kernel/power/tuxonice_cluster.c

   1 /*
   2  * kernel/power/tuxonice_cluster.c
   3  *
   4  * Copyright (C) 2006-2007 Nigel Cunningham (nigel at suspend2 net)
   5  *
   6  * This file is released under the GPLv2.
   7  *
   8  * This file contains routines for cluster hibernation support.
   9  *
  10  */
  11
  12 #include <linux/suspend.h>
  13 #include <linux/module.h>
  14
  15 #include "tuxonice.h"
  16 #include "tuxonice_modules.h"
  17 #include "tuxonice_sysfs.h"
  18 #include "tuxonice_io.h"
  19
  20 static char toi_cluster_master[63] = CONFIG_TOI_DEFAULT_CLUSTER_MASTER;
  21
  22 static struct toi_module_ops toi_cluster_ops;
  23
  24 /* toi_cluster_print_debug_stats
  25  *
  26  * Description: Print information to be recorded for debugging purposes into a
  27  *              buffer.
  28  * Arguments:   buffer: Pointer to a buffer into which the debug info will be
  29  *                      printed.
  30  *              size:   Size of the buffer.
  31  * Returns:     Number of characters written to the buffer.
  32  */
  33 static int toi_cluster_print_debug_stats(char *buffer, int size)
  34 {
  35         int len;
  36
  37         if (strlen(toi_cluster_master))
  38                 len = snprintf_used(buffer, size, "- Cluster master is '%s'.\n",
  39                                 toi_cluster_master);
  40         else
  41                 len = snprintf_used(buffer, size, "- Cluster support is disabled.\n");
  42         return len;
  43 }
  44
  45 /* cluster_memory_needed
  46  *
  47  * Description: Tell the caller how much memory we need to operate during
  48  *              hibernate/resume.
  49  * Returns:     Unsigned long. Maximum number of bytes of memory required for
  50  *              operation.
  51  */
  52 static int toi_cluster_memory_needed(void)
  53 {
  54         return 0;
  55 }
  56
  57 static int toi_cluster_storage_needed(void)
  58 {
  59         return 1 + strlen(toi_cluster_master);
  60 }
  61
  62 /* toi_cluster_save_config_info
  63  *
  64  * Description: Save informaton needed when reloading the image at resume time.
  65  * Arguments:   Buffer:         Pointer to a buffer of size PAGE_SIZE.
  66  * Returns:     Number of bytes used for saving our data.
  67  */
  68 static int toi_cluster_save_config_info(char *buffer)
  69 {
  70         strcpy(buffer, toi_cluster_master);
  71         return strlen(toi_cluster_master + 1);
  72 }
  73
  74 /* toi_cluster_load_config_info
  75  *
  76  * Description: Reload information needed for declustering the image at
  77  *              resume time.
  78  * Arguments:   Buffer:         Pointer to the start of the data.
  79  *              Size:           Number of bytes that were saved.
  80  */
  81 static void toi_cluster_load_config_info(char *buffer, int size)
  82 {
  83         strncpy(toi_cluster_master, buffer, size);
  84         return;
  85 }
  86
  87 /*
  88  * data for our sysfs entries.
  89  */
  90 static struct toi_sysfs_data sysfs_params[] = {
  91         {
  92                 TOI_ATTR("master", SYSFS_RW),
  93                 SYSFS_STRING(toi_cluster_master, 63, SYSFS_SM_NOT_NEEDED)
  94         },
  95
  96         {
  97                 TOI_ATTR("enabled", SYSFS_RW),
  98                 SYSFS_INT(&toi_cluster_ops.enabled, 0, 1)
  99         }
 100 };
 101
 102 /*
 103  * Ops structure.
 104  */
 105
 106 static struct toi_module_ops toi_cluster_ops = {
 107         .type                   = FILTER_MODULE,
 108         .name                   = "Cluster",
 109         .directory              = "cluster",
 110         .module                 = THIS_MODULE,
 111         .memory_needed          = toi_cluster_memory_needed,
 112         .print_debug_info       = toi_cluster_print_debug_stats,
 113         .save_config_info       = toi_cluster_save_config_info,
 114         .load_config_info       = toi_cluster_load_config_info,
 115         .storage_needed         = toi_cluster_storage_needed,
 116
 117         .sysfs_data             = sysfs_params,
 118         .num_sysfs_entries      = sizeof(sysfs_params) / sizeof(struct toi_sysfs_data),
 119 };
 120
 121 /* ---- Registration ---- */
 122
 123 #ifdef MODULE
 124 #warning Module set.
 125 #define INIT static __init
 126 #define EXIT static __exit
 127 #else
 128 #define INIT
 129 #define EXIT
 130 #endif
 131
 132 INIT int toi_cluster_init(void)
 133 {
 134         int temp = toi_register_module(&toi_cluster_ops);
 135
 136         if (!strlen(toi_cluster_master))
 137                 toi_cluster_ops.enabled = 0;
 138         return temp;
 139 }
 140
 141 EXIT void toi_cluster_exit(void)
 142 {
 143         toi_unregister_module(&toi_cluster_ops);
 144 }
 145
 146 #ifdef MODULE
 147 MODULE_LICENSE("GPL");
 148 module_init(toi_cluster_init);
 149 module_exit(toi_cluster_exit);
 150 MODULE_AUTHOR("Nigel Cunningham");
 151 MODULE_DESCRIPTION("Cluster Support for TuxOnIce");
 152 #endif