fs: refactor do_utimes

Split out one helper each for path vs fd based operations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/utimes.c

@@ -70,59 +70,27 @@ static int utimes_common(const struct path *path, struct timespec64 *times)
 	return error;
 }
 
-/*
- * do_utimes - change times on filename or file descriptor
- * @dfd: open file descriptor, -1 or AT_FDCWD
- * @filename: path name or NULL
- * @times: new times or NULL
- * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
- *
- * If filename is NULL and dfd refers to an open file, then operate on
- * the file.  Otherwise look up filename, possibly using dfd as a
- * starting point.
- *
- * If times==NULL, set access and modification to current time,
- * must be owner or have write permission.
- * Else, update from *times, must be owner or super user.
- */
-long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
-	       int flags)
+static int do_utimes_path(int dfd, const char __user *filename,
+		struct timespec64 *times, int flags)
 {
-	int error = -EINVAL;
-
-	if (times && (!nsec_valid(times[0].tv_nsec) ||
-		      !nsec_valid(times[1].tv_nsec))) {
-		goto out;
-	}
+	struct path path;
+	int lookup_flags = 0, error;
 
+	if (times &&
+	    (!nsec_valid(times[0].tv_nsec) || !nsec_valid(times[1].tv_nsec)))
+		return -EINVAL;
 	if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
-		goto out;
-
-	if (filename == NULL && dfd != AT_FDCWD) {
-		struct fd f;
-
-		if (flags)
-			goto out;
-
-		f = fdget(dfd);
-		error = -EBADF;
-		if (!f.file)
-			goto out;
-
-		error = utimes_common(&f.file->f_path, times);
-		fdput(f);
-	} else {
-		struct path path;
-		int lookup_flags = 0;
+		return -EINVAL;
 
 	if (!(flags & AT_SYMLINK_NOFOLLOW))
 		lookup_flags |= LOOKUP_FOLLOW;
 	if (flags & AT_EMPTY_PATH)
 		lookup_flags |= LOOKUP_EMPTY;
+
 retry:
 	error = user_path_at(dfd, filename, lookup_flags, &path);
 	if (error)
-			goto out;
+		return error;
 
 	error = utimes_common(&path, times);
 	path_put(&path);
@@ -130,12 +98,52 @@ long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
 		lookup_flags |= LOOKUP_REVAL;
 		goto retry;
 	}
-	}
 
-out:
 	return error;
 }
 
+static int do_utimes_fd(int fd, struct timespec64 *times, int flags)
+{
+	struct fd f;
+	int error;
+
+	if (times &&
+	    (!nsec_valid(times[0].tv_nsec) || !nsec_valid(times[1].tv_nsec)))
+		return -EINVAL;
+	if (flags)
+		return -EINVAL;
+
+	f = fdget(fd);
+	if (!f.file)
+		return -EBADF;
+	error = utimes_common(&f.file->f_path, times);
+	fdput(f);
+	return error;
+}
+
+/*
+ * do_utimes - change times on filename or file descriptor
+ * @dfd: open file descriptor, -1 or AT_FDCWD
+ * @filename: path name or NULL
+ * @times: new times or NULL
+ * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
+ *
+ * If filename is NULL and dfd refers to an open file, then operate on
+ * the file.  Otherwise look up filename, possibly using dfd as a
+ * starting point.
+ *
+ * If times==NULL, set access and modification to current time,
+ * must be owner or have write permission.
+ * Else, update from *times, must be owner or super user.
+ */
+long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
+	       int flags)
+{
+	if (filename == NULL && dfd != AT_FDCWD)
+		return do_utimes_fd(dfd, times, flags);
+	return do_utimes_path(dfd, filename, times, flags);
+}
+
 SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
 		struct __kernel_timespec __user *, utimes, int, flags)
 {