gfapi: glfs_subvol_done should NOT wait for graph migration.

In graph_setup function glfs_subvol_done is called which
is executed in an epoll thread. glfs_lock waits on other
thread to finish graph migration. This can lead to dead lock
if we consume all the epoll threads.

In general any call-back function executed in epoll thread
should not call any blocking call which waits on a network
reply either directly or indirectly, e.g. syncop functions
should not be called in these threads.

As a fix we should not wait for migration in the call-back path.

> Reviewed-on: http://review.gluster.org/15913
> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
> Smoke: Gluster Build System <jenkins@build.gluster.org>
> Reviewed-by: Niels de Vos <ndevos@redhat.com>
> CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
(cherry picked from commit 17d10b42fc4041442e6cd0bfda45944edea498c6)

Change-Id: If96d0689fe1b4d74631e383048cdc30b01690dc2
BUG: 1399915
Signed-off-by: Rajesh Joseph <rjoseph@redhat.com>
Reviewed-on: http://review.gluster.org/15977
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: Shyamsundar Ranganathan <srangana@redhat.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>

0 files changed, 0 insertions, 0 deletions