There are patches floating around to add NBD_CMD_BLOCK_STATUS, but NBD wants to report status on byte granularity (even if the reporting will probably be naturally aligned to sectors or even much higher levels). I've therefore started the task of converting our block status code to report at a byte granularity rather than sectors.
The overall conversion currently looks like: part 1: bdrv_is_allocated (v3 is reviewed [1], modulo vvfat whitespace changes) part 2: dirty-bitmap (v4 is posted [2]; v2 was reviewed but rebase changes mean more review is needed) part 3: this series, for bdrv_get_block_status (first half of v1, at [3], did not get much review) part 4: upcoming series, for .bdrv_co_block_status (second half of v1 [3]) Available as a tag at: git fetch git://repo.or.cz/qemu/ericb.git nbd-byte-status-v2 It is based on the union of Max's and Kevin's block branches, plus posted fixes that make iotest 55 pass. The diffstat shows a net growth in line count, but some of that is due to better comments, and some because the code is a bit longer in order to handle differing alignments between caller and driver. I still haven't felt like tackling the task of rewriting migration/block.c and qemu-img.c to use bytes (instead of sectors) everywhere - that might give another net win in lines of code and legibility. Patch 1/15 isn't really mine; Manos will probably be posting a v3 of his series, which should be committed before mine [4]. [1] https://lists.gnu.org/archive/html/qemu-devel/2017-06/msg06077.html [2] https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg00269.html [3] https://lists.gnu.org/archive/html/qemu-devel/2017-04/msg02642.html [4] https://lists.gnu.org/archive/html/qemu-devel/2017-06/msg06846.html Since v1: rebase against lots of upstream churn; add patches to support arbitrary alignments and test them. I also split the original v1 series (31 patches) into two halves, where teaching the individual drivers about byte-level granularity is now going to be a fourth series (I'll post a 16/15 RFC patch to show the interface that will use) 001/15:[down] 'block: add default implementations for bdrv_co_get_block_status()' 002/15:[down] 'block: Allow NULL file for bdrv_get_block_status()' 003/15:[down] 'block: Add flag to avoid wasted work in bdrv_is_allocated()' 004/15:[0002] [FC] 'block: Make bdrv_round_to_clusters() signature more useful' 005/15:[0018] [FC] 'qcow2: Switch is_zero_sectors() to byte-based' 006/15:[0004] [FC] 'block: Switch bdrv_make_zero() to byte-based' 007/15:[----] [--] 'qemu-img: Switch get_block_status() to byte-based' 008/15:[0058] [FC] 'block: Convert bdrv_get_block_status() to bytes' 009/15:[0064] [FC] 'block: Switch bdrv_co_get_block_status() to byte-based' 010/15:[0001] [FC] 'block: Switch BdrvCoGetBlockStatusData to byte-based' 011/15:[down] 'block: Switch bdrv_common_block_status_above() to byte-based' 012/15:[0010] [FC] 'block: Switch bdrv_co_get_block_status_above() to byte-based' 013/15:[0063] [FC] 'block: Convert bdrv_get_block_status_above() to bytes' 014/15:[down] 'block: Align block status requests' 015/15:[down] 'qemu-io: Relax 'alloc' now that block-status doesn't assert' Eric Blake (14): block: Allow NULL file for bdrv_get_block_status() block: Add flag to avoid wasted work in bdrv_is_allocated() block: Make bdrv_round_to_clusters() signature more useful qcow2: Switch is_zero_sectors() to byte-based block: Switch bdrv_make_zero() to byte-based qemu-img: Switch get_block_status() to byte-based block: Convert bdrv_get_block_status() to bytes block: Switch bdrv_co_get_block_status() to byte-based block: Switch BdrvCoGetBlockStatusData to byte-based block: Switch bdrv_common_block_status_above() to byte-based block: Switch bdrv_co_get_block_status_above() to byte-based block: Convert bdrv_get_block_status_above() to bytes block: Align block status requests qemu-io: Relax 'alloc' now that block-status doesn't assert Manos Pitsidianakis (1): block: add default implementations for bdrv_co_get_block_status() include/block/block.h | 26 ++-- include/block/block_int.h | 27 +++- block/blkdebug.c | 9 +- block/commit.c | 12 +- block/io.c | 302 ++++++++++++++++++++++++++++----------------- block/mirror.c | 32 ++--- block/qcow2-cluster.c | 2 +- block/qcow2.c | 34 ++--- qemu-img.c | 71 ++++++----- qemu-io-cmds.c | 13 -- block/trace-events | 2 +- tests/qemu-iotests/177 | 11 +- tests/qemu-iotests/177.out | 18 ++- 13 files changed, 317 insertions(+), 242 deletions(-) -- 2.9.4
