Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932355AbbGCOlX (ORCPT ); Fri, 3 Jul 2015 10:41:23 -0400 Received: from mga03.intel.com ([134.134.136.65]:6847 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755058AbbGCOk5 (ORCPT ); Fri, 3 Jul 2015 10:40:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,400,1432623600"; d="scan'208";a="722420422" From: Matthew Wilcox To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Viro Cc: Matthew Wilcox , willy@linux.intel.com Subject: [PATCH v2 5/6] block: Add support for DAX reads/writes to block devices Date: Fri, 3 Jul 2015 10:40:42 -0400 Message-Id: <1435934443-17090-6-git-send-email-matthew.r.wilcox@intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1435934443-17090-1-git-send-email-matthew.r.wilcox@intel.com> References: <1435934443-17090-1-git-send-email-matthew.r.wilcox@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2211 Lines: 67 If a block device supports the ->direct_access methods, bypass the normal DIO path and use DAX to go straight to memcpy() instead of allocating a DIO and a BIO. Includes support for the DIO_SKIP_DIO_COUNT flag in DAX, as is done in do_blockdev_direct_IO(). Signed-off-by: Matthew Wilcox --- fs/block_dev.c | 4 ++++ fs/dax.c | 6 ++++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 4fe10f9..0bb2993 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -152,6 +152,9 @@ blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset) struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; + if (IS_DAX(inode)) + return dax_do_io(iocb, inode, iter, offset, blkdev_get_block, + NULL, DIO_SKIP_DIO_COUNT); return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter, offset, blkdev_get_block, NULL, NULL, DIO_SKIP_DIO_COUNT); @@ -1170,6 +1173,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) bdev->bd_disk = disk; bdev->bd_queue = disk->queue; bdev->bd_contains = bdev; + bdev->bd_inode->i_flags = disk->fops->direct_access ? S_DAX : 0; if (!partno) { ret = -ENXIO; bdev->bd_part = disk_get_part(disk, partno); diff --git a/fs/dax.c b/fs/dax.c index eaa9e06..c3e21cc 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -209,7 +209,8 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, } /* Protects against truncate */ - inode_dio_begin(inode); + if (!(flags & DIO_SKIP_DIO_COUNT)) + inode_dio_begin(inode); retval = dax_io(inode, iter, pos, end, get_block, &bh); @@ -219,7 +220,8 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, if ((retval > 0) && end_io) end_io(iocb, pos, retval, bh.b_private); - inode_dio_end(inode); + if (!(flags & DIO_SKIP_DIO_COUNT)) + inode_dio_end(inode); out: return retval; } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/