dm thin: remove cells from stack

This patch takes advantage of the new bio-prison interface where the
memory is now passed in rather than using a mempool in bio-prison.
This allows the map function to avoid performing potentially-blocking
allocations that could lead to deadlocks: We want to avoid the cell
allocation that is done in bio_detain.

(The potential for mempool deadlocks still remains in other functions
that use bio_detain.)

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 0 insertions, 7 deletions

diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c
index ca5771d..144067c 100644
--- a/drivers/md/dm-bio-prison.c
+++ b/drivers/md/dm-bio-prison.c
@@ -14,13 +14,6 @@
 
 /*----------------------------------------------------------------*/
 
-struct dm_bio_prison_cell {
-	struct hlist_node list;
-	struct dm_cell_key key;
-	struct bio *holder;
-	struct bio_list bios;
-};
-
 struct dm_bio_prison {
 	spinlock_t lock;
 	mempool_t *cell_pool;