[PATCH v2] ceph: fix getxattr return values for vxattrs

We have several virtual xattrs in cephfs which return various values as strings. xattrs don't necessarily return strings however, so we need to include the terminating NULL byte when we return the length. Furthermore, the getxattr manpage says that we should return -ERANGE if the buffer is too small to hold the resulting value. Let's start doing that here as well. URL: https://bugzilla.redhat.com/show_bug.cgi?id=1717454 Reported-by: Tomas Petr &lt;tpetr(a)redhat.com&gt; Signed-off-by: Jeff Layton &lt;jlayton(a)kernel.org&gt; --- fs/ceph/xattr.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c index 6621d27e64f5..2a61e02e7166 100644 --- a/fs/ceph/xattr.c +++ b/fs/ceph/xattr.c @@ -803,8 +803,15 @@ ssize_t __ceph_getxattr(struct inode *inode, const char *name, void *value, if (err) return err; err = -ENODATA; - if (!(vxattr->exists_cb && !vxattr->exists_cb(ci))) - err = vxattr->getxattr_cb(ci, value, size); + if (!(vxattr->exists_cb && !vxattr->exists_cb(ci))) { + /* + * getxattr_cb returns strlen(value), xattr length must + * include the NULL. + */ + err = vxattr->getxattr_cb(ci, value, size) + 1; + if (size && size < err) + err = -ERANGE; + } return err; } -- 2.21.0