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 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,25)
  32 static ssize_t root_blocks_used_show(struct btrfs_root *root, char *buf)
  33 {
  34         return snprintf(buf, PAGE_SIZE, "%llu\n",
  35                 (unsigned long long)btrfs_root_used(&root->root_item));
  36 }
  37
  38 static ssize_t root_block_limit_show(struct btrfs_root *root, char *buf)
  39 {
  40         return snprintf(buf, PAGE_SIZE, "%llu\n",
  41                 (unsigned long long)btrfs_root_limit(&root->root_item));
  42 }
  43
  44 static ssize_t super_blocks_used_show(struct btrfs_fs_info *fs, char *buf)
  45 {
  46
  47         return snprintf(buf, PAGE_SIZE, "%llu\n",
  48                 (unsigned long long)btrfs_super_bytes_used(&fs->super_copy));
  49 }
  50
  51 static ssize_t super_total_blocks_show(struct btrfs_fs_info *fs, char *buf)
  52 {
  53         return snprintf(buf, PAGE_SIZE, "%llu\n",
  54                 (unsigned long long)btrfs_super_total_bytes(&fs->super_copy));
  55 }
  56
  57 static ssize_t super_blocksize_show(struct btrfs_fs_info *fs, char *buf)
  58 {
  59         return snprintf(buf, PAGE_SIZE, "%llu\n",
  60                 (unsigned long long)btrfs_super_sectorsize(&fs->super_copy));
  61 }
  62
  63 /* this is for root attrs (subvols/snapshots) */
  64 struct btrfs_root_attr {
  65         struct attribute attr;
  66         ssize_t (*show)(struct btrfs_root *, char *);
  67         ssize_t (*store)(struct btrfs_root *, const char *, size_t);
  68 };
  69
  70 #define ROOT_ATTR(name, mode, show, store) \
  71 static struct btrfs_root_attr btrfs_root_attr_##name = __ATTR(name, mode, 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, show, store)
  91
  92 SUPER_ATTR(blocks_used,         0444,   super_blocks_used_show,         NULL);
  93 SUPER_ATTR(total_blocks,        0444,   super_total_blocks_show,        NULL);
  94 SUPER_ATTR(blocksize,           0444,   super_blocksize_show,           NULL);
  95
  96 static struct attribute *btrfs_super_attrs[] = {
  97         &btrfs_super_attr_blocks_used.attr,
  98         &btrfs_super_attr_total_blocks.attr,
  99         &btrfs_super_attr_blocksize.attr,
 100         NULL,
 101 };
 102
 103 static ssize_t btrfs_super_attr_show(struct kobject *kobj,
 104                                     struct attribute *attr, char *buf)
 105 {
 106         struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
 107                                                 super_kobj);
 108         struct btrfs_super_attr *a = container_of(attr,
 109                                                   struct btrfs_super_attr,
 110                                                   attr);
 111
 112         return a->show ? a->show(fs, buf) : 0;
 113 }
 114
 115 static ssize_t btrfs_super_attr_store(struct kobject *kobj,
 116                                      struct attribute *attr,
 117                                      const char *buf, size_t len)
 118 {
 119         struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
 120                                                 super_kobj);
 121         struct btrfs_super_attr *a = container_of(attr,
 122                                                   struct btrfs_super_attr,
 123                                                   attr);
 124
 125         return a->store ? a->store(fs, buf, len) : 0;
 126 }
 127
 128 static ssize_t btrfs_root_attr_show(struct kobject *kobj,
 129                                     struct attribute *attr, char *buf)
 130 {
 131         struct btrfs_root *root = container_of(kobj, struct btrfs_root,
 132                                                 root_kobj);
 133         struct btrfs_root_attr *a = container_of(attr,
 134                                                  struct btrfs_root_attr,
 135                                                  attr);
 136
 137         return a->show ? a->show(root, buf) : 0;
 138 }
 139
 140 static ssize_t btrfs_root_attr_store(struct kobject *kobj,
 141                                      struct attribute *attr,
 142                                      const char *buf, size_t len)
 143 {
 144         struct btrfs_root *root = container_of(kobj, struct btrfs_root,
 145                                                 root_kobj);
 146         struct btrfs_root_attr *a = container_of(attr,
 147                                                  struct btrfs_root_attr,
 148                                                  attr);
 149         return a->store ? a->store(root, buf, len) : 0;
 150 }
 151
 152 static void btrfs_super_release(struct kobject *kobj)
 153 {
 154         struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
 155                                                 super_kobj);
 156         complete(&fs->kobj_unregister);
 157 }
 158
 159 static void btrfs_root_release(struct kobject *kobj)
 160 {
 161         struct btrfs_root *root = container_of(kobj, struct btrfs_root,
 162                                                 root_kobj);
 163         complete(&root->kobj_unregister);
 164 }
 165
 166 static struct sysfs_ops btrfs_super_attr_ops = {
 167         .show   = btrfs_super_attr_show,
 168         .store  = btrfs_super_attr_store,
 169 };
 170
 171 static struct sysfs_ops btrfs_root_attr_ops = {
 172         .show   = btrfs_root_attr_show,
 173         .store  = btrfs_root_attr_store,
 174 };
 175
 176 static struct kobj_type btrfs_root_ktype = {
 177         .default_attrs  = btrfs_root_attrs,
 178         .sysfs_ops      = &btrfs_root_attr_ops,
 179         .release        = btrfs_root_release,
 180 };
 181
 182 static struct kobj_type btrfs_super_ktype = {
 183         .default_attrs  = btrfs_super_attrs,
 184         .sysfs_ops      = &btrfs_super_attr_ops,
 185         .release        = btrfs_super_release,
 186 };
 187
 188 /* /sys/fs/btrfs/ entry */
 189 static struct kset *btrfs_kset;
 190
 191 int btrfs_sysfs_add_super(struct btrfs_fs_info *fs)
 192 {
 193         int error;
 194         char *name;
 195         char c;
 196         int len = strlen(fs->sb->s_id) + 1;
 197         int i;
 198
 199         name = kmalloc(len, GFP_NOFS);
 200         if (!name) {
 201                 error = -ENOMEM;
 202                 goto fail;
 203         }
 204
 205         for (i = 0; i < len; i++) {
 206                 c = fs->sb->s_id[i];
 207                 if (c == '/' || c == '\\')
 208                         c = '!';
 209                 name[i] = c;
 210         }
 211         name[len] = '\0';
 212
 213         fs->super_kobj.kset = btrfs_kset;
 214         error = kobject_init_and_add(&fs->super_kobj, &btrfs_super_ktype,
 215                                      NULL, "%s", name);
 216         if (error)
 217                 goto fail;
 218
 219         kfree(name);
 220         return 0;
 221
 222 fail:
 223         kfree(name);
 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()
 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()
 266 {
 267         kset_unregister(btrfs_kset);
 268 }
 269
 270 #else
 271
 272 int btrfs_sysfs_add_super(struct btrfs_fs_info *fs)
 273 {
 274         return 0;
 275 }
 276
 277 int btrfs_sysfs_add_root(struct btrfs_root *root)
 278 {
 279         return 0;
 280 }
 281
 282 void btrfs_sysfs_del_root(struct btrfs_root *root)
 283 {
 284         return;
 285 }
 286
 287 void btrfs_sysfs_del_super(struct btrfs_fs_info *fs)
 288 {
 289         return;
 290 }
 291
 292 int btrfs_init_sysfs()
 293 {
 294         return 0;
 295 }
 296
 297 void btrfs_exit_sysfs()
 298 {
 299         return;
 300 }
 301 #endif