On 9/25/18 2:09 PM, Dongbo Cao wrote:
when the nbuckets of cache device is smaller than 1024, making cache device will trigger BUG_ON in kernel, add a condition to avoid this.
Signed-off-by: Dongbo Cao <cdbdyx@xxxxxxx>
This patch added to my for-next, with minor change to fix checkpatch.pl
warning.
Thanks.
Coly Li
---
drivers/md/bcache/super.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 0c0f6d8f..47d122ed 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2036,7 +2036,12 @@ static int cache_alloc(struct cache *ca)
*/
btree_buckets = ca->sb.njournal_buckets ?: 8;
free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
-
+ if (!free) {
+ ret = -EPERM;
+ err = "ca->sb.nbuckets is too small";
+ goto err_free;
+ }
+
if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets,
GFP_KERNEL)) {
err = "ca->free[RESERVE_BTREE] alloc failed";
@@ -2102,6 +2107,7 @@ static int cache_alloc(struct cache *ca)
err_prio_alloc:
free_fifo(&ca->free[RESERVE_BTREE]);
err_btree_alloc:
+err_free:
module_put(THIS_MODULE);
if (err)
pr_notice("error %s: %s", ca->cache_dev_name, err);
@@ -2131,6 +2137,8 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
if (ret == -ENOMEM)
err = "cache_alloc(): -ENOMEM";
+ else if (ret == -EPERM)
+ err = "cache_alloc(): cache device is too small";
else
err = "cache_alloc(): unknown error";
goto err;
