Patch "dm era: save spacemap metadata root after the pre-commit" has been added to the 4.9-stable tree

Patch "dm era: save spacemap metadata root after the pre-commit" has been added to the 4.9-stable tree

[gregkh]

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

    dm era: save spacemap metadata root after the pre-commit

to the 4.9-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:
     dm-era-save-spacemap-metadata-root-after-the-pre-commit.patch
and it can be found in the queue-4.9 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 117aceb030307dcd431fdcff87ce988d3016c34a Mon Sep 17 00:00:00 2001
From: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Date: Fri, 7 Apr 2017 12:14:55 -0700
Subject: dm era: save spacemap metadata root after the pre-commit

From: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>

commit 117aceb030307dcd431fdcff87ce988d3016c34a upstream.

When committing era metadata to disk, it doesn't always save the latest
spacemap metadata root in superblock. Due to this, metadata is getting
corrupted sometimes when reopening the device. The correct order of update
should be, pre-commit (shadows spacemap root), save the spacemap root
(newly shadowed block) to in-core superblock and then the final commit.

Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/dm-era-target.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/md/dm-era-target.c
+++ b/drivers/md/dm-era-target.c
@@ -961,15 +961,15 @@ static int metadata_commit(struct era_me
 		}
 	}
 
-	r = save_sm_root(md);
+	r = dm_tm_pre_commit(md->tm);
 	if (r) {
-		DMERR("%s: save_sm_root failed", __func__);
+		DMERR("%s: pre commit failed", __func__);
 		return r;
 	}
 
-	r = dm_tm_pre_commit(md->tm);
+	r = save_sm_root(md);
 	if (r) {
-		DMERR("%s: pre commit failed", __func__);
+		DMERR("%s: save_sm_root failed", __func__);
 		return r;
 	}
 


Patches currently in stable-queue which might be from somasundaram.krishnasamy@oracle.com are

queue-4.9/dm-era-save-spacemap-metadata-root-after-the-pre-commit.patch