xref: /dragonfly/sbin/hammer/cmd_abort.c (revision a3127495)
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 	while ((den = readdir(dir)) != NULL) {
70 		if (strncmp(den->d_name, prefix, pflen) == 0) {
71 			snprintf (pidfile, PIDFILE_BUFSIZE, "%s/%s",
72 				pidfile_loc, den->d_name);
73 			pid = strtol((char *)(den->d_name + pflen), &str, 10);
74 			pf_fd = open(pidfile, O_RDONLY | O_CLOEXEC);
75 			if (pf_fd == -1)
76 				continue;
77 
78 			if (flock(pf_fd, LOCK_EX | LOCK_NB) < 0) {
79 				if (errno == EWOULDBLOCK) {
80 					/* error expected during cleanup */
81 					if (kill (pid, SIGTERM) == 0)
82 						printf (termmsg, pid);
83 				}
84 			} else {
85 				/* lock succeeded so pidfile is stale */
86 				flock (pf_fd, LOCK_UN);
87 			}
88 			close (pf_fd);
89 			unlink (pidfile);
90 		}
91 	}
92 	closedir(dir);
93 }
94