afr:Don't wind reads for files in metadata split-brain

Problem: For a read on  a file in metadata split-brain:
1.lookup_done resets event_generation to zero.
2. readv is issued, goes to inode refresh due to mismatching event_gen.
3. After refresh is successful, we update event_generation, data and
metdata readable.
3. We then call afr_read_txn_refresh_done() which in turn calls
afr_inode_get_readable() but doesn't check for EIO. So afr_readv_wind
is called with local->readable (which is populated with data_readable),
thus winding the read to a brick.
4. Also, further parallel reads that come directly go to the wind path
because there is no inode_refresh needed.

Fix:
1.For any afr_read_txn(), readable must be an intersection of data and metadata
readable.
2.Check for EIO in afr_read_txn_refresh_done().

Change-Id: I22dd221fdfaf96d7aced2f474e28ed1337d69f0e
BUG: 1305031
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/13389
Reviewed-by: Ashish Pandey <aspandey@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

0 files changed, 0 insertions, 0 deletions