Commit 8bc0095d authored by Christian Brauner's avatar Christian Brauner Committed by Miklos Szeredi
Browse files

ovl: handle idmappings in ovl_xattr_{g,s}et() 



When retrieving xattrs from the upper or lower layers take the relevant
mount's idmapping into account. We rely on the previously introduced
ovl_i_path_real() helper to retrieve the relevant path. This is needed
to support idmapped base layers with overlay.

Cc: <linux-unionfs@vger.kernel.org>
Tested-by: default avatarGiuseppe Scrivano <gscrivan@redhat.com>
Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 8423b3bd

fs/overlayfs/inode.c

+6 −4
Original line number Diff line number Diff line
@@ -349,6 +349,7 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, 
	struct ovl_fs *ofs = OVL_FS(dentry->d_sb);

	struct dentry *upperdentry = ovl_i_dentry_upper(inode);

	struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry);

	struct path realpath;

	const struct cred *old_cred;



	err = ovl_want_write(dentry);
@@ -356,8 +357,9 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, 
		goto out;



	if (!value && !upperdentry) {

		ovl_path_lower(dentry, &realpath);

		old_cred = ovl_override_creds(dentry->d_sb);

		err = vfs_getxattr(&init_user_ns, realdentry, name, NULL, 0);

		err = vfs_getxattr(mnt_user_ns(realpath.mnt), realdentry, name, NULL, 0);

		revert_creds(old_cred);

		if (err < 0)

			goto out_drop_write;
@@ -395,11 +397,11 @@ int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, 
{

	ssize_t res;

	const struct cred *old_cred;

	struct dentry *realdentry =

		ovl_i_dentry_upper(inode) ?: ovl_dentry_lower(dentry);

	struct path realpath;



	ovl_i_path_real(inode, &realpath);

	old_cred = ovl_override_creds(dentry->d_sb);

	res = vfs_getxattr(&init_user_ns, realdentry, name, value, size);

	res = vfs_getxattr(mnt_user_ns(realpath.mnt), realpath.dentry, name, value, size);

	revert_creds(old_cred);

	return res;

}