ltrack_stats.c

来自「lustre 1.6.5 source code」· C语言 代码 · 共 494 行 · 第 1/2 页

                        }
                }
                /* closing popen for llstat */
                if (pclose(fp_popen) < 0) {
                        fprintf(stderr, "Error: Couldn't pclos"
                                " llstat popen call\n");
                        exit(1);
                }
        } /* child ends */
        return pid_llstat_command;
}

pid_t fork_actual_command(int type, unsigned short id, char* stats_path,
                          char* command)
{
        pid_t pid;

        /* starting ltrack_stats functionality here */
        if ((pid = fork()) < 0)
                fprintf(stderr, "Error: Fork error\n");

        /* fork for executing command */
        if (pid == 0) {
                switch(type) {
                        case TRACK_BY_GID:
                                if (setgid(id) < 0) {
                                        fprintf(stderr, "Error: failed to"
                                               " setgid\n");
                                        exit(1);
                                }
                                pid = id;
                                break;

                        case TRACK_BY_PID:
                        case TRACK_BY_PPID:
                                pid = getpid();
                                break;

                        /* 0 has to be written to vfs_track_pid to collect 
                         * statistics of all processes */
                        case TRACK_FOR_ALL:
                                pid = 0;
                                type = TRACK_BY_PID;
                                break;
                }
                write_track_xid(type, pid, stats_path);
                execl("/bin/sh", "sh", "-c", command, (char *)0);
                exit(0);
        } /* child ends */

        return(pid);
}

char* get_path_stats(int with_llstat, char* stats_path)
{
        glob_t stats_glob_buffer;
        int choice;
        char error = 0;
        int i;

        /* No slots reserved in gl_pathv. Store the found path at 0 location */
        stats_glob_buffer.gl_offs = 0;

        /* doing glob() for attaching llstat to monitor each vfs_ops_stat for
         * mulitiple lustre clients */
        if (glob("/proc/fs/lustre/llite/*", GLOB_DOOFFS, NULL,
                 &stats_glob_buffer) != 0) {
                fprintf(stderr,"Error: Couldn't find /proc entry for "
                        "lustre\n");
                exit(1);
        }

        /* If multiple client entries found in /proc/fs/lustre/llite user will
         * be prompted with choice of all */
        if (stats_glob_buffer.gl_pathc > 1 && with_llstat) {
                check_llstat(); 
                printf("Multiple lustre clients found, continuing... \n");
                do {
                        /* If flow is here again it means there was an error
                         * and notifying that to user */
                        if (error) {
                                system("clear");
                                fprintf(stderr, "Error: Please give correct "
                                        "choice.\n");
                        }
                        /* Simple menu based interface to avoid possible
                         * spelling mistakes */
                        printf("\t\tMenu.\n");
                        for (i = 0; i < stats_glob_buffer.gl_pathc; i++)
                                printf("\t\t%d. %s\n", i+1, 
                                       stats_glob_buffer.gl_pathv[i]);

                        printf("\nEnter the lustre client number you want to "
                               "use:");
                        scanf(" %d", &choice);
                        error ++;
                } while (choice > stats_glob_buffer.gl_pathc || choice < 1);
                strcpy(stats_path, stats_glob_buffer.gl_pathv[choice - 1]);
        } else {
                /*if only one client then simply copying the path from glob */
                strcpy(stats_path, stats_glob_buffer.gl_pathv[0]);
        }
        /* this frees dynamically allocated space by glob() for storing found
         * paths */
        globfree(&stats_glob_buffer);

        return stats_path;
}

/* Writes the id (gid/ pid/ ppid) value in appropriate tracking proc entry file
 * and EXECs the command given */
void fork_command(int type, unsigned short id, char* command, char* llstat_file)
{
        pid_t pid_actual_command = 0;
        pid_t pid_llstat_command = 0;

        /* counters */
        int with_llstat = 1;
        int status;
        char stats_path[1024];
        char stats_path_temp[1024];

        if (strlen(llstat_file) == 0)
                with_llstat = 0;

        get_path_stats(with_llstat, stats_path);
        strcpy(stats_path_temp, stats_path);

        /* llstat process attached to monitor given command */
        if (with_llstat)
                pid_llstat_command = fork_llstat_command(llstat_file,
                                                         stats_path_temp);

        /* forking a process which will exec command given */
        pid_actual_command = fork_actual_command(type, id, stats_path,
                                                 command);

        if (waitpid(pid_actual_command, NULL, 0) != pid_actual_command)
                fprintf(stderr, "Error: waitpid error\n");

        if (with_llstat) {
                /* comment #25 of BUG 10968 */
                sleep(2); 

                /* sending kill to all llstat commands created for each
                 * lustre-client respectively */
                kill(pid_llstat_command, 9);
                waitpid(pid_llstat_command, &status, 0);

                /* if llstat child is killed by KILL only then print note for
                 * plotting graph and if its exited normally with errornous
                 * status then it means there were some error and llstat was
                 * aborted*/
                if (!WIFEXITED(status))
                        printf("\n\t[Note: Do \"$plot-llstat %s\" to plot a graph"
                               " using GNU plot]\n", llstat_file);

        }
}

/* main */
int main(int argc, char **argv)
{
        char gid_string[5] = "";
        gid_t gid;
        int c;
        char command[COMM_LEN] = "";
        char llstat_file[100] = "";

        /* Checking for root*/
        if (getuid()) {
                fprintf(stderr, "Error: You need to be root\n");
                exit(1);
        }

        opterr = 0;
        /* Parsing command line switches */
        while ((c = getopt(argc, argv, "l:g:c:i:a:h")) != 1)
                switch (c) {
                        case 'l':
                                strcpy(llstat_file, optarg);
                                if (strlen(llstat_file) > LEN_OUT) {
                                        fprintf(stderr, "length of outfile file"
                                                " is too long\n");
                                        exit(1);
                                }
                                break;

                        /* When any value is written to vfs_track_gid, then VFS
                         * operation statistics are collected for all
                         * processes of that group ID.
                         * write_track_xid writes given <gid> in vfs_track_gid
                         * here. */
                        case 'g':
                                strcpy(gid_string, optarg);
                                get_command_from_argv(optind, argc, argv, "",
                                                      command);
                                gid = atoi(gid_string);

                                fork_command(TRACK_BY_GID, gid, command,
                                             llstat_file); 
                                return(0);

                        /* When any value is written to vfs_track_ppid, then VFS
                         * operation statistics are collected for all processes
                         * whose parents' PID is same as track_ppid.
                         *- write_track_xid writes pid to vfs_track_ppid here */
                        case 'c':
                                get_command_from_argv(optind, argc, argv,
                                                      optarg, command);
                                fork_command(TRACK_BY_PPID, 0, command,
                                             llstat_file);
                                return(0);

                        /* When a non-zero value is written to vfs_track_pid,
                         * then VFS operation statistics are collected for only
                         * that PID.Write_track_xid writes pid to vfs_track_pid
                         * here.Wei need to FORK a new process and EXEC it with
                         * given <command>. */
                        case 'i':
                                get_command_from_argv(optind, argc, argv,
                                                      optarg, command);
                                fork_command(TRACK_BY_PID, 0, command,
                                             llstat_file);
                                return(0);

                        /* When VFS operation statistics for all processes are
                         * to be collected, "0" is written to vfs_track_pid. */
                        case 'a':
                                get_command_from_argv(optind, argc, argv,
                                                      optarg, command);
                                fork_command(TRACK_FOR_ALL, 0, command,
                                             llstat_file);
                                return(0);

                        /* Help */
                        case 'h':
                                print_usage();
                                return(0);

                        default:
                                print_usage();
                                return(1);
                }
        return(0);
} /* main ends */