From fc46ff14390ec9ee346f58b33486ea23157d981f Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Thu, 12 Nov 2020 17:39:58 -0500
Subject: [PATCH] xfs: set xefi_discard when creating a deferred agfl free log
 intent item

Source kernel commit: 2c334e12f957cd8c6bb66b4aa3f79848b7c33cab

Make sure that we actually initialize xefi_discard when we're scheduling
a deferred free of an AGFL block.  This was (eventually) found by the
UBSAN while I was banging on realtime rmap problems, but it exists in
the upstream codebase.  While we're at it, rearrange the structure to
reduce the struct size from 64 to 56 bytes.

Fixes: fcb762f5de2e ("xfs: add bmapi nodiscard flag")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---
 libxfs/xfs_alloc.c | 1 +
 libxfs/xfs_bmap.h  | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/libxfs/xfs_alloc.c b/libxfs/xfs_alloc.c
index 93043d59..92f61fae 100644
--- a/libxfs/xfs_alloc.c
+++ b/libxfs/xfs_alloc.c
@@ -2463,6 +2463,7 @@ xfs_defer_agfl_block(
 	new->xefi_startblock = XFS_AGB_TO_FSB(mp, agno, agbno);
 	new->xefi_blockcount = 1;
 	new->xefi_oinfo = *oinfo;
+	new->xefi_skip_discard = false;
 
 	trace_xfs_agfl_free_defer(mp, agno, 0, agbno, 1);
 
diff --git a/libxfs/xfs_bmap.h b/libxfs/xfs_bmap.h
index e1bd484e..6747e97a 100644
--- a/libxfs/xfs_bmap.h
+++ b/libxfs/xfs_bmap.h
@@ -52,9 +52,9 @@ struct xfs_extent_free_item
 {
 	xfs_fsblock_t		xefi_startblock;/* starting fs block number */
 	xfs_extlen_t		xefi_blockcount;/* number of blocks in extent */
+	bool			xefi_skip_discard;
 	struct list_head	xefi_list;
 	struct xfs_owner_info	xefi_oinfo;	/* extent owner */
-	bool			xefi_skip_discard;
 };
 
 #define	XFS_BMAP_MAX_NMAP	4
-- 
2.27.0

