From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:56502 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751723AbeCERo4 (ORCPT ); Mon, 5 Mar 2018 12:44:56 -0500 Date: Mon, 5 Mar 2018 17:44:55 +0000 From: "Luis R. Rodriguez" Subject: Re: [PATCH] xfs: fix transaction allocation deadlock in IO path Message-ID: <20180305174455.GB14201@wotan.suse.de> References: <20180305041120.4224-1-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180305041120.4224-1-david@fromorbit.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Dave Chinner Cc: linux-xfs@vger.kernel.org On Mon, Mar 05, 2018 at 03:11:20PM +1100, Dave Chinner wrote: > From: Dave Chinner > > xfs_trans_alloc() does GFP_KERNEL allocation, and we can call it > while holding pages locked for writeback in the ->writepages path. > The memory allocation is allowed to wait on pages under writeback, > and so can wait on pages that are held locked in writeback by the > caller. > > This affects both pre-IO submission and post-IO submission paths. > Hence xfs_setsize_trans_alloc(), xfs_reflink_end_cow(), > xfs_iomap_write_unwritten() and xfs_reflink_cancel_cow_range(). > xfs_iomap_write_unwritten() already does the right thing, but the > others don't. Fix them. > > Signed-Off-By: Dave Chinner I believe these are two separate regressions though, introduced on separate kernels Can we treat them as such and use respective Fixes tag for them? > --- > fs/xfs/xfs_aops.c | 3 ++- > fs/xfs/xfs_reflink.c | 4 ++-- > 2 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c > index 9c6a830da0ee..a0afb6411417 100644 > --- a/fs/xfs/xfs_aops.c > +++ b/fs/xfs/xfs_aops.c > @@ -209,7 +209,8 @@ xfs_setfilesize_trans_alloc( > struct xfs_trans *tp; > int error; > > - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp); > + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, > + XFS_TRANS_NOFS, &tp); > if (error) > return error; > Fixes: 253f4911f297b ("xfs: better xfs_trans_alloc interface") Introduced on v4.7 > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index 270246943a06..8c16177b33d4 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -668,7 +668,7 @@ xfs_reflink_cancel_cow_range( > > /* Start a rolling transaction to remove the mappings */ > error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, > - 0, 0, 0, &tp); > + 0, 0, XFS_TRANS_NOFS, &tp); > if (error) > goto out; > > @@ -741,7 +741,7 @@ xfs_reflink_end_cow( > (unsigned int)(end_fsb - offset_fsb), > XFS_DATA_FORK); > error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, > - resblks, 0, XFS_TRANS_RESERVE, &tp); > + resblks, 0, XFS_TRANS_RESERVE | XFS_TRANS_NOFS, &tp); > if (error) > goto out; For both of the above: Fixes: 43caeb187deb9 ("xfs: move mappings from cow fork to data fork after copy-write)" Introduced on v4.9. Luis