2021-03-16 10:16:06 sed "s:^:nbd/:" /lkp/benchmarks/blktests/tests/nbd-group-01
2021-03-16 10:16:06 ./check nbd/002 nbd/003
nbd/002 (tests on partition handling for an nbd device)     
nbd/002 (tests on partition handling for an nbd device)      [passed]
    runtime  ...  1.720s
nbd/003 (mount/unmount concurrently with NBD_CLEAR_SOCK)    
nbd/003 (mount/unmount concurrently with NBD_CLEAR_SOCK)     [failed]
    runtime  ...  29.240s
    something found in dmesg:
    [   29.921062] run blktests nbd/003 at 2021-03-16 10:16:07
    [   30.264811] nbd0: detected capacity change from 0 to 20971520
    [   30.329518] block nbd0: shutting down sockets
    [   30.336573] blk_update_request: I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x1000 phys_seg 1 prio class 0
    [   30.346775] EXT4-fs (nbd0): unable to read superblock
    [   30.352216] blk_update_request: I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
    [   30.362140] Buffer I/O error on dev nbd0, logical block 0, async page read
    [   30.369024] blk_update_request: I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 3 prio class 0
    [   30.378924] Buffer I/O error on dev nbd0, logical block 1, async page read
    [   30.385791] Buffer I/O error on dev nbd0, logical block 2, async page read
    ...
    (See '/lkp/benchmarks/blktests/results/nodev/nbd/003.dmesg' for the entire message)