Messages in this thread Patch in this message | | | Date | Thu, 23 Oct 2008 21:34:27 -0700 | From | Greg KH <> | Subject | [patch 12/27] dm exception store: fix misordered writes |
| |
2.6.27-stable review patch. If anyone has any objections, please let us know.
------------------ From: Mikulas Patocka <mpatocka@redhat.com>
commit 7acedc5b98a2fcff64f00c21110aae7d3ac2f7df upstream
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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/md/dm-exception-store.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
--- a/drivers/md/dm-exception-store.c +++ b/drivers/md/dm-exception-store.c @@ -603,17 +603,22 @@ static void persistent_commit(struct exc 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); --
| |