diff options
Diffstat (limited to 'drivers/md/bcache/journal.c')
| -rw-r--r-- | drivers/md/bcache/journal.c | 1000 |
1 files changed, 1000 insertions, 0 deletions
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c new file mode 100644 index 0000000000..c182c21de2 --- /dev/null +++ b/drivers/md/bcache/journal.c @@ -0,0 +1,1000 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * bcache journalling code, for btree insertions + * + * Copyright 2012 Google, Inc. + */ + +#include "bcache.h" +#include "btree.h" +#include "debug.h" +#include "extents.h" + +#include <trace/events/bcache.h> + +/* + * Journal replay/recovery: + * + * This code is all driven from run_cache_set(); we first read the journal + * entries, do some other stuff, then we mark all the keys in the journal + * entries (same as garbage collection would), then we replay them - reinserting + * them into the cache in precisely the same order as they appear in the + * journal. + * + * We only journal keys that go in leaf nodes, which simplifies things quite a + * bit. + */ + +static void journal_read_endio(struct bio *bio) +{ + struct closure *cl = bio->bi_private; + + closure_put(cl); +} + +static int journal_read_bucket(struct cache *ca, struct list_head *list, + unsigned int bucket_index) +{ + struct journal_device *ja = &ca->journal; + struct bio *bio = &ja->bio; + + struct journal_replay *i; + struct jset *j, *data = ca->set->journal.w[0].data; + struct closure cl; + unsigned int len, left, offset = 0; + int ret = 0; + sector_t bucket = bucket_to_sector(ca->set, ca->sb.d[bucket_index]); + + closure_init_stack(&cl); + + pr_debug("reading %u\n", bucket_index); + + while (offset < ca->sb.bucket_size) { +reread: left = ca->sb.bucket_size - offset; + len = min_t(unsigned int, left, PAGE_SECTORS << JSET_BITS); + + bio_reset(bio, ca->bdev, REQ_OP_READ); + bio->bi_iter.bi_sector = bucket + offset; + bio->bi_iter.bi_size = len << 9; + + bio->bi_end_io = journal_read_endio; + bio->bi_private = &cl; + bch_bio_map(bio, data); + + closure_bio_submit(ca->set, bio, &cl); + closure_sync(&cl); + + /* This function could be simpler now since we no longer write + * journal entries that overlap bucket boundaries; this means + * the start of a bucket will always have a valid journal entry + * if it has any journal entries at all. + */ + + j = data; + while (len) { + struct list_head *where; + size_t blocks, bytes = set_bytes(j); + + if (j->magic != jset_magic(&ca->sb)) { + pr_debug("%u: bad magic\n", bucket_index); + return ret; + } + + if (bytes > left << 9 || + bytes > PAGE_SIZE << JSET_BITS) { + pr_info("%u: too big, %zu bytes, offset %u\n", + bucket_index, bytes, offset); + return ret; + } + + if (bytes > len << 9) + goto reread; + + if (j->csum != csum_set(j)) { + pr_info("%u: bad csum, %zu bytes, offset %u\n", + bucket_index, bytes, offset); + return ret; + } + + blocks = set_blocks(j, block_bytes(ca)); + + /* + * Nodes in 'list' are in linear increasing order of + * i->j.seq, the node on head has the smallest (oldest) + * journal seq, the node on tail has the biggest + * (latest) journal seq. + */ + + /* + * Check from the oldest jset for last_seq. If + * i->j.seq < j->last_seq, it means the oldest jset + * in list is expired and useless, remove it from + * this list. Otherwise, j is a candidate jset for + * further following checks. + */ + while (!list_empty(list)) { + i = list_first_entry(list, + struct journal_replay, list); + if (i->j.seq >= j->last_seq) + break; + list_del(&i->list); + kfree(i); + } + + /* iterate list in reverse order (from latest jset) */ + list_for_each_entry_reverse(i, list, list) { + if (j->seq == i->j.seq) + goto next_set; + + /* + * if j->seq is less than any i->j.last_seq + * in list, j is an expired and useless jset. + */ + if (j->seq < i->j.last_seq) + goto next_set; + + /* + * 'where' points to first jset in list which + * is elder then j. + */ + if (j->seq > i->j.seq) { + where = &i->list; + goto add; + } + } + + where = list; +add: + i = kmalloc(offsetof(struct journal_replay, j) + + bytes, GFP_KERNEL); + if (!i) + return -ENOMEM; + unsafe_memcpy(&i->j, j, bytes, + /* "bytes" was calculated by set_bytes() above */); + /* Add to the location after 'where' points to */ + list_add(&i->list, where); + ret = 1; + + if (j->seq > ja->seq[bucket_index]) + ja->seq[bucket_index] = j->seq; +next_set: + offset += blocks * ca->sb.block_size; + len -= blocks * ca->sb.block_size; + j = ((void *) j) + blocks * block_bytes(ca); + } + } + + return ret; +} + +int bch_journal_read(struct cache_set *c, struct list_head *list) +{ +#define read_bucket(b) \ + ({ \ + ret = journal_read_bucket(ca, list, b); \ + __set_bit(b, bitmap); \ + if (ret < 0) \ + return ret; \ + ret; \ + }) + + struct cache *ca = c->cache; + int ret = 0; + struct journal_device *ja = &ca->journal; + DECLARE_BITMAP(bitmap, SB_JOURNAL_BUCKETS); + unsigned int i, l, r, m; + uint64_t seq; + + bitmap_zero(bitmap, SB_JOURNAL_BUCKETS); + pr_debug("%u journal buckets\n", ca->sb.njournal_buckets); + + /* + * Read journal buckets ordered by golden ratio hash to quickly + * find a sequence of buckets with valid journal entries + */ + for (i = 0; i < ca->sb.njournal_buckets; i++) { + /* + * We must try the index l with ZERO first for + * correctness due to the scenario that the journal + * bucket is circular buffer which might have wrapped + */ + l = (i * 2654435769U) % ca->sb.njournal_buckets; + + if (test_bit(l, bitmap)) + break; + + if (read_bucket(l)) + goto bsearch; + } + + /* + * If that fails, check all the buckets we haven't checked + * already + */ + pr_debug("falling back to linear search\n"); + + for_each_clear_bit(l, bitmap, ca->sb.njournal_buckets) + if (read_bucket(l)) + goto bsearch; + + /* no journal entries on this device? */ + if (l == ca->sb.njournal_buckets) + goto out; +bsearch: + BUG_ON(list_empty(list)); + + /* Binary search */ + m = l; + r = find_next_bit(bitmap, ca->sb.njournal_buckets, l + 1); + pr_debug("starting binary search, l %u r %u\n", l, r); + + while (l + 1 < r) { + seq = list_entry(list->prev, struct journal_replay, + list)->j.seq; + + m = (l + r) >> 1; + read_bucket(m); + + if (seq != list_entry(list->prev, struct journal_replay, + list)->j.seq) + l = m; + else + r = m; + } + + /* + * Read buckets in reverse order until we stop finding more + * journal entries + */ + pr_debug("finishing up: m %u njournal_buckets %u\n", + m, ca->sb.njournal_buckets); + l = m; + + while (1) { + if (!l--) + l = ca->sb.njournal_buckets - 1; + + if (l == m) + break; + + if (test_bit(l, bitmap)) + continue; + + if (!read_bucket(l)) + break; + } + + seq = 0; + + for (i = 0; i < ca->sb.njournal_buckets; i++) + if (ja->seq[i] > seq) { + seq = ja->seq[i]; + /* + * When journal_reclaim() goes to allocate for + * the first time, it'll use the bucket after + * ja->cur_idx + */ + ja->cur_idx = i; + ja->last_idx = ja->discard_idx = (i + 1) % + ca->sb.njournal_buckets; + + } + +out: + if (!list_empty(list)) + c->journal.seq = list_entry(list->prev, + struct journal_replay, + list)->j.seq; + + return 0; +#undef read_bucket +} + +void bch_journal_mark(struct cache_set *c, struct list_head *list) +{ + atomic_t p = { 0 }; + struct bkey *k; + struct journal_replay *i; + struct journal *j = &c->journal; + uint64_t last = j->seq; + + /* + * journal.pin should never fill up - we never write a journal + * entry when it would fill up. But if for some reason it does, we + * iterate over the list in reverse order so that we can just skip that + * refcount instead of bugging. + */ + + list_for_each_entry_reverse(i, list, list) { + BUG_ON(last < i->j.seq); + i->pin = NULL; + + while (last-- != i->j.seq) + if (fifo_free(&j->pin) > 1) { + fifo_push_front(&j->pin, p); + atomic_set(&fifo_front(&j->pin), 0); + } + + if (fifo_free(&j->pin) > 1) { + fifo_push_front(&j->pin, p); + i->pin = &fifo_front(&j->pin); + atomic_set(i->pin, 1); + } + + for (k = i->j.start; + k < bset_bkey_last(&i->j); + k = bkey_next(k)) + if (!__bch_extent_invalid(c, k)) { + unsigned int j; + + for (j = 0; j < KEY_PTRS(k); j++) + if (ptr_available(c, k, j)) + atomic_inc(&PTR_BUCKET(c, k, j)->pin); + + bch_initial_mark_key(c, 0, k); + } + } +} + +static bool is_discard_enabled(struct cache_set *s) +{ + struct cache *ca = s->cache; + + if (ca->discard) + return true; + + return false; +} + +int bch_journal_replay(struct cache_set *s, struct list_head *list) +{ + int ret = 0, keys = 0, entries = 0; + struct bkey *k; + struct journal_replay *i = + list_entry(list->prev, struct journal_replay, list); + + uint64_t start = i->j.last_seq, end = i->j.seq, n = start; + struct keylist keylist; + + list_for_each_entry(i, list, list) { + BUG_ON(i->pin && atomic_read(i->pin) != 1); + + if (n != i->j.seq) { + if (n == start && is_discard_enabled(s)) + pr_info("journal entries %llu-%llu may be discarded! (replaying %llu-%llu)\n", + n, i->j.seq - 1, start, end); + else { + pr_err("journal entries %llu-%llu missing! (replaying %llu-%llu)\n", + n, i->j.seq - 1, start, end); + ret = -EIO; + goto err; + } + } + + for (k = i->j.start; + k < bset_bkey_last(&i->j); + k = bkey_next(k)) { + trace_bcache_journal_replay_key(k); + + bch_keylist_init_single(&keylist, k); + + ret = bch_btree_insert(s, &keylist, i->pin, NULL); + if (ret) + goto err; + + BUG_ON(!bch_keylist_empty(&keylist)); + keys++; + + cond_resched(); + } + + if (i->pin) + atomic_dec(i->pin); + n = i->j.seq + 1; + entries++; + } + + pr_info("journal replay done, %i keys in %i entries, seq %llu\n", + keys, entries, end); +err: + while (!list_empty(list)) { + i = list_first_entry(list, struct journal_replay, list); + list_del(&i->list); + kfree(i); + } + + return ret; +} + +void bch_journal_space_reserve(struct journal *j) +{ + j->do_reserve = true; +} + +/* Journalling */ + +static void btree_flush_write(struct cache_set *c) +{ + struct btree *b, *t, *btree_nodes[BTREE_FLUSH_NR]; + unsigned int i, nr; + int ref_nr; + atomic_t *fifo_front_p, *now_fifo_front_p; + size_t mask; + + if (c->journal.btree_flushing) + return; + + spin_lock(&c->journal.flush_write_lock); + if (c->journal.btree_flushing) { + spin_unlock(&c->journal.flush_write_lock); + return; + } + c->journal.btree_flushing = true; + spin_unlock(&c->journal.flush_write_lock); + + /* get the oldest journal entry and check its refcount */ + spin_lock(&c->journal.lock); + fifo_front_p = &fifo_front(&c->journal.pin); + ref_nr = atomic_read(fifo_front_p); + if (ref_nr <= 0) { + /* + * do nothing if no btree node references + * the oldest journal entry + */ + spin_unlock(&c->journal.lock); + goto out; + } + spin_unlock(&c->journal.lock); + + mask = c->journal.pin.mask; + nr = 0; + atomic_long_inc(&c->flush_write); + memset(btree_nodes, 0, sizeof(btree_nodes)); + + mutex_lock(&c->bucket_lock); + list_for_each_entry_safe_reverse(b, t, &c->btree_cache, list) { + /* + * It is safe to get now_fifo_front_p without holding + * c->journal.lock here, because we don't need to know + * the exactly accurate value, just check whether the + * front pointer of c->journal.pin is changed. + */ + now_fifo_front_p = &fifo_front(&c->journal.pin); + /* + * If the oldest journal entry is reclaimed and front + * pointer of c->journal.pin changes, it is unnecessary + * to scan c->btree_cache anymore, just quit the loop and + * flush out what we have already. + */ + if (now_fifo_front_p != fifo_front_p) + break; + /* + * quit this loop if all matching btree nodes are + * scanned and record in btree_nodes[] already. + */ + ref_nr = atomic_read(fifo_front_p); + if (nr >= ref_nr) + break; + + if (btree_node_journal_flush(b)) + pr_err("BUG: flush_write bit should not be set here!\n"); + + mutex_lock(&b->write_lock); + + if (!btree_node_dirty(b)) { + mutex_unlock(&b->write_lock); + continue; + } + + if (!btree_current_write(b)->journal) { + mutex_unlock(&b->write_lock); + continue; + } + + /* + * Only select the btree node which exactly references + * the oldest journal entry. + * + * If the journal entry pointed by fifo_front_p is + * reclaimed in parallel, don't worry: + * - the list_for_each_xxx loop will quit when checking + * next now_fifo_front_p. + * - If there are matched nodes recorded in btree_nodes[], + * they are clean now (this is why and how the oldest + * journal entry can be reclaimed). These selected nodes + * will be ignored and skipped in the following for-loop. + */ + if (((btree_current_write(b)->journal - fifo_front_p) & + mask) != 0) { + mutex_unlock(&b->write_lock); + continue; + } + + set_btree_node_journal_flush(b); + + mutex_unlock(&b->write_lock); + + btree_nodes[nr++] = b; + /* + * To avoid holding c->bucket_lock too long time, + * only scan for BTREE_FLUSH_NR matched btree nodes + * at most. If there are more btree nodes reference + * the oldest journal entry, try to flush them next + * time when btree_flush_write() is called. + */ + if (nr == BTREE_FLUSH_NR) + break; + } + mutex_unlock(&c->bucket_lock); + + for (i = 0; i < nr; i++) { + b = btree_nodes[i]; + if (!b) { + pr_err("BUG: btree_nodes[%d] is NULL\n", i); + continue; + } + + /* safe to check without holding b->write_lock */ + if (!btree_node_journal_flush(b)) { + pr_err("BUG: bnode %p: journal_flush bit cleaned\n", b); + continue; + } + + mutex_lock(&b->write_lock); + if (!btree_current_write(b)->journal) { + clear_bit(BTREE_NODE_journal_flush, &b->flags); + mutex_unlock(&b->write_lock); + pr_debug("bnode %p: written by others\n", b); + continue; + } + + if (!btree_node_dirty(b)) { + clear_bit(BTREE_NODE_journal_flush, &b->flags); + mutex_unlock(&b->write_lock); + pr_debug("bnode %p: dirty bit cleaned by others\n", b); + continue; + } + + __bch_btree_node_write(b, NULL); + clear_bit(BTREE_NODE_journal_flush, &b->flags); + mutex_unlock(&b->write_lock); + } + +out: + spin_lock(&c->journal.flush_write_lock); + c->journal.btree_flushing = false; + spin_unlock(&c->journal.flush_write_lock); +} + +#define last_seq(j) ((j)->seq - fifo_used(&(j)->pin) + 1) + +static void journal_discard_endio(struct bio *bio) +{ + struct journal_device *ja = + container_of(bio, struct journal_device, discard_bio); + struct cache *ca = container_of(ja, struct cache, journal); + + atomic_set(&ja->discard_in_flight, DISCARD_DONE); + + closure_wake_up(&ca->set->journal.wait); + closure_put(&ca->set->cl); +} + +static void journal_discard_work(struct work_struct *work) +{ + struct journal_device *ja = + container_of(work, struct journal_device, discard_work); + + submit_bio(&ja->discard_bio); +} + +static void do_journal_discard(struct cache *ca) +{ + struct journal_device *ja = &ca->journal; + struct bio *bio = &ja->discard_bio; + + if (!ca->discard) { + ja->discard_idx = ja->last_idx; + return; + } + + switch (atomic_read(&ja->discard_in_flight)) { + case DISCARD_IN_FLIGHT: + return; + + case DISCARD_DONE: + ja->discard_idx = (ja->discard_idx + 1) % + ca->sb.njournal_buckets; + + atomic_set(&ja->discard_in_flight, DISCARD_READY); + fallthrough; + + case DISCARD_READY: + if (ja->discard_idx == ja->last_idx) + return; + + atomic_set(&ja->discard_in_flight, DISCARD_IN_FLIGHT); + + bio_init(bio, ca->bdev, bio->bi_inline_vecs, 1, REQ_OP_DISCARD); + bio->bi_iter.bi_sector = bucket_to_sector(ca->set, + ca->sb.d[ja->discard_idx]); + bio->bi_iter.bi_size = bucket_bytes(ca); + bio->bi_end_io = journal_discard_endio; + + closure_get(&ca->set->cl); + INIT_WORK(&ja->discard_work, journal_discard_work); + queue_work(bch_journal_wq, &ja->discard_work); + } +} + +static unsigned int free_journal_buckets(struct cache_set *c) +{ + struct journal *j = &c->journal; + struct cache *ca = c->cache; + struct journal_device *ja = &c->cache->journal; + unsigned int n; + + /* In case njournal_buckets is not power of 2 */ + if (ja->cur_idx >= ja->discard_idx) + n = ca->sb.njournal_buckets + ja->discard_idx - ja->cur_idx; + else + n = ja->discard_idx - ja->cur_idx; + + if (n > (1 + j->do_reserve)) + return n - (1 + j->do_reserve); + + return 0; +} + +static void journal_reclaim(struct cache_set *c) +{ + struct bkey *k = &c->journal.key; + struct cache *ca = c->cache; + uint64_t last_seq; + struct journal_device *ja = &ca->journal; + atomic_t p __maybe_unused; + + atomic_long_inc(&c->reclaim); + + while (!atomic_read(&fifo_front(&c->journal.pin))) + fifo_pop(&c->journal.pin, p); + + last_seq = last_seq(&c->journal); + + /* Update last_idx */ + + while (ja->last_idx != ja->cur_idx && + ja->seq[ja->last_idx] < last_seq) + ja->last_idx = (ja->last_idx + 1) % + ca->sb.njournal_buckets; + + do_journal_discard(ca); + + if (c->journal.blocks_free) + goto out; + + if (!free_journal_buckets(c)) + goto out; + + ja->cur_idx = (ja->cur_idx + 1) % ca->sb.njournal_buckets; + k->ptr[0] = MAKE_PTR(0, + bucket_to_sector(c, ca->sb.d[ja->cur_idx]), + ca->sb.nr_this_dev); + atomic_long_inc(&c->reclaimed_journal_buckets); + + bkey_init(k); + SET_KEY_PTRS(k, 1); + c->journal.blocks_free = ca->sb.bucket_size >> c->block_bits; + +out: + if (!journal_full(&c->journal)) + __closure_wake_up(&c->journal.wait); +} + +void bch_journal_next(struct journal *j) +{ + atomic_t p = { 1 }; + + j->cur = (j->cur == j->w) + ? &j->w[1] + : &j->w[0]; + + /* + * The fifo_push() needs to happen at the same time as j->seq is + * incremented for last_seq() to be calculated correctly + */ + BUG_ON(!fifo_push(&j->pin, p)); + atomic_set(&fifo_back(&j->pin), 1); + + j->cur->data->seq = ++j->seq; + j->cur->dirty = false; + j->cur->need_write = false; + j->cur->data->keys = 0; + + if (fifo_full(&j->pin)) + pr_debug("journal_pin full (%zu)\n", fifo_used(&j->pin)); +} + +static void journal_write_endio(struct bio *bio) +{ + struct journal_write *w = bio->bi_private; + + cache_set_err_on(bio->bi_status, w->c, "journal io error"); + closure_put(&w->c->journal.io); +} + +static void journal_write(struct closure *cl); + +static void journal_write_done(struct closure *cl) +{ + struct journal *j = container_of(cl, struct journal, io); + struct journal_write *w = (j->cur == j->w) + ? &j->w[1] + : &j->w[0]; + + __closure_wake_up(&w->wait); + continue_at_nobarrier(cl, journal_write, bch_journal_wq); +} + +static void journal_write_unlock(struct closure *cl) + __releases(&c->journal.lock) +{ + struct cache_set *c = container_of(cl, struct cache_set, journal.io); + + c->journal.io_in_flight = 0; + spin_unlock(&c->journal.lock); +} + +static void journal_write_unlocked(struct closure *cl) + __releases(c->journal.lock) +{ + struct cache_set *c = container_of(cl, struct cache_set, journal.io); + struct cache *ca = c->cache; + struct journal_write *w = c->journal.cur; + struct bkey *k = &c->journal.key; + unsigned int i, sectors = set_blocks(w->data, block_bytes(ca)) * + ca->sb.block_size; + + struct bio *bio; + struct bio_list list; + + bio_list_init(&list); + + if (!w->need_write) { + closure_return_with_destructor(cl, journal_write_unlock); + return; + } else if (journal_full(&c->journal)) { + journal_reclaim(c); + spin_unlock(&c->journal.lock); + + btree_flush_write(c); + continue_at(cl, journal_write, bch_journal_wq); + return; + } + + c->journal.blocks_free -= set_blocks(w->data, block_bytes(ca)); + + w->data->btree_level = c->root->level; + + bkey_copy(&w->data->btree_root, &c->root->key); + bkey_copy(&w->data->uuid_bucket, &c->uuid_bucket); + + w->data->prio_bucket[ca->sb.nr_this_dev] = ca->prio_buckets[0]; + w->data->magic = jset_magic(&ca->sb); + w->data->version = BCACHE_JSET_VERSION; + w->data->last_seq = last_seq(&c->journal); + w->data->csum = csum_set(w->data); + + for (i = 0; i < KEY_PTRS(k); i++) { + ca = c->cache; + bio = &ca->journal.bio; + + atomic_long_add(sectors, &ca->meta_sectors_written); + + bio_reset(bio, ca->bdev, REQ_OP_WRITE | + REQ_SYNC | REQ_META | REQ_PREFLUSH | REQ_FUA); + bio->bi_iter.bi_sector = PTR_OFFSET(k, i); + bio->bi_iter.bi_size = sectors << 9; + + bio->bi_end_io = journal_write_endio; + bio->bi_private = w; + bch_bio_map(bio, w->data); + + trace_bcache_journal_write(bio, w->data->keys); + bio_list_add(&list, bio); + + SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + sectors); + + ca->journal.seq[ca->journal.cur_idx] = w->data->seq; + } + + /* If KEY_PTRS(k) == 0, this jset gets lost in air */ + BUG_ON(i == 0); + + atomic_dec_bug(&fifo_back(&c->journal.pin)); + bch_journal_next(&c->journal); + journal_reclaim(c); + + spin_unlock(&c->journal.lock); + + while ((bio = bio_list_pop(&list))) + closure_bio_submit(c, bio, cl); + + continue_at(cl, journal_write_done, NULL); +} + +static void journal_write(struct closure *cl) +{ + struct cache_set *c = container_of(cl, struct cache_set, journal.io); + + spin_lock(&c->journal.lock); + journal_write_unlocked(cl); +} + +static void journal_try_write(struct cache_set *c) + __releases(c->journal.lock) +{ + struct closure *cl = &c->journal.io; + struct journal_write *w = c->journal.cur; + + w->need_write = true; + + if (!c->journal.io_in_flight) { + c->journal.io_in_flight = 1; + closure_call(cl, journal_write_unlocked, NULL, &c->cl); + } else { + spin_unlock(&c->journal.lock); + } +} + +static struct journal_write *journal_wait_for_write(struct cache_set *c, + unsigned int nkeys) + __acquires(&c->journal.lock) +{ + size_t sectors; + struct closure cl; + bool wait = false; + struct cache *ca = c->cache; + + closure_init_stack(&cl); + + spin_lock(&c->journal.lock); + + while (1) { + struct journal_write *w = c->journal.cur; + + sectors = __set_blocks(w->data, w->data->keys + nkeys, + block_bytes(ca)) * ca->sb.block_size; + + if (sectors <= min_t(size_t, + c->journal.blocks_free * ca->sb.block_size, + PAGE_SECTORS << JSET_BITS)) + return w; + + if (wait) + closure_wait(&c->journal.wait, &cl); + + if (!journal_full(&c->journal)) { + if (wait) + trace_bcache_journal_entry_full(c); + + /* + * XXX: If we were inserting so many keys that they + * won't fit in an _empty_ journal write, we'll + * deadlock. For now, handle this in + * bch_keylist_realloc() - but something to think about. + */ + BUG_ON(!w->data->keys); + + journal_try_write(c); /* unlocks */ + } else { + if (wait) + trace_bcache_journal_full(c); + + journal_reclaim(c); + spin_unlock(&c->journal.lock); + + btree_flush_write(c); + } + + closure_sync(&cl); + spin_lock(&c->journal.lock); + wait = true; + } +} + +static void journal_write_work(struct work_struct *work) +{ + struct cache_set *c = container_of(to_delayed_work(work), + struct cache_set, + journal.work); + spin_lock(&c->journal.lock); + if (c->journal.cur->dirty) + journal_try_write(c); + else + spin_unlock(&c->journal.lock); +} + +/* + * Entry point to the journalling code - bio_insert() and btree_invalidate() + * pass bch_journal() a list of keys to be journalled, and then + * bch_journal() hands those same keys off to btree_insert_async() + */ + +atomic_t *bch_journal(struct cache_set *c, + struct keylist *keys, + struct closure *parent) +{ + struct journal_write *w; + atomic_t *ret; + + /* No journaling if CACHE_SET_IO_DISABLE set already */ + if (unlikely(test_bit(CACHE_SET_IO_DISABLE, &c->flags))) + return NULL; + + if (!CACHE_SYNC(&c->cache->sb)) + return NULL; + + w = journal_wait_for_write(c, bch_keylist_nkeys(keys)); + + memcpy(bset_bkey_last(w->data), keys->keys, bch_keylist_bytes(keys)); + w->data->keys += bch_keylist_nkeys(keys); + + ret = &fifo_back(&c->journal.pin); + atomic_inc(ret); + + if (parent) { + closure_wait(&w->wait, parent); + journal_try_write(c); + } else if (!w->dirty) { + w->dirty = true; + queue_delayed_work(bch_flush_wq, &c->journal.work, + msecs_to_jiffies(c->journal_delay_ms)); + spin_unlock(&c->journal.lock); + } else { + spin_unlock(&c->journal.lock); + } + + + return ret; +} + +void bch_journal_meta(struct cache_set *c, struct closure *cl) +{ + struct keylist keys; + atomic_t *ref; + + bch_keylist_init(&keys); + + ref = bch_journal(c, &keys, cl); + if (ref) + atomic_dec_bug(ref); +} + +void bch_journal_free(struct cache_set *c) +{ + free_pages((unsigned long) c->journal.w[1].data, JSET_BITS); + free_pages((unsigned long) c->journal.w[0].data, JSET_BITS); + free_fifo(&c->journal.pin); +} + +int bch_journal_alloc(struct cache_set *c) +{ + struct journal *j = &c->journal; + + spin_lock_init(&j->lock); + spin_lock_init(&j->flush_write_lock); + INIT_DELAYED_WORK(&j->work, journal_write_work); + + c->journal_delay_ms = 100; + + j->w[0].c = c; + j->w[1].c = c; + + if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) || + !(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP, JSET_BITS)) || + !(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP, JSET_BITS))) + return -ENOMEM; + + return 0; +} |