raid5: fix three bugs.

Patch0/1 resolve possible oops.
Patch2 resolve bug about call aync_xor.

Jianpeng Ma (3):
raid5: Add per-stripe lock on toread in func handle_failed_stripe.
raid5: fix possible oops in add_stripe_bio when enable pr_debug.
raid5: Fix to_read/to_write judgement.

 drivers/md/raid5.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

1.7.9.5