raid5-cache fixes

Hi,

some fixes for raid5-cache.
patch 1, a small fix
patch 2-3, move reclaim teardown to quiesce handling and add trim support. I still need md_update_sb there and play the mddev_is_locked trick as the reconfig_mutex is already hold at md stop. The md_update_sb probably can move to md core later.
patch 4-6, add error handling. For patch 4, I still need the journal bit check in in md core, otherwise there is no way to prevent 'echo remove > rdev/state' to delete journal disk. For patch 6, I didn't change has_failed() yet. Handling assemble with miss/failed log disk is still on going.

Next step is to make assemble correct with miss/failed log disk. This will need kernel/utilities cooperation. Song and I are working on it.

Thanks,
Shaohua

Shaohua Li (6):
md: show journal for journal disk in disk state sysfs
raid5-cache: move reclaim stop to quiesce
raid5-cache: add trim support for log
md: don't export log device
md: set In_Sync for log disk
raid5-cache: IO error handling

 drivers/md/md.c          |  9 ++++--
 drivers/md/raid5-cache.c | 83 ++++++++++++++++++++++++++++++++++++++++--------
 drivers/md/raid5.c       |  7 +++-
 drivers/md/raid5.h       |  3 ++
 4 files changed, 85 insertions(+), 17 deletions(-)

2.4.6