From patchwork Thu Sep 29 02:19:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 9355623 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 1D53A6077A for ; Thu, 29 Sep 2016 02:19:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0DC07297BD for ; Thu, 29 Sep 2016 02:19:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 02735297BF; Thu, 29 Sep 2016 02:19:45 +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, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 85C97297BD for ; Thu, 29 Sep 2016 02:19:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755098AbcI2CTn (ORCPT ); Wed, 28 Sep 2016 22:19:43 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:20972 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754530AbcI2CTn (ORCPT ); Wed, 28 Sep 2016 22:19:43 -0400 Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id u8T2J6Tr032519 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 29 Sep 2016 02:19:06 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0021.oracle.com (8.13.8/8.13.8) with ESMTP id u8T2J5op006505 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 29 Sep 2016 02:19:06 GMT Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by aserv0121.oracle.com (8.13.8/8.13.8) with ESMTP id u8T2J2OG016989; Thu, 29 Sep 2016 02:19:04 GMT Received: from localhost (/24.21.211.40) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 28 Sep 2016 19:19:02 -0700 Date: Wed, 28 Sep 2016 19:19:00 -0700 From: "Darrick J. Wong" To: axboe@kernel.dk, akpm@linux-foundation.org Cc: hch@infradead.org, tytso@mit.edu, martin.petersen@oracle.com, snitzer@redhat.com, linux-api@vger.kernel.org, bfoster@redhat.com, xfs@oss.sgi.com, linux-block@vger.kernel.org, dm-devel@redhat.com, linux-fsdevel@vger.kernel.org, bart.vanassche@sandisk.com Subject: [PATCH v2 3/3] block: implement (some of) fallocate for block devices Message-ID: <20160929021900.GA4901@birch.djwong.org> References: <147510957066.8940.13803086684642725401.stgit@birch.djwong.org> <147510959149.8940.2897845352082568677.stgit@birch.djwong.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <147510959149.8940.2897845352082568677.stgit@birch.djwong.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP After much discussion, it seems that the fallocate feature flag FALLOC_FL_ZERO_RANGE maps nicely to SCSI WRITE SAME; and the feature FALLOC_FL_PUNCH_HOLE maps nicely to the devices that have been whitelisted for zeroing SCSI UNMAP. Punch still requires that FALLOC_FL_KEEP_SIZE is set. A length that goes past the end of the device will be clamped to the device size if KEEP_SIZE is set; or will return -EINVAL if not. Both start and length must be aligned to the device's logical block size. Since the semantics of fallocate are fairly well established already, wire up the two pieces. The other fallocate variants (collapse range, insert range, and allocate blocks) are not supported. Signed-off-by: Darrick J. Wong Reviewed-by: Bart Van Assche --- v2: Incorporate feedback from Christoph & Linus. Tentatively add a requirement that the fallocate arguments be aligned to logical block size, and put in a few XXX comments ahead of LSF discussion. v3: Forward port to 4.7. v4: Forward port to 4.8. --- fs/block_dev.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/open.c | 3 +- 2 files changed, 77 insertions(+), 1 deletion(-) -- To unsubscribe from this list: send the line "unsubscribe linux-block" 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/fs/block_dev.c b/fs/block_dev.c index 08ae993..7b6d096 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include "internal.h" @@ -1787,6 +1788,79 @@ static const struct address_space_operations def_blk_aops = { .is_dirty_writeback = buffer_check_dirty_writeback, }; +#define BLKDEV_FALLOC_FL_SUPPORTED \ + (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ + FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) + +static long blkdev_fallocate(struct file *file, int mode, loff_t start, + loff_t len) +{ + struct block_device *bdev = I_BDEV(bdev_file_inode(file)); + struct request_queue *q = bdev_get_queue(bdev); + struct address_space *mapping; + loff_t end = start + len - 1; + loff_t isize; + int error; + + /* Fail if we don't recognize the flags. */ + if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) + return -EOPNOTSUPP; + + /* Don't go off the end of the device. */ + isize = i_size_read(bdev->bd_inode); + if (start >= isize) + return -EINVAL; + if (end >= isize) { + if (mode & FALLOC_FL_KEEP_SIZE) { + len = isize - start; + end = start + len - 1; + } else + return -EINVAL; + } + + /* + * Don't allow IO that isn't aligned to logical block size. + */ + if ((start | len) & (bdev_logical_block_size(bdev) - 1)) + return -EINVAL; + + /* Invalidate the page cache, including dirty pages. */ + mapping = bdev->bd_inode->i_mapping; + truncate_inode_pages_range(mapping, start, end); + + switch (mode) { + case FALLOC_FL_ZERO_RANGE: + case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: + error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, + GFP_KERNEL, false); + break; + case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: + /* Only punch if the device can do zeroing discard. */ + if (!blk_queue_discard(q) || !q->limits.discard_zeroes_data) + return -EOPNOTSUPP; + error = blkdev_issue_discard(bdev, start >> 9, len >> 9, + GFP_KERNEL, 0); + break; + case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: + error = blkdev_issue_discard(bdev, start >> 9, len >> 9, + GFP_KERNEL, 0); + break; + default: + return -EOPNOTSUPP; + } + if (error) + return error; + + /* + * Invalidate again; if someone wandered in and dirtied a page, + * the caller will be given -EBUSY. The third argument is + * inclusive, so the rounding here is safe. + */ + return invalidate_inode_pages2_range(mapping, + start >> PAGE_SHIFT, + end >> PAGE_SHIFT); +} + const struct file_operations def_blk_fops = { .open = blkdev_open, .release = blkdev_close, @@ -1801,6 +1875,7 @@ const struct file_operations def_blk_fops = { #endif .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, + .fallocate = blkdev_fallocate, }; int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) diff --git a/fs/open.c b/fs/open.c index 4fd6e25..01b6092 100644 --- a/fs/open.c +++ b/fs/open.c @@ -289,7 +289,8 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) * Let individual file system decide if it supports preallocation * for directories or not. */ - if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) + if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode) && + !S_ISBLK(inode->i_mode)) return -ENODEV; /* Check for wrap through zero too */