Return-Path: Received: from mail-ig0-f196.google.com ([209.85.213.196]:36726 "EHLO mail-ig0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753697AbcD0RmE (ORCPT ); Wed, 27 Apr 2016 13:42:04 -0400 Received: by mail-ig0-f196.google.com with SMTP id c3so7264667igl.3 for ; Wed, 27 Apr 2016 10:42:04 -0700 (PDT) Subject: Re: [PATCH 1.1/2] xfs: abstract PF_FSTRANS to PF_MEMALLOC_NOFS Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Content-Type: multipart/signed; boundary="Apple-Mail=_E2A13889-F5F8-484A-9C14-046AD6B7906F"; protocol="application/pgp-signature"; micalg=pgp-sha256 From: Andreas Dilger In-Reply-To: <1461758075-21815-1-git-send-email-mhocko@kernel.org> Date: Wed, 27 Apr 2016 11:41:51 -0600 Cc: Linux MM , linux-fsdevel , Andrew Morton , Dave Chinner , "Theodore Ts'o" , Chris Mason , Jan Kara , ceph-devel@vger.kernel.org, cluster-devel , Linux NFS Mailing List , logfs@logfs.org, XFS Developers , linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mtd@lists.infradead.org, reiserfs-devel@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, linux-f2fs-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, LKML , Michal Hocko Message-Id: <04798BA8-2157-4611-B4EA-B8BCBA88AEC3@dilger.ca> References: <1461671772-1269-2-git-send-email-mhocko@kernel.org> <1461758075-21815-1-git-send-email-mhocko@kernel.org> To: Michal Hocko Sender: linux-nfs-owner@vger.kernel.org List-ID: --Apple-Mail=_E2A13889-F5F8-484A-9C14-046AD6B7906F Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii On Apr 27, 2016, at 5:54 AM, Michal Hocko wrote: >=20 > From: Michal Hocko >=20 > xfs has defined PF_FSTRANS to declare a scope GFP_NOFS semantic quite > some time ago. We would like to make this concept more generic and use > it for other filesystems as well. Let's start by giving the flag a > more genric name PF_MEMALLOC_NOFS which is in line with an exiting > PF_MEMALLOC_NOIO already used for the same purpose for GFP_NOIO > contexts. Replace all PF_FSTRANS usage from the xfs code in the first > step before we introduce a full API for it as xfs uses the flag = directly > anyway. >=20 > This patch doesn't introduce any functional change. >=20 > Signed-off-by: Michal Hocko > --- > Hi, > as suggested by Dave, I have split up [1] into two parts. The first = one > addes a new PF flag which is just an alias to the existing PF_FSTRANS > and does all the renaming and the second one to introduce the generic > API which only changes the bare minimum in the xfs proper. >=20 > fs/xfs/kmem.c | 4 ++-- > fs/xfs/kmem.h | 2 +- > fs/xfs/libxfs/xfs_btree.c | 2 +- > fs/xfs/xfs_aops.c | 6 +++--- > fs/xfs/xfs_trans.c | 12 ++++++------ > include/linux/sched.h | 2 ++ > 6 files changed, 15 insertions(+), 13 deletions(-) >=20 > diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c > index 686ba6fb20dd..73f6ab59c664 100644 > --- a/fs/xfs/kmem.c > +++ b/fs/xfs/kmem.c > @@ -80,13 +80,13 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t = flags) > * context via PF_MEMALLOC_NOIO to prevent memory reclaim = re-entering > * the filesystem here and potentially deadlocking. > */ > - if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS)) > + if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) > noio_flag =3D memalloc_noio_save(); >=20 > lflags =3D kmem_flags_convert(flags); > ptr =3D __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, = PAGE_KERNEL); >=20 > - if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS)) > + if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) > memalloc_noio_restore(noio_flag); Not really the fault of this patch, but it brings this nasty bit of code = into the light. Is all of this machinery still needed given that __vmalloc() = can accept GFP flags? If yes, wouldn't it be better to fix __vmalloc() to = honor the GFP flags instead of working around it in the filesystem code? Cheers, Andreas > return ptr; > diff --git a/fs/xfs/kmem.h b/fs/xfs/kmem.h > index d1c66e465ca5..0d83f332e5c2 100644 > --- a/fs/xfs/kmem.h > +++ b/fs/xfs/kmem.h > @@ -50,7 +50,7 @@ kmem_flags_convert(xfs_km_flags_t flags) > lflags =3D GFP_ATOMIC | __GFP_NOWARN; > } else { > lflags =3D GFP_KERNEL | __GFP_NOWARN; > - if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS)) > + if ((current->flags & PF_MEMALLOC_NOFS) || (flags & = KM_NOFS)) > lflags &=3D ~__GFP_FS; > } >=20 > diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c > index a0eb18ce3ad3..326566f4a131 100644 > --- a/fs/xfs/libxfs/xfs_btree.c > +++ b/fs/xfs/libxfs/xfs_btree.c > @@ -2540,7 +2540,7 @@ xfs_btree_split_worker( > struct xfs_btree_split_args *args =3D container_of(work, > struct = xfs_btree_split_args, work); > unsigned long pflags; > - unsigned long new_pflags =3D PF_FSTRANS; > + unsigned long new_pflags =3D PF_MEMALLOC_NOFS; >=20 > /* > * we are in a transaction context here, but may also be doing = work > diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c > index d12dfcfd0cc8..6d816ff0b763 100644 > --- a/fs/xfs/xfs_aops.c > +++ b/fs/xfs/xfs_aops.c > @@ -124,7 +124,7 @@ xfs_setfilesize_trans_alloc( > * We hand off the transaction to the completion thread now, so > * clear the flag here. > */ > - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); > + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); > return 0; > } >=20 > @@ -169,7 +169,7 @@ xfs_setfilesize_ioend( > * thus we need to mark ourselves as being in a transaction = manually. > * Similarly for freeze protection. > */ > - current_set_flags_nested(&tp->t_pflags, PF_FSTRANS); > + current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); > __sb_writers_acquired(VFS_I(ip)->i_sb, SB_FREEZE_FS); >=20 > /* we abort the update if there was an IO error */ > @@ -979,7 +979,7 @@ xfs_vm_writepage( > * Given that we do not allow direct reclaim to call us, we = should > * never be called while in a filesystem transaction. > */ > - if (WARN_ON_ONCE(current->flags & PF_FSTRANS)) > + if (WARN_ON_ONCE(current->flags & PF_MEMALLOC_NOFS)) > goto redirty; >=20 > /* Is this page beyond the end of the file? */ > diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c > index 748b16aff45a..1d247366c733 100644 > --- a/fs/xfs/xfs_trans.c > +++ b/fs/xfs/xfs_trans.c > @@ -176,7 +176,7 @@ xfs_trans_reserve( > bool rsvd =3D (tp->t_flags & XFS_TRANS_RESERVE) !=3D = 0; >=20 > /* Mark this thread as being in a transaction */ > - current_set_flags_nested(&tp->t_pflags, PF_FSTRANS); > + current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); >=20 > /* > * Attempt to reserve the needed disk blocks by decrementing > @@ -186,7 +186,7 @@ xfs_trans_reserve( > if (blocks > 0) { > error =3D xfs_mod_fdblocks(tp->t_mountp, = -((int64_t)blocks), rsvd); > if (error !=3D 0) { > - current_restore_flags_nested(&tp->t_pflags, = PF_FSTRANS); > + current_restore_flags_nested(&tp->t_pflags, = PF_MEMALLOC_NOFS); > return -ENOSPC; > } > tp->t_blk_res +=3D blocks; > @@ -263,7 +263,7 @@ xfs_trans_reserve( > tp->t_blk_res =3D 0; > } >=20 > - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); > + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); >=20 > return error; > } > @@ -921,7 +921,7 @@ __xfs_trans_commit( >=20 > xfs_log_commit_cil(mp, tp, &commit_lsn, regrant); >=20 > - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); > + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); > xfs_trans_free(tp); >=20 > /* > @@ -951,7 +951,7 @@ __xfs_trans_commit( > if (commit_lsn =3D=3D -1 && !error) > error =3D -EIO; > } > - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); > + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); > xfs_trans_free_items(tp, NULLCOMMITLSN, !!error); > xfs_trans_free(tp); >=20 > @@ -1005,7 +1005,7 @@ xfs_trans_cancel( > xfs_log_done(mp, tp->t_ticket, NULL, false); >=20 > /* mark this thread as no longer being in a transaction */ > - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); > + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); >=20 > xfs_trans_free_items(tp, NULLCOMMITLSN, dirty); > xfs_trans_free(tp); > diff --git a/include/linux/sched.h b/include/linux/sched.h > index acfc32b30704..820db8f98bfc 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -2115,6 +2115,8 @@ extern void thread_group_cputime_adjusted(struct = task_struct *p, cputime_t *ut, > #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not = count it as freezable */ > #define PF_SUSPEND_TASK 0x80000000 /* this thread called = freeze_processes and should not be frozen */ >=20 > +#define PF_MEMALLOC_NOFS PF_FSTRANS /* Transition to a more generic = GFP_NOFS scope semantic */ > + > /* > * Only the _current_ task can read/write to tsk->flags, but other > * tasks can access tsk->flags in readonly mode for example > -- > 2.8.0.rc3 >=20 > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" = in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Cheers, Andreas --Apple-Mail=_E2A13889-F5F8-484A-9C14-046AD6B7906F Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Comment: GPGTools - http://gpgtools.org iQIVAwUBVyD54HKl2rkXzB/gAQhFgA//ZYuehVpoM5drnP3bbKWtQjn+P6DN/JN+ Tm6ZVTirAPubH6MoXJ2+c7UHpnxzIRKlauzLQkZih1i3oYUyC58bNJuSeJNmffsY QVqB/INiLvJhfSwzzUzJEAZBrrrMp5laltsy4fgc13GqRoeT4wY3IoTb4ZofuC9G ij6BiTMALIp6IkhPNk/9Ru5jBqWbcVTMHngMfeYrWRuzKOM7QO58ceqCYM4xsz7n QuH/685BricBeQYPxQXaaAM0Gh6LAUd4ctzWFBpJavT+oaJoG7/JLSTUoLU/2W0b pGJHCCWpY59eUz1AT13PGTYcCxo6+ta+PRtWX8qEuME5vrsCkfYgUHjkislp3avM dahSdlxRLo5Ji4kxUiKS9RATKRfh1G7ucKsUC+PIeaXjfQEGXaihjFFHj0ioHVtl vqVlOmxSCSXhwHbvLiwehrb2njBhtfTplbQ1YL370/c00tezhDbDMrp4q1GmuCGJ 1ewQTTHhixNPogyV5ameP/4oq8CMCztnmGw65/54BCcORcOkgE4Vprwwvi+AOJP4 DG5SdP+Sj4DdcOHI2MtDjvna9vGLbiINSsu76YPgltbvnQMqp+CUyK9qBoBsXNUi Aco5N8PaQWzKloGPDOeVzHdMBononKFf+4wtbaQ0kEUkX0bXdvkSJqxlDsK/6wnE 05SCP6c8sd4= =dU5k -----END PGP SIGNATURE----- --Apple-Mail=_E2A13889-F5F8-484A-9C14-046AD6B7906F--