Re: [RFC][PATCH 04/13] do_utimes_path(): import pathname only once

Jan Kara
2025-11-13T10:16:00Z

On Sun 09-11-25 06:37:36, Al Viro wrote:
> Convert the user_path_at() call inside a retry loop into getname_flags() +
> filename_lookup() + putname() and leave only filename_lookup() inside
> the loop.
>
> Since we have the default logics for use of LOOKUP_EMPTY (passed iff
> AT_EMPTY_PATH is present in flags), just use getname_uflags() and
> don't bother with setting LOOKUP_EMPTY in lookup_flags - getname_uflags()
> will pass the right thing to getname_flags() and filename_lookup()
> doesn't care about LOOKUP_EMPTY at all.
>
> The things could be further simplified by use of cleanup.h stuff, but
> let's not clutter the patch with that.
>
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/utimes.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/fs/utimes.c b/fs/utimes.c
> index c7c7958e57b2..262a4ddeb9cc 100644
> --- a/fs/utimes.c
> +++ b/fs/utimes.c
> @@ -8,6 +8,7 @@
> #include <linux/compat.h>
> #include <asm/unistd.h>
> #include <linux/filelock.h>
> +#include "internal.h"
>
> static bool nsec_valid(long nsec)
> {
> @@ -82,27 +83,27 @@ static int do_utimes_path(int dfd, const char __user *filename,
> {
> struct path path;
> int lookup_flags = 0, error;
> + struct filename *name;
>
> if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
> return -EINVAL;
>
> if (!(flags & AT_SYMLINK_NOFOLLOW))
> lookup_flags |= LOOKUP_FOLLOW;
> - if (flags & AT_EMPTY_PATH)
> - lookup_flags |= LOOKUP_EMPTY;
> + name = getname_uflags(filename, flags);
>
> retry:
> - error = user_path_at(dfd, filename, lookup_flags, &path);
> + error = filename_lookup(dfd, name, lookup_flags, &path, NULL);
> if (error)
> - return error;
> -
> + goto out;
> error = vfs_utimes(&path, times);
> path_put(&path);
> if (retry_estale(error, lookup_flags)) {
> lookup_flags |= LOOKUP_REVAL;
> goto retry;
> }
> -
> +out:
> + putname(name);
> return error;
> }
>
> --
> 2.47.3
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR