[PATCH v3 7/9] selftests: ublk: forbid multiple data copy modes
From: Caleb Sander Mateos <hidden>
Date: 2025-12-12 17:17:11
Also in:
linux-kselftest, lkml
Subsystem:
kernel selftest framework, the rest, ublk userspace block driver · Maintainers:
Shuah Khan, Linus Torvalds, Ming Lei
The kublk mock ublk server allows multiple data copy mode arguments to be passed on the command line (--zero_copy, --get_data, and --auto_zc). The ublk device will be created with all the requested feature flags, however kublk will only use one of the modes to interact with request data (arbitrarily preferring auto_zc over zero_copy over get_data). To clarify the intent of the test, don't allow multiple data copy modes to be specified. --zero_copy and --auto_zc are allowed together for --auto_zc_fallback, which uses both copy modes. Don't set UBLK_F_USER_COPY for zero_copy, as it's a separate feature. Fix the test cases in test_stress_05 passing --get_data along with --zero_copy or --auto_zc. Signed-off-by: Caleb Sander Mateos <redacted> Reviewed-by: Ming Lei <redacted> --- tools/testing/selftests/ublk/kublk.c | 11 ++++++++++- tools/testing/selftests/ublk/test_stress_05.sh | 10 +++++----- 2 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/ublk/kublk.c b/tools/testing/selftests/ublk/kublk.c
index f8fa102a627f..4dd02cb083ba 100644
--- a/tools/testing/selftests/ublk/kublk.c
+++ b/tools/testing/selftests/ublk/kublk.c@@ -1611,11 +1611,11 @@ int main(int argc, char *argv[]) break; case 'd': ctx.queue_depth = strtol(optarg, NULL, 10); break; case 'z': - ctx.flags |= UBLK_F_SUPPORT_ZERO_COPY | UBLK_F_USER_COPY; + ctx.flags |= UBLK_F_SUPPORT_ZERO_COPY; break; case 'r': value = strtol(optarg, NULL, 10); if (value) ctx.flags |= UBLK_F_USER_RECOVERY;
@@ -1684,10 +1684,19 @@ int main(int argc, char *argv[]) "F_AUTO_BUF_REG nor F_SUPPORT_ZERO_COPY is enabled\n", __func__); return -EINVAL; } + if (!!(ctx.flags & UBLK_F_NEED_GET_DATA) + + !!(ctx.flags & UBLK_F_USER_COPY) + + (ctx.flags & UBLK_F_SUPPORT_ZERO_COPY && !ctx.auto_zc_fallback) + + (ctx.flags & UBLK_F_AUTO_BUF_REG && !ctx.auto_zc_fallback) + + ctx.auto_zc_fallback > 1) { + fprintf(stderr, "too many data copy modes specified\n"); + return -EINVAL; + } + i = optind; while (i < argc && ctx.nr_files < MAX_BACK_FILES) { ctx.files[ctx.nr_files++] = argv[i++]; }
diff --git a/tools/testing/selftests/ublk/test_stress_05.sh b/tools/testing/selftests/ublk/test_stress_05.sh
index 274295061042..68a194144302 100755
--- a/tools/testing/selftests/ublk/test_stress_05.sh
+++ b/tools/testing/selftests/ublk/test_stress_05.sh@@ -56,21 +56,21 @@ for reissue in $(seq 0 1); do wait done if _have_feature "ZERO_COPY"; then for reissue in $(seq 0 1); do - ublk_io_and_remove 8G -t null -q 4 -g -z -r 1 -i "$reissue" & - ublk_io_and_remove 256M -t loop -q 4 -g -z -r 1 -i "$reissue" "${UBLK_BACKFILES[1]}" & + ublk_io_and_remove 8G -t null -q 4 -z -r 1 -i "$reissue" & + ublk_io_and_remove 256M -t loop -q 4 -z -r 1 -i "$reissue" "${UBLK_BACKFILES[1]}" & wait done fi if _have_feature "AUTO_BUF_REG"; then for reissue in $(seq 0 1); do - ublk_io_and_remove 8G -t null -q 4 -g --auto_zc -r 1 -i "$reissue" & - ublk_io_and_remove 256M -t loop -q 4 -g --auto_zc -r 1 -i "$reissue" "${UBLK_BACKFILES[1]}" & - ublk_io_and_remove 8G -t null -q 4 -g -z --auto_zc --auto_zc_fallback -r 1 -i "$reissue" & + ublk_io_and_remove 8G -t null -q 4 --auto_zc -r 1 -i "$reissue" & + ublk_io_and_remove 256M -t loop -q 4 --auto_zc -r 1 -i "$reissue" "${UBLK_BACKFILES[1]}" & + ublk_io_and_remove 8G -t null -q 4 -z --auto_zc --auto_zc_fallback -r 1 -i "$reissue" & wait done fi if _have_feature "PER_IO_DAEMON"; then
--
2.45.2