afr: don't update readables if inode refresh failed on all children

Problem:
If inode refresh failed on all children of afr due to ENOENT (say file
migrated by dht), it resets the readables to zero. Any inflight txn which
then later comes on the inode fails with EIO because no readable
children present for the inode.

Fix:
Don't update readables when inode refresh fails on *all* children of
afr. In that way any inflight txns will either proceed with its own inode
refresh if needed and fail it with the right errno or use the old value
of readables and continue with the txn.

Also, add quorum checks to the beginning of afr_transaction(). Otherwise, we
seem to be winding the lock and checking for quorum only in pre-op pahse.

Note: This should ideally fix BZ 1329505 since the stop gap fix for
it is has been reverted at https://review.gluster.org/#/c/20028.

Change-Id: Ia638c092d8d12dc27afb3cdad133394845061319
updates: bz#1584483
Signed-off-by: Ravishankar N <ravishankar@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c
index 9c0963781e3..bfea096cf3b 100644
--- a/xlators/cluster/afr/src/afr-transaction.c
+++ b/xlators/cluster/afr/src/afr-transaction.c
@@ -2452,7 +2452,7 @@ afr_write_txn_refresh_done (call_frame_t *frame, xlator_t *this, int err)
         afr_local_t   *local           = frame->local;
 
         if (err) {
-                AFR_SET_ERROR_AND_CHECK_SPLIT_BRAIN(-1, -err);
+                AFR_SET_ERROR_AND_CHECK_SPLIT_BRAIN(-1, err);
                 goto fail;
         }
 
@@ -2478,6 +2478,11 @@ afr_transaction (call_frame_t *frame, xlator_t *this, afr_transaction_type type)
 
         local->transaction.type   = type;
 
+        if (priv->quorum_count && !afr_has_quorum (local->child_up, this)) {
+                ret = -afr_quorum_errno(priv);
+                goto out;
+        }
+
         if (!afr_is_consistent_io_possible (local, priv, &ret)) {
                 ret = -ret; /*op_errno to ret conversion*/
                 goto out;