fs/ocfs2/cluster/sys.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * sys.c
   5  *
   6  * OCFS2 cluster sysfs interface
   7  *
   8  * Copyright (C) 2005 Oracle.  All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation,
  13  * version 2 of the License.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public
  21  * License along with this program; if not, write to the
  22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23  * Boston, MA 021110-1307, USA.
  24  *
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/kobject.h>
  30 #include <linux/sysfs.h>
  31
  32 #include "ocfs2_nodemanager.h"
  33 #include "masklog.h"
  34 #include "sys.h"
  35
  36 struct o2cb_attribute {
  37         struct attribute        attr;
  38         ssize_t (*show)(char *buf);
  39         ssize_t (*store)(const char *buf, size_t count);
  40 };
  41
  42 #define O2CB_ATTR(_name, _mode, _show, _store)  \
  43 struct o2cb_attribute o2cb_attr_##_name = __ATTR(_name, _mode, _show, _store)
  44
  45 #define to_o2cb_subsys(k) container_of(to_kset(k), struct subsystem, kset)
  46 #define to_o2cb_attr(_attr) container_of(_attr, struct o2cb_attribute, attr)
  47
  48 static ssize_t o2cb_interface_revision_show(char *buf)
  49 {
  50         return snprintf(buf, PAGE_SIZE, "%u\n", O2NM_API_VERSION);
  51 }
  52
  53 O2CB_ATTR(interface_revision, S_IFREG | S_IRUGO, o2cb_interface_revision_show, NULL);
  54
  55 static struct attribute *o2cb_attrs[] = {
  56         &o2cb_attr_interface_revision.attr,
  57         NULL,
  58 };
  59
  60 static ssize_t
  61 o2cb_show(struct kobject * kobj, struct attribute * attr, char * buffer);
  62 static ssize_t
  63 o2cb_store(struct kobject * kobj, struct attribute * attr,
  64            const char * buffer, size_t count);
  65 static struct sysfs_ops o2cb_sysfs_ops = {
  66         .show   = o2cb_show,
  67         .store  = o2cb_store,
  68 };
  69
  70 static struct kobj_type o2cb_subsys_type = {
  71         .default_attrs  = o2cb_attrs,
  72         .sysfs_ops      = &o2cb_sysfs_ops,
  73 };
  74
  75 /* gives us o2cb_subsys */
  76 decl_subsys(o2cb, NULL, NULL);
  77
  78 static ssize_t
  79 o2cb_show(struct kobject * kobj, struct attribute * attr, char * buffer)
  80 {
  81         struct o2cb_attribute *o2cb_attr = to_o2cb_attr(attr);
  82         struct subsystem *sbs = to_o2cb_subsys(kobj);
  83
  84         BUG_ON(sbs != &o2cb_subsys);
  85
  86         if (o2cb_attr->show)
  87                 return o2cb_attr->show(buffer);
  88         return -EIO;
  89 }
  90
  91 static ssize_t
  92 o2cb_store(struct kobject * kobj, struct attribute * attr,
  93              const char * buffer, size_t count)
  94 {
  95         struct o2cb_attribute *o2cb_attr = to_o2cb_attr(attr);
  96         struct subsystem *sbs = to_o2cb_subsys(kobj);
  97
  98         BUG_ON(sbs != &o2cb_subsys);
  99
 100         if (o2cb_attr->store)
 101                 return o2cb_attr->store(buffer, count);
 102         return -EIO;
 103 }
 104
 105 void o2cb_sys_shutdown(void)
 106 {
 107         mlog_sys_shutdown();
 108         subsystem_unregister(&o2cb_subsys);
 109 }
 110
 111 int o2cb_sys_init(void)
 112 {
 113         int ret;
 114
 115         o2cb_subsys.kset.kobj.ktype = &o2cb_subsys_type;
 116         ret = subsystem_register(&o2cb_subsys);
 117         if (ret)
 118                 return ret;
 119
 120         ret = mlog_sys_init(&o2cb_subsys);
 121         if (ret)
 122                 subsystem_unregister(&o2cb_subsys);
 123         return ret;
 124 }