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authorEric Biggers <ebiggers@google.com>2020-09-15 20:53:15 -0700
committerJens Axboe <axboe@kernel.dk>2020-10-05 10:47:43 -0600
commitcf785af19319f9fc0fc0c0604d259f1ef31b502f (patch)
treeb047fc45f79597a6943d9408e66a376483c4b5c3 /block/blk-crypto.c
parent93f221ae08381e994ac9f9ff6aa743e612e49718 (diff)
block: warn if !__GFP_DIRECT_RECLAIM in bio_crypt_set_ctx()
bio_crypt_set_ctx() assumes its gfp_mask argument always includes __GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed. For now this assumption is still fine, since no callers violate it. Making bio_crypt_set_ctx() able to fail would add unneeded complexity. However, if a caller didn't use __GFP_DIRECT_RECLAIM, it would be very hard to notice the bug. Make it easier by adding a WARN_ON_ONCE(). Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Satya Tangirala <satyat@google.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Satya Tangirala <satyat@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-crypto.c')
-rw-r--r--block/blk-crypto.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/block/blk-crypto.c b/block/blk-crypto.c
index bbe7974fd74f..5da43f0973b4 100644
--- a/block/blk-crypto.c
+++ b/block/blk-crypto.c
@@ -81,7 +81,15 @@ subsys_initcall(bio_crypt_ctx_init);
void bio_crypt_set_ctx(struct bio *bio, const struct blk_crypto_key *key,
const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], gfp_t gfp_mask)
{
- struct bio_crypt_ctx *bc = mempool_alloc(bio_crypt_ctx_pool, gfp_mask);
+ struct bio_crypt_ctx *bc;
+
+ /*
+ * The caller must use a gfp_mask that contains __GFP_DIRECT_RECLAIM so
+ * that the mempool_alloc() can't fail.
+ */
+ WARN_ON_ONCE(!(gfp_mask & __GFP_DIRECT_RECLAIM));
+
+ bc = mempool_alloc(bio_crypt_ctx_pool, gfp_mask);
bc->bc_key = key;
memcpy(bc->bc_dun, dun, sizeof(bc->bc_dun));