[LTP] [PATCH v7 1/4] io_uring: Add io_uring04 test for vectored I/O operations
Sachin Sant
sachinp@linux.ibm.com
Thu May 7 09:34:14 CEST 2026
Add new test case io_uring04.c to validate IORING_OP_READV and
IORING_OP_WRITEV operations with uniform buffer sizes.
Test performs:
- Vectored write using multiple uniform buffers (4 x 1024 bytes)
- Vectored read back into multiple uniform buffers
- Data integrity verification across all vectors
Also add helper functions to io_uring_common.h:
- io_uring_init_iovec_pattern(): Initialize iovec buffers with patterns
- io_uring_clear_iovec(): Clear iovec buffers by zeroing data
- io_uring_verify_iovec(): Verify data integrity between write/read iovecs
Update runtest/syscalls and .gitignore to include the new test.
Signed-off-by: Sachin Sant <sachinp@linux.ibm.com>
---
V7 changes:
- Declare fd as static with file scope.
- Reset fd at the top of run(), and close it in cleanup()
- Link to v6 https://lore.kernel.org/ltp/20260506183750.97191-1-sachinp@linux.ibm.com/T/#t
V6 changes:
- Split io_uring04.c into 3 independent tests
- Link to v5 https://lore.kernel.org/ltp/69fb33a1.5d0a0220.337e29.6038@mx.google.com/T/#t
V5 changes:
- Add clear_iovec_buffers() at the top of run()
- Link to v4 https://lore.kernel.org/ltp/20260416062302.15804-1-sachinp@linux.ibm.com/T/
V4 changes:
- Updated commit message to remove references to non-existent function
- Removed extra blank line before test_writev_readv()
- Link to v3 https://lore.kernel.org/ltp/20260416042531.81093-1-sachinp@linux.ibm.com/T/
V3 changes (2/3 io_uring04 only):
- 1/3 and 3/3 from the patch series already merged.
- Merged prepare_read_buffers() and clear_iovec_buffers() into
single clear_iovec_buffers() function
- Merged io_uring_init_buffer_pattern() into unified
init_iovec_buffers() function that supports both rotating and
simple character patterns
- Removed io_uring_init_buffer_pattern() from io_uring_common.h as it's
only used in io_uring04.c
- Link to V2: https://lore.kernel.org/ltp/b4653e3f-ac9b-4a24-8d3f-51677c488e8c@linux.ibm.com/T/
V2 changes:
- Use guarded buffer(including iovec) allocation
- Move setup/cleanup code from run to appropriate path
- Add a function to map the OP to the enum name
- Define and use generic cleanup functions
- Add a buffer size 0 in the middle of the iovec
- Simplify setup_io_uring_test to use common code.
- Link to V1: https://lore.kernel.org/ltp/20260320124742.75946-1-sachinp@linux.ibm.com/T/#t
Changes after RFC patch series:
- Addressed review comments
- Refactored io_uring01 test to use common code
- Removed git tags
- Link to RFC: https://lore.kernel.org/ltp/20260318110328.52031-1-sachinp@linux.ibm.com/T/#t
---
runtest/syscalls | 1 +
testcases/kernel/syscalls/io_uring/.gitignore | 1 +
.../kernel/syscalls/io_uring/io_uring04.c | 89 +++++++++++++++++++
.../syscalls/io_uring/io_uring_common.h | 86 ++++++++++++++++++
4 files changed, 177 insertions(+)
create mode 100644 testcases/kernel/syscalls/io_uring/io_uring04.c
diff --git a/runtest/syscalls b/runtest/syscalls
index f790e8f84..6b047b5fd 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1904,6 +1904,7 @@ membarrier01 membarrier01
io_uring01 io_uring01
io_uring02 io_uring02
io_uring03 io_uring03
+io_uring04 io_uring04
# Tests below may cause kernel memory leak
perf_event_open03 perf_event_open03
diff --git a/testcases/kernel/syscalls/io_uring/.gitignore b/testcases/kernel/syscalls/io_uring/.gitignore
index 9382ae413..36cd24662 100644
--- a/testcases/kernel/syscalls/io_uring/.gitignore
+++ b/testcases/kernel/syscalls/io_uring/.gitignore
@@ -1,3 +1,4 @@
/io_uring01
/io_uring02
/io_uring03
+/io_uring04
diff --git a/testcases/kernel/syscalls/io_uring/io_uring04.c b/testcases/kernel/syscalls/io_uring/io_uring04.c
new file mode 100644
index 000000000..652a2b2cb
--- /dev/null
+++ b/testcases/kernel/syscalls/io_uring/io_uring04.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2026 IBM
+ * Author: Sachin Sant <sachinp@linux.ibm.com>
+ */
+/*\
+ * Test basic IORING_OP_READV and IORING_OP_WRITEV operations.
+ *
+ * This test validates basic vectored read and write operations using
+ * io_uring with uniform buffer sizes. It performs:
+ * 1. IORING_OP_WRITEV - Writing data using multiple uniform buffers
+ * 2. IORING_OP_READV - Reading data back into multiple uniform buffers
+ * 3. Data integrity verification across all vectors
+ */
+
+#include "io_uring_common.h"
+
+#define TEST_FILE "io_uring_test_file"
+#define QUEUE_DEPTH 2
+#define NUM_VECS 4
+#define VEC_SIZE 1024
+
+static struct iovec *write_iovs, *read_iovs;
+static struct io_uring_submit s;
+static sigset_t sig;
+static int fd = -1;
+
+static void run(void)
+{
+ int total_size = NUM_VECS * VEC_SIZE;
+
+ fd = -1;
+
+ io_uring_init_iovec_pattern(write_iovs, NUM_VECS, 'A', 1);
+ io_uring_clear_iovec(read_iovs, NUM_VECS);
+
+ fd = SAFE_OPEN(TEST_FILE, O_RDWR | O_CREAT | O_TRUNC, 0644);
+
+ tst_res(TINFO, "Writing %d bytes using %d vectors",
+ total_size, NUM_VECS);
+ io_uring_do_vec_io_op(&s, fd, IORING_OP_WRITEV, write_iovs, NUM_VECS,
+ 0, total_size, &sig);
+
+ SAFE_FSYNC(fd);
+
+ tst_res(TINFO, "Reading %d bytes using %d vectors",
+ total_size, NUM_VECS);
+ io_uring_do_vec_io_op(&s, fd, IORING_OP_READV, read_iovs, NUM_VECS,
+ 0, total_size, &sig);
+
+ io_uring_verify_iovec(write_iovs, read_iovs, NUM_VECS);
+
+ SAFE_CLOSE(fd);
+}
+
+static void setup(void)
+{
+ io_uring_setup_supported_by_kernel();
+ sigemptyset(&sig);
+ memset(&s, 0, sizeof(s));
+ io_uring_setup_queue(&s, QUEUE_DEPTH, 0);
+}
+
+static void cleanup(void)
+{
+ if (fd >= 0)
+ SAFE_CLOSE(fd);
+
+ io_uring_cleanup_queue(&s, QUEUE_DEPTH);
+}
+
+static struct tst_test test = {
+ .test_all = run,
+ .setup = setup,
+ .cleanup = cleanup,
+ .needs_tmpdir = 1,
+ .bufs = (struct tst_buffers []) {
+ {&write_iovs, .iov_sizes = (int[]){VEC_SIZE, VEC_SIZE,
+ VEC_SIZE, VEC_SIZE, -1}},
+ {&read_iovs, .iov_sizes = (int[]){VEC_SIZE, VEC_SIZE,
+ VEC_SIZE, VEC_SIZE, -1}},
+ {}
+ },
+ .save_restore = (const struct tst_path_val[]) {
+ {"/proc/sys/kernel/io_uring_disabled", "0",
+ TST_SR_SKIP_MISSING | TST_SR_TCONF_RO},
+ {}
+ }
+};
diff --git a/testcases/kernel/syscalls/io_uring/io_uring_common.h b/testcases/kernel/syscalls/io_uring/io_uring_common.h
index aa31339fb..523f686f8 100644
--- a/testcases/kernel/syscalls/io_uring/io_uring_common.h
+++ b/testcases/kernel/syscalls/io_uring/io_uring_common.h
@@ -275,4 +275,90 @@ static inline void io_uring_do_vec_io_op(struct io_uring_submit *s, int fd,
expected_size);
}
+/*
+ * Initialize iovec buffers with pattern
+ * @iovs: array of iovec structures
+ * @nvecs: number of iovecs
+ * @base_char: base character for pattern (must be 'A'-'Z')
+ * @use_rotating: if non-zero, use rotating pattern; if zero, use simple repeat
+ */
+static inline void io_uring_init_iovec_pattern(struct iovec *iovs, int nvecs,
+ char base_char, int use_rotating)
+{
+ int i;
+ size_t j;
+ char *buf;
+
+ if (base_char < 'A' || base_char > 'Z')
+ tst_brk(TBROK, "base_char must be 'A'-'Z', got '%c'",
+ base_char);
+
+ for (i = 0; i < nvecs; i++) {
+ if (iovs[i].iov_len == 0)
+ continue;
+
+ buf = (char *)iovs[i].iov_base;
+ if (use_rotating) {
+ /* Each vector has a different rotating pattern */
+ for (j = 0; j < iovs[i].iov_len; j++)
+ buf[j] = 'A' + ((base_char - 'A' + i + j) % 26);
+ } else {
+ for (j = 0; j < iovs[i].iov_len; j++)
+ buf[j] = 'A' + ((base_char - 'A' + i) % 26);
+ }
+ }
+}
+
+/*
+ * Clear iovec buffers by zeroing all data
+ */
+static inline void io_uring_clear_iovec(struct iovec *iovs, int nvecs)
+{
+ int i;
+
+ for (i = 0; i < nvecs; i++)
+ memset(iovs[i].iov_base, 0, iovs[i].iov_len);
+}
+
+/*
+ * Verify data integrity between write and read iovecs
+ * Stops test execution on verification failure
+ */
+static inline void io_uring_verify_iovec(struct iovec *write_iovs,
+ struct iovec *read_iovs, int nvecs)
+{
+ int i;
+ size_t j;
+
+ for (i = 0; i < nvecs; i++) {
+ if (write_iovs[i].iov_len != read_iovs[i].iov_len) {
+ tst_brk(TFAIL,
+ "iovec %d length mismatch: write=%zu read=%zu",
+ i, write_iovs[i].iov_len, read_iovs[i].iov_len);
+ }
+
+ if (memcmp(write_iovs[i].iov_base, read_iovs[i].iov_base,
+ write_iovs[i].iov_len) != 0) {
+ for (j = 0; j < write_iovs[i].iov_len; j++) {
+ char *wbuf = (char *)write_iovs[i].iov_base;
+ char *rbuf = (char *)read_iovs[i].iov_base;
+
+ if (wbuf[j] != rbuf[j]) {
+ tst_res(TINFO,
+ "Vector %d: first mismatch at "
+ "offset %zu: wrote 0x%02x, "
+ "read 0x%02x",
+ i, j,
+ (unsigned char)wbuf[j],
+ (unsigned char)rbuf[j]);
+ break;
+ }
+ }
+ tst_brk(TFAIL, "data mismatch in vector %d", i);
+ }
+ }
+
+ tst_res(TPASS, "data integrity verified across %d vectors", nvecs);
+}
+
#endif /* IO_URING_COMMON_H */
--
2.39.1
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