Preamble: This series is based on a combination of my (current) block branch and “iotests: Minor fixes”. I’ve pushed it here:
https://git.xanclic.moe/XanClic/qemu fuse-exports-v1 (The base is on fuse-exports-v1-base.) Hi, Ever since I found out that you can mount FUSE filesystems on regular files (not just directories), I had the idea of adding FUSE block exports to qemu where you can export block nodes as raw images. The best thing is that you’d be able to mount an image on itself, so whatever format it may be in, qemu lets it appear as a raw image (and you can then use regular tools like dd on it). I started with some concept of a qemu-blkfuse daemon (similar to qemu-nbd), but never sent patches, for two reasons: (1) Performance was not good, (2) it didn’t seem right, for some reason. Now Kevin is proposing a storage daemon for multiple export types like NBD, and he also mentioned FUSE (while knowing of my previous attempts). Now it does seem right to add FUSE exports to qemu, but only in the form of some module with a proper QAPI/QMP binding. Performance is still quite bad, but who cares. We can always improve it, if the need arises. This series does the following: First, add the FUSE export module (block/fuse.c) that implements the basic file access functions. (Note that you need libfuse 3.8.0 or later for SEEK_HOLE/SEEK_DATA.) Second, it allows using FUSE exports as a protocol in the iotests and makes many iotests work with it. (The file node is exported by a background qemu instance to $SOCK_DIR.) Note that I only ran raw and qcow2 on it; I’m sure other formats currently have some failing tests. This gives us a lot of coverage for, well, not free (it does take ten patches), but for cheap; but there are still some more specialized things we want to test, so third and last, this series adds an iotest dedicated to FUSE exports. Final rather important notice: I didn’t really run the iotests with this yet. I wanted to, but they appear rather broken on current master, actually. I’m not yet sure whether that’s because something in my setup broke in the last two weeks, or because there’s quite something broken in master (it does look like there are a couple things broken in master currently). Max Reitz (18): configure: Detect libfuse fuse: Allow exporting BDSs via FUSE fuse: Implement standard FUSE operations fuse: Add fuse-export-remove fuse: Allow growable exports fuse: (Partially) implement fallocate() fuse: Implement hole detection through lseek iotests: Do not needlessly filter _make_test_img iotests: Do not pipe _make_test_img iotests: Use convert -n in some cases iotests: Avoid renaming images iotests: Derive image names from $TEST_IMG iotests/091: Use _cleanup_qemu instad of "wait" iotests: Restrict some Python tests to file iotests: Let _make_test_img guess $TEST_IMG_FILE iotests: Allow testing FUSE exports iotests: Enable fuse for many tests iotests/281: Add test for FUSE exports block.c | 4 + block/Makefile.objs | 3 + block/fuse.c | 668 +++++++++++++++++++++++++++++++ configure | 68 ++++ include/block/fuse.h | 24 ++ qapi/block.json | 42 ++ tests/qemu-iotests/013 | 9 +- tests/qemu-iotests/013.out | 3 +- tests/qemu-iotests/018 | 5 +- tests/qemu-iotests/018.out | 1 + tests/qemu-iotests/020 | 2 +- tests/qemu-iotests/025 | 2 +- tests/qemu-iotests/026 | 2 +- tests/qemu-iotests/028 | 16 +- tests/qemu-iotests/028.out | 3 + tests/qemu-iotests/031 | 2 +- tests/qemu-iotests/034 | 2 +- tests/qemu-iotests/036 | 2 +- tests/qemu-iotests/037 | 2 +- tests/qemu-iotests/038 | 2 +- tests/qemu-iotests/039 | 2 +- tests/qemu-iotests/046 | 7 +- tests/qemu-iotests/046.out | 2 +- tests/qemu-iotests/050 | 2 +- tests/qemu-iotests/054 | 2 +- tests/qemu-iotests/060 | 2 +- tests/qemu-iotests/071 | 21 +- tests/qemu-iotests/072 | 5 +- tests/qemu-iotests/072.out | 1 + tests/qemu-iotests/079 | 2 +- tests/qemu-iotests/080 | 2 +- tests/qemu-iotests/089 | 5 +- tests/qemu-iotests/089.out | 1 + tests/qemu-iotests/090 | 2 +- tests/qemu-iotests/091 | 5 +- tests/qemu-iotests/095 | 2 +- tests/qemu-iotests/097 | 2 +- tests/qemu-iotests/098 | 2 +- tests/qemu-iotests/102 | 2 +- tests/qemu-iotests/103 | 2 +- tests/qemu-iotests/106 | 2 +- tests/qemu-iotests/107 | 2 +- tests/qemu-iotests/108 | 2 +- tests/qemu-iotests/111 | 2 +- tests/qemu-iotests/112 | 2 +- tests/qemu-iotests/115 | 2 +- tests/qemu-iotests/117 | 2 +- tests/qemu-iotests/120 | 2 +- tests/qemu-iotests/121 | 2 +- tests/qemu-iotests/127 | 2 +- tests/qemu-iotests/133 | 2 +- tests/qemu-iotests/137 | 2 +- tests/qemu-iotests/138 | 2 +- tests/qemu-iotests/140 | 2 +- tests/qemu-iotests/154 | 2 +- tests/qemu-iotests/161 | 14 +- tests/qemu-iotests/171 | 2 +- tests/qemu-iotests/174 | 10 +- tests/qemu-iotests/175 | 8 +- tests/qemu-iotests/176 | 2 +- tests/qemu-iotests/177 | 2 +- tests/qemu-iotests/179 | 2 +- tests/qemu-iotests/183 | 2 +- tests/qemu-iotests/186 | 2 +- tests/qemu-iotests/187 | 2 +- tests/qemu-iotests/191 | 2 +- tests/qemu-iotests/195 | 2 +- tests/qemu-iotests/200 | 5 +- tests/qemu-iotests/200.out | 4 +- tests/qemu-iotests/204 | 2 +- tests/qemu-iotests/206 | 1 + tests/qemu-iotests/214 | 2 +- tests/qemu-iotests/217 | 2 +- tests/qemu-iotests/220 | 2 +- tests/qemu-iotests/221 | 2 +- tests/qemu-iotests/229 | 5 +- tests/qemu-iotests/229.out | 6 +- tests/qemu-iotests/242 | 1 + tests/qemu-iotests/247 | 2 +- tests/qemu-iotests/249 | 8 +- tests/qemu-iotests/250 | 2 +- tests/qemu-iotests/252 | 2 +- tests/qemu-iotests/265 | 2 +- tests/qemu-iotests/268 | 2 +- tests/qemu-iotests/272 | 2 +- tests/qemu-iotests/273 | 2 +- tests/qemu-iotests/279 | 2 +- tests/qemu-iotests/281 | 328 +++++++++++++++ tests/qemu-iotests/281.out | 92 +++++ tests/qemu-iotests/check | 6 + tests/qemu-iotests/common.filter | 5 +- tests/qemu-iotests/common.rc | 190 ++++++++- tests/qemu-iotests/group | 1 + 93 files changed, 1571 insertions(+), 120 deletions(-) create mode 100644 block/fuse.c create mode 100644 include/block/fuse.h create mode 100755 tests/qemu-iotests/281 create mode 100644 tests/qemu-iotests/281.out -- 2.23.0
