Merge tag 'xfs-4.18-merge-10' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull more xfs updates from Darrick Wong:
 "Here's the second round of patches for XFS for 4.18. Most of the
  commits are small cleanups, bug fixes, and continued strengthening of
  metadata verifiers; the bulk of the diff is the conversion of the
  fs/xfs/ tree to use SPDX tags.

  This series has been run through a full xfstests run over the weekend
  and through a quick xfstests run against this morning's master, with
  no major failures reported.

  Summary:

   - Strengthen metadata checking to avoid ASSERTing on bad disk
     contents

   - Validate btree records that are being retrieved for clients

   - Strengthen root inode verification

   - Convert license blurbs to SPDX tags

   - Enable changing DAX flag on directories

   - Fix some writeback deadlocks in reflink

   - Refactor out some old xfs helpers

   - Move type verifiers to a separate file

   - Fix some fuzzer crashes

   - Various other bug fixes"

* tag 'xfs-4.18-merge-10' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (31 commits)
  xfs: update incore per-AG inode count
  xfs: replace do_mod with native operations
  xfs: don't call xfs_da_shrink_inode with NULL bp
  xfs: clean up MIN/MAX
  xfs: move various type verifiers to common file
  xfs: xfs_reflink_convert_cow() memory allocation deadlock
  xfs: setup VFS i_rwsem lockdep state correctly
  xfs: fix string handling in label get/set functions
  xfs: convert to SPDX license tags
  xfs: validate btree records on retrieval
  xfs: push corruption -> ESTALE conversion to xfs_nfs_get_inode()
  xfs: verify root inode more thoroughly
  xfs: verify COW extent size hint is valid in inode verifier
  xfs: verify extent size hint is valid in inode verifier
  xfs: catch bad stripe alignment configurations
  iomap: fsync swap files before iterating mappings
  xfs: use xfs_trans_getsb in xfs_sync_sb_buf
  xfs: don't assert on corrupted unlinked inode list
  xfs: explicitly pass buffer size to xfs_corruption_error
  xfs: don't assert when on-disk btree pointers are garbage
  ...

fs/xfs/xfs_ioctl.c

@@ -1,19 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
  * All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software Foundation,
- * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 #include "xfs.h"
 #include "xfs_fs.h"
@@ -1094,12 +1082,14 @@ xfs_ioctl_setattr_dax_invalidate(
 	/*
 	 * It is only valid to set the DAX flag on regular files and
 	 * directories on filesystems where the block size is equal to the page
-	 * size. On directories it serves as an inherit hint.
+	 * size. On directories it serves as an inherited hint so we don't
+	 * have to check the device for dax support or flush pagecache.
 	 */
 	if (fa->fsx_xflags & FS_XFLAG_DAX) {
 		if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
 			return -EINVAL;
-		if (!bdev_dax_supported(xfs_find_bdev_for_inode(VFS_I(ip)),
+		if (S_ISREG(inode->i_mode) &&
+		    !bdev_dax_supported(xfs_find_bdev_for_inode(VFS_I(ip)),
 				sb->s_blocksize))
 			return -EINVAL;
 	}
@@ -1110,6 +1100,9 @@ xfs_ioctl_setattr_dax_invalidate(
 	if (!(fa->fsx_xflags & FS_XFLAG_DAX) && !IS_DAX(inode))
 		return 0;
 
+	if (S_ISDIR(inode->i_mode))
+		return 0;
+
 	/* lock, flush and invalidate mapping in preparation for flag change */
 	xfs_ilock(ip, XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL);
 	error = filemap_write_and_wait(inode->i_mapping);
@@ -1819,13 +1812,13 @@ xfs_ioc_getlabel(
 	/* Paranoia */
 	BUILD_BUG_ON(sizeof(sbp->sb_fname) > FSLABEL_MAX);
 
+	/* 1 larger than sb_fname, so this ensures a trailing NUL char */
+	memset(label, 0, sizeof(label));
 	spin_lock(&mp->m_sb_lock);
-	strncpy(label, sbp->sb_fname, sizeof(sbp->sb_fname));
+	strncpy(label, sbp->sb_fname, XFSLABEL_MAX);
 	spin_unlock(&mp->m_sb_lock);
 
-	/* xfs on-disk label is 12 chars, be sure we send a null to user */
-	label[XFSLABEL_MAX] = '\0';
-	if (copy_to_user(user_label, label, sizeof(sbp->sb_fname)))
+	if (copy_to_user(user_label, label, sizeof(label)))
 		return -EFAULT;
 	return 0;
 }
@@ -1861,7 +1854,7 @@ xfs_ioc_setlabel(
 
 	spin_lock(&mp->m_sb_lock);
 	memset(sbp->sb_fname, 0, sizeof(sbp->sb_fname));
-	strncpy(sbp->sb_fname, label, sizeof(sbp->sb_fname));
+	memcpy(sbp->sb_fname, label, len);
 	spin_unlock(&mp->m_sb_lock);
 
 	/*