bcache: Break up struct search

With all the recent refactoring around struct btree op struct search has
gotten rather large.

But we can now easily break it up in a different way - we break out
struct btree_insert_op which is for inserting data into the cache, and
that's now what the copying gc code uses - struct search is now specific
to request.c

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

1 files changed, 303 insertions, 277 deletions

diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 6cee2ae1d87f..05c7c216f65e 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -215,9 +215,9 @@ static void bio_csum(struct bio *bio, struct bkey *k)
 
 static void bch_data_insert_keys(struct closure *cl)
 {
-        struct search *s = container_of(cl, struct search, btree);
+        struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
         atomic_t *journal_ref = NULL;
-        struct bkey *replace_key = s->replace ? &s->replace_key : NULL;
+        struct bkey *replace_key = op->replace ? &op->replace_key : NULL;
         int ret;
 
         /*
@@ -232,27 +232,26 @@ static void bch_data_insert_keys(struct closure *cl)
                 closure_sync(&s->cl);
 #endif
 
-        if (s->write)
-                journal_ref = bch_journal(s->c, &s->insert_keys,
-                                          s->flush_journal
-                                          ? &s->cl : NULL);
+        if (!op->replace)
+                journal_ref = bch_journal(op->c, &op->insert_keys,
+                                          op->flush_journal ? cl : NULL);
 
-        ret = bch_btree_insert(s->c, &s->insert_keys,
+        ret = bch_btree_insert(op->c, &op->insert_keys,
                                journal_ref, replace_key);
         if (ret == -ESRCH) {
-                s->insert_collision = true;
+                op->replace_collision = true;
         } else if (ret) {
-                s->error                = -ENOMEM;
-                s->insert_data_done     = true;
+                op->error               = -ENOMEM;
+                op->insert_data_done    = true;
         }
 
         if (journal_ref)
                 atomic_dec_bug(journal_ref);
 
-        if (!s->insert_data_done)
+        if (!op->insert_data_done)
                 continue_at(cl, bch_data_insert_start, bcache_wq);
 
-        bch_keylist_free(&s->insert_keys);
+        bch_keylist_free(&op->insert_keys);
         closure_return(cl);
 }
 
@@ -349,10 +348,10 @@ found:
  *
  * If s->writeback is true, will not fail.
  */
-static bool bch_alloc_sectors(struct bkey *k, unsigned sectors,
-                              struct search *s)
+static bool bch_alloc_sectors(struct data_insert_op *op,
+                              struct bkey *k, unsigned sectors)
 {
-        struct cache_set *c = s->c;
+        struct cache_set *c = op->c;
         struct open_bucket *b;
         BKEY_PADDED(key) alloc;
         unsigned i;
@@ -367,15 +366,15 @@ static bool bch_alloc_sectors(struct bkey *k, unsigned sectors,
         bkey_init(&alloc.key);
         spin_lock(&c->data_bucket_lock);
 
-        while (!(b = pick_data_bucket(c, k, s->task, &alloc.key))) {
-                unsigned watermark = s->write_prio
+        while (!(b = pick_data_bucket(c, k, op->task, &alloc.key))) {
+                unsigned watermark = op->write_prio
                         ? WATERMARK_MOVINGGC
                         : WATERMARK_NONE;
 
                 spin_unlock(&c->data_bucket_lock);
 
                 if (bch_bucket_alloc_set(c, watermark, &alloc.key,
-                                         1, s->writeback))
+                                         1, op->writeback))
                         return false;
 
                 spin_lock(&c->data_bucket_lock);
@@ -409,7 +408,7 @@ static bool bch_alloc_sectors(struct bkey *k, unsigned sectors,
          */
         list_move_tail(&b->list, &c->data_buckets);
         bkey_copy_key(&b->key, k);
-        b->last = s->task;
+        b->last = op->task;
 
         b->sectors_free -= sectors;
 
@@ -438,8 +437,8 @@ static bool bch_alloc_sectors(struct bkey *k, unsigned sectors,
 
 static void bch_data_invalidate(struct closure *cl)
 {
-        struct search *s = container_of(cl, struct search, btree);
-        struct bio *bio = s->cache_bio;
+        struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
+        struct bio *bio = op->bio;
 
         pr_debug("invalidating %i sectors from %llu",
                  bio_sectors(bio), (uint64_t) bio->bi_sector);
@@ -447,17 +446,17 @@ static void bch_data_invalidate(struct closure *cl)
         while (bio_sectors(bio)) {
                 unsigned len = min(bio_sectors(bio), 1U << 14);
 
-                if (bch_keylist_realloc(&s->insert_keys, 0, s->c))
+                if (bch_keylist_realloc(&op->insert_keys, 0, op->c))
                         goto out;
 
                 bio->bi_sector  += len;
                 bio->bi_size    -= len << 9;
 
-                bch_keylist_add(&s->insert_keys,
-                                &KEY(s->inode, bio->bi_sector, len));
+                bch_keylist_add(&op->insert_keys,
+                                &KEY(op->inode, bio->bi_sector, len));
         }
 
-        s->insert_data_done = true;
+        op->insert_data_done = true;
         bio_put(bio);
 out:
         continue_at(cl, bch_data_insert_keys, bcache_wq);
@@ -465,7 +464,7 @@ out:
 
 static void bch_data_insert_error(struct closure *cl)
 {
-        struct search *s = container_of(cl, struct search, btree);
+        struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
 
         /*
          * Our data write just errored, which means we've got a bunch of keys to
@@ -476,9 +475,9 @@ static void bch_data_insert_error(struct closure *cl)
          * from the keys we'll accomplish just that.
          */
 
-        struct bkey *src = s->insert_keys.keys, *dst = s->insert_keys.keys;
+        struct bkey *src = op->insert_keys.keys, *dst = op->insert_keys.keys;
 
-        while (src != s->insert_keys.top) {
+        while (src != op->insert_keys.top) {
                 struct bkey *n = bkey_next(src);
 
                 SET_KEY_PTRS(src, 0);
@@ -488,7 +487,7 @@ static void bch_data_insert_error(struct closure *cl)
                 src = n;
         }
 
-        s->insert_keys.top = dst;
+        op->insert_keys.top = dst;
 
         bch_data_insert_keys(cl);
 }
@@ -496,32 +495,32 @@ static void bch_data_insert_error(struct closure *cl)
 static void bch_data_insert_endio(struct bio *bio, int error)
 {
         struct closure *cl = bio->bi_private;
-        struct search *s = container_of(cl, struct search, btree);
+        struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
 
         if (error) {
                 /* TODO: We could try to recover from this. */
-                if (s->writeback)
-                        s->error = error;
-                else if (s->write)
+                if (op->writeback)
+                        op->error = error;
+                else if (!op->replace)
                         set_closure_fn(cl, bch_data_insert_error, bcache_wq);
                 else
                         set_closure_fn(cl, NULL, NULL);
         }
 
-        bch_bbio_endio(s->c, bio, error, "writing data to cache");
+        bch_bbio_endio(op->c, bio, error, "writing data to cache");
 }
 
 static void bch_data_insert_start(struct closure *cl)
 {
-        struct search *s = container_of(cl, struct search, btree);
-        struct bio *bio = s->cache_bio, *n;
+        struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
+        struct bio *bio = op->bio, *n;
 
-        if (s->bypass)
+        if (op->bypass)
                 return bch_data_invalidate(cl);
 
-        if (atomic_sub_return(bio_sectors(bio), &s->c->sectors_to_gc) < 0) {
-                set_gc_sectors(s->c);
-                wake_up_gc(s->c);
+        if (atomic_sub_return(bio_sectors(bio), &op->c->sectors_to_gc) < 0) {
+                set_gc_sectors(op->c);
+                wake_up_gc(op->c);
         }
 
         /*
@@ -533,21 +532,20 @@ static void bch_data_insert_start(struct closure *cl)
         do {
                 unsigned i;
                 struct bkey *k;
-                struct bio_set *split = s->d
-                        ? s->d->bio_split : s->c->bio_split;
+                struct bio_set *split = op->c->bio_split;
 
                 /* 1 for the device pointer and 1 for the chksum */
-                if (bch_keylist_realloc(&s->insert_keys,
-                                        1 + (s->csum ? 1 : 0),
-                                        s->c))
+                if (bch_keylist_realloc(&op->insert_keys,
+                                        1 + (op->csum ? 1 : 0),
+                                        op->c))
                         continue_at(cl, bch_data_insert_keys, bcache_wq);
 
-                k = s->insert_keys.top;
+                k = op->insert_keys.top;
                 bkey_init(k);
-                SET_KEY_INODE(k, s->inode);
+                SET_KEY_INODE(k, op->inode);
                 SET_KEY_OFFSET(k, bio->bi_sector);
 
-                if (!bch_alloc_sectors(k, bio_sectors(bio), s))
+                if (!bch_alloc_sectors(op, k, bio_sectors(bio)))
                         goto err;
 
                 n = bch_bio_split(bio, KEY_SIZE(k), GFP_NOIO, split);
@@ -555,30 +553,30 @@ static void bch_data_insert_start(struct closure *cl)
                 n->bi_end_io    = bch_data_insert_endio;
                 n->bi_private   = cl;
 
-                if (s->writeback) {
+                if (op->writeback) {
                         SET_KEY_DIRTY(k, true);
 
                         for (i = 0; i < KEY_PTRS(k); i++)
-                                SET_GC_MARK(PTR_BUCKET(s->c, k, i),
+                                SET_GC_MARK(PTR_BUCKET(op->c, k, i),
                                             GC_MARK_DIRTY);
                 }
 
-                SET_KEY_CSUM(k, s->csum);
+                SET_KEY_CSUM(k, op->csum);
                 if (KEY_CSUM(k))
                         bio_csum(n, k);
 
                 trace_bcache_cache_insert(k);
-                bch_keylist_push(&s->insert_keys);
+                bch_keylist_push(&op->insert_keys);
 
                 n->bi_rw |= REQ_WRITE;
-                bch_submit_bbio(n, s->c, k, 0);
+                bch_submit_bbio(n, op->c, k, 0);
         } while (n != bio);
 
-        s->insert_data_done = true;
+        op->insert_data_done = true;
         continue_at(cl, bch_data_insert_keys, bcache_wq);
 err:
         /* bch_alloc_sectors() blocks if s->writeback = true */
-        BUG_ON(s->writeback);
+        BUG_ON(op->writeback);
 
         /*
          * But if it's not a writeback write we'd rather just bail out if
@@ -586,24 +584,24 @@ err:
          * we might be starving btree writes for gc or something.
          */
 
-        if (s->write) {
+        if (!op->replace) {
                 /*
                  * Writethrough write: We can't complete the write until we've
                  * updated the index. But we don't want to delay the write while
                  * we wait for buckets to be freed up, so just invalidate the
                  * rest of the write.
                  */
-                s->bypass = true;
+                op->bypass = true;
                 return bch_data_invalidate(cl);
         } else {
                 /*
                  * From a cache miss, we can just insert the keys for the data
                  * we have written or bail out if we didn't do anything.
                  */
-                s->insert_data_done = true;
+                op->insert_data_done = true;
                 bio_put(bio);
 
-                if (!bch_keylist_empty(&s->insert_keys))
+                if (!bch_keylist_empty(&op->insert_keys))
                         continue_at(cl, bch_data_insert_keys, bcache_wq);
                 else
                         closure_return(cl);
@@ -631,15 +629,169 @@ err:
  */
 void bch_data_insert(struct closure *cl)
 {
-        struct search *s = container_of(cl, struct search, btree);
+        struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
 
-        bch_keylist_init(&s->insert_keys);
-        bio_get(s->cache_bio);
+        trace_bcache_write(op->bio, op->writeback, op->bypass);
+
+        bch_keylist_init(&op->insert_keys);
+        bio_get(op->bio);
         bch_data_insert_start(cl);
 }
 
+/* Congested? */
+
+unsigned bch_get_congested(struct cache_set *c)
+{
+        int i;
+        long rand;
+
+        if (!c->congested_read_threshold_us &&
+            !c->congested_write_threshold_us)
+                return 0;
+
+        i = (local_clock_us() - c->congested_last_us) / 1024;
+        if (i < 0)
+                return 0;
+
+        i += atomic_read(&c->congested);
+        if (i >= 0)
+                return 0;
+
+        i += CONGESTED_MAX;
+
+        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)
+{
+        ewma_add(t->sequential_io_avg,
+                 t->sequential_io, 8, 0);
+
+        t->sequential_io = 0;
+}
+
+static struct hlist_head *iohash(struct cached_dev *dc, uint64_t k)
+{
+        return &dc->io_hash[hash_64(k, RECENT_IO_BITS)];
+}
+
+static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
+{
+        struct cache_set *c = dc->disk.c;
+        unsigned mode = cache_mode(dc, bio);
+        unsigned sectors, congested = bch_get_congested(c);
+        struct task_struct *task = current;
+
+        if (atomic_read(&dc->disk.detaching) ||
+            c->gc_stats.in_use > CUTOFF_CACHE_ADD ||
+            (bio->bi_rw & REQ_DISCARD))
+                goto skip;
+
+        if (mode == CACHE_MODE_NONE ||
+            (mode == CACHE_MODE_WRITEAROUND &&
+             (bio->bi_rw & REQ_WRITE)))
+                goto skip;
+
+        if (bio->bi_sector & (c->sb.block_size - 1) ||
+            bio_sectors(bio) & (c->sb.block_size - 1)) {
+                pr_debug("skipping unaligned io");
+                goto skip;
+        }
+
+        if (!congested && !dc->sequential_cutoff)
+                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;
+
+                spin_lock(&dc->io_lock);
+
+                hlist_for_each_entry(i, iohash(dc, bio->bi_sector), hash)
+                        if (i->last == bio->bi_sector &&
+                            time_before(jiffies, i->jiffies))
+                                goto found;
+
+                i = list_first_entry(&dc->io_lru, struct io, lru);
+
+                add_sequential(task);
+                i->sequential = 0;
+found:
+                if (i->sequential + bio->bi_size > i->sequential)
+                        i->sequential   += bio->bi_size;
+
+                i->last                  = bio_end_sector(bio);
+                i->jiffies               = jiffies + msecs_to_jiffies(5000);
+                task->sequential_io      = i->sequential;
+
+                hlist_del(&i->hash);
+                hlist_add_head(&i->hash, iohash(dc, i->last));
+                list_move_tail(&i->lru, &dc->io_lru);
+
+                spin_unlock(&dc->io_lock);
+        } else {
+                task->sequential_io = bio->bi_size;
+
+                add_sequential(task);
+        }
+
+        sectors = max(task->sequential_io,
+                      task->sequential_io_avg) >> 9;
+
+        if (dc->sequential_cutoff &&
+            sectors >= dc->sequential_cutoff >> 9) {
+                trace_bcache_bypass_sequential(bio);
+                goto skip;
+        }
+
+        if (congested && sectors >= congested) {
+                trace_bcache_bypass_congested(bio);
+                goto skip;
+        }
+
+rescale:
+        bch_rescale_priorities(c, bio_sectors(bio));
+        return false;
+skip:
+        bch_mark_sectors_bypassed(c, dc, bio_sectors(bio));
+        return true;
+}
+
 /* Cache lookup */
 
+struct search {
+        /* Stack frame for bio_complete */
+        struct closure          cl;
+
+        struct bcache_device    *d;
+
+        struct bbio             bio;
+        struct bio              *orig_bio;
+        struct bio              *cache_miss;
+
+        unsigned                insert_bio_sectors;
+
+        unsigned                recoverable:1;
+        unsigned                unaligned_bvec:1;
+        unsigned                write:1;
+
+        unsigned long           start_time;
+
+        struct btree_op         op;
+        struct data_insert_op   iop;
+};
+
 static void bch_cache_read_endio(struct bio *bio, int error)
 {
         struct bbio *b = container_of(bio, struct bbio, bio);
@@ -654,13 +806,13 @@ static void bch_cache_read_endio(struct bio *bio, int error)
          */
 
         if (error)
-                s->error = error;
-        else if (ptr_stale(s->c, &b->key, 0)) {
-                atomic_long_inc(&s->c->cache_read_races);
-                s->error = -EINTR;
+                s->iop.error = error;
+        else if (ptr_stale(s->iop.c, &b->key, 0)) {
+                atomic_long_inc(&s->iop.c->cache_read_races);
+                s->iop.error = -EINTR;
         }
 
-        bch_bbio_endio(s->c, bio, error, "reading from cache");
+        bch_bbio_endio(s->iop.c, bio, error, "reading from cache");
 }
 
 /*
@@ -674,13 +826,13 @@ static int cache_lookup_fn(struct btree_op *op, struct btree *b, struct bkey *k)
         struct bkey *bio_key;
         unsigned ptr;
 
-        if (bkey_cmp(k, &KEY(s->inode, bio->bi_sector, 0)) <= 0)
+        if (bkey_cmp(k, &KEY(s->iop.inode, bio->bi_sector, 0)) <= 0)
                 return MAP_CONTINUE;
 
-        if (KEY_INODE(k) != s->inode ||
+        if (KEY_INODE(k) != s->iop.inode ||
             KEY_START(k) > bio->bi_sector) {
                 unsigned bio_sectors = bio_sectors(bio);
-                unsigned sectors = KEY_INODE(k) == s->inode
+                unsigned sectors = KEY_INODE(k) == s->iop.inode
                         ? min_t(uint64_t, INT_MAX,
                                 KEY_START(k) - bio->bi_sector)
                         : INT_MAX;
@@ -708,8 +860,8 @@ static int cache_lookup_fn(struct btree_op *op, struct btree *b, struct bkey *k)
         bio_key = &container_of(n, struct bbio, bio)->key;
         bch_bkey_copy_single_ptr(bio_key, k, ptr);
 
-        bch_cut_front(&KEY(s->inode, n->bi_sector, 0), bio_key);
-        bch_cut_back(&KEY(s->inode, bio_end_sector(n), 0), bio_key);
+        bch_cut_front(&KEY(s->iop.inode, n->bi_sector, 0), bio_key);
+        bch_cut_back(&KEY(s->iop.inode, bio_end_sector(n), 0), bio_key);
 
         n->bi_end_io    = bch_cache_read_endio;
         n->bi_private   = &s->cl;
@@ -731,11 +883,11 @@ static int cache_lookup_fn(struct btree_op *op, struct btree *b, struct bkey *k)
 
 static void cache_lookup(struct closure *cl)
 {
-        struct search *s = container_of(cl, struct search, btree);
+        struct search *s = container_of(cl, struct search, iop.cl);
         struct bio *bio = &s->bio.bio;
 
-        int ret = bch_btree_map_keys(&s->op, s->c,
-                                     &KEY(s->inode, bio->bi_sector, 0),
+        int ret = bch_btree_map_keys(&s->op, s->iop.c,
+                                     &KEY(s->iop.inode, bio->bi_sector, 0),
                                      cache_lookup_fn, MAP_END_KEY);
         if (ret == -EAGAIN)
                 continue_at(cl, cache_lookup, bcache_wq);
@@ -751,7 +903,7 @@ static void request_endio(struct bio *bio, int error)
 
         if (error) {
                 struct search *s = container_of(cl, struct search, cl);
-                s->error = error;
+                s->iop.error = error;
                 /* Only cache read errors are recoverable */
                 s->recoverable = false;
         }
@@ -771,8 +923,8 @@ static void bio_complete(struct search *s)
                 part_stat_add(cpu, &s->d->disk->part0, ticks[rw], duration);
                 part_stat_unlock();
 
-                trace_bcache_request_end(s, s->orig_bio);
-                bio_endio(s->orig_bio, s->error);
+                trace_bcache_request_end(s->d, s->orig_bio);
+                bio_endio(s->orig_bio, s->iop.error);
                 s->orig_bio = NULL;
         }
 }
@@ -792,8 +944,8 @@ static void search_free(struct closure *cl)
         struct search *s = container_of(cl, struct search, cl);
         bio_complete(s);
 
-        if (s->cache_bio)
-                bio_put(s->cache_bio);
+        if (s->iop.bio)
+                bio_put(s->iop.bio);
 
         if (s->unaligned_bvec)
                 mempool_free(s->bio.bio.bi_io_vec, s->d->unaligned_bvec);
@@ -808,18 +960,18 @@ static struct search *search_alloc(struct bio *bio, struct bcache_device *d)
         struct bio_vec *bv;
 
         s = mempool_alloc(d->c->search, GFP_NOIO);
-        memset(s, 0, offsetof(struct search, insert_keys));
+        memset(s, 0, offsetof(struct search, iop.insert_keys));
 
         __closure_init(&s->cl, NULL);
 
-        s->inode                = d->id;
-        s->c                    = d->c;
+        s->iop.inode            = d->id;
+        s->iop.c                = d->c;
         s->d                    = d;
         s->op.lock              = -1;
-        s->task                 = current;
+        s->iop.task             = current;
         s->orig_bio             = bio;
         s->write                = (bio->bi_rw & REQ_WRITE) != 0;
-        s->flush_journal        = (bio->bi_rw & (REQ_FLUSH|REQ_FUA)) != 0;
+        s->iop.flush_journal    = (bio->bi_rw & (REQ_FLUSH|REQ_FUA)) != 0;
         s->recoverable          = 1;
         s->start_time           = jiffies;
         do_bio_hook(s);
@@ -847,148 +999,20 @@ static void cached_dev_bio_complete(struct closure *cl)
         cached_dev_put(dc);
 }
 
-unsigned bch_get_congested(struct cache_set *c)
-{
-        int i;
-        long rand;
-
-        if (!c->congested_read_threshold_us &&
-            !c->congested_write_threshold_us)
-                return 0;
-
-        i = (local_clock_us() - c->congested_last_us) / 1024;
-        if (i < 0)
-                return 0;
-
-        i += atomic_read(&c->congested);
-        if (i >= 0)
-                return 0;
-
-        i += CONGESTED_MAX;
-
-        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)
-{
-        ewma_add(t->sequential_io_avg,
-                 t->sequential_io, 8, 0);
-
-        t->sequential_io = 0;
-}
-
-static struct hlist_head *iohash(struct cached_dev *dc, uint64_t k)
-{
-        return &dc->io_hash[hash_64(k, RECENT_IO_BITS)];
-}
-
-static bool check_should_bypass(struct cached_dev *dc, struct search *s)
-{
-        struct cache_set *c = s->c;
-        struct bio *bio = &s->bio.bio;
-        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 ||
-            (bio->bi_rw & REQ_DISCARD))
-                goto skip;
-
-        if (mode == CACHE_MODE_NONE ||
-            (mode == CACHE_MODE_WRITEAROUND &&
-             (bio->bi_rw & REQ_WRITE)))
-                goto skip;
-
-        if (bio->bi_sector & (c->sb.block_size - 1) ||
-            bio_sectors(bio) & (c->sb.block_size - 1)) {
-                pr_debug("skipping unaligned io");
-                goto skip;
-        }
-
-        if (!congested && !dc->sequential_cutoff)
-                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;
-
-                spin_lock(&dc->io_lock);
-
-                hlist_for_each_entry(i, iohash(dc, bio->bi_sector), hash)
-                        if (i->last == bio->bi_sector &&
-                            time_before(jiffies, i->jiffies))
-                                goto found;
-
-                i = list_first_entry(&dc->io_lru, struct io, lru);
-
-                add_sequential(s->task);
-                i->sequential = 0;
-found:
-                if (i->sequential + bio->bi_size > i->sequential)
-                        i->sequential   += bio->bi_size;
-
-                i->last                  = bio_end_sector(bio);
-                i->jiffies               = jiffies + msecs_to_jiffies(5000);
-                s->task->sequential_io   = i->sequential;
-
-                hlist_del(&i->hash);
-                hlist_add_head(&i->hash, iohash(dc, i->last));
-                list_move_tail(&i->lru, &dc->io_lru);
-
-                spin_unlock(&dc->io_lock);
-        } else {
-                s->task->sequential_io = bio->bi_size;
-
-                add_sequential(s->task);
-        }
-
-        sectors = 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));
-        return false;
-skip:
-        bch_mark_sectors_bypassed(s, bio_sectors(bio));
-        return true;
-}
-
 /* Process reads */
 
 static void cached_dev_cache_miss_done(struct closure *cl)
 {
         struct search *s = container_of(cl, struct search, cl);
 
-        if (s->insert_collision)
-                bch_mark_cache_miss_collision(s);
+        if (s->iop.replace_collision)
+                bch_mark_cache_miss_collision(s->iop.c, s->d);
 
-        if (s->cache_bio) {
+        if (s->iop.bio) {
                 int i;
                 struct bio_vec *bv;
 
-                bio_for_each_segment_all(bv, s->cache_bio, i)
+                bio_for_each_segment_all(bv, s->iop.bio, i)
                         __free_page(bv->bv_page);
         }
 
@@ -1006,7 +1030,7 @@ static void cached_dev_read_error(struct closure *cl)
                 /* Retry from the backing device: */
                 trace_bcache_read_retry(s->orig_bio);
 
-                s->error = 0;
+                s->iop.error = 0;
                 bv = s->bio.bio.bi_io_vec;
                 do_bio_hook(s);
                 s->bio.bio.bi_io_vec = bv;
@@ -1041,29 +1065,28 @@ static void cached_dev_read_done(struct closure *cl)
          * to the buffers the original bio pointed to:
          */
 
-        if (s->cache_bio) {
-                bio_reset(s->cache_bio);
-                s->cache_bio->bi_sector =
-                        s->cache_miss->bi_sector;
-                s->cache_bio->bi_bdev = s->cache_miss->bi_bdev;
-                s->cache_bio->bi_size = s->cache_bio_sectors << 9;
-                bch_bio_map(s->cache_bio, NULL);
+        if (s->iop.bio) {
+                bio_reset(s->iop.bio);
+                s->iop.bio->bi_sector = s->cache_miss->bi_sector;
+                s->iop.bio->bi_bdev = s->cache_miss->bi_bdev;
+                s->iop.bio->bi_size = s->insert_bio_sectors << 9;
+                bch_bio_map(s->iop.bio, NULL);
 
-                bio_copy_data(s->cache_miss, s->cache_bio);
+                bio_copy_data(s->cache_miss, s->iop.bio);
 
                 bio_put(s->cache_miss);
                 s->cache_miss = NULL;
         }
 
-        if (verify(dc, &s->bio.bio) && s->recoverable)
-                bch_data_verify(s);
+        if (verify(dc, &s->bio.bio) && s->recoverable && !s->unaligned_bvec)
+                bch_data_verify(dc, s->orig_bio);
 
         bio_complete(s);
 
-        if (s->cache_bio &&
-            !test_bit(CACHE_SET_STOPPING, &s->c->flags)) {
-                BUG_ON(!s->replace);
-                closure_call(&s->btree, bch_data_insert, NULL, cl);
+        if (s->iop.bio &&
+            !test_bit(CACHE_SET_STOPPING, &s->iop.c->flags)) {
+                BUG_ON(!s->iop.replace);
+                closure_call(&s->iop.cl, bch_data_insert, NULL, cl);
         }
 
         continue_at(cl, cached_dev_cache_miss_done, NULL);
@@ -1074,12 +1097,13 @@ static void cached_dev_read_done_bh(struct closure *cl)
         struct search *s = container_of(cl, struct search, cl);
         struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
 
-        bch_mark_cache_accounting(s, !s->cache_miss, s->bypass);
-        trace_bcache_read(s->orig_bio, !s->cache_miss, s->bypass);
+        bch_mark_cache_accounting(s->iop.c, s->d,
+                                  !s->cache_miss, s->iop.bypass);
+        trace_bcache_read(s->orig_bio, !s->cache_miss, s->iop.bypass);
 
-        if (s->error)
+        if (s->iop.error)
                 continue_at_nobarrier(cl, cached_dev_read_error, bcache_wq);
-        else if (s->cache_bio || verify(dc, &s->bio.bio))
+        else if (s->iop.bio || verify(dc, &s->bio.bio))
                 continue_at_nobarrier(cl, cached_dev_read_done, bcache_wq);
         else
                 continue_at_nobarrier(cl, cached_dev_bio_complete, NULL);
@@ -1093,7 +1117,7 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
         struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
         struct bio *miss, *cache_bio;
 
-        if (s->cache_miss || s->bypass) {
+        if (s->cache_miss || s->iop.bypass) {
                 miss = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split);
                 ret = miss == bio ? MAP_DONE : MAP_CONTINUE;
                 goto out_submit;
@@ -1101,20 +1125,21 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
 
         if (!(bio->bi_rw & REQ_RAHEAD) &&
             !(bio->bi_rw & REQ_META) &&
-            s->c->gc_stats.in_use < CUTOFF_CACHE_READA)
+            s->iop.c->gc_stats.in_use < CUTOFF_CACHE_READA)
                 reada = min_t(sector_t, dc->readahead >> 9,
                               bdev_sectors(bio->bi_bdev) - bio_end_sector(bio));
 
-        s->cache_bio_sectors = min(sectors, bio_sectors(bio) + reada);
+        s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);
 
-        s->replace_key = KEY(s->inode, bio->bi_sector +
-                             s->cache_bio_sectors, s->cache_bio_sectors);
+        s->iop.replace_key = KEY(s->iop.inode,
+                                 bio->bi_sector + s->insert_bio_sectors,
+                                 s->insert_bio_sectors);
 
-        ret = bch_btree_insert_check_key(b, &s->op, &s->replace_key);
+        ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);
         if (ret)
                 return ret;
 
-        s->replace = true;
+        s->iop.replace = true;
 
         miss = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split);
 
@@ -1122,14 +1147,14 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
         ret = miss == bio ? MAP_DONE : -EINTR;
 
         cache_bio = bio_alloc_bioset(GFP_NOWAIT,
-                        DIV_ROUND_UP(s->cache_bio_sectors, PAGE_SECTORS),
+                        DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
                         dc->disk.bio_split);
         if (!cache_bio)
                 goto out_submit;
 
         cache_bio->bi_sector    = miss->bi_sector;
         cache_bio->bi_bdev      = miss->bi_bdev;
-        cache_bio->bi_size      = s->cache_bio_sectors << 9;
+        cache_bio->bi_size      = s->insert_bio_sectors << 9;
 
         cache_bio->bi_end_io    = request_endio;
         cache_bio->bi_private   = &s->cl;
@@ -1138,8 +1163,11 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
         if (bio_alloc_pages(cache_bio, __GFP_NOWARN|GFP_NOIO))
                 goto out_put;
 
+        if (reada)
+                bch_mark_cache_readahead(s->iop.c, s->d);
+
         s->cache_miss   = miss;
-        s->cache_bio = cache_bio;
+        s->iop.bio      = cache_bio;
         bio_get(cache_bio);
         closure_bio_submit(cache_bio, &s->cl, s->d);
 
@@ -1157,7 +1185,7 @@ static void cached_dev_read(struct cached_dev *dc, struct search *s)
 {
         struct closure *cl = &s->cl;
 
-        closure_call(&s->btree, cache_lookup, NULL, cl);
+        closure_call(&s->iop.cl, cache_lookup, NULL, cl);
         continue_at(cl, cached_dev_read_done_bh, NULL);
 }
 
@@ -1179,7 +1207,7 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s)
         struct bkey start = KEY(dc->disk.id, bio->bi_sector, 0);
         struct bkey end = KEY(dc->disk.id, bio_end_sector(bio), 0);
 
-        bch_keybuf_check_overlapping(&s->c->moving_gc_keys, &start, &end);
+        bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys, &start, &end);
 
         down_read_non_owner(&dc->writeback_lock);
         if (bch_keybuf_check_overlapping(&dc->writeback_keys, &start, &end)) {
@@ -1187,8 +1215,8 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s)
                  * We overlap with some dirty data undergoing background
                  * writeback, force this write to writeback
                  */
-                s->bypass       = false;
-                s->writeback    = true;
+                s->iop.bypass = false;
+                s->iop.writeback = true;
         }
 
         /*
@@ -1199,27 +1227,25 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s)
          * so we still want to call it.
          */
         if (bio->bi_rw & REQ_DISCARD)
-                s->bypass = true;
+                s->iop.bypass = true;
 
         if (should_writeback(dc, s->orig_bio,
                              cache_mode(dc, bio),
-                             s->bypass)) {
-                s->bypass = false;
-                s->writeback = true;
+                             s->iop.bypass)) {
+                s->iop.bypass = false;
+                s->iop.writeback = true;
         }
 
-        trace_bcache_write(s->orig_bio, s->writeback, s->bypass);
-
-        if (s->bypass) {
-                s->cache_bio = s->orig_bio;
-                bio_get(s->cache_bio);
+        if (s->iop.bypass) {
+                s->iop.bio = s->orig_bio;
+                bio_get(s->iop.bio);
 
                 if (!(bio->bi_rw & REQ_DISCARD) ||
                     blk_queue_discard(bdev_get_queue(dc->bdev)))
                         closure_bio_submit(bio, cl, s->d);
-        } else if (s->writeback) {
+        } else if (s->iop.writeback) {
                 bch_writeback_add(dc);
-                s->cache_bio = bio;
+                s->iop.bio = bio;
 
                 if (bio->bi_rw & REQ_FLUSH) {
                         /* Also need to send a flush to the backing device */
@@ -1234,13 +1260,13 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s)
                         closure_bio_submit(flush, cl, s->d);
                 }
         } else {
-                s->cache_bio = bio_clone_bioset(bio, GFP_NOIO,
-                                                dc->disk.bio_split);
+                s->iop.bio = bio_clone_bioset(bio, GFP_NOIO,
+                                              dc->disk.bio_split);
 
                 closure_bio_submit(bio, cl, s->d);
         }
 
-        closure_call(&s->btree, bch_data_insert, NULL, cl);
+        closure_call(&s->iop.cl, bch_data_insert, NULL, cl);
         continue_at(cl, cached_dev_write_complete, NULL);
 }
 
@@ -1249,8 +1275,8 @@ static void cached_dev_nodata(struct closure *cl)
         struct search *s = container_of(cl, struct search, cl);
         struct bio *bio = &s->bio.bio;
 
-        if (s->flush_journal)
-                bch_journal_meta(s->c, cl);
+        if (s->iop.flush_journal)
+                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);
@@ -1277,7 +1303,7 @@ static void cached_dev_make_request(struct request_queue *q, struct bio *bio)
 
         if (cached_dev_get(dc)) {
                 s = search_alloc(bio, d);
-                trace_bcache_request_start(s, bio);
+                trace_bcache_request_start(s->d, bio);
 
                 if (!bio->bi_size) {
                         /*
@@ -1288,7 +1314,7 @@ static void cached_dev_make_request(struct request_queue *q, struct bio *bio)
                                               cached_dev_nodata,
                                               bcache_wq);
                 } else {
-                        s->bypass = check_should_bypass(dc, s);
+                        s->iop.bypass = check_should_bypass(dc, bio);
 
                         if (rw)
                                 cached_dev_write(dc, s);
@@ -1378,8 +1404,8 @@ static void flash_dev_nodata(struct closure *cl)
 {
         struct search *s = container_of(cl, struct search, cl);
 
-        if (s->flush_journal)
-                bch_journal_meta(s->c, cl);
+        if (s->iop.flush_journal)
+                bch_journal_meta(s->iop.c, cl);
 
         continue_at(cl, search_free, NULL);
 }
@@ -1400,7 +1426,7 @@ static void flash_dev_make_request(struct request_queue *q, struct bio *bio)
         cl = &s->cl;
         bio = &s->bio.bio;
 
-        trace_bcache_request_start(s, bio);
+        trace_bcache_request_start(s->d, bio);
 
         if (!bio->bi_size) {
                 /*
@@ -1411,17 +1437,17 @@ static void flash_dev_make_request(struct request_queue *q, struct bio *bio)
                                       flash_dev_nodata,
                                       bcache_wq);
         } else if (rw) {
-                bch_keybuf_check_overlapping(&s->c->moving_gc_keys,
+                bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys,
                                         &KEY(d->id, bio->bi_sector, 0),
                                         &KEY(d->id, bio_end_sector(bio), 0));
 
-                s->bypass       = (bio->bi_rw & REQ_DISCARD) != 0;
-                s->writeback    = true;
-                s->cache_bio    = bio;
+                s->iop.bypass           = (bio->bi_rw & REQ_DISCARD) != 0;
+                s->iop.writeback        = true;
+                s->iop.bio              = bio;
 
-                closure_call(&s->btree, bch_data_insert, NULL, cl);
+                closure_call(&s->iop.cl, bch_data_insert, NULL, cl);
         } else {
-                closure_call(&s->btree, cache_lookup, NULL, cl);
+                closure_call(&s->iop.cl, cache_lookup, NULL, cl);
         }
 
         continue_at(cl, search_free, NULL);