[PATCH] xfs: allow SECURE namespace xattrs to use reserved pool

[Eric Sandeen <sandeen@redhat.com>]

We got a report from the podman folks that selinux relabels that happen
as part of their process were returning ENOSPC when the filesystem is
completely full. This is because xattr changes reserve about 15 blocks
for the worst case, but the common case is for selinux contexts to be
the sole, in-inode xattr and consume no blocks.

We already allow reserved space consumption for XFS_ATTR_ROOT for things
such as ACLs, and selinux / SECURE attributes are not so very different,
so allow them to use the reserved space as well.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index ab3d22f662f2..e59193609003 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -82,6 +82,7 @@ xfs_attr_change(
 {
 	struct xfs_mount	*mp = args->dp->i_mount;
 	int			error;
+	bool			rsvd;
 
 	if (xfs_is_shutdown(mp))
 		return -EIO;
@@ -110,7 +111,8 @@ xfs_attr_change(
 	args->whichfork = XFS_ATTR_FORK;
 	xfs_attr_sethash(args);
 
-	return xfs_attr_set(args, op, args->attr_filter & XFS_ATTR_ROOT);
+	rsvd = args->attr_filter & (XFS_ATTR_ROOT | XFS_ATTR_SECURE);
+	return xfs_attr_set(args, op, rsvd);
 }