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

From: Shuah Khan
Date: Fri Mar 13 2015 - 09:47:08 EST


On 03/13/2015 03:34 AM, Andrew Vagin wrote:
> 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.

Please send a properly marked patch v2. Please don't
send patches as attachments.

thanks,
-- Shuah
>
>>
>> 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


--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@xxxxxxxxxxxxxxx | (970) 217-8978
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