io/log_writes.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2017 Intel Corporation.
   4  * All Rights Reserved.
   5  */
   6
   7 #include "platform_defs.h"
   8 #include <libdevmapper.h>
   9 #include "command.h"
  10 #include "init.h"
  11 #include "io.h"
  12
  13 static cmdinfo_t log_writes_cmd;
  14
  15 static int
  16 mark_log(const char *device, const char *mark)
  17 {
  18         struct dm_task  *dmt;
  19         const int       size = 80;
  20         char            message[size];
  21         int             len, ret = 0;
  22
  23         len = snprintf(message, size, "mark %s", mark);
  24         if (len >= size) {
  25                 printf("mark '%s' is too long\n", mark);
  26                 return ret;
  27         }
  28
  29         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
  30                 return ret;
  31
  32         if (!dm_task_set_name(dmt, device))
  33                 goto out;
  34
  35         if (!dm_task_set_sector(dmt, 0))
  36                 goto out;
  37
  38         if (!dm_task_set_message(dmt, message))
  39                 goto out;
  40
  41         if (dm_task_run(dmt))
  42                 ret = 1;
  43 out:
  44         dm_task_destroy(dmt);
  45         return ret;
  46 }
  47
  48 static int
  49 log_writes_f(
  50         int                     argc,
  51         char                    **argv)
  52 {
  53         const char      *device = NULL;
  54         const char      *mark = NULL;
  55         int             c;
  56
  57         exitcode = 1;
  58         while ((c = getopt(argc, argv, "d:m:")) != EOF) {
  59                 switch (c) {
  60                 case 'd':
  61                         device = optarg;
  62                         break;
  63                 case 'm':
  64                         mark = optarg;
  65                         break;
  66                 default:
  67                         return command_usage(&log_writes_cmd);
  68                 }
  69         }
  70
  71         if (device == NULL || mark == NULL)
  72                 return command_usage(&log_writes_cmd);
  73
  74         if (mark_log(device, mark))
  75                 exitcode = 0;
  76
  77         return 0;
  78 }
  79
  80 void
  81 log_writes_init(void)
  82 {
  83         log_writes_cmd.name = "log_writes";
  84         log_writes_cmd.altname = "lw";
  85         log_writes_cmd.cfunc = log_writes_f;
  86         log_writes_cmd.flags = CMD_NOMAP_OK | CMD_NOFILE_OK | CMD_FOREIGN_OK
  87                                 | CMD_FLAG_ONESHOT;
  88         log_writes_cmd.argmin = 0;
  89         log_writes_cmd.argmax = -1;
  90         log_writes_cmd.args = _("-d device -m mark");
  91         log_writes_cmd.oneline =
  92                 _("create mark <mark> in the dm-log-writes log specified by <device>");
  93
  94         add_command(&log_writes_cmd);
  95 }