summary refs log tree commit diff
path: root/drivers
diff options
context:
space:
mode:
authorMike Snitzer <snitzer@redhat.com>2015-07-16 21:26:10 -0400
committerMike Snitzer <snitzer@redhat.com>2015-07-16 22:32:07 -0400
commite782eff591bca2d96bac30ab5d1cfa4ccd3b0f86 (patch)
tree5e21539eba3903ddfee00729e38d5a006f2f2005 /drivers
parent386cb7cdeeef97e0bf082a8d6bbfc07a2ccce07b (diff)
downloadlinux-e782eff591bca2d96bac30ab5d1cfa4ccd3b0f86.tar.gz
dm cache: avoid preallocation if no work in writeback_some_dirty_blocks()
Refactor writeback_some_dirty_blocks() to avoid prealloc_data_structs()
if the policy doesn't have any dirty blocks ready for writeback.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/md/dm-cache-target.c13
1 files changed, 4 insertions, 9 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index c8a160b37412..408dd276d6c9 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -2061,7 +2061,6 @@ static void process_deferred_writethrough_bios(struct cache *cache)
 
 static void writeback_some_dirty_blocks(struct cache *cache)
 {
-	int r = 0;
 	dm_oblock_t oblock;
 	dm_cblock_t cblock;
 	struct prealloc structs;
@@ -2071,15 +2070,11 @@ static void writeback_some_dirty_blocks(struct cache *cache)
 	memset(&structs, 0, sizeof(structs));
 
 	while (spare_migration_bandwidth(cache)) {
-		if (prealloc_data_structs(cache, &structs))
-			break;
-
-		r = policy_writeback_work(cache->policy, &oblock, &cblock, busy);
-		if (r)
-			break;
+		if (policy_writeback_work(cache->policy, &oblock, &cblock, busy))
+			break; /* no work to do */
 
-		r = get_cell(cache, oblock, &structs, &old_ocell);
-		if (r) {
+		if (prealloc_data_structs(cache, &structs) ||
+		    get_cell(cache, oblock, &structs, &old_ocell)) {
 			policy_set_dirty(cache->policy, oblock);
 			break;
 		}