tests/zfs-tests/cmd/mkbusy.c

   1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11
  12 /*
  13  * Copyright (c) 2012 by Delphix. All rights reserved.
  14  */
  15
  16 /*
  17  * Make a directory busy. If the argument is an existing file or directory,
  18  * simply open it directly and pause. If not, verify that the parent directory
  19  * exists, and create a new file in that directory.
  20  */
  21
  22 #include <stdio.h>
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <fcntl.h>
  26 #include <dirent.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30 #include <errno.h>
  31 #include <string.h>
  32
  33
  34 static __attribute__((noreturn)) void
  35 usage(const char *progname)
  36 {
  37         (void) fprintf(stderr, "Usage: %s <dirname|filename>\n", progname);
  38         exit(1);
  39 }
  40
  41 static __attribute__((noreturn)) void
  42 fail(const char *err)
  43 {
  44         perror(err);
  45         exit(1);
  46 }
  47
  48 static void
  49 daemonize(void)
  50 {
  51         pid_t   pid;
  52
  53         if ((pid = fork()) < 0) {
  54                 fail("fork");
  55         } else if (pid != 0) {
  56                 (void) fprintf(stdout, "%ld\n", (long)pid);
  57                 exit(0);
  58         }
  59
  60         (void) setsid();
  61         (void) close(0);
  62         (void) close(1);
  63         (void) close(2);
  64 }
  65
  66
  67 static const char *
  68 get_basename(const char *path)
  69 {
  70         const char *bn = strrchr(path, '/');
  71         return (bn ? bn + 1 : path);
  72 }
  73
  74 static ssize_t
  75 get_dirnamelen(const char *path)
  76 {
  77         const char *end = strrchr(path, '/');
  78         return (end ? end - path : -1);
  79 }
  80
  81 int
  82 main(int argc, char *argv[])
  83 {
  84         int             c;
  85         boolean_t       isdir = B_FALSE;
  86         struct stat     sbuf;
  87         char            *fpath = NULL;
  88         char            *prog = argv[0];
  89
  90         while ((c = getopt(argc, argv, "")) != -1) {
  91                 switch (c) {
  92                 default:
  93                         usage(prog);
  94                 }
  95         }
  96
  97         argc -= optind;
  98         argv += optind;
  99
 100         if (argc != 1)
 101                 usage(prog);
 102
 103         if (stat(argv[0], &sbuf) != 0) {
 104                 char    *arg;
 105                 const char      *dname, *fname;
 106                 size_t  arglen;
 107                 ssize_t dnamelen;
 108
 109                 /*
 110                  * The argument supplied doesn't exist. Copy the path, and
 111                  * remove the trailing slash if present.
 112                  */
 113                 if ((arg = strdup(argv[0])) == NULL)
 114                         fail("strdup");
 115                 arglen = strlen(arg);
 116                 if (arg[arglen - 1] == '/')
 117                         arg[arglen - 1] = '\0';
 118
 119                 /* Get the directory and file names. */
 120                 fname = get_basename(arg);
 121                 dname = arg;
 122                 if ((dnamelen = get_dirnamelen(arg)) != -1)
 123                         arg[dnamelen] = '\0';
 124                 else
 125                         dname = ".";
 126
 127                 /* The directory portion of the path must exist */
 128                 if (stat(dname, &sbuf) != 0 || !(sbuf.st_mode & S_IFDIR))
 129                         usage(prog);
 130
 131                 if (asprintf(&fpath, "%s/%s", dname, fname) == -1)
 132                         fail("asprintf");
 133
 134                 free(arg);
 135         } else
 136                 switch (sbuf.st_mode & S_IFMT) {
 137                         case S_IFDIR:
 138                                 isdir = B_TRUE;
 139                                 zfs_fallthrough;
 140                         case S_IFLNK:
 141                         case S_IFCHR:
 142                         case S_IFBLK:
 143                                 if ((fpath = strdup(argv[0])) == NULL)
 144                                         fail("strdup");
 145                                 break;
 146                         default:
 147                                 usage(prog);
 148                 }
 149
 150         if (!isdir) {
 151                 if (open(fpath, O_CREAT | O_RDWR, 0600) < 0)
 152                         fail("open");
 153         } else {
 154                 if (opendir(fpath) == NULL)
 155                         fail("opendir");
 156         }
 157         free(fpath);
 158
 159         daemonize();
 160         (void) pause();
 161
 162         return (0);
 163 }