From patchwork Sun Aug 13 18:26:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kent Overstreet X-Patchwork-Id: 13352208 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FF61C001B0 for ; Sun, 13 Aug 2023 18:26:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231425AbjHMS0q (ORCPT ); Sun, 13 Aug 2023 14:26:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43376 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229451AbjHMS0o (ORCPT ); Sun, 13 Aug 2023 14:26:44 -0400 Received: from out-66.mta0.migadu.com (out-66.mta0.migadu.com [91.218.175.66]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA0711708 for ; Sun, 13 Aug 2023 11:26:46 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1691951205; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=t8R8a1McseA9yHEzYOxyXGPVlvlW3Oa2+9zEDFiMSek=; b=F1iv7o3mfAJ/lx9mGer0a7rWZ9/JVBVL1z9zqJi7whLLVhox4bPxuqQxBxnC99UIfW2UlG ZBKU/hkfefnNBvH6KxiJQ+wmMFbYOXa4rcqQ5U3woeEEKzg8mLb2PEO8dFVegERyng5ghw PkMSQN64rn8tOTAYwUCtBY0YU6sq0Mk= From: Kent Overstreet To: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, axboe@kernel.dk Cc: Kent Overstreet Subject: [PATCH 2/3] block: Allow bio_iov_iter_get_pages() with bio->bi_bdev unset Date: Sun, 13 Aug 2023 14:26:35 -0400 Message-Id: <20230813182636.2966159-3-kent.overstreet@linux.dev> In-Reply-To: <20230813182636.2966159-1-kent.overstreet@linux.dev> References: <20230813182636.2966159-1-kent.overstreet@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org bio_iov_iter_get_pages() trims the IO based on the block size of the block device the IO will be issued to. However, bcachefs is a multi device filesystem; when we're creating the bio we don't yet know which block device the bio will be submitted to - we have to handle the alignment checks elsewhere. Thus this is needed to avoid a null ptr deref. Signed-off-by: Kent Overstreet Cc: Jens Axboe Cc: linux-block@vger.kernel.org --- block/bio.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/block/bio.c b/block/bio.c index 1e75840d17..e74a04ea14 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1245,7 +1245,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) struct page **pages = (struct page **)bv; ssize_t size, left; unsigned len, i = 0; - size_t offset, trim; + size_t offset; int ret = 0; /* @@ -1274,10 +1274,12 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) nr_pages = DIV_ROUND_UP(offset + size, PAGE_SIZE); - trim = size & (bdev_logical_block_size(bio->bi_bdev) - 1); - iov_iter_revert(iter, trim); + if (bio->bi_bdev) { + size_t trim = size & (bdev_logical_block_size(bio->bi_bdev) - 1); + iov_iter_revert(iter, trim); + size -= trim; + } - size -= trim; if (unlikely(!size)) { ret = -EFAULT; goto out;