Commit d45ea867 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Al Viro
Browse files

vfs: make follow_link check RCU safe 



This will allow this code to be used in RCU mode.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent decf3400

fs/namei.c

+10 −2
Original line number Diff line number Diff line
@@ -2201,6 +2201,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path, 
	int acc_mode = op->acc_mode;

	struct file *filp;

	struct inode *inode;

	int symlink_ok = 0;

	int error;



	nd->flags &= ~LOOKUP_PARENT;
@@ -2232,7 +2233,6 @@ static struct file *do_last(struct nameidata *nd, struct path *path, 
	}



	if (!(open_flag & O_CREAT)) {

		int symlink_ok = 0;

		if (nd->last.name[nd->last.len])

			nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;

		if (open_flag & O_PATH && !(nd->flags & LOOKUP_FOLLOW))
@@ -2364,8 +2364,16 @@ static struct file *do_last(struct nameidata *nd, struct path *path, 
	if (!inode)

		goto exit_dput;



	if (inode->i_op->follow_link)

	if (should_follow_link(inode, !symlink_ok)) {

		if (nd->flags & LOOKUP_RCU) {

			if (unlikely(unlazy_walk(nd, path->dentry))) {

				error = -ECHILD;

				goto exit;

			}

		}

		BUG_ON(inode != path->dentry->d_inode);

		return NULL;

	}



	path_to_nameidata(path, nd);

	nd->inode = inode;