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, \
  71                                                               show, store)
  72
  73 ROOT_ATTR(blocks_used,  0444,   root_blocks_used_show,  NULL);
  74 ROOT_ATTR(block_limit,  0644,   root_block_limit_show,  NULL);
  75
  76 static struct attribute *btrfs_root_attrs[] = {
  77         &btrfs_root_attr_blocks_used.attr,
  78         &btrfs_root_attr_block_limit.attr,
  79         NULL,
  80 };
  81
  82 /* this is for super attrs (actual full fs) */
  83 struct btrfs_super_attr {
  84         struct attribute attr;
  85         ssize_t (*show)(struct btrfs_fs_info *, char *);
  86         ssize_t (*store)(struct btrfs_fs_info *, const char *, size_t);
  87 };
  88
  89 #define SUPER_ATTR(name, mode, show, store) \
  90 static struct btrfs_super_attr btrfs_super_attr_##name = __ATTR(name, mode, \
  91                                                                 show, store)
  92
  93 SUPER_ATTR(blocks_used,         0444,   super_blocks_used_show,         NULL);
  94 SUPER_ATTR(total_blocks,        0444,   super_total_blocks_show,        NULL);
  95 SUPER_ATTR(blocksize,           0444,   super_blocksize_show,           NULL);
  96
  97 static struct attribute *btrfs_super_attrs[] = {
  98         &btrfs_super_attr_blocks_used.attr,
  99         &btrfs_super_attr_total_blocks.attr,
 100         &btrfs_super_attr_blocksize.attr,
 101         NULL,
 102 };
 103
 104 static ssize_t btrfs_super_attr_show(struct kobject *kobj,
 105                                     struct attribute *attr, char *buf)
 106 {
 107         struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
 108                                                 super_kobj);
 109         struct btrfs_super_attr *a = container_of(attr,
 110                                                   struct btrfs_super_attr,
 111                                                   attr);
 112
 113         return a->show ? a->show(fs, buf) : 0;
 114 }
 115
 116 static ssize_t btrfs_super_attr_store(struct kobject *kobj,
 117                                      struct attribute *attr,
 118                                      const char *buf, size_t len)
 119 {
 120         struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
 121                                                 super_kobj);
 122         struct btrfs_super_attr *a = container_of(attr,
 123                                                   struct btrfs_super_attr,
 124                                                   attr);
 125
 126         return a->store ? a->store(fs, buf, len) : 0;
 127 }
 128
 129 static ssize_t btrfs_root_attr_show(struct kobject *kobj,
 130                                     struct attribute *attr, char *buf)
 131 {
 132         struct btrfs_root *root = container_of(kobj, struct btrfs_root,
 133                                                 root_kobj);
 134         struct btrfs_root_attr *a = container_of(attr,
 135                                                  struct btrfs_root_attr,
 136                                                  attr);
 137
 138         return a->show ? a->show(root, buf) : 0;
 139 }
 140
 141 static ssize_t btrfs_root_attr_store(struct kobject *kobj,
 142                                      struct attribute *attr,
 143                                      const char *buf, size_t len)
 144 {
 145         struct btrfs_root *root = container_of(kobj, struct btrfs_root,
 146                                                 root_kobj);
 147         struct btrfs_root_attr *a = container_of(attr,
 148                                                  struct btrfs_root_attr,
 149                                                  attr);
 150         return a->store ? a->store(root, buf, len) : 0;
 151 }
 152
 153 static void btrfs_super_release(struct kobject *kobj)
 154 {
 155         struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
 156                                                 super_kobj);
 157         complete(&fs->kobj_unregister);
 158 }
 159
 160 static void btrfs_root_release(struct kobject *kobj)
 161 {
 162         struct btrfs_root *root = container_of(kobj, struct btrfs_root,
 163                                                 root_kobj);
 164         complete(&root->kobj_unregister);
 165 }
 166
 167 static const struct sysfs_ops btrfs_super_attr_ops = {
 168         .show   = btrfs_super_attr_show,
 169         .store  = btrfs_super_attr_store,
 170 };
 171
 172 static const struct sysfs_ops btrfs_root_attr_ops = {
 173         .show   = btrfs_root_attr_show,
 174         .store  = btrfs_root_attr_store,
 175 };
 176
 177 static struct kobj_type btrfs_root_ktype = {
 178         .default_attrs  = btrfs_root_attrs,
 179         .sysfs_ops      = &btrfs_root_attr_ops,
 180         .release        = btrfs_root_release,
 181 };
 182
 183 static struct kobj_type btrfs_super_ktype = {
 184         .default_attrs  = btrfs_super_attrs,
 185         .sysfs_ops      = &btrfs_super_attr_ops,
 186         .release        = btrfs_super_release,
 187 };
 188
 189 /* /sys/fs/btrfs/ entry */
 190 static struct kset *btrfs_kset;
 191
 192 int btrfs_sysfs_add_super(struct btrfs_fs_info *fs)
 193 {
 194         int error;
 195         char *name;
 196         char c;
 197         int len = strlen(fs->sb->s_id) + 1;
 198         int i;
 199
 200         name = kmalloc(len, GFP_NOFS);
 201         if (!name) {
 202                 error = -ENOMEM;
 203                 goto fail;
 204         }
 205
 206         for (i = 0; i < len; i++) {
 207                 c = fs->sb->s_id[i];
 208                 if (c == '/' || c == '\\')
 209                         c = '!';
 210                 name[i] = c;
 211         }
 212         name[len] = '\0';
 213
 214         fs->super_kobj.kset = btrfs_kset;
 215         error = kobject_init_and_add(&fs->super_kobj, &btrfs_super_ktype,
 216                                      NULL, "%s", name);
 217         kfree(name);
 218         if (error)
 219                 goto fail;
 220
 221         return 0;
 222
 223 fail:
 224         printk(KERN_ERR "btrfs: sysfs creation for super failed\n");
 225         return error;
 226 }
 227
 228 int btrfs_sysfs_add_root(struct btrfs_root *root)
 229 {
 230         int error;
 231
 232         error = kobject_init_and_add(&root->root_kobj, &btrfs_root_ktype,
 233                                      &root->fs_info->super_kobj,
 234                                      "%s", root->name);
 235         if (error)
 236                 goto fail;
 237
 238         return 0;
 239
 240 fail:
 241         printk(KERN_ERR "btrfs: sysfs creation for root failed\n");
 242         return error;
 243 }
 244
 245 void btrfs_sysfs_del_root(struct btrfs_root *root)
 246 {
 247         kobject_put(&root->root_kobj);
 248         wait_for_completion(&root->kobj_unregister);
 249 }
 250
 251 void btrfs_sysfs_del_super(struct btrfs_fs_info *fs)
 252 {
 253         kobject_put(&fs->super_kobj);
 254         wait_for_completion(&fs->kobj_unregister);
 255 }
 256
 257 int btrfs_init_sysfs(void)
 258 {
 259         btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
 260         if (!btrfs_kset)
 261                 return -ENOMEM;
 262         return 0;
 263 }
 264
 265 void btrfs_exit_sysfs(void)
 266 {
 267         kset_unregister(btrfs_kset);
 268 }
 269