xfs: update lazy sb counters immediately for resizefs

sb_fdblocks will be updated lazily if lazysbcount is enabled,
therefore when shrinking the filesystem sb_fdblocks could be
larger than sb_dblocks and xfs_validate_sb_write() would fail.

Even for growfs case, it'd be better to update lazy sb counters
immediately to reflect the real sb counters.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/xfs_fsops.c

@@ -128,6 +128,15 @@ xfs_growfs_data_private(
 				 nb - mp->m_sb.sb_dblocks);
 	if (id.nfree)
 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree);
+
+	/*
+	 * Sync sb counters now to reflect the updated values. This is
+	 * particularly important for shrink because the write verifier
+	 * will fail if sb_fdblocks is ever larger than sb_dblocks.
+	 */
+	if (xfs_sb_version_haslazysbcount(&mp->m_sb))
+		xfs_log_sb(tp);
+
 	xfs_trans_set_sync(tp);
 	error = xfs_trans_commit(tp);
 	if (error)