summaryrefslogtreecommitdiffstats
path: root/drivers/md/dm-bio-prison.c
diff options
context:
space:
mode:
authorJoe Thornber <ejt@redhat.com>2012-12-21 20:23:31 +0000
committerAlasdair G Kergon <agk@redhat.com>2012-12-21 20:23:31 +0000
commitb7ca9c9273e5eebd63880dd8a6e4e5c18fc7901d (patch)
tree8022d8d5f6f03d80896407562b48c554a8cbfa6f /drivers/md/dm-bio-prison.c
parentc1a94672a830e01d58c7c7e8de530c3f136d6ff2 (diff)
downloadlinux-b7ca9c9273e5eebd63880dd8a6e4e5c18fc7901d.tar.gz
linux-b7ca9c9273e5eebd63880dd8a6e4e5c18fc7901d.tar.bz2
linux-b7ca9c9273e5eebd63880dd8a6e4e5c18fc7901d.zip
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>
Diffstat (limited to 'drivers/md/dm-bio-prison.c')
-rw-r--r--drivers/md/dm-bio-prison.c25
1 files changed, 0 insertions, 25 deletions
diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c
index e4e841567459..aefb78e3cbf9 100644
--- a/drivers/md/dm-bio-prison.c
+++ b/drivers/md/dm-bio-prison.c
@@ -208,31 +208,6 @@ void dm_cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios)
EXPORT_SYMBOL_GPL(dm_cell_release);
/*
- * There are a couple of places where we put a bio into a cell briefly
- * before taking it out again. In these situations we know that no other
- * bio may be in the cell. This function releases the cell, and also does
- * a sanity check.
- */
-static void __cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
-{
- BUG_ON(cell->holder != bio);
- BUG_ON(!bio_list_empty(&cell->bios));
-
- __cell_release(cell, NULL);
-}
-
-void dm_cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
-{
- unsigned long flags;
- struct dm_bio_prison *prison = cell->prison;
-
- spin_lock_irqsave(&prison->lock, flags);
- __cell_release_singleton(cell, bio);
- spin_unlock_irqrestore(&prison->lock, flags);
-}
-EXPORT_SYMBOL_GPL(dm_cell_release_singleton);
-
-/*
* Sometimes we don't want the holder, just the additional bios.
*/
static void __cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates)