Re: [RFC PATCH 4/7] ext2: Use dax_is_supported()

[Mathieu Desnoyers]

On 2024-01-30 06:33, Jan Kara wrote:
> On Mon 29-01-24 16:06:28, Mathieu Desnoyers wrote:
> > Use dax_is_supported() to validate whether the architecture has
> > virtually aliased caches at mount time.
> >
> > This is relevant for architectures which require a dynamic check
> > to validate whether they have virtually aliased data caches
> > (ARCH_HAS_CACHE_ALIASING_DYNAMIC=y).
> >
> > Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches")
> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> > Cc: Jan Kara <jack@xxxxxxxx>
> > Cc: linux-ext4@xxxxxxxxxxxxxxx
> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> > Cc: linux-mm@xxxxxxxxx
> > Cc: linux-arch@xxxxxxxxxxxxxxx
> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> > Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
> > Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
> > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> > Cc: nvdimm@xxxxxxxxxxxxxxx
> > Cc: linux-cxl@xxxxxxxxxxxxxxx
>
> Looks good to me (although I share Dave's opinion it would be nice to CC
> the whole series to fsdevel - luckily we have lore these days so it is not
> that tedious to find the whole series :)). Feel free to add:
>
> Acked-by: Jan Kara <jack@xxxxxxx>

Hi Jan,

Thanks for looking at it! I will do significant changes for v2, so
I will hold on before integrating your acked-by if it's OK with you.

Thanks!

Mathieu

> 								Honza
>
> > ---
> >   fs/ext2/super.c | 14 +++++++-------
> >   1 file changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/fs/ext2/super.c b/fs/ext2/super.c
> > index 01f9addc8b1f..0398e7a90eb6 100644
> > --- a/fs/ext2/super.c
> > +++ b/fs/ext2/super.c
> > @@ -585,13 +585,13 @@ static int parse_options(char *options, struct super_block *sb,
> >   			set_opt(opts->s_mount_opt, XIP);
> >   			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");
> > -#endif
> > +			if (dax_is_supported()) {
> > +				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");
> > +			}
> >   			break;
> >   
> >   #if defined(CONFIG_QUOTA)
> > --
> > 2.39.2

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com