Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / md / dm-sysfs.c

diff --git a/kernel/drivers/md/dm-sysfs.c b/kernel/drivers/md/dm-sysfs.c
new file mode 100644 (file)
index 0000000..7e818f5
--- /dev/null
+++ b/kernel/drivers/md/dm-sysfs.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/sysfs.h>
+#include <linux/dm-ioctl.h>
+#include "dm.h"
+
+struct dm_sysfs_attr {
+       struct attribute attr;
+       ssize_t (*show)(struct mapped_device *, char *);
+       ssize_t (*store)(struct mapped_device *, const char *, size_t count);
+};
+
+#define DM_ATTR_RO(_name) \
+struct dm_sysfs_attr dm_attr_##_name = \
+       __ATTR(_name, S_IRUGO, dm_attr_##_name##_show, NULL)
+
+static ssize_t dm_attr_show(struct kobject *kobj, struct attribute *attr,
+                           char *page)
+{
+       struct dm_sysfs_attr *dm_attr;
+       struct mapped_device *md;
+       ssize_t ret;
+
+       dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
+       if (!dm_attr->show)
+               return -EIO;
+
+       md = dm_get_from_kobject(kobj);
+       if (!md)
+               return -EINVAL;
+
+       ret = dm_attr->show(md, page);
+       dm_put(md);
+
+       return ret;
+}
+
+#define DM_ATTR_RW(_name) \
+struct dm_sysfs_attr dm_attr_##_name = \
+       __ATTR(_name, S_IRUGO | S_IWUSR, dm_attr_##_name##_show, dm_attr_##_name##_store)
+
+static ssize_t dm_attr_store(struct kobject *kobj, struct attribute *attr,
+                            const char *page, size_t count)
+{
+       struct dm_sysfs_attr *dm_attr;
+       struct mapped_device *md;
+       ssize_t ret;
+
+       dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
+       if (!dm_attr->store)
+               return -EIO;
+
+       md = dm_get_from_kobject(kobj);
+       if (!md)
+               return -EINVAL;
+
+       ret = dm_attr->store(md, page, count);
+       dm_put(md);
+
+       return ret;
+}
+
+static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf)
+{
+       if (dm_copy_name_and_uuid(md, buf, NULL))
+               return -EIO;
+
+       strcat(buf, "\n");
+       return strlen(buf);
+}
+
+static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf)
+{
+       if (dm_copy_name_and_uuid(md, NULL, buf))
+               return -EIO;
+
+       strcat(buf, "\n");
+       return strlen(buf);
+}
+
+static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf)
+{
+       sprintf(buf, "%d\n", dm_suspended_md(md));
+
+       return strlen(buf);
+}
+
+static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf)
+{
+       sprintf(buf, "%d\n", dm_use_blk_mq(md));
+
+       return strlen(buf);
+}
+
+static DM_ATTR_RO(name);
+static DM_ATTR_RO(uuid);
+static DM_ATTR_RO(suspended);
+static DM_ATTR_RO(use_blk_mq);
+static DM_ATTR_RW(rq_based_seq_io_merge_deadline);
+
+static struct attribute *dm_attrs[] = {
+       &dm_attr_name.attr,
+       &dm_attr_uuid.attr,
+       &dm_attr_suspended.attr,
+       &dm_attr_use_blk_mq.attr,
+       &dm_attr_rq_based_seq_io_merge_deadline.attr,
+       NULL,
+};
+
+static const struct sysfs_ops dm_sysfs_ops = {
+       .show   = dm_attr_show,
+       .store  = dm_attr_store,
+};
+
+static struct kobj_type dm_ktype = {
+       .sysfs_ops      = &dm_sysfs_ops,
+       .default_attrs  = dm_attrs,
+       .release        = dm_kobject_release,
+};
+
+/*
+ * Initialize kobj
+ * because nobody using md yet, no need to call explicit dm_get/put
+ */
+int dm_sysfs_init(struct mapped_device *md)
+{
+       return kobject_init_and_add(dm_kobject(md), &dm_ktype,
+                                   &disk_to_dev(dm_disk(md))->kobj,
+                                   "%s", "dm");
+}
+
+/*
+ * Remove kobj, called after all references removed
+ */
+void dm_sysfs_exit(struct mapped_device *md)
+{
+       struct kobject *kobj = dm_kobject(md);
+       kobject_put(kobj);
+       wait_for_completion(dm_get_completion_from_kobject(kobj));
+}