[patch] random.4: Update description about O_NONBLOCK flag

[patch] random.4: Update description about O_NONBLOCK flag

[GUO Zihua]

The O_NONBLOCK flag has been removed since Linux 5.6 and this patch
states this change in man page.

The commit that introduce this change in the Linux kernel is
30c08efec888 ("random: make /dev/random be almost like /dev/urandom")

Signed-off-by: GUO Zihua <guozihua@huawei.com>
---
 man4/random.4 | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/man4/random.4 b/man4/random.4
index bea860e7f0d7..5b2094931449 100644
--- a/man4/random.4
+++ b/man4/random.4
@@ -68,7 +68,12 @@ high quality randomness, and can afford indeterminate delays.
 .PP
 When the entropy pool is empty, reads from \fI/dev/random\fP will block
 until additional environmental noise is gathered.
-If
+Since Linux 5.6, the
+.B O_NONBLOCK
+flag is removed as
+.I /dev/random
+will no longer block except during 
+early boot process. In eariler versions, if
 .BR open (2)
 is called for
 .I /dev/random
-- 
2.36.0

Re: [patch] random.4: Update description about O_NONBLOCK flag

[Alejandro Colomar]

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Hi,

On 8/2/22 05:53, GUO Zihua wrote:
> The O_NONBLOCK flag has been removed since Linux 5.6 and this patch
> states this change in man page.
> 
> The commit that introduce this change in the Linux kernel is
> 30c08efec888 ("random: make /dev/random be almost like /dev/urandom")
> 
> Signed-off-by: GUO Zihua <guozihua@huawei.com>

Please see a minor formatting issue below.
Thanks for the patch.

Cheers,

Alex

> ---
>   man4/random.4 | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/man4/random.4 b/man4/random.4
> index bea860e7f0d7..5b2094931449 100644
> --- a/man4/random.4
> +++ b/man4/random.4
> @@ -68,7 +68,12 @@ high quality randomness, and can afford indeterminate delays.
>   .PP
>   When the entropy pool is empty, reads from \fI/dev/random\fP will block
>   until additional environmental noise is gathered.
> -If
> +Since Linux 5.6, the
> +.B O_NONBLOCK
> +flag is removed as
> +.I /dev/random
> +will no longer block except during
> +early boot process. In eariler versions, if

s/\. /.\n/

See man-pages(7):
    Use semantic newlines
        In  the  source of a manual page, new sentences should be
        started on new lines, long sentences should be split into
        lines at clause breaks (commas, semicolons,  colons,  and
        so on), and long clauses should be split at phrase bound‐
        aries.   This  convention,  sometimes  known as "semantic
        newlines", makes it easier to see the effect of  patches,
        which often operate at the level of individual sentences,
        clauses, or phrases.


>   .BR open (2)
>   is called for
>   .I /dev/random

-- 
Alejandro Colomar
<http://www.alejandro-colomar.es/>

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Re: [patch] random.4: Update description about O_NONBLOCK flag

[Florian Weimer]

* GUO Zihua:

> diff --git a/man4/random.4 b/man4/random.4
> index bea860e7f0d7..5b2094931449 100644
> --- a/man4/random.4
> +++ b/man4/random.4
> @@ -68,7 +68,12 @@ high quality randomness, and can afford indeterminate delays.
>  .PP
>  When the entropy pool is empty, reads from \fI/dev/random\fP will block
>  until additional environmental noise is gathered.
> -If
> +Since Linux 5.6, the
> +.B O_NONBLOCK
> +flag is removed as
> +.I /dev/random
> +will no longer block except during 
> +early boot process. In eariler versions, if
>  .BR open (2)
>  is called for
>  .I /dev/random

Is ”is removed” correct here?  Should it be “is ignored” instead?

Thanks,
Florian

Re: [patch] random.4: Update description about O_NONBLOCK flag

[Guozihua (Scott)]

On 2022/8/3 15:27, Florian Weimer wrote:
> * GUO Zihua:
> 
>> diff --git a/man4/random.4 b/man4/random.4
>> index bea860e7f0d7..5b2094931449 100644
>> --- a/man4/random.4
>> +++ b/man4/random.4
>> @@ -68,7 +68,12 @@ high quality randomness, and can afford indeterminate delays.
>>   .PP
>>   When the entropy pool is empty, reads from \fI/dev/random\fP will block
>>   until additional environmental noise is gathered.
>> -If
>> +Since Linux 5.6, the
>> +.B O_NONBLOCK
>> +flag is removed as
>> +.I /dev/random
>> +will no longer block except during
>> +early boot process. In eariler versions, if
>>   .BR open (2)
>>   is called for
>>   .I /dev/random
> 
> Is ”is removed” correct here?  Should it be “is ignored” instead?
> 
> Thanks,
> Florian
> 
> .

Hi Florian

Indeed this could be even more precise.

-- 
Best
GUO Zihua