From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2130.oracle.com (userp2130.oracle.com [156.151.31.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 16DDD210E435C for ; Fri, 10 Aug 2018 09:02:50 -0700 (PDT) Date: Fri, 10 Aug 2018 09:02:43 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH v2 2/2] [PATCH] xfs: Close race between direct IO and xfs_break_layouts() Message-ID: <20180810160243.GF4203@magnolia> References: <153374942137.42241.10539674028265137668.stgit@djiang5-desk3.ch.intel.com> <20180810154809.GD15083@magnolia> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Dave Jiang Cc: lczerner@redhat.com, jack@suse.cz, linux-nvdimm@lists.01.org, david@fromorbit.com, linux-xfs@vger.kernel.org, zwisler@kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, linux-ext4@vger.kernel.org, hch@lst.de List-ID: On Fri, Aug 10, 2018 at 08:54:00AM -0700, Dave Jiang wrote: > > > On 08/10/2018 08:48 AM, Darrick J. Wong wrote: > > On Wed, Aug 08, 2018 at 10:31:40AM -0700, Dave Jiang wrote: > >> This patch is the duplicate of ross's fix for ext4 for xfs. > >> > >> If the refcount of a page is lowered between the time that it is returned > >> by dax_busy_page() and when the refcount is again checked in > >> xfs_break_layouts() => ___wait_var_event(), the waiting function > >> xfs_wait_dax_page() will never be called. This means that > >> xfs_break_layouts() will still have 'retry' set to false, so we'll stop > >> looping and never check the refcount of other pages in this inode. > >> > >> Instead, always continue looping as long as dax_layout_busy_page() gives us > >> a page which it found with an elevated refcount. > >> > >> Signed-off-by: Dave Jiang > >> Reviewed-by: Jan Kara > >> --- > >> > >> Sorry resend, forgot to add Jan's reviewed-by. > >> > >> v2: > >> - Rename parameter from did_unlock to retry (Jan) > >> > >> fs/xfs/xfs_file.c | 9 ++++----- > >> 1 file changed, 4 insertions(+), 5 deletions(-) > >> > >> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > >> index a3e7767a5715..cd6f0d8c4922 100644 > >> --- a/fs/xfs/xfs_file.c > >> +++ b/fs/xfs/xfs_file.c > >> @@ -721,12 +721,10 @@ xfs_file_write_iter( > >> > >> static void > >> xfs_wait_dax_page( > >> - struct inode *inode, > >> - bool *did_unlock) > >> + struct inode *inode) > >> { > >> struct xfs_inode *ip = XFS_I(inode); > >> > >> - *did_unlock = true; > >> xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); > >> schedule(); > >> xfs_ilock(ip, XFS_MMAPLOCK_EXCL); > >> @@ -736,7 +734,7 @@ static int > >> xfs_break_dax_layouts( > >> struct inode *inode, > >> uint iolock, > >> - bool *did_unlock) > >> + bool *retry) > > > > Uhhh, this hunk doesn't apply. xfs_break_dax_layouts doesn't have an > > iolock parameter anymore; was this not generated off of xfs for-next? > > Sorry. It was generated against 4.18-rc8. I'll respin patch against xfs > for-next. I think it's just a matter of taking the old patch and changing "did_unlock" to "retry", right? If so, I'll just change that and be done with this one. :) --D > > > > --D > > > >> { > >> struct page *page; > >> > >> @@ -746,9 +744,10 @@ xfs_break_dax_layouts( > >> if (!page) > >> return 0; > >> > >> + *retry = true; > >> return ___wait_var_event(&page->_refcount, > >> atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE, > >> - 0, 0, xfs_wait_dax_page(inode, did_unlock)); > >> + 0, 0, xfs_wait_dax_page(inode)); > >> } > >> > >> int > >> > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > >> the body of a message to majordomo@vger.kernel.org > >> More majordomo info at http://vger.kernel.org/majordomo-info.html _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm