From patchwork Fri Jul 10 14:21:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 11656795 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 21F0A913 for ; Fri, 10 Jul 2020 14:24:01 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EBF4B207D0 for ; Fri, 10 Jul 2020 14:24:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Fdat+49w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EBF4B207D0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:36716 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jttwW-0005OI-8t for patchwork-qemu-devel@patchwork.kernel.org; Fri, 10 Jul 2020 10:24:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41110) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jttui-0002qw-0a for qemu-devel@nongnu.org; Fri, 10 Jul 2020 10:22:08 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:27001 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jttuf-0004LO-B8 for qemu-devel@nongnu.org; Fri, 10 Jul 2020 10:22:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594390924; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rgBMF4rLOlQh9wroKSJAZ4DRUD3Yfbi2jLwdpSlmMG0=; b=Fdat+49w2K46NdeqEbbqfzQqFme1PeusfVdE4YcdX/6OoIV0jlCp8cIFJsiHiLa3V3TJNm 2hYe2DswbtOnIeMDbpNWeh7YoALGdnzSWxSxRbzK96YSaZy7DO3QHrekGYQWa6+zKSeI4j 34U/oZy5wKQK1Q7hYkL9LYjJmBuOlWY= 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-382-W5ccL0ZINTSt8tsDYgCktA-1; Fri, 10 Jul 2020 10:22:02 -0400 X-MC-Unique: W5ccL0ZINTSt8tsDYgCktA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8521EE924; Fri, 10 Jul 2020 14:22:01 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-114-57.ams2.redhat.com [10.36.114.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8EA5960C05; Fri, 10 Jul 2020 14:21:58 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH for-5.1 1/2] block: Require aligned image size to avoid assertion failure Date: Fri, 10 Jul 2020 16:21:48 +0200 Message-Id: <20200710142149.40962-2-kwolf@redhat.com> In-Reply-To: <20200710142149.40962-1-kwolf@redhat.com> References: <20200710142149.40962-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.61; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/09 22:08:55 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, nsoffer@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Unaligned requests will automatically be aligned to bl.request_alignment and we don't want to extend requests to access space beyond the end of the image, so it's required that the image size is aligned. With write requests, this could cause assertion failures like this if RESIZE permissions weren't requested: qemu-img: block/io.c:1910: bdrv_co_write_req_prepare: Assertion `end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE' failed. This was e.g. triggered by qemu-img converting to a target image with 4k request alignment when the image was only aligned to 512 bytes, but not to 4k. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake --- block.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/block.c b/block.c index cc377d7ef3..c635777911 100644 --- a/block.c +++ b/block.c @@ -1489,6 +1489,16 @@ static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv, return -EINVAL; } + /* + * Unaligned requests will automatically be aligned to bl.request_alignment + * and we don't want to extend requests to access space beyond the end of + * the image, so it's required that the image size is aligned. + */ + if ((bs->total_sectors * BDRV_SECTOR_SIZE) % bs->bl.request_alignment) { + error_setg(errp, "Image size is not a multiple of request alignment"); + return -EINVAL; + } + assert(bdrv_opt_mem_align(bs) != 0); assert(bdrv_min_mem_align(bs) != 0); assert(is_power_of_2(bs->bl.request_alignment)); From patchwork Fri Jul 10 14:21:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 11656793 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 4460A913 for ; 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Fri, 10 Jul 2020 10:22:12 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:44601 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jttui-0004Lw-CP for qemu-devel@nongnu.org; Fri, 10 Jul 2020 10:22:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594390927; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xeCWO/h8stA7OacnvuFCi1Lq98xknFoku/3saGS+ACA=; b=PhJILv/C6oAg2BAATxjJEKnnjSuqBAjtOF9QCyE5tsYPJVWogQxPTvW1vJjEnx23cUsrzi Qf7MAvsqSoEfo5WYufzmfQOnwSFTOHw5xUdGfb15dpigUNdWX1kGkNV5LZ2zyh6mk5ObN5 /wrCbccJwk5AFvIRuJLKkRezwd2NlTA= 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-485-BnpXMLsdP3SPgn472mL0eQ-1; Fri, 10 Jul 2020 10:22:06 -0400 X-MC-Unique: BnpXMLsdP3SPgn472mL0eQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E54801083E89; Fri, 10 Jul 2020 14:22:04 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-114-57.ams2.redhat.com [10.36.114.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id CC2D460C05; Fri, 10 Jul 2020 14:22:01 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH for-5.1 2/2] file-posix: Allow byte-aligned O_DIRECT with NFS Date: Fri, 10 Jul 2020 16:21:49 +0200 Message-Id: <20200710142149.40962-3-kwolf@redhat.com> In-Reply-To: <20200710142149.40962-1-kwolf@redhat.com> References: <20200710142149.40962-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.120; envelope-from=kwolf@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/10 00:36:21 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, nsoffer@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Since commit a6b257a08e3 ('file-posix: Handle undetectable alignment'), we assume that if we open a file with O_DIRECT and alignment probing returns 1, we just couldn't find out the real alignment requirement because some filesystems make the requirement only for allocated blocks. In this case, a safe default of 4k is used. This is too strict NFS, which does actually allow byte-aligned requests even with O_DIRECT. Because we can't distinguish both cases with generic code, let's just look at the file system magic and disable s->needs_alignment for NFS. This way, O_DIRECT can still be used on NFS for images that are not aligned to 4k. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake --- block/file-posix.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/block/file-posix.c b/block/file-posix.c index 0c4e07c415..4e9dac461b 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -62,10 +62,12 @@ #include #include #include +#include #include #include #include #include +#include #include #ifdef __s390__ #include @@ -300,6 +302,28 @@ static int probe_physical_blocksize(int fd, unsigned int *blk_size) #endif } +/* + * Returns true if no alignment restrictions are necessary even for files + * opened with O_DIRECT. + * + * raw_probe_alignment() probes the required alignment and assume that 1 means + * the probing failed, so it falls back to a safe default of 4k. This can be + * avoided if we know that byte alignment is okay for the file. + */ +static bool dio_byte_aligned(int fd) +{ +#ifdef __linux__ + struct statfs buf; + int ret; + + ret = fstatfs(fd, &buf); + if (ret == 0 && buf.f_type == NFS_SUPER_MAGIC) { + return true; + } +#endif + return false; +} + /* Check if read is allowed with given memory buffer and length. * * This function is used to check O_DIRECT memory buffer and request alignment. @@ -631,7 +655,7 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->has_discard = true; s->has_write_zeroes = true; - if ((bs->open_flags & BDRV_O_NOCACHE) != 0) { + if ((bs->open_flags & BDRV_O_NOCACHE) != 0 && !dio_byte_aligned(s->fd)) { s->needs_alignment = true; }