afr: use data trylock mode in read/write self-heal trigger paths

Self-heal data lock contention between clients and glustershd
instances can lead to long wait and user response times if the
client ends up pending its lock on glustershd self-heal of a large
file. We have reports of guest vm instances going completely
unresponsive during self-heal of virtual disk images.

Optimize the read/write self-heal trigger codepath
(i.e., afr_open_fd_fix()) to trylock for self-heal and skip the
self-heal otherwise to minimize the likelihood of a running/active
guest of competing with glustershd on arrival of a brick. Note that
lock contention is still possible from the client (e.g., via
lookup).

BUG: 874045
Change-Id: I077e2c0aaa424b80734a471284173bda8871cdc3
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/1911
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Vijay Bellur <vbellur@redhat.com>

0 files changed, 0 insertions, 0 deletions