linux/drivers/lightnvm/pblk-write.c
Javier González ee8d5c1ad5 lightnvm: pblk: remove target using async. I/Os
When removing a pblk instance, pad the current line using asynchronous
I/O. This reduces the removal time from ~1 minute in the worst case to a
couple of seconds.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-30 11:08:18 -06:00

618 lines
16 KiB
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-write.c - pblk's write path from write buffer to media
*/
#include "pblk.h"
static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
struct pblk_c_ctx *c_ctx)
{
struct nvm_tgt_dev *dev = pblk->dev;
struct bio *original_bio;
unsigned long ret;
int i;
for (i = 0; i < c_ctx->nr_valid; i++) {
struct pblk_w_ctx *w_ctx;
w_ctx = pblk_rb_w_ctx(&pblk->rwb, c_ctx->sentry + i);
while ((original_bio = bio_list_pop(&w_ctx->bios)))
bio_endio(original_bio);
}
#ifdef CONFIG_NVM_DEBUG
atomic_long_add(c_ctx->nr_valid, &pblk->sync_writes);
#endif
ret = pblk_rb_sync_advance(&pblk->rwb, c_ctx->nr_valid);
if (rqd->meta_list)
nvm_dev_dma_free(dev->parent, rqd->meta_list,
rqd->dma_meta_list);
bio_put(rqd->bio);
pblk_free_rqd(pblk, rqd, WRITE);
return ret;
}
static unsigned long pblk_end_queued_w_bio(struct pblk *pblk,
struct nvm_rq *rqd,
struct pblk_c_ctx *c_ctx)
{
list_del(&c_ctx->list);
return pblk_end_w_bio(pblk, rqd, c_ctx);
}
static void pblk_complete_write(struct pblk *pblk, struct nvm_rq *rqd,
struct pblk_c_ctx *c_ctx)
{
struct pblk_c_ctx *c, *r;
unsigned long flags;
unsigned long pos;
#ifdef CONFIG_NVM_DEBUG
atomic_long_sub(c_ctx->nr_valid, &pblk->inflight_writes);
#endif
pblk_up_rq(pblk, rqd->ppa_list, rqd->nr_ppas, c_ctx->lun_bitmap);
pos = pblk_rb_sync_init(&pblk->rwb, &flags);
if (pos == c_ctx->sentry) {
pos = pblk_end_w_bio(pblk, rqd, c_ctx);
retry:
list_for_each_entry_safe(c, r, &pblk->compl_list, list) {
rqd = nvm_rq_from_c_ctx(c);
if (c->sentry == pos) {
pos = pblk_end_queued_w_bio(pblk, rqd, c);
goto retry;
}
}
} else {
WARN_ON(nvm_rq_from_c_ctx(c_ctx) != rqd);
list_add_tail(&c_ctx->list, &pblk->compl_list);
}
pblk_rb_sync_end(&pblk->rwb, &flags);
}
/* When a write fails, we are not sure whether the block has grown bad or a page
* range is more susceptible to write errors. If a high number of pages fail, we
* assume that the block is bad and we mark it accordingly. In all cases, we
* remap and resubmit the failed entries as fast as possible; if a flush is
* waiting on a completion, the whole stack would stall otherwise.
*/
static void pblk_end_w_fail(struct pblk *pblk, struct nvm_rq *rqd)
{
void *comp_bits = &rqd->ppa_status;
struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
struct pblk_rec_ctx *recovery;
struct ppa_addr *ppa_list = rqd->ppa_list;
int nr_ppas = rqd->nr_ppas;
unsigned int c_entries;
int bit, ret;
if (unlikely(nr_ppas == 1))
ppa_list = &rqd->ppa_addr;
recovery = mempool_alloc(pblk->rec_pool, GFP_ATOMIC);
if (!recovery) {
pr_err("pblk: could not allocate recovery context\n");
return;
}
INIT_LIST_HEAD(&recovery->failed);
bit = -1;
while ((bit = find_next_bit(comp_bits, nr_ppas, bit + 1)) < nr_ppas) {
struct pblk_rb_entry *entry;
struct ppa_addr ppa;
/* Logic error */
if (bit > c_ctx->nr_valid) {
WARN_ONCE(1, "pblk: corrupted write request\n");
mempool_free(recovery, pblk->rec_pool);
goto out;
}
ppa = ppa_list[bit];
entry = pblk_rb_sync_scan_entry(&pblk->rwb, &ppa);
if (!entry) {
pr_err("pblk: could not scan entry on write failure\n");
mempool_free(recovery, pblk->rec_pool);
goto out;
}
/* The list is filled first and emptied afterwards. No need for
* protecting it with a lock
*/
list_add_tail(&entry->index, &recovery->failed);
}
c_entries = find_first_bit(comp_bits, nr_ppas);
ret = pblk_recov_setup_rq(pblk, c_ctx, recovery, comp_bits, c_entries);
if (ret) {
pr_err("pblk: could not recover from write failure\n");
mempool_free(recovery, pblk->rec_pool);
goto out;
}
INIT_WORK(&recovery->ws_rec, pblk_submit_rec);
queue_work(pblk->close_wq, &recovery->ws_rec);
out:
pblk_complete_write(pblk, rqd, c_ctx);
}
static void pblk_end_io_write(struct nvm_rq *rqd)
{
struct pblk *pblk = rqd->private;
struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
if (rqd->error) {
pblk_log_write_err(pblk, rqd);
return pblk_end_w_fail(pblk, rqd);
}
#ifdef CONFIG_NVM_DEBUG
else
WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
#endif
pblk_complete_write(pblk, rqd, c_ctx);
atomic_dec(&pblk->inflight_io);
}
static void pblk_end_io_write_meta(struct nvm_rq *rqd)
{
struct pblk *pblk = rqd->private;
struct nvm_tgt_dev *dev = pblk->dev;
struct nvm_geo *geo = &dev->geo;
struct pblk_g_ctx *m_ctx = nvm_rq_to_pdu(rqd);
struct pblk_line *line = m_ctx->private;
struct pblk_emeta *emeta = line->emeta;
int pos = pblk_ppa_to_pos(geo, rqd->ppa_list[0]);
struct pblk_lun *rlun = &pblk->luns[pos];
int sync;
up(&rlun->wr_sem);
if (rqd->error) {
pblk_log_write_err(pblk, rqd);
pr_err("pblk: metadata I/O failed. Line %d\n", line->id);
}
#ifdef CONFIG_NVM_DEBUG
else
WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
#endif
sync = atomic_add_return(rqd->nr_ppas, &emeta->sync);
if (sync == emeta->nr_entries)
pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws,
pblk->close_wq);
bio_put(rqd->bio);
pblk_free_rqd(pblk, rqd, READ);
atomic_dec(&pblk->inflight_io);
}
static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
unsigned int nr_secs,
nvm_end_io_fn(*end_io))
{
struct nvm_tgt_dev *dev = pblk->dev;
/* Setup write request */
rqd->opcode = NVM_OP_PWRITE;
rqd->nr_ppas = nr_secs;
rqd->flags = pblk_set_progr_mode(pblk, WRITE);
rqd->private = pblk;
rqd->end_io = end_io;
rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
&rqd->dma_meta_list);
if (!rqd->meta_list)
return -ENOMEM;
if (unlikely(nr_secs == 1))
return 0;
rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
return 0;
}
static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
struct pblk_c_ctx *c_ctx, struct ppa_addr *erase_ppa)
{
struct pblk_line_meta *lm = &pblk->lm;
struct pblk_line *e_line = pblk_line_get_erase(pblk);
unsigned int valid = c_ctx->nr_valid;
unsigned int padded = c_ctx->nr_padded;
unsigned int nr_secs = valid + padded;
unsigned long *lun_bitmap;
int ret = 0;
lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
if (!lun_bitmap)
return -ENOMEM;
c_ctx->lun_bitmap = lun_bitmap;
ret = pblk_alloc_w_rq(pblk, rqd, nr_secs, pblk_end_io_write);
if (ret) {
kfree(lun_bitmap);
return ret;
}
if (likely(!e_line || !atomic_read(&e_line->left_eblks)))
pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
else
pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
valid, erase_ppa);
return 0;
}
int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
struct pblk_c_ctx *c_ctx)
{
struct pblk_line_meta *lm = &pblk->lm;
unsigned long *lun_bitmap;
int ret;
lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
if (!lun_bitmap)
return -ENOMEM;
c_ctx->lun_bitmap = lun_bitmap;
ret = pblk_alloc_w_rq(pblk, rqd, rqd->nr_ppas, pblk_end_io_write);
if (ret)
return ret;
pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, c_ctx->nr_valid, 0);
rqd->ppa_status = (u64)0;
rqd->flags = pblk_set_progr_mode(pblk, WRITE);
return ret;
}
static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
unsigned int secs_to_flush)
{
int secs_to_sync;
secs_to_sync = pblk_calc_secs(pblk, secs_avail, secs_to_flush);
#ifdef CONFIG_NVM_DEBUG
if ((!secs_to_sync && secs_to_flush)
|| (secs_to_sync < 0)
|| (secs_to_sync > secs_avail && !secs_to_flush)) {
pr_err("pblk: bad sector calculation (a:%d,s:%d,f:%d)\n",
secs_avail, secs_to_sync, secs_to_flush);
}
#endif
return secs_to_sync;
}
static inline int pblk_valid_meta_ppa(struct pblk *pblk,
struct pblk_line *meta_line,
struct ppa_addr *ppa_list, int nr_ppas)
{
struct nvm_tgt_dev *dev = pblk->dev;
struct nvm_geo *geo = &dev->geo;
struct pblk_line *data_line;
struct ppa_addr ppa, ppa_opt;
u64 paddr;
int i;
data_line = &pblk->lines[pblk_dev_ppa_to_line(ppa_list[0])];
paddr = pblk_lookup_page(pblk, meta_line);
ppa = addr_to_gen_ppa(pblk, paddr, 0);
if (test_bit(pblk_ppa_to_pos(geo, ppa), data_line->blk_bitmap))
return 1;
/* Schedule a metadata I/O that is half the distance from the data I/O
* with regards to the number of LUNs forming the pblk instance. This
* balances LUN conflicts across every I/O.
*
* When the LUN configuration changes (e.g., due to GC), this distance
* can align, which would result on a LUN deadlock. In this case, modify
* the distance to not be optimal, but allow metadata I/Os to succeed.
*/
ppa_opt = addr_to_gen_ppa(pblk, paddr + data_line->meta_distance, 0);
if (unlikely(ppa_opt.ppa == ppa.ppa)) {
data_line->meta_distance--;
return 0;
}
for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
if (ppa_list[i].g.ch == ppa_opt.g.ch &&
ppa_list[i].g.lun == ppa_opt.g.lun)
return 1;
if (test_bit(pblk_ppa_to_pos(geo, ppa_opt), data_line->blk_bitmap)) {
for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
if (ppa_list[i].g.ch == ppa.g.ch &&
ppa_list[i].g.lun == ppa.g.lun)
return 0;
return 1;
}
return 0;
}
int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
{
struct nvm_tgt_dev *dev = pblk->dev;
struct nvm_geo *geo = &dev->geo;
struct pblk_line_mgmt *l_mg = &pblk->l_mg;
struct pblk_line_meta *lm = &pblk->lm;
struct pblk_emeta *emeta = meta_line->emeta;
struct pblk_g_ctx *m_ctx;
struct pblk_lun *rlun;
struct bio *bio;
struct nvm_rq *rqd;
void *data;
u64 paddr;
int rq_ppas = pblk->min_write_pgs;
int id = meta_line->id;
int rq_len;
int i, j;
int ret;
rqd = pblk_alloc_rqd(pblk, READ);
if (IS_ERR(rqd)) {
pr_err("pblk: cannot allocate write req.\n");
return PTR_ERR(rqd);
}
m_ctx = nvm_rq_to_pdu(rqd);
m_ctx->private = meta_line;
rq_len = rq_ppas * geo->sec_size;
data = ((void *)emeta->buf) + emeta->mem;
bio = pblk_bio_map_addr(pblk, data, rq_ppas, rq_len,
l_mg->emeta_alloc_type, GFP_KERNEL);
if (IS_ERR(bio)) {
ret = PTR_ERR(bio);
goto fail_free_rqd;
}
bio->bi_iter.bi_sector = 0; /* internal bio */
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
rqd->bio = bio;
ret = pblk_alloc_w_rq(pblk, rqd, rq_ppas, pblk_end_io_write_meta);
if (ret)
goto fail_free_bio;
for (i = 0; i < rqd->nr_ppas; ) {
spin_lock(&meta_line->lock);
paddr = __pblk_alloc_page(pblk, meta_line, rq_ppas);
spin_unlock(&meta_line->lock);
for (j = 0; j < rq_ppas; j++, i++, paddr++)
rqd->ppa_list[i] = addr_to_gen_ppa(pblk, paddr, id);
}
rlun = &pblk->luns[pblk_ppa_to_pos(geo, rqd->ppa_list[0])];
ret = down_timeout(&rlun->wr_sem, msecs_to_jiffies(5000));
if (ret) {
pr_err("pblk: lun semaphore timed out (%d)\n", ret);
goto fail_free_bio;
}
emeta->mem += rq_len;
if (emeta->mem >= lm->emeta_len[0]) {
spin_lock(&l_mg->close_lock);
list_del(&meta_line->list);
WARN(!bitmap_full(meta_line->map_bitmap, lm->sec_per_line),
"pblk: corrupt meta line %d\n", meta_line->id);
spin_unlock(&l_mg->close_lock);
}
ret = pblk_submit_io(pblk, rqd);
if (ret) {
pr_err("pblk: emeta I/O submission failed: %d\n", ret);
goto fail_rollback;
}
return NVM_IO_OK;
fail_rollback:
spin_lock(&l_mg->close_lock);
pblk_dealloc_page(pblk, meta_line, rq_ppas);
list_add(&meta_line->list, &meta_line->list);
spin_unlock(&l_mg->close_lock);
fail_free_bio:
if (likely(l_mg->emeta_alloc_type == PBLK_VMALLOC_META))
bio_put(bio);
fail_free_rqd:
pblk_free_rqd(pblk, rqd, READ);
return ret;
}
static int pblk_sched_meta_io(struct pblk *pblk, struct ppa_addr *prev_list,
int prev_n)
{
struct pblk_line_meta *lm = &pblk->lm;
struct pblk_line_mgmt *l_mg = &pblk->l_mg;
struct pblk_line *meta_line;
spin_lock(&l_mg->close_lock);
retry:
if (list_empty(&l_mg->emeta_list)) {
spin_unlock(&l_mg->close_lock);
return 0;
}
meta_line = list_first_entry(&l_mg->emeta_list, struct pblk_line, list);
if (bitmap_full(meta_line->map_bitmap, lm->sec_per_line))
goto retry;
spin_unlock(&l_mg->close_lock);
if (!pblk_valid_meta_ppa(pblk, meta_line, prev_list, prev_n))
return 0;
return pblk_submit_meta_io(pblk, meta_line);
}
static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
{
struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
struct ppa_addr erase_ppa;
int err;
ppa_set_empty(&erase_ppa);
/* Assign lbas to ppas and populate request structure */
err = pblk_setup_w_rq(pblk, rqd, c_ctx, &erase_ppa);
if (err) {
pr_err("pblk: could not setup write request: %d\n", err);
return NVM_IO_ERR;
}
if (likely(ppa_empty(erase_ppa))) {
/* Submit metadata write for previous data line */
err = pblk_sched_meta_io(pblk, rqd->ppa_list, rqd->nr_ppas);
if (err) {
pr_err("pblk: metadata I/O submission failed: %d", err);
return NVM_IO_ERR;
}
/* Submit data write for current data line */
err = pblk_submit_io(pblk, rqd);
if (err) {
pr_err("pblk: data I/O submission failed: %d\n", err);
return NVM_IO_ERR;
}
} else {
/* Submit data write for current data line */
err = pblk_submit_io(pblk, rqd);
if (err) {
pr_err("pblk: data I/O submission failed: %d\n", err);
return NVM_IO_ERR;
}
/* Submit available erase for next data line */
if (pblk_blk_erase_async(pblk, erase_ppa)) {
struct pblk_line *e_line = pblk_line_get_erase(pblk);
struct nvm_tgt_dev *dev = pblk->dev;
struct nvm_geo *geo = &dev->geo;
int bit;
atomic_inc(&e_line->left_eblks);
bit = pblk_ppa_to_pos(geo, erase_ppa);
WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
}
}
return NVM_IO_OK;
}
static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
{
struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
struct bio *bio = rqd->bio;
if (c_ctx->nr_padded)
pblk_bio_free_pages(pblk, bio, rqd->nr_ppas, c_ctx->nr_padded);
}
static int pblk_submit_write(struct pblk *pblk)
{
struct bio *bio;
struct nvm_rq *rqd;
unsigned int secs_avail, secs_to_sync, secs_to_com;
unsigned int secs_to_flush;
unsigned long pos;
/* If there are no sectors in the cache, flushes (bios without data)
* will be cleared on the cache threads
*/
secs_avail = pblk_rb_read_count(&pblk->rwb);
if (!secs_avail)
return 1;
secs_to_flush = pblk_rb_sync_point_count(&pblk->rwb);
if (!secs_to_flush && secs_avail < pblk->min_write_pgs)
return 1;
rqd = pblk_alloc_rqd(pblk, WRITE);
if (IS_ERR(rqd)) {
pr_err("pblk: cannot allocate write req.\n");
return 1;
}
bio = bio_alloc(GFP_KERNEL, pblk->max_write_pgs);
if (!bio) {
pr_err("pblk: cannot allocate write bio\n");
goto fail_free_rqd;
}
bio->bi_iter.bi_sector = 0; /* internal bio */
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
rqd->bio = bio;
secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail, secs_to_flush);
if (secs_to_sync > pblk->max_write_pgs) {
pr_err("pblk: bad buffer sync calculation\n");
goto fail_put_bio;
}
secs_to_com = (secs_to_sync > secs_avail) ? secs_avail : secs_to_sync;
pos = pblk_rb_read_commit(&pblk->rwb, secs_to_com);
if (pblk_rb_read_to_bio(&pblk->rwb, rqd, bio, pos, secs_to_sync,
secs_avail)) {
pr_err("pblk: corrupted write bio\n");
goto fail_put_bio;
}
if (pblk_submit_io_set(pblk, rqd))
goto fail_free_bio;
#ifdef CONFIG_NVM_DEBUG
atomic_long_add(secs_to_sync, &pblk->sub_writes);
#endif
return 0;
fail_free_bio:
pblk_free_write_rqd(pblk, rqd);
fail_put_bio:
bio_put(bio);
fail_free_rqd:
pblk_free_rqd(pblk, rqd, WRITE);
return 1;
}
int pblk_write_ts(void *data)
{
struct pblk *pblk = data;
while (!kthread_should_stop()) {
if (!pblk_submit_write(pblk))
continue;
set_current_state(TASK_INTERRUPTIBLE);
io_schedule();
}
return 0;
}