Commit 6e45906a authored by Chuck Lever's avatar Chuck Lever
Browse files

NFSD: Return NFS4ERR_FILE_OPEN only when linking an open file 



RFC 8881 Section 18.9.4 paragraphs 1 - 2 tell us that RENAME should
return NFS4ERR_FILE_OPEN only when the target object is a file that
is currently open. If the target is a directory, some other status
must be returned.

The VFS is unlikely to return -EBUSY, but NFSD has to ensure that
errno does not leak to clients as a status code that is not
permitted by spec.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 3b60984e

fs/nfsd/vfs.c

+31 −13
Original line number Diff line number Diff line
@@ -1698,9 +1698,17 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	return err;

}



/*

 * Create a hardlink

 * N.B. After this call _both_ ffhp and tfhp need an fh_put

/**

 * nfsd_link - create a link

 * @rqstp: RPC transaction context

 * @ffhp: the file handle of the directory where the new link is to be created

 * @name: the filename of the new link

 * @len: the length of @name in octets

 * @tfhp: the file handle of an existing file object

 *

 * After this call _both_ ffhp and tfhp need an fh_put.

 *

 * Returns a generic NFS status code in network byte-order.

 */

__be32

nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
@@ -1708,6 +1716,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 
{

	struct dentry	*ddir, *dnew, *dold;

	struct inode	*dirp;

	int		type;

	__be32		err;

	int		host_err;
@@ -1727,11 +1736,11 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 
	if (isdotent(name, len))

		goto out;



	err = nfs_ok;

	type = d_inode(tfhp->fh_dentry)->i_mode & S_IFMT;

	host_err = fh_want_write(tfhp);

	if (host_err) {

		err = nfserrno(host_err);

	if (host_err)

		goto out;

	}



	ddir = ffhp->fh_dentry;

	dirp = d_inode(ddir);
@@ -1739,7 +1748,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 


	dnew = lookup_one_len(name, ddir, len);

	if (IS_ERR(dnew)) {

		err = nfserrno(PTR_ERR(dnew));

		host_err = PTR_ERR(dnew);

		goto out_unlock;

	}
@@ -1755,17 +1764,26 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 
	fh_fill_post_attrs(ffhp);

	inode_unlock(dirp);

	if (!host_err) {

		err = nfserrno(commit_metadata(ffhp));

		if (!err)

			err = nfserrno(commit_metadata(tfhp));

	} else {

		err = nfserrno(host_err);

		host_err = commit_metadata(ffhp);

		if (!host_err)

			host_err = commit_metadata(tfhp);

	}



	dput(dnew);

out_drop_write:

	fh_drop_write(tfhp);

	if (host_err == -EBUSY) {

		/*

		 * See RFC 8881 Section 18.9.4 para 1-2: NFSv4 LINK

		 * wants a status unique to the object type.

		 */

		if (type != S_IFDIR)

			err = nfserr_file_open;

		else

			err = nfserr_acces;

	}

out:

	return err;

	return err != nfs_ok ? err : nfserrno(host_err);



out_dput:

	dput(dnew);