libglusterfs: Fix a crash due to race between inode_ctx_set and inode_ref

Issue:
Currently inode ref count is gaurded by inode_table->lock, and
inode_ctx is gauarded by inode->lock. With the new patch [1]
inode_ref was modified to change the inode_ctx to track the ref
count per xlator. Thus inode_ref performed under inode_table->lock
is modifying inode_ctx which has to be modified only under inode->lock

Solution:
When a inode is created, inode_ctx holder is allocated for all the xlators.
Hence in case of inode_ctx_set instead of using the first free index in
inode ctx holder, we can have predecided index for every xlator in the graph.

Credits Pranith K <pkarampu@redhat.com>

[1] http://review.gluster.org/13736

Change-Id: I1bfe111c211fcc4fcd761bba01dc87c4c69b5170
BUG: 1423373
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: https://review.gluster.org/16622
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/libglusterfs/src/graph.c b/libglusterfs/src/graph.c
index 47f473a580f..0c7d6cf6101 100644
--- a/libglusterfs/src/graph.c
+++ b/libglusterfs/src/graph.c
@@ -111,6 +111,7 @@ glusterfs_graph_set_first (glusterfs_graph_t *graph, xlator_t *xl)
         graph->first = xl;
 
         graph->xl_count++;
+        xl->xl_id = graph->xl_count;
 }