dm cache: fix device destroy hang due to improper prealloc_used accounting

[cascardo/linux.git] / drivers / md / dm-cache-target.c

diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 64e96a2..1fe93cf 100644 (file)
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -1967,6 +1967,7 @@ static void process_deferred_bios(struct cache *cache)
                 * this bio might require one, we pause until there are some
                 * prepared mappings to process.
                 */
+               prealloc_used = true;
                if (prealloc_data_structs(cache, &structs)) {
                        spin_lock_irqsave(&cache->lock, flags);
                        bio_list_merge(&cache->deferred_bios, &bios);
@@ -1982,7 +1983,6 @@ static void process_deferred_bios(struct cache *cache)
                        process_discard_bio(cache, &structs, bio);
                else
                        process_bio(cache, &structs, bio);
-               prealloc_used = true;
        }
 
        if (prealloc_used)
@@ -2011,6 +2011,7 @@ static void process_deferred_cells(struct cache *cache)
                 * this bio might require one, we pause until there are some
                 * prepared mappings to process.
                 */
+               prealloc_used = true;
                if (prealloc_data_structs(cache, &structs)) {
                        spin_lock_irqsave(&cache->lock, flags);
                        list_splice(&cells, &cache->deferred_cells);
@@ -2019,7 +2020,6 @@ static void process_deferred_cells(struct cache *cache)
                }
 
                process_cell(cache, &structs, cell);
-               prealloc_used = true;
        }
 
        if (prealloc_used)
@@ -2081,6 +2081,7 @@ static void writeback_some_dirty_blocks(struct cache *cache)
                if (policy_writeback_work(cache->policy, &oblock, &cblock, busy))
                        break; /* no work to do */
 
+               prealloc_used = true;
                if (prealloc_data_structs(cache, &structs) ||
                    get_cell(cache, oblock, &structs, &old_ocell)) {
                        policy_set_dirty(cache->policy, oblock);
@@ -2088,7 +2089,6 @@ static void writeback_some_dirty_blocks(struct cache *cache)
                }
 
                writeback(cache, &structs, oblock, cblock, old_ocell);
-               prealloc_used = true;
        }
 
        if (prealloc_used)