On Tue, May 23 2023 at 3:58P -0400, Duoming Zhou <duoming@xxxxxxxxxx> wrote: > In order to improve the IO performance of the dm-crypt > implementation, the commit 39d42fa96ba1 ("dm crypt: > add flags to optionally bypass kcryptd workqueues") > adds tasklet to do the crypto operations. > > The tasklet callback function kcryptd_crypt_tasklet() > calls kcryptd_crypt() which is an original workqueue > callback function that may sleep. As a result, the > sleep-in-atomic-context bug may happen. The process > is shown below. > > (atomic context) > kcryptd_crypt_tasklet() > kcryptd_crypt() > kcryptd_crypt_write_convert() > wait_for_completion() //may sleep > > The wait_for_completion() is a function that may sleep. > In order to mitigate the bug, this patch changes > wait_for_completion() to try_wait_for_completion(). > > Fixes: 39d42fa96ba1 ("dm crypt: add flags to optionally bypass kcryptd workqueues") > Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx> > --- > drivers/md/dm-crypt.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c > index 8b47b913ee8..5e2b2463d87 100644 > --- a/drivers/md/dm-crypt.c > +++ b/drivers/md/dm-crypt.c > @@ -2085,7 +2085,8 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) > crypt_finished = atomic_dec_and_test(&ctx->cc_pending); > if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) { > /* Wait for completion signaled by kcryptd_async_done() */ > - wait_for_completion(&ctx->restart); > + while (!try_wait_for_completion(&ctx->restart)) > + ; > crypt_finished = 1; > } > > -- > 2.17.1 > Cc'ing Ignat for closer review. But wasn't this already addressed with this commit?: 8abec36d1274 dm crypt: do not wait for backlogged crypto request completion in softirq Mike -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel