[PATCH v4 0/3] nbd: WRITE_ZEROES and a few fixes

[Wouter Verhelst <w@uter.be>]

Implement the WRITE_ZEROES command for the NBD kernel driver. While
here, add NBD_FLAG_ROTATIONAL to the function that decodes our flags for
debugfs.

---
v2: Divide UINT_MAX by blksize for the maximum number of sectors
supported by trim/discard and write_zeroes commands, as NBD uses 32-bit
values for byte lengths, and otherwise that wouldn't fit.
v3: Use the SECTOR_SHIFT value as a right-shift operand, rather than the
blksize value, to get the correct operand.
v4: Fix commit messages to use correct style. Thanks, Jens.
---
 drivers/block/nbd.c      |   12 +++++++++++-
 include/uapi/linux/nbd.h |    5 ++++-
 2 files changed, 15 insertions(+), 2 deletions(-)