From patchwork Wed Sep 16 03:53:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11778903 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1F666746 for ; Wed, 16 Sep 2020 03:54:24 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B7746221E3 for ; Wed, 16 Sep 2020 03:54:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7746221E3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=dm-devel-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-122-ruBLx-MyNEW9qc4GIPBpWw-1; Tue, 15 Sep 2020 23:54:19 -0400 X-MC-Unique: ruBLx-MyNEW9qc4GIPBpWw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8434E801AAB; Wed, 16 Sep 2020 03:54:15 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 464255DE51; Wed, 16 Sep 2020 03:54:15 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 8DB3B44A5B; Wed, 16 Sep 2020 03:54:14 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 08G3sCXt001347 for ; Tue, 15 Sep 2020 23:54:12 -0400 Received: by smtp.corp.redhat.com (Postfix) id 7956E2024508; Wed, 16 Sep 2020 03:54:12 +0000 (UTC) Delivered-To: dm-devel@redhat.com Received: from mimecast-mx02.redhat.com (mimecast03.extmail.prod.ext.rdu2.redhat.com [10.11.55.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 74E3720244F7 for ; Wed, 16 Sep 2020 03:54:10 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 56DC288907A for ; Wed, 16 Sep 2020 03:54:10 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-371-jUDkuFbyPBq42LF_YbsihA-1; Tue, 15 Sep 2020 23:54:08 -0400 X-MC-Unique: jUDkuFbyPBq42LF_YbsihA-1 Received: from sol.attlocal.net (172-10-235-113.lightspeed.sntcca.sbcglobal.net [172.10.235.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AF638221E5; Wed, 16 Sep 2020 03:54:06 +0000 (UTC) From: Eric Biggers To: linux-block@vger.kernel.org, Jens Axboe Date: Tue, 15 Sep 2020 20:53:14 -0700 Message-Id: <20200916035315.34046-3-ebiggers@kernel.org> In-Reply-To: <20200916035315.34046-1-ebiggers@kernel.org> References: <20200916035315.34046-1-ebiggers@kernel.org> MIME-Version: 1.0 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false; X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-MIME-Autoconverted: from quoted-printable to 8bit by lists01.pubmisc.prod.ext.phx2.redhat.com id 08G3sCXt001347 X-loop: dm-devel@redhat.com Cc: Miaohe Lin , dm-devel@redhat.com, Satya Tangirala Subject: [dm-devel] [PATCH v2 2/3] block: make blk_crypto_rq_bio_prep() able to fail X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com From: Eric Biggers blk_crypto_rq_bio_prep() assumes its gfp_mask argument always includes __GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed. However, blk_crypto_rq_bio_prep() might be called with GFP_ATOMIC via setup_clone() in drivers/md/dm-rq.c. This case isn't currently reachable with a bio that actually has an encryption context. However, it's fragile to rely on this. Just make blk_crypto_rq_bio_prep() able to fail. Cc: Miaohe Lin Suggested-by: Satya Tangirala Signed-off-by: Eric Biggers Reviewed-by: Satya Tangirala Reviewed-by: Mike Snitzer --- block/blk-core.c | 8 +++++--- block/blk-crypto-internal.h | 21 ++++++++++++++++----- block/blk-crypto.c | 18 +++++++----------- block/blk-mq.c | 7 ++++++- 4 files changed, 34 insertions(+), 20 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index ca3f0f00c9435..fbeaa49f6fe2c 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1620,8 +1620,10 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, if (rq->bio) { rq->biotail->bi_next = bio; rq->biotail = bio; - } else + } else { rq->bio = rq->biotail = bio; + } + bio = NULL; } /* Copy attributes of the original request to the clone request. */ @@ -1634,8 +1636,8 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, rq->nr_phys_segments = rq_src->nr_phys_segments; rq->ioprio = rq_src->ioprio; - if (rq->bio) - blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask); + if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0) + goto free_and_out; return 0; diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h index d2b0f565d83cb..0d36aae538d7b 100644 --- a/block/blk-crypto-internal.h +++ b/block/blk-crypto-internal.h @@ -142,13 +142,24 @@ static inline void blk_crypto_free_request(struct request *rq) __blk_crypto_free_request(rq); } -void __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, - gfp_t gfp_mask); -static inline void blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, - gfp_t gfp_mask) +int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, + gfp_t gfp_mask); +/** + * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio + * is inserted + * @rq: The request to prepare + * @bio: The first bio being inserted into the request + * @gfp_mask: Memory allocation flags + * + * 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 blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, + gfp_t gfp_mask) { if (bio_has_crypt_ctx(bio)) - __blk_crypto_rq_bio_prep(rq, bio, gfp_mask); + return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask); + return 0; } /** diff --git a/block/blk-crypto.c b/block/blk-crypto.c index a3f27a19067c9..bbe7974fd74f0 100644 --- a/block/blk-crypto.c +++ b/block/blk-crypto.c @@ -283,20 +283,16 @@ bool __blk_crypto_bio_prep(struct bio **bio_ptr) return false; } -/** - * __blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio - * is inserted - * - * @rq: The request to prepare - * @bio: The first bio being inserted into the request - * @gfp_mask: gfp mask - */ -void __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, - gfp_t gfp_mask) +int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, + gfp_t gfp_mask) { - if (!rq->crypt_ctx) + if (!rq->crypt_ctx) { rq->crypt_ctx = mempool_alloc(bio_crypt_ctx_pool, gfp_mask); + if (!rq->crypt_ctx) + return -ENOMEM; + } *rq->crypt_ctx = *bio->bi_crypt_context; + return 0; } /** diff --git a/block/blk-mq.c b/block/blk-mq.c index e04b759add758..9ec0e7149ae69 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1940,13 +1940,18 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) static void blk_mq_bio_to_request(struct request *rq, struct bio *bio, unsigned int nr_segs) { + int err; + if (bio->bi_opf & REQ_RAHEAD) rq->cmd_flags |= REQ_FAILFAST_MASK; rq->__sector = bio->bi_iter.bi_sector; rq->write_hint = bio->bi_write_hint; blk_rq_bio_prep(rq, bio, nr_segs); - blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO); + + /* This can't fail, since GFP_NOIO includes __GFP_DIRECT_RECLAIM. */ + err = blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO); + WARN_ON_ONCE(err); blk_account_io_start(rq); }