bcache: remove driver private bio splitting code

The bcache driver has always accepted arbitrarily large bios and split
them internally.  Now that every driver must accept arbitrarily large
bios this code isn't nessecary anymore.

Cc: linux-bcache@vger.kernel.org
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[dpark: add more description in commit message]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

7 files changed, 18 insertions, 162 deletions

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 04f7bc28ef83..6b420a55c745 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -243,19 +243,6 @@ struct keybuf {
         DECLARE_ARRAY_ALLOCATOR(struct keybuf_key, freelist, KEYBUF_NR);
 };
 
-struct bio_split_pool {
-        struct bio_set          *bio_split;
-        mempool_t               *bio_split_hook;
-};
-
-struct bio_split_hook {
-        struct closure          cl;
-        struct bio_split_pool   *p;
-        struct bio              *bio;
-        bio_end_io_t            *bi_end_io;
-        void                    *bi_private;
-};
-
 struct bcache_device {
         struct closure          cl;
 
@@ -288,8 +275,6 @@ struct bcache_device {
         int (*cache_miss)(struct btree *, struct search *,
                           struct bio *, unsigned);
         int (*ioctl) (struct bcache_device *, fmode_t, unsigned, unsigned long);
-
-        struct bio_split_pool   bio_split_hook;
 };
 
 struct io {
@@ -454,8 +439,6 @@ struct cache {
         atomic_long_t           meta_sectors_written;
         atomic_long_t           btree_sectors_written;
         atomic_long_t           sectors_written;
-
-        struct bio_split_pool   bio_split_hook;
 };
 
 struct gc_stat {
@@ -873,7 +856,6 @@ void bch_bbio_endio(struct cache_set *, struct bio *, int, const char *);
 void bch_bbio_free(struct bio *, struct cache_set *);
 struct bio *bch_bbio_alloc(struct cache_set *);
 
-void bch_generic_make_request(struct bio *, struct bio_split_pool *);
 void __bch_submit_bbio(struct bio *, struct cache_set *);
 void bch_submit_bbio(struct bio *, struct cache_set *, struct bkey *, unsigned);
 
diff --git a/drivers/md/bcache/io.c b/drivers/md/bcache/io.c
index 9440df94bc83..86a0bb87124e 100644
--- a/drivers/md/bcache/io.c
+++ b/drivers/md/bcache/io.c
@@ -11,105 +11,6 @@
 
 #include <linux/blkdev.h>
 
-static unsigned bch_bio_max_sectors(struct bio *bio)
-{
-        struct request_queue *q = bdev_get_queue(bio->bi_bdev);
-        struct bio_vec bv;
-        struct bvec_iter iter;
-        unsigned ret = 0, seg = 0;
-
-        if (bio->bi_rw & REQ_DISCARD)
-                return min(bio_sectors(bio), q->limits.max_discard_sectors);
-
-        bio_for_each_segment(bv, bio, iter) {
-                struct bvec_merge_data bvm = {
-                        .bi_bdev        = bio->bi_bdev,
-                        .bi_sector      = bio->bi_iter.bi_sector,
-                        .bi_size        = ret << 9,
-                        .bi_rw          = bio->bi_rw,
-                };
-
-                if (seg == min_t(unsigned, BIO_MAX_PAGES,
-                                 queue_max_segments(q)))
-                        break;
-
-                if (q->merge_bvec_fn &&
-                    q->merge_bvec_fn(q, &bvm, &bv) < (int) bv.bv_len)
-                        break;
-
-                seg++;
-                ret += bv.bv_len >> 9;
-        }
-
-        ret = min(ret, queue_max_sectors(q));
-
-        WARN_ON(!ret);
-        ret = max_t(int, ret, bio_iovec(bio).bv_len >> 9);
-
-        return ret;
-}
-
-static void bch_bio_submit_split_done(struct closure *cl)
-{
-        struct bio_split_hook *s = container_of(cl, struct bio_split_hook, cl);
-
-        s->bio->bi_end_io = s->bi_end_io;
-        s->bio->bi_private = s->bi_private;
-        bio_endio(s->bio);
-
-        closure_debug_destroy(&s->cl);
-        mempool_free(s, s->p->bio_split_hook);
-}
-
-static void bch_bio_submit_split_endio(struct bio *bio)
-{
-        struct closure *cl = bio->bi_private;
-        struct bio_split_hook *s = container_of(cl, struct bio_split_hook, cl);
-
-        if (bio->bi_error)
-                s->bio->bi_error = bio->bi_error;
-
-        bio_put(bio);
-        closure_put(cl);
-}
-
-void bch_generic_make_request(struct bio *bio, struct bio_split_pool *p)
-{
-        struct bio_split_hook *s;
-        struct bio *n;
-
-        if (!bio_has_data(bio) && !(bio->bi_rw & REQ_DISCARD))
-                goto submit;
-
-        if (bio_sectors(bio) <= bch_bio_max_sectors(bio))
-                goto submit;
-
-        s = mempool_alloc(p->bio_split_hook, GFP_NOIO);
-        closure_init(&s->cl, NULL);
-
-        s->bio          = bio;
-        s->p            = p;
-        s->bi_end_io    = bio->bi_end_io;
-        s->bi_private   = bio->bi_private;
-        bio_get(bio);
-
-        do {
-                n = bio_next_split(bio, bch_bio_max_sectors(bio),
-                                   GFP_NOIO, s->p->bio_split);
-
-                n->bi_end_io    = bch_bio_submit_split_endio;
-                n->bi_private   = &s->cl;
-
-                closure_get(&s->cl);
-                generic_make_request(n);
-        } while (n != bio);
-
-        continue_at(&s->cl, bch_bio_submit_split_done, NULL);
-        return;
-submit:
-        generic_make_request(bio);
-}
-
 /* Bios with headers */
 
 void bch_bbio_free(struct bio *bio, struct cache_set *c)
@@ -139,7 +40,7 @@ void __bch_submit_bbio(struct bio *bio, struct cache_set *c)
         bio->bi_bdev            = PTR_CACHE(c, &b->key, 0)->bdev;
 
         b->submit_time_us = local_clock_us();
-        closure_bio_submit(bio, bio->bi_private, PTR_CACHE(c, &b->key, 0));
+        closure_bio_submit(bio, bio->bi_private);
 }
 
 void bch_submit_bbio(struct bio *bio, struct cache_set *c,
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index d6a4e16030a6..29eba7219b01 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -61,7 +61,7 @@ reread:		left = ca->sb.bucket_size - offset;
                 bio->bi_private = &cl;
                 bch_bio_map(bio, data);
 
-                closure_bio_submit(bio, &cl, ca);
+                closure_bio_submit(bio, &cl);
                 closure_sync(&cl);
 
                 /* This function could be simpler now since we no longer write
@@ -648,7 +648,7 @@ static void journal_write_unlocked(struct closure *cl)
         spin_unlock(&c->journal.lock);
 
         while ((bio = bio_list_pop(&list)))
-                closure_bio_submit(bio, cl, c->cache[0]);
+                closure_bio_submit(bio, cl);
 
         continue_at(cl, journal_write_done, NULL);
 }
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index a09b9462ff49..8e9877b04637 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -719,7 +719,7 @@ static void cached_dev_read_error(struct closure *cl)
 
                 /* XXX: invalidate cache */
 
-                closure_bio_submit(bio, cl, s->d);
+                closure_bio_submit(bio, cl);
         }
 
         continue_at(cl, cached_dev_cache_miss_done, NULL);
@@ -842,7 +842,7 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
         s->cache_miss   = miss;
         s->iop.bio      = cache_bio;
         bio_get(cache_bio);
-        closure_bio_submit(cache_bio, &s->cl, s->d);
+        closure_bio_submit(cache_bio, &s->cl);
 
         return ret;
 out_put:
@@ -850,7 +850,7 @@ out_put:
 out_submit:
         miss->bi_end_io         = request_endio;
         miss->bi_private        = &s->cl;
-        closure_bio_submit(miss, &s->cl, s->d);
+        closure_bio_submit(miss, &s->cl);
         return ret;
 }
 
@@ -915,7 +915,7 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s)
 
                 if (!(bio->bi_rw & REQ_DISCARD) ||
                     blk_queue_discard(bdev_get_queue(dc->bdev)))
-                        closure_bio_submit(bio, cl, s->d);
+                        closure_bio_submit(bio, cl);
         } else if (s->iop.writeback) {
                 bch_writeback_add(dc);
                 s->iop.bio = bio;
@@ -930,12 +930,12 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s)
                         flush->bi_end_io = request_endio;
                         flush->bi_private = cl;
 
-                        closure_bio_submit(flush, cl, s->d);
+                        closure_bio_submit(flush, cl);
                 }
         } else {
                 s->iop.bio = bio_clone_fast(bio, GFP_NOIO, dc->disk.bio_split);
 
-                closure_bio_submit(bio, cl, s->d);
+                closure_bio_submit(bio, cl);
         }
 
         closure_call(&s->iop.cl, bch_data_insert, NULL, cl);
@@ -951,7 +951,7 @@ static void cached_dev_nodata(struct closure *cl)
                 bch_journal_meta(s->iop.c, cl);
 
         /* If it's a flush, we send the flush to the backing device too */
-        closure_bio_submit(bio, cl, s->d);
+        closure_bio_submit(bio, cl);
 
         continue_at(cl, cached_dev_bio_complete, NULL);
 }
@@ -995,7 +995,7 @@ static void cached_dev_make_request(struct request_queue *q, struct bio *bio)
                     !blk_queue_discard(bdev_get_queue(dc->bdev)))
                         bio_endio(bio);
                 else
-                        bch_generic_make_request(bio, &d->bio_split_hook);
+                        generic_make_request(bio);
         }
 }
 
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index be01fd3c87f1..679a093a3bf6 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -59,29 +59,6 @@ struct workqueue_struct *bcache_wq;
 
 #define BTREE_MAX_PAGES         (256 * 1024 / PAGE_SIZE)
 
-static void bio_split_pool_free(struct bio_split_pool *p)
-{
-        if (p->bio_split_hook)
-                mempool_destroy(p->bio_split_hook);
-
-        if (p->bio_split)
-                bioset_free(p->bio_split);
-}
-
-static int bio_split_pool_init(struct bio_split_pool *p)
-{
-        p->bio_split = bioset_create(4, 0);
-        if (!p->bio_split)
-                return -ENOMEM;
-
-        p->bio_split_hook = mempool_create_kmalloc_pool(4,
-                                sizeof(struct bio_split_hook));
-        if (!p->bio_split_hook)
-                return -ENOMEM;
-
-        return 0;
-}
-
 /* Superblock */
 
 static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
@@ -537,7 +514,7 @@ static void prio_io(struct cache *ca, uint64_t bucket, unsigned long rw)
         bio->bi_private = ca;
         bch_bio_map(bio, ca->disk_buckets);
 
-        closure_bio_submit(bio, &ca->prio, ca);
+        closure_bio_submit(bio, &ca->prio);
         closure_sync(cl);
 }
 
@@ -757,7 +734,6 @@ static void bcache_device_free(struct bcache_device *d)
                 put_disk(d->disk);
         }
 
-        bio_split_pool_free(&d->bio_split_hook);
         if (d->bio_split)
                 bioset_free(d->bio_split);
         kvfree(d->full_dirty_stripes);
@@ -804,7 +780,6 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,
                 return minor;
 
         if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
-            bio_split_pool_init(&d->bio_split_hook) ||
             !(d->disk = alloc_disk(1))) {
                 ida_simple_remove(&bcache_minor, minor);
                 return -ENOMEM;
@@ -1793,8 +1768,6 @@ void bch_cache_release(struct kobject *kobj)
                 ca->set->cache[ca->sb.nr_this_dev] = NULL;
         }
 
-        bio_split_pool_free(&ca->bio_split_hook);
-
         free_pages((unsigned long) ca->disk_buckets, ilog2(bucket_pages(ca)));
         kfree(ca->prio_buckets);
         vfree(ca->buckets);
@@ -1839,8 +1812,7 @@ static int cache_alloc(struct cache_sb *sb, struct cache *ca)
                                           ca->sb.nbuckets)) ||
             !(ca->prio_buckets  = kzalloc(sizeof(uint64_t) * prio_buckets(ca) *
                                           2, GFP_KERNEL)) ||
-            !(ca->disk_buckets  = alloc_bucket_pages(GFP_KERNEL, ca)) ||
-            bio_split_pool_init(&ca->bio_split_hook))
+            !(ca->disk_buckets  = alloc_bucket_pages(GFP_KERNEL, ca)))
                 return -ENOMEM;
 
         ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);
diff --git a/drivers/md/bcache/util.h b/drivers/md/bcache/util.h
index 1d04c4859c70..cf2cbc211d83 100644
--- a/drivers/md/bcache/util.h
+++ b/drivers/md/bcache/util.h
@@ -4,6 +4,7 @@
 
 #include <linux/blkdev.h>
 #include <linux/errno.h>
+#include <linux/blkdev.h>
 #include <linux/kernel.h>
 #include <linux/llist.h>
 #include <linux/ratelimit.h>
@@ -570,10 +571,10 @@ static inline sector_t bdev_sectors(struct block_device *bdev)
         return bdev->bd_inode->i_size >> 9;
 }
 
-#define closure_bio_submit(bio, cl, dev)                                \
+#define closure_bio_submit(bio, cl)                                     \
 do {                                                                    \
         closure_get(cl);                                                \
-        bch_generic_make_request(bio, &(dev)->bio_split_hook);          \
+        generic_make_request(bio);                                      \
 } while (0)
 
 uint64_t bch_crc64_update(uint64_t, const void *, size_t);
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index b4fc874c30fd..b23f88d9f18c 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -188,7 +188,7 @@ static void write_dirty(struct closure *cl)
         io->bio.bi_bdev         = io->dc->bdev;
         io->bio.bi_end_io       = dirty_endio;
 
-        closure_bio_submit(&io->bio, cl, &io->dc->disk);
+        closure_bio_submit(&io->bio, cl);
 
         continue_at(cl, write_dirty_finish, system_wq);
 }
@@ -208,7 +208,7 @@ static void read_dirty_submit(struct closure *cl)
 {
         struct dirty_io *io = container_of(cl, struct dirty_io, cl);
 
-        closure_bio_submit(&io->bio, cl, &io->dc->disk);
+        closure_bio_submit(&io->bio, cl);
 
         continue_at(cl, write_dirty, system_wq);
 }