linux/drivers/md/dm-zoned-reclaim.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2017 Western Digital Corporation or its affiliates.
 *
 * This file is released under the GPL.
 */

#include "dm-zoned.h"

#include <linux/module.h>

#define DM_MSG_PREFIX …

struct dmz_reclaim { … };

/*
 * Reclaim state flags.
 */
enum { … };

/*
 * Number of seconds of target BIO inactivity to consider the target idle.
 */
#define DMZ_IDLE_PERIOD …

/*
 * Percentage of unmapped (free) random zones below which reclaim starts
 * even if the target is busy.
 */
#define DMZ_RECLAIM_LOW_UNMAP_ZONES …

/*
 * Percentage of unmapped (free) random zones above which reclaim will
 * stop if the target is busy.
 */
#define DMZ_RECLAIM_HIGH_UNMAP_ZONES …

/*
 * Align a sequential zone write pointer to chunk_block.
 */
static int dmz_reclaim_align_wp(struct dmz_reclaim *zrc, struct dm_zone *zone,
				sector_t block)
{ … }

/*
 * dm_kcopyd_copy end notification.
 */
static void dmz_reclaim_kcopy_end(int read_err, unsigned long write_err,
				  void *context)
{ … }

/*
 * Copy valid blocks of src_zone into dst_zone.
 */
static int dmz_reclaim_copy(struct dmz_reclaim *zrc,
			    struct dm_zone *src_zone, struct dm_zone *dst_zone)
{ … }

/*
 * Move valid blocks of dzone buffer zone into dzone (after its write pointer)
 * and free the buffer zone.
 */
static int dmz_reclaim_buf(struct dmz_reclaim *zrc, struct dm_zone *dzone)
{ … }

/*
 * Merge valid blocks of dzone into its buffer zone and free dzone.
 */
static int dmz_reclaim_seq_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
{ … }

/*
 * Move valid blocks of the random data zone dzone into a free sequential zone.
 * Once blocks are moved, remap the zone chunk to the sequential zone.
 */
static int dmz_reclaim_rnd_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
{ … }

/*
 * Reclaim an empty zone.
 */
static void dmz_reclaim_empty(struct dmz_reclaim *zrc, struct dm_zone *dzone)
{ … }

/*
 * Test if the target device is idle.
 */
static inline int dmz_target_idle(struct dmz_reclaim *zrc)
{ … }

/*
 * Find a candidate zone for reclaim and process it.
 */
static int dmz_do_reclaim(struct dmz_reclaim *zrc)
{ … }

static unsigned int dmz_reclaim_percentage(struct dmz_reclaim *zrc)
{ … }

/*
 * Test if reclaim is necessary.
 */
static bool dmz_should_reclaim(struct dmz_reclaim *zrc, unsigned int p_unmap)
{ … }

/*
 * Reclaim work function.
 */
static void dmz_reclaim_work(struct work_struct *work)
{ … }

/*
 * Initialize reclaim.
 */
int dmz_ctr_reclaim(struct dmz_metadata *zmd,
		    struct dmz_reclaim **reclaim, int idx)
{ … }

/*
 * Terminate reclaim.
 */
void dmz_dtr_reclaim(struct dmz_reclaim *zrc)
{ … }

/*
 * Suspend reclaim.
 */
void dmz_suspend_reclaim(struct dmz_reclaim *zrc)
{ … }

/*
 * Resume reclaim.
 */
void dmz_resume_reclaim(struct dmz_reclaim *zrc)
{ … }

/*
 * BIO accounting.
 */
void dmz_reclaim_bio_acc(struct dmz_reclaim *zrc)
{ … }

/*
 * Start reclaim if necessary.
 */
void dmz_schedule_reclaim(struct dmz_reclaim *zrc)
{ … }