bcache: Convert bch_btree_read_async() to bch_btree_map_keys()
authorKent Overstreet <kmo@daterainc.com>
Thu, 25 Jul 2013 00:41:08 +0000 (17:41 -0700)
committerKent Overstreet <kmo@daterainc.com>
Mon, 11 Nov 2013 05:56:07 +0000 (21:56 -0800)
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 <kmo@daterainc.com>
drivers/md/bcache/btree.c
drivers/md/bcache/btree.h
drivers/md/bcache/journal.c
drivers/md/bcache/request.c
drivers/md/bcache/request.h

index bfd60e6..3949673 100644 (file)
@@ -23,7 +23,6 @@
 #include "bcache.h"
 #include "btree.h"
 #include "debug.h"
-#include "request.h"
 #include "writeback.h"
 
 #include <linux/slab.h>
@@ -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,
index 1690f47..60dadd7 100644 (file)
@@ -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 *);
index 8866f8e..6f4daf0 100644 (file)
@@ -7,7 +7,6 @@
 #include "bcache.h"
 #include "btree.h"
 #include "debug.h"
-#include "request.h"
 
 #include <trace/events/bcache.h>
 
index a168725..854743e 100644 (file)
@@ -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);
index 7d02ac5..b0b4b0b 100644 (file)
@@ -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 *);