]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
dm thin: replace dm_cell_release_singleton with cell_defer_except
authorJoe Thornber <ejt@redhat.com>
Fri, 21 Dec 2012 20:23:31 +0000 (20:23 +0000)
committerAlasdair G Kergon <agk@redhat.com>
Fri, 21 Dec 2012 20:23:31 +0000 (20:23 +0000)
commitb7ca9c9273e5eebd63880dd8a6e4e5c18fc7901d
tree8022d8d5f6f03d80896407562b48c554a8cbfa6f
parentc1a94672a830e01d58c7c7e8de530c3f136d6ff2
dm thin: replace dm_cell_release_singleton with cell_defer_except

Change existing users of the function dm_cell_release_singleton to share
cell_defer_except instead, and then remove the now-unused function.

Everywhere that calls dm_cell_release_singleton, the bio in question
is the holder of the cell.

If there are no non-holder entries in the cell then cell_defer_except
behaves exactly like dm_cell_release_singleton.  Conversely, if there
*are* non-holder entries then dm_cell_release_singleton must not be used
because those entries would need to be deferred.

Consequently, it is safe to replace use of dm_cell_release_singleton
with cell_defer_except.

This patch is a pre-requisite for "dm thin: fix race between
simultaneous io and discards to same block".

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm-bio-prison.c
drivers/md/dm-bio-prison.h
drivers/md/dm-thin.c