[Qemu-devel] [PATCH v3 0/9] VHDX log replay and write support

[Jeff Cody]

This patch series contains the initial VHDX log parsing, replay,
and write support.

=== v3 changes ===  

Thank you Kevin & Stefan for the feedback; incoporated in v3:

Patch 1: --- nil ---

Patch 2: * use sizeof(crc) instead of 4
         * remove outdated comment
         * use sizeof(MSGUID) instead of 16
         * direct assignment of guid structs rather than memcpy
         * rename 'rw' to 'generate_data_write_guid'
         * use offsetof() instead of 4
         * comment typos
         * add missing error checking
         * MSGUID is now QEMU_PACKED
         * configure enable for vhdx is now correct and not braindead

Patch 3: --- nil ---

Patch 4: * code style fixes
         * removed unused struct (VHDXLogEntryInfo)

Patch 5: * more direct assignment of guid rather than memcpy
         * order of operation in export/import the same now
         * became less generous with newlines (bah-humbug!)

Patch 6: * more direct assignment of guid rather than memcpy     
         * add error check in vhdx_user_visible_write(), now returns int

Patch 7: * check error return now of vhdx_user_visible_write()

Patch 8: * check error return now of vhdx_user_visible_write()
         * vhdx_log_write_sectors() uses bdrv_pwrite() vs bdrv_pwrite_sync()
         * more direct assignment of guid rather than memcpy     
         * use offsetof() instead of 4

Patch 9: --- nil ---

=== end v3 changelog ===

v2 changes:  Incorporated Fam's review feedback - Thank you Fam for the feedback

=== end v2 changelog ===

This will allow an existing log in a VHDX image to be replayed (e.g., a VHDX
image from a Hyper-V host that crashed).  In addition, metadata writes are
enabled through the log.  This allows write support to be enabled for VHDX,
as the BAT can be updated safely via the log journal.

These exact patches are available from github, for testing:
https://github.com/codyprime/qemu-kvm-jtc/tree/vhdx-write-v2-upstream

The latest vhdx work (including anything beyond these patches, such as
backing/parent file support) can be found at:
https://github.com/codyprime/qemu-kvm-jtc/tree/jtc-vhdx-latest

Jeff Cody (9):
  block: vhdx - minor comments and typo correction.
  block: vhdx - add header update capability.
  block: vhdx code movement - VHDXMetadataEntries and BDRVVHDXState to
    header.
  block: vhdx - log support struct and defines
  block: vhdx - break endian translation functions out
  block: vhdx - update log guid in header, and first write tracker
  block: vhdx - log parsing, replay, and flush support
  block: vhdx - add log write support
  block: vhdx write support

 block/Makefile.objs |    2 +-
 block/vhdx-endian.c |  141 +++++++
 block/vhdx-log.c    | 1011 +++++++++++++++++++++++++++++++++++++++++++++++++++
 block/vhdx.c        |  399 ++++++++++++++------
 block/vhdx.h        |  135 +++++--
 configure           |   24 ++
 6 files changed, 1585 insertions(+), 127 deletions(-)
 create mode 100644 block/vhdx-endian.c
 create mode 100644 block/vhdx-log.c

-- 
1.8.1.4