From e775339e1ae1205b47d94881db124c11385e597c Mon Sep 17 00:00:00 2001 From: Coly Li Date: Fri, 28 Jun 2019 19:59:35 +0800 Subject: [PATCH] bcache: check CACHE_SET_IO_DISABLE in allocator code If CACHE_SET_IO_DISABLE of a cache set flag is set by too many I/O errors, currently allocator routines can still continue allocate space which may introduce inconsistent metadata state. This patch checkes CACHE_SET_IO_DISABLE bit in following allocator routines, - bch_bucket_alloc() - __bch_bucket_alloc_set() Once CACHE_SET_IO_DISABLE is set on cache set, the allocator routines may reject allocation request earlier to avoid potential inconsistent metadata. Signed-off-by: Coly Li Signed-off-by: Jens Axboe --- drivers/md/bcache/alloc.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c index f8986effcb50..6f776823b9ba 100644 --- a/drivers/md/bcache/alloc.c +++ b/drivers/md/bcache/alloc.c @@ -393,6 +393,11 @@ long bch_bucket_alloc(struct cache *ca, unsigned int reserve, bool wait) struct bucket *b; long r; + + /* No allocation if CACHE_SET_IO_DISABLE bit is set */ + if (unlikely(test_bit(CACHE_SET_IO_DISABLE, &ca->set->flags))) + return -1; + /* fastpath */ if (fifo_pop(&ca->free[RESERVE_NONE], r) || fifo_pop(&ca->free[reserve], r)) @@ -484,6 +489,10 @@ int __bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve, { int i; + /* No allocation if CACHE_SET_IO_DISABLE bit is set */ + if (unlikely(test_bit(CACHE_SET_IO_DISABLE, &c->flags))) + return -1; + lockdep_assert_held(&c->bucket_lock); BUG_ON(!n || n > c->caches_loaded || n > MAX_CACHES_PER_SET); -- 2.30.2