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  1. 12 8月, 2010 1 次提交
  3. 17 2月, 2010 1 次提交
  5. 11 12月, 2009 5 次提交
  7. 17 10月, 2009 1 次提交
  9. 05 9月, 2009 3 次提交
    • M
      dm snapshot: fix on disk chunk size validation · ae0b7448
      由 Mikulas Patocka 提交于 
      Fix some problems seen in the chunk size processing when activating a
pre-existing snapshot.

For a new snapshot, the chunk size can either be supplied by the creator
or a default value can be used.  For an existing snapshot, the
chunk size in the snapshot header on disk should always be used.

If someone attempts to load an existing snapshot and has the 'default
chunk size' option set, the kernel uses its default value even when it
is incorrect for the snapshot being loaded.  This patch ensures the
correct on-disk value is always used.

Secondly, when the code does use the chunk size stored on the disk it is
prudent to revalidate it, so the code can exit cleanly if it got
corrupted as happened in
https://bugzilla.redhat.com/show_bug.cgi?id=461506 .

Cc: stable@kernel.org
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      ae0b7448
    • M
      dm snapshot: fix header corruption race on invalidation · 61578dcd
      由 Mikulas Patocka 提交于 
      If a persistent snapshot fills up, a race can corrupt the on-disk header
which causes a crash on any future attempt to activate the snapshot
(typically while booting).  This patch fixes the race.

When the snapshot overflows, __invalidate_snapshot is called, which calls
snapshot store method drop_snapshot. It goes to persistent_drop_snapshot that
calls write_header. write_header constructs the new header in the "area"
location.

Concurrently, an existing kcopyd job may finish, call copy_callback
and commit_exception method, that goes to persistent_commit_exception.
persistent_commit_exception doesn't do locking, relying on the fact that
callbacks are single-threaded, but it can race with snapshot invalidation and
overwrite the header that is just being written while the snapshot is being
invalidated.

The result of this race is a corrupted header being written that can
lead to a crash on further reactivation (if chunk_size is zero in the
corrupted header).

The fix is to use separate memory areas for each.

See the bug: https://bugzilla.redhat.com/show_bug.cgi?id=461506

Cc: stable@kernel.org
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      61578dcd
    • M
      dm snapshot: refactor zero_disk_area to use chunk_io · 02d2fd31
      由 Mikulas Patocka 提交于 
      Refactor chunk_io to prepare for the fix in the following patch.

Pass an area pointer to chunk_io and simplify zero_disk_area to use
chunk_io.  No functional change.

Cc: stable@kernel.org
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      02d2fd31
  11. 22 6月, 2009 1 次提交
  13. 23 5月, 2009 1 次提交
  15. 03 4月, 2009 7 次提交
  17. 06 1月, 2009 4 次提交
  19. 22 10月, 2008 3 次提交
  21. 10 10月, 2008 2 次提交
  23. 25 4月, 2008 3 次提交
  25. 08 2月, 2008 1 次提交
  27. 18 7月, 2007 1 次提交
  29. 13 7月, 2007 3 次提交
  31. 10 5月, 2007 1 次提交
  33. 03 10月, 2006 2 次提交