From patchwork Fri Jan 20 16:25:26 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Farman X-Patchwork-Id: 9528931 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E90C660434 for ; Fri, 20 Jan 2017 16:27:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C4F7828695 for ; Fri, 20 Jan 2017 16:27:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B72112868F; Fri, 20 Jan 2017 16:27:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4E10F2868F for ; Fri, 20 Jan 2017 16:27:24 +0000 (UTC) Received: from localhost ([::1]:55826 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cUc27-0006Aj-D5 for patchwork-qemu-devel@patchwork.kernel.org; Fri, 20 Jan 2017 11:27:23 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40828) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cUc11-0005eI-J2 for qemu-devel@nongnu.org; Fri, 20 Jan 2017 11:26:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cUc0x-0000xp-Gw for qemu-devel@nongnu.org; Fri, 20 Jan 2017 11:26:15 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:56619 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cUc0x-0000xN-CT for qemu-devel@nongnu.org; Fri, 20 Jan 2017 11:26:11 -0500 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v0KGQ2nU035324 for ; Fri, 20 Jan 2017 11:26:10 -0500 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0b-001b2d01.pphosted.com with ESMTP id 283hjm2tkw-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 20 Jan 2017 11:26:10 -0500 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Fri, 20 Jan 2017 16:25:30 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 0723017D805F; Fri, 20 Jan 2017 16:28:25 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v0KGPTxe53215436; Fri, 20 Jan 2017 16:25:29 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DDBBA4C07E; Fri, 20 Jan 2017 16:25:28 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CD0D64C081; Fri, 20 Jan 2017 16:25:28 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Fri, 20 Jan 2017 16:25:28 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 4958) id 14FFC20F5CF; Fri, 20 Jan 2017 17:25:29 +0100 (CET) From: Eric Farman To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Fri, 20 Jan 2017 17:25:26 +0100 X-Mailer: git-send-email 2.8.4 In-Reply-To: <20170120162527.66075-1-farman@linux.vnet.ibm.com> References: <20170120162527.66075-1-farman@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17012016-0040-0000-0000-0000031ADC48 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17012016-0041-0000-0000-000023E2EC5A Message-Id: <20170120162527.66075-3-farman@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-01-20_12:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1701200222 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.158.5 Subject: [Qemu-devel] [PATCH v3 2/3] block: Fix target variable of BLKSECTGET ioctl X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eric Farman , kwolf@redhat.com, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Commit 6f6071745bd0 ("raw-posix: Fetch max sectors for host block device") introduced a routine to call the kernel BLKSECTGET ioctl, which stores the result back to user space. However, the size of the data returned depends on the routine handling the ioctl. The (compat_)blkdev_ioctl returns a short, while sg_ioctl returns an int. Thus, on big-endian systems, we can find ourselves accidentally shifting the result to a much larger value. (On s390x, a short is 16 bits while an int is 32 bits.) Also, the two ioctl handlers return values in different scales (block returns sectors, while sg returns bytes), so some tweaking of the outputs is required such that hdev_get_max_transfer_length returns a value in a consistent set of units. Signed-off-by: Eric Farman --- block/file-posix.c | 17 ++++++++++------- include/block/block.h | 1 + 2 files changed, 11 insertions(+), 7 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 28b47d9..9f83725 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -651,12 +651,15 @@ static void raw_reopen_abort(BDRVReopenState *state) state->opaque = NULL; } -static int hdev_get_max_transfer_length(int fd) +static int hdev_get_max_transfer_length(BlockDriverState *bs, int fd) { #ifdef BLKSECTGET - int max_sectors = 0; - if (ioctl(fd, BLKSECTGET, &max_sectors) == 0) { - return max_sectors; + int max_bytes = 0; + short max_sectors = 0; + if (bs->sg && ioctl(fd, BLKSECTGET, &max_bytes) == 0) { + return max_bytes; + } else if (!bs->sg && ioctl(fd, BLKSECTGET, &max_sectors) == 0) { + return max_sectors << BDRV_SECTOR_BITS; } else { return -errno; } @@ -672,9 +675,9 @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp) if (!fstat(s->fd, &st)) { if (S_ISBLK(st.st_mode)) { - int ret = hdev_get_max_transfer_length(s->fd); - if (ret > 0 && ret <= BDRV_REQUEST_MAX_SECTORS) { - bs->bl.max_transfer = pow2floor(ret << BDRV_SECTOR_BITS); + int ret = hdev_get_max_transfer_length(bs, s->fd); + if (ret > 0 && ret <= BDRV_REQUEST_MAX_BYTES) { + bs->bl.max_transfer = pow2floor(ret); } } } diff --git a/include/block/block.h b/include/block/block.h index 8b0dcda..4e81f20 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -116,6 +116,7 @@ typedef struct HDGeometry { #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \ INT_MAX >> BDRV_SECTOR_BITS) +#define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) /* * Allocation status flags