Hi, v1 with detailed reasoning: https://lists.nongnu.org/archive/html/qemu-block/2022-02/msg00508.html
This series makes bdrv_refresh_limits() non-recursive so that it is sufficient for callers to ensure that the node on which they call it will not receive concurrent I/O requests (instead of ensuring the same for the whole subtree). We need to ensure such I/O does not happen because bdrv_refresh_limits() is not atomic and will produce intermediate invalid values, which will break concurrent I/O requests that read these values. v2: - Use separate `try` block to clean up in patch 2 instead of putting the `os.remove()` in the existing one (which would cause the second `os.remove()` to be skipped if the first one failed) git-backport-diff against v1: Key: [----] : patches are identical [####] : number of functional differences between upstream/downstream patch [down] : patch is downstream-only The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively 001/3:[----] [--] 'block: Make bdrv_refresh_limits() non-recursive' 002/3:[0005] [FC] 'iotests: Allow using QMP with the QSD' 003/3:[----] [--] 'iotests/graph-changes-while-io: New test' Hanna Reitz (3): block: Make bdrv_refresh_limits() non-recursive iotests: Allow using QMP with the QSD iotests/graph-changes-while-io: New test block/io.c | 4 - tests/qemu-iotests/iotests.py | 32 ++++++- .../qemu-iotests/tests/graph-changes-while-io | 91 +++++++++++++++++++ .../tests/graph-changes-while-io.out | 5 + 4 files changed, 127 insertions(+), 5 deletions(-) create mode 100755 tests/qemu-iotests/tests/graph-changes-while-io create mode 100644 tests/qemu-iotests/tests/graph-changes-while-io.out -- 2.34.1
