diff options
Diffstat (limited to 'drivers/md/dm-crypt.c')
| -rw-r--r-- | drivers/md/dm-crypt.c | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 5503e43e5f28..0f48fed44a17 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1,7 +1,7 @@ /* * Copyright (C) 2003 Jana Saout <jana@saout.de> * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> - * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved. + * Copyright (C) 2006-2015 Red Hat, Inc. All rights reserved. * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com> * * This file is released under the GPL. @@ -891,6 +891,11 @@ static void crypt_alloc_req(struct crypt_config *cc, ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO); ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]); + + /* + * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs + * requests if driver request queue is full. + */ ablkcipher_request_set_callback(ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, kcryptd_async_done, dmreq_of_req(cc, ctx->req)); @@ -924,24 +929,32 @@ static int crypt_convert(struct crypt_config *cc, r = crypt_convert_block(cc, ctx, ctx->req); switch (r) { - /* async */ + /* + * The request was queued by a crypto driver + * but the driver request queue is full, let's wait. + */ case -EBUSY: wait_for_completion(&ctx->restart); reinit_completion(&ctx->restart); - /* fall through*/ + /* fall through */ + /* + * The request is queued and processed asynchronously, + * completion function kcryptd_async_done() will be called. + */ case -EINPROGRESS: ctx->req = NULL; ctx->cc_sector++; continue; - - /* sync */ + /* + * The request was already processed (synchronously). + */ case 0: atomic_dec(&ctx->cc_pending); ctx->cc_sector++; cond_resched(); continue; - /* error */ + /* There was an error while processing the request. */ default: atomic_dec(&ctx->cc_pending); return r; @@ -1346,6 +1359,11 @@ static void kcryptd_async_done(struct crypto_async_request *async_req, struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); struct crypt_config *cc = io->cc; + /* + * A request from crypto driver backlog is going to be processed now, + * finish the completion and continue in crypt_convert(). + * (Callback will be called for the second time for this request.) + */ if (error == -EINPROGRESS) { complete(&ctx->restart); return; |