mirror of
https://github.com/torvalds/linux.git
synced 2024-11-06 03:51:48 +00:00
4f81a41762
The bio prison code will be useful to other future DM targets so move it to a separate module. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
73 lines
2.5 KiB
C
73 lines
2.5 KiB
C
/*
|
|
* Copyright (C) 2011-2012 Red Hat, Inc.
|
|
*
|
|
* This file is released under the GPL.
|
|
*/
|
|
|
|
#ifndef DM_BIO_PRISON_H
|
|
#define DM_BIO_PRISON_H
|
|
|
|
#include "persistent-data/dm-block-manager.h" /* FIXME: for dm_block_t */
|
|
#include "dm-thin-metadata.h" /* FIXME: for dm_thin_id */
|
|
|
|
#include <linux/list.h>
|
|
#include <linux/bio.h>
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
/*
|
|
* Sometimes we can't deal with a bio straight away. We put them in prison
|
|
* where they can't cause any mischief. Bios are put in a cell identified
|
|
* by a key, multiple bios can be in the same cell. When the cell is
|
|
* subsequently unlocked the bios become available.
|
|
*/
|
|
struct dm_bio_prison;
|
|
struct dm_bio_prison_cell;
|
|
|
|
/* FIXME: this needs to be more abstract */
|
|
struct dm_cell_key {
|
|
int virtual;
|
|
dm_thin_id dev;
|
|
dm_block_t block;
|
|
};
|
|
|
|
struct dm_bio_prison *dm_bio_prison_create(unsigned nr_cells);
|
|
void dm_bio_prison_destroy(struct dm_bio_prison *prison);
|
|
|
|
/*
|
|
* This may block if a new cell needs allocating. You must ensure that
|
|
* cells will be unlocked even if the calling thread is blocked.
|
|
*
|
|
* Returns 1 if the cell was already held, 0 if @inmate is the new holder.
|
|
*/
|
|
int dm_bio_detain(struct dm_bio_prison *prison, struct dm_cell_key *key,
|
|
struct bio *inmate, struct dm_bio_prison_cell **ref);
|
|
|
|
void dm_cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios);
|
|
void dm_cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio); // FIXME: bio arg not needed
|
|
void dm_cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates);
|
|
void dm_cell_error(struct dm_bio_prison_cell *cell);
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
/*
|
|
* We use the deferred set to keep track of pending reads to shared blocks.
|
|
* We do this to ensure the new mapping caused by a write isn't performed
|
|
* until these prior reads have completed. Otherwise the insertion of the
|
|
* new mapping could free the old block that the read bios are mapped to.
|
|
*/
|
|
|
|
struct dm_deferred_set;
|
|
struct dm_deferred_entry;
|
|
|
|
struct dm_deferred_set *dm_deferred_set_create(void);
|
|
void dm_deferred_set_destroy(struct dm_deferred_set *ds);
|
|
|
|
struct dm_deferred_entry *dm_deferred_entry_inc(struct dm_deferred_set *ds);
|
|
void dm_deferred_entry_dec(struct dm_deferred_entry *entry, struct list_head *head);
|
|
int dm_deferred_set_add_work(struct dm_deferred_set *ds, struct list_head *work);
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
#endif
|