dm thin: allocate the cell_sort_array dynamically
Given the pool's cell_sort_array holds 8192 pointers it triggers an
order 5 allocation via kmalloc. This order 5 allocation is prone to
failure as system memory gets more fragmented over time.
Fix this by allocating the cell_sort_array using vmalloc.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index c33f61a4..8f015d9 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -18,6 +18,7 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/vmalloc.h>
#include <linux/sort.h>
#include <linux/rbtree.h>
@@ -268,7 +269,7 @@
process_mapping_fn process_prepared_mapping;
process_mapping_fn process_prepared_discard;
- struct dm_bio_prison_cell *cell_sort_array[CELL_SORT_ARRAY_SIZE];
+ struct dm_bio_prison_cell **cell_sort_array;
};
static enum pool_mode get_pool_mode(struct pool *pool);
@@ -2777,6 +2778,7 @@
{
__pool_table_remove(pool);
+ vfree(pool->cell_sort_array);
if (dm_pool_metadata_close(pool->pmd) < 0)
DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
@@ -2889,6 +2891,13 @@
goto bad_mapping_pool;
}
+ pool->cell_sort_array = vmalloc(sizeof(*pool->cell_sort_array) * CELL_SORT_ARRAY_SIZE);
+ if (!pool->cell_sort_array) {
+ *error = "Error allocating cell sort array";
+ err_p = ERR_PTR(-ENOMEM);
+ goto bad_sort_array;
+ }
+
pool->ref_count = 1;
pool->last_commit_jiffies = jiffies;
pool->pool_md = pool_md;
@@ -2897,6 +2906,8 @@
return pool;
+bad_sort_array:
+ mempool_destroy(pool->mapping_pool);
bad_mapping_pool:
dm_deferred_set_destroy(pool->all_io_ds);
bad_all_io_ds: