Patch "gfs2: Fixes to "Implement iomap for block_map" (2)" has been added to the 4.15-stable tree

Patch "gfs2: Fixes to "Implement iomap for block_map" (2)" has been added to the 4.15-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    gfs2: Fixes to "Implement iomap for block_map" (2)

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     gfs2-fixes-to-implement-iomap-for-block_map-2.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 3b5da96e4585a2788da6a07619bda3518d76eb30 Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Mon, 5 Mar 2018 06:18:25 -0700
Subject: gfs2: Fixes to "Implement iomap for block_map" (2)

From: Andreas Gruenbacher <agruenba@redhat.com>

commit 3b5da96e4585a2788da6a07619bda3518d76eb30 upstream.

It turns out that commit 3229c18c0d6b2 'Fixes to "Implement iomap for
block_map"' introduced another bug in gfs2_iomap_begin that can cause
gfs2_block_map to set bh->b_size of an actual buffer to 0.  This can
lead to arbitrary incorrect behavior including crashes or disk
corruption.  Revert the incorrect part of that commit.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/gfs2/bmap.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -811,9 +811,6 @@ do_alloc:
 			iomap->length = hole_size(inode, lblock, &mp);
 		else
 			iomap->length = size - pos;
-	} else {
-		if (height <= ip->i_height)
-			iomap->length = hole_size(inode, lblock, &mp);
 	}
 	goto out_release;
 }


Patches currently in stable-queue which might be from agruenba@redhat.com are

queue-4.15/gfs2-clean-up-lookup-fillup-_metapath.patch
queue-4.15/gfs2-fixes-to-implement-iomap-for-block_map-2.patch