Merge tag 'ovl-fixes-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs fixes from Miklos Szeredi:

 - Fix capability conversion and minor overlayfs bugs that are related
   to the unprivileged overlay mounts introduced in this cycle.

 - Fix two recent (v5.10) and one old (v4.10) bug.

 - Clean up security xattr copy-up (related to a SELinux regression).

* tag 'ovl-fixes-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: implement volatile-specific fsync error behaviour
  ovl: skip getxattr of security labels
  ovl: fix dentry leak in ovl_get_redirect
  ovl: avoid deadlock on directory ioctl
  cap: fix conversions on getxattr
  ovl: perform vfs_getxattr() with mounter creds
  ovl: add warning on user_ns mismatch

1 files changed, 27 insertions, 0 deletions

diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 6569031af3cd..9826b003f1d2 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -962,3 +962,30 @@ err_free:
 	kfree(buf);
 	return ERR_PTR(res);
 }
+
+/*
+ * ovl_sync_status() - Check fs sync status for volatile mounts
+ *
+ * Returns 1 if this is not a volatile mount and a real sync is required.
+ *
+ * Returns 0 if syncing can be skipped because mount is volatile, and no errors
+ * have occurred on the upperdir since the mount.
+ *
+ * Returns -errno if it is a volatile mount, and the error that occurred since
+ * the last mount. If the error code changes, it'll return the latest error
+ * code.
+ */
+
+int ovl_sync_status(struct ovl_fs *ofs)
+{
+	struct vfsmount *mnt;
+
+	if (ovl_should_sync(ofs))
+		return 1;
+
+	mnt = ovl_upper_mnt(ofs);
+	if (!mnt)
+		return 0;
+
+	return errseq_check(&mnt->mnt_sb->s_wb_err, ofs->errseq);
+}