core: glusterfsd keeping fd open in index xlator

Problem: At the time of processing GF_EVENT_PARENT_DOWN
         at brick xlator, it forwards the event to next xlator
         only while xlator ensures no stub is in progress.
         At io-thread xlator it decreases stub_cnt before the process
         a stub and notify EVENT to next xlator

Solution: Introduce a new counter to save stub_cnt and decrease
          the counter after process the stub completely at io-thread
          xlator.
          To avoid brick crash at the time of call xlator_mem_cleanup
          move only brick xlator if detach brick name has found in
          the graph

Note: Thanks to pranith for sharing a simple reproducer to
      reproduce the same

fixes bz#1637934
Change-Id: I1a694a001f7a5417e8771e3adf92c518969b6baa
Signed-off-by: Mohit Agrawal <moagrawal@redhat.com>

1 files changed, 1 insertions, 13 deletions

diff --git a/libglusterfs/src/xlator.c b/libglusterfs/src/xlator.c
index 01cb27896ee..b305ad50e5d 100644
--- a/libglusterfs/src/xlator.c
+++ b/libglusterfs/src/xlator.c
@@ -1051,6 +1051,7 @@ xlator_mem_cleanup(xlator_t *this)
         top = ctx->active->first;
         LOCK(&ctx->volfile_lock);
         /* TODO here we have leak for xlator node in a graph */
+        /* Need to move only top xlator from a graph */
         for (trav_p = &top->children; *trav_p; trav_p = &(*trav_p)->next) {
             victim = (*trav_p)->xlator;
             if (victim->call_cleanup && !strcmp(victim->name, this->name)) {
@@ -1058,19 +1059,6 @@ xlator_mem_cleanup(xlator_t *this)
                 break;
             }
         }
-        /* TODO Sometime brick xlator is not moved from graph so followed below
-           approach to move brick xlator from a graph, will move specific brick
-           xlator from graph only while inode table and mem_acct are cleaned up
-        */
-        trav_p = &top->children;
-        while (*trav_p) {
-            victim = (*trav_p)->xlator;
-            if (victim->call_cleanup && !victim->itable && !victim->mem_acct) {
-                (*trav_p) = (*trav_p)->next;
-            } else {
-                trav_p = &(*trav_p)->next;
-            }
-        }
         UNLOCK(&ctx->volfile_lock);
     }
 }