[Qemu-devel] [RFC PATCH v2 0/6] qemu-img: add preallocation=full

[Hu Tao]

This series implements full image preallocation to create a non-sparse image
file at creation time, both for raw and qcow2 format. The purpose is to avoid
performance deterioration of the guest cause by sparse image.

This series implements full preallocation by using 
fallocate()/posix_fallocate(),
which have the advantage that it is fast when creating large image file.
Zero-filling is not implemented, as writing zeros to image could be slow for 
large
file. (fallocate() ensures zero-filling, but posix_fallocate()) If users want 
it,
we can maybe add a option to let users have a choice. Suggestions?

Base on Kevin's patch at:
http://lists.gnu.org/archive/html/qemu-devel/2011-01/msg03017.html

Hu Tao (6):
  block: introduce prealloc_mode
  block: add BlockDriver.bdrv_preallocate.
  block/raw-posix: implement bdrv_preallocate
  raw-posix: Add full image preallocation option
  qcow2: implement bdrv_preallocate
  qcow2: Add full image preallocation option

 block.c                   | 13 +++++++++++
 block/qcow2.c             | 32 +++++++++++++++++++++------
 block/raw-posix.c         | 56 +++++++++++++++++++++++++++++++++++++++++++++++
 include/block/block.h     |  7 ++++++
 include/block/block_int.h |  3 +++
 5 files changed, 104 insertions(+), 7 deletions(-)

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1.8.3.1