#include "debug.h"
#include "writeback.h"
+#include <linux/delay.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
#include <trace/events/bcache.h>
-static struct workqueue_struct *dirty_wq;
-
-static void read_dirty(struct closure *);
-
-struct dirty_io {
- struct closure cl;
- struct cached_dev *dc;
- struct bio bio;
-};
-
/* Rate limiting */
static void __update_writeback_rate(struct cached_dev *dc)
dc->writeback_rate_derivative = derivative;
dc->writeback_rate_change = change;
dc->writeback_rate_target = target;
-
- schedule_delayed_work(&dc->writeback_rate_update,
- dc->writeback_rate_update_seconds * HZ);
}
static void update_writeback_rate(struct work_struct *work)
__update_writeback_rate(dc);
up_read(&dc->writeback_lock);
+
+ schedule_delayed_work(&dc->writeback_rate_update,
+ dc->writeback_rate_update_seconds * HZ);
}
static unsigned writeback_delay(struct cached_dev *dc, unsigned sectors)
{
uint64_t ret;
- if (atomic_read(&dc->disk.detaching) ||
+ if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
!dc->writeback_percent)
return 0;
return min_t(uint64_t, ret, HZ);
}
-/* Background writeback */
-
-static bool dirty_pred(struct keybuf *buf, struct bkey *k)
-{
- return KEY_DIRTY(k);
-}
-
-static bool dirty_full_stripe_pred(struct keybuf *buf, struct bkey *k)
-{
- uint64_t stripe;
- unsigned nr_sectors = KEY_SIZE(k);
- struct cached_dev *dc = container_of(buf, struct cached_dev,
- writeback_keys);
- unsigned stripe_size = 1 << dc->disk.stripe_size_bits;
-
- if (!KEY_DIRTY(k))
- return false;
-
- stripe = KEY_START(k) >> dc->disk.stripe_size_bits;
- while (1) {
- if (atomic_read(dc->disk.stripe_sectors_dirty + stripe) !=
- stripe_size)
- return false;
-
- if (nr_sectors <= stripe_size)
- return true;
-
- nr_sectors -= stripe_size;
- stripe++;
- }
-}
+struct dirty_io {
+ struct closure cl;
+ struct cached_dev *dc;
+ struct bio bio;
+};
static void dirty_init(struct keybuf_key *w)
{
if (!io->dc->writeback_percent)
bio_set_prio(bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
- bio->bi_size = KEY_SIZE(&w->key) << 9;
+ bio->bi_iter.bi_size = KEY_SIZE(&w->key) << 9;
bio->bi_max_vecs = DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS);
bio->bi_private = w;
bio->bi_io_vec = bio->bi_inline_vecs;
bch_bio_map(bio, NULL);
}
-static void refill_dirty(struct closure *cl)
-{
- struct cached_dev *dc = container_of(cl, struct cached_dev,
- writeback.cl);
- struct keybuf *buf = &dc->writeback_keys;
- bool searched_from_start = false;
- struct bkey end = MAX_KEY;
- SET_KEY_INODE(&end, dc->disk.id);
-
- if (!atomic_read(&dc->disk.detaching) &&
- !dc->writeback_running)
- closure_return(cl);
-
- down_write(&dc->writeback_lock);
-
- if (!atomic_read(&dc->has_dirty)) {
- SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
- bch_write_bdev_super(dc, NULL);
-
- up_write(&dc->writeback_lock);
- closure_return(cl);
- }
-
- if (bkey_cmp(&buf->last_scanned, &end) >= 0) {
- buf->last_scanned = KEY(dc->disk.id, 0, 0);
- searched_from_start = true;
- }
-
- if (dc->partial_stripes_expensive) {
- uint64_t i;
-
- for (i = 0; i < dc->disk.nr_stripes; i++)
- if (atomic_read(dc->disk.stripe_sectors_dirty + i) ==
- 1 << dc->disk.stripe_size_bits)
- goto full_stripes;
-
- goto normal_refill;
-full_stripes:
- bch_refill_keybuf(dc->disk.c, buf, &end,
- dirty_full_stripe_pred);
- } else {
-normal_refill:
- bch_refill_keybuf(dc->disk.c, buf, &end, dirty_pred);
- }
-
- if (bkey_cmp(&buf->last_scanned, &end) >= 0 && searched_from_start) {
- /* Searched the entire btree - delay awhile */
-
- if (RB_EMPTY_ROOT(&buf->keys)) {
- atomic_set(&dc->has_dirty, 0);
- cached_dev_put(dc);
- }
-
- if (!atomic_read(&dc->disk.detaching))
- closure_delay(&dc->writeback, dc->writeback_delay * HZ);
- }
-
- up_write(&dc->writeback_lock);
-
- bch_ratelimit_reset(&dc->writeback_rate);
-
- /* Punt to workqueue only so we don't recurse and blow the stack */
- continue_at(cl, read_dirty, dirty_wq);
-}
-
-void bch_writeback_queue(struct cached_dev *dc)
-{
- if (closure_trylock(&dc->writeback.cl, &dc->disk.cl)) {
- if (!atomic_read(&dc->disk.detaching))
- closure_delay(&dc->writeback, dc->writeback_delay * HZ);
-
- continue_at(&dc->writeback.cl, refill_dirty, dirty_wq);
- }
-}
-
-void bch_writeback_add(struct cached_dev *dc)
-{
- if (!atomic_read(&dc->has_dirty) &&
- !atomic_xchg(&dc->has_dirty, 1)) {
- atomic_inc(&dc->count);
-
- if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
- SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
- /* XXX: should do this synchronously */
- bch_write_bdev_super(dc, NULL);
- }
-
- bch_writeback_queue(dc);
-
- if (dc->writeback_percent)
- schedule_delayed_work(&dc->writeback_rate_update,
- dc->writeback_rate_update_seconds * HZ);
- }
-}
-
-void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned inode,
- uint64_t offset, int nr_sectors)
-{
- struct bcache_device *d = c->devices[inode];
- unsigned stripe_size, stripe_offset;
- uint64_t stripe;
-
- if (!d)
- return;
-
- stripe_size = 1 << d->stripe_size_bits;
- stripe = offset >> d->stripe_size_bits;
- stripe_offset = offset & (stripe_size - 1);
-
- while (nr_sectors) {
- int s = min_t(unsigned, abs(nr_sectors),
- stripe_size - stripe_offset);
-
- if (nr_sectors < 0)
- s = -s;
-
- atomic_add(s, d->stripe_sectors_dirty + stripe);
- nr_sectors -= s;
- stripe_offset = 0;
- stripe++;
- }
-}
-
-/* Background writeback - IO loop */
-
static void dirty_io_destructor(struct closure *cl)
{
struct dirty_io *io = container_of(cl, struct dirty_io, cl);
/* This is kind of a dumb way of signalling errors. */
if (KEY_DIRTY(&w->key)) {
+ int ret;
unsigned i;
- struct btree_op op;
- bch_btree_op_init_stack(&op);
+ struct keylist keys;
- op.type = BTREE_REPLACE;
- bkey_copy(&op.replace, &w->key);
+ bch_keylist_init(&keys);
- SET_KEY_DIRTY(&w->key, false);
- bch_keylist_add(&op.keys, &w->key);
+ bkey_copy(keys.top, &w->key);
+ SET_KEY_DIRTY(keys.top, false);
+ bch_keylist_push(&keys);
for (i = 0; i < KEY_PTRS(&w->key); i++)
atomic_inc(&PTR_BUCKET(dc->disk.c, &w->key, i)->pin);
- bch_btree_insert(&op, dc->disk.c);
- closure_sync(&op.cl);
+ ret = bch_btree_insert(dc->disk.c, &keys, NULL, &w->key);
- if (op.insert_collision)
+ if (ret)
trace_bcache_writeback_collision(&w->key);
- atomic_long_inc(op.insert_collision
+ atomic_long_inc(ret
? &dc->disk.c->writeback_keys_failed
: &dc->disk.c->writeback_keys_done);
}
dirty_init(w);
io->bio.bi_rw = WRITE;
- io->bio.bi_sector = KEY_START(&w->key);
+ io->bio.bi_iter.bi_sector = KEY_START(&w->key);
io->bio.bi_bdev = io->dc->bdev;
io->bio.bi_end_io = dirty_endio;
continue_at(cl, write_dirty, system_wq);
}
-static void read_dirty(struct closure *cl)
+static void read_dirty(struct cached_dev *dc)
{
- struct cached_dev *dc = container_of(cl, struct cached_dev,
- writeback.cl);
- unsigned delay = writeback_delay(dc, 0);
+ unsigned delay = 0;
struct keybuf_key *w;
struct dirty_io *io;
+ struct closure cl;
+
+ closure_init_stack(&cl);
/*
* XXX: if we error, background writeback just spins. Should use some
* mempools.
*/
- while (1) {
+ while (!kthread_should_stop()) {
+ try_to_freeze();
+
w = bch_keybuf_next(&dc->writeback_keys);
if (!w)
break;
BUG_ON(ptr_stale(dc->disk.c, &w->key, 0));
- if (delay > 0 &&
- (KEY_START(&w->key) != dc->last_read ||
- jiffies_to_msecs(delay) > 50))
- delay = schedule_timeout_uninterruptible(delay);
+ if (KEY_START(&w->key) != dc->last_read ||
+ jiffies_to_msecs(delay) > 50)
+ while (!kthread_should_stop() && delay)
+ delay = schedule_timeout_interruptible(delay);
dc->last_read = KEY_OFFSET(&w->key);
io->dc = dc;
dirty_init(w);
- io->bio.bi_sector = PTR_OFFSET(&w->key, 0);
+ io->bio.bi_iter.bi_sector = PTR_OFFSET(&w->key, 0);
io->bio.bi_bdev = PTR_CACHE(dc->disk.c,
&w->key, 0)->bdev;
io->bio.bi_rw = READ;
trace_bcache_writeback(&w->key);
down(&dc->in_flight);
- closure_call(&io->cl, read_dirty_submit, NULL, cl);
+ closure_call(&io->cl, read_dirty_submit, NULL, &cl);
delay = writeback_delay(dc, KEY_SIZE(&w->key));
}
* Wait for outstanding writeback IOs to finish (and keybuf slots to be
* freed) before refilling again
*/
- continue_at(cl, refill_dirty, dirty_wq);
+ closure_sync(&cl);
}
-/* Init */
+/* Scan for dirty data */
+
+void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned inode,
+ uint64_t offset, int nr_sectors)
+{
+ struct bcache_device *d = c->devices[inode];
+ unsigned stripe_offset, stripe, sectors_dirty;
+
+ if (!d)
+ return;
+
+ stripe = offset_to_stripe(d, offset);
+ stripe_offset = offset & (d->stripe_size - 1);
+
+ while (nr_sectors) {
+ int s = min_t(unsigned, abs(nr_sectors),
+ d->stripe_size - stripe_offset);
+
+ if (nr_sectors < 0)
+ s = -s;
+
+ if (stripe >= d->nr_stripes)
+ return;
+
+ sectors_dirty = atomic_add_return(s,
+ d->stripe_sectors_dirty + stripe);
+ if (sectors_dirty == d->stripe_size)
+ set_bit(stripe, d->full_dirty_stripes);
+ else
+ clear_bit(stripe, d->full_dirty_stripes);
+
+ nr_sectors -= s;
+ stripe_offset = 0;
+ stripe++;
+ }
+}
-static int bch_btree_sectors_dirty_init(struct btree *b, struct btree_op *op,
- struct cached_dev *dc)
+static bool dirty_pred(struct keybuf *buf, struct bkey *k)
{
- struct bkey *k;
- struct btree_iter iter;
-
- bch_btree_iter_init(b, &iter, &KEY(dc->disk.id, 0, 0));
- while ((k = bch_btree_iter_next_filter(&iter, b, bch_ptr_bad)))
- if (!b->level) {
- if (KEY_INODE(k) > dc->disk.id)
- break;
-
- if (KEY_DIRTY(k))
- bcache_dev_sectors_dirty_add(b->c, dc->disk.id,
- KEY_START(k),
- KEY_SIZE(k));
- } else {
- btree(sectors_dirty_init, k, b, op, dc);
- if (KEY_INODE(k) > dc->disk.id)
- break;
-
- cond_resched();
+ return KEY_DIRTY(k);
+}
+
+static void refill_full_stripes(struct cached_dev *dc)
+{
+ struct keybuf *buf = &dc->writeback_keys;
+ unsigned start_stripe, stripe, next_stripe;
+ bool wrapped = false;
+
+ stripe = offset_to_stripe(&dc->disk, KEY_OFFSET(&buf->last_scanned));
+
+ if (stripe >= dc->disk.nr_stripes)
+ stripe = 0;
+
+ start_stripe = stripe;
+
+ while (1) {
+ stripe = find_next_bit(dc->disk.full_dirty_stripes,
+ dc->disk.nr_stripes, stripe);
+
+ if (stripe == dc->disk.nr_stripes)
+ goto next;
+
+ next_stripe = find_next_zero_bit(dc->disk.full_dirty_stripes,
+ dc->disk.nr_stripes, stripe);
+
+ buf->last_scanned = KEY(dc->disk.id,
+ stripe * dc->disk.stripe_size, 0);
+
+ bch_refill_keybuf(dc->disk.c, buf,
+ &KEY(dc->disk.id,
+ next_stripe * dc->disk.stripe_size, 0),
+ dirty_pred);
+
+ if (array_freelist_empty(&buf->freelist))
+ return;
+
+ stripe = next_stripe;
+next:
+ if (wrapped && stripe > start_stripe)
+ return;
+
+ if (stripe == dc->disk.nr_stripes) {
+ stripe = 0;
+ wrapped = true;
}
+ }
+}
+
+static bool refill_dirty(struct cached_dev *dc)
+{
+ struct keybuf *buf = &dc->writeback_keys;
+ struct bkey end = KEY(dc->disk.id, MAX_KEY_OFFSET, 0);
+ bool searched_from_start = false;
+
+ if (dc->partial_stripes_expensive) {
+ refill_full_stripes(dc);
+ if (array_freelist_empty(&buf->freelist))
+ return false;
+ }
+
+ if (bkey_cmp(&buf->last_scanned, &end) >= 0) {
+ buf->last_scanned = KEY(dc->disk.id, 0, 0);
+ searched_from_start = true;
+ }
+
+ bch_refill_keybuf(dc->disk.c, buf, &end, dirty_pred);
+
+ return bkey_cmp(&buf->last_scanned, &end) >= 0 && searched_from_start;
+}
+
+static int bch_writeback_thread(void *arg)
+{
+ struct cached_dev *dc = arg;
+ bool searched_full_index;
+
+ while (!kthread_should_stop()) {
+ down_write(&dc->writeback_lock);
+ if (!atomic_read(&dc->has_dirty) ||
+ (!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) &&
+ !dc->writeback_running)) {
+ up_write(&dc->writeback_lock);
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (kthread_should_stop())
+ return 0;
+
+ try_to_freeze();
+ schedule();
+ continue;
+ }
+
+ searched_full_index = refill_dirty(dc);
+
+ if (searched_full_index &&
+ RB_EMPTY_ROOT(&dc->writeback_keys.keys)) {
+ atomic_set(&dc->has_dirty, 0);
+ cached_dev_put(dc);
+ SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
+ bch_write_bdev_super(dc, NULL);
+ }
+
+ up_write(&dc->writeback_lock);
+
+ bch_ratelimit_reset(&dc->writeback_rate);
+ read_dirty(dc);
+
+ if (searched_full_index) {
+ unsigned delay = dc->writeback_delay * HZ;
+
+ while (delay &&
+ !kthread_should_stop() &&
+ !test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags))
+ delay = schedule_timeout_interruptible(delay);
+ }
+ }
return 0;
}
+/* Init */
+
+struct sectors_dirty_init {
+ struct btree_op op;
+ unsigned inode;
+};
+
+static int sectors_dirty_init_fn(struct btree_op *_op, struct btree *b,
+ struct bkey *k)
+{
+ struct sectors_dirty_init *op = container_of(_op,
+ struct sectors_dirty_init, op);
+ if (KEY_INODE(k) > op->inode)
+ return MAP_DONE;
+
+ if (KEY_DIRTY(k))
+ bcache_dev_sectors_dirty_add(b->c, KEY_INODE(k),
+ KEY_START(k), KEY_SIZE(k));
+
+ return MAP_CONTINUE;
+}
+
void bch_sectors_dirty_init(struct cached_dev *dc)
{
- struct btree_op op;
+ struct sectors_dirty_init op;
+
+ bch_btree_op_init(&op.op, -1);
+ op.inode = dc->disk.id;
- bch_btree_op_init_stack(&op);
- btree_root(sectors_dirty_init, dc->disk.c, &op, dc);
+ bch_btree_map_keys(&op.op, dc->disk.c, &KEY(op.inode, 0, 0),
+ sectors_dirty_init_fn, 0);
}
-void bch_cached_dev_writeback_init(struct cached_dev *dc)
+int bch_cached_dev_writeback_init(struct cached_dev *dc)
{
sema_init(&dc->in_flight, 64);
- closure_init_unlocked(&dc->writeback);
init_rwsem(&dc->writeback_lock);
-
bch_keybuf_init(&dc->writeback_keys);
dc->writeback_metadata = true;
dc->writeback_rate_p_term_inverse = 64;
dc->writeback_rate_d_smooth = 8;
+ dc->writeback_thread = kthread_create(bch_writeback_thread, dc,
+ "bcache_writeback");
+ if (IS_ERR(dc->writeback_thread))
+ return PTR_ERR(dc->writeback_thread);
+
+ set_task_state(dc->writeback_thread, TASK_INTERRUPTIBLE);
+
INIT_DELAYED_WORK(&dc->writeback_rate_update, update_writeback_rate);
schedule_delayed_work(&dc->writeback_rate_update,
dc->writeback_rate_update_seconds * HZ);
-}
-
-void bch_writeback_exit(void)
-{
- if (dirty_wq)
- destroy_workqueue(dirty_wq);
-}
-
-int __init bch_writeback_init(void)
-{
- dirty_wq = create_workqueue("bcache_writeback");
- if (!dirty_wq)
- return -ENOMEM;
return 0;
}
projects / deliverable / linux.git / blobdiff