Btrfs had plans to export key information sysfs. In general this
isn't used today and may soon go away.
Signed-off-by: Chris Mason <chris.mason@xxxxxxxxxx>
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
new file mode 100644
index 0000000..a240b6f
--- /dev/null
+++ b/fs/btrfs/sysfs.c
@@ -0,0 +1,269 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+
+static ssize_t root_blocks_used_show(struct btrfs_root *root, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_root_used(&root->root_item));
+}
+
+static ssize_t root_block_limit_show(struct btrfs_root *root, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_root_limit(&root->root_item));
+}
+
+static ssize_t super_blocks_used_show(struct btrfs_fs_info *fs, char *buf)
+{
+
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_super_bytes_used(&fs->super_copy));
+}
+
+static ssize_t super_total_blocks_show(struct btrfs_fs_info *fs, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_super_total_bytes(&fs->super_copy));
+}
+
+static ssize_t super_blocksize_show(struct btrfs_fs_info *fs, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)btrfs_super_sectorsize(&fs->super_copy));
+}
+
+/* this is for root attrs (subvols/snapshots) */
+struct btrfs_root_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct btrfs_root *, char *);
+ ssize_t (*store)(struct btrfs_root *, const char *, size_t);
+};
+
+#define ROOT_ATTR(name, mode, show, store) \
+static struct btrfs_root_attr btrfs_root_attr_##name = __ATTR(name, mode, \
+ show, store)
+
+ROOT_ATTR(blocks_used, 0444, root_blocks_used_show, NULL);
+ROOT_ATTR(block_limit, 0644, root_block_limit_show, NULL);
+
+static struct attribute *btrfs_root_attrs[] = {
+ &btrfs_root_attr_blocks_used.attr,
+ &btrfs_root_attr_block_limit.attr,
+ NULL,
+};
+
+/* this is for super attrs (actual full fs) */
+struct btrfs_super_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct btrfs_fs_info *, char *);
+ ssize_t (*store)(struct btrfs_fs_info *, const char *, size_t);
+};
+
+#define SUPER_ATTR(name, mode, show, store) \
+static struct btrfs_super_attr btrfs_super_attr_##name = __ATTR(name, mode, \
+ show, store)
+
+SUPER_ATTR(blocks_used, 0444, super_blocks_used_show, NULL);
+SUPER_ATTR(total_blocks, 0444, super_total_blocks_show, NULL);
+SUPER_ATTR(blocksize, 0444, super_blocksize_show, NULL);
+
+static struct attribute *btrfs_super_attrs[] = {
+ &btrfs_super_attr_blocks_used.attr,
+ &btrfs_super_attr_total_blocks.attr,
+ &btrfs_super_attr_blocksize.attr,
+ NULL,
+};
+
+static ssize_t btrfs_super_attr_show(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
+ super_kobj);
+ struct btrfs_super_attr *a = container_of(attr,
+ struct btrfs_super_attr,
+ attr);
+
+ return a->show ? a->show(fs, buf) : 0;
+}
+
+static ssize_t btrfs_super_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf, size_t len)
+{
+ struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
+ super_kobj);
+ struct btrfs_super_attr *a = container_of(attr,
+ struct btrfs_super_attr,
+ attr);
+
+ return a->store ? a->store(fs, buf, len) : 0;
+}
+
+static ssize_t btrfs_root_attr_show(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct btrfs_root *root = container_of(kobj, struct btrfs_root,
+ root_kobj);
+ struct btrfs_root_attr *a = container_of(attr,
+ struct btrfs_root_attr,
+ attr);
+
+ return a->show ? a->show(root, buf) : 0;
+}
+
+static ssize_t btrfs_root_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf, size_t len)
+{
+ struct btrfs_root *root = container_of(kobj, struct btrfs_root,
+ root_kobj);
+ struct btrfs_root_attr *a = container_of(attr,
+ struct btrfs_root_attr,
+ attr);
+ return a->store ? a->store(root, buf, len) : 0;
+}
+
+static void btrfs_super_release(struct kobject *kobj)
+{
+ struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
+ super_kobj);
+ complete(&fs->kobj_unregister);
+}
+
+static void btrfs_root_release(struct kobject *kobj)
+{
+ struct btrfs_root *root = container_of(kobj, struct btrfs_root,
+ root_kobj);
+ complete(&root->kobj_unregister);
+}
+
+static struct sysfs_ops btrfs_super_attr_ops = {
+ .show = btrfs_super_attr_show,
+ .store = btrfs_super_attr_store,
+};
+
+static struct sysfs_ops btrfs_root_attr_ops = {
+ .show = btrfs_root_attr_show,
+ .store = btrfs_root_attr_store,
+};
+
+static struct kobj_type btrfs_root_ktype = {
+ .default_attrs = btrfs_root_attrs,
+ .sysfs_ops = &btrfs_root_attr_ops,
+ .release = btrfs_root_release,
+};
+
+static struct kobj_type btrfs_super_ktype = {
+ .default_attrs = btrfs_super_attrs,
+ .sysfs_ops = &btrfs_super_attr_ops,
+ .release = btrfs_super_release,
+};
+
+/* /sys/fs/btrfs/ entry */
+static struct kset *btrfs_kset;
+
+int btrfs_sysfs_add_super(struct btrfs_fs_info *fs)
+{
+ int error;
+ char *name;
+ char c;
+ int len = strlen(fs->sb->s_id) + 1;
+ int i;
+
+ name = kmalloc(len, GFP_NOFS);
+ if (!name) {
+ error = -ENOMEM;
+ goto fail;
+ }
+
+ for (i = 0; i < len; i++) {
+ c = fs->sb->s_id[i];
+ if (c == '/' || c == '\\')
+ c = '!';
+ name[i] = c;
+ }
+ name[len] = '\0';
+
+ fs->super_kobj.kset = btrfs_kset;
+ error = kobject_init_and_add(&fs->super_kobj, &btrfs_super_ktype,
+ NULL, "%s", name);
+ kfree(name);
+ if (error)
+ goto fail;
+
+ return 0;
+
+fail:
+ printk(KERN_ERR "btrfs: sysfs creation for super failed\n");
+ return error;
+}
+
+int btrfs_sysfs_add_root(struct btrfs_root *root)
+{
+ int error;
+
+ error = kobject_init_and_add(&root->root_kobj, &btrfs_root_ktype,
+ &root->fs_info->super_kobj,
+ "%s", root->name);
+ if (error)
+ goto fail;
+
+ return 0;
+
+fail:
+ printk(KERN_ERR "btrfs: sysfs creation for root failed\n");
+ return error;
+}
+
+void btrfs_sysfs_del_root(struct btrfs_root *root)
+{
+ kobject_put(&root->root_kobj);
+ wait_for_completion(&root->kobj_unregister);
+}
+
+void btrfs_sysfs_del_super(struct btrfs_fs_info *fs)
+{
+ kobject_put(&fs->super_kobj);
+ wait_for_completion(&fs->kobj_unregister);
+}
+
+int btrfs_init_sysfs(void)
+{
+ btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
+ if (!btrfs_kset)
+ return -ENOMEM;
+ return 0;
+}
+
+void btrfs_exit_sysfs(void)
+{
+ kset_unregister(btrfs_kset);
+}
+
--
1.6.0.2
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