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[0/4] block: Do not call BlockDriver.bdrv_make_empty() directly

Message ID 20200428132629.796753-1-mreitz@redhat.com
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Series block: Do not call BlockDriver.bdrv_make_empty() directly | expand

Message

Max Reitz April 28, 2020, 1:26 p.m. UTC 
Branch: https://github.com/XanClic/qemu.git fix-bdrv_make_empty-v1
Branch: https://git.xanclic.moe/XanClic/qemu.git fix-bdrv_make_empty-v1

Hi,

Right now, there is no centralized bdrv_make_empty() function.  Not only
is it bad style to call BlockDriver methods directly, it is also wrong,
unless the caller has a BdrvChild with BLK_PERM_WRITE taken.

This series fixes that.

Note that as far as I’m aware this series shouldn’t visibly fix anything
at this point; but “block: Introduce real BdrvChildRole”
(https://lists.nongnu.org/archive/html/qemu-block/2020-02/msg00737.html)
makes the iotest break when run with -o data_file=$SOMETHING, without
this series applied beforehand.  (That is because without that series,
external data files are treated much like metadata children, so the
format driver always takes the WRITE permission if the file is writable;
but after that series, it only does so when it itself has a parent
requestion the WRITE permission.)


Max Reitz (4):
  block: Add bdrv_make_empty()
  block: Use bdrv_make_empty() where possible
  block: Add blk_make_empty()
  block: Use blk_make_empty() after commits

 include/block/block.h          |  1 +
 include/sysemu/block-backend.h |  2 ++
 block.c                        | 23 +++++++++++++++++++++++
 block/block-backend.c          |  5 +++++
 block/commit.c                 |  8 +++++++-
 block/replication.c            |  6 ++----
 block/vvfat.c                  |  4 +---
 qemu-img.c                     | 19 ++++++++++++++-----
 8 files changed, 55 insertions(+), 13 deletions(-)