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

Orabug: 25547820

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.

Cc: stable@vger.kernel.org
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
(cherry picked from commit 117aceb030307dcd431fdcff87ce988d3016c34a)
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>

diff --git a/drivers/md/dm-era-target.c b/drivers/md/dm-era-target.c
index ad913cd4aded33206ce8b79bae7e13d8d593f2fb..330151d6ee4210352082fff9e4a2cf9a4c8f6636 100644 (file)
--- a/drivers/md/dm-era-target.c
+++ b/drivers/md/dm-era-target.c
@@ -957,15 +957,15 @@ static int metadata_commit(struct era_metadata *md)
                }
        }
 
-       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;
        }