From c954ac8d6610255b2fb11a30fb9ebb206f3da48d Mon Sep 17 00:00:00 2001 From: Coly Li Date: Sat, 25 Jul 2020 20:00:32 +0800 Subject: bcache: handle cache prio_buckets and disk_buckets properly for bucket size > 8MB Similar to c->uuids, struct cache's prio_buckets and disk_buckets also have the potential memory allocation failure during cache registration if the bucket size > 8MB. ca->prio_buckets can be stored on cache device in multiple buckets, its in-memory space is allocated by kzalloc() interface but normally allocated by alloc_pages() because the size > KMALLOC_MAX_CACHE_SIZE. So allocation of ca->prio_buckets has the MAX_ORDER restriction too. If the bucket size > 8MB, by default the page allocator will fail because the page order > 11 (default MAX_ORDER value). ca->prio_buckets should also use meta_bucket_bytes(), meta_bucket_pages() to decide its memory size and use alloc_meta_bucket_pages() to allocate pages, to avoid the allocation failure during cache set registration when bucket size > 8MB. ca->disk_buckets is a single bucket size memory buffer, it is used to iterate each bucket of ca->prio_buckets, and compose the bio based on memory of ca->disk_buckets, then write ca->disk_buckets memory to cache disk one-by-one for each bucket of ca->prio_buckets. ca->disk_buckets should have in-memory size exact to the meta_bucket_pages(), this is the size that ca->prio_buckets will be stored into each on-disk bucket. This patch fixes the above issues and handle cache's prio_buckets and disk_buckets properly for bucket size larger than 8MB. Signed-off-by: Coly Li Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/md/bcache/bcache.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'drivers/md/bcache/bcache.h') diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index 5e1c581137af..4fd03d2496d8 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -782,11 +782,12 @@ static inline unsigned int meta_bucket_bytes(struct cache_sb *sb) return meta_bucket_pages(sb) << PAGE_SHIFT; } -#define prios_per_bucket(c) \ - ((bucket_bytes(c) - sizeof(struct prio_set)) / \ +#define prios_per_bucket(ca) \ + ((meta_bucket_bytes(&(ca)->sb) - sizeof(struct prio_set)) / \ sizeof(struct bucket_disk)) -#define prio_buckets(c) \ - DIV_ROUND_UP((size_t) (c)->sb.nbuckets, prios_per_bucket(c)) + +#define prio_buckets(ca) \ + DIV_ROUND_UP((size_t) (ca)->sb.nbuckets, prios_per_bucket(ca)) static inline size_t sector_to_bucket(struct cache_set *c, sector_t s) { -- cgit v1.2.3