[Qemu-devel] [PATCH v3 00/10] Clean up around bdrv_getlength()

[Markus Armbruster]

Issues addressed in this series:

* BlockDriver method bdrv_getlength() generally returns -errno, but
  some implementations return -1 instead.  Fix them [PATCH 1].

* Frequent conversions between sectors and bytes complicate the code
  needlessly.  Clean up some [PATCH 2-7].

* bdrv_getlength() always returns a multiple of BDRV_SECTOR_SIZE, but
  some places appear to be confused about that, and align the result
  up or down.  Don't [PATCH 8].

* bdrv_get_geometry() hides errors.  Don't use it in places where
  errors should be detected [PATCH 9+10].

Issues not addressed:

* We want to move away from counting in arbitrary units of 512 bytes
  we call "sector", even though it's not really related to either
  guest or host sector size.  My patches mostly move sideways:

  - Sector-based bdrv_get_geometry() gets partly replaced by new
    bdrv_nb_sectors(), still sector-based.

  - Some sector-based places get converted from bdrv_getlength() to
    bdrv_nb_sectors().  At least, this de-duplicates the conversion
    from bytes to sectors.

  - Two places get converted from bdrv_get_geometry() to
    bdrv_getlength().  Two baby steps forward.

* There are quite a few literals left in the code where
  BDRV_SECTOR_SIZE, BDRV_SECTOR_BITS or BDRV_SECTOR_MASK should be
  used instead.

* Error handling is missing in places, but it's not always obvious
  whether errors can actually happen, and if yes, how to handle them.

* Several calls of bdrv_get_geometry() remain in hw/.  I wanted to
  replace them all, but ran out of steam.

v3:
* Trivially rebased.
* Correct silly g_new() vs. g_new0() mistake in PATCH 09 [Max]

v2:
* Trivially rebased.
* Correct silly bdrv_getlength() vs. bdrv_nb_sectors() mistake in
  PATCH 03
* Split PATCH 03 into 03-07 [Kevin]
* Conversion of bs_sectors to array in PATCH 05 had a subscript off by
  one, fix [Kevin]
* Split PATCH 05 into 09-10 [Kevin]

Markus Armbruster (10):
  raw-posix: Fix raw_getlength() to always return -errno on error
  block: New bdrv_nb_sectors()
  block: Use bdrv_nb_sectors() in bdrv_make_zero()
  block: Use bdrv_nb_sectors() in bdrv_aligned_preadv()
  block: Use bdrv_nb_sectors() in bdrv_co_get_block_status()
  block: Use bdrv_nb_sectors() in img_convert()
  block: Use bdrv_nb_sectors() where sectors, not bytes are wanted
  block: Drop superfluous aligning of bdrv_getlength()'s value
  qemu-img: Make img_convert() get image size just once per image
  block: Avoid bdrv_get_geometry() where errors should be detected

 block-migration.c     |  9 +++--
 block.c               | 81 ++++++++++++++++++++++++--------------------
 block/qapi.c          | 14 +++++---
 block/qcow2.c         |  3 +-
 block/raw-posix.c     | 28 ++++++++++++----
 block/vmdk.c          |  5 ++-
 include/block/block.h |  1 +
 qemu-img.c            | 93 ++++++++++++++++++++++++++++++++++-----------------
 8 files changed, 147 insertions(+), 87 deletions(-)

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1.9.3