remove the lightnvm subsystem

Lightnvm supports the OCSSD 1.x and 2.0 specs which were early attempts
to produce Open Channel SSDs and never made it into the NVMe spec
proper.  They have since been superceeded by NVMe enhancements such
as ZNS support.  Remove the support per the deprecation schedule.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210812132308.38486-1-hch@lst.de
Reviewed-by: Matias Bjørling <mb@lightnvm.io>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 0 insertions, 726 deletions

diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
deleted file mode 100644
index b31658be35a7..000000000000
--- a/drivers/lightnvm/pblk-gc.c
+++ /dev/null
@@ -1,726 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2016 CNEX Labs
- * Initial release: Javier Gonzalez <javier@cnexlabs.com>
- *                  Matias Bjorling <matias@cnexlabs.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * pblk-gc.c - pblk's garbage collector
- */
-
-#include "pblk.h"
-#include "pblk-trace.h"
-#include <linux/delay.h>
-
-
-static void pblk_gc_free_gc_rq(struct pblk_gc_rq *gc_rq)
-{
-	vfree(gc_rq->data);
-	kfree(gc_rq);
-}
-
-static int pblk_gc_write(struct pblk *pblk)
-{
-	struct pblk_gc *gc = &pblk->gc;
-	struct pblk_gc_rq *gc_rq, *tgc_rq;
-	LIST_HEAD(w_list);
-
-	spin_lock(&gc->w_lock);
-	if (list_empty(&gc->w_list)) {
-		spin_unlock(&gc->w_lock);
-		return 1;
-	}
-
-	list_cut_position(&w_list, &gc->w_list, gc->w_list.prev);
-	gc->w_entries = 0;
-	spin_unlock(&gc->w_lock);
-
-	list_for_each_entry_safe(gc_rq, tgc_rq, &w_list, list) {
-		pblk_write_gc_to_cache(pblk, gc_rq);
-		list_del(&gc_rq->list);
-		kref_put(&gc_rq->line->ref, pblk_line_put);
-		pblk_gc_free_gc_rq(gc_rq);
-	}
-
-	return 0;
-}
-
-static void pblk_gc_writer_kick(struct pblk_gc *gc)
-{
-	wake_up_process(gc->gc_writer_ts);
-}
-
-void pblk_put_line_back(struct pblk *pblk, struct pblk_line *line)
-{
-	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
-	struct list_head *move_list;
-
-	spin_lock(&l_mg->gc_lock);
-	spin_lock(&line->lock);
-	WARN_ON(line->state != PBLK_LINESTATE_GC);
-	line->state = PBLK_LINESTATE_CLOSED;
-	trace_pblk_line_state(pblk_disk_name(pblk), line->id,
-					line->state);
-
-	/* We need to reset gc_group in order to ensure that
-	 * pblk_line_gc_list will return proper move_list
-	 * since right now current line is not on any of the
-	 * gc lists.
-	 */
-	line->gc_group = PBLK_LINEGC_NONE;
-	move_list = pblk_line_gc_list(pblk, line);
-	spin_unlock(&line->lock);
-	list_add_tail(&line->list, move_list);
-	spin_unlock(&l_mg->gc_lock);
-}
-
-static void pblk_gc_line_ws(struct work_struct *work)
-{
-	struct pblk_line_ws *gc_rq_ws = container_of(work,
-						struct pblk_line_ws, ws);
-	struct pblk *pblk = gc_rq_ws->pblk;
-	struct pblk_gc *gc = &pblk->gc;
-	struct pblk_line *line = gc_rq_ws->line;
-	struct pblk_gc_rq *gc_rq = gc_rq_ws->priv;
-	int ret;
-
-	up(&gc->gc_sem);
-
-	/* Read from GC victim block */
-	ret = pblk_submit_read_gc(pblk, gc_rq);
-	if (ret) {
-		line->w_err_gc->has_gc_err = 1;
-		goto out;
-	}
-
-	if (!gc_rq->secs_to_gc)
-		goto out;
-
-retry:
-	spin_lock(&gc->w_lock);
-	if (gc->w_entries >= PBLK_GC_RQ_QD) {
-		spin_unlock(&gc->w_lock);
-		pblk_gc_writer_kick(&pblk->gc);
-		usleep_range(128, 256);
-		goto retry;
-	}
-	gc->w_entries++;
-	list_add_tail(&gc_rq->list, &gc->w_list);
-	spin_unlock(&gc->w_lock);
-
-	pblk_gc_writer_kick(&pblk->gc);
-
-	kfree(gc_rq_ws);
-	return;
-
-out:
-	pblk_gc_free_gc_rq(gc_rq);
-	kref_put(&line->ref, pblk_line_put);
-	kfree(gc_rq_ws);
-}
-
-static __le64 *get_lba_list_from_emeta(struct pblk *pblk,
-				       struct pblk_line *line)
-{
-	struct line_emeta *emeta_buf;
-	struct pblk_line_meta *lm = &pblk->lm;
-	unsigned int lba_list_size = lm->emeta_len[2];
-	__le64 *lba_list;
-	int ret;
-
-	emeta_buf = kvmalloc(lm->emeta_len[0], GFP_KERNEL);
-	if (!emeta_buf)
-		return NULL;
-
-	ret = pblk_line_emeta_read(pblk, line, emeta_buf);
-	if (ret) {
-		pblk_err(pblk, "line %d read emeta failed (%d)\n",
-				line->id, ret);
-		kvfree(emeta_buf);
-		return NULL;
-	}
-
-	/* If this read fails, it means that emeta is corrupted.
-	 * For now, leave the line untouched.
-	 * TODO: Implement a recovery routine that scans and moves
-	 * all sectors on the line.
-	 */
-
-	ret = pblk_recov_check_emeta(pblk, emeta_buf);
-	if (ret) {
-		pblk_err(pblk, "inconsistent emeta (line %d)\n",
-				line->id);
-		kvfree(emeta_buf);
-		return NULL;
-	}
-
-	lba_list = kvmalloc(lba_list_size, GFP_KERNEL);
-
-	if (lba_list)
-		memcpy(lba_list, emeta_to_lbas(pblk, emeta_buf), lba_list_size);
-
-	kvfree(emeta_buf);
-
-	return lba_list;
-}
-
-static void pblk_gc_line_prepare_ws(struct work_struct *work)
-{
-	struct pblk_line_ws *line_ws = container_of(work, struct pblk_line_ws,
-									ws);
-	struct pblk *pblk = line_ws->pblk;
-	struct pblk_line *line = line_ws->line;
-	struct pblk_line_meta *lm = &pblk->lm;
-	struct nvm_tgt_dev *dev = pblk->dev;
-	struct nvm_geo *geo = &dev->geo;
-	struct pblk_gc *gc = &pblk->gc;
-	struct pblk_line_ws *gc_rq_ws;
-	struct pblk_gc_rq *gc_rq;
-	__le64 *lba_list;
-	unsigned long *invalid_bitmap;
-	int sec_left, nr_secs, bit;
-
-	invalid_bitmap = kmalloc(lm->sec_bitmap_len, GFP_KERNEL);
-	if (!invalid_bitmap)
-		goto fail_free_ws;
-
-	if (line->w_err_gc->has_write_err) {
-		lba_list = line->w_err_gc->lba_list;
-		line->w_err_gc->lba_list = NULL;
-	} else {
-		lba_list = get_lba_list_from_emeta(pblk, line);
-		if (!lba_list) {
-			pblk_err(pblk, "could not interpret emeta (line %d)\n",
-					line->id);
-			goto fail_free_invalid_bitmap;
-		}
-	}
-
-	spin_lock(&line->lock);
-	bitmap_copy(invalid_bitmap, line->invalid_bitmap, lm->sec_per_line);
-	sec_left = pblk_line_vsc(line);
-	spin_unlock(&line->lock);
-
-	if (sec_left < 0) {
-		pblk_err(pblk, "corrupted GC line (%d)\n", line->id);
-		goto fail_free_lba_list;
-	}
-
-	bit = -1;
-next_rq:
-	gc_rq = kmalloc(sizeof(struct pblk_gc_rq), GFP_KERNEL);
-	if (!gc_rq)
-		goto fail_free_lba_list;
-
-	nr_secs = 0;
-	do {
-		bit = find_next_zero_bit(invalid_bitmap, lm->sec_per_line,
-								bit + 1);
-		if (bit > line->emeta_ssec)
-			break;
-
-		gc_rq->paddr_list[nr_secs] = bit;
-		gc_rq->lba_list[nr_secs++] = le64_to_cpu(lba_list[bit]);
-	} while (nr_secs < pblk->max_write_pgs);
-
-	if (unlikely(!nr_secs)) {
-		kfree(gc_rq);
-		goto out;
-	}
-
-	gc_rq->nr_secs = nr_secs;
-	gc_rq->line = line;
-
-	gc_rq->data = vmalloc(array_size(gc_rq->nr_secs, geo->csecs));
-	if (!gc_rq->data)
-		goto fail_free_gc_rq;
-
-	gc_rq_ws = kmalloc(sizeof(struct pblk_line_ws), GFP_KERNEL);
-	if (!gc_rq_ws)
-		goto fail_free_gc_data;
-
-	gc_rq_ws->pblk = pblk;
-	gc_rq_ws->line = line;
-	gc_rq_ws->priv = gc_rq;
-
-	/* The write GC path can be much slower than the read GC one due to
-	 * the budget imposed by the rate-limiter. Balance in case that we get
-	 * back pressure from the write GC path.
-	 */
-	while (down_timeout(&gc->gc_sem, msecs_to_jiffies(30000)))
-		io_schedule();
-
-	kref_get(&line->ref);
-
-	INIT_WORK(&gc_rq_ws->ws, pblk_gc_line_ws);
-	queue_work(gc->gc_line_reader_wq, &gc_rq_ws->ws);
-
-	sec_left -= nr_secs;
-	if (sec_left > 0)
-		goto next_rq;
-
-out:
-	kvfree(lba_list);
-	kfree(line_ws);
-	kfree(invalid_bitmap);
-
-	kref_put(&line->ref, pblk_line_put);
-	atomic_dec(&gc->read_inflight_gc);
-
-	return;
-
-fail_free_gc_data:
-	vfree(gc_rq->data);
-fail_free_gc_rq:
-	kfree(gc_rq);
-fail_free_lba_list:
-	kvfree(lba_list);
-fail_free_invalid_bitmap:
-	kfree(invalid_bitmap);
-fail_free_ws:
-	kfree(line_ws);
-
-	/* Line goes back to closed state, so we cannot release additional
-	 * reference for line, since we do that only when we want to do
-	 * gc to free line state transition.
-	 */
-	pblk_put_line_back(pblk, line);
-	atomic_dec(&gc->read_inflight_gc);
-
-	pblk_err(pblk, "failed to GC line %d\n", line->id);
-}
-
-static int pblk_gc_line(struct pblk *pblk, struct pblk_line *line)
-{
-	struct pblk_gc *gc = &pblk->gc;
-	struct pblk_line_ws *line_ws;
-
-	pblk_debug(pblk, "line '%d' being reclaimed for GC\n", line->id);
-
-	line_ws = kmalloc(sizeof(struct pblk_line_ws), GFP_KERNEL);
-	if (!line_ws)
-		return -ENOMEM;
-
-	line_ws->pblk = pblk;
-	line_ws->line = line;
-
-	atomic_inc(&gc->pipeline_gc);
-	INIT_WORK(&line_ws->ws, pblk_gc_line_prepare_ws);
-	queue_work(gc->gc_reader_wq, &line_ws->ws);
-
-	return 0;
-}
-
-static void pblk_gc_reader_kick(struct pblk_gc *gc)
-{
-	wake_up_process(gc->gc_reader_ts);
-}
-
-static void pblk_gc_kick(struct pblk *pblk)
-{
-	struct pblk_gc *gc = &pblk->gc;
-
-	pblk_gc_writer_kick(gc);
-	pblk_gc_reader_kick(gc);
-
-	/* If we're shutting down GC, let's not start it up again */
-	if (gc->gc_enabled) {
-		wake_up_process(gc->gc_ts);
-		mod_timer(&gc->gc_timer,
-			  jiffies + msecs_to_jiffies(GC_TIME_MSECS));
-	}
-}
-
-static int pblk_gc_read(struct pblk *pblk)
-{
-	struct pblk_gc *gc = &pblk->gc;
-	struct pblk_line *line;
-
-	spin_lock(&gc->r_lock);
-	if (list_empty(&gc->r_list)) {
-		spin_unlock(&gc->r_lock);
-		return 1;
-	}
-
-	line = list_first_entry(&gc->r_list, struct pblk_line, list);
-	list_del(&line->list);
-	spin_unlock(&gc->r_lock);
-
-	pblk_gc_kick(pblk);
-
-	if (pblk_gc_line(pblk, line)) {
-		pblk_err(pblk, "failed to GC line %d\n", line->id);
-		/* rollback */
-		spin_lock(&gc->r_lock);
-		list_add_tail(&line->list, &gc->r_list);
-		spin_unlock(&gc->r_lock);
-	}
-
-	return 0;
-}
-
-static struct pblk_line *pblk_gc_get_victim_line(struct pblk *pblk,
-						 struct list_head *group_list)
-{
-	struct pblk_line *line, *victim;
-	unsigned int line_vsc = ~0x0L, victim_vsc = ~0x0L;
-
-	victim = list_first_entry(group_list, struct pblk_line, list);
-
-	list_for_each_entry(line, group_list, list) {
-		if (!atomic_read(&line->sec_to_update))
-			line_vsc = le32_to_cpu(*line->vsc);
-		if (line_vsc < victim_vsc) {
-			victim = line;
-			victim_vsc = le32_to_cpu(*victim->vsc);
-		}
-	}
-
-	if (victim_vsc == ~0x0)
-		return NULL;
-
-	return victim;
-}
-
-static bool pblk_gc_should_run(struct pblk_gc *gc, struct pblk_rl *rl)
-{
-	unsigned int nr_blocks_free, nr_blocks_need;
-	unsigned int werr_lines = atomic_read(&rl->werr_lines);
-
-	nr_blocks_need = pblk_rl_high_thrs(rl);
-	nr_blocks_free = pblk_rl_nr_free_blks(rl);
-
-	/* This is not critical, no need to take lock here */
-	return ((werr_lines > 0) ||
-		((gc->gc_active) && (nr_blocks_need > nr_blocks_free)));
-}
-
-void pblk_gc_free_full_lines(struct pblk *pblk)
-{
-	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
-	struct pblk_gc *gc = &pblk->gc;
-	struct pblk_line *line;
-
-	do {
-		spin_lock(&l_mg->gc_lock);
-		if (list_empty(&l_mg->gc_full_list)) {
-			spin_unlock(&l_mg->gc_lock);
-			return;
-		}
-
-		line = list_first_entry(&l_mg->gc_full_list,
-							struct pblk_line, list);
-
-		spin_lock(&line->lock);
-		WARN_ON(line->state != PBLK_LINESTATE_CLOSED);
-		line->state = PBLK_LINESTATE_GC;
-		trace_pblk_line_state(pblk_disk_name(pblk), line->id,
-					line->state);
-		spin_unlock(&line->lock);
-
-		list_del(&line->list);
-		spin_unlock(&l_mg->gc_lock);
-
-		atomic_inc(&gc->pipeline_gc);
-		kref_put(&line->ref, pblk_line_put);
-	} while (1);
-}
-
-/*
- * Lines with no valid sectors will be returned to the free list immediately. If
- * GC is activated - either because the free block count is under the determined
- * threshold, or because it is being forced from user space - only lines with a
- * high count of invalid sectors will be recycled.
- */
-static void pblk_gc_run(struct pblk *pblk)
-{
-	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
-	struct pblk_gc *gc = &pblk->gc;
-	struct pblk_line *line;
-	struct list_head *group_list;
-	bool run_gc;
-	int read_inflight_gc, gc_group = 0, prev_group = 0;
-
-	pblk_gc_free_full_lines(pblk);
-
-	run_gc = pblk_gc_should_run(&pblk->gc, &pblk->rl);
-	if (!run_gc || (atomic_read(&gc->read_inflight_gc) >= PBLK_GC_L_QD))
-		return;
-
-next_gc_group:
-	group_list = l_mg->gc_lists[gc_group++];
-
-	do {
-		spin_lock(&l_mg->gc_lock);
-
-		line = pblk_gc_get_victim_line(pblk, group_list);
-		if (!line) {
-			spin_unlock(&l_mg->gc_lock);
-			break;
-		}
-
-		spin_lock(&line->lock);
-		WARN_ON(line->state != PBLK_LINESTATE_CLOSED);
-		line->state = PBLK_LINESTATE_GC;
-		trace_pblk_line_state(pblk_disk_name(pblk), line->id,
-					line->state);
-		spin_unlock(&line->lock);
-
-		list_del(&line->list);
-		spin_unlock(&l_mg->gc_lock);
-
-		spin_lock(&gc->r_lock);
-		list_add_tail(&line->list, &gc->r_list);
-		spin_unlock(&gc->r_lock);
-
-		read_inflight_gc = atomic_inc_return(&gc->read_inflight_gc);
-		pblk_gc_reader_kick(gc);
-
-		prev_group = 1;
-
-		/* No need to queue up more GC lines than we can handle */
-		run_gc = pblk_gc_should_run(&pblk->gc, &pblk->rl);
-		if (!run_gc || read_inflight_gc >= PBLK_GC_L_QD)
-			break;
-	} while (1);
-
-	if (!prev_group && pblk->rl.rb_state > gc_group &&
-						gc_group < PBLK_GC_NR_LISTS)
-		goto next_gc_group;
-}
-
-static void pblk_gc_timer(struct timer_list *t)
-{
-	struct pblk *pblk = from_timer(pblk, t, gc.gc_timer);
-
-	pblk_gc_kick(pblk);
-}
-
-static int pblk_gc_ts(void *data)
-{
-	struct pblk *pblk = data;
-
-	while (!kthread_should_stop()) {
-		pblk_gc_run(pblk);
-		set_current_state(TASK_INTERRUPTIBLE);
-		io_schedule();
-	}
-
-	return 0;
-}
-
-static int pblk_gc_writer_ts(void *data)
-{
-	struct pblk *pblk = data;
-
-	while (!kthread_should_stop()) {
-		if (!pblk_gc_write(pblk))
-			continue;
-		set_current_state(TASK_INTERRUPTIBLE);
-		io_schedule();
-	}
-
-	return 0;
-}
-
-static int pblk_gc_reader_ts(void *data)
-{
-	struct pblk *pblk = data;
-	struct pblk_gc *gc = &pblk->gc;
-
-	while (!kthread_should_stop()) {
-		if (!pblk_gc_read(pblk))
-			continue;
-		set_current_state(TASK_INTERRUPTIBLE);
-		io_schedule();
-	}
-
-#ifdef CONFIG_NVM_PBLK_DEBUG
-	pblk_info(pblk, "flushing gc pipeline, %d lines left\n",
-		atomic_read(&gc->pipeline_gc));
-#endif
-
-	do {
-		if (!atomic_read(&gc->pipeline_gc))
-			break;
-
-		schedule();
-	} while (1);
-
-	return 0;
-}
-
-static void pblk_gc_start(struct pblk *pblk)
-{
-	pblk->gc.gc_active = 1;
-	pblk_debug(pblk, "gc start\n");
-}
-
-void pblk_gc_should_start(struct pblk *pblk)
-{
-	struct pblk_gc *gc = &pblk->gc;
-
-	if (gc->gc_enabled && !gc->gc_active) {
-		pblk_gc_start(pblk);
-		pblk_gc_kick(pblk);
-	}
-}
-
-void pblk_gc_should_stop(struct pblk *pblk)
-{
-	struct pblk_gc *gc = &pblk->gc;
-
-	if (gc->gc_active && !gc->gc_forced)
-		gc->gc_active = 0;
-}
-
-void pblk_gc_should_kick(struct pblk *pblk)
-{
-	pblk_rl_update_rates(&pblk->rl);
-}
-
-void pblk_gc_sysfs_state_show(struct pblk *pblk, int *gc_enabled,
-			      int *gc_active)
-{
-	struct pblk_gc *gc = &pblk->gc;
-
-	spin_lock(&gc->lock);
-	*gc_enabled = gc->gc_enabled;
-	*gc_active = gc->gc_active;
-	spin_unlock(&gc->lock);
-}
-
-int pblk_gc_sysfs_force(struct pblk *pblk, int force)
-{
-	struct pblk_gc *gc = &pblk->gc;
-
-	if (force < 0 || force > 1)
-		return -EINVAL;
-
-	spin_lock(&gc->lock);
-	gc->gc_forced = force;
-
-	if (force)
-		gc->gc_enabled = 1;
-	else
-		gc->gc_enabled = 0;
-	spin_unlock(&gc->lock);
-
-	pblk_gc_should_start(pblk);
-
-	return 0;
-}
-
-int pblk_gc_init(struct pblk *pblk)
-{
-	struct pblk_gc *gc = &pblk->gc;
-	int ret;
-
-	gc->gc_ts = kthread_create(pblk_gc_ts, pblk, "pblk-gc-ts");
-	if (IS_ERR(gc->gc_ts)) {
-		pblk_err(pblk, "could not allocate GC main kthread\n");
-		return PTR_ERR(gc->gc_ts);
-	}
-
-	gc->gc_writer_ts = kthread_create(pblk_gc_writer_ts, pblk,
-							"pblk-gc-writer-ts");
-	if (IS_ERR(gc->gc_writer_ts)) {
-		pblk_err(pblk, "could not allocate GC writer kthread\n");
-		ret = PTR_ERR(gc->gc_writer_ts);
-		goto fail_free_main_kthread;
-	}
-
-	gc->gc_reader_ts = kthread_create(pblk_gc_reader_ts, pblk,
-							"pblk-gc-reader-ts");
-	if (IS_ERR(gc->gc_reader_ts)) {
-		pblk_err(pblk, "could not allocate GC reader kthread\n");
-		ret = PTR_ERR(gc->gc_reader_ts);
-		goto fail_free_writer_kthread;
-	}
-
-	timer_setup(&gc->gc_timer, pblk_gc_timer, 0);
-	mod_timer(&gc->gc_timer, jiffies + msecs_to_jiffies(GC_TIME_MSECS));
-
-	gc->gc_active = 0;
-	gc->gc_forced = 0;
-	gc->gc_enabled = 1;
-	gc->w_entries = 0;
-	atomic_set(&gc->read_inflight_gc, 0);
-	atomic_set(&gc->pipeline_gc, 0);
-
-	/* Workqueue that reads valid sectors from a line and submit them to the
-	 * GC writer to be recycled.
-	 */
-	gc->gc_line_reader_wq = alloc_workqueue("pblk-gc-line-reader-wq",
-			WQ_MEM_RECLAIM | WQ_UNBOUND, PBLK_GC_MAX_READERS);
-	if (!gc->gc_line_reader_wq) {
-		pblk_err(pblk, "could not allocate GC line reader workqueue\n");
-		ret = -ENOMEM;
-		goto fail_free_reader_kthread;
-	}
-
-	/* Workqueue that prepare lines for GC */
-	gc->gc_reader_wq = alloc_workqueue("pblk-gc-line_wq",
-					WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
-	if (!gc->gc_reader_wq) {
-		pblk_err(pblk, "could not allocate GC reader workqueue\n");
-		ret = -ENOMEM;
-		goto fail_free_reader_line_wq;
-	}
-
-	spin_lock_init(&gc->lock);
-	spin_lock_init(&gc->w_lock);
-	spin_lock_init(&gc->r_lock);
-
-	sema_init(&gc->gc_sem, PBLK_GC_RQ_QD);
-
-	INIT_LIST_HEAD(&gc->w_list);
-	INIT_LIST_HEAD(&gc->r_list);
-
-	return 0;
-
-fail_free_reader_line_wq:
-	destroy_workqueue(gc->gc_line_reader_wq);
-fail_free_reader_kthread:
-	kthread_stop(gc->gc_reader_ts);
-fail_free_writer_kthread:
-	kthread_stop(gc->gc_writer_ts);
-fail_free_main_kthread:
-	kthread_stop(gc->gc_ts);
-
-	return ret;
-}
-
-void pblk_gc_exit(struct pblk *pblk, bool graceful)
-{
-	struct pblk_gc *gc = &pblk->gc;
-
-	gc->gc_enabled = 0;
-	del_timer_sync(&gc->gc_timer);
-	gc->gc_active = 0;
-
-	if (gc->gc_ts)
-		kthread_stop(gc->gc_ts);
-
-	if (gc->gc_reader_ts)
-		kthread_stop(gc->gc_reader_ts);
-
-	if (graceful) {
-		flush_workqueue(gc->gc_reader_wq);
-		flush_workqueue(gc->gc_line_reader_wq);
-	}
-
-	destroy_workqueue(gc->gc_reader_wq);
-	destroy_workqueue(gc->gc_line_reader_wq);
-
-	if (gc->gc_writer_ts)
-		kthread_stop(gc->gc_writer_ts);
-}