[V9fs-developer] [PATCH] fs/9p: don't set SB_NOATIME by default

[V9fs-developer] [PATCH] fs/9p: don't set SB_NOATIME by default

[jiangyiwen]

User use some syscall, for example mmap(v9fs_file_mmap), it will not
update atime even if user's mnt_flags have MNT_NOATIME, because
v9fs default set SB_NOATIME in v9fs_set_super.

For supporting access time is updated when user mount with relatime,
we should clear SB_NOATIME by default.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
---
 fs/9p/vfs_super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index af03c2a..48ce504 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -94,7 +94,7 @@ static int v9fs_set_super(struct super_block *s, void *data)
 	if (v9ses->cache)
 		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE;

-	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME;
+	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
 	if (!v9ses->cache)
 		sb->s_flags |= SB_SYNCHRONOUS;

-- 
1.8.3.1

Re: [V9fs-developer] [PATCH] fs/9p: don't set SB_NOATIME by default

[jiangyiwen]

On 2018/2/9 14:13, jiangyiwen wrote:
> User use some syscall, for example mmap(v9fs_file_mmap), it will not
> update atime even if user's mnt_flags have MNT_NOATIME, because
> v9fs default set SB_NOATIME in v9fs_set_super.
> 
> For supporting access time is updated when user mount with relatime,
> we should clear SB_NOATIME by default.
> 
> Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
> ---
>  fs/9p/vfs_super.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
> index af03c2a..48ce504 100644
> --- a/fs/9p/vfs_super.c
> +++ b/fs/9p/vfs_super.c
> @@ -94,7 +94,7 @@ static int v9fs_set_super(struct super_block *s, void *data)
>  	if (v9ses->cache)
>  		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE;
> 
> -	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME;
> +	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
>  	if (!v9ses->cache)
>  		sb->s_flags |= SB_SYNCHRONOUS;
> 
Hi Alexander Viro and Eric,

My patch has already sent two weeks, but nobody help me
to review, I have a question about now who is the v9fs's
maintainer? Or who can help me review the patch?

I hope v9fs's maintainer can give me some advices or
merge into the mainline if it has no problem.

Thanks,
Yiwen.

Re: [V9fs-developer] [PATCH] fs/9p: don't set SB_NOATIME by default

[jiangyiwen]

On 2018/2/24 10:47, jiangyiwen wrote:
> On 2018/2/9 14:13, jiangyiwen wrote:
>> User use some syscall, for example mmap(v9fs_file_mmap), it will not
>> update atime even if user's mnt_flags have MNT_NOATIME, because
>> v9fs default set SB_NOATIME in v9fs_set_super.
>>
>> For supporting access time is updated when user mount with relatime,
>> we should clear SB_NOATIME by default.
>>
>> Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
>> ---
>>  fs/9p/vfs_super.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
>> index af03c2a..48ce504 100644
>> --- a/fs/9p/vfs_super.c
>> +++ b/fs/9p/vfs_super.c
>> @@ -94,7 +94,7 @@ static int v9fs_set_super(struct super_block *s, void *data)
>>  	if (v9ses->cache)
>>  		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE;
>>
>> -	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME;
>> +	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
>>  	if (!v9ses->cache)
>>  		sb->s_flags |= SB_SYNCHRONOUS;
>>
> Hi Alexander Viro and Eric,
> 
> My patch has already sent two weeks, but nobody help me
> to review, I have a question about now who is the v9fs's
> maintainer? Or who can help me review the patch?
> 
> I hope v9fs's maintainer can give me some advices or
> merge into the mainline if it has no problem.
> 
> Thanks,
> Yiwen.
> 
Hi Andrew,

My patch has already sent more than two weeks, but nobody
help me to review, I have a question about now who is the
v9fs's maintainer? Or who can help me review the patch?

I hope v9fs's maintainer can give me some advices or
merge into the mainline if it has no problem.

Thanks,
Yiwen.

Re: [V9fs-developer] [PATCH] fs/9p: don't set SB_NOATIME by default

[Bo YU]

Hi,
I think you would better to modify the subject line without
[V9fs-developers].
On Mon, Feb 26, 2018 at 09:34:49AM +0800, jiangyiwen wrote:
>On 2018/2/24 10:47, jiangyiwen wrote:
>> On 2018/2/9 14:13, jiangyiwen wrote:
>>> User use some syscall, for example mmap(v9fs_file_mmap), it will not
>>> update atime even if user's mnt_flags have MNT_NOATIME, because
>>> v9fs default set SB_NOATIME in v9fs_set_super.
>>>
>>> For supporting access time is updated when user mount with relatime,
>>> we should clear SB_NOATIME by default.
>>>
>>> Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
>>> ---
>>>  fs/9p/vfs_super.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
>>> index af03c2a..48ce504 100644
>>> --- a/fs/9p/vfs_super.c
>>> +++ b/fs/9p/vfs_super.c
>>> @@ -94,7 +94,7 @@ static int v9fs_set_super(struct super_block *s, void *data)
>>>  	if (v9ses->cache)
>>>  		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE;
>>>
>>> -	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME;
>>> +	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
>>>  	if (!v9ses->cache)
>>>  		sb->s_flags |= SB_SYNCHRONOUS;
>>>
>> Hi Alexander Viro and Eric,
>>
>> My patch has already sent two weeks, but nobody help me
>> to review, I have a question about now who is the v9fs's
>> maintainer? Or who can help me review the patch?
>>
>> I hope v9fs's maintainer can give me some advices or
>> merge into the mainline if it has no problem.
>>
>> Thanks,
>> Yiwen.
>>
>Hi Andrew,
>
>My patch has already sent more than two weeks, but nobody
>help me to review, I have a question about now who is the
>v9fs's maintainer? Or who can help me review the patch?
>
There is no maintainer with V9fs  in get_maintain.pl and V9fs git tree
laterest commit before two years.so,situation become bad.
Maybe you eamil linus directly,although this is't good
>I hope v9fs's maintainer can give me some advices or
>merge into the mainline if it has no problem.
>
>Thanks,
>Yiwen.
>
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Re: [V9fs-developer] [PATCH] fs/9p: don't set SB_NOATIME by default

[jiangyiwen]

On 2018/3/28 7:15, Andrew Morton wrote:
> On Tue, 27 Mar 2018 09:50:47 +0800 jiangyiwen <jiangyiwen@huawei.com> wrote:
> 
>> User use some syscall, for example mmap(v9fs_file_mmap), it will not
>> update atime even if user's mnt_flags without MNT_NOATIME, because
>> v9fs default set SB_NOATIME in v9fs_set_super.
>>
>> For supporting access time is updated when user mount with relatime,
>> we should not set SB_NOATIME by default.
>>
>> ...
>>
>> --- a/fs/9p/vfs_super.c
>> +++ b/fs/9p/vfs_super.c
>> @@ -94,7 +94,7 @@ static int v9fs_set_super(struct super_block *s, void *data)
>>  	if (v9ses->cache)
>>  		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE;
>>
>> -	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME;
>> +	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
>>  	if (!v9ses->cache)
>>  		sb->s_flags |= SB_SYNCHRONOUS;
>>
> 
> So strictly speaking, this is a non-backward-compatible change, yes?
> 
> Please describe the circumstances under which an existing user might be
> harmed by this.  I *think* such harm will occur if the user was already
> using 'mount -o relatime', yes?  They previously weren't getting
> relatime treatment, but now they will, and things will be a little slower.
> 

Yes, after using this change, if user was already using 'mount -o relatime',
their atime will be changed, and some operations will result in slower
performance, but I think user should use 'noatime' option if they hope
their file's atime is not updated and user should not depend on the
internal implement.

> If correct, that sounds acceptable.
> 
> .
> 

Re: [V9fs-developer] [PATCH] fs/9p: don't set SB_NOATIME by default

[Andrew Morton]

On Tue, 27 Mar 2018 09:50:47 +0800 jiangyiwen <jiangyiwen@huawei.com> wrote:

> User use some syscall, for example mmap(v9fs_file_mmap), it will not
> update atime even if user's mnt_flags without MNT_NOATIME, because
> v9fs default set SB_NOATIME in v9fs_set_super.
> 
> For supporting access time is updated when user mount with relatime,
> we should not set SB_NOATIME by default.
> 
> ...
>
> --- a/fs/9p/vfs_super.c
> +++ b/fs/9p/vfs_super.c
> @@ -94,7 +94,7 @@ static int v9fs_set_super(struct super_block *s, void *data)
>  	if (v9ses->cache)
>  		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE;
> 
> -	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME;
> +	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
>  	if (!v9ses->cache)
>  		sb->s_flags |= SB_SYNCHRONOUS;
> 

So strictly speaking, this is a non-backward-compatible change, yes?

Please describe the circumstances under which an existing user might be
harmed by this.  I *think* such harm will occur if the user was already
using 'mount -o relatime', yes?  They previously weren't getting
relatime treatment, but now they will, and things will be a little slower.

If correct, that sounds acceptable.

[V9fs-developer] [PATCH] fs/9p: don't set SB_NOATIME by default

[jiangyiwen]

User use some syscall, for example mmap(v9fs_file_mmap), it will not
update atime even if user's mnt_flags without MNT_NOATIME, because
v9fs default set SB_NOATIME in v9fs_set_super.

For supporting access time is updated when user mount with relatime,
we should not set SB_NOATIME by default.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
---
 fs/9p/vfs_super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index af03c2a..48ce504 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -94,7 +94,7 @@ static int v9fs_set_super(struct super_block *s, void *data)
 	if (v9ses->cache)
 		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE;

-	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME;
+	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
 	if (!v9ses->cache)
 		sb->s_flags |= SB_SYNCHRONOUS;

-- 
1.8.3.1