This patch replaces the single instance of kmirrord by one instance per mirror
set. This change is required to avoid a deadlock in kmirrord when the
persistent dirty log of a mirror itself resides on a mirror. The single
instance of kmirrord then issues a sync write to the dirty log in write_bits
which gets deferred to kmirrord itself later in the call chain. But kmirrord
never does the deferred work because it is still waiting for the sync
write_bits.
_mirror_sets is removed as it no longer needed, and we always flush the
workqueue before destroying it to ensure all work is complete before
destroying it.
Signed-off-by: Holger Smolinski <smolinski@de.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6ad36fe2b4