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Diffstat (limited to 'drivers/md/bcache/request.c')
-rw-r--r--drivers/md/bcache/request.c197
1 files changed, 79 insertions, 118 deletions
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index e5ff12e5..786a1a4 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -10,6 +10,7 @@
#include "btree.h"
#include "debug.h"
#include "request.h"
+#include "writeback.h"
#include <linux/cgroup.h>
#include <linux/module.h>
@@ -21,8 +22,6 @@
#define CUTOFF_CACHE_ADD 95
#define CUTOFF_CACHE_READA 90
-#define CUTOFF_WRITEBACK 50
-#define CUTOFF_WRITEBACK_SYNC 75
struct kmem_cache *bch_search_cache;
@@ -489,6 +488,12 @@ static void bch_insert_data_loop(struct closure *cl)
bch_queue_gc(op->c);
}
+ /*
+ * Journal writes are marked REQ_FLUSH; if the original write was a
+ * flush, it'll wait on the journal write.
+ */
+ bio->bi_rw &= ~(REQ_FLUSH|REQ_FUA);
+
do {
unsigned i;
struct bkey *k;
@@ -510,10 +515,6 @@ static void bch_insert_data_loop(struct closure *cl)
goto err;
n = bch_bio_split(bio, KEY_SIZE(k), GFP_NOIO, split);
- if (!n) {
- __bkey_put(op->c, k);
- continue_at(cl, bch_insert_data_loop, bcache_wq);
- }
n->bi_end_io = bch_insert_data_endio;
n->bi_private = cl;
@@ -530,10 +531,9 @@ static void bch_insert_data_loop(struct closure *cl)
if (KEY_CSUM(k))
bio_csum(n, k);
- pr_debug("%s", pkey(k));
+ trace_bcache_cache_insert(k);
bch_keylist_push(&op->keys);
- trace_bcache_cache_insert(n, n->bi_sector, n->bi_bdev);
n->bi_rw |= REQ_WRITE;
bch_submit_bbio(n, op->c, k, 0);
} while (n != bio);
@@ -716,7 +716,7 @@ static struct search *search_alloc(struct bio *bio, struct bcache_device *d)
s->task = current;
s->orig_bio = bio;
s->write = (bio->bi_rw & REQ_WRITE) != 0;
- s->op.flush_journal = (bio->bi_rw & REQ_FLUSH) != 0;
+ s->op.flush_journal = (bio->bi_rw & (REQ_FLUSH|REQ_FUA)) != 0;
s->op.skip = (bio->bi_rw & REQ_DISCARD) != 0;
s->recoverable = 1;
s->start_time = jiffies;
@@ -784,11 +784,8 @@ static void request_read_error(struct closure *cl)
int i;
if (s->recoverable) {
- /* The cache read failed, but we can retry from the backing
- * device.
- */
- pr_debug("recovering at sector %llu",
- (uint64_t) s->orig_bio->bi_sector);
+ /* Retry from the backing device: */
+ trace_bcache_read_retry(s->orig_bio);
s->error = 0;
bv = s->bio.bio.bi_io_vec;
@@ -806,7 +803,6 @@ static void request_read_error(struct closure *cl)
/* XXX: invalidate cache */
- trace_bcache_read_retry(&s->bio.bio);
closure_bio_submit(&s->bio.bio, &s->cl, s->d);
}
@@ -827,53 +823,13 @@ static void request_read_done(struct closure *cl)
*/
if (s->op.cache_bio) {
- struct bio_vec *src, *dst;
- unsigned src_offset, dst_offset, bytes;
- void *dst_ptr;
-
bio_reset(s->op.cache_bio);
s->op.cache_bio->bi_sector = s->cache_miss->bi_sector;
s->op.cache_bio->bi_bdev = s->cache_miss->bi_bdev;
s->op.cache_bio->bi_size = s->cache_bio_sectors << 9;
bch_bio_map(s->op.cache_bio, NULL);
- src = bio_iovec(s->op.cache_bio);
- dst = bio_iovec(s->cache_miss);
- src_offset = src->bv_offset;
- dst_offset = dst->bv_offset;
- dst_ptr = kmap(dst->bv_page);
-
- while (1) {
- if (dst_offset == dst->bv_offset + dst->bv_len) {
- kunmap(dst->bv_page);
- dst++;
- if (dst == bio_iovec_idx(s->cache_miss,
- s->cache_miss->bi_vcnt))
- break;
-
- dst_offset = dst->bv_offset;
- dst_ptr = kmap(dst->bv_page);
- }
-
- if (src_offset == src->bv_offset + src->bv_len) {
- src++;
- if (src == bio_iovec_idx(s->op.cache_bio,
- s->op.cache_bio->bi_vcnt))
- BUG();
-
- src_offset = src->bv_offset;
- }
-
- bytes = min(dst->bv_offset + dst->bv_len - dst_offset,
- src->bv_offset + src->bv_len - src_offset);
-
- memcpy(dst_ptr + dst_offset,
- page_address(src->bv_page) + src_offset,
- bytes);
-
- src_offset += bytes;
- dst_offset += bytes;
- }
+ bio_copy_data(s->cache_miss, s->op.cache_bio);
bio_put(s->cache_miss);
s->cache_miss = NULL;
@@ -899,6 +855,7 @@ static void request_read_done_bh(struct closure *cl)
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
bch_mark_cache_accounting(s, !s->cache_miss, s->op.skip);
+ trace_bcache_read(s->orig_bio, !s->cache_miss, s->op.skip);
if (s->error)
continue_at_nobarrier(cl, request_read_error, bcache_wq);
@@ -917,9 +874,6 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
struct bio *miss;
miss = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split);
- if (!miss)
- return -EAGAIN;
-
if (miss == bio)
s->op.lookup_done = true;
@@ -938,8 +892,9 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
reada = min(dc->readahead >> 9,
sectors - bio_sectors(miss));
- if (bio_end(miss) + reada > bdev_sectors(miss->bi_bdev))
- reada = bdev_sectors(miss->bi_bdev) - bio_end(miss);
+ if (bio_end_sector(miss) + reada > bdev_sectors(miss->bi_bdev))
+ reada = bdev_sectors(miss->bi_bdev) -
+ bio_end_sector(miss);
}
s->cache_bio_sectors = bio_sectors(miss) + reada;
@@ -963,13 +918,12 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
goto out_put;
bch_bio_map(s->op.cache_bio, NULL);
- if (bch_bio_alloc_pages(s->op.cache_bio, __GFP_NOWARN|GFP_NOIO))
+ if (bio_alloc_pages(s->op.cache_bio, __GFP_NOWARN|GFP_NOIO))
goto out_put;
s->cache_miss = miss;
bio_get(s->op.cache_bio);
- trace_bcache_cache_miss(s->orig_bio);
closure_bio_submit(s->op.cache_bio, &s->cl, s->d);
return ret;
@@ -1002,24 +956,13 @@ static void cached_dev_write_complete(struct closure *cl)
cached_dev_bio_complete(cl);
}
-static bool should_writeback(struct cached_dev *dc, struct bio *bio)
-{
- unsigned threshold = (bio->bi_rw & REQ_SYNC)
- ? CUTOFF_WRITEBACK_SYNC
- : CUTOFF_WRITEBACK;
-
- return !atomic_read(&dc->disk.detaching) &&
- cache_mode(dc, bio) == CACHE_MODE_WRITEBACK &&
- dc->disk.c->gc_stats.in_use < threshold;
-}
-
static void request_write(struct cached_dev *dc, struct search *s)
{
struct closure *cl = &s->cl;
struct bio *bio = &s->bio.bio;
struct bkey start, end;
start = KEY(dc->disk.id, bio->bi_sector, 0);
- end = KEY(dc->disk.id, bio_end(bio), 0);
+ end = KEY(dc->disk.id, bio_end_sector(bio), 0);
bch_keybuf_check_overlapping(&s->op.c->moving_gc_keys, &start, &end);
@@ -1034,22 +977,37 @@ static void request_write(struct cached_dev *dc, struct search *s)
if (bio->bi_rw & REQ_DISCARD)
goto skip;
+ if (should_writeback(dc, s->orig_bio,
+ cache_mode(dc, bio),
+ s->op.skip)) {
+ s->op.skip = false;
+ s->writeback = true;
+ }
+
if (s->op.skip)
goto skip;
- if (should_writeback(dc, s->orig_bio))
- s->writeback = true;
+ trace_bcache_write(s->orig_bio, s->writeback, s->op.skip);
if (!s->writeback) {
s->op.cache_bio = bio_clone_bioset(bio, GFP_NOIO,
dc->disk.bio_split);
- trace_bcache_writethrough(s->orig_bio);
closure_bio_submit(bio, cl, s->d);
} else {
- s->op.cache_bio = bio;
- trace_bcache_writeback(s->orig_bio);
- bch_writeback_add(dc, bio_sectors(bio));
+ bch_writeback_add(dc);
+
+ if (s->op.flush_journal) {
+ /* Also need to send a flush to the backing device */
+ s->op.cache_bio = bio_clone_bioset(bio, GFP_NOIO,
+ dc->disk.bio_split);
+
+ bio->bi_size = 0;
+ bio->bi_vcnt = 0;
+ closure_bio_submit(bio, cl, s->d);
+ } else {
+ s->op.cache_bio = bio;
+ }
}
out:
closure_call(&s->op.cl, bch_insert_data, NULL, cl);
@@ -1058,7 +1016,6 @@ skip:
s->op.skip = true;
s->op.cache_bio = s->orig_bio;
bio_get(s->op.cache_bio);
- trace_bcache_write_skip(s->orig_bio);
if ((bio->bi_rw & REQ_DISCARD) &&
!blk_queue_discard(bdev_get_queue(dc->bdev)))
@@ -1088,9 +1045,10 @@ static void request_nodata(struct cached_dev *dc, struct search *s)
/* Cached devices - read & write stuff */
-int bch_get_congested(struct cache_set *c)
+unsigned bch_get_congested(struct cache_set *c)
{
int i;
+ long rand;
if (!c->congested_read_threshold_us &&
!c->congested_write_threshold_us)
@@ -1106,7 +1064,13 @@ int bch_get_congested(struct cache_set *c)
i += CONGESTED_MAX;
- return i <= 0 ? 1 : fract_exp_two(i, 6);
+ if (i > 0)
+ i = fract_exp_two(i, 6);
+
+ rand = get_random_int();
+ i -= bitmap_weight(&rand, BITS_PER_LONG);
+
+ return i > 0 ? i : 1;
}
static void add_sequential(struct task_struct *t)
@@ -1126,10 +1090,8 @@ static void check_should_skip(struct cached_dev *dc, struct search *s)
{
struct cache_set *c = s->op.c;
struct bio *bio = &s->bio.bio;
-
- long rand;
- int cutoff = bch_get_congested(c);
unsigned mode = cache_mode(dc, bio);
+ unsigned sectors, congested = bch_get_congested(c);
if (atomic_read(&dc->disk.detaching) ||
c->gc_stats.in_use > CUTOFF_CACHE_ADD ||
@@ -1147,17 +1109,14 @@ static void check_should_skip(struct cached_dev *dc, struct search *s)
goto skip;
}
- if (!cutoff) {
- cutoff = dc->sequential_cutoff >> 9;
+ if (!congested && !dc->sequential_cutoff)
+ goto rescale;
- if (!cutoff)
- goto rescale;
-
- if (mode == CACHE_MODE_WRITEBACK &&
- (bio->bi_rw & REQ_WRITE) &&
- (bio->bi_rw & REQ_SYNC))
- goto rescale;
- }
+ if (!congested &&
+ mode == CACHE_MODE_WRITEBACK &&
+ (bio->bi_rw & REQ_WRITE) &&
+ (bio->bi_rw & REQ_SYNC))
+ goto rescale;
if (dc->sequential_merge) {
struct io *i;
@@ -1177,7 +1136,7 @@ found:
if (i->sequential + bio->bi_size > i->sequential)
i->sequential += bio->bi_size;
- i->last = bio_end(bio);
+ i->last = bio_end_sector(bio);
i->jiffies = jiffies + msecs_to_jiffies(5000);
s->task->sequential_io = i->sequential;
@@ -1192,12 +1151,19 @@ found:
add_sequential(s->task);
}
- rand = get_random_int();
- cutoff -= bitmap_weight(&rand, BITS_PER_LONG);
+ sectors = max(s->task->sequential_io,
+ s->task->sequential_io_avg) >> 9;
- if (cutoff <= (int) (max(s->task->sequential_io,
- s->task->sequential_io_avg) >> 9))
+ if (dc->sequential_cutoff &&
+ sectors >= dc->sequential_cutoff >> 9) {
+ trace_bcache_bypass_sequential(s->orig_bio);
goto skip;
+ }
+
+ if (congested && sectors >= congested) {
+ trace_bcache_bypass_congested(s->orig_bio);
+ goto skip;
+ }
rescale:
bch_rescale_priorities(c, bio_sectors(bio));
@@ -1288,30 +1254,25 @@ void bch_cached_dev_request_init(struct cached_dev *dc)
static int flash_dev_cache_miss(struct btree *b, struct search *s,
struct bio *bio, unsigned sectors)
{
+ struct bio_vec *bv;
+ int i;
+
/* Zero fill bio */
- while (bio->bi_idx != bio->bi_vcnt) {
- struct bio_vec *bv = bio_iovec(bio);
+ bio_for_each_segment(bv, bio, i) {
unsigned j = min(bv->bv_len >> 9, sectors);
void *p = kmap(bv->bv_page);
memset(p + bv->bv_offset, 0, j << 9);
kunmap(bv->bv_page);
- bv->bv_len -= j << 9;
- bv->bv_offset += j << 9;
-
- if (bv->bv_len)
- return 0;
-
- bio->bi_sector += j;
- bio->bi_size -= j << 9;
-
- bio->bi_idx++;
- sectors -= j;
+ sectors -= j;
}
- s->op.lookup_done = true;
+ bio_advance(bio, min(sectors << 9, bio->bi_size));
+
+ if (!bio->bi_size)
+ s->op.lookup_done = true;
return 0;
}
@@ -1338,8 +1299,8 @@ static void flash_dev_make_request(struct request_queue *q, struct bio *bio)
closure_call(&s->op.cl, btree_read_async, NULL, cl);
} else if (bio_has_data(bio) || s->op.skip) {
bch_keybuf_check_overlapping(&s->op.c->moving_gc_keys,
- &KEY(d->id, bio->bi_sector, 0),
- &KEY(d->id, bio_end(bio), 0));
+ &KEY(d->id, bio->bi_sector, 0),
+ &KEY(d->id, bio_end_sector(bio), 0));
s->writeback = true;
s->op.cache_bio = bio;
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