open_posix_testsuite/mmap_11-4: Skip this test on tmpfs

Message ID 1533102620-30244-1-git-send-email-yangx.jy@cn.fujitsu.com
State Accepted
Delegated to: Petr Vorel
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Series
  • open_posix_testsuite/mmap_11-4: Skip this test on tmpfs
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Commit Message

Xiao Yang Aug. 1, 2018, 5:50 a.m.
According to mmap(2) manpage, when you write data to such partial
page after the end of the object, the data stays in the page cache
even after the file is closed and unmapped, subsequent mappings
always see the modified content on tmpfs.  We just skip this test
when running it on tmpfs.

Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
---
 .../conformance/interfaces/mmap/11-4.c                    | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Comments

Petr Vorel Aug. 27, 2018, 10:48 p.m. | #1
Hi Xiao,
> According to mmap(2) manpage, when you write data to such partial
> page after the end of the object, the data stays in the page cache
> even after the file is closed and unmapped, subsequent mappings
> always see the modified content on tmpfs.  We just skip this test
> when running it on tmpfs.

> Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>

> ---
>  .../conformance/interfaces/mmap/11-4.c                    | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)

> diff --git a/testcases/open_posix_testsuite/conformance/interfaces/mmap/11-4.c b/testcases/open_posix_testsuite/conformance/interfaces/mmap/11-4.c
> index 2b44815..a52b288 100644
> --- a/testcases/open_posix_testsuite/conformance/interfaces/mmap/11-4.c
> +++ b/testcases/open_posix_testsuite/conformance/interfaces/mmap/11-4.c
> @@ -40,8 +40,11 @@
>  #include <fcntl.h>
>  #include <string.h>
>  #include <errno.h>
> +#include <sys/vfs.h>
>  #include "posixtest.h"

> +#define TYPE_TMPFS_MAGIC	0x01021994

Thanks for your patch, pushed.

I don't like redefinition of TMPFS_MAGIC, but I didn't change it as openposix
subproject don't use include directory from root and therefore we can't use
TST_TMPFS_MAGIC from tst_fs.h. And I didn't add include of <linux/magic.h>
due the same inaccessibility of config.h.
Maybe it'd make sense to make access for some of the headers from include
directory.


Kind regards,
Petr

Patch

diff --git a/testcases/open_posix_testsuite/conformance/interfaces/mmap/11-4.c b/testcases/open_posix_testsuite/conformance/interfaces/mmap/11-4.c
index 2b44815..a52b288 100644
--- a/testcases/open_posix_testsuite/conformance/interfaces/mmap/11-4.c
+++ b/testcases/open_posix_testsuite/conformance/interfaces/mmap/11-4.c
@@ -40,8 +40,11 @@ 
 #include <fcntl.h>
 #include <string.h>
 #include <errno.h>
+#include <sys/vfs.h>
 #include "posixtest.h"
 
+#define TYPE_TMPFS_MAGIC	0x01021994
+
 int main(void)
 {
 	char tmpfname[256];
@@ -54,11 +57,23 @@  int main(void)
 	pid_t child;
 	int i, exit_val;
 
+	struct statfs buf;
+
 	page_size = sysconf(_SC_PAGE_SIZE);
 
 	/* mmap will create a partial page */
 	len = page_size / 2;
 
+	if (statfs("/tmp", &buf)) {
+		printf("Error at statfs(): %s\n", strerror(errno));
+		return PTS_UNRESOLVED;
+	}
+
+	if (buf.f_type == TYPE_TMPFS_MAGIC) {
+		printf("From mmap(2) manpage, skip known bug on tmpfs\n");
+		return PTS_UNTESTED;
+	}
+
 	snprintf(tmpfname, sizeof(tmpfname), "/tmp/pts_mmap_11_5_%d", getpid());
 	child = fork();
 	switch (child) {