From patchwork Thu Apr 28 21:16:56 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 8974951 Return-Path: X-Original-To: patchwork-linux-block@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 9EEA39F1D3 for ; Thu, 28 Apr 2016 21:18:39 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6BEDE202A1 for ; Thu, 28 Apr 2016 21:18:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A9C2202AE for ; Thu, 28 Apr 2016 21:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753781AbcD1VSQ (ORCPT ); Thu, 28 Apr 2016 17:18:16 -0400 Received: from mga01.intel.com ([192.55.52.88]:27659 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752455AbcD1VRZ (ORCPT ); Thu, 28 Apr 2016 17:17:25 -0400 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP; 28 Apr 2016 14:17:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,548,1455004800"; d="scan'208";a="942415549" Received: from omniknight.lm.intel.com ([10.232.112.171]) by orsmga001.jf.intel.com with ESMTP; 28 Apr 2016 14:17:23 -0700 From: Vishal Verma To: linux-nvdimm@lists.01.org Cc: Vishal Verma , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Matthew Wilcox , Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Al Viro , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer Subject: [PATCH v4 5/7] fs: prioritize and separate direct_io from dax_io Date: Thu, 28 Apr 2016 15:16:56 -0600 Message-Id: <1461878218-3844-6-git-send-email-vishal.l.verma@intel.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1461878218-3844-1-git-send-email-vishal.l.verma@intel.com> References: <1461878218-3844-1-git-send-email-vishal.l.verma@intel.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Spam-Status: No, score=-7.9 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 All IO in a dax filesystem used to go through dax_do_io, which cannot handle media errors, and thus cannot provide a recovery path that can send a write through the driver to clear errors. Add a new iocb flag for DAX, and set it only for DAX mounts. In the IO path for DAX filesystems, use the same direct_IO path for both DAX and direct_io iocbs, but use the flags to identify when we are in O_DIRECT mode vs non O_DIRECT with DAX, and for O_DIRECT, use the conventional direct_IO path instead of DAX. This allows us a recovery path in the form of opening the file with O_DIRECT and writing to it with the usual O_DIRECT semantics (sector alignment restrictions). Cc: Matthew Wilcox Cc: Dan Williams Cc: Ross Zwisler Cc: Jeff Moyer Cc: Christoph Hellwig Cc: Dave Chinner Cc: Jan Kara Cc: Jens Axboe Cc: Al Viro Signed-off-by: Vishal Verma --- drivers/block/loop.c | 2 +- fs/block_dev.c | 17 +++++++++++++---- fs/ext2/inode.c | 16 ++++++++++++---- fs/ext4/file.c | 2 +- fs/ext4/inode.c | 19 +++++++++++++------ fs/xfs/xfs_aops.c | 20 +++++++++++++------- fs/xfs/xfs_file.c | 4 ++-- include/linux/fs.h | 15 ++++++++++++--- mm/filemap.c | 4 ++-- 9 files changed, 69 insertions(+), 30 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 80cf8ad..c0a24c3 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -568,7 +568,7 @@ struct switch_request { static inline void loop_update_dio(struct loop_device *lo) { - __loop_update_dio(lo, io_is_direct(lo->lo_backing_file) | + __loop_update_dio(lo, (lo->lo_backing_file->f_flags & O_DIRECT) | lo->use_dio); } diff --git a/fs/block_dev.c b/fs/block_dev.c index 79defba..97a1f5f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -167,12 +167,21 @@ blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset) struct file *file = iocb->ki_filp; struct inode *inode = bdev_file_inode(file); - if (IS_DAX(inode)) + if (iocb_is_direct(iocb)) + return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter, + offset, blkdev_get_block, NULL, + NULL, DIO_SKIP_DIO_COUNT); + else if (iocb_is_dax(iocb)) 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); + else { + /* + * If we're in the direct_IO path, either the IOCB_DIRECT or + * IOCB_DAX flags must be set. + */ + WARN_ONCE(1, "Kernel Bug with iocb flags\n"); + return -ENXIO; + } } int __sync_blockdev(struct block_device *bdev, int wait) diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 35f2b0bf..45f2b51 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -861,12 +861,20 @@ ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset) size_t count = iov_iter_count(iter); ssize_t ret; - if (IS_DAX(inode)) - ret = dax_do_io(iocb, inode, iter, offset, ext2_get_block, NULL, - DIO_LOCKING); - else + if (iocb_is_direct(iocb)) ret = blockdev_direct_IO(iocb, inode, iter, offset, ext2_get_block); + else if (iocb_is_dax(iocb)) + ret = dax_do_io(iocb, inode, iter, offset, ext2_get_block, NULL, + DIO_LOCKING); + else { + /* + * If we're in the direct_IO path, either the IOCB_DIRECT or + * IOCB_DAX flags must be set. + */ + WARN_ONCE(1, "Kernel Bug with iocb flags\n"); + return -ENXIO; + } if (ret < 0 && iov_iter_rw(iter) == WRITE) ext2_write_failed(mapping, offset + count); return ret; diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 2e9aa49..165a0b8 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -94,7 +94,7 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) struct file *file = iocb->ki_filp; struct inode *inode = file_inode(iocb->ki_filp); struct blk_plug plug; - int o_direct = iocb->ki_flags & IOCB_DIRECT; + int o_direct = iocb->ki_flags & (IOCB_DIRECT | IOCB_DAX); int unaligned_aio = 0; int overwrite = 0; ssize_t ret; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 6d5d5c1..0b6d77a 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3410,15 +3410,22 @@ static ssize_t ext4_direct_IO_write(struct kiocb *iocb, struct iov_iter *iter, #ifdef CONFIG_EXT4_FS_ENCRYPTION BUG_ON(ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)); #endif - if (IS_DAX(inode)) { - ret = dax_do_io(iocb, inode, iter, offset, get_block_func, - ext4_end_io_dio, dio_flags); - } else + if (iocb_is_direct(iocb)) ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter, offset, get_block_func, ext4_end_io_dio, NULL, dio_flags); - + else if (iocb_is_dax(iocb)) + ret = dax_do_io(iocb, inode, iter, offset, get_block_func, + ext4_end_io_dio, dio_flags); + else { + /* + * If we're in the direct_IO path, either the IOCB_DIRECT or + * IOCB_DAX flags must be set. + */ + WARN_ONCE(1, "Kernel Bug with iocb flags\n"); + return -ENXIO; + } if (ret > 0 && !overwrite && ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN)) { int err; @@ -3503,7 +3510,7 @@ static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter, else unlocked = 1; } - if (IS_DAX(inode)) { + if (iocb_is_dax(iocb)) { ret = dax_do_io(iocb, inode, iter, offset, ext4_dio_get_block, NULL, unlocked ? 0 : DIO_LOCKING); } else { diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index e49b240..8134e99 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1412,21 +1412,27 @@ xfs_vm_direct_IO( struct inode *inode = iocb->ki_filp->f_mapping->host; dio_iodone_t *endio = NULL; int flags = 0; - struct block_device *bdev; + struct block_device *bdev = xfs_find_bdev_for_inode(inode); if (iov_iter_rw(iter) == WRITE) { endio = xfs_end_io_direct_write; flags = DIO_ASYNC_EXTEND; } - if (IS_DAX(inode)) { + if (iocb_is_direct(iocb)) + return __blockdev_direct_IO(iocb, inode, bdev, iter, offset, + xfs_get_blocks_direct, endio, NULL, flags); + else if (iocb_is_dax(iocb)) return dax_do_io(iocb, inode, iter, offset, - xfs_get_blocks_direct, endio, 0); + xfs_get_blocks_direct, endio, 0); + else { + /* + * If we're in the direct_IO path, either the IOCB_DIRECT or + * IOCB_DAX flags must be set. + */ + WARN_ONCE(1, "Kernel Bug with iocb flags\n"); + return -ENXIO; } - - bdev = xfs_find_bdev_for_inode(inode); - return __blockdev_direct_IO(iocb, inode, bdev, iter, offset, - xfs_get_blocks_direct, endio, NULL, flags); } /* diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index c2946f4..3d5d3c2 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -300,7 +300,7 @@ xfs_file_read_iter( XFS_STATS_INC(mp, xs_read_calls); - if (unlikely(iocb->ki_flags & IOCB_DIRECT)) + if (unlikely(iocb->ki_flags & (IOCB_DIRECT | IOCB_DAX))) ioflags |= XFS_IO_ISDIRECT; if (file->f_mode & FMODE_NOCMTIME) ioflags |= XFS_IO_INVIS; @@ -898,7 +898,7 @@ xfs_file_write_iter( if (XFS_FORCED_SHUTDOWN(ip->i_mount)) return -EIO; - if ((iocb->ki_flags & IOCB_DIRECT) || IS_DAX(inode)) + if ((iocb->ki_flags & (IOCB_DIRECT | IOCB_DAX))) ret = xfs_file_dio_aio_write(iocb, from); else ret = xfs_file_buffered_aio_write(iocb, from); diff --git a/include/linux/fs.h b/include/linux/fs.h index 9f28130..adca1d8 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -322,6 +322,7 @@ struct writeback_control; #define IOCB_APPEND (1 << 1) #define IOCB_DIRECT (1 << 2) #define IOCB_HIPRI (1 << 3) +#define IOCB_DAX (1 << 4) struct kiocb { struct file *ki_filp; @@ -2930,9 +2931,15 @@ extern int generic_show_options(struct seq_file *m, struct dentry *root); extern void save_mount_options(struct super_block *sb, char *options); extern void replace_mount_options(struct super_block *sb, char *options); -static inline bool io_is_direct(struct file *filp) +static inline bool iocb_is_dax(struct kiocb *iocb) { - return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host); + return IS_DAX(file_inode(iocb->ki_filp)) && + (iocb->ki_flags & IOCB_DAX); +} + +static inline bool iocb_is_direct(struct kiocb *iocb) +{ + return iocb->ki_flags & IOCB_DIRECT; } static inline int iocb_flags(struct file *file) @@ -2940,8 +2947,10 @@ static inline int iocb_flags(struct file *file) int res = 0; if (file->f_flags & O_APPEND) res |= IOCB_APPEND; - if (io_is_direct(file)) + if (file->f_flags & O_DIRECT) res |= IOCB_DIRECT; + if (IS_DAX(file_inode(file))) + res |= IOCB_DAX; return res; } diff --git a/mm/filemap.c b/mm/filemap.c index 3effd5c..b959acf 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1849,7 +1849,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) if (!count) goto out; /* skip atime */ - if (iocb->ki_flags & IOCB_DIRECT) { + if (iocb->ki_flags & (IOCB_DIRECT | IOCB_DAX)) { struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; loff_t size; @@ -2719,7 +2719,7 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) if (err) goto out; - if (iocb->ki_flags & IOCB_DIRECT) { + if (iocb->ki_flags & (IOCB_DIRECT | IOCB_DAX)) { loff_t pos, endbyte; written = generic_file_direct_write(iocb, from, iocb->ki_pos);