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5314d25afb
Remove test_generic_01.sh since block layer may reorder I/O, making the test prone to false positives. Apply the improvements to test_generic_02.sh instead, which supposes for covering ublk dispatch io order. Rework test_generic_02 to verify that ublk dispatch doesn't reorder I/O by comparing request start order with completion order using bpftrace. The bpftrace script now: - Tracks each request's start sequence number in a map keyed by sector - On completion, verifies the request's start order matches expected completion order - Reports any out-of-order completions detected The test script: - Wait bpftrace BEGIN code block is run - Pins fio to CPU 0 for deterministic behavior - Uses block_io_start and block_rq_complete tracepoints - Checks bpftrace output for reordering errors Reported-and-tested-by: Alexander Atanasov <alex@zazolabs.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
56 lines
1.2 KiB
Bash
Executable File
56 lines
1.2 KiB
Bash
Executable File
#!/bin/bash
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# SPDX-License-Identifier: GPL-2.0
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. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh
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ERR_CODE=0
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if ! _have_program bpftrace; then
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exit "$UBLK_SKIP_CODE"
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fi
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if ! _have_program fio; then
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exit "$UBLK_SKIP_CODE"
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fi
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_prep_test "null" "ublk dispatch won't reorder IO for MQ"
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dev_id=$(_add_ublk_dev -t null -q 2)
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_check_add_dev $TID $?
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dev_t=$(_get_disk_dev_t "$dev_id")
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bpftrace trace/seq_io.bt "$dev_t" "W" 1 > "$UBLK_TMP" 2>&1 &
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btrace_pid=$!
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# Wait for bpftrace probes to be attached (BEGIN block prints BPFTRACE_READY)
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for _ in $(seq 100); do
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grep -q "BPFTRACE_READY" "$UBLK_TMP" 2>/dev/null && break
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sleep 0.1
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done
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if ! kill -0 "$btrace_pid" 2>/dev/null; then
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_cleanup_test "null"
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exit "$UBLK_SKIP_CODE"
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fi
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# run fio over this ublk disk (pinned to CPU 0)
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taskset -c 0 fio --name=write_seq \
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--filename=/dev/ublkb"${dev_id}" \
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--ioengine=libaio --iodepth=16 \
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--rw=write \
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--size=512M \
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--direct=1 \
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--bs=4k > /dev/null 2>&1
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ERR_CODE=$?
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kill "$btrace_pid"
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wait
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# Check for out-of-order completions detected by bpftrace
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if grep -q "^out_of_order:" "$UBLK_TMP"; then
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echo "I/O reordering detected:"
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grep "^out_of_order:" "$UBLK_TMP"
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ERR_CODE=255
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fi
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_cleanup_test "null"
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_show_result $TID $ERR_CODE
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