Re: [PATCH 2/4] usertools: add option to change mount point owner

From: Stephen Hemminger <stephen@networkplumber.org>
To: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
Cc: <dev@dpdk.org>, Thomas Monjalon <thomas@monjalon.net>
Subject: Re: [PATCH 2/4] usertools: add option to change mount point owner
Date: Tue, 7 Jun 2022 17:00:28 -0700	[thread overview]
Message-ID: <20220607170028.48e04a5e@hermes.local> (raw)
In-Reply-To: <20220607234949.2311884-3-dkozlyuk@nvidia.com>

On Wed, 8 Jun 2022 02:49:47 +0300
Dmitry Kozlyuk <dkozlyuk@nvidia.com> wrote:

>  
> -def mount_huge(pagesize, mountpoint):
> +def mount_huge(pagesize, mountpoint, owner):
>      '''Mount the huge TLB file system'''
>      if mountpoint in get_mountpoints():
>          print(mountpoint, "already mounted")
> @@ -180,6 +180,8 @@ def mount_huge(pagesize, mountpoint):
>          cmd += ' -o pagesize={}'.format(pagesize * 1024)
>      cmd += ' nodev ' + mountpoint
>      os.system(cmd)
> +    if owner:
> +        os.system('chown {} {}'.format(owner, mountpoint))
>  

The hugetlb filesystem type already supports set owner.
Please use that instead of an additional chown command.

https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt

If the user applications are going to request huge pages using mmap system
call, then it is required that system administrator mount a file system of
type hugetlbfs:

  mount -t hugetlbfs \
	-o uid=<value>,gid=<value>,mode=<value>,pagesize=<value>,size=<value>,\
	min_size=<value>,nr_inodes=<value> none /mnt/huge