[Qemu-devel] [PATCH v4 0/3] block: commits of snapshots larger than backing files

[Jeff Cody]

Changes, v3->v4

Patch 1/3: Commit message typo (Eric)
Patch 2/3: Removed dead code (Benoît)
Patch 3/3: None

Changes, v2->v3:

Patch 1/3: None
Patch 2/3: Set errp for both bdrv_getlength() failure cases (Fam)
           Remove "." from error message (Eric Blake)
Patch 3/3: Removed spurious double space (Eric Blake)


Changes, v1->v2:

Patch 1/3: Added error check for bdrv_getlength() return (Stefan)
Patch 2/3: Restore flags in commit_active_start() on failures after
           the bdrv_reopen() (Fam)
Patch 3/3: New patch, adds documentation clarification for the behavior
           of both offline commit, and live block commit, as it pertains
           to image truncation. (Stefan)

If a snapshot is larger than a backing file, then the offline bdrv_commit and
the live active layer commit will fail with an i/o error (usually).  A live
commit of a non-active layer will complete successfully, as it runs
bdrv_truncate() on the backing image to resize it to the larger size.

For both bdrv_commit() and commit_active_start(), this series will resize
the underlying base image if needed.  If the resize fails, an error will
be returned.


Jeff Cody (3):
  block: resize backing file image during offline commit, if necessary
  block: resize backing image during active layer commit, if needed
  block: update block commit documentation regarding image truncation

 block.c          | 23 ++++++++++++++++++++---
 block/mirror.c   | 38 ++++++++++++++++++++++++++++++++++++++
 hmp-commands.hx  |  5 +++++
 qapi-schema.json |  7 +++++++
 qemu-img.texi    |  7 ++++++-
 qmp-commands.hx  | 39 +++++++++++++++++++++++++++++++++++++++
 6 files changed, 115 insertions(+), 4 deletions(-)

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1.8.3.1