namei: saner calling conventions for mountpoint_last() (ba8f4613) · Commits · 戴 / test

fs/namei.c

+25 −25

Original line number	Diff line number	Diff line
		@@ -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;
		}

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