linux-stable/drivers/md/dm-core.h
Mike Snitzer 33bd6f0693 dm table: make 'struct dm_table' definition accessible to all of DM core
Move 'struct dm_table' definition from dm-table.c to dm-core.h and
update DM core to access its members directly.

Helps optimize max_io_len() and other methods slightly.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-09-29 16:33:07 -04:00

190 lines
4 KiB
C

/*
* 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/genhd.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 structures used directly by dm.c, dm-rq.c and dm-table.c.
* DM targets must _not_ deference a mapped_device or dm_table to directly
* access their members!
*/
struct mapped_device {
struct mutex suspend_lock;
struct mutex table_devices_lock;
struct list_head table_devices;
/*
* The current mapping (struct dm_table *).
* Use dm_get_live_table{_fast} or take suspend_lock for
* dereference.
*/
void __rcu *map;
unsigned long flags;
/* Protect queue and type against concurrent access. */
struct mutex type_lock;
enum dm_queue_mode type;
int numa_node_id;
struct request_queue *queue;
atomic_t holders;
atomic_t open_count;
struct dm_target *immutable_target;
struct target_type *immutable_target_type;
char name[16];
struct gendisk *disk;
struct dax_device *dax_dev;
/*
* A list of ios that arrived while we were suspended.
*/
struct work_struct work;
wait_queue_head_t wait;
spinlock_t deferred_lock;
struct bio_list deferred;
void *interface_ptr;
/*
* 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;
/*
* io objects are allocated from here.
*/
struct bio_set io_bs;
struct bio_set bs;
/*
* Processing queue (flush)
*/
struct workqueue_struct *wq;
/*
* freeze/thaw support require holding onto a super block
*/
struct super_block *frozen_sb;
/* forced geometry settings */
struct hd_geometry geometry;
/* kobject and completion */
struct dm_kobject_holder kobj_holder;
struct block_device *bdev;
struct dm_stats stats;
/* for blk-mq request-based DM support */
struct blk_mq_tag_set *tag_set;
bool init_tio_pdu:1;
struct srcu_struct io_barrier;
};
void disable_discard(struct mapped_device *md);
void disable_write_same(struct mapped_device *md);
void disable_write_zeroes(struct mapped_device *md);
static inline sector_t dm_get_size(struct mapped_device *md)
{
return get_capacity(md->disk);
}
static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
{
return &md->stats;
}
#define DM_TABLE_MAX_DEPTH 16
struct dm_table {
struct mapped_device *md;
enum dm_queue_mode type;
/* btree table */
unsigned int depth;
unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
sector_t *index[DM_TABLE_MAX_DEPTH];
unsigned int num_targets;
unsigned int num_allocated;
sector_t *highs;
struct dm_target *targets;
struct target_type *immutable_target_type;
bool integrity_supported:1;
bool singleton:1;
unsigned integrity_added:1;
/*
* Indicates the rw permissions for the new logical
* device. This should be a combination of FMODE_READ
* and FMODE_WRITE.
*/
fmode_t mode;
/* a list of devices used by this table */
struct list_head devices;
/* events get handed up using this callback */
void (*event_fn)(void *);
void *event_context;
struct dm_md_mempools *mempools;
};
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;
}
extern atomic_t dm_global_event_nr;
extern wait_queue_head_t dm_global_eventq;
void dm_issue_global_event(void);
#endif