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/*
* Internal header file _only_ for device mapper core
*
* Copyright (C) 2016 Red Hat, Inc. All rights reserved.
*
* This file is released under the LGPL.
*/
#ifndef DM_CORE_INTERNAL_H
#define DM_CORE_INTERNAL_H
#include <linux/kthread.h>
#include <linux/ktime.h>
#include <linux/blk-mq.h>
#include <trace/events/block.h>
#include "dm.h"
#define DM_RESERVED_MAX_IOS 1024
struct dm_kobject_holder {
struct kobject kobj;
struct completion completion;
};
/*
* DM core internal structure that used directly by dm.c and dm-rq.c
* DM targets must _not_ deference a mapped_device to directly access its members!
*/
struct mapped_device {
struct srcu_struct io_barrier;
struct mutex suspend_lock;
/*
* The current mapping (struct dm_table *).
* Use dm_get_live_table{_fast} or take suspend_lock for
* dereference.
*/
void __rcu *map;
struct list_head table_devices;
struct mutex table_devices_lock;
unsigned long flags;
struct request_queue *queue;
int numa_node_id;
enum dm_queue_mode type;
/* Protect queue and type against concurrent access. */
struct mutex type_lock;
atomic_t holders;
atomic_t open_count;
struct dm_target *immutable_target;
struct target_type *immutable_target_type;
struct gendisk *disk;
char name[16];
void *interface_ptr;
/*
* A list of ios that arrived while we were suspended.
*/
atomic_t pending[2];
wait_queue_head_t wait;
struct work_struct work;
spinlock_t deferred_lock;
struct bio_list deferred;
/*
* Event handling.
*/
wait_queue_head_t eventq;
atomic_t event_nr;
atomic_t uevent_seq;
struct list_head uevent_list;
spinlock_t uevent_lock; /* Protect access to uevent_list */
/* the number of internal suspends */
unsigned internal_suspend_count;
/*
* Processing queue (flush)
*/
struct workqueue_struct *wq;
/*
* io objects are allocated from here.
*/
mempool_t *io_pool;
struct bio_set *bs;
/*
* freeze/thaw support require holding onto a super block
*/
struct super_block *frozen_sb;
/* forced geometry settings */
struct hd_geometry geometry;
struct block_device *bdev;
/* kobject and completion */
struct dm_kobject_holder kobj_holder;
/* zero-length flush that will be cloned and submitted to targets */
struct bio flush_bio;
struct dm_stats stats;
struct kthread_worker kworker;
struct task_struct *kworker_task;
/* for request-based merge heuristic in dm_request_fn() */
unsigned seq_rq_merge_deadline_usecs;
int last_rq_rw;
sector_t last_rq_pos;
ktime_t last_rq_start_time;
/* for blk-mq request-based DM support */
struct blk_mq_tag_set *tag_set;
bool use_blk_mq:1;
bool init_tio_pdu:1;
};
void dm_init_md_queue(struct mapped_device *md);
void dm_init_normal_md_queue(struct mapped_device *md);
int md_in_flight(struct mapped_device *md);
void disable_write_same(struct mapped_device *md);
void disable_write_zeroes(struct mapped_device *md);
static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
{
return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
}
unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
{
return !maxlen || strlen(result) + 1 >= maxlen;
}
#endif
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