From: Eric Sandeen <sandeen@redhat.com>
Date: Thu, 17 May 2018 17:00:06 +0000 (-0500)
Subject: xfs: set format back to extents if xfs_bmap_extents_to_btree
X-Git-Tag: v4.17.0-rc1~43^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7c4d311d7ed1ebdfa09b33c279e98e10a70575bb;p=thirdparty%2Fxfsprogs-dev.git

xfs: set format back to extents if xfs_bmap_extents_to_btree

Source kernel commit: 2c4306f719b083d17df2963bc761777576b8ad1b

If xfs_bmap_extents_to_btree fails in a mode where we call
xfs_iroot_realloc(-1) to de-allocate the root, set the
format back to extents.

Otherwise we can assume we can dereference ifp->if_broot
based on the XFS_DINODE_FMT_BTREE format, and crash.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199423
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---

diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c
index cc1bcb16f..5b4f8c245 100644
--- a/libxfs/xfs_bmap.c
+++ b/libxfs/xfs_bmap.c
@@ -716,12 +716,16 @@ xfs_bmap_extents_to_btree(
 	*logflagsp = 0;
 	if ((error = xfs_alloc_vextent(&args))) {
 		xfs_iroot_realloc(ip, -1, whichfork);
+		ASSERT(ifp->if_broot == NULL);
+		XFS_IFORK_FMT_SET(ip, whichfork, XFS_DINODE_FMT_EXTENTS);
 		xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
 		return error;
 	}
 
 	if (WARN_ON_ONCE(args.fsbno == NULLFSBLOCK)) {
 		xfs_iroot_realloc(ip, -1, whichfork);
+		ASSERT(ifp->if_broot == NULL);
+		XFS_IFORK_FMT_SET(ip, whichfork, XFS_DINODE_FMT_EXTENTS);
 		xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
 		return -ENOSPC;
 	}