| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.1 117/267] dm thin: allocate the cell_sort_array dynamically | Date | Fri, 31 Jul 2015 12:39:28 -0700 |
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4.1-stable review patch. If anyone has any objections, please let me know.
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From: Joe Thornber <ejt@redhat.com>
commit a822c83e47d97cdef38c4352e1ef62d9f46cfe98 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/dm-thin.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
--- 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> @@ -260,7 +261,7 @@ struct pool { 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); @@ -2499,6 +2500,7 @@ static void __pool_destroy(struct pool * { __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__); @@ -2611,6 +2613,13 @@ static struct pool *pool_create(struct m 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; @@ -2619,6 +2628,8 @@ static struct pool *pool_create(struct m 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:
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