[patch 2/4] vfs: utimes cleanup

From: Miklos Szeredi
Date: Tue Jul 01 2008 - 09:02:35 EST


From: Miklos Szeredi <mszeredi@xxxxxxx>

Untange the mess that is do_utimes(). Add kerneldoc comment to
do_utimes().

CC: Ulrich Drepper <drepper@xxxxxxxxxx>
CC: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
---
fs/utimes.c | 114 ++++++++++++++++++++++++++++++++++--------------------------
1 file changed, 65 insertions(+), 49 deletions(-)

Index: linux/fs/utimes.c
===================================================================
--- linux.orig/fs/utimes.c 2008-06-13 11:35:24.000000000 +0200
+++ linux/fs/utimes.c 2008-06-13 11:49:37.000000000 +0200
@@ -48,54 +48,15 @@ static bool nsec_valid(long nsec)
return nsec >= 0 && nsec <= 999999999;
}

-/* 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, char __user *filename, struct timespec *times, int flags)
+static int utimes_common(struct path *path, struct timespec *times)
{
int error;
- struct nameidata nd;
- struct dentry *dentry;
- struct inode *inode;
struct iattr newattrs;
- struct file *f = NULL;
- struct vfsmount *mnt;
-
- error = -EINVAL;
- if (times && (!nsec_valid(times[0].tv_nsec) ||
- !nsec_valid(times[1].tv_nsec))) {
- goto out;
- }
-
- if (flags & ~AT_SYMLINK_NOFOLLOW)
- goto out;
-
- if (filename == NULL && dfd != AT_FDCWD) {
- error = -EINVAL;
- if (flags & AT_SYMLINK_NOFOLLOW)
- goto out;
+ struct inode *inode = path->dentry->d_inode;

- error = -EBADF;
- f = fget(dfd);
- if (!f)
- goto out;
- dentry = f->f_path.dentry;
- mnt = f->f_path.mnt;
- } else {
- error = __user_walk_fd(dfd, filename, (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW, &nd);
- if (error)
- goto out;
-
- dentry = nd.path.dentry;
- mnt = nd.path.mnt;
- }
-
- inode = dentry->d_inode;
-
- error = mnt_want_write(mnt);
+ error = mnt_want_write(path->mnt);
if (error)
- goto dput_and_out;
+ goto out;

if (times && times[0].tv_nsec == UTIME_NOW &&
times[1].tv_nsec == UTIME_NOW)
@@ -145,15 +106,70 @@ long do_utimes(int dfd, char __user *fil
}
}
mutex_lock(&inode->i_mutex);
- error = notify_change(dentry, &newattrs);
+ error = notify_change(path->dentry, &newattrs);
mutex_unlock(&inode->i_mutex);
+
mnt_drop_write_and_out:
- mnt_drop_write(mnt);
-dput_and_out:
- if (f)
- fput(f);
- else
+ mnt_drop_write(path->mnt);
+out:
+ 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, char __user *filename, struct timespec *times, int flags)
+{
+ int error = -EINVAL;
+
+ if (times && (!nsec_valid(times[0].tv_nsec) ||
+ !nsec_valid(times[1].tv_nsec))) {
+ goto out;
+ }
+
+ if (flags & ~AT_SYMLINK_NOFOLLOW)
+ goto out;
+
+ if (filename == NULL && dfd != AT_FDCWD) {
+ struct file *file;
+
+ if (flags & AT_SYMLINK_NOFOLLOW)
+ goto out;
+
+ file = fget(dfd);
+ error = -EBADF;
+ if (!file)
+ goto out;
+
+ error = utimes_common(&file->f_path, times);
+ fput(file);
+ } else {
+ struct nameidata nd;
+ int lookup_flags = 0;
+
+ if (!(flags & AT_SYMLINK_NOFOLLOW))
+ lookup_flags |= LOOKUP_FOLLOW;
+
+ error = __user_walk_fd(dfd, filename, lookup_flags, &nd);
+ if (error)
+ goto out;
+
+ error = utimes_common(&nd.path, times);
path_put(&nd.path);
+ }
+
out:
return error;
}

--
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