Re: [PATCH 1/2] quota: Change quotactl_path() systcall to an fd-based one

[Sascha Hauer <s.hauer@pengutronix.de>]

Hello Honza,

On Wed, Jun 02, 2021 at 05:15:52PM +0200, Jan Kara wrote:
> Some users have pointed out that path-based syscalls are problematic in
> some environments and at least directory fd argument and possibly also
> resolve flags are desirable for such syscalls. Rather than
> reimplementing all details of pathname lookup and following where it may
> eventually evolve, let's go for full file descriptor based syscall
> similar to how ioctl(2) works since the beginning. Managing of quotas
> isn't performance sensitive so the extra overhead of open does not
> matter and we are able to consume O_PATH descriptors as well which makes
> open cheap anyway. Also for frequent operations (such as retrieving
> usage information for all users) we can reuse single fd and in fact get
> even better performance as well as avoiding races with possible remounts
> etc.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
>  fs/quota/quota.c                  | 27 ++++++++++++---------------
>  include/linux/syscalls.h          |  4 ++--
>  include/uapi/asm-generic/unistd.h |  4 ++--
>  kernel/sys_ni.c                   |  2 +-
>  4 files changed, 17 insertions(+), 20 deletions(-)

Thanks for taking care of this.

I also gave this some testing and it's working ok for me, so at least I
can give you my:

Tested-by: Sascha Hauer <s.hauer@pengutronix.de>

Sascha


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