Btrfs: Add per-root block accounting and sysfs entries

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 236 insertions, 0 deletions

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index db8917e5b256..2058783373eb 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -16,6 +16,242 @@
  * 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_blocks_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_block_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_blocks_used(fs->disk_super));
+}
+
+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_blocks(fs->disk_super));
+}
+
+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_blocksize(fs->disk_super));
+}
+
+/* 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,
+};
+
+static struct kset btrfs_kset = {
+	.kobj	= {.name = "btrfs"},
+};
+
+int btrfs_sysfs_add_super(struct btrfs_fs_info *fs)
+{
+	int error;
+
+	fs->super_kobj.kset = &btrfs_kset;
+	fs->super_kobj.ktype = &btrfs_super_ktype;
+
+	error = kobject_set_name(&fs->super_kobj, "%s",
+				 fs->sb->s_id);
+	if (error)
+		goto fail;
+
+	error = kobject_register(&fs->super_kobj);
+	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;
+
+	root->root_kobj.ktype = &btrfs_root_ktype;
+	root->root_kobj.parent = &root->fs_info->super_kobj;
+
+	error = kobject_set_name(&root->root_kobj, "%s", root->name);
+	if (error) {
+		goto fail;
+	}
+
+	error = kobject_register(&root->root_kobj);
+	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_unregister(&root->root_kobj);
+	wait_for_completion(&root->kobj_unregister);
+}
+
+void btrfs_sysfs_del_super(struct btrfs_fs_info *fs)
+{
+	kobject_unregister(&fs->super_kobj);
+	wait_for_completion(&fs->kobj_unregister);
+}
+
+int btrfs_init_sysfs()
+{
+	kobj_set_kset_s(&btrfs_kset, fs_subsys);
+	return kset_register(&btrfs_kset);
+}
+
+void btrfs_exit_sysfs()
+{
+	kset_unregister(&btrfs_kset);
+}