linux-ext4 - Re: [RFC PATCH 4/7] ext2: Use dax_is

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Date: Tue, 30 Jan 2024 10:21:04 -0500
From: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
To: Jan Kara <jack@...e.cz>
Cc: Dan Williams <dan.j.williams@...el.com>,
 Vishal Verma <vishal.l.verma@...el.com>, Dave Jiang <dave.jiang@...el.com>,
 linux-kernel@...r.kernel.org, Jan Kara <jack@...e.com>,
 linux-ext4@...r.kernel.org, Andrew Morton <akpm@...ux-foundation.org>,
 Linus Torvalds <torvalds@...ux-foundation.org>, linux-mm@...ck.org,
 linux-arch@...r.kernel.org, Matthew Wilcox <willy@...radead.org>,
 nvdimm@...ts.linux.dev, linux-cxl@...r.kernel.org
Subject: Re: [RFC PATCH 4/7] ext2: Use dax_is_supported()

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@...icios.com>
>> Cc: Jan Kara <jack@...e.com>
>> Cc: linux-ext4@...r.kernel.org
>> Cc: Andrew Morton <akpm@...ux-foundation.org>
>> Cc: Linus Torvalds <torvalds@...ux-foundation.org>
>> Cc: linux-mm@...ck.org
>> Cc: linux-arch@...r.kernel.org
>> Cc: Dan Williams <dan.j.williams@...el.com>
>> Cc: Vishal Verma <vishal.l.verma@...el.com>
>> Cc: Dave Jiang <dave.jiang@...el.com>
>> Cc: Matthew Wilcox <willy@...radead.org>
>> Cc: nvdimm@...ts.linux.dev
>> Cc: linux-cxl@...r.kernel.org
> 
> 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@...e.cz>

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