Merge branch 'at_empty_path' of https://github.com/charliemirabile/li…

…buring

* 'at_empty_path' of https://github.com/charliemirabile/liburing:
  test/hardlink: Add test for `AT_EMPTY_PATH` flag
  test/hardlink: introduce `fd` variable to hold the file open file descriptor
  test/hardlink: add parameter for old's dirfd to `do_linkat`
  test/hardlink: Cleanup error handling

test/hardlink.c

@@ -12,7 +12,7 @@
 #include "liburing.h"
 #include "helpers.h"
 
-static int do_linkat(struct io_uring *ring, const char *oldname,
+static int do_linkat(struct io_uring *ring, int olddirfd, const char *oldname,
 		     const char *newname, int flags)
 {
 	struct io_uring_sqe *sqe;
@@ -24,7 +24,7 @@ static int do_linkat(struct io_uring *ring, const char *oldname,
 		fprintf(stderr, "sqe get failed\n");
 		return 1;
 	}
-	io_uring_prep_linkat(sqe, AT_FDCWD, oldname, AT_FDCWD, newname, flags);
+	io_uring_prep_linkat(sqe, olddirfd, oldname, AT_FDCWD, newname, flags);
 
 	ret = io_uring_submit(ring);
 	if (ret != 1) {
@@ -68,10 +68,11 @@ static int files_linked_ok(const char* fn1, const char *fn2)
 int main(int argc, char *argv[])
 {
 	static const char target[] = "io_uring-linkat-test-target";
+	static const char emptyname[] = "io_uring-linkat-test-empty";
 	static const char linkname[] = "io_uring-linkat-test-link";
 	static const char symlinkname[] = "io_uring-linkat-test-symlink";
 	struct io_uring ring;
-	int ret;
+	int ret, fd, exit_status = T_EXIT_FAIL;
 
 	if (argc > 1)
 		return T_EXIT_SKIP;
@@ -82,81 +83,88 @@ int main(int argc, char *argv[])
 		return ret;
 	}
 
-	ret = open(target, O_CREAT | O_RDWR | O_EXCL, 0600);
+	ret = fd = open(target, O_CREAT | O_RDWR | O_EXCL, 0600);
 	if (ret < 0) {
 		perror("open");
-		goto err;
+		goto out;
+	}
+	if (write(fd, "linktest", 8) != 8) {
+		close(fd);
+		goto out;
 	}
-	if (write(ret, "linktest", 8) != 8) {
-		close(ret);
-		goto err1;
+	if(geteuid()) {
+		fprintf(stdout, "not root, skipping AT_EMPTY_PATH test\n");
+	} else {
+		ret = do_linkat(&ring, fd, "", emptyname, AT_EMPTY_PATH);
+		if (ret < 0) {
+			if (ret == -EBADF || ret == -EINVAL) {
+				fprintf(stdout, "linkat not supported, skipping\n");
+				exit_status = T_EXIT_SKIP;
+				goto out;
+			}
+			fprintf(stderr, "linkat: %s\n", strerror(-ret));
+			goto out;
+		} else if (ret) {
+			goto out;
+		}
+		if (!files_linked_ok(emptyname, target))
+			goto out;
+		unlinkat(AT_FDCWD, emptyname, 0);
 	}
-	close(ret);
+	close(fd);
 
 	ret = symlink(target, symlinkname);
 	if (ret < 0) {
 		perror("open");
-		goto err1;
+		goto out;
 	}
 
-	ret = do_linkat(&ring, target, linkname, 0);
+	ret = do_linkat(&ring, AT_FDCWD, target, linkname, 0);
 	if (ret < 0) {
 		if (ret == -EBADF || ret == -EINVAL) {
 			fprintf(stdout, "linkat not supported, skipping\n");
-			goto skip;
+			exit_status = T_EXIT_SKIP;
+			goto out;
 		}
 		fprintf(stderr, "linkat: %s\n", strerror(-ret));
-		goto err2;
+		goto out;
 	} else if (ret) {
-		goto err2;
+		goto out;
 	}
 
 	if (!files_linked_ok(linkname, target))
-		goto err3;
+		goto out;
 
 	unlinkat(AT_FDCWD, linkname, 0);
 
-	ret = do_linkat(&ring, symlinkname, linkname, AT_SYMLINK_FOLLOW);
+	ret = do_linkat(&ring, AT_FDCWD, symlinkname, linkname, AT_SYMLINK_FOLLOW);
 	if (ret < 0) {
 		fprintf(stderr, "linkat: %s\n", strerror(-ret));
-		goto err2;
+		goto out;
 	} else if (ret) {
-		goto err2;
+		goto out;
 	}
 
 	if (!files_linked_ok(symlinkname, target))
-		goto err3;
+		goto out;
 
-	ret = do_linkat(&ring, target, linkname, 0);
+	ret = do_linkat(&ring, AT_FDCWD, target, linkname, 0);
 	if (ret != -EEXIST) {
 		fprintf(stderr, "test_linkat linkname already exists failed: %d\n", ret);
-		goto err3;
+		goto out;
 	}
 
-	ret = do_linkat(&ring, target, "surely/this/does/not/exist", 0);
+	ret = do_linkat(&ring, AT_FDCWD, target, "surely/this/does/not/exist", 0);
 	if (ret != -ENOENT) {
 		fprintf(stderr, "test_linkat no parent failed: %d\n", ret);
-		goto err3;
+		goto out;
 	}
-
-	unlinkat(AT_FDCWD, symlinkname, 0);
-	unlinkat(AT_FDCWD, linkname, 0);
-	unlinkat(AT_FDCWD, target, 0);
-	io_uring_queue_exit(&ring);
-	return T_EXIT_PASS;
-skip:
+	exit_status = T_EXIT_PASS;
+out:
 	unlinkat(AT_FDCWD, symlinkname, 0);
 	unlinkat(AT_FDCWD, linkname, 0);
+	unlinkat(AT_FDCWD, emptyname, 0);
 	unlinkat(AT_FDCWD, target, 0);
 	io_uring_queue_exit(&ring);
-	return T_EXIT_SKIP;
-err3:
-	unlinkat(AT_FDCWD, linkname, 0);
-err2:
-	unlinkat(AT_FDCWD, symlinkname, 0);
-err1:
-	unlinkat(AT_FDCWD, target, 0);
-err:
-	io_uring_queue_exit(&ring);
-	return T_EXIT_FAIL;
+	return exit_status;
 }