Re: [PATCH bpf 1/4] selftests: bpf: use a temporary file in test_sockmap

Martin Lau wrote:

On Thu, Jan 23, 2020 at 04:59:30PM +0000, Lorenz Bauer wrote:

quoted

Use a proper temporary file for sendpage tests. This means that running
the tests doesn't clutter the working directory, and allows running the
test on read-only filesystems.

Signed-off-by: Lorenz Bauer <redacted>
---
 tools/testing/selftests/bpf/test_sockmap.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index 4a851513c842..779e11da979c 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c

@@ -331,7 +331,7 @@ static int msg_loop_sendpage(int fd, int iov_length, int cnt,
 	FILE *file;
 	int i, fp;
 
-	file = fopen(".sendpage_tst.tmp", "w+");
+	file = tmpfile();
 	if (!file) {
 		perror("create file for sendpage");
 		return 1;

@@ -340,13 +340,8 @@ static int msg_loop_sendpage(int fd, int iov_length, int cnt,
 		fwrite(&k, sizeof(char), 1, file);
 	fflush(file);
 	fseek(file, 0, SEEK_SET);
-	fclose(file);
 
-	fp = open(".sendpage_tst.tmp", O_RDONLY);
-	if (fp < 0) {
-		perror("reopen file for sendpage");
-		return 1;
-	}
+	fp = fileno(file);

It may be better to keep fp == -1 check here.
It is not clear to me the original intention of reopen.
I would defer to John for comment.

Seeing fileno shouldn't fail seems OK to me.

quoted

 
 	clock_gettime(CLOCK_MONOTONIC, &s->start);
 	for (i = 0; i < cnt; i++) {