diff options
| author | Joe Thornber <ejt@redhat.com> | 2012-12-21 20:23:31 +0000 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2012-12-21 20:23:31 +0000 |
| commit | b7ca9c9273e5eebd63880dd8a6e4e5c18fc7901d (patch) | |
| tree | 8022d8d5f6f03d80896407562b48c554a8cbfa6f /drivers/md/dm-bio-prison.c | |
| parent | c1a94672a830e01d58c7c7e8de530c3f136d6ff2 (diff) | |
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.c | 25 |
1 files changed, 0 insertions, 25 deletions
diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c index e4e84156745..aefb78e3cbf 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) |