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);
+}