bcache: check CACHE_SET_IO_DISABLE in allocator code

[ Upstream commit e775339 ] 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 <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
pelwell · Jul 26, 2019 · 57cfb75 · 57cfb75
1 parent e78d1d2
commit 57cfb75
Showing 1 changed file with 9 additions and 0 deletions.
diff --git 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 > 8);