Re: [PATCH 1/3] fs: sort out cosmetic differences between stat funcs and add predicts

From: Jan Kara
Date: Tue Apr 08 2025 - 06:24:42 EST


On Mon 07-04-25 01:58:04, Mateusz Guzik wrote:
> This is a nop, but I did verify asm improves.
>
> Signed-off-by: Mateusz Guzik <mjguzik@xxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> fs/stat.c | 35 ++++++++++++++++++++---------------
> 1 file changed, 20 insertions(+), 15 deletions(-)
>
> diff --git a/fs/stat.c b/fs/stat.c
> index f13308bfdc98..b79ddb83914b 100644
> --- a/fs/stat.c
> +++ b/fs/stat.c
> @@ -241,7 +241,7 @@ int vfs_getattr(const struct path *path, struct kstat *stat,
> int retval;
>
> retval = security_inode_getattr(path);
> - if (retval)
> + if (unlikely(retval))
> return retval;
> return vfs_getattr_nosec(path, stat, request_mask, query_flags);
> }
> @@ -421,7 +421,7 @@ SYSCALL_DEFINE2(stat, const char __user *, filename,
> int error;
>
> error = vfs_stat(filename, &stat);
> - if (error)
> + if (unlikely(error))
> return error;
>
> return cp_old_stat(&stat, statbuf);
> @@ -434,7 +434,7 @@ SYSCALL_DEFINE2(lstat, const char __user *, filename,
> int error;
>
> error = vfs_lstat(filename, &stat);
> - if (error)
> + if (unlikely(error))
> return error;
>
> return cp_old_stat(&stat, statbuf);
> @@ -443,12 +443,13 @@ SYSCALL_DEFINE2(lstat, const char __user *, filename,
> SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
> {
> struct kstat stat;
> - int error = vfs_fstat(fd, &stat);
> + int error;
>
> - if (!error)
> - error = cp_old_stat(&stat, statbuf);
> + error = vfs_fstat(fd, &stat);
> + if (unlikely(error))
> + return error;
>
> - return error;
> + return cp_old_stat(&stat, statbuf);
> }
>
> #endif /* __ARCH_WANT_OLD_STAT */
> @@ -502,10 +503,12 @@ SYSCALL_DEFINE2(newstat, const char __user *, filename,
> struct stat __user *, statbuf)
> {
> struct kstat stat;
> - int error = vfs_stat(filename, &stat);
> + int error;
>
> - if (error)
> + error = vfs_stat(filename, &stat);
> + if (unlikely(error))
> return error;
> +
> return cp_new_stat(&stat, statbuf);
> }
>
> @@ -516,7 +519,7 @@ SYSCALL_DEFINE2(newlstat, const char __user *, filename,
> int error;
>
> error = vfs_lstat(filename, &stat);
> - if (error)
> + if (unlikely(error))
> return error;
>
> return cp_new_stat(&stat, statbuf);
> @@ -530,8 +533,9 @@ SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
> int error;
>
> error = vfs_fstatat(dfd, filename, &stat, flag);
> - if (error)
> + if (unlikely(error))
> return error;
> +
> return cp_new_stat(&stat, statbuf);
> }
> #endif
> @@ -539,12 +543,13 @@ SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
> SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
> {
> struct kstat stat;
> - int error = vfs_fstat(fd, &stat);
> + int error;
>
> - if (!error)
> - error = cp_new_stat(&stat, statbuf);
> + error = vfs_fstat(fd, &stat);
> + if (unlikely(error))
> + return error;
>
> - return error;
> + return cp_new_stat(&stat, statbuf);
> }
> #endif
>
> --
> 2.43.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR