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Commit 6d7b5aae authored by Al Viro's avatar Al Viro
Browse files

namei.c: let follow_link() do put_link() on failure 



no need for kludgy "set cookie to ERR_PTR(...) because we failed
before we did actual ->follow_link() and want to suppress put_link()",
no pointless check in put_link() itself.

Callers checked if follow_link() has failed anyway; might as well
break out of their loops if that happened, without bothering
to call put_link() first.

[AV: folded fixes from hch]

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 1d674107

fs/namei.c

+41 −33
Original line number Diff line number Diff line
@@ -605,7 +605,7 @@ static inline void path_to_nameidata(const struct path *path, 
static inline void put_link(struct nameidata *nd, struct path *link, void *cookie)

{

	struct inode *inode = link->dentry->d_inode;

	if (!IS_ERR(cookie) && inode->i_op->put_link)

	if (inode->i_op->put_link)

		inode->i_op->put_link(link->dentry, nd, cookie);

	path_put(link);

}
@@ -613,19 +613,19 @@ static inline void put_link(struct nameidata *nd, struct path *link, void *cooki 
static __always_inline int

follow_link(struct path *link, struct nameidata *nd, void **p)

{

	int error;

	struct dentry *dentry = link->dentry;

	int error;

	char *s;



	BUG_ON(nd->flags & LOOKUP_RCU);



	if (link->mnt == nd->path.mnt)

		mntget(link->mnt);



	if (unlikely(current->total_link_count >= 40)) {

		*p = ERR_PTR(-ELOOP); /* no ->put_link(), please */

		path_put(&nd->path);

		return -ELOOP;

	}

	error = -ELOOP;

	if (unlikely(current->total_link_count >= 40))

		goto out_put_nd_path;



	cond_resched();

	current->total_link_count++;
@@ -633,21 +633,20 @@ follow_link(struct path *link, struct nameidata *nd, void **p) 
	nd_set_link(nd, NULL);



	error = security_inode_follow_link(link->dentry, nd);

	if (error) {

		*p = ERR_PTR(error); /* no ->put_link(), please */

		path_put(&nd->path);

		return error;

	}

	if (error)

		goto out_put_nd_path;



	nd->last_type = LAST_BIND;

	*p = dentry->d_inode->i_op->follow_link(dentry, nd);

	error = PTR_ERR(*p);

	if (!IS_ERR(*p)) {

		char *s = nd_get_link(nd);

	if (IS_ERR(*p))

		goto out_put_link;



	error = 0;

		if (s)

	s = nd_get_link(nd);

	if (s) {

		error = __vfs_follow_link(nd, s);

		else if (nd->last_type == LAST_BIND) {

	} else if (nd->last_type == LAST_BIND) {

		nd->flags |= LOOKUP_JUMPED;

		nd->inode = nd->path.dentry->d_inode;

		if (nd->inode->i_op->follow_link) {
@@ -656,7 +655,15 @@ follow_link(struct path *link, struct nameidata *nd, void **p) 
			error = -ELOOP;

		}

	}

	}

	if (unlikely(error))

		put_link(nd, link, *p);



	return error;



out_put_nd_path:

	path_put(&nd->path);

out_put_link:

	path_put(link);

	return error;

}
@@ -1383,7 +1390,8 @@ static inline int nested_symlink(struct path *path, struct nameidata *nd) 
		void *cookie;



		res = follow_link(&link, nd, &cookie);

		if (!res)

		if (res)

			break;

		res = walk_component(nd, path, &nd->last,

				     nd->last_type, LOOKUP_FOLLOW);

		put_link(nd, &link, cookie);
@@ -1777,7 +1785,8 @@ static int path_lookupat(int dfd, const char *name, 
			struct path link = path;

			nd->flags |= LOOKUP_PARENT;

			err = follow_link(&link, nd, &cookie);

			if (!err)

			if (err)

				break;

			err = lookup_last(nd, &path);

			put_link(nd, &link, cookie);

		}
@@ -2475,8 +2484,7 @@ static struct file *path_openat(int dfd, const char *pathname, 
		nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);

		error = follow_link(&link, nd, &cookie);

		if (unlikely(error))

			filp = ERR_PTR(error);

		else

			goto out_filp;

		filp = do_last(nd, &path, op, pathname);

		put_link(nd, &link, cookie);

	}