tests/zfs-tests/cmd/mkbusy/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 <strings.h>
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30 #include <errno.h>
  31 #include <string.h>
  32
  33 typedef enum boolean { B_FALSE, B_TRUE } boolean_t;
  34
  35 static void
  36 usage(char *progname)
  37 {
  38         (void) fprintf(stderr, "Usage: %s <dirname|filename>\n", progname);
  39         exit(1);
  40 }
  41
  42 static void
  43 fail(char *err, int rval)
  44 {
  45         perror(err);
  46         exit(rval);
  47 }
  48
  49 static void
  50 daemonize(void)
  51 {
  52         pid_t   pid;
  53
  54         if ((pid = fork()) < 0) {
  55                 fail("fork", 1);
  56         } else if (pid != 0) {
  57                 (void) fprintf(stdout, "%ld\n", (long)pid);
  58                 exit(0);
  59         }
  60
  61         (void) setsid();
  62         (void) close(0);
  63         (void) close(1);
  64         (void) close(2);
  65 }
  66
  67 int
  68 main(int argc, char *argv[])
  69 {
  70         int             ret, c;
  71         boolean_t       isdir = B_FALSE;
  72         boolean_t       fflag = B_FALSE;
  73         boolean_t       rflag = B_FALSE;
  74         struct stat     sbuf;
  75         char            *fpath = NULL;
  76         char            *prog = argv[0];
  77
  78         while ((c = getopt(argc, argv, "fr")) != -1) {
  79                 switch (c) {
  80                 /* Open the file or directory read only */
  81                 case 'r':
  82                         rflag = B_TRUE;
  83                         break;
  84                 /* Run in the foreground */
  85                 case 'f':
  86                         fflag = B_TRUE;
  87                         break;
  88                 default:
  89                         usage(prog);
  90                 }
  91         }
  92
  93         argc -= optind;
  94         argv += optind;
  95
  96         if (argc != 1)
  97                 usage(prog);
  98
  99         if ((ret = stat(argv[0], &sbuf)) != 0) {
 100                 char    *arg, *dname, *fname;
 101                 int     arglen;
 102                 char    *slash;
 103                 int     rc;
 104
 105                 /*
 106                  * The argument supplied doesn't exist. Copy the path, and
 107                  * remove the trailing slash if presnt.
 108                  */
 109                 if ((arg = strdup(argv[0])) == NULL)
 110                         fail("strdup", 1);
 111                 arglen = strlen(arg);
 112                 if (arg[arglen - 1] == '/')
 113                         arg[arglen - 1] = '\0';
 114
 115                 /*
 116                  * Get the directory and file names, using the current directory
 117                  * if the provided path doesn't specify a directory at all.
 118                  */
 119                 if ((slash = strrchr(arg, '/')) == NULL) {
 120                         dname = strdup(".");
 121                         fname = strdup(arg);
 122                 } else {
 123                         *slash = '\0';
 124                         dname = strdup(arg);
 125                         fname = strdup(slash + 1);
 126                 }
 127                 free(arg);
 128                 if (dname == NULL || fname == NULL)
 129                         fail("strdup", 1);
 130
 131                 /* The directory portion of the path must exist */
 132                 if ((ret = stat(dname, &sbuf)) != 0 || !(sbuf.st_mode &
 133                     S_IFDIR))
 134                         usage(prog);
 135
 136                 rc = asprintf(&fpath, "%s/%s", dname, fname);
 137                 free(dname);
 138                 free(fname);
 139                 if (rc == -1 || fpath == NULL)
 140                         fail("asprintf", 1);
 141
 142         } else if ((sbuf.st_mode & S_IFMT) == S_IFREG ||
 143             (sbuf.st_mode & S_IFMT) == S_IFLNK ||
 144             (sbuf.st_mode & S_IFMT) == S_IFCHR ||
 145             (sbuf.st_mode & S_IFMT) == S_IFBLK) {
 146                 fpath = strdup(argv[0]);
 147         } else if ((sbuf.st_mode & S_IFMT) == S_IFDIR) {
 148                 fpath = strdup(argv[0]);
 149                 isdir = B_TRUE;
 150         } else {
 151                 usage(prog);
 152         }
 153
 154         if (fpath == NULL)
 155                 fail("strdup", 1);
 156
 157         if (isdir == B_FALSE) {
 158                 int     fd, flags;
 159                 mode_t  mode = S_IRUSR | S_IWUSR;
 160
 161                 flags = rflag == B_FALSE ? O_CREAT | O_RDWR : O_RDONLY;
 162
 163                 if ((fd = open(fpath, flags, mode)) < 0)
 164                         fail("open", 1);
 165         } else {
 166                 DIR     *dp;
 167
 168                 if ((dp = opendir(fpath)) == NULL)
 169                         fail("opendir", 1);
 170         }
 171         free(fpath);
 172
 173         if (fflag == B_FALSE)
 174                 daemonize();
 175         (void) pause();
 176
 177         /* NOTREACHED */
 178         return (0);
 179 }