bcachefs: Discard, invalidate workers are now per device

There's no reason for discards to be single threaded across all devices;
this will improve performance on multi device setups.

Additionally, making them per-device simplifies the refcounting on
bch_dev->io_ref; we now hold it for the duration that the discard path
is running, which fixes a race between the discard path and device
removal.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2024-06-23 00:53:44 -04:00
parent 472237b69d
commit 64ee1431cc
5 changed files with 161 additions and 133 deletions

View File

@ -29,7 +29,7 @@
#include <linux/sched/task.h>
#include <linux/sort.h>
static void bch2_discard_one_bucket_fast(struct bch_fs *c, struct bpos bucket);
static void bch2_discard_one_bucket_fast(struct bch_dev *, u64);
/* Persistent alloc info: */
@ -893,12 +893,12 @@ int bch2_trigger_alloc(struct btree_trans *trans,
if (statechange(a->data_type == BCH_DATA_need_discard) &&
!bch2_bucket_is_open_safe(c, new.k->p.inode, new.k->p.offset) &&
bucket_flushed(new_a))
bch2_discard_one_bucket_fast(c, new.k->p);
bch2_discard_one_bucket_fast(ca, new.k->p.offset);
if (statechange(a->data_type == BCH_DATA_cached) &&
!bch2_bucket_is_open(c, new.k->p.inode, new.k->p.offset) &&
should_invalidate_buckets(ca, bch2_dev_usage_read(ca)))
bch2_do_invalidates(c);
bch2_dev_do_invalidates(ca);
if (statechange(a->data_type == BCH_DATA_need_gc_gens))
bch2_gc_gens_async(c);
@ -1636,34 +1636,38 @@ int bch2_check_alloc_to_lru_refs(struct bch_fs *c)
return ret;
}
static int discard_in_flight_add(struct bch_fs *c, struct bpos bucket)
static int discard_in_flight_add(struct bch_dev *ca, u64 bucket, bool in_progress)
{
int ret;
mutex_lock(&c->discard_buckets_in_flight_lock);
darray_for_each(c->discard_buckets_in_flight, i)
if (bkey_eq(*i, bucket)) {
mutex_lock(&ca->discard_buckets_in_flight_lock);
darray_for_each(ca->discard_buckets_in_flight, i)
if (i->bucket == bucket) {
ret = -BCH_ERR_EEXIST_discard_in_flight_add;
goto out;
}
ret = darray_push(&c->discard_buckets_in_flight, bucket);
ret = darray_push(&ca->discard_buckets_in_flight, ((struct discard_in_flight) {
.in_progress = in_progress,
.bucket = bucket,
}));
out:
mutex_unlock(&c->discard_buckets_in_flight_lock);
mutex_unlock(&ca->discard_buckets_in_flight_lock);
return ret;
}
static void discard_in_flight_remove(struct bch_fs *c, struct bpos bucket)
static void discard_in_flight_remove(struct bch_dev *ca, u64 bucket)
{
mutex_lock(&c->discard_buckets_in_flight_lock);
darray_for_each(c->discard_buckets_in_flight, i)
if (bkey_eq(*i, bucket)) {
darray_remove_item(&c->discard_buckets_in_flight, i);
mutex_lock(&ca->discard_buckets_in_flight_lock);
darray_for_each(ca->discard_buckets_in_flight, i)
if (i->bucket == bucket) {
BUG_ON(!i->in_progress);
darray_remove_item(&ca->discard_buckets_in_flight, i);
goto found;
}
BUG();
found:
mutex_unlock(&c->discard_buckets_in_flight_lock);
mutex_unlock(&ca->discard_buckets_in_flight_lock);
}
struct discard_buckets_state {
@ -1671,26 +1675,11 @@ struct discard_buckets_state {
u64 open;
u64 need_journal_commit;
u64 discarded;
struct bch_dev *ca;
u64 need_journal_commit_this_dev;
};
static void discard_buckets_next_dev(struct bch_fs *c, struct discard_buckets_state *s, struct bch_dev *ca)
{
if (s->ca == ca)
return;
if (s->ca && s->need_journal_commit_this_dev >
bch2_dev_usage_read(s->ca).d[BCH_DATA_free].buckets)
bch2_journal_flush_async(&c->journal, NULL);
if (s->ca)
percpu_ref_put(&s->ca->io_ref);
s->ca = ca;
s->need_journal_commit_this_dev = 0;
}
static int bch2_discard_one_bucket(struct btree_trans *trans,
struct bch_dev *ca,
struct btree_iter *need_discard_iter,
struct bpos *discard_pos_done,
struct discard_buckets_state *s)
@ -1704,16 +1693,6 @@ static int bch2_discard_one_bucket(struct btree_trans *trans,
bool discard_locked = false;
int ret = 0;
struct bch_dev *ca = s->ca && s->ca->dev_idx == pos.inode
? s->ca
: bch2_dev_get_ioref(c, pos.inode, WRITE);
if (!ca) {
bch2_btree_iter_set_pos(need_discard_iter, POS(pos.inode + 1, 0));
return 0;
}
discard_buckets_next_dev(c, s, ca);
if (bch2_bucket_is_open_safe(c, pos.inode, pos.offset)) {
s->open++;
goto out;
@ -1773,7 +1752,7 @@ static int bch2_discard_one_bucket(struct btree_trans *trans,
goto out;
}
if (discard_in_flight_add(c, SPOS(iter.pos.inode, iter.pos.offset, true)))
if (discard_in_flight_add(ca, iter.pos.offset, true))
goto out;
discard_locked = true;
@ -1811,7 +1790,7 @@ write:
s->discarded++;
out:
if (discard_locked)
discard_in_flight_remove(c, iter.pos);
discard_in_flight_remove(ca, iter.pos.offset);
s->seen++;
bch2_trans_iter_exit(trans, &iter);
printbuf_exit(&buf);
@ -1820,7 +1799,8 @@ out:
static void bch2_do_discards_work(struct work_struct *work)
{
struct bch_fs *c = container_of(work, struct bch_fs, discard_work);
struct bch_dev *ca = container_of(work, struct bch_dev, discard_work);
struct bch_fs *c = ca->fs;
struct discard_buckets_state s = {};
struct bpos discard_pos_done = POS_MAX;
int ret;
@ -1831,23 +1811,41 @@ static void bch2_do_discards_work(struct work_struct *work)
* successful commit:
*/
ret = bch2_trans_run(c,
for_each_btree_key(trans, iter,
BTREE_ID_need_discard, POS_MIN, 0, k,
bch2_discard_one_bucket(trans, &iter, &discard_pos_done, &s)));
discard_buckets_next_dev(c, &s, NULL);
for_each_btree_key_upto(trans, iter,
BTREE_ID_need_discard,
POS(ca->dev_idx, 0),
POS(ca->dev_idx, U64_MAX), 0, k,
bch2_discard_one_bucket(trans, ca, &iter, &discard_pos_done, &s)));
trace_discard_buckets(c, s.seen, s.open, s.need_journal_commit, s.discarded,
bch2_err_str(ret));
bch2_write_ref_put(c, BCH_WRITE_REF_discard);
percpu_ref_put(&ca->io_ref);
}
void bch2_dev_do_discards(struct bch_dev *ca)
{
struct bch_fs *c = ca->fs;
if (!bch2_dev_get_ioref(c, ca->dev_idx, WRITE))
return;
if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_discard))
goto put_ioref;
if (queue_work(c->write_ref_wq, &ca->discard_work))
return;
bch2_write_ref_put(c, BCH_WRITE_REF_discard);
put_ioref:
percpu_ref_put(&ca->io_ref);
}
void bch2_do_discards(struct bch_fs *c)
{
if (bch2_write_ref_tryget(c, BCH_WRITE_REF_discard) &&
!queue_work(c->write_ref_wq, &c->discard_work))
bch2_write_ref_put(c, BCH_WRITE_REF_discard);
for_each_member_device(c, ca)
bch2_dev_do_discards(ca);
}
static int bch2_clear_bucket_needs_discard(struct btree_trans *trans, struct bpos bucket)
@ -1876,68 +1874,69 @@ err:
static void bch2_do_discards_fast_work(struct work_struct *work)
{
struct bch_fs *c = container_of(work, struct bch_fs, discard_fast_work);
struct bch_dev *ca = container_of(work, struct bch_dev, discard_fast_work);
struct bch_fs *c = ca->fs;
while (1) {
bool got_bucket = false;
struct bpos bucket;
struct bch_dev *ca;
u64 bucket;
mutex_lock(&c->discard_buckets_in_flight_lock);
darray_for_each(c->discard_buckets_in_flight, i) {
if (i->snapshot)
mutex_lock(&ca->discard_buckets_in_flight_lock);
darray_for_each(ca->discard_buckets_in_flight, i) {
if (i->in_progress)
continue;
ca = bch2_dev_get_ioref(c, i->inode, WRITE);
if (!ca) {
darray_remove_item(&c->discard_buckets_in_flight, i);
continue;
}
got_bucket = true;
bucket = *i;
i->snapshot = true;
bucket = i->bucket;
i->in_progress = true;
break;
}
mutex_unlock(&c->discard_buckets_in_flight_lock);
mutex_unlock(&ca->discard_buckets_in_flight_lock);
if (!got_bucket)
break;
if (ca->mi.discard && !c->opts.nochanges)
blkdev_issue_discard(ca->disk_sb.bdev,
bucket.offset * ca->mi.bucket_size,
bucket_to_sector(ca, bucket),
ca->mi.bucket_size,
GFP_KERNEL);
int ret = bch2_trans_do(c, NULL, NULL,
BCH_WATERMARK_btree|
BCH_TRANS_COMMIT_no_enospc,
bch2_clear_bucket_needs_discard(trans, bucket));
BCH_WATERMARK_btree|
BCH_TRANS_COMMIT_no_enospc,
bch2_clear_bucket_needs_discard(trans, POS(ca->dev_idx, bucket)));
bch_err_fn(c, ret);
percpu_ref_put(&ca->io_ref);
discard_in_flight_remove(c, bucket);
discard_in_flight_remove(ca, bucket);
if (ret)
break;
}
bch2_write_ref_put(c, BCH_WRITE_REF_discard_fast);
percpu_ref_put(&ca->io_ref);
}
static void bch2_discard_one_bucket_fast(struct bch_fs *c, struct bpos bucket)
static void bch2_discard_one_bucket_fast(struct bch_dev *ca, u64 bucket)
{
rcu_read_lock();
struct bch_dev *ca = bch2_dev_rcu(c, bucket.inode);
bool dead = !ca || percpu_ref_is_dying(&ca->io_ref);
rcu_read_unlock();
struct bch_fs *c = ca->fs;
if (!dead &&
!discard_in_flight_add(c, bucket) &&
bch2_write_ref_tryget(c, BCH_WRITE_REF_discard_fast) &&
!queue_work(c->write_ref_wq, &c->discard_fast_work))
bch2_write_ref_put(c, BCH_WRITE_REF_discard_fast);
if (discard_in_flight_add(ca, bucket, false))
return;
if (!bch2_dev_get_ioref(c, ca->dev_idx, WRITE))
return;
if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_discard_fast))
goto put_ioref;
if (queue_work(c->write_ref_wq, &ca->discard_fast_work))
return;
bch2_write_ref_put(c, BCH_WRITE_REF_discard_fast);
put_ioref:
percpu_ref_put(&ca->io_ref);
}
static int invalidate_one_bucket(struct btree_trans *trans,
@ -2038,7 +2037,8 @@ again:
static void bch2_do_invalidates_work(struct work_struct *work)
{
struct bch_fs *c = container_of(work, struct bch_fs, invalidate_work);
struct bch_dev *ca = container_of(work, struct bch_dev, invalidate_work);
struct bch_fs *c = ca->fs;
struct btree_trans *trans = bch2_trans_get(c);
int ret = 0;
@ -2046,52 +2046,63 @@ static void bch2_do_invalidates_work(struct work_struct *work)
if (ret)
goto err;
for_each_member_device(c, ca) {
s64 nr_to_invalidate =
should_invalidate_buckets(ca, bch2_dev_usage_read(ca));
struct btree_iter iter;
bool wrapped = false;
s64 nr_to_invalidate =
should_invalidate_buckets(ca, bch2_dev_usage_read(ca));
struct btree_iter iter;
bool wrapped = false;
bch2_trans_iter_init(trans, &iter, BTREE_ID_lru,
lru_pos(ca->dev_idx, 0,
((bch2_current_io_time(c, READ) + U32_MAX) &
LRU_TIME_MAX)), 0);
bch2_trans_iter_init(trans, &iter, BTREE_ID_lru,
lru_pos(ca->dev_idx, 0,
((bch2_current_io_time(c, READ) + U32_MAX) &
LRU_TIME_MAX)), 0);
while (true) {
bch2_trans_begin(trans);
while (true) {
bch2_trans_begin(trans);
struct bkey_s_c k = next_lru_key(trans, &iter, ca, &wrapped);
ret = bkey_err(k);
if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
continue;
if (ret)
break;
if (!k.k)
break;
ret = invalidate_one_bucket(trans, &iter, k, &nr_to_invalidate);
if (ret)
break;
bch2_btree_iter_advance(&iter);
}
bch2_trans_iter_exit(trans, &iter);
if (ret < 0) {
bch2_dev_put(ca);
struct bkey_s_c k = next_lru_key(trans, &iter, ca, &wrapped);
ret = bkey_err(k);
if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
continue;
if (ret)
break;
}
if (!k.k)
break;
ret = invalidate_one_bucket(trans, &iter, k, &nr_to_invalidate);
if (ret)
break;
bch2_btree_iter_advance(&iter);
}
bch2_trans_iter_exit(trans, &iter);
err:
bch2_trans_put(trans);
bch2_write_ref_put(c, BCH_WRITE_REF_invalidate);
percpu_ref_put(&ca->io_ref);
}
void bch2_dev_do_invalidates(struct bch_dev *ca)
{
struct bch_fs *c = ca->fs;
if (!bch2_dev_get_ioref(c, ca->dev_idx, WRITE))
return;
if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_invalidate))
goto put_ioref;
if (queue_work(c->write_ref_wq, &ca->invalidate_work))
return;
bch2_write_ref_put(c, BCH_WRITE_REF_invalidate);
put_ioref:
percpu_ref_put(&ca->io_ref);
}
void bch2_do_invalidates(struct bch_fs *c)
{
if (bch2_write_ref_tryget(c, BCH_WRITE_REF_invalidate) &&
!queue_work(c->write_ref_wq, &c->invalidate_work))
bch2_write_ref_put(c, BCH_WRITE_REF_invalidate);
for_each_member_device(c, ca)
bch2_dev_do_invalidates(ca);
}
int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
@ -2407,16 +2418,20 @@ void bch2_dev_allocator_add(struct bch_fs *c, struct bch_dev *ca)
set_bit(ca->dev_idx, c->rw_devs[i].d);
}
void bch2_fs_allocator_background_exit(struct bch_fs *c)
void bch2_dev_allocator_background_exit(struct bch_dev *ca)
{
darray_exit(&c->discard_buckets_in_flight);
darray_exit(&ca->discard_buckets_in_flight);
}
void bch2_dev_allocator_background_init(struct bch_dev *ca)
{
mutex_init(&ca->discard_buckets_in_flight_lock);
INIT_WORK(&ca->discard_work, bch2_do_discards_work);
INIT_WORK(&ca->discard_fast_work, bch2_do_discards_fast_work);
INIT_WORK(&ca->invalidate_work, bch2_do_invalidates_work);
}
void bch2_fs_allocator_background_init(struct bch_fs *c)
{
spin_lock_init(&c->freelist_lock);
mutex_init(&c->discard_buckets_in_flight_lock);
INIT_WORK(&c->discard_work, bch2_do_discards_work);
INIT_WORK(&c->discard_fast_work, bch2_do_discards_fast_work);
INIT_WORK(&c->invalidate_work, bch2_do_invalidates_work);
}

View File

@ -275,6 +275,7 @@ int bch2_trigger_alloc(struct btree_trans *, enum btree_id, unsigned,
enum btree_iter_update_trigger_flags);
int bch2_check_alloc_info(struct bch_fs *);
int bch2_check_alloc_to_lru_refs(struct bch_fs *);
void bch2_dev_do_discards(struct bch_dev *);
void bch2_do_discards(struct bch_fs *);
static inline u64 should_invalidate_buckets(struct bch_dev *ca,
@ -289,6 +290,7 @@ static inline u64 should_invalidate_buckets(struct bch_dev *ca,
return clamp_t(s64, want_free - free, 0, u.d[BCH_DATA_cached].buckets);
}
void bch2_dev_do_invalidates(struct bch_dev *);
void bch2_do_invalidates(struct bch_fs *);
static inline struct bch_backpointer *alloc_v4_backpointers(struct bch_alloc_v4 *a)
@ -312,7 +314,9 @@ u64 bch2_min_rw_member_capacity(struct bch_fs *);
void bch2_dev_allocator_remove(struct bch_fs *, struct bch_dev *);
void bch2_dev_allocator_add(struct bch_fs *, struct bch_dev *);
void bch2_fs_allocator_background_exit(struct bch_fs *);
void bch2_dev_allocator_background_exit(struct bch_dev *);
void bch2_dev_allocator_background_init(struct bch_dev *);
void bch2_fs_allocator_background_init(struct bch_fs *);
#endif /* _BCACHEFS_ALLOC_BACKGROUND_H */

View File

@ -621,13 +621,13 @@ again:
avail = dev_buckets_free(ca, *usage, watermark);
if (usage->d[BCH_DATA_need_discard].buckets > avail)
bch2_do_discards(c);
bch2_dev_do_discards(ca);
if (usage->d[BCH_DATA_need_gc_gens].buckets > avail)
bch2_gc_gens_async(c);
if (should_invalidate_buckets(ca, *usage))
bch2_do_invalidates(c);
bch2_dev_do_invalidates(ca);
if (!avail) {
if (cl && !waiting) {

View File

@ -493,6 +493,11 @@ struct io_count {
u64 sectors[2][BCH_DATA_NR];
};
struct discard_in_flight {
bool in_progress:1;
u64 bucket:63;
};
struct bch_dev {
struct kobject kobj;
#ifdef CONFIG_BCACHEFS_DEBUG
@ -554,6 +559,12 @@ struct bch_dev {
size_t inc_gen_really_needs_gc;
size_t buckets_waiting_on_journal;
struct work_struct invalidate_work;
struct work_struct discard_work;
struct mutex discard_buckets_in_flight_lock;
DARRAY(struct discard_in_flight) discard_buckets_in_flight;
struct work_struct discard_fast_work;
atomic64_t rebalance_work;
struct journal_device journal;
@ -915,11 +926,6 @@ struct bch_fs {
unsigned write_points_nr;
struct buckets_waiting_for_journal buckets_waiting_for_journal;
struct work_struct invalidate_work;
struct work_struct discard_work;
struct mutex discard_buckets_in_flight_lock;
DARRAY(struct bpos) discard_buckets_in_flight;
struct work_struct discard_fast_work;
/* GARBAGE COLLECTION */
struct work_struct gc_gens_work;

View File

@ -536,7 +536,6 @@ static void __bch2_fs_free(struct bch_fs *c)
bch2_find_btree_nodes_exit(&c->found_btree_nodes);
bch2_free_pending_node_rewrites(c);
bch2_fs_allocator_background_exit(c);
bch2_fs_sb_errors_exit(c);
bch2_fs_counters_exit(c);
bch2_fs_snapshots_exit(c);
@ -1195,6 +1194,7 @@ static void bch2_dev_free(struct bch_dev *ca)
kfree(ca->buckets_nouse);
bch2_free_super(&ca->disk_sb);
bch2_dev_allocator_background_exit(ca);
bch2_dev_journal_exit(ca);
free_percpu(ca->io_done);
@ -1317,6 +1317,8 @@ static struct bch_dev *__bch2_dev_alloc(struct bch_fs *c,
atomic_long_set(&ca->ref, 1);
#endif
bch2_dev_allocator_background_init(ca);
if (percpu_ref_init(&ca->io_ref, bch2_dev_io_ref_complete,
PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
!(ca->sb_read_scratch = (void *) __get_free_page(GFP_KERNEL)) ||
@ -1541,6 +1543,7 @@ static void __bch2_dev_read_write(struct bch_fs *c, struct bch_dev *ca)
bch2_dev_allocator_add(c, ca);
bch2_recalc_capacity(c);
bch2_dev_do_discards(ca);
}
int __bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,