From patchwork Wed Nov 11 06:29:48 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 7593821 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D39A1BF90C for ; Wed, 11 Nov 2015 06:30:23 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DCD2520617 for ; Wed, 11 Nov 2015 06:30:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0F7120445 for ; Wed, 11 Nov 2015 06:30:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750869AbbKKGaT (ORCPT ); Wed, 11 Nov 2015 01:30:19 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:35197 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750778AbbKKGaS (ORCPT ); Wed, 11 Nov 2015 01:30:18 -0500 Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id tAB6TpOp006949 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 11 Nov 2015 06:29:52 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0022.oracle.com (8.13.8/8.13.8) with ESMTP id tAB6TpFE024431 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Wed, 11 Nov 2015 06:29:51 GMT Received: from abhmp0008.oracle.com (abhmp0008.oracle.com [141.146.116.14]) by userv0121.oracle.com (8.13.8/8.13.8) with ESMTP id tAB6TowB013336; Wed, 11 Nov 2015 06:29:50 GMT Received: from localhost (/24.21.154.84) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 10 Nov 2015 22:29:49 -0800 Date: Tue, 10 Nov 2015 22:29:48 -0800 From: "Darrick J. Wong" To: Jens Axboe , Christoph Hellwig Cc: "Seymour, Shane M" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-api@vger.kernel.org" , Jeff Layton , "J. Bruce Fields" , "martin.petersen@oracle.com" Subject: [PATCH v3] block: create ioctl to discard-or-zeroout a range of blocks Message-ID: <20151111062948.GA2214@birch.djwong.org> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-7.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Create a new ioctl to expose the block layer's newfound ability to issue either a zeroing discard, a WRITE SAME with a zero page, or a regular write with the zero page. This BLKZEROOUT2 ioctl takes {start, length, flags} as parameters. So far, the only flag available is to enable the zeroing discard part -- without it, the call invokes the old BLKZEROOUT behavior. start and length have the same meaning as in BLKZEROOUT. Furthermore, because BLKZEROOUT2 issues commands directly to the storage device, we must invalidate the page cache (as a regular O_DIRECT write would do) to avoid returning stale cache contents at a later time. v3: Add extra padding for future expansion, and check the padding is zero. Signed-off-by: Darrick J. Wong --- block/ioctl.c | 48 ++++++++++++++++++++++++++++++++++++++++------- include/uapi/linux/fs.h | 9 +++++++++ 2 files changed, 50 insertions(+), 7 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/block/ioctl.c b/block/ioctl.c index 8061eba..8e67551 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -213,19 +213,39 @@ static int blk_ioctl_discard(struct block_device *bdev, uint64_t start, } static int blk_ioctl_zeroout(struct block_device *bdev, uint64_t start, - uint64_t len) + uint64_t len, uint32_t flags) { + int ret; + struct address_space *mapping; + uint64_t end = start + len - 1; + + if (flags & ~BLKZEROOUT2_DISCARD_OK) + return -EINVAL; if (start & 511) return -EINVAL; if (len & 511) return -EINVAL; - start >>= 9; - len >>= 9; - - if (start + len > (i_size_read(bdev->bd_inode) >> 9)) + if (end >= i_size_read(bdev->bd_inode)) return -EINVAL; - return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false); + /* Invalidate the page cache, including dirty pages */ + mapping = bdev->bd_inode->i_mapping; + truncate_inode_pages_range(mapping, start, end); + + ret = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL, + flags & BLKZEROOUT2_DISCARD_OK); + if (ret) + goto out; + + /* + * Invalidate again; if someone wandered in and dirtied a page, + * the caller will be given -EBUSY. + */ + ret = invalidate_inode_pages2_range(mapping, + start >> PAGE_CACHE_SHIFT, + end >> PAGE_CACHE_SHIFT); +out: + return ret; } static int put_ushort(unsigned long arg, unsigned short val) @@ -353,7 +373,21 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, if (copy_from_user(range, (void __user *)arg, sizeof(range))) return -EFAULT; - return blk_ioctl_zeroout(bdev, range[0], range[1]); + return blk_ioctl_zeroout(bdev, range[0], range[1], 0); + } + case BLKZEROOUT2: { + struct blkzeroout2 p; + + if (!(mode & FMODE_WRITE)) + return -EBADF; + + if (copy_from_user(&p, (void __user *)arg, sizeof(p))) + return -EFAULT; + + if (p.padding || p.padding2) + return -EINVAL; + + return blk_ioctl_zeroout(bdev, p.start, p.length, p.flags); } case HDIO_GETGEO: { diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 9b964a5..b811fa4 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -152,6 +152,15 @@ struct inodes_stat_t { #define BLKSECDISCARD _IO(0x12,125) #define BLKROTATIONAL _IO(0x12,126) #define BLKZEROOUT _IO(0x12,127) +struct blkzeroout2 { + __u64 start; + __u64 length; + __u32 flags; + __u32 padding; + __u64 padding2; +}; +#define BLKZEROOUT2_DISCARD_OK 1 +#define BLKZEROOUT2 _IOR(0x12, 127, struct blkzeroout2) #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */ #define FIBMAP _IO(0x00,1) /* bmap access */