From: Jan Kara Subject: [PATCH 18/19] xfs: support for synchronous DAX faults Date: Wed, 11 Oct 2017 22:06:02 +0200 Message-ID: <20171011200603.27442-19-jack@suse.cz> References: <20171011200603.27442-1-jack@suse.cz> Cc: , , Christoph Hellwig , Dan Williams , Ross Zwisler , Ted Tso , "Darrick J. Wong" , Christoph Hellwig , Jan Kara To: Return-path: Received: from mx2.suse.de ([195.135.220.15]:58290 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752786AbdJKUGV (ORCPT ); Wed, 11 Oct 2017 16:06:21 -0400 In-Reply-To: <20171011200603.27442-1-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Christoph Hellwig Return IOMAP_F_NEEDDSYNC from xfs_file_iomap_begin() for a synchronous write fault when inode is pinned, and has dirty fields other than the timestamps. In xfs_filemap_huge_fault() we then detect this case and call dax_finish_sync_fault() to make sure all metadata is committed, and to insert the page table entry. Note that this will also dirty corresponding radix tree entry which is what we want - fsync(2) will still provide data integrity guarantees for applications not using userspace flushing. And applications using userspace flushing can avoid calling fsync(2) and thus avoid the performance overhead. Signed-off-by: Christoph Hellwig Signed-off-by: Jan Kara --- fs/xfs/xfs_file.c | 6 +++++- fs/xfs/xfs_iomap.c | 5 +++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 7c6b8def6eed..c45f24ffab22 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1040,7 +1040,11 @@ __xfs_filemap_fault( xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); if (IS_DAX(inode)) { - ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops); + pfn_t pfn; + + ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops); + if (ret & VM_FAULT_NEEDDSYNC) + ret = dax_finish_sync_fault(vmf, pe_size, pfn); } else { if (write_fault) ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops); diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index f179bdf1644d..b43be199fbdf 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -33,6 +33,7 @@ #include "xfs_error.h" #include "xfs_trans.h" #include "xfs_trans_space.h" +#include "xfs_inode_item.h" #include "xfs_iomap.h" #include "xfs_trace.h" #include "xfs_icache.h" @@ -1086,6 +1087,10 @@ xfs_file_iomap_begin( trace_xfs_iomap_found(ip, offset, length, 0, &imap); } + if ((flags & IOMAP_WRITE) && xfs_ipincount(ip) && + (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) + iomap->flags |= IOMAP_F_DIRTY; + xfs_bmbt_to_iomap(ip, iomap, &imap); if (shared) -- 2.12.3