// SPDX-License-Identifier: GPL-2.0-only /* * 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-core.h" #include "dm-rq.h" struct dm_sysfs_attr { struct attribute attr; ssize_t (*show)(struct mapped_device *md, char *p); ssize_t (*store)(struct mapped_device *md, const char *p, size_t count); }; #define DM_ATTR_RO(_name) \ struct dm_sysfs_attr dm_attr_##_name = \ __ATTR(_name, 0444, 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, 0644, 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) { /* Purely for userspace compatibility */ sprintf(buf, "%d\n", true); 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, }; ATTRIBUTE_GROUPS(dm); static const struct sysfs_ops dm_sysfs_ops = { .show = dm_attr_show, .store = dm_attr_store, }; static const struct kobj_type dm_ktype = { .sysfs_ops = &dm_sysfs_ops, .default_groups = dm_groups, .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)); }