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(-) -- 1.8.3.1
