netfilter: conntrack: rename nf_ct_iterate_cleanup

[mirror_ubuntu-artful-kernel.git] / drivers / lightnvm / pblk-gc.c

/*
 * 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 <linux/delay.h>

static void pblk_gc_free_gc_rq(struct pblk_gc_rq *gc_rq)
{
        kfree(gc_rq->data);
        kfree(gc_rq->lba_list);
        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_for_each_entry_safe(gc_rq, tgc_rq, &gc->w_list, list) {
                list_move_tail(&gc_rq->list, &w_list);
                gc->w_entries--;
        }
        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->data, gc_rq->lba_list,
                                gc_rq->nr_secs, gc_rq->secs_to_gc,
                                gc_rq->line, PBLK_IOTYPE_GC);

                kref_put(&gc_rq->line->ref, pblk_line_put);

                list_del(&gc_rq->list);
                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);
}

/*
 * Responsible for managing all memory related to a gc request. Also in case of
 * failure
 */
static int pblk_gc_move_valid_secs(struct pblk *pblk, struct pblk_line *line,
                                   u64 *lba_list, unsigned int nr_secs)
{
        struct nvm_tgt_dev *dev = pblk->dev;
        struct nvm_geo *geo = &dev->geo;
        struct pblk_gc *gc = &pblk->gc;
        struct pblk_gc_rq *gc_rq;
        void *data;
        unsigned int secs_to_gc;
        int ret = NVM_IO_OK;

        data = kmalloc(nr_secs * geo->sec_size, GFP_KERNEL);
        if (!data) {
                ret = NVM_IO_ERR;
                goto free_lba_list;
        }

        /* Read from GC victim block */
        if (pblk_submit_read_gc(pblk, lba_list, data, nr_secs,
                                                        &secs_to_gc, line)) {
                ret = NVM_IO_ERR;
                goto free_data;
        }

        if (!secs_to_gc)
                goto free_data;

        gc_rq = kmalloc(sizeof(struct pblk_gc_rq), GFP_KERNEL);
        if (!gc_rq) {
                ret = NVM_IO_ERR;
                goto free_data;
        }

        gc_rq->line = line;
        gc_rq->data = data;
        gc_rq->lba_list = lba_list;
        gc_rq->nr_secs = nr_secs;
        gc_rq->secs_to_gc = secs_to_gc;

        kref_get(&line->ref);

retry:
        spin_lock(&gc->w_lock);
        if (gc->w_entries > 256) {
                spin_unlock(&gc->w_lock);
                usleep_range(256, 1024);
                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);

        return NVM_IO_OK;

free_data:
        kfree(data);
free_lba_list:
        kfree(lba_list);

        return ret;
}

static 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(&line->lock);
        WARN_ON(line->state != PBLK_LINESTATE_GC);
        line->state = PBLK_LINESTATE_CLOSED;
        move_list = pblk_line_gc_list(pblk, line);
        spin_unlock(&line->lock);

        if (move_list) {
                spin_lock(&l_mg->gc_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 *line_ws = container_of(work, struct pblk_line_ws,
                                                                        ws);
        struct pblk *pblk = line_ws->pblk;
        struct pblk_line_mgmt *l_mg = &pblk->l_mg;
        struct pblk_line *line = line_ws->line;
        struct pblk_line_meta *lm = &pblk->lm;
        __le64 *lba_list = line_ws->priv;
        u64 *gc_list;
        int sec_left;
        int nr_ppas, bit;
        int put_line = 1;

        pr_debug("pblk: line '%d' being reclaimed for GC\n", line->id);

        spin_lock(&line->lock);
        sec_left = line->vsc;
        if (!sec_left) {
                /* Lines are erased before being used (l_mg->data_/log_next) */
                spin_unlock(&line->lock);
                goto out;
        }
        spin_unlock(&line->lock);

        if (sec_left < 0) {
                pr_err("pblk: corrupted GC line (%d)\n", line->id);
                put_line = 0;
                pblk_put_line_back(pblk, line);
                goto out;
        }

        bit = -1;
next_rq:
        gc_list = kmalloc_array(pblk->max_write_pgs, sizeof(u64), GFP_KERNEL);
        if (!gc_list) {
                put_line = 0;
                pblk_put_line_back(pblk, line);
                goto out;
        }

        nr_ppas = 0;
        do {
                bit = find_next_zero_bit(line->invalid_bitmap, lm->sec_per_line,
                                                                bit + 1);
                if (bit > line->emeta_ssec)
                        break;

                gc_list[nr_ppas++] = le64_to_cpu(lba_list[bit]);
        } while (nr_ppas < pblk->max_write_pgs);

        if (unlikely(!nr_ppas)) {
                kfree(gc_list);
                goto out;
        }

        if (pblk_gc_move_valid_secs(pblk, line, gc_list, nr_ppas)) {
                pr_err("pblk: could not GC all sectors: line:%d (%d/%d/%d)\n",
                                                line->id, line->vsc,
                                                nr_ppas, nr_ppas);
                put_line = 0;
                pblk_put_line_back(pblk, line);
                goto out;
        }

        sec_left -= nr_ppas;
        if (sec_left > 0)
                goto next_rq;

out:
        pblk_mfree(line->emeta, l_mg->emeta_alloc_type);
        mempool_free(line_ws, pblk->line_ws_pool);
        atomic_dec(&pblk->gc.inflight_gc);
        if (put_line)
                kref_put(&line->ref, pblk_line_put);
}

static int pblk_gc_line(struct pblk *pblk, struct pblk_line *line)
{
        struct pblk_line_mgmt *l_mg = &pblk->l_mg;
        struct pblk_line_meta *lm = &pblk->lm;
        struct pblk_line_ws *line_ws;
        __le64 *lba_list;
        int ret;

        line_ws = mempool_alloc(pblk->line_ws_pool, GFP_KERNEL);
        line->emeta = pblk_malloc(lm->emeta_len, l_mg->emeta_alloc_type,
                                                                GFP_KERNEL);
        if (!line->emeta) {
                pr_err("pblk: cannot use GC emeta\n");
                goto fail_free_ws;
        }

        ret = pblk_line_read_emeta(pblk, line);
        if (ret) {
                pr_err("pblk: line %d read emeta failed (%d)\n", line->id, ret);
                goto fail_free_emeta;
        }

        /* 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.
         */
        lba_list = pblk_recov_get_lba_list(pblk, line->emeta);
        if (!lba_list) {
                pr_err("pblk: could not interpret emeta (line %d)\n", line->id);
                goto fail_free_emeta;
        }

        line_ws->pblk = pblk;
        line_ws->line = line;
        line_ws->priv = lba_list;

        INIT_WORK(&line_ws->ws, pblk_gc_line_ws);
        queue_work(pblk->gc.gc_reader_wq, &line_ws->ws);

        return 0;

fail_free_emeta:
        pblk_mfree(line->emeta, l_mg->emeta_alloc_type);
fail_free_ws:
        mempool_free(line_ws, pblk->line_ws_pool);
        pblk_put_line_back(pblk, line);

        return 1;
}

static void pblk_gc_lines(struct pblk *pblk, struct list_head *gc_list)
{
        struct pblk_line *line, *tline;

        list_for_each_entry_safe(line, tline, gc_list, list) {
                if (pblk_gc_line(pblk, line))
                        pr_err("pblk: failed to GC line %d\n", line->id);
                list_del(&line->list);
        }
}

/*
 * 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, *tline;
        unsigned int nr_blocks_free, nr_blocks_need;
        struct list_head *group_list;
        int run_gc, gc_group = 0;
        int prev_gc = 0;
        int inflight_gc = atomic_read(&gc->inflight_gc);
        LIST_HEAD(gc_list);

        spin_lock(&l_mg->gc_lock);
        list_for_each_entry_safe(line, tline, &l_mg->gc_full_list, list) {
                spin_lock(&line->lock);
                WARN_ON(line->state != PBLK_LINESTATE_CLOSED);
                line->state = PBLK_LINESTATE_GC;
                spin_unlock(&line->lock);

                list_del(&line->list);
                kref_put(&line->ref, pblk_line_put);
        }
        spin_unlock(&l_mg->gc_lock);

        nr_blocks_need = pblk_rl_gc_thrs(&pblk->rl);
        nr_blocks_free = pblk_rl_nr_free_blks(&pblk->rl);
        run_gc = (nr_blocks_need > nr_blocks_free || gc->gc_forced);

next_gc_group:
        group_list = l_mg->gc_lists[gc_group++];
        spin_lock(&l_mg->gc_lock);
        while (run_gc && !list_empty(group_list)) {
                /* No need to queue up more GC lines than we can handle */
                if (!run_gc || inflight_gc > gc->gc_jobs_active) {
                        spin_unlock(&l_mg->gc_lock);
                        pblk_gc_lines(pblk, &gc_list);
                        return;
                }

                line = list_first_entry(group_list, struct pblk_line, list);
                nr_blocks_free += atomic_read(&line->blk_in_line);

                spin_lock(&line->lock);
                WARN_ON(line->state != PBLK_LINESTATE_CLOSED);
                line->state = PBLK_LINESTATE_GC;
                list_move_tail(&line->list, &gc_list);
                atomic_inc(&gc->inflight_gc);
                inflight_gc++;
                spin_unlock(&line->lock);

                prev_gc = 1;
                run_gc = (nr_blocks_need > nr_blocks_free || gc->gc_forced);
        }
        spin_unlock(&l_mg->gc_lock);

        pblk_gc_lines(pblk, &gc_list);

        if (!prev_gc && pblk->rl.rb_state > gc_group &&
                                                gc_group < PBLK_NR_GC_LISTS)
                goto next_gc_group;
}


static void pblk_gc_kick(struct pblk *pblk)
{
        struct pblk_gc *gc = &pblk->gc;

        wake_up_process(gc->gc_ts);
        pblk_gc_writer_kick(gc);
        mod_timer(&gc->gc_timer, jiffies + msecs_to_jiffies(GC_TIME_MSECS));
}

static void pblk_gc_timer(unsigned long data)
{
        struct pblk *pblk = (struct pblk *)data;

        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 void pblk_gc_start(struct pblk *pblk)
{
        pblk->gc.gc_active = 1;

        pr_debug("pblk: gc start\n");
}

int pblk_gc_status(struct pblk *pblk)
{
        struct pblk_gc *gc = &pblk->gc;
        int ret;

        spin_lock(&gc->lock);
        ret = gc->gc_active;
        spin_unlock(&gc->lock);

        return ret;
}

static void __pblk_gc_should_start(struct pblk *pblk)
{
        struct pblk_gc *gc = &pblk->gc;

        lockdep_assert_held(&gc->lock);

        if (gc->gc_enabled && !gc->gc_active)
                pblk_gc_start(pblk);
}

void pblk_gc_should_start(struct pblk *pblk)
{
        struct pblk_gc *gc = &pblk->gc;

        spin_lock(&gc->lock);
        __pblk_gc_should_start(pblk);
        spin_unlock(&gc->lock);
}

/*
 * If flush_wq == 1 then no lock should be held by the caller since
 * flush_workqueue can sleep
 */
static void pblk_gc_stop(struct pblk *pblk, int flush_wq)
{
        spin_lock(&pblk->gc.lock);
        pblk->gc.gc_active = 0;
        spin_unlock(&pblk->gc.lock);

        pr_debug("pblk: gc stop\n");
}

void pblk_gc_should_stop(struct pblk *pblk)
{
        struct pblk_gc *gc = &pblk->gc;

        if (gc->gc_active && !gc->gc_forced)
                pblk_gc_stop(pblk, 0);
}

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);
}

void pblk_gc_sysfs_force(struct pblk *pblk, int force)
{
        struct pblk_gc *gc = &pblk->gc;
        int rsv = 0;

        spin_lock(&gc->lock);
        if (force) {
                gc->gc_enabled = 1;
                rsv = 64;
        }
        pblk_rl_set_gc_rsc(&pblk->rl, rsv);
        gc->gc_forced = force;
        __pblk_gc_should_start(pblk);
        spin_unlock(&gc->lock);
}

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)) {
                pr_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)) {
                pr_err("pblk: could not allocate GC writer kthread\n");
                ret = PTR_ERR(gc->gc_writer_ts);
                goto fail_free_main_kthread;
        }

        setup_timer(&gc->gc_timer, pblk_gc_timer, (unsigned long)pblk);
        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->gc_jobs_active = 8;
        gc->w_entries = 0;
        atomic_set(&gc->inflight_gc, 0);

        gc->gc_reader_wq = alloc_workqueue("pblk-gc-reader-wq",
                        WQ_MEM_RECLAIM | WQ_UNBOUND, gc->gc_jobs_active);
        if (!gc->gc_reader_wq) {
                pr_err("pblk: could not allocate GC reader workqueue\n");
                ret = -ENOMEM;
                goto fail_free_writer_kthread;
        }

        spin_lock_init(&gc->lock);
        spin_lock_init(&gc->w_lock);
        INIT_LIST_HEAD(&gc->w_list);

        return 0;

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)
{
        struct pblk_gc *gc = &pblk->gc;

        flush_workqueue(gc->gc_reader_wq);

        del_timer(&gc->gc_timer);
        pblk_gc_stop(pblk, 1);

        if (gc->gc_ts)
                kthread_stop(gc->gc_ts);

        if (pblk->gc.gc_reader_wq)
                destroy_workqueue(pblk->gc.gc_reader_wq);

        if (gc->gc_writer_ts)
                kthread_stop(gc->gc_writer_ts);
}