From 2c1953e201a05ddfb1ea53f23d81a492c6513028 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Wed, 24 Jul 2013 17:41:08 -0700 Subject: [PATCH] bcache: Convert bch_btree_read_async() to bch_btree_map_keys() This is a fairly straightforward conversion, mostly reshuffling - op->lookup_done goes away, replaced by MAP_DONE/MAP_CONTINUE. And the code for handling cache hits and misses wasn't really btree code, so it gets moved to request.c. Signed-off-by: Kent Overstreet --- drivers/md/bcache/btree.c | 133 ------------------------------- drivers/md/bcache/btree.h | 3 - drivers/md/bcache/journal.c | 1 - drivers/md/bcache/request.c | 154 +++++++++++++++++++++++++++++------- drivers/md/bcache/request.h | 2 - 5 files changed, 125 insertions(+), 168 deletions(-) diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index bfd60e6a2312..3949673cb1b0 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -23,7 +23,6 @@ #include "bcache.h" #include "btree.h" #include "debug.h" -#include "request.h" #include "writeback.h" #include @@ -2255,138 +2254,6 @@ void bch_btree_set_root(struct btree *b) closure_sync(&cl); } -/* Cache lookup */ - -static int submit_partial_cache_miss(struct btree *b, struct btree_op *op, - struct bkey *k) -{ - struct search *s = container_of(op, struct search, op); - struct bio *bio = &s->bio.bio; - int ret = 0; - - while (!ret && - !op->lookup_done) { - unsigned sectors = INT_MAX; - - if (KEY_INODE(k) == op->inode) { - if (KEY_START(k) <= bio->bi_sector) - break; - - sectors = min_t(uint64_t, sectors, - KEY_START(k) - bio->bi_sector); - } - - ret = s->d->cache_miss(b, s, bio, sectors); - } - - return ret; -} - -/* - * Read from a single key, handling the initial cache miss if the key starts in - * the middle of the bio - */ -static int submit_partial_cache_hit(struct btree *b, struct btree_op *op, - struct bkey *k) -{ - struct search *s = container_of(op, struct search, op); - struct bio *bio = &s->bio.bio; - unsigned ptr; - struct bio *n; - - int ret = submit_partial_cache_miss(b, op, k); - if (ret || op->lookup_done) - return ret; - - /* XXX: figure out best pointer - for multiple cache devices */ - ptr = 0; - - PTR_BUCKET(b->c, k, ptr)->prio = INITIAL_PRIO; - - while (!op->lookup_done && - KEY_INODE(k) == op->inode && - bio->bi_sector < KEY_OFFSET(k)) { - struct bkey *bio_key; - sector_t sector = PTR_OFFSET(k, ptr) + - (bio->bi_sector - KEY_START(k)); - unsigned sectors = min_t(uint64_t, INT_MAX, - KEY_OFFSET(k) - bio->bi_sector); - - n = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split); - if (n == bio) - op->lookup_done = true; - - bio_key = &container_of(n, struct bbio, bio)->key; - - /* - * The bucket we're reading from might be reused while our bio - * is in flight, and we could then end up reading the wrong - * data. - * - * We guard against this by checking (in cache_read_endio()) if - * the pointer is stale again; if so, we treat it as an error - * and reread from the backing device (but we don't pass that - * error up anywhere). - */ - - bch_bkey_copy_single_ptr(bio_key, k, ptr); - SET_PTR_OFFSET(bio_key, 0, sector); - - n->bi_end_io = bch_cache_read_endio; - n->bi_private = &s->cl; - - __bch_submit_bbio(n, b->c); - } - - return 0; -} - -static int bch_btree_search_recurse(struct btree *b, struct btree_op *op) -{ - struct search *s = container_of(op, struct search, op); - struct bio *bio = &s->bio.bio; - - int ret = 0; - struct bkey *k; - struct btree_iter iter; - bch_btree_iter_init(b, &iter, &KEY(op->inode, bio->bi_sector, 0)); - - do { - k = bch_btree_iter_next_filter(&iter, b, bch_ptr_bad); - if (!k) { - /* - * b->key would be exactly what we want, except that - * pointers to btree nodes have nonzero size - we - * wouldn't go far enough - */ - - ret = submit_partial_cache_miss(b, op, - &KEY(KEY_INODE(&b->key), - KEY_OFFSET(&b->key), 0)); - break; - } - - ret = b->level - ? btree(search_recurse, k, b, op) - : submit_partial_cache_hit(b, op, k); - } while (!ret && - !op->lookup_done); - - return ret; -} - -void bch_btree_search_async(struct closure *cl) -{ - struct btree_op *op = container_of(cl, struct btree_op, cl); - - int ret = btree_root(search_recurse, op->c, op); - - if (ret == -EAGAIN) - continue_at(cl, bch_btree_search_async, bcache_wq); - - closure_return(cl); -} - /* Map across nodes or keys */ static int bch_btree_map_nodes_recurse(struct btree *b, struct btree_op *op, diff --git a/drivers/md/bcache/btree.h b/drivers/md/bcache/btree.h index 1690f4731c1e..60dadd722ace 100644 --- a/drivers/md/bcache/btree.h +++ b/drivers/md/bcache/btree.h @@ -264,7 +264,6 @@ struct btree_op { unsigned flush_journal:1; unsigned insert_data_done:1; - unsigned lookup_done:1; unsigned insert_collision:1; BKEY_PADDED(replace); @@ -306,8 +305,6 @@ int bch_btree_insert_check_key(struct btree *, struct btree_op *, struct bkey *); int bch_btree_insert(struct btree_op *, struct cache_set *, struct keylist *); -void bch_btree_search_async(struct closure *); - int bch_gc_thread_start(struct cache_set *); size_t bch_btree_gc_finish(struct cache_set *); void bch_moving_gc(struct cache_set *); diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c index 8866f8ee3a07..6f4daf031410 100644 --- a/drivers/md/bcache/journal.c +++ b/drivers/md/bcache/journal.c @@ -7,7 +7,6 @@ #include "bcache.h" #include "btree.h" #include "debug.h" -#include "request.h" #include diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index a16872541038..854743e85e76 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -638,24 +638,9 @@ void bch_data_insert(struct closure *cl) bch_data_insert_start(cl); } -/* Common code for the make_request functions */ +/* Cache lookup */ -static void request_endio(struct bio *bio, int error) -{ - struct closure *cl = bio->bi_private; - - if (error) { - struct search *s = container_of(cl, struct search, cl); - s->error = error; - /* Only cache read errors are recoverable */ - s->recoverable = false; - } - - bio_put(bio); - closure_put(cl); -} - -void bch_cache_read_endio(struct bio *bio, int error) +static void bch_cache_read_endio(struct bio *bio, int error) { struct bbio *b = container_of(bio, struct bbio, bio); struct closure *cl = bio->bi_private; @@ -678,6 +663,120 @@ void bch_cache_read_endio(struct bio *bio, int error) bch_bbio_endio(s->op.c, bio, error, "reading from cache"); } +static int submit_partial_cache_miss(struct btree *b, struct search *s, + struct bkey *k) +{ + struct bio *bio = &s->bio.bio; + int ret = MAP_CONTINUE; + + do { + unsigned sectors = INT_MAX; + + if (KEY_INODE(k) == s->op.inode) { + if (KEY_START(k) <= bio->bi_sector) + break; + + sectors = min_t(uint64_t, sectors, + KEY_START(k) - bio->bi_sector); + } + + ret = s->d->cache_miss(b, s, bio, sectors); + } while (ret == MAP_CONTINUE); + + return ret; +} + +/* + * Read from a single key, handling the initial cache miss if the key starts in + * the middle of the bio + */ +static int submit_partial_cache_hit(struct btree_op *op, struct btree *b, + struct bkey *k) +{ + struct search *s = container_of(op, struct search, op); + struct bio *bio = &s->bio.bio; + unsigned ptr; + struct bio *n; + + int ret = submit_partial_cache_miss(b, s, k); + if (ret != MAP_CONTINUE || !KEY_SIZE(k)) + return ret; + + /* XXX: figure out best pointer - for multiple cache devices */ + ptr = 0; + + PTR_BUCKET(b->c, k, ptr)->prio = INITIAL_PRIO; + + while (ret == MAP_CONTINUE && + KEY_INODE(k) == op->inode && + bio->bi_sector < KEY_OFFSET(k)) { + struct bkey *bio_key; + sector_t sector = PTR_OFFSET(k, ptr) + + (bio->bi_sector - KEY_START(k)); + unsigned sectors = min_t(uint64_t, INT_MAX, + KEY_OFFSET(k) - bio->bi_sector); + + n = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split); + if (n == bio) + ret = MAP_DONE; + + bio_key = &container_of(n, struct bbio, bio)->key; + + /* + * The bucket we're reading from might be reused while our bio + * is in flight, and we could then end up reading the wrong + * data. + * + * We guard against this by checking (in cache_read_endio()) if + * the pointer is stale again; if so, we treat it as an error + * and reread from the backing device (but we don't pass that + * error up anywhere). + */ + + bch_bkey_copy_single_ptr(bio_key, k, ptr); + SET_PTR_OFFSET(bio_key, 0, sector); + + n->bi_end_io = bch_cache_read_endio; + n->bi_private = &s->cl; + + __bch_submit_bbio(n, b->c); + } + + return ret; +} + +static void cache_lookup(struct closure *cl) +{ + struct btree_op *op = container_of(cl, struct btree_op, cl); + struct search *s = container_of(op, struct search, op); + struct bio *bio = &s->bio.bio; + + int ret = bch_btree_map_keys(op, op->c, + &KEY(op->inode, bio->bi_sector, 0), + submit_partial_cache_hit, 1); + if (ret == -EAGAIN) + continue_at(cl, cache_lookup, bcache_wq); + + closure_return(cl); +} + +/* Common code for the make_request functions */ + +static void request_endio(struct bio *bio, int error) +{ + struct closure *cl = bio->bi_private; + + if (error) { + struct search *s = container_of(cl, struct search, cl); + s->error = error; + /* Only cache read errors are recoverable */ + s->recoverable = false; + } + + bio_put(bio); + closure_put(cl); +} + static void bio_complete(struct search *s) { if (s->orig_bio) { @@ -1005,15 +1104,14 @@ static void cached_dev_read_done_bh(struct closure *cl) static int cached_dev_cache_miss(struct btree *b, struct search *s, struct bio *bio, unsigned sectors) { - int ret = 0; + int ret = MAP_CONTINUE; unsigned reada = 0; struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); struct bio *miss, *cache_bio; if (s->cache_miss || s->op.bypass) { miss = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split); - if (miss == bio) - s->op.lookup_done = true; + ret = miss == bio ? MAP_DONE : MAP_CONTINUE; goto out_submit; } @@ -1033,11 +1131,9 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, return ret; miss = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split); - if (miss == bio) - s->op.lookup_done = true; - else - /* btree_search_recurse()'s btree iterator is no good anymore */ - ret = -EINTR; + + /* btree_search_recurse()'s btree iterator is no good anymore */ + ret = miss == bio ? MAP_DONE : -EINTR; cache_bio = bio_alloc_bioset(GFP_NOWAIT, DIV_ROUND_UP(s->cache_bio_sectors, PAGE_SECTORS), @@ -1075,7 +1171,7 @@ static void cached_dev_read(struct cached_dev *dc, struct search *s) { struct closure *cl = &s->cl; - closure_call(&s->op.cl, bch_btree_search_async, NULL, cl); + closure_call(&s->op.cl, cache_lookup, NULL, cl); continue_at(cl, cached_dev_read_done_bh, NULL); } @@ -1287,9 +1383,9 @@ static int flash_dev_cache_miss(struct btree *b, struct search *s, bio_advance(bio, min(sectors << 9, bio->bi_size)); if (!bio->bi_size) - s->op.lookup_done = true; + return MAP_DONE; - return 0; + return MAP_CONTINUE; } static void flash_dev_nodata(struct closure *cl) @@ -1339,7 +1435,7 @@ static void flash_dev_make_request(struct request_queue *q, struct bio *bio) closure_call(&s->op.cl, bch_data_insert, NULL, cl); } else { - closure_call(&s->op.cl, bch_btree_search_async, NULL, cl); + closure_call(&s->op.cl, cache_lookup, NULL, cl); } continue_at(cl, search_free, NULL); diff --git a/drivers/md/bcache/request.h b/drivers/md/bcache/request.h index 7d02ac5f936e..b0b4b0b5b7e9 100644 --- a/drivers/md/bcache/request.h +++ b/drivers/md/bcache/request.h @@ -31,10 +31,8 @@ struct search { struct keylist insert_keys; }; -void bch_cache_read_endio(struct bio *, int); unsigned bch_get_congested(struct cache_set *); void bch_data_insert(struct closure *cl); -void bch_cache_read_endio(struct bio *, int); void bch_open_buckets_free(struct cache_set *); int bch_open_buckets_alloc(struct cache_set *);