sbin/hammer/cmd_abort.c

   1 /*
   2  * Copyright (c) 2015 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by John Marino <draco@marino.st>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34 /*
  35  * Each "hammer cleanup" command creates a pid file at /var/run with the
  36  * name hammer.cleanup.$pid with the contents of $pid
  37  *
  38  * If the cleanup ends without incident, the pid file is removed.  If the
  39  * cleanup job is interrupted, the pid file is not removed.  This is
  40  * because SIGINT is disabled in deferrence to HAMMER ioctl.
  41  *
  42  * The "hammer abort-cleanup" command is simple.  It scans /var/run for
  43  * all files starting with "hammer.cleanup.", reads them, and issues a
  44  * SIGINTR for any valid pid.  Every hammer.cleanup.XXXXXX file will be
  45  * removed after the command executes.  If multiple cleanup jobs are
  46  * running simultaneously, all of them will be aborted.
  47  *
  48  * It is intended any future "abort" commands are also placed in here.
  49  */
  50
  51 #include "hammer.h"
  52
  53 void
  54 hammer_cmd_abort_cleanup(char **av __unused, int ac __unused)
  55 {
  56         DIR *dir;
  57         pid_t pid;
  58         char *str;
  59         int pf_fd;
  60         struct dirent *den;
  61         static char pidfile[PIDFILE_BUFSIZE];
  62         static const char prefix[] = "hammer.cleanup.";
  63         static const char termmsg[] = "Terminated cleanup process %u\n";
  64         const size_t pflen = sizeof(prefix) - 1;
  65
  66         if ((dir = opendir(pidfile_loc)) == NULL) {
  67                 return;
  68         }
  69
  70         while ((den = readdir(dir)) != NULL) {
  71                 if (strncmp(den->d_name, prefix, pflen) == 0) {
  72                         snprintf (pidfile, PIDFILE_BUFSIZE, "%s/%s",
  73                                 pidfile_loc, den->d_name);
  74                         pid = strtol((char *)(den->d_name + pflen), &str, 10);
  75                         pf_fd = open(pidfile, O_RDONLY | O_CLOEXEC);
  76                         if (pf_fd == -1) {
  77                                 continue;
  78                         }
  79
  80                         if (flock(pf_fd, LOCK_EX | LOCK_NB) < 0) {
  81                                 if (errno == EWOULDBLOCK) {
  82                                         /* error expected during cleanup */
  83                                         if (kill (pid, SIGTERM) == 0) {
  84                                                 printf (termmsg, pid);
  85                                         }
  86                                 }
  87                         }
  88                         else {
  89                                 /* lock succeeded so pidfile is stale */
  90                                 flock (pf_fd, LOCK_UN);
  91                         }
  92                         close (pf_fd);
  93                         unlink (pidfile);
  94                 }
  95         }
  96         closedir(dir);
  97 }