From b6a0780d86e7c6afe7ae0d9a87e6fe5c62b4d792 Mon Sep 17 00:00:00 2001 From: Pranith Kumar K Date: Thu, 31 Mar 2016 14:40:09 +0530 Subject: cluster/afr: Fix spurious entries in heal info Problem: Locking schemes in afr-v1 were locking the directory/file completely during self-heal. Newer schemes of locking don't require Full directory, file locking. But afr-v2 still has compatibility code to work-well with older clients, where in entry-self-heal it takes a lock on a special 256 character name which can't be created on the fs. Similarly for data self-heal there used to be a lock on (LLONG_MAX-2, 1). Old locking scheme requires heal info to take sh-domain locks before examining heal-state. If it doesn't take sh-domain locks, then there is a possibility of heal-info hanging till self-heal completes because of compatibility locks. But the problem with heal-info taking sh-domain locks is that if two heal-info or shd, heal-info try to inspect heal state in parallel using trylocks on sh-domain, there is a possibility that both of them assuming a heal is in progress. This was leading to spurious entries being shown in heal-info. Fix: As long as there is afr-v1 way of locking, we can't fix this problem with simple solutions. If we know that the cluster is running newer versions of locking schemes, in those cases we can give accurate information in heal-info. So introduce a new option called 'locking-scheme' which if it is 'granular' will give correct information in heal-info. Not only that, Extra network hops for taking compatibility locks, sh-domain locks in heal info will not be necessary anymore. Thus it improves performance. BUG: 1322850 Change-Id: Ia563c5f096b5922009ff0ec1c42d969d55d827a3 Signed-off-by: Pranith Kumar K Reviewed-on: http://review.gluster.org/13873 Smoke: Gluster Build System NetBSD-regression: NetBSD Build System CentOS-regression: Gluster Build System Reviewed-by: Ashish Pandey Reviewed-by: Anuradha Talur Reviewed-by: Krutika Dhananjay --- xlators/cluster/afr/src/afr-self-heal-entry.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'xlators/cluster/afr/src/afr-self-heal-entry.c') diff --git a/xlators/cluster/afr/src/afr-self-heal-entry.c b/xlators/cluster/afr/src/afr-self-heal-entry.c index c8e2c98db0e..fccffa7dbac 100644 --- a/xlators/cluster/afr/src/afr-self-heal-entry.c +++ b/xlators/cluster/afr/src/afr-self-heal-entry.c @@ -744,8 +744,11 @@ afr_selfheal_entry (call_frame_t *frame, xlator_t *this, inode_t *inode) unsigned char *long_name_locked = NULL; fd_t *fd = NULL; int ret = 0; + gf_boolean_t granular_locks = _gf_false; priv = this->private; + if (strcmp ("granular", priv->locking_scheme) == 0) + granular_locks = _gf_true; fd = afr_selfheal_data_opendir (this, inode); if (!fd) @@ -772,10 +775,13 @@ afr_selfheal_entry (call_frame_t *frame, xlator_t *this, inode_t *inode) goto unlock; } - ret = afr_selfheal_tryentrylk (frame, this, inode, this->name, - LONG_FILENAME, long_name_locked); + if (!granular_locks) { + ret = afr_selfheal_tryentrylk (frame, this, inode, + this->name, LONG_FILENAME, + long_name_locked); + } { - if (ret < 1) { + if (!granular_locks && ret < 1) { gf_msg_debug (this->name, 0, "%s: Skipping" " entry self-heal as only %d " "sub-volumes could be " @@ -788,8 +794,9 @@ afr_selfheal_entry (call_frame_t *frame, xlator_t *this, inode_t *inode) } ret = __afr_selfheal_entry (frame, this, fd, locked_on); } - afr_selfheal_unentrylk (frame, this, inode, this->name, - LONG_FILENAME, long_name_locked); + if (!granular_locks) + afr_selfheal_unentrylk (frame, this, inode, this->name, + LONG_FILENAME, long_name_locked); } unlock: afr_selfheal_unentrylk (frame, this, inode, priv->sh_domain, NULL, locked_on); -- cgit