[PATCH-SERIES v7 pve-storage/qemu-server] add external qcow2 snapshot support

[Alexandre Derumier]

This patch series implement qcow2 external snapshot support for files && lvm volumes

The current internal qcow2 snapshots have bad write performance because no metadatas can be preallocated.

This is particulary visible on a shared filesystem like ocfs2 or gfs2.

Also other bugs are freeze/lock reported by users since years on snapshots delete on nfs
(The disk access seem to be frozen during all the delete duration)

This also open doors for remote snapshot export-import for storage replication.

Changelog v7:
    - rebased on fiona blockdev work 

MAIN TODO:
    - add snapshots tests in both pve-storage && qemu-server
    - better handle snapshot failure with multiple disks

pve-storage:

Alexandre Derumier (10):
  tests: add lvmplugin test
  common: add qemu_img_create an preallocation_cmd_option
  common: qemu_img_create: add backing_file support
  rename_volume: add source && target snap
  common: add qemu_img_info helper
  common: add qemu-img measure
  storage: volume_snapshot: add $running param
  qcow2: add external snapshot support
  lvmplugin: add qcow2 snapshot
  storage : add volume_support_qemu_snapshot

 src/PVE/Storage.pm                   |  34 +-
 src/PVE/Storage/Common.pm            | 116 ++++++
 src/PVE/Storage/DirPlugin.pm         |  11 +
 src/PVE/Storage/ESXiPlugin.pm        |   2 +-
 src/PVE/Storage/ISCSIDirectPlugin.pm |   2 +-
 src/PVE/Storage/LVMPlugin.pm         | 519 ++++++++++++++++++++----
 src/PVE/Storage/LvmThinPlugin.pm     |   2 +-
 src/PVE/Storage/PBSPlugin.pm         |   2 +-
 src/PVE/Storage/Plugin.pm            | 376 ++++++++++++-----
 src/PVE/Storage/RBDPlugin.pm         |   8 +-
 src/PVE/Storage/ZFSPoolPlugin.pm     |   2 +-
 src/test/Makefile                    |   5 +-
 src/test/run_test_lvmplugin.pl       | 577 +++++++++++++++++++++++++++
 13 files changed, 1465 insertions(+), 191 deletions(-)
 create mode 100755 src/test/run_test_lvmplugin.pl

qemu-server:

Alexandre Derumier (3):
  qemu_img convert : add external snapshot support
  blockdev: add backing_chain support
  qcow2: add external snapshot support

 src/PVE/QemuConfig.pm                         |   4 +-
 src/PVE/QemuServer.pm                         | 132 +++++--
 src/PVE/QemuServer/Blockdev.pm                | 345 +++++++++++++++++-
 src/PVE/QemuServer/QemuImage.pm               |   6 +-
 src/test/cfg2cmd/simple-backingchain.conf     |  25 ++
 src/test/cfg2cmd/simple-backingchain.conf.cmd |  33 ++
 src/test/run_config2command_tests.pl          |  47 +++
 src/test/run_qemu_img_convert_tests.pl        |  59 +++
 src/test/snapshot-test.pm                     |   4 +-
 9 files changed, 620 insertions(+), 35 deletions(-)
 create mode 100644 src/test/cfg2cmd/simple-backingchain.conf
 create mode 100644 src/test/cfg2cmd/simple-backingchain.conf.cmd

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2.39.5