* [PATCH 1/3] xfs: remove dax EXPERIMENTAL warning
2021-09-15 17:22 [PATCH 0/3 RFC] Remove DAX experimental warnings Eric Sandeen
@ 2021-09-15 17:22 ` Eric Sandeen
2021-09-15 18:54 ` Dan Williams
2021-09-15 17:22 ` [PATCH 2/3] ext4: " Eric Sandeen
` (2 subsequent siblings)
3 siblings, 1 reply; 14+ messages in thread
From: Eric Sandeen @ 2021-09-15 17:22 UTC (permalink / raw)
To: linux-xfs, linux-ext4, linux-fsdevel; +Cc: dan.j.williams
As there seems to be no significant outstanding concern about
dax on xfs at this point, remove the scary EXPERIMENTAL
warning when in use.
(dax+reflink is still unimplemented, but that can be considered
a future feature, and doesn't require a warning for the
non-reflink usecase.)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
fs/xfs/xfs_super.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index c4e0cd1..0c71dbb 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1594,9 +1594,6 @@ struct proc_xfs_info {
if (xfs_has_dax_always(mp)) {
bool rtdev_is_dax = false, datadev_is_dax;
- xfs_warn(mp,
- "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
-
datadev_is_dax = xfs_buftarg_is_dax(sb, mp->m_ddev_targp);
if (mp->m_rtdev_targp)
rtdev_is_dax = xfs_buftarg_is_dax(sb,
--
1.8.3.1
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH 1/3] xfs: remove dax EXPERIMENTAL warning
2021-09-15 17:22 ` [PATCH 1/3] xfs: remove dax EXPERIMENTAL warning Eric Sandeen
@ 2021-09-15 18:54 ` Dan Williams
0 siblings, 0 replies; 14+ messages in thread
From: Dan Williams @ 2021-09-15 18:54 UTC (permalink / raw)
To: Eric Sandeen; +Cc: linux-xfs, linux-ext4, linux-fsdevel
On Wed, Sep 15, 2021 at 10:23 AM Eric Sandeen <sandeen@redhat.com> wrote:
>
> As there seems to be no significant outstanding concern about
> dax on xfs at this point, remove the scary EXPERIMENTAL
> warning when in use.
>
> (dax+reflink is still unimplemented, but that can be considered
> a future feature, and doesn't require a warning for the
> non-reflink usecase.)
The original concern was that dax-reflink could not be implemented
without ABI regressions. As far as I can see that concern has been put
to rest by the proposed patches. Am I wrong? So, if we're committed to
not breaking past promises I think this change can be made
out-of-order from when the reflink support patches land.
Acked-by: Dan Williams <dan.j.williams@intel.com>
...but I'm also fine with waiting for the final reflink merge.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH 2/3] ext4: remove dax EXPERIMENTAL warning
2021-09-15 17:22 [PATCH 0/3 RFC] Remove DAX experimental warnings Eric Sandeen
2021-09-15 17:22 ` [PATCH 1/3] xfs: remove dax EXPERIMENTAL warning Eric Sandeen
@ 2021-09-15 17:22 ` Eric Sandeen
2021-09-17 9:47 ` Jan Kara
2021-09-15 17:22 ` [PATCH 3/3] ext2: " Eric Sandeen
2021-09-15 18:35 ` [PATCH 0/3 RFC] Remove DAX experimental warnings Dan Williams
3 siblings, 1 reply; 14+ messages in thread
From: Eric Sandeen @ 2021-09-15 17:22 UTC (permalink / raw)
To: linux-xfs, linux-ext4, linux-fsdevel; +Cc: dan.j.williams
As there seems to be no significant outstanding concern about
dax on ext4 at this point, remove the scary EXPERIMENTAL
warning when in use.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
fs/ext4/super.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 0775950..82948d6 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2346,8 +2346,6 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
"both data=journal and dax");
return -1;
}
- ext4_msg(sb, KERN_WARNING,
- "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
break;
--
1.8.3.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH 2/3] ext4: remove dax EXPERIMENTAL warning
2021-09-15 17:22 ` [PATCH 2/3] ext4: " Eric Sandeen
@ 2021-09-17 9:47 ` Jan Kara
0 siblings, 0 replies; 14+ messages in thread
From: Jan Kara @ 2021-09-17 9:47 UTC (permalink / raw)
To: Eric Sandeen; +Cc: linux-xfs, linux-ext4, linux-fsdevel, dan.j.williams
On Wed 15-09-21 12:22:40, Eric Sandeen wrote:
> As there seems to be no significant outstanding concern about
> dax on ext4 at this point, remove the scary EXPERIMENTAL
> warning when in use.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
I agree. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> fs/ext4/super.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 0775950..82948d6 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -2346,8 +2346,6 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
> "both data=journal and dax");
> return -1;
> }
> - ext4_msg(sb, KERN_WARNING,
> - "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
> sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
> sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
> break;
> --
> 1.8.3.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH 3/3] ext2: remove dax EXPERIMENTAL warning
2021-09-15 17:22 [PATCH 0/3 RFC] Remove DAX experimental warnings Eric Sandeen
2021-09-15 17:22 ` [PATCH 1/3] xfs: remove dax EXPERIMENTAL warning Eric Sandeen
2021-09-15 17:22 ` [PATCH 2/3] ext4: " Eric Sandeen
@ 2021-09-15 17:22 ` Eric Sandeen
2021-09-17 9:47 ` Jan Kara
2021-09-15 18:35 ` [PATCH 0/3 RFC] Remove DAX experimental warnings Dan Williams
3 siblings, 1 reply; 14+ messages in thread
From: Eric Sandeen @ 2021-09-15 17:22 UTC (permalink / raw)
To: linux-xfs, linux-ext4, linux-fsdevel; +Cc: dan.j.williams
As there seems to be no significant outstanding concern about
dax on ext2 at this point, remove the scary EXPERIMENTAL
warning when in use.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
fs/ext2/super.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index d8d580b..1915733 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -587,8 +587,6 @@ static int parse_options(char *options, struct super_block *sb,
fallthrough;
case Opt_dax:
#ifdef CONFIG_FS_DAX
- ext2_msg(sb, KERN_WARNING,
- "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
set_opt(opts->s_mount_opt, DAX);
#else
ext2_msg(sb, KERN_INFO, "dax option not supported");
--
1.8.3.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH 3/3] ext2: remove dax EXPERIMENTAL warning
2021-09-15 17:22 ` [PATCH 3/3] ext2: " Eric Sandeen
@ 2021-09-17 9:47 ` Jan Kara
2021-09-17 12:59 ` Christoph Hellwig
0 siblings, 1 reply; 14+ messages in thread
From: Jan Kara @ 2021-09-17 9:47 UTC (permalink / raw)
To: Eric Sandeen; +Cc: linux-xfs, linux-ext4, linux-fsdevel, dan.j.williams
On Wed 15-09-21 12:22:41, Eric Sandeen wrote:
> As there seems to be no significant outstanding concern about
> dax on ext2 at this point, remove the scary EXPERIMENTAL
> warning when in use.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Agreed. Do you want my ack or should I just merge this patch?
Honza
> ---
> fs/ext2/super.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/fs/ext2/super.c b/fs/ext2/super.c
> index d8d580b..1915733 100644
> --- a/fs/ext2/super.c
> +++ b/fs/ext2/super.c
> @@ -587,8 +587,6 @@ static int parse_options(char *options, struct super_block *sb,
> fallthrough;
> case Opt_dax:
> #ifdef CONFIG_FS_DAX
> - ext2_msg(sb, KERN_WARNING,
> - "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
> set_opt(opts->s_mount_opt, DAX);
> #else
> ext2_msg(sb, KERN_INFO, "dax option not supported");
> --
> 1.8.3.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 3/3] ext2: remove dax EXPERIMENTAL warning
2021-09-17 9:47 ` Jan Kara
@ 2021-09-17 12:59 ` Christoph Hellwig
2021-09-17 14:09 ` Eric Sandeen
2021-09-22 2:36 ` Darrick J. Wong
0 siblings, 2 replies; 14+ messages in thread
From: Christoph Hellwig @ 2021-09-17 12:59 UTC (permalink / raw)
To: Jan Kara
Cc: Eric Sandeen, linux-xfs, linux-ext4, linux-fsdevel, dan.j.williams
On Fri, Sep 17, 2021 at 11:47:07AM +0200, Jan Kara wrote:
> On Wed 15-09-21 12:22:41, Eric Sandeen wrote:
> > As there seems to be no significant outstanding concern about
> > dax on ext2 at this point, remove the scary EXPERIMENTAL
> > warning when in use.
> >
> > Signed-off-by: Eric Sandeen <sandeen@redhat.com>
>
> Agreed. Do you want my ack or should I just merge this patch?
Please do not merge it. The whole DAX path is still a mess and should
not be elevated to non-EXPERMINTAL state in this form.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 3/3] ext2: remove dax EXPERIMENTAL warning
2021-09-17 12:59 ` Christoph Hellwig
@ 2021-09-17 14:09 ` Eric Sandeen
2021-09-22 2:36 ` Darrick J. Wong
1 sibling, 0 replies; 14+ messages in thread
From: Eric Sandeen @ 2021-09-17 14:09 UTC (permalink / raw)
To: Christoph Hellwig, Jan Kara
Cc: linux-xfs, linux-ext4, linux-fsdevel, dan.j.williams
On 9/17/21 7:59 AM, Christoph Hellwig wrote:
> On Fri, Sep 17, 2021 at 11:47:07AM +0200, Jan Kara wrote:
>> On Wed 15-09-21 12:22:41, Eric Sandeen wrote:
>>> As there seems to be no significant outstanding concern about
>>> dax on ext2 at this point, remove the scary EXPERIMENTAL
>>> warning when in use.
>>>
>>> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
>>
>> Agreed. Do you want my ack or should I just merge this patch?
>
> Please do not merge it. The whole DAX path is still a mess and should
> not be elevated to non-EXPERMINTAL state in this form.
Hi Christoph, "a mess" is tough to work with. What work remains before
we can lift the warning?
-Eric
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 3/3] ext2: remove dax EXPERIMENTAL warning
2021-09-17 12:59 ` Christoph Hellwig
2021-09-17 14:09 ` Eric Sandeen
@ 2021-09-22 2:36 ` Darrick J. Wong
2021-09-22 5:25 ` Christoph Hellwig
1 sibling, 1 reply; 14+ messages in thread
From: Darrick J. Wong @ 2021-09-22 2:36 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Jan Kara, Eric Sandeen, linux-xfs, linux-ext4, linux-fsdevel,
dan.j.williams
On Fri, Sep 17, 2021 at 01:59:10PM +0100, Christoph Hellwig wrote:
> On Fri, Sep 17, 2021 at 11:47:07AM +0200, Jan Kara wrote:
> > On Wed 15-09-21 12:22:41, Eric Sandeen wrote:
> > > As there seems to be no significant outstanding concern about
> > > dax on ext2 at this point, remove the scary EXPERIMENTAL
> > > warning when in use.
> > >
> > > Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> >
> > Agreed. Do you want my ack or should I just merge this patch?
>
> Please do not merge it. The whole DAX path is still a mess and should
> not be elevated to non-EXPERMINTAL state in this form.
Hi Christoph,
'still a mess' isn't all that useful for figuring out what still needs
to be done and splitting up the work. Do you have items beyond my own
list below?
- still arguing over what exactly FALLOC_FL_ZERO_REINIT_WHATEVER_PONIES
should be doing
- no reflink support, encompassing:
- hwpoison from mmap regions really ought to tell the fs that bad stuff
happened
- mm rmap can't handle more than one owner
--D
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 3/3] ext2: remove dax EXPERIMENTAL warning
2021-09-22 2:36 ` Darrick J. Wong
@ 2021-09-22 5:25 ` Christoph Hellwig
0 siblings, 0 replies; 14+ messages in thread
From: Christoph Hellwig @ 2021-09-22 5:25 UTC (permalink / raw)
To: Darrick J. Wong
Cc: Christoph Hellwig, Jan Kara, Eric Sandeen, linux-xfs, linux-ext4,
linux-fsdevel, dan.j.williams
On Tue, Sep 21, 2021 at 07:36:22PM -0700, Darrick J. Wong wrote:
> 'still a mess' isn't all that useful for figuring out what still needs
> to be done and splitting up the work. Do you have items beyond my own
> list below?
>
> - still arguing over what exactly FALLOC_FL_ZERO_REINIT_WHATEVER_PONIES
> should be doing
> - no reflink support, encompassing:
> - hwpoison from mmap regions really ought to tell the fs that bad stuff
> happened
> - mm rmap can't handle more than one owner
My main really big item is that we're still mounting through a fake
block device, suporting partitions and all that crap. We need to sort
out the whole story of how pmem/nvdimm is actually treated, because
what we have right now is not sustainable at all.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 0/3 RFC] Remove DAX experimental warnings
2021-09-15 17:22 [PATCH 0/3 RFC] Remove DAX experimental warnings Eric Sandeen
` (2 preceding siblings ...)
2021-09-15 17:22 ` [PATCH 3/3] ext2: " Eric Sandeen
@ 2021-09-15 18:35 ` Dan Williams
2021-09-15 18:48 ` Eric Sandeen
3 siblings, 1 reply; 14+ messages in thread
From: Dan Williams @ 2021-09-15 18:35 UTC (permalink / raw)
To: Eric Sandeen; +Cc: linux-xfs, linux-ext4, linux-fsdevel, Shiyang Ruan
On Wed, Sep 15, 2021 at 10:23 AM Eric Sandeen <sandeen@redhat.com> wrote:
>
> For six years now, when mounting xfs, ext4, or ext2 with dax, the drivers
> have logged "DAX enabled. Warning: EXPERIMENTAL, use at your own risk."
>
> IIRC, dchinner added this to the original XFS patchset, and Dan Williams
> followed suit for ext4 and ext2.
>
> After brief conversations with some ext4 and xfs developers and maintainers,
> it seems that it may be time to consider removing this warning.
>
> For XFS, we had been holding out for reflink+dax capability, but proposals
> which had seemed promising now appear to be indefinitely stalled, and
> I think we might want to consider that dax-without-reflink is no longer
> EXPERIMENTAL, while dax-with-reflink is simply an unimplemented future
> feature.
I do regret my gap in engagement since the last review as I got
distracted by CXL, but I've recently gotten my act together and picked
up the review again to help get Ruan's patches over the goal line [1].
I am currently awaiting Ruan's response to latest review feedback
(looks like a new posting this morning). During that review Christoph
identified some cleanups that would help Ruan's series, and those are
now merged upstream [2]. The last remaining stumbling block (further
block-device entanglements with dax-devices) I noted here [2]. The
proposal is to consider eliding device-mapper dax-reflink support for
now and proceed with just xfs-on-/dev/pmem until Mike, Jens, and
Christoph can chime in on the future of dax on block devices.
As far as I can see we have line of sight to land xfs-dax-reflink
support for v5.16, does anyone see that differently at this point?
[1]: https://lore.kernel.org/linux-xfs/CAPcyv4h0p+zD5tsT8HDUpNq_ZDCqo249KsmPLX-U8ia146r2Tg@mail.gmail.com/
[2]: https://lore.kernel.org/linux-xfs/CAPcyv4ic+LDagR8uF18tO3cCb6t=YTZNkAOK=vnsnERqY6Ze_g@mail.gmail.com/
[3]: https://lore.kernel.org/nvdimm/CAPcyv4hvzS1c01BweBkgDsjg=VGnaUUKi7b6j+1X=Rqzzm961Q@mail.gmail.com/
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH 0/3 RFC] Remove DAX experimental warnings
2021-09-15 18:35 ` [PATCH 0/3 RFC] Remove DAX experimental warnings Dan Williams
@ 2021-09-15 18:48 ` Eric Sandeen
2021-09-15 18:59 ` Dan Williams
0 siblings, 1 reply; 14+ messages in thread
From: Eric Sandeen @ 2021-09-15 18:48 UTC (permalink / raw)
To: Dan Williams, Eric Sandeen
Cc: linux-xfs, linux-ext4, linux-fsdevel, Shiyang Ruan
On 9/15/21 1:35 PM, Dan Williams wrote:
> On Wed, Sep 15, 2021 at 10:23 AM Eric Sandeen <sandeen@redhat.com> wrote:
>>
>> For six years now, when mounting xfs, ext4, or ext2 with dax, the drivers
>> have logged "DAX enabled. Warning: EXPERIMENTAL, use at your own risk."
>>
>> IIRC, dchinner added this to the original XFS patchset, and Dan Williams
>> followed suit for ext4 and ext2.
>>
>> After brief conversations with some ext4 and xfs developers and maintainers,
>> it seems that it may be time to consider removing this warning.
>>
>> For XFS, we had been holding out for reflink+dax capability, but proposals
>> which had seemed promising now appear to be indefinitely stalled, and
>> I think we might want to consider that dax-without-reflink is no longer
>> EXPERIMENTAL, while dax-with-reflink is simply an unimplemented future
>> feature.
>
> I do regret my gap in engagement since the last review as I got
> distracted by CXL, but I've recently gotten my act together and picked
> up the review again to help get Ruan's patches over the goal line [1].
> I am currently awaiting Ruan's response to latest review feedback
> (looks like a new posting this morning). During that review Christoph
> identified some cleanups that would help Ruan's series, and those are
> now merged upstream [2]. The last remaining stumbling block (further
> block-device entanglements with dax-devices) I noted here [2]. The
> proposal is to consider eliding device-mapper dax-reflink support for
> now and proceed with just xfs-on-/dev/pmem until Mike, Jens, and
> Christoph can chime in on the future of dax on block devices.
>
> As far as I can see we have line of sight to land xfs-dax-reflink
> support for v5.16, does anyone see that differently at this point?
Thanks for that update, Dan. I'm wondering, even if we have renewed
hopes and dreams for dax+reflink, would it make sense to go ahead and
declare dax without reflink non-experimental, and tag dax+reflink as
a new "EXPERIMENTAL feature if and when it lands?
-Eric
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 0/3 RFC] Remove DAX experimental warnings
2021-09-15 18:48 ` Eric Sandeen
@ 2021-09-15 18:59 ` Dan Williams
0 siblings, 0 replies; 14+ messages in thread
From: Dan Williams @ 2021-09-15 18:59 UTC (permalink / raw)
To: Eric Sandeen
Cc: Eric Sandeen, linux-xfs, linux-ext4, linux-fsdevel, Shiyang Ruan
On Wed, Sep 15, 2021 at 11:49 AM Eric Sandeen <sandeen@sandeen.net> wrote:
>
> On 9/15/21 1:35 PM, Dan Williams wrote:
> > On Wed, Sep 15, 2021 at 10:23 AM Eric Sandeen <sandeen@redhat.com> wrote:
> >>
> >> For six years now, when mounting xfs, ext4, or ext2 with dax, the drivers
> >> have logged "DAX enabled. Warning: EXPERIMENTAL, use at your own risk."
> >>
> >> IIRC, dchinner added this to the original XFS patchset, and Dan Williams
> >> followed suit for ext4 and ext2.
> >>
> >> After brief conversations with some ext4 and xfs developers and maintainers,
> >> it seems that it may be time to consider removing this warning.
> >>
> >> For XFS, we had been holding out for reflink+dax capability, but proposals
> >> which had seemed promising now appear to be indefinitely stalled, and
> >> I think we might want to consider that dax-without-reflink is no longer
> >> EXPERIMENTAL, while dax-with-reflink is simply an unimplemented future
> >> feature.
> >
> > I do regret my gap in engagement since the last review as I got
> > distracted by CXL, but I've recently gotten my act together and picked
> > up the review again to help get Ruan's patches over the goal line [1].
> > I am currently awaiting Ruan's response to latest review feedback
> > (looks like a new posting this morning). During that review Christoph
> > identified some cleanups that would help Ruan's series, and those are
> > now merged upstream [2]. The last remaining stumbling block (further
> > block-device entanglements with dax-devices) I noted here [2]. The
> > proposal is to consider eliding device-mapper dax-reflink support for
> > now and proceed with just xfs-on-/dev/pmem until Mike, Jens, and
> > Christoph can chime in on the future of dax on block devices.
> >
> > As far as I can see we have line of sight to land xfs-dax-reflink
> > support for v5.16, does anyone see that differently at this point?
>
> Thanks for that update, Dan. I'm wondering, even if we have renewed
> hopes and dreams for dax+reflink, would it make sense to go ahead and
> declare dax without reflink non-experimental, and tag dax+reflink as
> a new "EXPERIMENTAL feature if and when it lands?
As I replied to the xfs patch in your series, I say "yes" EXPERIMENTAL
can go now, because the concern was reflink support might regress
dax-semantics wrt MAP_SYNC and the like. That concern seems to be
avoided by the current direction.
^ permalink raw reply [flat|nested] 14+ messages in thread