From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail03.adl2.internode.on.net ([150.101.137.141]:19610 "EHLO ipmail03.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751127AbeEBGCL (ORCPT ); Wed, 2 May 2018 02:02:11 -0400 From: Dave Chinner To: linux-xfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, hch@lst.de, rdorr@microsoft.com Subject: [PATCH 2/3] iomap: iomap_dio_rw() handles all sync writes Date: Wed, 2 May 2018 15:38:06 +1000 Message-Id: <20180502053807.13846-3-david@fromorbit.com> In-Reply-To: <20180502053807.13846-1-david@fromorbit.com> References: <20180502053807.13846-1-david@fromorbit.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Dave Chinner Currently iomap_dio_rw() only handles (data)sync write completions for AIO. This means we can't optimised non-AIO IO to minimise device flushes as we can't tell the caller whether a flush is required or not. To solve this problem and enable further optimisations, make iomap_dio_rw responsible for data sync behaviour for all IO, not just AIO. In doing so, the sync operation is now accounted as part of the DIO IO by inode_dio_end(), hence post-IO data stability updates will no long race against operations that serialise via inode_dio_wait() such as truncate or hole punch. Signed-Off-By: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/iomap.c | 21 +++++++++++++++------ fs/xfs/xfs_file.c | 5 ----- 2 files changed, 15 insertions(+), 11 deletions(-) diff --git a/fs/iomap.c b/fs/iomap.c index afd163586aa0..b044d8ee2efd 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -685,6 +685,7 @@ EXPORT_SYMBOL_GPL(iomap_seek_data); * Private flags for iomap_dio, must not overlap with the public ones in * iomap.h: */ +#define IOMAP_DIO_NEED_SYNC (1 << 29) #define IOMAP_DIO_WRITE (1 << 30) #define IOMAP_DIO_DIRTY (1 << 31) @@ -759,6 +760,13 @@ static ssize_t iomap_dio_complete(struct iomap_dio *dio) dio_warn_stale_pagecache(iocb->ki_filp); } + /* + * If this is a DSYNC write, make sure we push it to stable storage now + * that we've written data. + */ + if (ret > 0 && (dio->flags & IOMAP_DIO_NEED_SYNC)) + ret = generic_write_sync(iocb, ret); + inode_dio_end(file_inode(iocb->ki_filp)); kfree(dio); @@ -769,13 +777,8 @@ static void iomap_dio_complete_work(struct work_struct *work) { struct iomap_dio *dio = container_of(work, struct iomap_dio, aio.work); struct kiocb *iocb = dio->iocb; - bool is_write = (dio->flags & IOMAP_DIO_WRITE); - ssize_t ret; - ret = iomap_dio_complete(dio); - if (is_write && ret > 0) - ret = generic_write_sync(iocb, ret); - iocb->ki_complete(iocb, ret, 0); + iocb->ki_complete(iocb, iomap_dio_complete(dio), 0); } /* @@ -961,6 +964,10 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length, return copied; } +/* + * iomap_dio_rw() always completes O_[D]SYNC writes regardless of whether the IO + * is being issued as AIO or not. + */ ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, iomap_dio_end_io_t end_io) @@ -1006,6 +1013,8 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, dio->flags |= IOMAP_DIO_DIRTY; } else { dio->flags |= IOMAP_DIO_WRITE; + if (iocb->ki_flags & IOCB_DSYNC) + dio->flags |= IOMAP_DIO_NEED_SYNC; flags |= IOMAP_WRITE; } diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 4cbd15d84bb8..64112a57b004 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -570,11 +570,6 @@ xfs_file_dio_aio_write( * complete fully or fail. */ ASSERT(ret < 0 || ret == count); - - if (ret > 0) { - /* Handle various SYNC-type writes */ - ret = generic_write_sync(iocb, ret); - } return ret; } -- 2.17.0