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authorEric Biggers <ebiggers@google.com>2020-09-15 20:53:13 -0700
committerJens Axboe <axboe@kernel.dk>2020-10-05 10:47:43 -0600
commit07560151db960d26b425410d6fd778e6757a5da2 (patch)
tree2d8582959d8765348d923e745a187983f6c01aaf /include/linux/blk-crypto.h
parent10ed16662da9e28a33b6c991c36c6b323b03dd5b (diff)
block: make bio_crypt_clone() able to fail
bio_crypt_clone() assumes its gfp_mask argument always includes __GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed. However, bio_crypt_clone() might be called with GFP_ATOMIC via setup_clone() in drivers/md/dm-rq.c, or with GFP_NOWAIT via kcryptd_io_read() in drivers/md/dm-crypt.c. Neither case is currently reachable with a bio that actually has an encryption context. However, it's fragile to rely on this. Just make bio_crypt_clone() able to fail, analogous to bio_integrity_clone(). Reported-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Satya Tangirala <satyat@google.com> Cc: Satya Tangirala <satyat@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux/blk-crypto.h')
-rw-r--r--include/linux/blk-crypto.h20
1 files changed, 16 insertions, 4 deletions
diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h
index e82342907f2b..69b24fe92cbf 100644
--- a/include/linux/blk-crypto.h
+++ b/include/linux/blk-crypto.h
@@ -112,12 +112,24 @@ static inline bool bio_has_crypt_ctx(struct bio *bio)
#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
-void __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask);
-static inline void bio_crypt_clone(struct bio *dst, struct bio *src,
- gfp_t gfp_mask)
+int __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask);
+/**
+ * bio_crypt_clone - clone bio encryption context
+ * @dst: destination bio
+ * @src: source bio
+ * @gfp_mask: memory allocation flags
+ *
+ * If @src has an encryption context, clone it to @dst.
+ *
+ * Return: 0 on success, -ENOMEM if out of memory. -ENOMEM is only possible if
+ * @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM.
+ */
+static inline int bio_crypt_clone(struct bio *dst, struct bio *src,
+ gfp_t gfp_mask)
{
if (bio_has_crypt_ctx(src))
- __bio_crypt_clone(dst, src, gfp_mask);
+ return __bio_crypt_clone(dst, src, gfp_mask);
+ return 0;
}
#endif /* __LINUX_BLK_CRYPTO_H */