fs/btrfs/sysfs.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/completion.h>
  23 #include <linux/buffer_head.h>
  24 #include <linux/module.h>
  25 #include <linux/kobject.h>
  26
  27 #include "ctree.h"
  28 #include "disk-io.h"
  29 #include "transaction.h"
  30
  31 static ssize_t root_blocks_used_show(struct btrfs_root *root, char *buf)
  32 {
  33         return snprintf(buf, PAGE_SIZE, "%llu\n",
  34                 (unsigned long long)btrfs_root_used(&root->root_item));
  35 }
  36
  37 static ssize_t root_block_limit_show(struct btrfs_root *root, char *buf)
  38 {
  39         return snprintf(buf, PAGE_SIZE, "%llu\n",
  40                 (unsigned long long)btrfs_root_limit(&root->root_item));
  41 }
  42
  43 static ssize_t super_blocks_used_show(struct btrfs_fs_info *fs, char *buf)
  44 {
  45
  46         return snprintf(buf, PAGE_SIZE, "%llu\n",
  47                 (unsigned long long)btrfs_super_bytes_used(&fs->super_copy));
  48 }
  49
  50 static ssize_t super_total_blocks_show(struct btrfs_fs_info *fs, char *buf)
  51 {
  52         return snprintf(buf, PAGE_SIZE, "%llu\n",
  53                 (unsigned long long)btrfs_super_total_bytes(&fs->super_copy));
  54 }
  55
  56 static ssize_t super_blocksize_show(struct btrfs_fs_info *fs, char *buf)
  57 {
  58         return snprintf(buf, PAGE_SIZE, "%llu\n",
  59                 (unsigned long long)btrfs_super_sectorsize(&fs->super_copy));
  60 }
  61
  62 /* this is for root attrs (subvols/snapshots) */
  63 struct btrfs_root_attr {
  64         struct attribute attr;
  65         ssize_t (*show)(struct btrfs_root *, char *);
  66         ssize_t (*store)(struct btrfs_root *, const char *, size_t);
  67 };
  68
  69 #define ROOT_ATTR(name, mode, show, store) \
  70 static struct btrfs_root_attr btrfs_root_attr_##name = __ATTR(name, mode, show, store)
  71
  72 ROOT_ATTR(blocks_used,  0444,   root_blocks_used_show,  NULL);
  73 ROOT_ATTR(block_limit,  0644,   root_block_limit_show,  NULL);
  74
  75 static struct attribute *btrfs_root_attrs[] = {
  76         &btrfs_root_attr_blocks_used.attr,
  77         &btrfs_root_attr_block_limit.attr,
  78         NULL,
  79 };
  80
  81 /* this is for super attrs (actual full fs) */
  82 struct btrfs_super_attr {
  83         struct attribute attr;
  84         ssize_t (*show)(struct btrfs_fs_info *, char *);
  85         ssize_t (*store)(struct btrfs_fs_info *, const char *, size_t);
  86 };
  87
  88 #define SUPER_ATTR(name, mode, show, store) \
  89 static struct btrfs_super_attr btrfs_super_attr_##name = __ATTR(name, mode, show, store)
  90
  91 SUPER_ATTR(blocks_used,         0444,   super_blocks_used_show,         NULL);
  92 SUPER_ATTR(total_blocks,        0444,   super_total_blocks_show,        NULL);
  93 SUPER_ATTR(blocksize,           0444,   super_blocksize_show,           NULL);
  94
  95 static struct attribute *btrfs_super_attrs[] = {
  96         &btrfs_super_attr_blocks_used.attr,
  97         &btrfs_super_attr_total_blocks.attr,
  98         &btrfs_super_attr_blocksize.attr,
  99         NULL,
 100 };
 101
 102 static ssize_t btrfs_super_attr_show(struct kobject *kobj,
 103                                     struct attribute *attr, char *buf)
 104 {
 105         struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
 106                                                 super_kobj);
 107         struct btrfs_super_attr *a = container_of(attr,
 108                                                   struct btrfs_super_attr,
 109                                                   attr);
 110
 111         return a->show ? a->show(fs, buf) : 0;
 112 }
 113
 114 static ssize_t btrfs_super_attr_store(struct kobject *kobj,
 115                                      struct attribute *attr,
 116                                      const char *buf, size_t len)
 117 {
 118         struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
 119                                                 super_kobj);
 120         struct btrfs_super_attr *a = container_of(attr,
 121                                                   struct btrfs_super_attr,
 122                                                   attr);
 123
 124         return a->store ? a->store(fs, buf, len) : 0;
 125 }
 126
 127 static ssize_t btrfs_root_attr_show(struct kobject *kobj,
 128                                     struct attribute *attr, char *buf)
 129 {
 130         struct btrfs_root *root = container_of(kobj, struct btrfs_root,
 131                                                 root_kobj);
 132         struct btrfs_root_attr *a = container_of(attr,
 133                                                  struct btrfs_root_attr,
 134                                                  attr);
 135
 136         return a->show ? a->show(root, buf) : 0;
 137 }
 138
 139 static ssize_t btrfs_root_attr_store(struct kobject *kobj,
 140                                      struct attribute *attr,
 141                                      const char *buf, size_t len)
 142 {
 143         struct btrfs_root *root = container_of(kobj, struct btrfs_root,
 144                                                 root_kobj);
 145         struct btrfs_root_attr *a = container_of(attr,
 146                                                  struct btrfs_root_attr,
 147                                                  attr);
 148         return a->store ? a->store(root, buf, len) : 0;
 149 }
 150
 151 static void btrfs_super_release(struct kobject *kobj)
 152 {
 153         struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
 154                                                 super_kobj);
 155         complete(&fs->kobj_unregister);
 156 }
 157
 158 static void btrfs_root_release(struct kobject *kobj)
 159 {
 160         struct btrfs_root *root = container_of(kobj, struct btrfs_root,
 161                                                 root_kobj);
 162         complete(&root->kobj_unregister);
 163 }
 164
 165 static struct sysfs_ops btrfs_super_attr_ops = {
 166         .show   = btrfs_super_attr_show,
 167         .store  = btrfs_super_attr_store,
 168 };
 169
 170 static struct sysfs_ops btrfs_root_attr_ops = {
 171         .show   = btrfs_root_attr_show,
 172         .store  = btrfs_root_attr_store,
 173 };
 174
 175 static struct kobj_type btrfs_root_ktype = {
 176         .default_attrs  = btrfs_root_attrs,
 177         .sysfs_ops      = &btrfs_root_attr_ops,
 178         .release        = btrfs_root_release,
 179 };
 180
 181 static struct kobj_type btrfs_super_ktype = {
 182         .default_attrs  = btrfs_super_attrs,
 183         .sysfs_ops      = &btrfs_super_attr_ops,
 184         .release        = btrfs_super_release,
 185 };
 186
 187 static struct kset btrfs_kset;
 188
 189 int btrfs_sysfs_add_super(struct btrfs_fs_info *fs)
 190 {
 191         int error;
 192         char *name;
 193         char c;
 194         int len = strlen(fs->sb->s_id) + 1;
 195         int i;
 196
 197         name = kmalloc(len, GFP_NOFS);
 198         if (!name) {
 199                 error = -ENOMEM;
 200                 goto fail;
 201         }
 202
 203         for (i = 0; i < len; i++) {
 204                 c = fs->sb->s_id[i];
 205                 if (c == '/' || c == '\\')
 206                         c = '!';
 207                 name[i] = c;
 208         }
 209         name[len] = '\0';
 210
 211         fs->super_kobj.kset = &btrfs_kset;
 212         fs->super_kobj.ktype = &btrfs_super_ktype;
 213
 214         error = kobject_set_name(&fs->super_kobj, "%s", name);
 215         if (error)
 216                 goto fail;
 217
 218         error = kobject_register(&fs->super_kobj);
 219         if (error)
 220                 goto fail;
 221
 222         kfree(name);
 223         return 0;
 224
 225 fail:
 226         kfree(name);
 227         printk(KERN_ERR "btrfs: sysfs creation for super failed\n");
 228         return error;
 229 }
 230
 231 int btrfs_sysfs_add_root(struct btrfs_root *root)
 232 {
 233         int error;
 234
 235         root->root_kobj.ktype = &btrfs_root_ktype;
 236         root->root_kobj.parent = &root->fs_info->super_kobj;
 237
 238         error = kobject_set_name(&root->root_kobj, "%s", root->name);
 239         if (error) {
 240                 goto fail;
 241         }
 242
 243         error = kobject_register(&root->root_kobj);
 244         if (error)
 245                 goto fail;
 246
 247         return 0;
 248
 249 fail:
 250         printk(KERN_ERR "btrfs: sysfs creation for root failed\n");
 251         return error;
 252 }
 253
 254 void btrfs_sysfs_del_root(struct btrfs_root *root)
 255 {
 256         kobject_unregister(&root->root_kobj);
 257         wait_for_completion(&root->kobj_unregister);
 258 }
 259
 260 void btrfs_sysfs_del_super(struct btrfs_fs_info *fs)
 261 {
 262         kobject_unregister(&fs->super_kobj);
 263         wait_for_completion(&fs->kobj_unregister);
 264 }
 265
 266 int btrfs_init_sysfs()
 267 {
 268         kobj_set_kset_s(&btrfs_kset, fs_subsys);
 269         kobject_set_name(&btrfs_kset.kobj, "btrfs");
 270         return kset_register(&btrfs_kset);
 271 }
 272
 273 void btrfs_exit_sysfs()
 274 {
 275         kset_unregister(&btrfs_kset);
 276 }