[LTP] [PATCH v5 1/2] splice02: Generate input in C

[LTP] [PATCH v5 1/2] splice02: Generate input in C

[Petr Vorel]

instead relying on shell piping data into it.

Check resulted file size and content.
Also add metadata docs.

Problem found on SLES JeOS (https://progress.opensuse.org/issues/77260).

Reported-by: Martin Loviska <mloviska@suse.com>
Suggested-by: Cyril Hrubis <chrubis@suse.cz>
Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
[ chrubis: while loop simplification ]
Signed-off-by: Petr Vorel <pvorel@suse.cz>
---
Changes v4->v5:
* fix: use offset in SAFE_MMAP() to fix file checking (reported by Cyril)
Offset is required to be page size aligned.
* fix: error message wording (reported by Cyril)
* Change content to write: remove randomizing the letter and instead
write alphabet sequence 512*'a', 512*'b' ... This way error during check
due wrong offset is detected.

 runtest/smoketest                           |   2 +-
 runtest/syscalls                            |   2 +-
 testcases/kernel/syscalls/splice/splice02.c | 143 ++++++++++++++++++--
 3 files changed, 134 insertions(+), 13 deletions(-)

diff --git a/runtest/smoketest b/runtest/smoketest
index 0c24fc1fa..2224d8f74 100644
--- a/runtest/smoketest
+++ b/runtest/smoketest
@@ -11,5 +11,5 @@ symlink01 symlink01
 stat04 symlink01 -T stat04
 utime01A symlink01 -T utime01
 rename01A symlink01 -T rename01
-splice02 seq 1 20 | splice02
+splice02 splice02 -s 20
 route4-change-dst route-change-dst.sh
diff --git a/runtest/syscalls b/runtest/syscalls
index 2d1e7b648..b89c545f0 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1451,7 +1451,7 @@ socketpair02 socketpair02
 sockioctl01 sockioctl01
 
 splice01 splice01
-splice02 seq 1 20000 | splice02
+splice02 splice02
 splice03 splice03
 splice04 splice04
 splice05 splice05
diff --git a/testcases/kernel/syscalls/splice/splice02.c b/testcases/kernel/syscalls/splice/splice02.c
index b579667b9..cd7dfa836 100644
--- a/testcases/kernel/syscalls/splice/splice02.c
+++ b/testcases/kernel/syscalls/splice/splice02.c
@@ -1,40 +1,161 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) Jens Axboe <axboe@kernel.dk>, 2009
+ * Copyright (c) 2021 Petr Vorel <pvorel@suse.cz>
+ */
+
+/*\
+ * [DESCRIPTION]
+ * Original reproducer for kernel fix
+ * bf40d3435caf NFS: add support for splice writes
+ * from v2.6.31-rc1.
+ *
  * http://lkml.org/lkml/2009/4/2/55
+ *
+ * [ALGORITHM]
+ * - create pipe
+ * - fork(), child replace stdin with pipe
+ * - parent write to pipe
+ * - child slice from pipe
+ * - check resulted file size and content
  */
 
 #define _GNU_SOURCE
 
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/stat.h>
 #include <unistd.h>
-#include <fcntl.h>
 
 #include "tst_test.h"
+#include "lapi/mmap.h"
 #include "lapi/splice.h"
 
-#define SPLICE_SIZE (64*1024)
+#define BUFSIZE 512
+#define SPLICE_SIZE 1024
+
+#define TEST_FILENAME "splice02-temp"
 
-static void splice_test(void)
+static char *sarg;
+static int file_size;
+static int pipe_fd[2];
+
+static void setup(void)
+{
+	if (tst_parse_int(sarg, &file_size, 1, INT_MAX))
+		tst_brk(TBROK, "invalid number of writes '%s', use <1,%d>", sarg, INT_MAX);
+}
+
+static inline int get_letter(int n)
+{
+	return n % ('z' - 'a' + 1) + 'a';
+}
+
+static void do_child(void)
 {
 	int fd;
+	size_t size, psize, to_check, i, fail = 0;
+	struct stat st;
+	char *map;
+
+	SAFE_CLOSE(pipe_fd[1]);
+	SAFE_DUP2(pipe_fd[0], STDIN_FILENO);
 
-	fd = SAFE_OPEN("splice02-temp", O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	fd = SAFE_OPEN(TEST_FILENAME, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 
-	TEST(splice(STDIN_FILENO, NULL, fd, NULL, SPLICE_SIZE, 0));
-	if (TST_RET < 0) {
-		tst_res(TFAIL, "splice failed - errno = %d : %s",
-			TST_ERR, strerror(TST_ERR));
-	} else {
-		tst_res(TPASS, "splice() system call Passed");
+	do {
+		TEST(splice(STDIN_FILENO, NULL, fd, NULL, SPLICE_SIZE, 0));
+		if (TST_RET < 0) {
+			tst_res(TFAIL | TTERRNO, "splice failed");
+			goto cleanup;
+		}
+	} while (TST_RET > 0);
+
+	stat(TEST_FILENAME, &st);
+	if (st.st_size != file_size) {
+		tst_res(TFAIL, "file size is different from expected: %ld (%d)",
+				st.st_size, file_size);
+		return;
 	}
 
 	SAFE_CLOSE(fd);
+	fd = SAFE_OPEN(TEST_FILENAME, O_RDONLY);
+	to_check = st.st_size;
+
+	psize = sysconf(_SC_PAGESIZE);
+
+	tst_res(TINFO, "checking file content");
+	do {
+		i = 0;
+		size = to_check > psize ? psize : to_check;
+
+		map = SAFE_MMAP(NULL, size, PROT_READ, MAP_PRIVATE, fd,
+				st.st_size - to_check);
+
+		while (i < size) {
+			if (map[i] != get_letter(to_check - (i / BUFSIZE * BUFSIZE)))
+				fail++;
+			i++;
+		}
+		SAFE_MUNMAP(map, size);
+		to_check -= size;
+	} while (to_check > 0);
+
+	if (fail) {
+		tst_res(TFAIL, "%ld unexpected bytes found", fail);
+		return;
+	}
+
+	tst_res(TPASS, "splice() system call passed");
+
+cleanup:
+	SAFE_CLOSE(fd);
+	exit(0);
+}
+
+static void run(void)
+{
+	size_t size, written, max_pipe_size, to_write;
+	char buf[BUFSIZE];
+
+	SAFE_PIPE(pipe_fd);
+
+	if (!file_size) {
+		max_pipe_size = SAFE_FCNTL(pipe_fd[1], F_GETPIPE_SZ);
+		file_size = max_pipe_size << 4;
+	}
+
+	to_write = file_size;
+
+	if (!SAFE_FORK())
+		do_child();
+
+	tst_res(TINFO, "writting %d bytes", file_size);
+
+	while (to_write > 0) {
+		memset(buf, get_letter(to_write), BUFSIZE);
+
+		size = to_write > BUFSIZE ? BUFSIZE : to_write;
+		written = SAFE_WRITE(1, pipe_fd[1], &buf, size);
+		to_write -= written;
+	}
+
+	SAFE_CLOSE(pipe_fd[0]);
+	SAFE_CLOSE(pipe_fd[1]);
+
+	tst_reap_children();
 }
 
 static struct tst_test test = {
-	.test_all = splice_test,
+	.test_all = run,
+	.setup = setup,
+	.needs_checkpoints = 1,
 	.needs_tmpdir = 1,
+	.forks_child = 1,
 	.min_kver = "2.6.17",
+	.options = (struct tst_option[]) {
+		{"s:", &sarg, "-s x     Size of output file in bytes (default: 16x max pipe size, i.e. 1M on intel)"},
+		{}
+	},
 };
-- 
2.31.1

[LTP] [PATCH v5 2/2] commands: Add shell pipe test

[Petr Vorel]

This adds basic shell pipe testing, which was removed from splice02
in 85cebe238 ("splice02: Generate input in C").

Suggested-by: Cyril Hrubis <chrubis@suse.cz>
Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
Signed-off-by: Petr Vorel <pvorel@suse.cz>
---
The same as v4.

 runtest/commands                         |  1 +
 runtest/smoketest                        |  1 +
 testcases/commands/shell/Makefile        | 10 ++++++++++
 testcases/commands/shell/shell_pipe01.sh | 17 +++++++++++++++++
 4 files changed, 29 insertions(+)
 create mode 100644 testcases/commands/shell/Makefile
 create mode 100755 testcases/commands/shell/shell_pipe01.sh

diff --git a/runtest/commands b/runtest/commands
index 058266b54..8cfad0449 100644
--- a/runtest/commands
+++ b/runtest/commands
@@ -41,3 +41,4 @@ gdb01_sh gdb01.sh
 unshare01_sh unshare01.sh
 sysctl01_sh sysctl01.sh
 sysctl02_sh sysctl02.sh
+shell_test01 echo "SUCCESS" | shell_pipe01.sh
diff --git a/runtest/smoketest b/runtest/smoketest
index 2224d8f74..7f395936e 100644
--- a/runtest/smoketest
+++ b/runtest/smoketest
@@ -13,3 +13,4 @@ utime01A symlink01 -T utime01
 rename01A symlink01 -T rename01
 splice02 splice02 -s 20
 route4-change-dst route-change-dst.sh
+shell_test01 echo "SUCCESS" | shell_pipe01.sh
diff --git a/testcases/commands/shell/Makefile b/testcases/commands/shell/Makefile
new file mode 100644
index 000000000..c696ec35a
--- /dev/null
+++ b/testcases/commands/shell/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) Linux Test Project, 2021
+
+top_srcdir		?= ../../..
+
+include $(top_srcdir)/include/mk/env_pre.mk
+
+INSTALL_TARGETS		:= *.sh
+
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/commands/shell/shell_pipe01.sh b/testcases/commands/shell/shell_pipe01.sh
new file mode 100755
index 000000000..3c8ef49fb
--- /dev/null
+++ b/testcases/commands/shell/shell_pipe01.sh
@@ -0,0 +1,17 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2021 Petr Vorel <pvorel@suse.cz>
+
+TST_TESTFUNC=do_test
+
+. tst_test.sh
+
+do_test()
+{
+	tst_res TINFO "expecting SUCCESS string passed from stdin"
+
+	read line
+	EXPECT_PASS [ "$line" = "SUCCESS" ]
+}
+
+tst_run
-- 
2.31.1

[LTP] [PATCH v5 1/2] splice02: Generate input in C

[Cyril Hrubis]

Hi!
>  	SAFE_CLOSE(fd);
> +	fd = SAFE_OPEN(TEST_FILENAME, O_RDONLY);
> +	to_check = st.st_size;
> +
> +	psize = sysconf(_SC_PAGESIZE);
> +
> +	tst_res(TINFO, "checking file content");
> +	do {
> +		i = 0;
> +		size = to_check > psize ? psize : to_check;
> +
> +		map = SAFE_MMAP(NULL, size, PROT_READ, MAP_PRIVATE, fd,
> +				st.st_size - to_check);

Huh, why do we loop backward over the file?

Maybe we can just do simple loop here that would be easier to
understand:

	blocks = LTP_ALIGN(st.st_size, page_size) / page_size;

	for (block = 0; block < blocks; block++) {
		map = SAFE_MMAP(NULL, pagesize, PROT_READ, MAP_PRIVATE, fd, block * pagesize);

		to_check = (block+1) * page_size < st.st_size ? page_size : st.st_size % page_size;

		for (i = 0; i < to_check; i++) {
			if (map[i] != get_letter(block * page_size + i))
				fail++;
		}

		SAFE_MUNMAP(map, size);
	}

[Beware I haven't tested the code :-)]

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [PATCH v5 1/2] splice02: Generate input in C

[Petr Vorel]

> Hi!
> >  	SAFE_CLOSE(fd);
> > +	fd = SAFE_OPEN(TEST_FILENAME, O_RDONLY);
> > +	to_check = st.st_size;
> > +
> > +	psize = sysconf(_SC_PAGESIZE);
> > +
> > +	tst_res(TINFO, "checking file content");
> > +	do {
> > +		i = 0;
> > +		size = to_check > psize ? psize : to_check;
> > +
> > +		map = SAFE_MMAP(NULL, size, PROT_READ, MAP_PRIVATE, fd,
> > +				st.st_size - to_check);

> Huh, why do we loop backward over the file?

> Maybe we can just do simple loop here that would be easier to
> understand:

> 	blocks = LTP_ALIGN(st.st_size, page_size) / page_size;

> 	for (block = 0; block < blocks; block++) {
> 		map = SAFE_MMAP(NULL, pagesize, PROT_READ, MAP_PRIVATE, fd, block * pagesize);

> 		to_check = (block+1) * page_size < st.st_size ? page_size : st.st_size % page_size;

> 		for (i = 0; i < to_check; i++) {
> 			if (map[i] != get_letter(block * page_size + i))
> 				fail++;
> 		}

> 		SAFE_MUNMAP(map, size);
> 	}

> [Beware I haven't tested the code :-)]
Yep. In your code you expect that written letter change each time.
But original code writes the same letter for whole buffer (using memset()).

I guess it does not matter whether I keep writing with memset() as is
and adapt the checking code (code you proposed) or if I use your code for
checking and adapt writing code: create buffer 494 (19x 26 letters), memset() it
only once. Or do you have any preference of these?

Also I have to replace 2x return with goto cleanup (to close fd and exit the child).

Kind regards,
Petr

[LTP] [PATCH v5 1/2] splice02: Generate input in C

[Cyril Hrubis]

Hi!
> Yep. In your code you expect that written letter change each time.
> But original code writes the same letter for whole buffer (using memset()).

Ah, right, the mapping in the original code maps the remaning size to be
written to a letter and uses it for whole block.

I guess that it may be easier to understand if the letter was defined as
an function of a position in the file like I have expected in my
snippet. That way we can also produce different patterns without
changing the test code (and we can later on introduce a library
functions to fill buffer and check buffer as well, these would generally
take a pointer to a buffer, size and an offset).

That would mean that we will have to fill the buffer in a for loop
instead of memset, but as long as the get_letter() function is inlined
it should be fast enough.

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [PATCH v5 1/2] splice02: Generate input in C

[Petr Vorel]

Hi Cyril,

> Hi!
> > Yep. In your code you expect that written letter change each time.
> > But original code writes the same letter for whole buffer (using memset()).

> Ah, right, the mapping in the original code maps the remaning size to be
> written to a letter and uses it for whole block.

> I guess that it may be easier to understand if the letter was defined as
> an function of a position in the file like I have expected in my
> snippet. That way we can also produce different patterns without
> changing the test code (and we can later on introduce a library
> functions to fill buffer and check buffer as well, these would generally
> take a pointer to a buffer, size and an offset).
Make sense.

> That would mean that we will have to fill the buffer in a for loop
> instead of memset, but as long as the get_letter() function is inlined
> it should be fast enough.
Right. I guess trying to "align" buffer with alphabet size (e.g. multiple of 26)
to avoid filling the buffer is not worth. Thus I keep buffer size 512 and fill
it each time.

Thanks for your suggestions and time.

Kind regards,
Petr