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authorKent Overstreet <kent.overstreet@gmail.com>2017-03-19 15:56:34 -0800
committerKent Overstreet <kent.overstreet@gmail.com>2017-03-19 17:31:47 -0800
commit5ec39af8eaba49aee7bafa44c661da39e2f40dc3 (patch)
tree1fb1a981602cbf22c7d2b2dba1168c715d7cecb5 /libbcache/request.c
parentbb1941de5378a7b8122d3575dcbc7d0aeb6326f0 (diff)
Rename from bcache-tools to bcachefs-tools
Diffstat (limited to 'libbcache/request.c')
-rw-r--r--libbcache/request.c809
1 files changed, 0 insertions, 809 deletions
diff --git a/libbcache/request.c b/libbcache/request.c
deleted file mode 100644
index b24770bc..00000000
--- a/libbcache/request.c
+++ /dev/null
@@ -1,809 +0,0 @@
-/*
- * Handle a read or a write request and decide what to do with it.
- *
- * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
- * Copyright 2012 Google, Inc.
- *
- * Main pieces here:
- *
- * 1) Data insert path, via bch_data_insert() -- writes data to cache and
- * updates extents btree
- * 2) Read path, via bch_read() -- for now only used by bcachefs and ioctl
- * interface
- * 3) Read path, via cache_lookup() and struct search -- used by block device
- * make_request functions
- * 4) Cache promotion -- used by bch_read() and cache_lookup() to copy data to
- * the cache, either from a backing device or a cache device in a higher tier
- *
- * One tricky thing that comes up is a race condition where a bucket may be
- * re-used while reads from it are still in flight. To guard against this, we
- * save the ptr that is being read and check if it is stale once the read
- * completes. If the ptr is stale, the read is retried.
- *
- * #2 and #3 will be unified further in the future.
- */
-
-#include "bcache.h"
-#include "blockdev.h"
-#include "btree_update.h"
-#include "btree_iter.h"
-#include "clock.h"
-#include "debug.h"
-#include "error.h"
-#include "extents.h"
-#include "io.h"
-#include "journal.h"
-#include "keybuf.h"
-#include "request.h"
-#include "writeback.h"
-#include "stats.h"
-
-#include <linux/module.h>
-#include <linux/hash.h>
-#include <linux/random.h>
-#include <linux/backing-dev.h>
-
-#include <trace/events/bcache.h>
-
-#define CUTOFF_CACHE_ADD 10
-#define CUTOFF_CACHE_READA 15
-
-/* Congested? */
-
-unsigned bch_get_congested(struct bch_fs *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)
-{
- t->sequential_io_avg = ewma_add(t->sequential_io_avg,
- t->sequential_io, 3);
- 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, int rw)
-{
- struct bch_fs *c = dc->disk.c;
- unsigned mode = BDEV_CACHE_MODE(dc->disk_sb.sb);
- unsigned sectors, congested = bch_get_congested(c);
- struct task_struct *task = current;
- struct io *i;
-
- if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
- sectors_available(c) * 100 < c->capacity * CUTOFF_CACHE_ADD ||
- (bio_op(bio) == REQ_OP_DISCARD))
- goto skip;
-
- if (mode == CACHE_MODE_NONE ||
- (mode == CACHE_MODE_WRITEAROUND &&
- op_is_write(bio_op(bio))))
- goto skip;
-
- if (bio->bi_iter.bi_sector & (c->sb.block_size - 1) ||
- bio_sectors(bio) & (c->sb.block_size - 1)) {
- pr_debug("skipping unaligned io");
- goto skip;
- }
-
- if (bypass_torture_test(dc)) {
- if ((get_random_int() & 3) == 3)
- goto skip;
- else
- goto rescale;
- }
-
- if (!congested && !dc->sequential_cutoff)
- goto rescale;
-
- if (!congested &&
- mode == CACHE_MODE_WRITEBACK &&
- op_is_write(bio_op(bio)) &&
- (bio->bi_opf & REQ_SYNC))
- goto rescale;
-
- spin_lock(&dc->io_lock);
-
- hlist_for_each_entry(i, iohash(dc, bio->bi_iter.bi_sector), hash)
- if (i->last == bio->bi_iter.bi_sector &&
- time_before(jiffies, i->last_io))
- goto found;
-
- i = list_first_entry(&dc->io_lru, struct io, lru);
-
- add_sequential(task);
- i->sequential = 0;
-found:
- if (i->sequential + bio->bi_iter.bi_size > i->sequential)
- i->sequential += bio->bi_iter.bi_size;
-
- i->last = bio_end_sector(bio);
- i->last_io = 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);
-
- 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:
- return false;
-skip:
- bch_mark_sectors_bypassed(c, dc, bio_sectors(bio));
- return true;
-}
-
-/* Common code for the make_request functions */
-
-/**
- * request_endio - endio function for backing device bios
- */
-static void request_endio(struct bio *bio)
-{
- struct closure *cl = bio->bi_private;
-
- if (bio->bi_error) {
- struct search *s = container_of(cl, struct search, cl);
- s->iop.error = bio->bi_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) {
- generic_end_io_acct(bio_data_dir(s->orig_bio),
- &s->d->disk->part0, s->start_time);
-
- trace_bcache_request_end(s->d, s->orig_bio);
- s->orig_bio->bi_error = s->iop.error;
- bio_endio(s->orig_bio);
- s->orig_bio = NULL;
- }
-}
-
-static void do_bio_hook(struct search *s, struct bio *orig_bio)
-{
- int rw = bio_data_dir(orig_bio);
- struct bio *bio = rw ? &s->wbio.bio : &s->rbio.bio;
-
- bio_init(bio);
- __bio_clone_fast(bio, orig_bio);
- bio->bi_end_io = request_endio;
- bio->bi_private = &s->cl;
-
- bio_cnt_set(bio, 3);
-}
-
-static void search_free(struct closure *cl)
-{
- struct search *s = container_of(cl, struct search, cl);
-
- bio_complete(s);
-
- if (s->iop.bio)
- bio_put(&s->iop.bio->bio);
-
- closure_debug_destroy(cl);
- mempool_free(s, &s->d->c->search);
-}
-
-static inline struct search *search_alloc(struct bio *bio,
- struct bcache_device *d)
-{
- struct search *s;
-
- s = mempool_alloc(&d->c->search, GFP_NOIO);
-
- closure_init(&s->cl, NULL);
- do_bio_hook(s, bio);
-
- s->orig_bio = bio;
- s->d = d;
- s->recoverable = 1;
- s->bypass = 0;
- s->write = op_is_write(bio_op(bio));
- s->read_dirty_data = 0;
- s->cache_miss = 0;
- s->start_time = jiffies;
- s->inode = bcache_dev_inum(d);
-
- s->iop.c = d->c;
- s->iop.bio = NULL;
- s->iop.error = 0;
-
- return s;
-}
-
-/* Cached devices */
-
-static void cached_dev_bio_complete(struct closure *cl)
-{
- struct search *s = container_of(cl, struct search, cl);
- struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
-
- search_free(cl);
- cached_dev_put(dc);
-}
-
-/* Process reads */
-
-static void cached_dev_read_error(struct closure *cl)
-{
- struct search *s = container_of(cl, struct search, cl);
- struct bio *bio = &s->rbio.bio;
-
- if (s->recoverable) {
- /* Read bucket invalidate races are handled here, also plain
- * old IO errors from the cache that can be retried from the
- * backing device (reads of clean data) */
- trace_bcache_read_retry(s->orig_bio);
-
- s->iop.error = 0;
- do_bio_hook(s, s->orig_bio);
-
- /* XXX: invalidate cache, don't count twice */
-
- closure_bio_submit(bio, cl);
- }
-
- continue_at(cl, cached_dev_bio_complete, NULL);
-}
-
-static void cached_dev_read_done(struct closure *cl)
-{
- struct search *s = container_of(cl, struct search, cl);
- struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
-
- if (dc->verify && s->recoverable && !s->read_dirty_data)
- bch_data_verify(dc, s->orig_bio);
-
- continue_at_nobarrier(cl, cached_dev_bio_complete, NULL);
-}
-
-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->iop.c, dc, !s->cache_miss, s->bypass);
- trace_bcache_read(s->orig_bio, !s->cache_miss, s->bypass);
-
- if (s->iop.error)
- continue_at_nobarrier(cl, cached_dev_read_error, s->iop.c->wq);
- else if (dc->verify)
- continue_at_nobarrier(cl, cached_dev_read_done, s->iop.c->wq);
- else
- continue_at_nobarrier(cl, cached_dev_bio_complete, NULL);
-}
-
-/**
- * __cache_promote -- insert result of read bio into cache
- *
- * Used for backing devices and flash-only volumes.
- *
- * @orig_bio must actually be a bbio with a valid key.
- */
-void __cache_promote(struct bch_fs *c, struct bch_read_bio *orig_bio,
- struct bkey_s_c old,
- struct bkey_s_c new,
- unsigned write_flags)
-{
-#if 0
- struct cache_promote_op *op;
- struct bio *bio;
- unsigned pages = DIV_ROUND_UP(orig_bio->bio.bi_iter.bi_size, PAGE_SIZE);
-
- /* XXX: readahead? */
-
- op = kmalloc(sizeof(*op) + sizeof(struct bio_vec) * pages, GFP_NOIO);
- if (!op)
- goto out_submit;
-
- /* clone the bbio */
- memcpy(&op->bio, orig_bio, offsetof(struct bbio, bio));
-
- bio = &op->bio.bio.bio;
- bio_init(bio);
- bio_get(bio);
- bio->bi_bdev = orig_bio->bio.bi_bdev;
- bio->bi_iter.bi_sector = orig_bio->bio.bi_iter.bi_sector;
- bio->bi_iter.bi_size = orig_bio->bio.bi_iter.bi_size;
- bio->bi_end_io = cache_promote_endio;
- bio->bi_private = &op->cl;
- bio->bi_io_vec = bio->bi_inline_vecs;
- bch_bio_map(bio, NULL);
-
- if (bio_alloc_pages(bio, __GFP_NOWARN|GFP_NOIO))
- goto out_free;
-
- orig_bio->ca = NULL;
-
- closure_init(&op->cl, &c->cl);
- op->orig_bio = &orig_bio->bio;
- op->stale = 0;
-
- bch_write_op_init(&op->iop, c, &op->bio, &c->promote_write_point,
- new, old,
- BCH_WRITE_ALLOC_NOWAIT|write_flags);
- op->iop.nr_replicas = 1;
-
- //bch_cut_front(bkey_start_pos(&orig_bio->key.k), &op->iop.insert_key);
- //bch_cut_back(orig_bio->key.k.p, &op->iop.insert_key.k);
-
- trace_bcache_promote(&orig_bio->bio);
-
- op->bio.bio.submit_time_us = local_clock_us();
- closure_bio_submit(bio, &op->cl);
-
- continue_at(&op->cl, cache_promote_write, c->wq);
-out_free:
- kfree(op);
-out_submit:
- generic_make_request(&orig_bio->bio);
-#endif
-}
-
-/**
- * cached_dev_cache_miss - populate cache with data from backing device
- *
- * We don't write to the cache if s->bypass is set.
- */
-static int cached_dev_cache_miss(struct btree_iter *iter, struct search *s,
- struct bio *bio, unsigned sectors)
-{
- int ret;
- unsigned reada = 0;
- struct bio *miss;
- BKEY_PADDED(key) replace;
-
- s->cache_miss = 1;
-
- if (s->bypass)
- goto nopromote;
-#if 0
- struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
-
- /* XXX: broken */
- if (!(bio->bi_opf & REQ_RAHEAD) &&
- !(bio->bi_opf & REQ_META) &&
- ((u64) sectors_available(dc->disk.c) * 100 <
- (u64) iter->c->capacity * CUTOFF_CACHE_READA))
- reada = min_t(sector_t, dc->readahead >> 9,
- bdev_sectors(bio->bi_bdev) - bio_end_sector(bio));
-#endif
- sectors = min(sectors, bio_sectors(bio) + reada);
-
- replace.key.k = KEY(s->inode,
- bio->bi_iter.bi_sector + sectors,
- sectors);
-
- ret = bch_btree_insert_check_key(iter, &replace.key);
- if (ret == -EINTR)
- return ret;
-
- miss = bio_next_split(bio, sectors, GFP_NOIO, &s->d->bio_split);
-
- miss->bi_end_io = request_endio;
- miss->bi_private = &s->cl;
-
- //to_bbio(miss)->key.k = KEY(s->inode,
- // bio_end_sector(miss),
- // bio_sectors(miss));
- to_rbio(miss)->ca = NULL;
-
- closure_get(&s->cl);
- __cache_promote(s->iop.c, to_rbio(miss),
- bkey_i_to_s_c(&replace.key),
- bkey_to_s_c(&KEY(replace.key.k.p.inode,
- replace.key.k.p.offset,
- replace.key.k.size)),
- BCH_WRITE_CACHED);
-
- return 0;
-nopromote:
- miss = bio_next_split(bio, sectors, GFP_NOIO, &s->d->bio_split);
-
- miss->bi_end_io = request_endio;
- miss->bi_private = &s->cl;
- closure_bio_submit(miss, &s->cl);
-
- return 0;
-}
-
-static void cached_dev_read(struct cached_dev *dc, struct search *s)
-{
- struct bch_fs *c = s->iop.c;
- struct closure *cl = &s->cl;
- struct bio *bio = &s->rbio.bio;
- struct btree_iter iter;
- struct bkey_s_c k;
- int ret;
-
- bch_increment_clock(c, bio_sectors(bio), READ);
-
- for_each_btree_key_with_holes(&iter, c, BTREE_ID_EXTENTS,
- POS(s->inode, bio->bi_iter.bi_sector), k) {
- BKEY_PADDED(k) tmp;
- struct extent_pick_ptr pick;
- unsigned sectors, bytes;
- bool is_last;
-retry:
- bkey_reassemble(&tmp.k, k);
- bch_btree_iter_unlock(&iter);
- k = bkey_i_to_s_c(&tmp.k);
-
- bch_extent_pick_ptr(c, k, &pick);
- if (IS_ERR(pick.ca)) {
- bcache_io_error(c, bio, "no device to read from");
- goto out;
- }
-
- sectors = min_t(u64, k.k->p.offset, bio_end_sector(bio)) -
- bio->bi_iter.bi_sector;
- bytes = sectors << 9;
- is_last = bytes == bio->bi_iter.bi_size;
- swap(bio->bi_iter.bi_size, bytes);
-
- if (pick.ca) {
- PTR_BUCKET(pick.ca, &pick.ptr)->read_prio =
- c->prio_clock[READ].hand;
-
- if (!bkey_extent_is_cached(k.k))
- s->read_dirty_data = true;
-
- bch_read_extent(c, &s->rbio, k, &pick,
- BCH_READ_ACCOUNT_TIMES|
- BCH_READ_RETRY_IF_STALE|
- (!s->bypass ? BCH_READ_PROMOTE : 0)|
- (is_last ? BCH_READ_IS_LAST : 0));
- } else {
- /* not present (hole), or stale cached data */
- if (cached_dev_cache_miss(&iter, s, bio, sectors)) {
- k = bch_btree_iter_peek_with_holes(&iter);
- if (btree_iter_err(k))
- break;
- goto retry;
- }
- }
-
- swap(bio->bi_iter.bi_size, bytes);
- bio_advance(bio, bytes);
-
- if (is_last) {
- bch_btree_iter_unlock(&iter);
- goto out;
- }
- }
-
- /*
- * If we get here, it better have been because there was an error
- * reading a btree node
- */
- ret = bch_btree_iter_unlock(&iter);
- BUG_ON(!ret);
- bcache_io_error(c, bio, "btree IO error %i", ret);
-out:
- continue_at(cl, cached_dev_read_done_bh, NULL);
-}
-
-/* Process writes */
-
-static void cached_dev_write_complete(struct closure *cl)
-{
- struct search *s = container_of(cl, struct search, cl);
- struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
-
- up_read_non_owner(&dc->writeback_lock);
- cached_dev_bio_complete(cl);
-}
-
-static void cached_dev_write(struct cached_dev *dc, struct search *s)
-{
- struct closure *cl = &s->cl;
- struct bio *bio = &s->wbio.bio;
- bool writeback = false;
- bool bypass = s->bypass;
- struct bkey insert_key = KEY(s->inode,
- bio_end_sector(bio),
- bio_sectors(bio));
- unsigned flags = BCH_WRITE_DISCARD_ON_ERROR;
-
- down_read_non_owner(&dc->writeback_lock);
- if (bch_keybuf_check_overlapping(&dc->writeback_keys,
- bkey_start_pos(&insert_key),
- insert_key.p)) {
- /*
- * We overlap with some dirty data undergoing background
- * writeback, force this write to writeback
- */
- bypass = false;
- writeback = true;
- }
-
- /*
- * Discards aren't _required_ to do anything, so skipping if
- * check_overlapping returned true is ok
- *
- * But check_overlapping drops dirty keys for which io hasn't started,
- * so we still want to call it.
- */
- if (bio_op(bio) == REQ_OP_DISCARD)
- bypass = true;
-
- if (should_writeback(dc, bio, BDEV_CACHE_MODE(dc->disk_sb.sb),
- bypass)) {
- bypass = false;
- writeback = true;
- }
-
- if (bypass) {
- /*
- * If this is a bypass-write (as opposed to a discard), send
- * it down to the backing device. If this is a discard, only
- * send it to the backing device if the backing device
- * supports discards. Otherwise, we simply discard the key
- * range from the cache and don't touch the backing device.
- */
- if ((bio_op(bio) != REQ_OP_DISCARD) ||
- blk_queue_discard(bdev_get_queue(dc->disk_sb.bdev)))
- closure_bio_submit(s->orig_bio, cl);
- } else if (writeback) {
- bch_writeback_add(dc);
-
- if (bio->bi_opf & REQ_PREFLUSH) {
- /* Also need to send a flush to the backing device */
- struct bio *flush = bio_alloc_bioset(GFP_NOIO, 0,
- &dc->disk.bio_split);
-
- flush->bi_bdev = bio->bi_bdev;
- flush->bi_end_io = request_endio;
- flush->bi_private = cl;
- bio_set_op_attrs(flush, REQ_OP_WRITE, WRITE_FLUSH);
-
- closure_bio_submit(flush, cl);
- }
- } else {
- struct bio *writethrough =
- bio_clone_fast(bio, GFP_NOIO, &dc->disk.bio_split);
-
- closure_bio_submit(writethrough, cl);
-
- flags |= BCH_WRITE_CACHED;
- flags |= BCH_WRITE_ALLOC_NOWAIT;
- }
-
- if (bio->bi_opf & (REQ_PREFLUSH|REQ_FUA))
- flags |= BCH_WRITE_FLUSH;
- if (bypass)
- flags |= BCH_WRITE_DISCARD;
-
- bch_write_op_init(&s->iop, dc->disk.c, &s->wbio,
- (struct disk_reservation) { 0 },
- foreground_write_point(dc->disk.c,
- (unsigned long) current),
- bkey_start_pos(&insert_key),
- NULL, flags);
-
- closure_call(&s->iop.cl, bch_write, NULL, cl);
- continue_at(cl, cached_dev_write_complete, NULL);
-}
-
-/* Cached devices - read & write stuff */
-
-static void __cached_dev_make_request(struct request_queue *q, struct bio *bio)
-{
- struct search *s;
- struct bcache_device *d = bio->bi_bdev->bd_disk->private_data;
- struct cached_dev *dc = container_of(d, struct cached_dev, disk);
- int rw = bio_data_dir(bio);
-
- generic_start_io_acct(rw, bio_sectors(bio), &d->disk->part0);
-
- bio->bi_bdev = dc->disk_sb.bdev;
- bio->bi_iter.bi_sector += le64_to_cpu(dc->disk_sb.sb->data_offset);
-
- if (cached_dev_get(dc)) {
- struct bio *clone;
-
- s = search_alloc(bio, d);
- trace_bcache_request_start(s->d, bio);
-
- clone = rw ? &s->wbio.bio : &s->rbio.bio;
-
- if (!bio->bi_iter.bi_size) {
- if (s->orig_bio->bi_opf & (REQ_PREFLUSH|REQ_FUA))
- bch_journal_flush_async(&s->iop.c->journal,
- &s->cl);
-
- /*
- * If it's a flush, we send the flush to the backing
- * device too
- */
- closure_bio_submit(clone, &s->cl);
-
- continue_at(&s->cl, cached_dev_bio_complete, NULL);
- } else {
- s->bypass = check_should_bypass(dc, bio, rw);
-
- if (rw)
- cached_dev_write(dc, s);
- else
- cached_dev_read(dc, s);
- }
- } else {
- if ((bio_op(bio) == REQ_OP_DISCARD) &&
- !blk_queue_discard(bdev_get_queue(dc->disk_sb.bdev)))
- bio_endio(bio);
- else
- generic_make_request(bio);
- }
-}
-
-static blk_qc_t cached_dev_make_request(struct request_queue *q,
- struct bio *bio)
-{
- __cached_dev_make_request(q, bio);
- return BLK_QC_T_NONE;
-}
-
-static int cached_dev_ioctl(struct bcache_device *d, fmode_t mode,
- unsigned int cmd, unsigned long arg)
-{
- struct cached_dev *dc = container_of(d, struct cached_dev, disk);
- return __blkdev_driver_ioctl(dc->disk_sb.bdev, mode, cmd, arg);
-}
-
-static int cached_dev_congested(void *data, int bits)
-{
- struct bcache_device *d = data;
- struct cached_dev *dc = container_of(d, struct cached_dev, disk);
- struct request_queue *q = bdev_get_queue(dc->disk_sb.bdev);
- int ret = 0;
-
- if (bdi_congested(&q->backing_dev_info, bits))
- return 1;
-
- if (cached_dev_get(dc)) {
- ret |= bch_congested(d->c, bits);
- cached_dev_put(dc);
- }
-
- return ret;
-}
-
-void bch_cached_dev_request_init(struct cached_dev *dc)
-{
- struct gendisk *g = dc->disk.disk;
-
- g->queue->make_request_fn = cached_dev_make_request;
- g->queue->backing_dev_info.congested_fn = cached_dev_congested;
- dc->disk.ioctl = cached_dev_ioctl;
-}
-
-/* Blockdev volumes */
-
-static void __blockdev_volume_make_request(struct request_queue *q,
- struct bio *bio)
-{
- struct search *s;
- struct bcache_device *d = bio->bi_bdev->bd_disk->private_data;
- int rw = bio_data_dir(bio);
-
- generic_start_io_acct(rw, bio_sectors(bio), &d->disk->part0);
-
- trace_bcache_request_start(d, bio);
-
- s = search_alloc(bio, d);
-
- if (!bio->bi_iter.bi_size) {
- if (s->orig_bio->bi_opf & (REQ_PREFLUSH|REQ_FUA))
- bch_journal_flush_async(&s->iop.c->journal,
- &s->cl);
-
- continue_at(&s->cl, search_free, NULL);
- } else if (rw) {
- struct disk_reservation res = { 0 };
- unsigned flags = 0;
-
- if (bio_op(bio) != REQ_OP_DISCARD &&
- bch_disk_reservation_get(d->c, &res, bio_sectors(bio), 0)) {
- s->iop.error = -ENOSPC;
- continue_at(&s->cl, search_free, NULL);
- return;
- }
-
- if (bio->bi_opf & (REQ_PREFLUSH|REQ_FUA))
- flags |= BCH_WRITE_FLUSH;
- if (bio_op(bio) == REQ_OP_DISCARD)
- flags |= BCH_WRITE_DISCARD;
-
- bch_write_op_init(&s->iop, d->c, &s->wbio, res,
- foreground_write_point(d->c,
- (unsigned long) current),
- POS(s->inode, bio->bi_iter.bi_sector),
- NULL, flags);
-
- closure_call(&s->iop.cl, bch_write, NULL, &s->cl);
- } else {
- closure_get(&s->cl);
- bch_read(d->c, &s->rbio, bcache_dev_inum(d));
- }
- continue_at(&s->cl, search_free, NULL);
-}
-
-static blk_qc_t blockdev_volume_make_request(struct request_queue *q,
- struct bio *bio)
-{
- __blockdev_volume_make_request(q, bio);
- return BLK_QC_T_NONE;
-}
-
-static int blockdev_volume_ioctl(struct bcache_device *d, fmode_t mode,
- unsigned int cmd, unsigned long arg)
-{
- return -ENOTTY;
-}
-
-static int blockdev_volume_congested(void *data, int bits)
-{
- struct bcache_device *d = data;
-
- return bch_congested(d->c, bits);
-}
-
-void bch_blockdev_volume_request_init(struct bcache_device *d)
-{
- struct gendisk *g = d->disk;
-
- g->queue->make_request_fn = blockdev_volume_make_request;
- g->queue->backing_dev_info.congested_fn = blockdev_volume_congested;
- d->ioctl = blockdev_volume_ioctl;
-}