Patch 2: The bdrv_is_allocated() functions may return a number of zero sectors e.g. if a sector beyond the image end has been queried. Respect this case in qemu-io's map implementation so it doesn't run into an infinite loop (https://bugs.launchpad.net/qemu/+bug/1356969).
Patch 1: In that bug report, bdrv_co_get_block_status() fell through to the underlying file to get additional information (whether the sectors are zeroed). However, the offset reported by the image format (qcow2) was beyond the size of the underlying file and so this second query returned only zero clusters which replaced the actual number of sectors queried in the "formatted" (on qcow2 level) image. This replacement is generally fine because it allows bdrv_co_get_block_status() to follow the granularity (holes and non-holes) of the underlying file, but not if only zero clusters could be queried (which indicates a request beyond the image end). This patch makes bdrv_co_get_block_status() respect the underlying file's EOF and act accordingly. But because errors from this second call are ignored, the number of sector queried successfully should be ignored as well, which makes qemu-io -c map actually work for that bug report. Patch 3 adds a test for patch 1; I could not conceive a test for patch 2 which patch 1 would not already catch, but patch 2 should be simple enough not to require a test anyway. v2: - In v1, patch 1 completely ignored the number of queried sectors returned by the recursive call; but it should only be ignored in case of EOF (which is indicated by returning 0 as the queried clusters count) - Thanks to fixing patch 1, the area queried in the test added in patch 3 is now marked unallocated (which is correct because it's beyond the EOF). Therefore, this test does no longer require _filter_qemu_img_map() (because there are no mappings shown) and this series no longer depends on the qemu-img/QMP commit series. Max Reitz (3): block: Respect underlying file's EOF qemu-io: Respect early image end for map iotests: Add test for map commands block.c | 16 ++++++++++-- qemu-io-cmds.c | 5 +++- tests/qemu-iotests/102 | 64 ++++++++++++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/102.out | 10 ++++++++ tests/qemu-iotests/group | 1 + 5 files changed, 93 insertions(+), 3 deletions(-) create mode 100755 tests/qemu-iotests/102 create mode 100644 tests/qemu-iotests/102.out -- 1.9.3
