[PATCH liburing v2 00/11] add mkdir, [sym]linkat, mknodat support

[PATCH liburing v2 00/11] add mkdir, [sym]linkat, mknodat support

[Dmitry Kadashev]

This started as an attempt to add mkdir support to io_uring, but in the
end more ops were added. Heavily based on a series that added unlinkat
support (commit: 44db0f437a2b ("io_uring.h: add renameat and unlinkat
opcodes") and a couple of subsequent ones).

The kernel side of the change:
https://lore.kernel.org/io-uring/20210603051836.2614535-1-dkadashev@gmail.com/T/

1-2 adds mkdirat support (the opcode is already there) and test
3-5 adds symlinkat support and test
6-8 adds linkat support and test
9-11 adds mknodat support and test

v2:
- add symlinkat, linkat, mknodat

Dmitry Kadashev (11):
  liburing.h: add mkdirat prep helper
  Add mkdirat test case
  io_uring.h: add symlinkat opcode
  liburing.h: add symlinkat prep helper
  Add symlinkat test case
  io_uring.h: add linkat opcode
  liburing.h: add linkat prep helper
  Add linkat test case
  io_uring.h: add mknodat opcode
  liburing.h: add mknodat prep helper
  Add mknod test case

 .gitignore                      |   4 +
 src/include/liburing.h          |  29 ++++++
 src/include/liburing/io_uring.h |   5 ++
 test/Makefile                   |   8 ++
 test/hardlink.c                 | 133 +++++++++++++++++++++++++++
 test/mkdir.c                    | 105 ++++++++++++++++++++++
 test/mknod.c                    | 155 ++++++++++++++++++++++++++++++++
 test/symlink.c                  | 113 +++++++++++++++++++++++
 8 files changed, 552 insertions(+)
 create mode 100644 test/hardlink.c
 create mode 100644 test/mkdir.c
 create mode 100644 test/mknod.c
 create mode 100644 test/symlink.c

-- 
2.30.2

[PATCH liburing v2 01/11] liburing.h: add mkdirat prep helper

[Dmitry Kadashev]

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 src/include/liburing.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/include/liburing.h b/src/include/liburing.h
index d3f8f91..b7f3bea 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -548,6 +548,12 @@ static inline void io_uring_prep_sync_file_range(struct io_uring_sqe *sqe,
 	sqe->sync_range_flags = flags;
 }
 
+static inline void io_uring_prep_mkdirat(struct io_uring_sqe *sqe, int dfd,
+					const char *path, mode_t mode)
+{
+	io_uring_prep_rw(IORING_OP_MKDIRAT, sqe, dfd, path, mode, 0);
+}
+
 /*
  * Returns number of unconsumed (if SQPOLL) or unsubmitted entries exist in
  * the SQ ring
-- 
2.30.2

[PATCH liburing v2 02/11] Add mkdirat test case

[Dmitry Kadashev]

The test is relative basic: tests only success, EEXISTS, ENOENT (no
parent dir).

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 .gitignore    |   1 +
 test/Makefile |   2 +
 test/mkdir.c  | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 108 insertions(+)
 create mode 100644 test/mkdir.c

diff --git a/.gitignore b/.gitignore
index 17ec415..a9ae5bb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -68,6 +68,7 @@
 /test/link-timeout
 /test/link_drain
 /test/madvise
+/test/mkdir
 /test/nop
 /test/nop-all-sizes
 /test/open-close
diff --git a/test/Makefile b/test/Makefile
index a312409..86437d5 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -65,6 +65,7 @@ test_targets += \
 	link-timeout \
 	link_drain \
 	madvise \
+	mkdir \
 	multicqes_drain \
 	nop \
 	nop-all-sizes \
@@ -202,6 +203,7 @@ test_srcs := \
 	link.c \
 	link_drain.c \
 	madvise.c \
+	mkdir.c \
 	multicqes_drain.c \
 	nop-all-sizes.c \
 	nop.c \
diff --git a/test/mkdir.c b/test/mkdir.c
new file mode 100644
index 0000000..c044652
--- /dev/null
+++ b/test/mkdir.c
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Description: test io_uring mkdirat handling
+ */
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "liburing.h"
+
+static int do_mkdirat(struct io_uring *ring, const char *fn)
+{
+	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_mkdirat(sqe, AT_FDCWD, fn, 0700);
+
+	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;
+}
+
+static int stat_file(const char *fn)
+{
+	struct stat sb;
+
+	if (!stat(fn, &sb))
+		return 0;
+
+	return errno;
+}
+
+int main(int argc, char *argv[])
+{
+	static const char fn[] = "io_uring-mkdirat-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_mkdirat(&ring, fn);
+	if (ret < 0) {
+		if (ret == -EBADF || ret == -EINVAL) {
+			fprintf(stdout, "mkdirat not supported, skipping\n");
+			goto out;
+		}
+		fprintf(stderr, "mkdirat: %s\n", strerror(-ret));
+		goto err;
+	} else if (ret) {
+		goto err;
+	}
+
+	if (stat_file(fn)) {
+		perror("stat");
+		goto err;
+	}
+
+	ret = do_mkdirat(&ring, fn);
+	if (ret != -EEXIST) {
+		fprintf(stderr, "do_mkdirat already exists failed: %d\n", ret);
+		goto err1;
+	}
+
+	ret = do_mkdirat(&ring, "surely/this/wont/exist");
+	if (ret != -ENOENT) {
+		fprintf(stderr, "do_mkdirat no parent failed: %d\n", ret);
+		goto err1;
+	}
+
+out:
+	unlinkat(AT_FDCWD, fn, AT_REMOVEDIR);
+	io_uring_queue_exit(&ring);
+	return 0;
+err1:
+	unlinkat(AT_FDCWD, fn, AT_REMOVEDIR);
+err:
+	io_uring_queue_exit(&ring);
+	return 1;
+}
-- 
2.30.2

[PATCH liburing v2 03/11] io_uring.h: add symlinkat opcode

[Dmitry Kadashev]

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 src/include/liburing/io_uring.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/include/liburing/io_uring.h b/src/include/liburing/io_uring.h
index 5a3cb90..439a515 100644
--- a/src/include/liburing/io_uring.h
+++ b/src/include/liburing/io_uring.h
@@ -142,6 +142,7 @@ enum {
 	IORING_OP_RENAMEAT,
 	IORING_OP_UNLINKAT,
 	IORING_OP_MKDIRAT,
+	IORING_OP_SYMLINKAT,
 
 	/* this goes last, obviously */
 	IORING_OP_LAST,
-- 
2.30.2

[PATCH liburing v2 04/11] liburing.h: add symlinkat prep helper

[Dmitry Kadashev]

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 src/include/liburing.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/include/liburing.h b/src/include/liburing.h
index b7f3bea..e033543 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -554,6 +554,13 @@ static inline void io_uring_prep_mkdirat(struct io_uring_sqe *sqe, int dfd,
 	io_uring_prep_rw(IORING_OP_MKDIRAT, sqe, dfd, path, mode, 0);
 }
 
+static inline void io_uring_prep_symlinkat(struct io_uring_sqe *sqe,
+					const char *target, int newdirfd, const char *linkpath)
+{
+	io_uring_prep_rw(IORING_OP_SYMLINKAT, sqe, newdirfd, target, 0,
+				(uint64_t) (uintptr_t) linkpath);
+}
+
 /*
  * Returns number of unconsumed (if SQPOLL) or unsubmitted entries exist in
  * the SQ ring
-- 
2.30.2

[PATCH liburing v2 05/11] Add symlinkat test case

[Dmitry Kadashev]

Tests successful creation (using readlink() to verify the contents),
EEXIST, ENOENT cases.

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 .gitignore     |   1 +
 test/Makefile  |   2 +
 test/symlink.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 116 insertions(+)
 create mode 100644 test/symlink.c

diff --git a/.gitignore b/.gitignore
index a9ae5bb..0b336d6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -112,6 +112,7 @@
 /test/statx
 /test/stdout
 /test/submit-reuse
+/test/symlink
 /test/teardowns
 /test/thread-exit
 /test/timeout
diff --git a/test/Makefile b/test/Makefile
index 86437d5..4fc78ea 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -108,6 +108,7 @@ test_targets += \
 	sq-space_left \
 	stdout \
 	submit-reuse \
+	symlink \
 	teardowns \
 	thread-exit \
 	timeout \
@@ -248,6 +249,7 @@ test_srcs := \
 	statx.c \
 	stdout.c \
 	submit-reuse.c \
+	symlink.c \
 	teardowns.c \
 	thread-exit.c \
 	timeout-new.c \
diff --git a/test/symlink.c b/test/symlink.c
new file mode 100644
index 0000000..8b5e04a
--- /dev/null
+++ b/test/symlink.c
@@ -0,0 +1,113 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Description: test io_uring symlinkat handling
+ */
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "liburing.h"
+
+
+static int do_symlinkat(struct io_uring *ring, const char *oldname, const char *newname)
+{
+	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_symlinkat(sqe, oldname, AT_FDCWD, newname);
+
+	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 test_link_contents(const char* linkname, const char *expected_contents)
+{
+	char buf[128];
+	int ret = readlink(linkname, buf, 127);
+	if (ret < 0) {
+		perror("readlink");
+		return ret;
+	}
+	buf[ret] = 0;
+	if (strncmp(buf, expected_contents, 128)) {
+		fprintf(stderr, "link contents differs from expected: '%s' vs '%s'",
+			buf, expected_contents);
+		return -1;
+	}
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	static const char target[] = "io_uring-symlinkat-test-target";
+	static const char linkname[] = "io_uring-symlinkat-test-link";
+	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_symlinkat(&ring, target, linkname);
+	if (ret < 0) {
+		if (ret == -EBADF || ret == -EINVAL) {
+			fprintf(stdout, "symlinkat not supported, skipping\n");
+			goto out;
+		}
+		fprintf(stderr, "symlinkat: %s\n", strerror(-ret));
+		goto err;
+	} else if (ret) {
+		goto err;
+	}
+
+	ret = test_link_contents(linkname, target);
+	if (ret < 0)
+		goto err1;
+
+	ret = do_symlinkat(&ring, target, linkname);
+	if (ret != -EEXIST) {
+		fprintf(stderr, "test_symlinkat linkname already exists failed: %d\n", ret);
+		goto err1;
+	}
+
+	ret = do_symlinkat(&ring, target, "surely/this/does/not/exist");
+	if (ret != -ENOENT) {
+		fprintf(stderr, "test_symlinkat no parent failed: %d\n", ret);
+		goto err1;
+	}
+
+out:
+	unlinkat(AT_FDCWD, linkname, 0);
+	io_uring_queue_exit(&ring);
+	return 0;
+err1:
+	unlinkat(AT_FDCWD, linkname, 0);
+err:
+	io_uring_queue_exit(&ring);
+	return 1;
+}
-- 
2.30.2

[PATCH liburing v2 06/11] io_uring.h: add linkat opcode

[Dmitry Kadashev]

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 src/include/liburing/io_uring.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/include/liburing/io_uring.h b/src/include/liburing/io_uring.h
index 439a515..a5e48e7 100644
--- a/src/include/liburing/io_uring.h
+++ b/src/include/liburing/io_uring.h
@@ -48,6 +48,7 @@ struct io_uring_sqe {
 		__u32		splice_flags;
 		__u32		rename_flags;
 		__u32		unlink_flags;
+		__u32		hardlink_flags;
 	};
 	__u64	user_data;	/* data to be passed back at completion time */
 	union {
@@ -143,6 +144,7 @@ enum {
 	IORING_OP_UNLINKAT,
 	IORING_OP_MKDIRAT,
 	IORING_OP_SYMLINKAT,
+	IORING_OP_LINKAT,
 
 	/* this goes last, obviously */
 	IORING_OP_LAST,
-- 
2.30.2

[PATCH liburing v2 07/11] liburing.h: add linkat prep helper

[Dmitry Kadashev]

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 src/include/liburing.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/include/liburing.h b/src/include/liburing.h
index e033543..51dc602 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -561,6 +561,15 @@ static inline void io_uring_prep_symlinkat(struct io_uring_sqe *sqe,
 				(uint64_t) (uintptr_t) linkpath);
 }
 
+static inline void io_uring_prep_linkat(struct io_uring_sqe *sqe, int olddfd,
+					const char *oldpath, int newdfd,
+					const char *newpath, int flags)
+{
+	io_uring_prep_rw(IORING_OP_LINKAT, sqe, olddfd, oldpath, newdfd,
+				(uint64_t) (uintptr_t) newpath);
+	sqe->hardlink_flags = flags;
+}
+
 /*
  * Returns number of unconsumed (if SQPOLL) or unsubmitted entries exist in
  * the SQ ring
-- 
2.30.2

[PATCH liburing v2 08/11] Add linkat test case

[Dmitry Kadashev]

Tests success, EEXISTS, ENOENT (no parent dir).

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 .gitignore      |   1 +
 test/Makefile   |   2 +
 test/hardlink.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 136 insertions(+)
 create mode 100644 test/hardlink.c

diff --git a/.gitignore b/.gitignore
index 0b336d6..7a6f75c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -57,6 +57,7 @@
 /test/files-exit-hang-timeout
 /test/fixed-link
 /test/fsync
+/test/hardlink
 /test/io-cancel
 /test/io_uring_enter
 /test/io_uring_register
diff --git a/test/Makefile b/test/Makefile
index 4fc78ea..2f0a694 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -54,6 +54,7 @@ test_targets += \
 	files-exit-hang-timeout \
 	fixed-link \
 	fsync \
+	hardlink \
 	io-cancel \
 	io_uring_enter \
 	io_uring_register \
@@ -193,6 +194,7 @@ test_srcs := \
 	files-exit-hang-timeout.c \
 	fixed-link.c \
 	fsync.c \
+	hardlink.c \
 	io-cancel.c \
 	io_uring_enter.c \
 	io_uring_register.c \
diff --git a/test/hardlink.c b/test/hardlink.c
new file mode 100644
index 0000000..1c73424
--- /dev/null
+++ b/test/hardlink.c
@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Description: test io_uring linkat handling
+ */
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "liburing.h"
+
+
+static int do_linkat(struct io_uring *ring, const char *oldname, const char *newname)
+{
+	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_linkat(sqe, AT_FDCWD, oldname, AT_FDCWD, newname, 0);
+
+	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 files_linked_ok(const char* fn1, const char *fn2)
+{
+	struct stat s1, s2;
+
+	if (stat(fn1, &s1)) {
+		fprintf(stderr, "stat(%s): %s\n", fn1, strerror(errno));
+		return 0;
+	}
+	if (stat(fn2, &s2)) {
+		fprintf(stderr, "stat(%s): %s\n", fn2, strerror(errno));
+		return 0;
+	}
+	if (s1.st_dev != s2.st_dev || s1.st_ino != s2.st_ino) {
+		fprintf(stderr, "linked files have different device / inode numbers\n");
+		return 0;
+	}
+	if (s1.st_nlink != 2 || s2.st_nlink != 2) {
+		fprintf(stderr, "linked files have unexpected links count\n");
+		return 0;
+	}
+	return 1;
+}
+
+int main(int argc, char *argv[])
+{
+	static const char target[] = "io_uring-linkat-test-target";
+	static const char linkname[] = "io_uring-linkat-test-link";
+	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 = open(target, O_CREAT | O_RDWR | O_EXCL, 0600);
+	if (ret < 0) {
+		perror("open");
+		goto err;
+	}
+	if (write(ret, "linktest", 8) != 8) {
+		close(ret);
+		goto err1;
+	}
+	close(ret);
+
+	ret = do_linkat(&ring, target, linkname);
+	if (ret < 0) {
+		if (ret == -EBADF || ret == -EINVAL) {
+			fprintf(stdout, "linkat not supported, skipping\n");
+			goto out;
+		}
+		fprintf(stderr, "linkat: %s\n", strerror(-ret));
+		goto err1;
+	} else if (ret) {
+		goto err1;
+	}
+
+	if (!files_linked_ok(linkname, target))
+		goto err2;
+
+	ret = do_linkat(&ring, target, linkname);
+	if (ret != -EEXIST) {
+		fprintf(stderr, "test_linkat linkname already exists failed: %d\n", ret);
+		goto err2;
+	}
+
+	ret = do_linkat(&ring, target, "surely/this/does/not/exist");
+	if (ret != -ENOENT) {
+		fprintf(stderr, "test_linkat no parent failed: %d\n", ret);
+		goto err2;
+	}
+
+out:
+	unlinkat(AT_FDCWD, linkname, 0);
+	unlinkat(AT_FDCWD, target, 0);
+	io_uring_queue_exit(&ring);
+	return 0;
+err2:
+	unlinkat(AT_FDCWD, linkname, 0);
+err1:
+	unlinkat(AT_FDCWD, target, 0);
+err:
+	io_uring_queue_exit(&ring);
+	return 1;
+}
+
-- 
2.30.2

[PATCH liburing v2 09/11] io_uring.h: add mknodat opcode

[Dmitry Kadashev]

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 src/include/liburing/io_uring.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/include/liburing/io_uring.h b/src/include/liburing/io_uring.h
index a5e48e7..46cd2fc 100644
--- a/src/include/liburing/io_uring.h
+++ b/src/include/liburing/io_uring.h
@@ -49,6 +49,7 @@ struct io_uring_sqe {
 		__u32		rename_flags;
 		__u32		unlink_flags;
 		__u32		hardlink_flags;
+		__u32		mknod_dev;
 	};
 	__u64	user_data;	/* data to be passed back at completion time */
 	union {
@@ -145,6 +146,7 @@ enum {
 	IORING_OP_MKDIRAT,
 	IORING_OP_SYMLINKAT,
 	IORING_OP_LINKAT,
+	IORING_OP_MKNODAT,
 
 	/* this goes last, obviously */
 	IORING_OP_LAST,
-- 
2.30.2

[PATCH liburing v2 10/11] liburing.h: add mknodat prep helper

[Dmitry Kadashev]

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 src/include/liburing.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/include/liburing.h b/src/include/liburing.h
index 51dc602..c6ef0e8 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -570,6 +570,13 @@ static inline void io_uring_prep_linkat(struct io_uring_sqe *sqe, int olddfd,
 	sqe->hardlink_flags = flags;
 }
 
+static inline void io_uring_prep_mknodat(struct io_uring_sqe *sqe, int dfd,
+					const char *pathname, mode_t mode, dev_t dev)
+{
+	io_uring_prep_rw(IORING_OP_MKNODAT, sqe, dfd, pathname, mode, 0);
+	sqe->mknod_dev = dev;
+}
+
 /*
  * Returns number of unconsumed (if SQPOLL) or unsubmitted entries exist in
  * the SQ ring
-- 
2.30.2

[PATCH liburing v2 11/11] Add mknod test case

[Dmitry Kadashev]

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

Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 .gitignore    |   1 +
 test/Makefile |   2 +
 test/mknod.c  | 155 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 158 insertions(+)
 create mode 100644 test/mknod.c

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;
+}
+
-- 
2.30.2