/xlators/cluster/dht/src/dht-rename.c b/xlators/cluster/dht/src/dht-rename.c
index 2db707cb57b..dd1354269bb 100644
--- a/xlators/cluster/dht/src/dht-rename.c
+++ b/xlators/cluster/dht/src/dht-rename.c
@@ -90,30 +90,102 @@ unwind:
 }
 
 
-
 int
-dht_rename_dir_do (call_frame_t *frame, xlator_t *this)
+dht_rename_hashed_dir_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                           int32_t op_ret, int32_t op_errno, struct iatt *stbuf,
+                           struct iatt *preoldparent,
+                           struct iatt *postoldparent,
+                           struct iatt *prenewparent,
+                           struct iatt *postnewparent)
 {
-        dht_local_t  *local = NULL;
         dht_conf_t   *conf = NULL;
+        dht_local_t  *local = NULL;
+        int           call_cnt = 0;
+        call_frame_t *prev = NULL;
         int           i = 0;
 
         conf = this->private;
         local = frame->local;
+        prev = cookie;
 
-        if (local->op_ret == -1)
-                goto err;
+        if (op_ret == -1) {
+                /* TODO: undo the damage */
 
-        local->call_cnt = conf->subvolume_cnt;
-        local->op_ret = 0;
+                gf_log (this->name, GF_LOG_INFO,
+                        "rename %s -> %s on %s failed (%s)",
+                        local->loc.path, local->loc2.path,
+                        prev->this->name, strerror (op_errno));
+
+                local->op_ret   = op_ret;
+                local->op_errno = op_errno;
+                goto unwind;
+        }
+        /* TODO: construct proper stbuf for dir */
+        /*
+         * FIXME: is this the correct way to build stbuf and
+         * parent bufs?
+         */
+        dht_iatt_merge (this, &local->stbuf, stbuf, prev->this);
+        dht_iatt_merge (this, &local->preoldparent, preoldparent,
+                        prev->this);
+        dht_iatt_merge (this, &local->postoldparent, postoldparent,
+                        prev->this);
+        dht_iatt_merge (this, &local->preparent, prenewparent,
+                        prev->this);
+        dht_iatt_merge (this, &local->postparent, postnewparent,
+                        prev->this);
+
+        call_cnt = local->call_cnt = conf->subvolume_cnt - 1;
+
+        if (!local->call_cnt)
+                goto unwind;
 
         for (i = 0; i < conf->subvolume_cnt; i++) {
+                if (conf->subvolumes[i] == local->dst_hashed)
+                        continue;
                 STACK_WIND (frame, dht_rename_dir_cbk,
                             conf->subvolumes[i],
                             conf->subvolumes[i]->fops->rename,
                             &local->loc, &local->loc2);
+                if (!--call_cnt)
+                        break;
         }
 
+
+        return 0;
+unwind:
+        WIPE (&local->preoldparent);
+        WIPE (&local->postoldparent);
+        WIPE (&local->preparent);
+        WIPE (&local->postparent);
+
+        DHT_STACK_UNWIND (rename, frame, local->op_ret, local->op_errno,
+                          &local->stbuf, &local->preoldparent,
+                          &local->postoldparent,
+                          &local->preparent, &local->postparent);
+
+        return 0;
+}
+
+
+int
+dht_rename_dir_do (call_frame_t *frame, xlator_t *this)
+{
+        dht_local_t  *local = NULL;
+        dht_conf_t   *conf = NULL;
+
+        conf = this->private;
+        local = frame->local;
+
+        if (local->op_ret == -1)
+                goto err;
+
+        local->op_ret = 0;
+
+        STACK_WIND (frame, dht_rename_hashed_dir_cbk,
+                    local->dst_hashed,
+                    local->dst_hashed->fops->rename,
+                    &local->loc, &local->loc2);
         return 0;
 
 err: