3.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ben Collins <ben.c@xxxxxxxxxxxx>
commit 0618764cb25f6fa9fb31152995de42a8a0496475 upstream.
I suspect this doesn't show up for most anyone because software
algorithms typically don't have a sense of being too busy. However,
when working with the Freescale CAAM driver it will return -EBUSY on
occasion under heavy -- which resulted in dm-crypt deadlock.
After checking the logic in some other drivers, the scheme for
crypt_convert() and it's callback, kcryptd_async_done(), were not
correctly laid out to properly handle -EBUSY or -EINPROGRESS.
Fix this by using the completion for both -EBUSY and -EINPROGRESS. Now
crypt_convert()'s use of completion is comparable to
af_alg_wait_for_completion(). Similarly, kcryptd_async_done() follows
the pattern used in af_alg_complete().
Before this fix dm-crypt would lockup within 1-2 minutes running with
the CAAM driver. Fix was regression tested against software algorithms
on PPC32 and x86_64, and things seem perfectly happy there as well.
Signed-off-by: Ben Collins <ben.c@xxxxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-crypt.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -915,11 +915,10 @@ static int crypt_convert(struct crypt_co
switch (r) {
/* async */
+ case -EINPROGRESS:
case -EBUSY:
wait_for_completion(&ctx->restart);
reinit_completion(&ctx->restart);
- /* fall through*/
- case -EINPROGRESS:
ctx->req = NULL;
ctx->cc_sector++;
continue;
@@ -1314,10 +1313,8 @@ static void kcryptd_async_done(struct cr
struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
struct crypt_config *cc = io->cc;
- if (error == -EINPROGRESS) {
- complete(&ctx->restart);
+ if (error == -EINPROGRESS)
return;
- }
if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
@@ -1328,12 +1325,15 @@ static void kcryptd_async_done(struct cr
mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool);
if (!atomic_dec_and_test(&ctx->cc_pending))
- return;
+ goto done;
if (bio_data_dir(io->base_bio) == READ)
kcryptd_crypt_read_done(io);
else
kcryptd_crypt_write_io_submit(io, 1);
+done:
+ if (!completion_done(&ctx->restart))
+ complete(&ctx->restart);
}
static void kcryptd_crypt(struct work_struct *work)
--
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