block: T10/DIF Fixes and cleanups v5

To: Jens Axboe <axboe@xxxxxxxxx>
Subject: block: T10/DIF Fixes and cleanups v5
From: Christoph Hellwig <hch@xxxxxx>
Date: Thu, 29 Jun 2017 11:31:07 -0700
Cc: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>, "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>, Shaohua Li <shli@xxxxxxxxxx>, linux-fsdevel@xxxxxxxxxxxxxxx, linux-block@xxxxxxxxxxxxxxx

This series contains a rebase of the DIF fixes from Dmitry, plus
a new patch from me to free the integrity data from bio_endio.

Follow-Ups:
- [PATCH 9/9] bio-integrity: stop abusing bi_end_io
  - From: Christoph Hellwig
- [PATCH 4/9] bio-integrity: fold bio_integrity_enabled to bio_integrity_prep
  - From: Christoph Hellwig
- [PATCH 5/9] t10-pi: Move opencoded contants to common header
  - From: Christoph Hellwig
- [PATCH 1/9] bio-integrity: bio_trim should truncate integrity vector accordingly
  - From: Christoph Hellwig
- [PATCH 7/9] bio: add bvec_iter rewind API
  - From: Christoph Hellwig
- [PATCH 6/9] block: guard bvec iteration logic
  - From: Christoph Hellwig
- [PATCH 3/9] bio-integrity: fix interface for bio_integrity_trim
  - From: Christoph Hellwig
- [PATCH 2/9] bio-integrity: bio_integrity_advance must update integrity seed
  - From: Christoph Hellwig
- [PATCH 8/9] bio-integrity: Restore original iterator on verify stage
  - From: Christoph Hellwig