From e4ea25e9eea0f7259c11333f7a75049f3dccb7a7 Mon Sep 17 00:00:00 2001 From: Ravishankar N Date: Fri, 5 Feb 2016 15:10:06 +0530 Subject: afr:Don't wind reads for files in metadata split-brain Backport of http://review.gluster.org/#/c/13389/ 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: 1349881 Signed-off-by: Ravishankar N (cherry picked from commit 7a1c1e2904701496968ed14b6d7479fb706c3188) Reviewed-on: http://review.gluster.org/14791 NetBSD-regression: NetBSD Build System CentOS-regression: Gluster Build System Tested-by: Gluster Build System Smoke: Gluster Build System Reviewed-by: Pranith Kumar Karampuri --- xlators/cluster/afr/src/afr-read-txn.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) (limited to 'xlators') diff --git a/xlators/cluster/afr/src/afr-read-txn.c b/xlators/cluster/afr/src/afr-read-txn.c index 32ad6a46d17..74749f029c8 100644 --- a/xlators/cluster/afr/src/afr-read-txn.c +++ b/xlators/cluster/afr/src/afr-read-txn.c @@ -83,7 +83,7 @@ afr_read_txn_refresh_done (call_frame_t *frame, xlator_t *this, int err) &event_generation, local->transaction.type); - if (ret == -1 || !event_generation) + if (ret == -EIO || !event_generation) /* Even after refresh, we don't have a good read subvolume. Time to bail */ AFR_READ_TXN_SET_ERROR_AND_GOTO (-1, EIO, -1, readfn); @@ -218,18 +218,12 @@ afr_read_txn (call_frame_t *frame, xlator_t *this, inode_t *inode, } local->transaction.type = type; - if (local->op == GF_FOP_FSTAT || local->op == GF_FOP_STAT) { - ret = afr_inode_read_subvol_get (inode, this, data, metadata, - &event_generation); - AFR_INTERSECT (local->readable, data, metadata, - priv->child_count); - } else { - ret = afr_inode_read_subvol_type_get (inode, this, local->readable, - &event_generation, type); - } + ret = afr_inode_read_subvol_get (inode, this, data, metadata, + &event_generation); if (ret == -1) /* very first transaction on this inode */ goto refresh; + AFR_INTERSECT (local->readable, data, metadata, priv->child_count); gf_msg_debug (this->name, 0, "%s: generation now vs cached: %d, " "%d", uuid_utoa (inode->gfid), local->event_generation, -- cgit