performance/io-threads: Exit threads in fini() as well

Problem:
io-threads starts the thread in 'init()' but doesn't clean them up
on 'fini()'. It relies on PARENT_DOWN to exit threads but there can
be cases where event before PARENT_UP the graph init code can think
of issuing fini(). This code path is hit when glfs_init() is called
on a volume that is in 'stopped' state. It leads to a crash in ganesha
process, because the io-thread tries to access freed memory.

Fix:
Ideal fix would be to wait for all fops in io-thread list to be completed on
PARENT_DOWN, and have fini() do cleanup of threads. Because there is no proper
documentation about how PARENT_DOWN/fini are supposed to be used,
we are getting different kinds of sequences in different higher level protocols.
So for now cleaning up in both PARENT_DOWN and fini(). Fuse doesn't call fini()
gfapi is not calling PARENT_DOWN in some cases, so for now I don't see
another way out.

 >BUG: 1396793
 >Change-Id: I9c9154e7d57198dbaff0f30d3ffc25f6d8088aec
 >Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
 >Reviewed-on: http://review.gluster.org/15888
 >Smoke: Gluster Build System <jenkins@build.gluster.org>
 >CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
 >NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
 >Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
 >(cherry picked from commit 25817a8c868b6c1b8149117f13e4216a99e453aa)

Change-Id: Id55e7c2f3e90c013d40e59bfbfb3f1583b8c4061
BUG: 1397381
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/15921
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>

0 files changed, 0 insertions, 0 deletions