[PATCH v3] proc.5: document 'subset' mount option.

[PATCH v3] proc.5: document 'subset' mount option.

[technoboy85]

From: Matteo Croce <teknoraver@meta.com>

The 'subset=pid' option was added in commit 6814ef2d, document it.
This option mounts a procfs where only the numeric directories related
to the PIDs are present.

	# mount -t proc proc_pid pid -o subset=pid
	# mount |grep -w proc_pid
	proc_pid on /tmp/proc/pid type proc (rw,relatime,subset=pid)

	# ll -d pid/{1,$$,cmdline,version}
	ls: cannot access 'pid/cmdline': No such file or directory
	ls: cannot access 'pid/version': No such file or directory
	dr-xr-xr-x. 9 root root 0 May 14 09:43 pid/1
	dr-xr-xr-x. 9 root root 0 May 14 09:43 pid/25146

The only non-numeric entries in that procfs instance are
'self' and 'thread-self':

	# ls pid |grep -vx '[[:digit:]]*'
	self
	thread-self
	#

Signed-off-by: Matteo Croce <teknoraver@meta.com>
---
 man/man5/proc.5 | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/man/man5/proc.5 b/man/man5/proc.5
index 8022ca49e..cdb4aa859 100644
--- a/man/man5/proc.5
+++ b/man/man5/proc.5
@@ -105,7 +105,12 @@ This group should be used instead of approaches such as putting
 nonroot users into the
 .BR sudoers (5)
 file.
-.\"
+.RE
+.TP
+.BR subset = pid " (since Linux 5.8)"
+.\" commit 6814ef2d992af09451bbeda4770daa204461329e
+Show only the specified subset of procfs hiding all top level files
+and directories in the procfs that are not related to tasks.
 .SS Overview
 Underneath
 .IR /proc ,
-- 
2.43.0

Re: [PATCH v3] proc.5: document 'subset' mount option.

[Alejandro Colomar]

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Hi Matteo,

On Tue, May 14, 2024 at 10:28:19PM GMT, technoboy85@gmail.com wrote:
> From: Matteo Croce <teknoraver@meta.com>
> 
> The 'subset=pid' option was added in commit 6814ef2d, document it.
> This option mounts a procfs where only the numeric directories related
> to the PIDs are present.
> 
> 	# mount -t proc proc_pid pid -o subset=pid
> 	# mount |grep -w proc_pid
> 	proc_pid on /tmp/proc/pid type proc (rw,relatime,subset=pid)
> 
> 	# ll -d pid/{1,$$,cmdline,version}
> 	ls: cannot access 'pid/cmdline': No such file or directory
> 	ls: cannot access 'pid/version': No such file or directory
> 	dr-xr-xr-x. 9 root root 0 May 14 09:43 pid/1
> 	dr-xr-xr-x. 9 root root 0 May 14 09:43 pid/25146
> 
> The only non-numeric entries in that procfs instance are
> 'self' and 'thread-self':
> 
> 	# ls pid |grep -vx '[[:digit:]]*'
> 	self
> 	thread-self
> 	#
> 
> Signed-off-by: Matteo Croce <teknoraver@meta.com>

I've applied the patch, with minor fixes (grep for 'semantic newlines'
in man-pages(7)), such as a comma, and different line breaks.

<https://www.alejandro-colomar.es/src/alx/linux/man-pages/man-pages.git/commit/?h=contrib&id=dd465607bc5817819f1e90eb66468e7d9cf9e0b1>

Have a lovely night!
Alex

> ---
>  man/man5/proc.5 | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/man/man5/proc.5 b/man/man5/proc.5
> index 8022ca49e..cdb4aa859 100644
> --- a/man/man5/proc.5
> +++ b/man/man5/proc.5
> @@ -105,7 +105,12 @@ This group should be used instead of approaches such as putting
>  nonroot users into the
>  .BR sudoers (5)
>  file.
> -.\"
> +.RE
> +.TP
> +.BR subset = pid " (since Linux 5.8)"
> +.\" commit 6814ef2d992af09451bbeda4770daa204461329e
> +Show only the specified subset of procfs hiding all top level files
> +and directories in the procfs that are not related to tasks.
>  .SS Overview
>  Underneath
>  .IR /proc ,
> -- 
> 2.43.0
> 

-- 
<https://www.alejandro-colomar.es/>

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