Re: [PATCH] selftest: add a test case to check how locks are shown in fdinfo

[Andrew Vagin]

 On Thu, Mar 12, 2015 at 02:43:19PM -0600, Shuah Khan wrote:
> Hi Andrey,
> 
> Looks good in general. Couple of comments.

Thanks. The updated version is attached.

> 
> On 03/12/2015 10:30 AM, Andrey Vagin wrote:
> > The main idea of this test is to check that locks are shown correctly
> > when they can't be placed in a default seq_file buffer due to its size.
> > 
> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
> > Signed-off-by: Andrey Vagin <avagin@xxxxxxxxxx>
> > ---
> >  tools/testing/selftests/Makefile        |   1 +
> >  tools/testing/selftests/fdinfo/Makefile |  11 +++
> >  tools/testing/selftests/fdinfo/locks.c  | 119 ++++++++++++++++++++++++++++++++
> >  3 files changed, 131 insertions(+)
> >  create mode 100644 tools/testing/selftests/fdinfo/Makefile
> >  create mode 100644 tools/testing/selftests/fdinfo/locks.c
> > 
> > diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> > index 4e51122..8cd57f6 100644
> > --- a/tools/testing/selftests/Makefile
> > +++ b/tools/testing/selftests/Makefile
> > @@ -17,6 +17,7 @@ TARGETS += sysctl
> >  TARGETS += timers
> >  TARGETS += user
> >  TARGETS += vm
> > +TARGETS += fdinfo
> >  #Please keep the TARGETS list alphabetically sorted
> 
> Please move the new target up to keep the TARGETS list
> alphabetically sorted. This helps avoid conflicts as new
> tests get added.
> 
> >  
> >  TARGETS_HOTPLUG = cpu-hotplug
> > diff --git a/tools/testing/selftests/fdinfo/Makefile b/tools/testing/selftests/fdinfo/Makefile
> > new file mode 100644
> > index 0000000..83f34ef
> > --- /dev/null
> > +++ b/tools/testing/selftests/fdinfo/Makefile
> > @@ -0,0 +1,11 @@
> > +CFLAGS += -Wall
> > +
> > +all: locks
> > +
> > +run_tests: all
> > +	@./locks || echo "locks: [FAIL]"
> > +
> > +locks: locks.c
> > +
> > +clean:
> > +	rm -f locks
> > diff --git a/tools/testing/selftests/fdinfo/locks.c b/tools/testing/selftests/fdinfo/locks.c
> > new file mode 100644
> > index 0000000..93f25c6
> > --- /dev/null
> > +++ b/tools/testing/selftests/fdinfo/locks.c
> > @@ -0,0 +1,119 @@
> > +#include <stdlib.h>
> > +#include <stdio.h>
> > +#include <unistd.h>
> > +#include <string.h>
> > +#include <sys/types.h>
> > +#include <sys/stat.h>
> > +#include <fcntl.h>
> > +
> > +#define pr_perror(fmt, ...) fprintf(stderr, "%s:%d: " fmt ": %m\n", \
> > +					__FILE__, __LINE__, ##__VA_ARGS__)
> > +
> > +#define FILE_SIZE 4096
> > +
> > +int main(int argc, char **argv)
> > +{
> > +	int fd, fdinfo, i, ret, size, bsize = 4096;
> > +	char *buf, *p, fdinfo_path[] = "/proc/self/fdinfo/XXXXXXXXXX";
> > +
> > +	fd = open("test_file", O_RDWR | O_CREAT, 0666);
> > +	if (fd == -1) {
> > +		pr_perror("Unable to open test_file");
> > +		return 1;
> > +	}
> > +	unlink("test_file");
> > +	if (ftruncate(fd, FILE_SIZE) == -1) {
> > +		pr_perror("Unable to truncate test_file");
> > +		return 1;
> > +	}
> > +
> > +	/*
> > +	 * Generate FILE_SIZE locks. We are going to exceed the default
> > +	 * size of seq buffer
> > +	 */
> > +	for (i = 0; i < FILE_SIZE; i++) {
> > +		struct flock lock;
> > +
> > +		if (i % 2)
> > +			lock.l_type = F_WRLCK;
> > +		else
> > +			lock.l_type = F_RDLCK;
> > +		lock.l_whence = SEEK_SET;
> > +		lock.l_start  = i;
> > +		lock.l_len    = 1;
> > +		lock.l_pid    = -1;
> > +		if (fcntl(fd, F_SETLK, &lock)) {
> > +			pr_perror("Unable to set lock %d\n", i);
> > +			return 1;
> > +		}
> > +	}
> > +
> > +	snprintf(fdinfo_path, sizeof(fdinfo_path), "/proc/self/fdinfo/%d", fd);
> > +	fdinfo = open(fdinfo_path, O_RDONLY);
> > +	if (fdinfo < 0) {
> > +		pr_perror("Unable to open %s", fdinfo_path);
> > +		return 1;
> > +	}
> > +
> > +	buf = malloc(bsize);
> > +	if (buf == NULL) {
> > +		pr_perror("Unable to allocate a buffer");
> > +		return 1;
> > +	}
> > +	size = 0;
> > +	while (1) {
> > +		ret = read(fdinfo, buf + size, bsize - 1 - size);
> > +		if (ret == 0)
> > +			break;
> > +		if (ret == -1) {
> > +			pr_perror("Unable to read %s", fdinfo_path);
> > +			return 1;
> > +		}
> > +		size += ret;
> > +		if (bsize - size < 4096)
> > +			bsize += 4096;
> > +		buf = realloc(buf, bsize);
> > +		if (buf == NULL) {
> > +			pr_perror("Unable to allocate a buffer");
> > +			return 1;
> > +		}
> > +	}
> > +	buf[size] = 0;
> > +
> > +	i = 0;
> > +	for (p = buf - 1; p != NULL; p = strchr(p, '\n')) {
> > +		char fl_flag[10], fl_type[15], fl_option[10], end[32];
> > +		int fl_id, fl_owner, maj, min;
> > +		unsigned long ino;
> > +		unsigned long long start;
> > +
> > +		p++;
> > +
> > +		if (strncmp(p, "lock:", 5))
> > +			continue;
> > +		ret = sscanf(p, "lock:\t%d:%s %s %s %d %x:%x:%ld %lld %s",
> > +				&fl_id, fl_flag, fl_type, fl_option,
> > +				&fl_owner, &maj, &min, &ino,
> > +				&start, end);
> > +		if (ret != 10) {
> > +			pr_perror("Unable to parse");
> > +			fprintf(stderr, "%s\n", buf);
> > +			return 1;
> > +		}
> > +		i++;
> > +	}
> > +
> > +	close(fdinfo);
> > +	close(fd);
> > +
> > +	if (i == FILE_SIZE)
> > +		printf("PASS\n");
> 
> Look into using ksft framework for reporting pass/fail conditions.
> Please see kselftest.h for the framework.
> 
> > +	else {
> > +		fprintf(stderr, "%s\n", buf);
> > +		return 1;
> > +	}
> > +
> > +	free(buf);
> > +
> > +	return 0;
> > +}
> > 
> 
> thanks,
> -- Shuah
> 
> -- 
> Shuah Khan
> Sr. Linux Kernel Developer
> Open Source Innovation Group
> Samsung Research America (Silicon Valley)
> shuahkh@xxxxxxxxxxxxxxx | (970) 217-8978