[patch 2/4] vfs: utimes cleanup

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

CC: Ulrich Drepper <drepper@redhat.com>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Miklos Szeredi 2008-07-01 15:01:27 +02:00 committed by Al Viro
parent 9767d74957
commit e9b76fedc6

View file

@ -48,54 +48,15 @@ static bool nsec_valid(long nsec)
return nsec >= 0 && nsec <= 999999999; return nsec >= 0 && nsec <= 999999999;
} }
/* If times==NULL, set access and modification to current time, static int utimes_common(struct path *path, struct timespec *times)
* 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; int error;
struct nameidata nd;
struct dentry *dentry;
struct inode *inode;
struct iattr newattrs; struct iattr newattrs;
struct file *f = NULL; struct inode *inode = path->dentry->d_inode;
struct vfsmount *mnt;
error = -EINVAL; error = mnt_want_write(path->mnt);
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;
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);
if (error) if (error)
goto dput_and_out; goto out;
if (times && times[0].tv_nsec == UTIME_NOW && if (times && times[0].tv_nsec == UTIME_NOW &&
times[1].tv_nsec == UTIME_NOW) times[1].tv_nsec == UTIME_NOW)
@ -145,15 +106,70 @@ long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags
} }
} }
mutex_lock(&inode->i_mutex); mutex_lock(&inode->i_mutex);
error = notify_change(dentry, &newattrs); error = notify_change(path->dentry, &newattrs);
mutex_unlock(&inode->i_mutex); mutex_unlock(&inode->i_mutex);
mnt_drop_write_and_out: mnt_drop_write_and_out:
mnt_drop_write(mnt); mnt_drop_write(path->mnt);
dput_and_out: out:
if (f) return error;
fput(f); }
else
/*
* 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); path_put(&nd.path);
}
out: out:
return error; return error;
} }