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: 11778895 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 1EC50746 for ; Wed, 16 Sep 2020 03:54:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0674A22207 for ; Wed, 16 Sep 2020 03:54:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600228457; bh=3YnrepG0AoOP07GUAq1nq3E1pIVE5+36kfYE5z5wXGk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=p09yuUajTFaBhT5euoSyl8E0OGtzrhX20Kn7dWDyzM67eyM4jvVdSxdx/oiPvCSCS NvdINzCsTgQP6eDUSUMl8ZD9SRIA8ju67IZytJmKSNIJBfILwCNJbRl3ta3nLHYjIE o6I4EZLfbdoeZNGS2Nx+dWnJGw34eG9BDtLyJVSs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726133AbgIPDyN (ORCPT ); Tue, 15 Sep 2020 23:54:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:50384 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726125AbgIPDyH (ORCPT ); Tue, 15 Sep 2020 23:54:07 -0400 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) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600228446; bh=3YnrepG0AoOP07GUAq1nq3E1pIVE5+36kfYE5z5wXGk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1CbJITxFpguU2m/lUQTS9SdTngkkcyaXDywEXO85xA7RTNucFaYd3mnpNixjzpiPg HrfFnnVcxvdxHJXgupsvpM56L6s+j5DsRW1NS9TwH3h3oD1B23iJHUUnc1ITCh5QHk ApE2wnUw3oowhCpU5hlrtS/T4KWuvxcU2aOhymNM= From: Eric Biggers To: linux-block@vger.kernel.org, Jens Axboe Cc: dm-devel@redhat.com, Satya Tangirala , Miaohe Lin Subject: [PATCH v2 2/3] block: make blk_crypto_rq_bio_prep() able to fail Date: Tue, 15 Sep 2020 20:53:14 -0700 Message-Id: <20200916035315.34046-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200916035315.34046-1-ebiggers@kernel.org> References: <20200916035315.34046-1-ebiggers@kernel.org> MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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); }