From b7ca9c9273e5eebd63880dd8a6e4e5c18fc7901d Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Fri, 21 Dec 2012 20:23:31 +0000 Subject: [PATCH] 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 Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon --- Reading git-format-patch failed