features/quota: Fix race-condition while resuming stub.

- call-stub is resumed in fops calling quota_check_limit and quota_check_limit
    when validate_count is zero, indicating no pending validates. During
    validates, validate_count was decremented in quota_validate_cbk, but check
    for validate_count being zero was done in quota_check_limit (which is
    called by quota_validate_cbk). Hence there is a time window b/w decrementing
    validate_count in quota_validate_cbk and checking whether
    validate_count is zero in quota_check_limit, during which if the
    control is passed to code in fop checking for validate_count being zero,
    same stub will be resumed twice - once in fop and once in quota_check_limit.

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

BUG: 2686 ([glusterfs-3.2.0qa8]: nfs server crashed)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2686

1 files changed, 1 insertions, 1 deletions

diff --git a/xlators/features/quota/src/quota.h b/xlators/features/quota/src/quota.h
index d53894ab48f..fce2e54bd60 100644
--- a/xlators/features/quota/src/quota.h
+++ b/xlators/features/quota/src/quota.h
@@ -134,7 +134,6 @@ struct quota_inode_ctx {
         int64_t          size;
         int64_t          limit;
         struct iatt      buf;
-        char             just_validated;
         struct list_head parents;
         struct timeval   tv;
         gf_lock_t        lock;
@@ -154,6 +153,7 @@ struct quota_local {
         int32_t      op_errno;
         int64_t      size;
         int64_t      limit;
+        char         just_validated;
         inode_t     *inode;
         call_stub_t *stub;
 };