On Wed, Dec 10, 2025 at 04:23:35PM +0100, Christoph Hellwig wrote:

Allocating a skcipher request dynamically can deadlock or cause
unexpected I/O failures when called from writeback context.  Avoid the
allocation entirely by using on-stack skciphers, similar to what the
non-blk-crypto fscrypt path already does.

This drops the incomplete support for asynchronous algorithms, which
previously could be used, but only synchronously.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-crypto-fallback.c | 178 ++++++++++++++++--------------------
 1 file changed, 79 insertions(+), 99 deletions(-)

Reviewed-by: Eric Biggers <ebiggers@kernel.org>

- Eric