bcache: Use blkdev_issue_discard()
The old asynchronous discard code was really a relic from when all the
allocation code was asynchronous - now that allocation runs out of a
dedicated thread there's no point in keeping around all that complicated
machinery.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
index e45f557..e033b02 100644
--- a/drivers/md/bcache/alloc.c
+++ b/drivers/md/bcache/alloc.c
@@ -63,13 +63,12 @@
#include "bcache.h"
#include "btree.h"
+#include <linux/blkdev.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/random.h>
#include <trace/events/bcache.h>
-#define MAX_IN_FLIGHT_DISCARDS 8U
-
/* Bucket heap / gen */
uint8_t bch_inc_gen(struct cache *ca, struct bucket *b)
@@ -121,75 +120,6 @@
mutex_unlock(&c->bucket_lock);
}
-/* Discard/TRIM */
-
-struct discard {
- struct list_head list;
- struct work_struct work;
- struct cache *ca;
- long bucket;
-
- struct bio bio;
- struct bio_vec bv;
-};
-
-static void discard_finish(struct work_struct *w)
-{
- struct discard *d = container_of(w, struct discard, work);
- struct cache *ca = d->ca;
- char buf[BDEVNAME_SIZE];
-
- if (!test_bit(BIO_UPTODATE, &d->bio.bi_flags)) {
- pr_notice("discard error on %s, disabling",
- bdevname(ca->bdev, buf));
- d->ca->discard = 0;
- }
-
- mutex_lock(&ca->set->bucket_lock);
-
- fifo_push(&ca->free, d->bucket);
- list_add(&d->list, &ca->discards);
- atomic_dec(&ca->discards_in_flight);
-
- mutex_unlock(&ca->set->bucket_lock);
-
- closure_wake_up(&ca->set->bucket_wait);
- wake_up_process(ca->alloc_thread);
-
- closure_put(&ca->set->cl);
-}
-
-static void discard_endio(struct bio *bio, int error)
-{
- struct discard *d = container_of(bio, struct discard, bio);
- schedule_work(&d->work);
-}
-
-static void do_discard(struct cache *ca, long bucket)
-{
- struct discard *d = list_first_entry(&ca->discards,
- struct discard, list);
-
- list_del(&d->list);
- d->bucket = bucket;
-
- atomic_inc(&ca->discards_in_flight);
- closure_get(&ca->set->cl);
-
- bio_init(&d->bio);
-
- d->bio.bi_sector = bucket_to_sector(ca->set, d->bucket);
- d->bio.bi_bdev = ca->bdev;
- d->bio.bi_rw = REQ_WRITE|REQ_DISCARD;
- d->bio.bi_max_vecs = 1;
- d->bio.bi_io_vec = d->bio.bi_inline_vecs;
- d->bio.bi_size = bucket_bytes(ca);
- d->bio.bi_end_io = discard_endio;
- bio_set_prio(&d->bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
-
- submit_bio(0, &d->bio);
-}
-
/* Allocation */
static inline bool can_inc_bucket_gen(struct bucket *b)
@@ -398,16 +328,18 @@
else
break;
- allocator_wait(ca, (int) fifo_free(&ca->free) >
- atomic_read(&ca->discards_in_flight));
-
if (ca->discard) {
- allocator_wait(ca, !list_empty(&ca->discards));
- do_discard(ca, bucket);
- } else {
- fifo_push(&ca->free, bucket);
- closure_wake_up(&ca->set->bucket_wait);
+ mutex_unlock(&ca->set->bucket_lock);
+ blkdev_issue_discard(ca->bdev,
+ bucket_to_sector(ca->set, bucket),
+ ca->sb.block_size, GFP_KERNEL, 0);
+ mutex_lock(&ca->set->bucket_lock);
}
+
+ allocator_wait(ca, !fifo_full(&ca->free));
+
+ fifo_push(&ca->free, bucket);
+ closure_wake_up(&ca->set->bucket_wait);
}
/*
@@ -556,22 +488,8 @@
return 0;
}
-void bch_cache_allocator_exit(struct cache *ca)
-{
- struct discard *d;
-
- while (!list_empty(&ca->discards)) {
- d = list_first_entry(&ca->discards, struct discard, list);
- cancel_work_sync(&d->work);
- list_del(&d->list);
- kfree(d);
- }
-}
-
int bch_cache_allocator_init(struct cache *ca)
{
- unsigned i;
-
/*
* Reserve:
* Prio/gen writes first
@@ -589,15 +507,5 @@
ca->watermark[WATERMARK_NONE] = ca->free.size / 2 +
ca->watermark[WATERMARK_MOVINGGC];
- for (i = 0; i < MAX_IN_FLIGHT_DISCARDS; i++) {
- struct discard *d = kzalloc(sizeof(*d), GFP_KERNEL);
- if (!d)
- return -ENOMEM;
-
- d->ca = ca;
- INIT_WORK(&d->work, discard_finish);
- list_add(&d->list, &ca->discards);
- }
-
return 0;
}