Add mknod test case

Tests success (fifo, char dev), EEXISTS, ENOENT (no parent dir).

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
Link: https://lore.kernel.org/r/20210603052906.2616489-12-dkadashev@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

3 files changed, 158 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index 7a6f75c..93cc1ea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -70,6 +70,7 @@
 /test/link_drain
 /test/madvise
 /test/mkdir
+/test/mknod
 /test/nop
 /test/nop-all-sizes
 /test/open-close
diff --git a/test/Makefile b/test/Makefile
index 2f0a694..fbc6c0f 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -67,6 +67,7 @@ test_targets += \
 	link_drain \
 	madvise \
 	mkdir \
+	mknod \
 	multicqes_drain \
 	nop \
 	nop-all-sizes \
@@ -207,6 +208,7 @@ test_srcs := \
 	link_drain.c \
 	madvise.c \
 	mkdir.c \
+	mknod.c \
 	multicqes_drain.c \
 	nop-all-sizes.c \
 	nop.c \
diff --git a/test/mknod.c b/test/mknod.c
new file mode 100644
index 0000000..d82e243
--- /dev/null
+++ b/test/mknod.c
@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Description: test io_uring mknodat handling
+ */
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "liburing.h"
+
+static int do_mknodat(struct io_uring *ring, const char *fn, mode_t mode, dev_t dev)
+{
+	int ret;
+	struct io_uring_sqe *sqe;
+	struct io_uring_cqe *cqe;
+
+	sqe = io_uring_get_sqe(ring);
+	if (!sqe) {
+		fprintf(stderr, "sqe get failed\n");
+		goto err;
+	}
+	io_uring_prep_mknodat(sqe, AT_FDCWD, fn, mode, dev);
+
+	ret = io_uring_submit(ring);
+	if (ret != 1) {
+		fprintf(stderr, "submit failed: %d\n", ret);
+		goto err;
+	}
+
+	ret = io_uring_wait_cqes(ring, &cqe, 1, 0, 0);
+	if (ret) {
+		fprintf(stderr, "wait_cqe failed: %d\n", ret);
+		goto err;
+	}
+	ret = cqe->res;
+	io_uring_cqe_seen(ring, cqe);
+	return ret;
+err:
+	return 1;
+}
+
+int check_fifo(const char* fn)
+{
+	char buf[4];
+	int fd = open(fn, O_RDWR);
+	if (fd < 0) {
+		fprintf(stderr, "failed to open fifo: %s\n", strerror(errno));
+		return 1;
+	}
+	if (write(fd, "42", 2) != 2) {
+		fprintf(stderr, "short write to fifo\n");
+		return 1;
+	}
+	if (read(fd, buf, 2) != 2) {
+		fprintf(stderr, "short read from fifo\n");
+		return 1;
+	}
+	buf[3] = 0;
+	if (strncmp(buf, "42", 2)) {
+		fprintf(stderr, "read unexpected data from fifo: %s\n", buf);
+		return 1;
+	}
+
+	return 0;
+}
+
+int test_device(struct io_uring *ring, const char* fn)
+{
+	// 1, 3 is /dev/null
+	struct stat sb;
+	dev_t dev = makedev(1, 3);
+	int ret = do_mknodat(ring, fn, 0600 | S_IFCHR, dev);
+	if (ret < 0) {
+		fprintf(stderr, "mknodat device: %s\n", strerror(-ret));
+		return ret;
+	} else if (ret) {
+		return ret;
+	}
+	ret = stat(fn, &sb);
+	if (ret) {
+		perror("stat");
+		return ret;
+	}
+	if (sb.st_rdev != dev) {
+		fprintf(stderr, "unexpected device number: %d, %d\n",
+			major(sb.st_rdev), minor(sb.st_rdev));
+		return 1;
+	}
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	static const char fn[] = "io_uring-mknodat-test";
+	int ret;
+	struct io_uring ring;
+
+	ret = io_uring_queue_init(8, &ring, 0);
+	if (ret) {
+		fprintf(stderr, "queue init failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = do_mknodat(&ring, fn, 0600 | S_IFIFO, 0);
+	if (ret < 0) {
+		if (ret == -EBADF || ret == -EINVAL) {
+			fprintf(stdout, "mknodat not supported, skipping\n");
+			goto out;
+		}
+		fprintf(stderr, "mknodat: %s\n", strerror(-ret));
+		goto err;
+	} else if (ret) {
+		goto err;
+	}
+
+
+	if (check_fifo(fn))
+		goto err1;
+
+	ret = do_mknodat(&ring, fn, 0600 | S_IFIFO, 0);
+	if (ret != -EEXIST) {
+		fprintf(stderr, "do_mknodat already exists failed: %d\n", ret);
+		goto err1;
+	}
+
+	ret = do_mknodat(&ring, "surely/this/wont/exist", 0600 | S_IFIFO, 0);
+	if (ret != -ENOENT) {
+		fprintf(stderr, "do_mkdirat no parent failed: %d\n", ret);
+		goto err1;
+	}
+
+	unlinkat(AT_FDCWD, fn, 0);
+
+	if (!geteuid()) {
+		if (test_device(&ring, fn))
+			goto err1;
+	}
+	else
+		fprintf(stdout, "skipping the device test which needs root perms\n");
+
+out:
+	unlinkat(AT_FDCWD, fn, 0);
+	io_uring_queue_exit(&ring);
+	return 0;
+err1:
+	unlinkat(AT_FDCWD, fn, 0);
+err:
+	io_uring_queue_exit(&ring);
+	return 1;
+}
+