blob: 55e9442a99e2bfd664932d50a7a5b5ece9b9c9a8 [file] [log] [blame]
/*
* Copyright (C) 2016 CNEX Labs
* Initial release: Javier Gonzalez <javier@cnexlabs.com>
*
* Based upon the circular ringbuffer.
*
* 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-rb.c - pblk's write buffer
*/
#include <linux/circ_buf.h>
#include "pblk.h"
static DECLARE_RWSEM(pblk_rb_lock);
void pblk_rb_data_free(struct pblk_rb *rb)
{
struct pblk_rb_pages *p, *t;
down_write(&pblk_rb_lock);
list_for_each_entry_safe(p, t, &rb->pages, list) {
free_pages((unsigned long)page_address(p->pages), p->order);
list_del(&p->list);
kfree(p);
}
up_write(&pblk_rb_lock);
}
/*
* Initialize ring buffer. The data and metadata buffers must be previously
* allocated and their size must be a power of two
* (Documentation/core-api/circular-buffers.rst)
*/
int pblk_rb_init(struct pblk_rb *rb, struct pblk_rb_entry *rb_entry_base,
unsigned int power_size, unsigned int power_seg_sz)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
unsigned int init_entry = 0;
unsigned int alloc_order = power_size;
unsigned int max_order = MAX_ORDER - 1;
unsigned int order, iter;
down_write(&pblk_rb_lock);
rb->entries = rb_entry_base;
rb->seg_size = (1 << power_seg_sz);
rb->nr_entries = (1 << power_size);
rb->mem = rb->subm = rb->sync = rb->l2p_update = 0;
rb->flush_point = EMPTY_ENTRY;
spin_lock_init(&rb->w_lock);
spin_lock_init(&rb->s_lock);
INIT_LIST_HEAD(&rb->pages);
if (alloc_order >= max_order) {
order = max_order;
iter = (1 << (alloc_order - max_order));
} else {
order = alloc_order;
iter = 1;
}
do {
struct pblk_rb_entry *entry;
struct pblk_rb_pages *page_set;
void *kaddr;
unsigned long set_size;
int i;
page_set = kmalloc(sizeof(struct pblk_rb_pages), GFP_KERNEL);
if (!page_set) {
up_write(&pblk_rb_lock);
return -ENOMEM;
}
page_set->order = order;
page_set->pages = alloc_pages(GFP_KERNEL, order);
if (!page_set->pages) {
kfree(page_set);
pblk_rb_data_free(rb);
up_write(&pblk_rb_lock);
return -ENOMEM;
}
kaddr = page_address(page_set->pages);
entry = &rb->entries[init_entry];
entry->data = kaddr;
entry->cacheline = pblk_cacheline_to_addr(init_entry++);
entry->w_ctx.flags = PBLK_WRITABLE_ENTRY;
set_size = (1 << order);
for (i = 1; i < set_size; i++) {
entry = &rb->entries[init_entry];
entry->cacheline = pblk_cacheline_to_addr(init_entry++);
entry->data = kaddr + (i * rb->seg_size);
entry->w_ctx.flags = PBLK_WRITABLE_ENTRY;
bio_list_init(&entry->w_ctx.bios);
}
list_add_tail(&page_set->list, &rb->pages);
iter--;
} while (iter > 0);
up_write(&pblk_rb_lock);
#ifdef CONFIG_NVM_DEBUG
atomic_set(&rb->inflight_flush_point, 0);
#endif
/*
* Initialize rate-limiter, which controls access to the write buffer
* but user and GC I/O
*/
pblk_rl_init(&pblk->rl, rb->nr_entries);
return 0;
}
/*
* pblk_rb_calculate_size -- calculate the size of the write buffer
*/
unsigned int pblk_rb_calculate_size(unsigned int nr_entries)
{
/* Alloc a write buffer that can at least fit 128 entries */
return (1 << max(get_count_order(nr_entries), 7));
}
void *pblk_rb_entries_ref(struct pblk_rb *rb)
{
return rb->entries;
}
static void clean_wctx(struct pblk_w_ctx *w_ctx)
{
int flags;
flags = READ_ONCE(w_ctx->flags);
WARN_ONCE(!(flags & PBLK_SUBMITTED_ENTRY),
"pblk: overwriting unsubmitted data\n");
/* Release flags on context. Protect from writes and reads */
smp_store_release(&w_ctx->flags, PBLK_WRITABLE_ENTRY);
pblk_ppa_set_empty(&w_ctx->ppa);
w_ctx->lba = ADDR_EMPTY;
}
#define pblk_rb_ring_count(head, tail, size) CIRC_CNT(head, tail, size)
#define pblk_rb_ring_space(rb, head, tail, size) \
(CIRC_SPACE(head, tail, size))
/*
* Buffer space is calculated with respect to the back pointer signaling
* synchronized entries to the media.
*/
static unsigned int pblk_rb_space(struct pblk_rb *rb)
{
unsigned int mem = READ_ONCE(rb->mem);
unsigned int sync = READ_ONCE(rb->sync);
return pblk_rb_ring_space(rb, mem, sync, rb->nr_entries);
}
/*
* Buffer count is calculated with respect to the submission entry signaling the
* entries that are available to send to the media
*/
unsigned int pblk_rb_read_count(struct pblk_rb *rb)
{
unsigned int mem = READ_ONCE(rb->mem);
unsigned int subm = READ_ONCE(rb->subm);
return pblk_rb_ring_count(mem, subm, rb->nr_entries);
}
unsigned int pblk_rb_sync_count(struct pblk_rb *rb)
{
unsigned int mem = READ_ONCE(rb->mem);
unsigned int sync = READ_ONCE(rb->sync);
return pblk_rb_ring_count(mem, sync, rb->nr_entries);
}
unsigned int pblk_rb_read_commit(struct pblk_rb *rb, unsigned int nr_entries)
{
unsigned int subm;
subm = READ_ONCE(rb->subm);
/* Commit read means updating submission pointer */
smp_store_release(&rb->subm,
(subm + nr_entries) & (rb->nr_entries - 1));
return subm;
}
static int __pblk_rb_update_l2p(struct pblk_rb *rb, unsigned int to_update)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
struct pblk_line *line;
struct pblk_rb_entry *entry;
struct pblk_w_ctx *w_ctx;
unsigned int user_io = 0, gc_io = 0;
unsigned int i;
int flags;
for (i = 0; i < to_update; i++) {
entry = &rb->entries[rb->l2p_update];
w_ctx = &entry->w_ctx;
flags = READ_ONCE(entry->w_ctx.flags);
if (flags & PBLK_IOTYPE_USER)
user_io++;
else if (flags & PBLK_IOTYPE_GC)
gc_io++;
else
WARN(1, "pblk: unknown IO type\n");
pblk_update_map_dev(pblk, w_ctx->lba, w_ctx->ppa,
entry->cacheline);
line = &pblk->lines[pblk_ppa_to_line(w_ctx->ppa)];
kref_put(&line->ref, pblk_line_put);
clean_wctx(w_ctx);
rb->l2p_update = (rb->l2p_update + 1) & (rb->nr_entries - 1);
}
pblk_rl_out(&pblk->rl, user_io, gc_io);
return 0;
}
/*
* When we move the l2p_update pointer, we update the l2p table - lookups will
* point to the physical address instead of to the cacheline in the write buffer
* from this moment on.
*/
static int pblk_rb_update_l2p(struct pblk_rb *rb, unsigned int nr_entries,
unsigned int mem, unsigned int sync)
{
unsigned int space, count;
int ret = 0;
lockdep_assert_held(&rb->w_lock);
/* Update l2p only as buffer entries are being overwritten */
space = pblk_rb_ring_space(rb, mem, rb->l2p_update, rb->nr_entries);
if (space > nr_entries)
goto out;
count = nr_entries - space;
/* l2p_update used exclusively under rb->w_lock */
ret = __pblk_rb_update_l2p(rb, count);
out:
return ret;
}
/*
* Update the l2p entry for all sectors stored on the write buffer. This means
* that all future lookups to the l2p table will point to a device address, not
* to the cacheline in the write buffer.
*/
void pblk_rb_sync_l2p(struct pblk_rb *rb)
{
unsigned int sync;
unsigned int to_update;
spin_lock(&rb->w_lock);
/* Protect from reads and writes */
sync = smp_load_acquire(&rb->sync);
to_update = pblk_rb_ring_count(sync, rb->l2p_update, rb->nr_entries);
__pblk_rb_update_l2p(rb, to_update);
spin_unlock(&rb->w_lock);
}
/*
* Write @nr_entries to ring buffer from @data buffer if there is enough space.
* Typically, 4KB data chunks coming from a bio will be copied to the ring
* buffer, thus the write will fail if not all incoming data can be copied.
*
*/
static void __pblk_rb_write_entry(struct pblk_rb *rb, void *data,
struct pblk_w_ctx w_ctx,
struct pblk_rb_entry *entry)
{
memcpy(entry->data, data, rb->seg_size);
entry->w_ctx.lba = w_ctx.lba;
entry->w_ctx.ppa = w_ctx.ppa;
}
void pblk_rb_write_entry_user(struct pblk_rb *rb, void *data,
struct pblk_w_ctx w_ctx, unsigned int ring_pos)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
struct pblk_rb_entry *entry;
int flags;
entry = &rb->entries[ring_pos];
flags = READ_ONCE(entry->w_ctx.flags);
#ifdef CONFIG_NVM_DEBUG
/* Caller must guarantee that the entry is free */
BUG_ON(!(flags & PBLK_WRITABLE_ENTRY));
#endif
__pblk_rb_write_entry(rb, data, w_ctx, entry);
pblk_update_map_cache(pblk, w_ctx.lba, entry->cacheline);
flags = w_ctx.flags | PBLK_WRITTEN_DATA;
/* Release flags on write context. Protect from writes */
smp_store_release(&entry->w_ctx.flags, flags);
}
void pblk_rb_write_entry_gc(struct pblk_rb *rb, void *data,
struct pblk_w_ctx w_ctx, struct pblk_line *line,
u64 paddr, unsigned int ring_pos)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
struct pblk_rb_entry *entry;
int flags;
entry = &rb->entries[ring_pos];
flags = READ_ONCE(entry->w_ctx.flags);
#ifdef CONFIG_NVM_DEBUG
/* Caller must guarantee that the entry is free */
BUG_ON(!(flags & PBLK_WRITABLE_ENTRY));
#endif
__pblk_rb_write_entry(rb, data, w_ctx, entry);
if (!pblk_update_map_gc(pblk, w_ctx.lba, entry->cacheline, line, paddr))
entry->w_ctx.lba = ADDR_EMPTY;
flags = w_ctx.flags | PBLK_WRITTEN_DATA;
/* Release flags on write context. Protect from writes */
smp_store_release(&entry->w_ctx.flags, flags);
}
static int pblk_rb_flush_point_set(struct pblk_rb *rb, struct bio *bio,
unsigned int pos)
{
struct pblk_rb_entry *entry;
unsigned int sync, flush_point;
pblk_rb_sync_init(rb, NULL);
sync = READ_ONCE(rb->sync);
if (pos == sync) {
pblk_rb_sync_end(rb, NULL);
return 0;
}
#ifdef CONFIG_NVM_DEBUG
atomic_inc(&rb->inflight_flush_point);
#endif
flush_point = (pos == 0) ? (rb->nr_entries - 1) : (pos - 1);
entry = &rb->entries[flush_point];
/* Protect flush points */
smp_store_release(&rb->flush_point, flush_point);
if (bio)
bio_list_add(&entry->w_ctx.bios, bio);
pblk_rb_sync_end(rb, NULL);
return bio ? 1 : 0;
}
static int __pblk_rb_may_write(struct pblk_rb *rb, unsigned int nr_entries,
unsigned int *pos)
{
unsigned int mem;
unsigned int sync;
sync = READ_ONCE(rb->sync);
mem = READ_ONCE(rb->mem);
if (pblk_rb_ring_space(rb, mem, sync, rb->nr_entries) < nr_entries)
return 0;
if (pblk_rb_update_l2p(rb, nr_entries, mem, sync))
return 0;
*pos = mem;
return 1;
}
static int pblk_rb_may_write(struct pblk_rb *rb, unsigned int nr_entries,
unsigned int *pos)
{
if (!__pblk_rb_may_write(rb, nr_entries, pos))
return 0;
/* Protect from read count */
smp_store_release(&rb->mem, (*pos + nr_entries) & (rb->nr_entries - 1));
return 1;
}
void pblk_rb_flush(struct pblk_rb *rb)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
unsigned int mem = READ_ONCE(rb->mem);
if (pblk_rb_flush_point_set(rb, NULL, mem))
return;
pblk_write_kick(pblk);
}
static int pblk_rb_may_write_flush(struct pblk_rb *rb, unsigned int nr_entries,
unsigned int *pos, struct bio *bio,
int *io_ret)
{
unsigned int mem;
if (!__pblk_rb_may_write(rb, nr_entries, pos))
return 0;
mem = (*pos + nr_entries) & (rb->nr_entries - 1);
*io_ret = NVM_IO_DONE;
if (bio->bi_opf & REQ_PREFLUSH) {
struct pblk *pblk = container_of(rb, struct pblk, rwb);
atomic64_inc(&pblk->nr_flush);
if (pblk_rb_flush_point_set(&pblk->rwb, bio, mem))
*io_ret = NVM_IO_OK;
}
/* Protect from read count */
smp_store_release(&rb->mem, mem);
return 1;
}
/*
* Atomically check that (i) there is space on the write buffer for the
* incoming I/O, and (ii) the current I/O type has enough budget in the write
* buffer (rate-limiter).
*/
int pblk_rb_may_write_user(struct pblk_rb *rb, struct bio *bio,
unsigned int nr_entries, unsigned int *pos)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
int io_ret;
spin_lock(&rb->w_lock);
io_ret = pblk_rl_user_may_insert(&pblk->rl, nr_entries);
if (io_ret) {
spin_unlock(&rb->w_lock);
return io_ret;
}
if (!pblk_rb_may_write_flush(rb, nr_entries, pos, bio, &io_ret)) {
spin_unlock(&rb->w_lock);
return NVM_IO_REQUEUE;
}
pblk_rl_user_in(&pblk->rl, nr_entries);
spin_unlock(&rb->w_lock);
return io_ret;
}
/*
* Look at pblk_rb_may_write_user comment
*/
int pblk_rb_may_write_gc(struct pblk_rb *rb, unsigned int nr_entries,
unsigned int *pos)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
spin_lock(&rb->w_lock);
if (!pblk_rl_gc_may_insert(&pblk->rl, nr_entries)) {
spin_unlock(&rb->w_lock);
return 0;
}
if (!pblk_rb_may_write(rb, nr_entries, pos)) {
spin_unlock(&rb->w_lock);
return 0;
}
pblk_rl_gc_in(&pblk->rl, nr_entries);
spin_unlock(&rb->w_lock);
return 1;
}
/*
* Read available entries on rb and add them to the given bio. To avoid a memory
* copy, a page reference to the write buffer is used to be added to the bio.
*
* This function is used by the write thread to form the write bio that will
* persist data on the write buffer to the media.
*/
unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
unsigned int pos, unsigned int nr_entries,
unsigned int count)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
struct request_queue *q = pblk->dev->q;
struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
struct bio *bio = rqd->bio;
struct pblk_rb_entry *entry;
struct page *page;
unsigned int pad = 0, to_read = nr_entries;
unsigned int i;
int flags;
if (count < nr_entries) {
pad = nr_entries - count;
to_read = count;
}
c_ctx->sentry = pos;
c_ctx->nr_valid = to_read;
c_ctx->nr_padded = pad;
for (i = 0; i < to_read; i++) {
entry = &rb->entries[pos];
/* A write has been allowed into the buffer, but data is still
* being copied to it. It is ok to busy wait.
*/
try:
flags = READ_ONCE(entry->w_ctx.flags);
if (!(flags & PBLK_WRITTEN_DATA)) {
io_schedule();
goto try;
}
page = virt_to_page(entry->data);
if (!page) {
pr_err("pblk: could not allocate write bio page\n");
flags &= ~PBLK_WRITTEN_DATA;
flags |= PBLK_SUBMITTED_ENTRY;
/* Release flags on context. Protect from writes */
smp_store_release(&entry->w_ctx.flags, flags);
return NVM_IO_ERR;
}
if (bio_add_pc_page(q, bio, page, rb->seg_size, 0) !=
rb->seg_size) {
pr_err("pblk: could not add page to write bio\n");
flags &= ~PBLK_WRITTEN_DATA;
flags |= PBLK_SUBMITTED_ENTRY;
/* Release flags on context. Protect from writes */
smp_store_release(&entry->w_ctx.flags, flags);
return NVM_IO_ERR;
}
flags &= ~PBLK_WRITTEN_DATA;
flags |= PBLK_SUBMITTED_ENTRY;
/* Release flags on context. Protect from writes */
smp_store_release(&entry->w_ctx.flags, flags);
pos = (pos + 1) & (rb->nr_entries - 1);
}
if (pad) {
if (pblk_bio_add_pages(pblk, bio, GFP_KERNEL, pad)) {
pr_err("pblk: could not pad page in write bio\n");
return NVM_IO_ERR;
}
if (pad < pblk->min_write_pgs)
atomic64_inc(&pblk->pad_dist[pad - 1]);
else
pr_warn("pblk: padding more than min. sectors\n");
atomic64_add(pad, &pblk->pad_wa);
}
#ifdef CONFIG_NVM_DEBUG
atomic_long_add(pad, &pblk->padded_writes);
#endif
return NVM_IO_OK;
}
/*
* Copy to bio only if the lba matches the one on the given cache entry.
* Otherwise, it means that the entry has been overwritten, and the bio should
* be directed to disk.
*/
int pblk_rb_copy_to_bio(struct pblk_rb *rb, struct bio *bio, sector_t lba,
struct ppa_addr ppa, int bio_iter, bool advanced_bio)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
struct pblk_rb_entry *entry;
struct pblk_w_ctx *w_ctx;
struct ppa_addr l2p_ppa;
u64 pos = pblk_addr_to_cacheline(ppa);
void *data;
int flags;
int ret = 1;
#ifdef CONFIG_NVM_DEBUG
/* Caller must ensure that the access will not cause an overflow */
BUG_ON(pos >= rb->nr_entries);
#endif
entry = &rb->entries[pos];
w_ctx = &entry->w_ctx;
flags = READ_ONCE(w_ctx->flags);
spin_lock(&rb->w_lock);
spin_lock(&pblk->trans_lock);
l2p_ppa = pblk_trans_map_get(pblk, lba);
spin_unlock(&pblk->trans_lock);
/* Check if the entry has been overwritten or is scheduled to be */
if (!pblk_ppa_comp(l2p_ppa, ppa) || w_ctx->lba != lba ||
flags & PBLK_WRITABLE_ENTRY) {
ret = 0;
goto out;
}
/* Only advance the bio if it hasn't been advanced already. If advanced,
* this bio is at least a partial bio (i.e., it has partially been
* filled with data from the cache). If part of the data resides on the
* media, we will read later on
*/
if (unlikely(!advanced_bio))
bio_advance(bio, bio_iter * PBLK_EXPOSED_PAGE_SIZE);
data = bio_data(bio);
memcpy(data, entry->data, rb->seg_size);
out:
spin_unlock(&rb->w_lock);
return ret;
}
struct pblk_w_ctx *pblk_rb_w_ctx(struct pblk_rb *rb, unsigned int pos)
{
unsigned int entry = pos & (rb->nr_entries - 1);
return &rb->entries[entry].w_ctx;
}
unsigned int pblk_rb_sync_init(struct pblk_rb *rb, unsigned long *flags)
__acquires(&rb->s_lock)
{
if (flags)
spin_lock_irqsave(&rb->s_lock, *flags);
else
spin_lock_irq(&rb->s_lock);
return rb->sync;
}
void pblk_rb_sync_end(struct pblk_rb *rb, unsigned long *flags)
__releases(&rb->s_lock)
{
lockdep_assert_held(&rb->s_lock);
if (flags)
spin_unlock_irqrestore(&rb->s_lock, *flags);
else
spin_unlock_irq(&rb->s_lock);
}
unsigned int pblk_rb_sync_advance(struct pblk_rb *rb, unsigned int nr_entries)
{
unsigned int sync, flush_point;
lockdep_assert_held(&rb->s_lock);
sync = READ_ONCE(rb->sync);
flush_point = READ_ONCE(rb->flush_point);
if (flush_point != EMPTY_ENTRY) {
unsigned int secs_to_flush;
secs_to_flush = pblk_rb_ring_count(flush_point, sync,
rb->nr_entries);
if (secs_to_flush < nr_entries) {
/* Protect flush points */
smp_store_release(&rb->flush_point, EMPTY_ENTRY);
}
}
sync = (sync + nr_entries) & (rb->nr_entries - 1);
/* Protect from counts */
smp_store_release(&rb->sync, sync);
return sync;
}
/* Calculate how many sectors to submit up to the current flush point. */
unsigned int pblk_rb_flush_point_count(struct pblk_rb *rb)
{
unsigned int subm, sync, flush_point;
unsigned int submitted, to_flush;
/* Protect flush points */
flush_point = smp_load_acquire(&rb->flush_point);
if (flush_point == EMPTY_ENTRY)
return 0;
/* Protect syncs */
sync = smp_load_acquire(&rb->sync);
subm = READ_ONCE(rb->subm);
submitted = pblk_rb_ring_count(subm, sync, rb->nr_entries);
/* The sync point itself counts as a sector to sync */
to_flush = pblk_rb_ring_count(flush_point, sync, rb->nr_entries) + 1;
return (submitted < to_flush) ? (to_flush - submitted) : 0;
}
/*
* Scan from the current position of the sync pointer to find the entry that
* corresponds to the given ppa. This is necessary since write requests can be
* completed out of order. The assumption is that the ppa is close to the sync
* pointer thus the search will not take long.
*
* The caller of this function must guarantee that the sync pointer will no
* reach the entry while it is using the metadata associated with it. With this
* assumption in mind, there is no need to take the sync lock.
*/
struct pblk_rb_entry *pblk_rb_sync_scan_entry(struct pblk_rb *rb,
struct ppa_addr *ppa)
{
unsigned int sync, subm, count;
unsigned int i;
sync = READ_ONCE(rb->sync);
subm = READ_ONCE(rb->subm);
count = pblk_rb_ring_count(subm, sync, rb->nr_entries);
for (i = 0; i < count; i++)
sync = (sync + 1) & (rb->nr_entries - 1);
return NULL;
}
int pblk_rb_tear_down_check(struct pblk_rb *rb)
{
struct pblk_rb_entry *entry;
int i;
int ret = 0;
spin_lock(&rb->w_lock);
spin_lock_irq(&rb->s_lock);
if ((rb->mem == rb->subm) && (rb->subm == rb->sync) &&
(rb->sync == rb->l2p_update) &&
(rb->flush_point == EMPTY_ENTRY)) {
goto out;
}
if (!rb->entries) {
ret = 1;
goto out;
}
for (i = 0; i < rb->nr_entries; i++) {
entry = &rb->entries[i];
if (!entry->data) {
ret = 1;
goto out;
}
}
out:
spin_unlock(&rb->w_lock);
spin_unlock_irq(&rb->s_lock);
return ret;
}
unsigned int pblk_rb_wrap_pos(struct pblk_rb *rb, unsigned int pos)
{
return (pos & (rb->nr_entries - 1));
}
int pblk_rb_pos_oob(struct pblk_rb *rb, u64 pos)
{
return (pos >= rb->nr_entries);
}
ssize_t pblk_rb_sysfs(struct pblk_rb *rb, char *buf)
{
struct pblk *pblk = container_of(rb, struct pblk, rwb);
struct pblk_c_ctx *c;
ssize_t offset;
int queued_entries = 0;
spin_lock_irq(&rb->s_lock);
list_for_each_entry(c, &pblk->compl_list, list)
queued_entries++;
spin_unlock_irq(&rb->s_lock);
if (rb->flush_point != EMPTY_ENTRY)
offset = scnprintf(buf, PAGE_SIZE,
"%u\t%u\t%u\t%u\t%u\t%u\t%u - %u/%u/%u - %d\n",
rb->nr_entries,
rb->mem,
rb->subm,
rb->sync,
rb->l2p_update,
#ifdef CONFIG_NVM_DEBUG
atomic_read(&rb->inflight_flush_point),
#else
0,
#endif
rb->flush_point,
pblk_rb_read_count(rb),
pblk_rb_space(rb),
pblk_rb_flush_point_count(rb),
queued_entries);
else
offset = scnprintf(buf, PAGE_SIZE,
"%u\t%u\t%u\t%u\t%u\t%u\tNULL - %u/%u/%u - %d\n",
rb->nr_entries,
rb->mem,
rb->subm,
rb->sync,
rb->l2p_update,
#ifdef CONFIG_NVM_DEBUG
atomic_read(&rb->inflight_flush_point),
#else
0,
#endif
pblk_rb_read_count(rb),
pblk_rb_space(rb),
pblk_rb_flush_point_count(rb),
queued_entries);
return offset;
}