linux/drivers/lightnvm/pblk-write.c
Javier González a44f53faf4 lightnvm: pblk: fix erase counters on error fail
When block erases fail, these blocks are marked bad. The number of valid
blocks in the line was not updated, which could cause an infinite loop
on the erase path.

Fix this atomic counter and, in order to avoid taking an irq lock on the
interrupt context, make the erase counters atomic too.

Also, in the case that a significant number of blocks become bad in a
line, the result is the double shared metadata buffer (emeta) to stop
the pipeline until all metadata is flushed to the media. Increase the
number of metadata lines from 2 to 4 to avoid this case.

Fixes: a4bd217b43 "lightnvm: physical block device (pblk) target"

Signed-off-by: Javier González <javier@cnexlabs.com>
Reviewed-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-23 16:57:52 -06:00

415 lines
10 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 void pblk_sync_line(struct pblk *pblk, struct pblk_line *line)
{
#ifdef CONFIG_NVM_DEBUG
atomic_long_inc(&pblk->sync_writes);
#endif
/* Counter protected by rb sync lock */
line->left_ssecs--;
if (!line->left_ssecs)
pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws);
}
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;
struct ppa_addr p;
struct pblk_line *line;
w_ctx = pblk_rb_w_ctx(&pblk->rwb, c_ctx->sentry + i);
p = rqd->ppa_list[i];
line = &pblk->lines[pblk_dev_ppa_to_line(p)];
pblk_sync_line(pblk, line);
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->compl_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->kw_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_error, "pblk: corrupted write error\n");
#endif
pblk_complete_write(pblk, rqd, c_ctx);
}
static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
unsigned int nr_secs)
{
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 = pblk_end_io_write;
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 pblk_line_meta *lm = &pblk->lm;
struct pblk_line *e_line = pblk_line_get_data_next(pblk);
struct ppa_addr erase_ppa;
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) {
ret = -ENOMEM;
goto out;
}
c_ctx->lun_bitmap = lun_bitmap;
ret = pblk_alloc_w_rq(pblk, rqd, nr_secs);
if (ret) {
kfree(lun_bitmap);
goto out;
}
ppa_set_empty(&erase_ppa);
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);
out:
if (unlikely(e_line && !ppa_empty(erase_ppa))) {
if (pblk_blk_erase_async(pblk, erase_ppa)) {
struct nvm_tgt_dev *dev = pblk->dev;
struct nvm_geo *geo = &dev->geo;
int bit;
atomic_inc(&e_line->left_eblks);
bit = erase_ppa.g.lun * geo->nr_chnls + erase_ppa.g.ch;
WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
up(&pblk->erase_sem);
}
}
return ret;
}
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);
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 int pblk_submit_write(struct pblk *pblk)
{
struct bio *bio;
struct nvm_rq *rqd;
struct pblk_c_ctx *c_ctx;
unsigned int pgs_read;
unsigned int secs_avail, secs_to_sync, secs_to_com;
unsigned int secs_to_flush;
unsigned long pos;
int err;
/* 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;
}
c_ctx = nvm_rq_to_pdu(rqd);
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);
pgs_read = pblk_rb_read_to_bio(&pblk->rwb, bio, c_ctx, pos,
secs_to_sync, secs_avail);
if (!pgs_read) {
pr_err("pblk: corrupted write bio\n");
goto fail_put_bio;
}
if (c_ctx->nr_padded)
if (pblk_bio_add_pages(pblk, bio, GFP_KERNEL, c_ctx->nr_padded))
goto fail_put_bio;
/* Assign lbas to ppas and populate request structure */
err = pblk_setup_w_rq(pblk, rqd, c_ctx);
if (err) {
pr_err("pblk: could not setup write request\n");
goto fail_free_bio;
}
err = pblk_submit_io(pblk, rqd);
if (err) {
pr_err("pblk: I/O submission failed: %d\n", err);
goto fail_free_bio;
}
#ifdef CONFIG_NVM_DEBUG
atomic_long_add(secs_to_sync, &pblk->sub_writes);
#endif
return 0;
fail_free_bio:
if (c_ctx->nr_padded)
pblk_bio_free_pages(pblk, bio, secs_to_sync, c_ctx->nr_padded);
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;
}