ping_pong: add -l option

Add a new option -l to check whether POSIX byte range locks are
working. Usage:

node1$ touch /path/to/cluster-fs/FILE

node1$ ./bin/ping_pong -l /path/to/cluster-fs/FILE
Holding lock, press any key to continue...
You should run the same command on another node now.

node2$ ./bin/ping_pong -l /path/to/cluster-fs/FILE

Output can either be:

  Holding lock, press any key to continue...

This means POSIX byte range locks are *not* working.

If you see this instead:

  file already locked, calling check_lock to tell us who has it locked...:
  check_lock failed: lock held: pid='27375', type='1', start='0', len='0'
  Working POSIX byte range locks

Congrats, you have a cluster fs with functional byte range locks!

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Thu Dec 10 08:48:38 CET 2015 on sn-devel-104

(Imported from commit 2f16675a2294c8197ad45862c3e8a4fa2061d2e9)

diff --git a/utils/ping_pong/ping_pong.c b/utils/ping_pong/ping_pong.c
index fdb575daae29c305c12d978024e01b32580f53bc..be43a1d704d24c3043cf4a402bb3a16899275293 100644 (file)
--- a/utils/ping_pong/ping_pong.c
+++ b/utils/ping_pong/ping_pong.c
@@ -39,10 +39,11 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/mman.h>
+#include <stdbool.h>
 
 static struct timeval tp1,tp2;
 
-static int do_reads, do_writes, use_mmap, do_check;
+static int do_reads, do_writes, use_mmap, do_check, do_brl_test;
 
 static void start_timer(void)
 {
@@ -57,7 +58,7 @@ static double end_timer(void)
 }
 
 /* lock a byte range in a open file */
-static int lock_range(int fd, int offset, int len)
+static int lock_range(int fd, int offset, int len, bool wait)
 {
        struct flock lock;
 
@@ -67,7 +68,7 @@ static int lock_range(int fd, int offset, int len)
        lock.l_len = len;
        lock.l_pid = 0;
        
-       return fcntl(fd,F_SETLKW,&lock);
+       return fcntl(fd, wait ? F_SETLKW : F_SETLK, &lock);
 }
 
 /* check whether we could place a lock */
@@ -147,11 +148,11 @@ static void ping_pong(int fd, int num_locks)
 
        start_timer();
 
-       lock_range(fd, 0, 1);
+       lock_range(fd, 0, 1, true);
        i = 0;
 
        while (1) {
-               if (lock_range(fd, (i+1) % num_locks, 1) != 0) {
+               if (lock_range(fd, (i+1) % num_locks, 1, true) != 0) {
                        printf("lock at %d failed! - %s\n",
                               (i+1) % num_locks, strerror(errno));
                }
@@ -198,13 +199,25 @@ static void ping_pong(int fd, int num_locks)
        }
 }
 
+static void usage(void)
+{
+       printf("ping_pong -rwmc <file> <num_locks>\n");
+       printf("ping_pong -l <file>\n\n");
+       printf("Options\n");
+       printf(" -r    do reads\n");
+       printf(" -w    do writes\n");
+       printf(" -m    use mmap\n");
+       printf(" -c    check locks\n");
+       printf(" -l    test for working byte range locks\n");
+}
+
 int main(int argc, char *argv[])
 {
        char *fname;
        int fd, num_locks;
        int c;
 
-       while ((c = getopt(argc, argv, "rwmc")) != -1) {
+       while ((c = getopt(argc, argv, "rwmcl")) != -1) {
                switch (c){
                case 'w':
                        do_writes = 1;
@@ -218,6 +231,9 @@ int main(int argc, char *argv[])
                case 'c':
                        do_check = 1;
                        break;
+               case 'l':
+                       do_brl_test = 1;
+                       break;
                default:
                        fprintf(stderr, "Unknown option '%c'\n", c);
                        exit(1);
@@ -227,25 +243,44 @@ int main(int argc, char *argv[])
        argv += optind;
        argc -= optind;
 
-       if (argc < 2) {
-               printf("ping_pong [options] <file> <num_locks>\n");
-               printf("           -r    do reads\n");
-               printf("           -w    do writes\n");
-               printf("           -m    use mmap\n");
-               printf("           -c    check locks\n");
+       if (argc < 1) {
+               usage();
                exit(1);
        }
 
        fname = argv[0];
+
+       fd = open(fname, O_CREAT|O_RDWR, 0600);
+       if (fd == -1) {
+               exit(1);
+       }
+
+       if (do_brl_test) {
+               if (lock_range(fd, 0, 0, false) != 0) {
+                       printf("file already locked, calling check_lock to tell us who has it locked:\n");
+                       (void)check_lock(fd, 0, 0);
+                       printf("Working POSIX byte range locks\n");
+                       exit(0);
+               }
+
+               printf("Holding lock, press any key to continue...\n");
+               printf("You should run the same command on another node now.\n");
+               getchar();
+               printf("Good bye.\n");
+               exit(0);
+       }
+
+       if (argc < 2) {
+               usage();
+               exit(1);
+       }
+
        num_locks = atoi(argv[1]);
        if (num_locks <= 0) {
                printf("num_locks should be > 0\n");
                exit(1);
        }
 
-       fd = open(fname, O_CREAT|O_RDWR, 0600);
-       if (fd == -1) exit(1);
-
        ping_pong(fd, num_locks);
 
        return 0;