linux-kernel - Re: [PATCH 17/45] fanotify: add do_fanotify_mark() helper; remove in-kernel call to syscall

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Date:   Mon, 26 Mar 2018 14:25:47 +0200
From:   Jan Kara <jack@...e.cz>
To:     Dominik Brodowski <linux@...inikbrodowski.net>
Cc:     linux-kernel@...r.kernel.org, torvalds@...ux-foundation.org,
        viro@...IV.linux.org.uk, arnd@...db.de, linux-arch@...r.kernel.org,
        Jan Kara <jack@...e.cz>, Amir Goldstein <amir73il@...il.com>
Subject: Re: [PATCH 17/45] fanotify: add do_fanotify_mark() helper; remove
 in-kernel call to syscall

On Thu 22-03-18 10:00:31, Dominik Brodowski wrote:
> Using the fs-internal do_fanotify_mark() helper allows us to get rid of
> the fs-internal call to the sys_fanotify_mark() syscall.
> 
> This patch is part of a series which tries to remove in-kernel calls to
> syscalls. On this basis, the syscall entry path can be streamlined.
> 
> Cc: Jan Kara <jack@...e.cz>
> Cc: Amir Goldstein <amir73il@...il.com>
> Signed-off-by: Dominik Brodowski <linux@...inikbrodowski.net>

Looks good. Feel free to add:

Acked-by: Jan Kara <jack@...e.cz>

								Honza
> ---
>  fs/notify/fanotify/fanotify_user.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index c07eb3d655ea..fa803a58a605 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -820,9 +820,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
>  	return fd;
>  }
>  
> -SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
> -			      __u64, mask, int, dfd,
> -			      const char  __user *, pathname)
> +static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
> +			    int dfd, const char  __user *pathname)
>  {
>  	struct inode *inode = NULL;
>  	struct vfsmount *mnt = NULL;
> @@ -928,13 +927,20 @@ SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
>  	return ret;
>  }
>  
> +SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
> +			      __u64, mask, int, dfd,
> +			      const char  __user *, pathname)
> +{
> +	return do_fanotify_mark(fanotify_fd, flags, mask, dfd, pathname);
> +}
> +
>  #ifdef CONFIG_COMPAT
>  COMPAT_SYSCALL_DEFINE6(fanotify_mark,
>  				int, fanotify_fd, unsigned int, flags,
>  				__u32, mask0, __u32, mask1, int, dfd,
>  				const char  __user *, pathname)
>  {
> -	return sys_fanotify_mark(fanotify_fd, flags,
> +	return do_fanotify_mark(fanotify_fd, flags,
>  #ifdef __BIG_ENDIAN
>  				((__u64)mask0 << 32) | mask1,
>  #else
> -- 
> 2.16.2
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR