Re: [Qemu-devel] [PATCH v3 for-2.11 0/4] Fix segfault in blockjob race condition

[Jeff Cody <jcody@redhat.com>]

On Tue, Nov 21, 2017 at 10:38:49AM -0500, Jeff Cody wrote:
> Changes from v2 -> v3:
> -----------------------
> 
> Patch 1: Updated commit message to include why immediate cancel is
>          ok to remove (Thanks Paolo)
> 
>          Dropped useless hunk (Thanks Stefan)
> 
> 
> Patch 2: Use correct atomic primitives, and document implicit
>          assumptions (Thanks Stefan, Paolo)
> 
>         Fix spelling in commit message (Thanks Eric)
> 
> Patch 3/4: Unchanged.
> 
> 
> Changes from v1 -> v2:
> -----------------------
> 
> Patch 1: Updated docs in blockjob_int.h (Thanks Stefan)
> 
> Patch 2/3: Squashed, and used const char * to hold the __func__ name of
>            the original scheduler (Thanks Paolo)
> 
> Patch 4: Unchanged.
> 
> Patch 5: Dropped qcow format for the test, it was so slow the test times
>          out, and it doesn't add any new dimension to the test.
> 
> 
> # git-backport-diff -r qemu/master.. -u github/bz1508708
> 
> 001/4:[0003] [FC] 'blockjob: do not allow coroutine double entry or entry-after-completion'
> 002/4:[down] 'coroutine: abort if we try to schedule or enter a pending coroutine'
> 003/4:[----] [--] 'qemu-iotests: add option in common.qemu for mismatch only'
> 004/4:[0002] [FC] 'qemu-iotest: add test for blockjob coroutine race condition'
> 
> 
> This series fixes a race condition segfault when using iothreads with
> blockjobs.
> 
> The qemu iotest in this series is a reproducer, as is the reproducer
> script attached in this bug report:
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=1508708
> 
> There are two additional patches to try and catch this sort of scenario
> with an abort, before a segfault or memory corruption occurs.
> 
> 
> Jeff Cody (4):
>   blockjob: do not allow coroutine double entry or
>     entry-after-completion
>   coroutine: abort if we try to schedule or enter a pending coroutine
>   qemu-iotests: add option in common.qemu for mismatch only
>   qemu-iotest: add test for blockjob coroutine race condition
> 
>  blockjob.c                     |  7 ++-
>  include/block/blockjob_int.h   |  3 +-
>  include/qemu/coroutine_int.h   |  6 +++
>  tests/qemu-iotests/200         | 99 ++++++++++++++++++++++++++++++++++++++++++
>  tests/qemu-iotests/200.out     | 14 ++++++
>  tests/qemu-iotests/common.qemu |  8 +++-
>  tests/qemu-iotests/group       |  1 +
>  util/async.c                   | 13 ++++++
>  util/qemu-coroutine-sleep.c    | 12 +++++
>  util/qemu-coroutine.c          | 13 ++++++
>  10 files changed, 172 insertions(+), 4 deletions(-)
>  create mode 100755 tests/qemu-iotests/200
>  create mode 100644 tests/qemu-iotests/200.out
> 
> -- 
> 2.9.5
> 


Thanks,

Made the change suggested by Stefan and Paolo.

Applied to my block branch:

git://github.com/codyprime/qemu-kvm-jtc block

-Jeff