namei: saner calling conventions for mountpoint_last()
leave the result in nd->path, have caller do follow_mount() and
copy it to the final destination.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 85d2097..ab4cacc 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2561,7 +2561,6 @@ EXPORT_SYMBOL(user_path_at_empty);
/**
* mountpoint_last - look up last component for umount
* @nd: pathwalk nameidata - currently pointing at parent directory of "last"
- * @path: pointer to container for result
*
* This is a special lookup_last function just for umount. In this case, we
* need to resolve the path without doing any revalidation.
@@ -2574,23 +2573,20 @@ EXPORT_SYMBOL(user_path_at_empty);
*
* Returns:
* -error: if there was an error during lookup. This includes -ENOENT if the
- * lookup found a negative dentry. The nd->path reference will also be
- * put in this case.
+ * lookup found a negative dentry.
*
- * 0: if we successfully resolved nd->path and found it to not to be a
- * symlink that needs to be followed. "path" will also be populated.
- * The nd->path reference will also be put.
+ * 0: if we successfully resolved nd->last and found it to not to be a
+ * symlink that needs to be followed.
*
* 1: if we successfully resolved nd->last and found it to be a symlink
- * that needs to be followed. "path" will be populated with the path
- * to the link, and nd->path will *not* be put.
+ * that needs to be followed.
*/
static int
-mountpoint_last(struct nameidata *nd, struct path *path)
+mountpoint_last(struct nameidata *nd)
{
int error = 0;
- struct dentry *dentry;
struct dentry *dir = nd->path.dentry;
+ struct path path;
/* If we're in rcuwalk, drop out of it to handle last component */
if (nd->flags & LOOKUP_RCU) {
@@ -2604,36 +2600,34 @@ mountpoint_last(struct nameidata *nd, struct path *path)
error = handle_dots(nd, nd->last_type);
if (error)
return error;
- dentry = dget(nd->path.dentry);
+ path.dentry = dget(nd->path.dentry);
} else {
- dentry = d_lookup(dir, &nd->last);
- if (!dentry) {
+ path.dentry = d_lookup(dir, &nd->last);
+ if (!path.dentry) {
/*
* No cached dentry. Mounted dentries are pinned in the
* cache, so that means that this dentry is probably
* a symlink or the path doesn't actually point
* to a mounted dentry.
*/
- dentry = lookup_slow(&nd->last, dir,
+ path.dentry = lookup_slow(&nd->last, dir,
nd->flags | LOOKUP_NO_REVAL);
- if (IS_ERR(dentry))
- return PTR_ERR(dentry);
+ if (IS_ERR(path.dentry))
+ return PTR_ERR(path.dentry);
}
}
- if (d_is_negative(dentry)) {
- dput(dentry);
+ if (d_is_negative(path.dentry)) {
+ dput(path.dentry);
return -ENOENT;
}
if (nd->depth)
put_link(nd);
- path->dentry = dentry;
- path->mnt = nd->path.mnt;
- error = should_follow_link(nd, path, nd->flags & LOOKUP_FOLLOW,
- d_backing_inode(dentry), 0);
+ path.mnt = nd->path.mnt;
+ error = should_follow_link(nd, &path, nd->flags & LOOKUP_FOLLOW,
+ d_backing_inode(path.dentry), 0);
if (unlikely(error))
return error;
- mntget(path->mnt);
- follow_mount(path);
+ path_to_nameidata(&path, nd);
return 0;
}
@@ -2654,13 +2648,19 @@ path_mountpoint(struct nameidata *nd, unsigned flags, struct path *path)
if (IS_ERR(s))
return PTR_ERR(s);
while (!(err = link_path_walk(s, nd)) &&
- (err = mountpoint_last(nd, path)) > 0) {
+ (err = mountpoint_last(nd)) > 0) {
s = trailing_symlink(nd);
if (IS_ERR(s)) {
err = PTR_ERR(s);
break;
}
}
+ if (!err) {
+ *path = nd->path;
+ nd->path.mnt = NULL;
+ nd->path.dentry = NULL;
+ follow_mount(path);
+ }
terminate_walk(nd);
return err;
}