[PATCH 15/15] bcache: panic fix for making cache device
From: Coly Li <hidden>
Date: 2018-10-08 12:41:21
Subsystem:
bcache (block layer cache), the rest · Maintainers:
Coly Li, Kent Overstreet, Linus Torvalds
From: Dongbo Cao <redacted> 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. Reported-by: nitroxis <redacted> Signed-off-by: Dongbo Cao <redacted> Signed-off-by: Coly Li <redacted> --- drivers/md/bcache/super.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 2a362a7ba995..563f75686100 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c@@ -2070,6 +2070,11 @@ 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)) {
@@ -2147,6 +2152,7 @@ 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);
@@ -2176,6 +2182,8 @@ 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;
--
2.19.0