diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2008-10-21 18:44:56 +0200 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2008-10-21 18:44:56 +0200 |
| commit | 7acedc5b98a2fcff64f00c21110aae7d3ac2f7df (patch) | |
| tree | ed9eda05b30d3606f1ad16e368c313b40c616c3d | |
| parent | dm exception store: refactor zero_area (diff) | |
| download | linux-7acedc5b98a2fcff64f00c21110aae7d3ac2f7df.tar.xz linux-7acedc5b98a2fcff64f00c21110aae7d3ac2f7df.zip | |
dm exception store: fix misordered writes
We must zero the next chunk on disk *before* writing out the current chunk, not
after. Otherwise if the machine crashes at the wrong time, the "end of metadata"
marker may be missing.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
| -rw-r--r-- | drivers/md/dm-exception-store.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c index fe6cef8df203..6179bf70f98a 100644 --- a/drivers/md/dm-exception-store.c +++ b/drivers/md/dm-exception-store.c @@ -611,17 +611,22 @@ static void persistent_commit(struct exception_store *store, return; /* + * If we completely filled the current area, then wipe the next one. + */ + if ((ps->current_committed == ps->exceptions_per_area) && + zero_disk_area(ps, ps->current_area + 1)) + ps->valid = 0; + + /* * Commit exceptions to disk. */ - if (area_io(ps, WRITE)) + if (ps->valid && area_io(ps, WRITE)) ps->valid = 0; /* * Advance to the next area if this one is full. */ if (ps->current_committed == ps->exceptions_per_area) { - if (zero_disk_area(ps, ps->current_area + 1)) - ps->valid = 0; ps->current_committed = 0; ps->current_area++; zero_memory_area(ps); |