diff options
Diffstat (limited to 'drivers/md/bcache/request.c')
| -rw-r--r-- | drivers/md/bcache/request.c | 1882 |
1 files changed, 915 insertions, 967 deletions
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index e5ff12e52d5b..af345dc6fde1 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Main bcache entry point - handle a read or a write request and decide what to * do with it; the make_request functions are called by the block layer. @@ -10,203 +11,43 @@ #include "btree.h" #include "debug.h" #include "request.h" +#include "writeback.h" -#include <linux/cgroup.h> #include <linux/module.h> #include <linux/hash.h> #include <linux/random.h> -#include "blk-cgroup.h" +#include <linux/backing-dev.h> #include <trace/events/bcache.h> #define CUTOFF_CACHE_ADD 95 #define CUTOFF_CACHE_READA 90 -#define CUTOFF_WRITEBACK 50 -#define CUTOFF_WRITEBACK_SYNC 75 struct kmem_cache *bch_search_cache; -static void check_should_skip(struct cached_dev *, struct search *); +static CLOSURE_CALLBACK(bch_data_insert_start); -/* Cgroup interface */ - -#ifdef CONFIG_CGROUP_BCACHE -static struct bch_cgroup bcache_default_cgroup = { .cache_mode = -1 }; - -static struct bch_cgroup *cgroup_to_bcache(struct cgroup *cgroup) -{ - struct cgroup_subsys_state *css; - return cgroup && - (css = cgroup_subsys_state(cgroup, bcache_subsys_id)) - ? container_of(css, struct bch_cgroup, css) - : &bcache_default_cgroup; -} - -struct bch_cgroup *bch_bio_to_cgroup(struct bio *bio) -{ - struct cgroup_subsys_state *css = bio->bi_css - ? cgroup_subsys_state(bio->bi_css->cgroup, bcache_subsys_id) - : task_subsys_state(current, bcache_subsys_id); - - return css - ? container_of(css, struct bch_cgroup, css) - : &bcache_default_cgroup; -} - -static ssize_t cache_mode_read(struct cgroup *cgrp, struct cftype *cft, - struct file *file, - char __user *buf, size_t nbytes, loff_t *ppos) -{ - char tmp[1024]; - int len = bch_snprint_string_list(tmp, PAGE_SIZE, bch_cache_modes, - cgroup_to_bcache(cgrp)->cache_mode + 1); - - if (len < 0) - return len; - - return simple_read_from_buffer(buf, nbytes, ppos, tmp, len); -} - -static int cache_mode_write(struct cgroup *cgrp, struct cftype *cft, - const char *buf) -{ - int v = bch_read_string_list(buf, bch_cache_modes); - if (v < 0) - return v; - - cgroup_to_bcache(cgrp)->cache_mode = v - 1; - return 0; -} - -static u64 bch_verify_read(struct cgroup *cgrp, struct cftype *cft) -{ - return cgroup_to_bcache(cgrp)->verify; -} - -static int bch_verify_write(struct cgroup *cgrp, struct cftype *cft, u64 val) -{ - cgroup_to_bcache(cgrp)->verify = val; - return 0; -} - -static u64 bch_cache_hits_read(struct cgroup *cgrp, struct cftype *cft) -{ - struct bch_cgroup *bcachecg = cgroup_to_bcache(cgrp); - return atomic_read(&bcachecg->stats.cache_hits); -} - -static u64 bch_cache_misses_read(struct cgroup *cgrp, struct cftype *cft) -{ - struct bch_cgroup *bcachecg = cgroup_to_bcache(cgrp); - return atomic_read(&bcachecg->stats.cache_misses); -} - -static u64 bch_cache_bypass_hits_read(struct cgroup *cgrp, - struct cftype *cft) +static unsigned int cache_mode(struct cached_dev *dc) { - struct bch_cgroup *bcachecg = cgroup_to_bcache(cgrp); - return atomic_read(&bcachecg->stats.cache_bypass_hits); -} - -static u64 bch_cache_bypass_misses_read(struct cgroup *cgrp, - struct cftype *cft) -{ - struct bch_cgroup *bcachecg = cgroup_to_bcache(cgrp); - return atomic_read(&bcachecg->stats.cache_bypass_misses); -} - -static struct cftype bch_files[] = { - { - .name = "cache_mode", - .read = cache_mode_read, - .write_string = cache_mode_write, - }, - { - .name = "verify", - .read_u64 = bch_verify_read, - .write_u64 = bch_verify_write, - }, - { - .name = "cache_hits", - .read_u64 = bch_cache_hits_read, - }, - { - .name = "cache_misses", - .read_u64 = bch_cache_misses_read, - }, - { - .name = "cache_bypass_hits", - .read_u64 = bch_cache_bypass_hits_read, - }, - { - .name = "cache_bypass_misses", - .read_u64 = bch_cache_bypass_misses_read, - }, - { } /* terminate */ -}; - -static void init_bch_cgroup(struct bch_cgroup *cg) -{ - cg->cache_mode = -1; -} - -static struct cgroup_subsys_state *bcachecg_create(struct cgroup *cgroup) -{ - struct bch_cgroup *cg; - - cg = kzalloc(sizeof(*cg), GFP_KERNEL); - if (!cg) - return ERR_PTR(-ENOMEM); - init_bch_cgroup(cg); - return &cg->css; -} - -static void bcachecg_destroy(struct cgroup *cgroup) -{ - struct bch_cgroup *cg = cgroup_to_bcache(cgroup); - free_css_id(&bcache_subsys, &cg->css); - kfree(cg); -} - -struct cgroup_subsys bcache_subsys = { - .create = bcachecg_create, - .destroy = bcachecg_destroy, - .subsys_id = bcache_subsys_id, - .name = "bcache", - .module = THIS_MODULE, -}; -EXPORT_SYMBOL_GPL(bcache_subsys); -#endif - -static unsigned cache_mode(struct cached_dev *dc, struct bio *bio) -{ -#ifdef CONFIG_CGROUP_BCACHE - int r = bch_bio_to_cgroup(bio)->cache_mode; - if (r >= 0) - return r; -#endif return BDEV_CACHE_MODE(&dc->sb); } -static bool verify(struct cached_dev *dc, struct bio *bio) +static bool verify(struct cached_dev *dc) { -#ifdef CONFIG_CGROUP_BCACHE - if (bch_bio_to_cgroup(bio)->verify) - return true; -#endif return dc->verify; } static void bio_csum(struct bio *bio, struct bkey *k) { - struct bio_vec *bv; + struct bio_vec bv; + struct bvec_iter iter; uint64_t csum = 0; - int i; - bio_for_each_segment(bv, bio, i) { - void *d = kmap(bv->bv_page) + bv->bv_offset; - csum = bch_crc64_update(csum, d, bv->bv_len); - kunmap(bv->bv_page); + bio_for_each_segment(bv, bio, iter) { + void *d = bvec_kmap_local(&bv); + + csum = crc64_be(csum, d, bv.bv_len); + kunmap_local(d); } k->ptr[KEY_PTRS(k)] = csum & (~0ULL >> 1); @@ -214,311 +55,181 @@ static void bio_csum(struct bio *bio, struct bkey *k) /* Insert data into cache */ -static void bio_invalidate(struct closure *cl) +static CLOSURE_CALLBACK(bch_data_insert_keys) { - struct btree_op *op = container_of(cl, struct btree_op, cl); - struct bio *bio = op->cache_bio; - - pr_debug("invalidating %i sectors from %llu", - bio_sectors(bio), (uint64_t) bio->bi_sector); - - while (bio_sectors(bio)) { - unsigned len = min(bio_sectors(bio), 1U << 14); - - if (bch_keylist_realloc(&op->keys, 0, op->c)) - goto out; - - bio->bi_sector += len; - bio->bi_size -= len << 9; - - bch_keylist_add(&op->keys, - &KEY(op->inode, bio->bi_sector, len)); - } - - op->insert_data_done = true; - bio_put(bio); -out: - continue_at(cl, bch_journal, bcache_wq); -} - -struct open_bucket { - struct list_head list; - struct task_struct *last; - unsigned sectors_free; - BKEY_PADDED(key); -}; - -void bch_open_buckets_free(struct cache_set *c) -{ - struct open_bucket *b; - - while (!list_empty(&c->data_buckets)) { - b = list_first_entry(&c->data_buckets, - struct open_bucket, list); - list_del(&b->list); - kfree(b); - } -} - -int bch_open_buckets_alloc(struct cache_set *c) -{ - int i; - - spin_lock_init(&c->data_bucket_lock); - - for (i = 0; i < 6; i++) { - struct open_bucket *b = kzalloc(sizeof(*b), GFP_KERNEL); - if (!b) - return -ENOMEM; - - list_add(&b->list, &c->data_buckets); + closure_type(op, struct data_insert_op, cl); + atomic_t *journal_ref = NULL; + struct bkey *replace_key = op->replace ? &op->replace_key : NULL; + int ret; + + if (!op->replace) + journal_ref = bch_journal(op->c, &op->insert_keys, + op->flush_journal ? cl : NULL); + + ret = bch_btree_insert(op->c, &op->insert_keys, + journal_ref, replace_key); + if (ret == -ESRCH) { + op->replace_collision = true; + } else if (ret) { + op->status = BLK_STS_RESOURCE; + op->insert_data_done = true; } - return 0; -} + if (journal_ref) + atomic_dec_bug(journal_ref); -/* - * We keep multiple buckets open for writes, and try to segregate different - * write streams for better cache utilization: first we look for a bucket where - * the last write to it was sequential with the current write, and failing that - * we look for a bucket that was last used by the same task. - * - * The ideas is if you've got multiple tasks pulling data into the cache at the - * same time, you'll get better cache utilization if you try to segregate their - * data and preserve locality. - * - * For example, say you've starting Firefox at the same time you're copying a - * bunch of files. Firefox will likely end up being fairly hot and stay in the - * cache awhile, but the data you copied might not be; if you wrote all that - * data to the same buckets it'd get invalidated at the same time. - * - * Both of those tasks will be doing fairly random IO so we can't rely on - * detecting sequential IO to segregate their data, but going off of the task - * should be a sane heuristic. - */ -static struct open_bucket *pick_data_bucket(struct cache_set *c, - const struct bkey *search, - struct task_struct *task, - struct bkey *alloc) -{ - struct open_bucket *ret, *ret_task = NULL; - - list_for_each_entry_reverse(ret, &c->data_buckets, list) - if (!bkey_cmp(&ret->key, search)) - goto found; - else if (ret->last == task) - ret_task = ret; - - ret = ret_task ?: list_first_entry(&c->data_buckets, - struct open_bucket, list); -found: - if (!ret->sectors_free && KEY_PTRS(alloc)) { - ret->sectors_free = c->sb.bucket_size; - bkey_copy(&ret->key, alloc); - bkey_init(alloc); + if (!op->insert_data_done) { + continue_at(cl, bch_data_insert_start, op->wq); + return; } - if (!ret->sectors_free) - ret = NULL; - - return ret; + bch_keylist_free(&op->insert_keys); + closure_return(cl); } -/* - * Allocates some space in the cache to write to, and k to point to the newly - * allocated space, and updates KEY_SIZE(k) and KEY_OFFSET(k) (to point to the - * end of the newly allocated space). - * - * May allocate fewer sectors than @sectors, KEY_SIZE(k) indicates how many - * sectors were actually allocated. - * - * If s->writeback is true, will not fail. - */ -static bool bch_alloc_sectors(struct bkey *k, unsigned sectors, - struct search *s) +static int bch_keylist_realloc(struct keylist *l, unsigned int u64s, + struct cache_set *c) { - struct cache_set *c = s->op.c; - struct open_bucket *b; - BKEY_PADDED(key) alloc; - struct closure cl, *w = NULL; - unsigned i; - - if (s->writeback) { - closure_init_stack(&cl); - w = &cl; - } + size_t oldsize = bch_keylist_nkeys(l); + size_t newsize = oldsize + u64s; /* - * We might have to allocate a new bucket, which we can't do with a - * spinlock held. So if we have to allocate, we drop the lock, allocate - * and then retry. KEY_PTRS() indicates whether alloc points to - * allocated bucket(s). + * The journalling code doesn't handle the case where the keys to insert + * is bigger than an empty write: If we just return -ENOMEM here, + * bch_data_insert_keys() will insert the keys created so far + * and finish the rest when the keylist is empty. */ + if (newsize * sizeof(uint64_t) > block_bytes(c->cache) - sizeof(struct jset)) + return -ENOMEM; - bkey_init(&alloc.key); - spin_lock(&c->data_bucket_lock); - - while (!(b = pick_data_bucket(c, k, s->task, &alloc.key))) { - unsigned watermark = s->op.write_prio - ? WATERMARK_MOVINGGC - : WATERMARK_NONE; - - spin_unlock(&c->data_bucket_lock); - - if (bch_bucket_alloc_set(c, watermark, &alloc.key, 1, w)) - return false; - - spin_lock(&c->data_bucket_lock); - } - - /* - * If we had to allocate, we might race and not need to allocate the - * second time we call find_data_bucket(). If we allocated a bucket but - * didn't use it, drop the refcount bch_bucket_alloc_set() took: - */ - if (KEY_PTRS(&alloc.key)) - __bkey_put(c, &alloc.key); - - for (i = 0; i < KEY_PTRS(&b->key); i++) - EBUG_ON(ptr_stale(c, &b->key, i)); - - /* Set up the pointer to the space we're allocating: */ - - for (i = 0; i < KEY_PTRS(&b->key); i++) - k->ptr[i] = b->key.ptr[i]; + return __bch_keylist_realloc(l, u64s); +} - sectors = min(sectors, b->sectors_free); +static void bch_data_invalidate(struct closure *cl) +{ + struct data_insert_op *op = container_of(cl, struct data_insert_op, cl); + struct bio *bio = op->bio; - SET_KEY_OFFSET(k, KEY_OFFSET(k) + sectors); - SET_KEY_SIZE(k, sectors); - SET_KEY_PTRS(k, KEY_PTRS(&b->key)); + pr_debug("invalidating %i sectors from %llu\n", + bio_sectors(bio), (uint64_t) bio->bi_iter.bi_sector); - /* - * Move b to the end of the lru, and keep track of what this bucket was - * last used for: - */ - list_move_tail(&b->list, &c->data_buckets); - bkey_copy_key(&b->key, k); - b->last = s->task; + while (bio_sectors(bio)) { + unsigned int sectors = min(bio_sectors(bio), + 1U << (KEY_SIZE_BITS - 1)); - b->sectors_free -= sectors; + if (bch_keylist_realloc(&op->insert_keys, 2, op->c)) + goto out; - for (i = 0; i < KEY_PTRS(&b->key); i++) { - SET_PTR_OFFSET(&b->key, i, PTR_OFFSET(&b->key, i) + sectors); + bio->bi_iter.bi_sector += sectors; + bio->bi_iter.bi_size -= sectors << 9; - atomic_long_add(sectors, - &PTR_CACHE(c, &b->key, i)->sectors_written); + bch_keylist_add(&op->insert_keys, + &KEY(op->inode, + bio->bi_iter.bi_sector, + sectors)); } - if (b->sectors_free < c->sb.block_size) - b->sectors_free = 0; - - /* - * k takes refcounts on the buckets it points to until it's inserted - * into the btree, but if we're done with this bucket we just transfer - * get_data_bucket()'s refcount. - */ - if (b->sectors_free) - for (i = 0; i < KEY_PTRS(&b->key); i++) - atomic_inc(&PTR_BUCKET(c, &b->key, i)->pin); - - spin_unlock(&c->data_bucket_lock); - return true; + op->insert_data_done = true; + /* get in bch_data_insert() */ + bio_put(bio); +out: + continue_at(cl, bch_data_insert_keys, op->wq); } -static void bch_insert_data_error(struct closure *cl) +static CLOSURE_CALLBACK(bch_data_insert_error) { - struct btree_op *op = container_of(cl, struct btree_op, cl); + closure_type(op, struct data_insert_op, cl); /* * Our data write just errored, which means we've got a bunch of keys to - * insert that point to data that wasn't succesfully written. + * insert that point to data that wasn't successfully written. * * We don't have to insert those keys but we still have to invalidate * that region of the cache - so, if we just strip off all the pointers * from the keys we'll accomplish just that. */ - struct bkey *src = op->keys.bottom, *dst = op->keys.bottom; + struct bkey *src = op->insert_keys.keys, *dst = op->insert_keys.keys; - while (src != op->keys.top) { + while (src != op->insert_keys.top) { struct bkey *n = bkey_next(src); SET_KEY_PTRS(src, 0); - bkey_copy(dst, src); + memmove(dst, src, bkey_bytes(src)); dst = bkey_next(dst); src = n; } - op->keys.top = dst; + op->insert_keys.top = dst; - bch_journal(cl); + bch_data_insert_keys(&cl->work); } -static void bch_insert_data_endio(struct bio *bio, int error) +static void bch_data_insert_endio(struct bio *bio) { struct closure *cl = bio->bi_private; - struct btree_op *op = container_of(cl, struct btree_op, cl); - struct search *s = container_of(op, struct search, op); + struct data_insert_op *op = container_of(cl, struct data_insert_op, cl); - if (error) { + if (bio->bi_status) { /* TODO: We could try to recover from this. */ - if (s->writeback) - s->error = error; - else if (s->write) - set_closure_fn(cl, bch_insert_data_error, bcache_wq); + if (op->writeback) + op->status = bio->bi_status; + else if (!op->replace) + set_closure_fn(cl, bch_data_insert_error, op->wq); else set_closure_fn(cl, NULL, NULL); } - bch_bbio_endio(op->c, bio, error, "writing data to cache"); + bch_bbio_endio(op->c, bio, bio->bi_status, "writing data to cache"); } -static void bch_insert_data_loop(struct closure *cl) +static CLOSURE_CALLBACK(bch_data_insert_start) { - struct btree_op *op = container_of(cl, struct btree_op, cl); - struct search *s = container_of(op, struct search, op); - struct bio *bio = op->cache_bio, *n; + closure_type(op, struct data_insert_op, cl); + struct bio *bio = op->bio, *n; - if (op->skip) - return bio_invalidate(cl); + if (op->bypass) + return bch_data_invalidate(cl); - if (atomic_sub_return(bio_sectors(bio), &op->c->sectors_to_gc) < 0) { - set_gc_sectors(op->c); - bch_queue_gc(op->c); - } + if (atomic_sub_return(bio_sectors(bio), &op->c->sectors_to_gc) < 0) + wake_up_gc(op->c); + + /* + * Journal writes are marked REQ_PREFLUSH; if the original write was a + * flush, it'll wait on the journal write. + */ + bio->bi_opf &= ~(REQ_PREFLUSH|REQ_FUA); do { - unsigned i; + unsigned int i; struct bkey *k; - struct bio_set *split = s->d - ? s->d->bio_split : op->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(&op->keys, - 1 + (op->csum ? 1 : 0), - op->c)) - continue_at(cl, bch_journal, bcache_wq); + if (bch_keylist_realloc(&op->insert_keys, + 3 + (op->csum ? 1 : 0), + op->c)) { + continue_at(cl, bch_data_insert_keys, op->wq); + return; + } - k = op->keys.top; + k = op->insert_keys.top; bkey_init(k); SET_KEY_INODE(k, op->inode); - SET_KEY_OFFSET(k, bio->bi_sector); + SET_KEY_OFFSET(k, bio->bi_iter.bi_sector); - if (!bch_alloc_sectors(k, bio_sectors(bio), s)) + if (!bch_alloc_sectors(op->c, k, bio_sectors(bio), + op->write_point, op->write_prio, + op->writeback)) goto err; - n = bch_bio_split(bio, KEY_SIZE(k), GFP_NOIO, split); - if (!n) { - __bkey_put(op->c, k); - continue_at(cl, bch_insert_data_loop, bcache_wq); - } + n = bio_next_split(bio, KEY_SIZE(k), GFP_NOIO, split); - n->bi_end_io = bch_insert_data_endio; + 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++) @@ -530,19 +241,19 @@ static void bch_insert_data_loop(struct closure *cl) if (KEY_CSUM(k)) bio_csum(n, k); - pr_debug("%s", pkey(k)); - bch_keylist_push(&op->keys); + trace_bcache_cache_insert(k); + bch_keylist_push(&op->insert_keys); - trace_bcache_cache_insert(n, n->bi_sector, n->bi_bdev); - n->bi_rw |= REQ_WRITE; + n->bi_opf = REQ_OP_WRITE; bch_submit_bbio(n, op->c, k, 0); } while (n != bio); op->insert_data_done = true; - continue_at(cl, bch_journal, bcache_wq); + continue_at(cl, bch_data_insert_keys, op->wq); + return; 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 @@ -550,15 +261,15 @@ 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. */ - op->skip = true; - return bio_invalidate(cl); + op->bypass = true; + return bch_data_invalidate(cl); } else { /* * From a cache miss, we can just insert the keys for the data @@ -567,15 +278,16 @@ err: op->insert_data_done = true; bio_put(bio); - if (!bch_keylist_empty(&op->keys)) - continue_at(cl, bch_journal, bcache_wq); + if (!bch_keylist_empty(&op->insert_keys)) + continue_at(cl, bch_data_insert_keys, op->wq); else closure_return(cl); } } /** - * bch_insert_data - stick some data in the cache + * bch_data_insert - stick some data in the cache + * @cl: closure pointer. * * This is the starting point for any data to end up in a cache device; it could * be from a normal write, or a writeback write, or a write to a flash only @@ -587,56 +299,204 @@ err: * data is written it calls bch_journal, and after the keys have been added to * the next journal write they're inserted into the btree. * - * It inserts the data in op->cache_bio; bi_sector is used for the key offset, + * It inserts the data in op->bio; bi_sector is used for the key offset, * and op->inode is used for the key inode. * - * If op->skip is true, instead of inserting the data it invalidates the region - * of the cache represented by op->cache_bio and op->inode. + * If op->bypass is true, instead of inserting the data it invalidates the + * region of the cache represented by op->bio and op->inode. */ -void bch_insert_data(struct closure *cl) +CLOSURE_CALLBACK(bch_data_insert) { - struct btree_op *op = container_of(cl, struct btree_op, cl); + closure_type(op, struct data_insert_op, cl); - bch_keylist_init(&op->keys); - bio_get(op->cache_bio); - bch_insert_data_loop(cl); + trace_bcache_write(op->c, op->inode, op->bio, + op->writeback, op->bypass); + + bch_keylist_init(&op->insert_keys); + bio_get(op->bio); + bch_data_insert_start(&cl->work); } -void bch_btree_insert_async(struct closure *cl) +/* + * Congested? Return 0 (not congested) or the limit (in sectors) + * beyond which we should bypass the cache due to congestion. + */ +unsigned int bch_get_congested(const struct cache_set *c) { - struct btree_op *op = container_of(cl, struct btree_op, cl); - struct search *s = container_of(op, struct search, op); + int i; - if (bch_btree_insert(op, op->c)) { - s->error = -ENOMEM; - op->insert_data_done = true; - } + if (!c->congested_read_threshold_us && + !c->congested_write_threshold_us) + return 0; - if (op->insert_data_done) { - bch_keylist_free(&op->keys); - closure_return(cl); - } else - continue_at(cl, bch_insert_data_loop, bcache_wq); + 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); + + i -= hweight32(get_random_u32()); + + return i > 0 ? i : 1; } -/* Common code for the make_request functions */ +static void add_sequential(struct task_struct *t) +{ + ewma_add(t->sequential_io_avg, + t->sequential_io, 8, 0); -static void request_endio(struct bio *bio, int error) + t->sequential_io = 0; +} + +static struct hlist_head *iohash(struct cached_dev *dc, uint64_t k) { - struct closure *cl = bio->bi_private; + return &dc->io_hash[hash_64(k, RECENT_IO_BITS)]; +} - if (error) { - struct search *s = container_of(cl, struct search, cl); - s->error = error; - /* Only cache read errors are recoverable */ - s->recoverable = false; +static bool check_should_bypass(struct cached_dev *dc, struct bio *bio) +{ + struct cache_set *c = dc->disk.c; + unsigned int mode = cache_mode(dc); + unsigned int sectors, congested; + struct task_struct *task = current; + struct io *i; + + if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) || + (bio_op(bio) == REQ_OP_DISCARD)) + goto skip; + + if (c->gc_stats.in_use > CUTOFF_CACHE_ADD) { + /* + * If cached buckets are all clean now, 'true' will be + * returned and all requests will bypass the cache device. + * Then c->sectors_to_gc has no chance to be negative, and + * gc thread won't wake up and caching won't work forever. + * Here call force_wake_up_gc() to avoid such aftermath. + */ + if (BDEV_STATE(&dc->sb) == BDEV_STATE_CLEAN && + c->gc_mark_valid) + force_wake_up_gc(c); + + goto skip; } - bio_put(bio); - closure_put(cl); + if (mode == CACHE_MODE_NONE || + (mode == CACHE_MODE_WRITEAROUND && + op_is_write(bio_op(bio)))) + goto skip; + + /* + * If the bio is for read-ahead or background IO, bypass it or + * not depends on the following situations, + * - If the IO is for meta data, always cache it and no bypass + * - If the IO is not meta data, check dc->cache_reada_policy, + * BCH_CACHE_READA_ALL: cache it and not bypass + * BCH_CACHE_READA_META_ONLY: not cache it and bypass + * That is, read-ahead request for metadata always get cached + * (eg, for gfs2 or xfs). + */ + if ((bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND))) { + if (!(bio->bi_opf & (REQ_META|REQ_PRIO)) && + (dc->cache_readahead_policy != BCH_CACHE_READA_ALL)) + goto skip; + } + + if (bio->bi_iter.bi_sector & (c->cache->sb.block_size - 1) || + bio_sectors(bio) & (c->cache->sb.block_size - 1)) { + pr_debug("skipping unaligned io\n"); + goto skip; + } + + if (bypass_torture_test(dc)) { + if (get_random_u32_below(4) == 3) + goto skip; + else + goto rescale; + } + + congested = bch_get_congested(c); + if (!congested && !dc->sequential_cutoff) + 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->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_iter.bi_size > i->sequential) + i->sequential += bio->bi_iter.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); + + 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; } -void bch_cache_read_endio(struct bio *bio, int error) +/* Cache lookup */ + +struct search { + /* Stack frame for bio_complete */ + struct closure cl; + + struct bbio bio; + struct bio *orig_bio; + struct bio *cache_miss; + struct bcache_device *d; + + unsigned int insert_bio_sectors; + unsigned int recoverable:1; + unsigned int write:1; + unsigned int read_dirty_data:1; + unsigned int cache_missed:1; + + struct block_device *orig_bdev; + unsigned long start_time; + + struct btree_op op; + struct data_insert_op iop; +}; + +static void bch_cache_read_endio(struct bio *bio) { struct bbio *b = container_of(bio, struct bbio, bio); struct closure *cl = bio->bi_private; @@ -649,636 +509,753 @@ void bch_cache_read_endio(struct bio *bio, int error) * from the backing device. */ - if (error) - s->error = error; - else if (ptr_stale(s->op.c, &b->key, 0)) { - atomic_long_inc(&s->op.c->cache_read_races); - s->error = -EINTR; + if (bio->bi_status) + s->iop.status = bio->bi_status; + else if (!KEY_DIRTY(&b->key) && + ptr_stale(s->iop.c, &b->key, 0)) { + atomic_long_inc(&s->iop.c->cache_read_races); + s->iop.status = BLK_STS_IOERR; } - bch_bbio_endio(s->op.c, bio, error, "reading from cache"); + bch_bbio_endio(s->iop.c, bio, bio->bi_status, "reading from cache"); } -static void bio_complete(struct search *s) +/* + * Read from a single key, handling the initial cache miss if the key starts in + * the middle of the bio + */ +static int cache_lookup_fn(struct btree_op *op, struct btree *b, struct bkey *k) { - if (s->orig_bio) { - int cpu, rw = bio_data_dir(s->orig_bio); - unsigned long duration = jiffies - s->start_time; + struct search *s = container_of(op, struct search, op); + struct bio *n, *bio = &s->bio.bio; + struct bkey *bio_key; + unsigned int ptr; + + if (bkey_cmp(k, &KEY(s->iop.inode, bio->bi_iter.bi_sector, 0)) <= 0) + return MAP_CONTINUE; + + if (KEY_INODE(k) != s->iop.inode || + KEY_START(k) > bio->bi_iter.bi_sector) { + unsigned int bio_sectors = bio_sectors(bio); + unsigned int sectors = KEY_INODE(k) == s->iop.inode + ? min_t(uint64_t, INT_MAX, + KEY_START(k) - bio->bi_iter.bi_sector) + : INT_MAX; + int ret = s->d->cache_miss(b, s, bio, sectors); + + if (ret != MAP_CONTINUE) + return ret; + + /* if this was a complete miss we shouldn't get here */ + BUG_ON(bio_sectors <= sectors); + } - cpu = part_stat_lock(); - part_round_stats(cpu, &s->d->disk->part0); - part_stat_add(cpu, &s->d->disk->part0, ticks[rw], duration); - part_stat_unlock(); + if (!KEY_SIZE(k)) + return MAP_CONTINUE; - trace_bcache_request_end(s, s->orig_bio); - bio_endio(s->orig_bio, s->error); - s->orig_bio = NULL; - } + /* XXX: figure out best pointer - for multiple cache devices */ + ptr = 0; + + PTR_BUCKET(b->c, k, ptr)->prio = INITIAL_PRIO; + + if (KEY_DIRTY(k)) + s->read_dirty_data = true; + + n = bio_next_split(bio, min_t(uint64_t, INT_MAX, + KEY_OFFSET(k) - bio->bi_iter.bi_sector), + GFP_NOIO, &s->d->bio_split); + + bio_key = &container_of(n, struct bbio, bio)->key; + bch_bkey_copy_single_ptr(bio_key, k, ptr); + + bch_cut_front(&KEY(s->iop.inode, n->bi_iter.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; + + /* + * 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_submit_bbio(n, b->c); + return n == bio ? MAP_DONE : MAP_CONTINUE; } -static void do_bio_hook(struct search *s) +static CLOSURE_CALLBACK(cache_lookup) { + closure_type(s, struct search, iop.cl); struct bio *bio = &s->bio.bio; - memcpy(bio, s->orig_bio, sizeof(struct bio)); + struct cached_dev *dc; + int ret; - bio->bi_end_io = request_endio; - bio->bi_private = &s->cl; - atomic_set(&bio->bi_cnt, 3); + bch_btree_op_init(&s->op, -1); + + ret = bch_btree_map_keys(&s->op, s->iop.c, + &KEY(s->iop.inode, bio->bi_iter.bi_sector, 0), + cache_lookup_fn, MAP_END_KEY); + if (ret == -EAGAIN) { + continue_at(cl, cache_lookup, bcache_wq); + return; + } + + /* + * We might meet err when searching the btree, If that happens, we will + * get negative ret, in this scenario we should not recover data from + * backing device (when cache device is dirty) because we don't know + * whether bkeys the read request covered are all clean. + * + * And after that happened, s->iop.status is still its initial value + * before we submit s->bio.bio + */ + if (ret < 0) { + BUG_ON(ret == -EINTR); + if (s->d && s->d->c && + !UUID_FLASH_ONLY(&s->d->c->uuids[s->d->id])) { + dc = container_of(s->d, struct cached_dev, disk); + if (dc && atomic_read(&dc->has_dirty)) + s->recoverable = false; + } + if (!s->iop.status) + s->iop.status = BLK_STS_IOERR; + } + + closure_return(cl); } -static void search_free(struct closure *cl) +/* Common code for the make_request functions */ + +static void request_endio(struct bio *bio) { - struct search *s = container_of(cl, struct search, cl); - bio_complete(s); + struct closure *cl = bio->bi_private; - if (s->op.cache_bio) - bio_put(s->op.cache_bio); + if (bio->bi_status) { + struct search *s = container_of(cl, struct search, cl); - if (s->unaligned_bvec) - mempool_free(s->bio.bio.bi_io_vec, s->d->unaligned_bvec); + s->iop.status = bio->bi_status; + /* Only cache read errors are recoverable */ + s->recoverable = false; + } - closure_debug_destroy(cl); - mempool_free(s, s->d->c->search); + bio_put(bio); + closure_put(cl); } -static struct search *search_alloc(struct bio *bio, struct bcache_device *d) +static void backing_request_endio(struct bio *bio) { - struct bio_vec *bv; - struct search *s = mempool_alloc(d->c->search, GFP_NOIO); - memset(s, 0, offsetof(struct search, op.keys)); - - __closure_init(&s->cl, NULL); + struct closure *cl = bio->bi_private; - s->op.inode = d->id; - s->op.c = d->c; - s->d = d; - s->op.lock = -1; - s->task = current; - s->orig_bio = bio; - s->write = (bio->bi_rw & REQ_WRITE) != 0; - s->op.flush_journal = (bio->bi_rw & REQ_FLUSH) != 0; - s->op.skip = (bio->bi_rw & REQ_DISCARD) != 0; - s->recoverable = 1; - s->start_time = jiffies; - do_bio_hook(s); + if (bio->bi_status) { + struct search *s = container_of(cl, struct search, cl); + struct cached_dev *dc = container_of(s->d, + struct cached_dev, disk); + /* + * If a bio has REQ_PREFLUSH for writeback mode, it is + * speically assembled in cached_dev_write() for a non-zero + * write request which has REQ_PREFLUSH. we don't set + * s->iop.status by this failure, the status will be decided + * by result of bch_data_insert() operation. + */ + if (unlikely(s->iop.writeback && + bio->bi_opf & REQ_PREFLUSH)) { + pr_err("Can't flush %pg: returned bi_status %i\n", + dc->bdev, bio->bi_status); + } else { + /* set to orig_bio->bi_status in bio_complete() */ + s->iop.status = bio->bi_status; + } + s->recoverable = false; + /* should count I/O error for backing device here */ + bch_count_backing_io_errors(dc, bio); + } - if (bio->bi_size != bio_segments(bio) * PAGE_SIZE) { - bv = mempool_alloc(d->unaligned_bvec, GFP_NOIO); - memcpy(bv, bio_iovec(bio), - sizeof(struct bio_vec) * bio_segments(bio)); + bio_put(bio); + closure_put(cl); +} - s->bio.bio.bi_io_vec = bv; - s->unaligned_bvec = 1; +static void bio_complete(struct search *s) +{ + if (s->orig_bio) { + /* Count on bcache device */ + bio_end_io_acct_remapped(s->orig_bio, s->start_time, + s->orig_bdev); + trace_bcache_request_end(s->d, s->orig_bio); + s->orig_bio->bi_status = s->iop.status; + bio_endio(s->orig_bio); + s->orig_bio = NULL; } +} - return s; +static void do_bio_hook(struct search *s, + struct bio *orig_bio, + bio_end_io_t *end_io_fn) +{ + struct bio *bio = &s->bio.bio; + + bio_init_clone(orig_bio->bi_bdev, bio, orig_bio, GFP_NOIO); + /* + * bi_end_io can be set separately somewhere else, e.g. the + * variants in, + * - cache_bio->bi_end_io from cached_dev_cache_miss() + * - n->bi_end_io from cache_lookup_fn() + */ + bio->bi_end_io = end_io_fn; + bio->bi_private = &s->cl; + + bio_cnt_set(bio, 3); } -static void btree_read_async(struct closure *cl) +static CLOSURE_CALLBACK(search_free) { - struct btree_op *op = container_of(cl, struct btree_op, cl); + closure_type(s, struct search, cl); - int ret = btree_root(search_recurse, op->c, op); + atomic_dec(&s->iop.c->search_inflight); - if (ret == -EAGAIN) - continue_at(cl, btree_read_async, bcache_wq); + if (s->iop.bio) + bio_put(s->iop.bio); - closure_return(cl); + bio_complete(s); + closure_debug_destroy(cl); + mempool_free(s, &s->iop.c->search); +} + +static inline struct search *search_alloc(struct bio *bio, + struct bcache_device *d, struct block_device *orig_bdev, + unsigned long start_time) +{ + struct search *s; + + s = mempool_alloc(&d->c->search, GFP_NOIO); + + closure_init(&s->cl, NULL); + do_bio_hook(s, bio, request_endio); + atomic_inc(&d->c->search_inflight); + + s->orig_bio = bio; + s->cache_miss = NULL; + s->cache_missed = 0; + s->d = d; + s->recoverable = 1; + s->write = op_is_write(bio_op(bio)); + s->read_dirty_data = 0; + /* Count on the bcache device */ + s->orig_bdev = orig_bdev; + s->start_time = start_time; + s->iop.c = d->c; + s->iop.bio = NULL; + s->iop.inode = d->id; + s->iop.write_point = hash_long((unsigned long) current, 16); + s->iop.write_prio = 0; + s->iop.status = 0; + s->iop.flags = 0; + s->iop.flush_journal = op_is_flush(bio->bi_opf); + s->iop.wq = bcache_wq; + + return s; } /* Cached devices */ -static void cached_dev_bio_complete(struct closure *cl) +static CLOSURE_CALLBACK(cached_dev_bio_complete) { - struct search *s = container_of(cl, struct search, cl); + closure_type(s, struct search, cl); struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); - search_free(cl); cached_dev_put(dc); + search_free(&cl->work); } /* Process reads */ -static void cached_dev_read_complete(struct closure *cl) +static CLOSURE_CALLBACK(cached_dev_read_error_done) { - struct search *s = container_of(cl, struct search, cl); - - if (s->op.insert_collision) - bch_mark_cache_miss_collision(s); + closure_type(s, struct search, cl); - if (s->op.cache_bio) { - int i; - struct bio_vec *bv; + if (s->iop.replace_collision) + bch_mark_cache_miss_collision(s->iop.c, s->d); - __bio_for_each_segment(bv, s->op.cache_bio, i, 0) - __free_page(bv->bv_page); - } + if (s->iop.bio) + bio_free_pages(s->iop.bio); - cached_dev_bio_complete(cl); + cached_dev_bio_complete(&cl->work); } -static void request_read_error(struct closure *cl) +static CLOSURE_CALLBACK(cached_dev_read_error) { - struct search *s = container_of(cl, struct search, cl); - struct bio_vec *bv; - int i; - - if (s->recoverable) { - /* The cache read failed, but we can retry from the backing - * device. - */ - pr_debug("recovering at sector %llu", - (uint64_t) s->orig_bio->bi_sector); + closure_type(s, struct search, cl); + struct bio *bio = &s->bio.bio; - s->error = 0; - bv = s->bio.bio.bi_io_vec; - do_bio_hook(s); - s->bio.bio.bi_io_vec = bv; + /* + * If read request hit dirty data (s->read_dirty_data is true), + * then recovery a failed read request from cached device may + * get a stale data back. So read failure recovery is only + * permitted when read request hit clean data in cache device, + * or when cache read race happened. + */ + if (s->recoverable && !s->read_dirty_data) { + /* Retry from the backing device: */ + trace_bcache_read_retry(s->orig_bio); - if (!s->unaligned_bvec) - bio_for_each_segment(bv, s->orig_bio, i) - bv->bv_offset = 0, bv->bv_len = PAGE_SIZE; - else - memcpy(s->bio.bio.bi_io_vec, - bio_iovec(s->orig_bio), - sizeof(struct bio_vec) * - bio_segments(s->orig_bio)); + s->iop.status = 0; + do_bio_hook(s, s->orig_bio, backing_request_endio); /* XXX: invalidate cache */ - trace_bcache_read_retry(&s->bio.bio); - closure_bio_submit(&s->bio.bio, &s->cl, s->d); + /* I/O request sent to backing device */ + closure_bio_submit(s->iop.c, bio, cl); } - continue_at(cl, cached_dev_read_complete, NULL); + continue_at(cl, cached_dev_read_error_done, NULL); } -static void request_read_done(struct closure *cl) +static CLOSURE_CALLBACK(cached_dev_cache_miss_done) { - struct search *s = container_of(cl, struct search, cl); + closure_type(s, struct search, cl); + struct bcache_device *d = s->d; + + if (s->iop.replace_collision) + bch_mark_cache_miss_collision(s->iop.c, s->d); + + if (s->iop.bio) + bio_free_pages(s->iop.bio); + + cached_dev_bio_complete(&cl->work); + closure_put(&d->cl); +} + +static CLOSURE_CALLBACK(cached_dev_read_done) +{ + closure_type(s, struct search, cl); struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); /* - * s->cache_bio != NULL implies that we had a cache miss; cache_bio now - * contains data ready to be inserted into the cache. + * We had a cache miss; cache_bio now contains data ready to be inserted + * into the cache. * * First, we copy the data we just read from cache_bio's bounce buffers * to the buffers the original bio pointed to: */ - if (s->op.cache_bio) { - struct bio_vec *src, *dst; - unsigned src_offset, dst_offset, bytes; - void *dst_ptr; - - bio_reset(s->op.cache_bio); - s->op.cache_bio->bi_sector = s->cache_miss->bi_sector; - s->op.cache_bio->bi_bdev = s->cache_miss->bi_bdev; - s->op.cache_bio->bi_size = s->cache_bio_sectors << 9; - bch_bio_map(s->op.cache_bio, NULL); - - src = bio_iovec(s->op.cache_bio); - dst = bio_iovec(s->cache_miss); - src_offset = src->bv_offset; - dst_offset = dst->bv_offset; - dst_ptr = kmap(dst->bv_page); - - while (1) { - if (dst_offset == dst->bv_offset + dst->bv_len) { - kunmap(dst->bv_page); - dst++; - if (dst == bio_iovec_idx(s->cache_miss, - s->cache_miss->bi_vcnt)) - break; - - dst_offset = dst->bv_offset; - dst_ptr = kmap(dst->bv_page); - } - - if (src_offset == src->bv_offset + src->bv_len) { - src++; - if (src == bio_iovec_idx(s->op.cache_bio, - s->op.cache_bio->bi_vcnt)) - BUG(); + if (s->iop.bio) { + bio_reset(s->iop.bio, s->cache_miss->bi_bdev, REQ_OP_READ); + s->iop.bio->bi_iter.bi_sector = + s->cache_miss->bi_iter.bi_sector; + s->iop.bio->bi_iter.bi_size = s->insert_bio_sectors << 9; + bio_clone_blkg_association(s->iop.bio, s->cache_miss); + bch_bio_map(s->iop.bio, NULL); - src_offset = src->bv_offset; - } - - bytes = min(dst->bv_offset + dst->bv_len - dst_offset, - src->bv_offset + src->bv_len - src_offset); - - memcpy(dst_ptr + dst_offset, - page_address(src->bv_page) + src_offset, - bytes); - - src_offset += bytes; - dst_offset += bytes; - } + 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->recoverable && !s->read_dirty_data) + bch_data_verify(dc, s->orig_bio); + closure_get(&dc->disk.cl); bio_complete(s); - if (s->op.cache_bio && - !test_bit(CACHE_SET_STOPPING, &s->op.c->flags)) { - s->op.type = BTREE_REPLACE; - closure_call(&s->op.cl, bch_insert_data, 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_read_complete, NULL); + continue_at(cl, cached_dev_cache_miss_done, NULL); } -static void request_read_done_bh(struct closure *cl) +static CLOSURE_CALLBACK(cached_dev_read_done_bh) { - struct search *s = container_of(cl, struct search, cl); + closure_type(s, struct search, cl); struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); - bch_mark_cache_accounting(s, !s->cache_miss, s->op.skip); + bch_mark_cache_accounting(s->iop.c, s->d, + !s->cache_missed, s->iop.bypass); + trace_bcache_read(s->orig_bio, !s->cache_missed, s->iop.bypass); - if (s->error) - continue_at_nobarrier(cl, request_read_error, bcache_wq); - else if (s->op.cache_bio || verify(dc, &s->bio.bio)) - continue_at_nobarrier(cl, request_read_done, bcache_wq); + if (s->iop.status) + continue_at_nobarrier(cl, cached_dev_read_error, bcache_wq); + else if (s->iop.bio || verify(dc)) + continue_at_nobarrier(cl, cached_dev_read_done, bcache_wq); else - continue_at_nobarrier(cl, cached_dev_read_complete, NULL); + continue_at_nobarrier(cl, cached_dev_bio_complete, NULL); } static int cached_dev_cache_miss(struct btree *b, struct search *s, - struct bio *bio, unsigned sectors) + struct bio *bio, unsigned int sectors) { - int ret = 0; - unsigned reada; + int ret = MAP_CONTINUE; struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); - struct bio *miss; + struct bio *miss, *cache_bio; + unsigned int size_limit; - miss = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split); - if (!miss) - return -EAGAIN; + s->cache_missed = 1; - if (miss == bio) - s->op.lookup_done = true; - - miss->bi_end_io = request_endio; - miss->bi_private = &s->cl; - - if (s->cache_miss || s->op.skip) + if (s->cache_miss || s->iop.bypass) { + miss = bio_next_split(bio, sectors, GFP_NOIO, &s->d->bio_split); + ret = miss == bio ? MAP_DONE : MAP_CONTINUE; goto out_submit; - - if (miss != bio || - (bio->bi_rw & REQ_RAHEAD) || - (bio->bi_rw & REQ_META) || - s->op.c->gc_stats.in_use >= CUTOFF_CACHE_READA) - reada = 0; - else { - reada = min(dc->readahead >> 9, - sectors - bio_sectors(miss)); - - if (bio_end(miss) + reada > bdev_sectors(miss->bi_bdev)) - reada = bdev_sectors(miss->bi_bdev) - bio_end(miss); } - s->cache_bio_sectors = bio_sectors(miss) + reada; - s->op.cache_bio = bio_alloc_bioset(GFP_NOWAIT, - DIV_ROUND_UP(s->cache_bio_sectors, PAGE_SECTORS), - dc->disk.bio_split); + /* Limitation for valid replace key size and cache_bio bvecs number */ + size_limit = min_t(unsigned int, BIO_MAX_VECS * PAGE_SECTORS, + (1 << KEY_SIZE_BITS) - 1); + s->insert_bio_sectors = min3(size_limit, sectors, bio_sectors(bio)); - if (!s->op.cache_bio) - goto out_submit; + s->iop.replace_key = KEY(s->iop.inode, + bio->bi_iter.bi_sector + s->insert_bio_sectors, + s->insert_bio_sectors); - s->op.cache_bio->bi_sector = miss->bi_sector; - s->op.cache_bio->bi_bdev = miss->bi_bdev; - s->op.cache_bio->bi_size = s->cache_bio_sectors << 9; + ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key); + if (ret) + return ret; - s->op.cache_bio->bi_end_io = request_endio; - s->op.cache_bio->bi_private = &s->cl; + s->iop.replace = true; + + miss = bio_next_split(bio, s->insert_bio_sectors, GFP_NOIO, + &s->d->bio_split); /* btree_search_recurse()'s btree iterator is no good anymore */ - ret = -EINTR; - if (!bch_btree_insert_check_key(b, &s->op, s->op.cache_bio)) - goto out_put; + ret = miss == bio ? MAP_DONE : -EINTR; - bch_bio_map(s->op.cache_bio, NULL); - if (bch_bio_alloc_pages(s->op.cache_bio, __GFP_NOWARN|GFP_NOIO)) - goto out_put; + cache_bio = bio_alloc_bioset(miss->bi_bdev, + DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS), + 0, GFP_NOWAIT, &dc->disk.bio_split); + if (!cache_bio) + goto out_submit; - s->cache_miss = miss; - bio_get(s->op.cache_bio); + cache_bio->bi_iter.bi_sector = miss->bi_iter.bi_sector; + cache_bio->bi_iter.bi_size = s->insert_bio_sectors << 9; - trace_bcache_cache_miss(s->orig_bio); - closure_bio_submit(s->op.cache_bio, &s->cl, s->d); + cache_bio->bi_end_io = backing_request_endio; + cache_bio->bi_private = &s->cl; + + bch_bio_map(cache_bio, NULL); + if (bch_bio_alloc_pages(cache_bio, __GFP_NOWARN|GFP_NOIO)) + goto out_put; + + s->cache_miss = miss; + s->iop.bio = cache_bio; + bio_get(cache_bio); + /* I/O request sent to backing device */ + closure_bio_submit(s->iop.c, cache_bio, &s->cl); return ret; out_put: - bio_put(s->op.cache_bio); - s->op.cache_bio = NULL; + bio_put(cache_bio); out_submit: - closure_bio_submit(miss, &s->cl, s->d); + miss->bi_end_io = backing_request_endio; + miss->bi_private = &s->cl; + /* I/O request sent to backing device */ + closure_bio_submit(s->iop.c, miss, &s->cl); return ret; } -static void request_read(struct cached_dev *dc, struct search *s) +static void cached_dev_read(struct cached_dev *dc, struct search *s) { struct closure *cl = &s->cl; - check_should_skip(dc, s); - closure_call(&s->op.cl, btree_read_async, NULL, cl); - - continue_at(cl, request_read_done_bh, NULL); + closure_call(&s->iop.cl, cache_lookup, NULL, cl); + continue_at(cl, cached_dev_read_done_bh, NULL); } /* Process writes */ -static void cached_dev_write_complete(struct closure *cl) +static CLOSURE_CALLBACK(cached_dev_write_complete) { - struct search *s = container_of(cl, struct search, cl); + closure_type(s, 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 bool should_writeback(struct cached_dev *dc, struct bio *bio) -{ - unsigned threshold = (bio->bi_rw & REQ_SYNC) - ? CUTOFF_WRITEBACK_SYNC - : CUTOFF_WRITEBACK; - - return !atomic_read(&dc->disk.detaching) && - cache_mode(dc, bio) == CACHE_MODE_WRITEBACK && - dc->disk.c->gc_stats.in_use < threshold; + cached_dev_bio_complete(&cl->work); } -static void request_write(struct cached_dev *dc, struct search *s) +static void cached_dev_write(struct cached_dev *dc, struct search *s) { struct closure *cl = &s->cl; struct bio *bio = &s->bio.bio; - struct bkey start, end; - start = KEY(dc->disk.id, bio->bi_sector, 0); - end = KEY(dc->disk.id, bio_end(bio), 0); + struct bkey start = KEY(dc->disk.id, bio->bi_iter.bi_sector, 0); + struct bkey end = KEY(dc->disk.id, bio_end_sector(bio), 0); - bch_keybuf_check_overlapping(&s->op.c->moving_gc_keys, &start, &end); + bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys, &start, &end); - check_should_skip(dc, s); down_read_non_owner(&dc->writeback_lock); - if (bch_keybuf_check_overlapping(&dc->writeback_keys, &start, &end)) { - s->op.skip = false; - s->writeback = true; + /* + * We overlap with some dirty data undergoing background + * writeback, force this write to writeback + */ + s->iop.bypass = false; + s->iop.writeback = true; } - if (bio->bi_rw & REQ_DISCARD) - goto skip; - - if (s->op.skip) - goto skip; - - if (should_writeback(dc, s->orig_bio)) - s->writeback = true; - - if (!s->writeback) { - s->op.cache_bio = bio_clone_bioset(bio, GFP_NOIO, - dc->disk.bio_split); + /* + * 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) + s->iop.bypass = true; + + if (should_writeback(dc, s->orig_bio, + cache_mode(dc), + s->iop.bypass)) { + s->iop.bypass = false; + s->iop.writeback = true; + } - trace_bcache_writethrough(s->orig_bio); - closure_bio_submit(bio, cl, s->d); + if (s->iop.bypass) { + s->iop.bio = s->orig_bio; + bio_get(s->iop.bio); + + if (bio_op(bio) == REQ_OP_DISCARD && + !bdev_max_discard_sectors(dc->bdev)) + goto insert_data; + + /* I/O request sent to backing device */ + bio->bi_end_io = backing_request_endio; + closure_bio_submit(s->iop.c, bio, cl); + + } else if (s->iop.writeback) { + bch_writeback_add(dc); + s->iop.bio = bio; + + if (bio->bi_opf & REQ_PREFLUSH) { + /* + * Also need to send a flush to the backing + * device. + */ + struct bio *flush; + + flush = bio_alloc_bioset(bio->bi_bdev, 0, + REQ_OP_WRITE | REQ_PREFLUSH, + GFP_NOIO, &dc->disk.bio_split); + if (!flush) { + s->iop.status = BLK_STS_RESOURCE; + goto insert_data; + } + flush->bi_end_io = backing_request_endio; + flush->bi_private = cl; + /* I/O request sent to backing device */ + closure_bio_submit(s->iop.c, flush, cl); + } } else { - s->op.cache_bio = bio; - trace_bcache_writeback(s->orig_bio); - bch_writeback_add(dc, bio_sectors(bio)); + s->iop.bio = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO, + &dc->disk.bio_split); + /* I/O request sent to backing device */ + bio->bi_end_io = backing_request_endio; + closure_bio_submit(s->iop.c, bio, cl); } -out: - closure_call(&s->op.cl, bch_insert_data, NULL, cl); - continue_at(cl, cached_dev_write_complete, NULL); -skip: - s->op.skip = true; - s->op.cache_bio = s->orig_bio; - bio_get(s->op.cache_bio); - trace_bcache_write_skip(s->orig_bio); - if ((bio->bi_rw & REQ_DISCARD) && - !blk_queue_discard(bdev_get_queue(dc->bdev))) - goto out; - - closure_bio_submit(bio, cl, s->d); - goto out; +insert_data: + closure_call(&s->iop.cl, bch_data_insert, NULL, cl); + continue_at(cl, cached_dev_write_complete, NULL); } -static void request_nodata(struct cached_dev *dc, struct search *s) +static CLOSURE_CALLBACK(cached_dev_nodata) { - struct closure *cl = &s->cl; + closure_type(s, struct search, cl); struct bio *bio = &s->bio.bio; - if (bio->bi_rw & REQ_DISCARD) { - request_write(dc, s); - return; - } - - if (s->op.flush_journal) - bch_journal_meta(s->op.c, cl); + if (s->iop.flush_journal) + bch_journal_meta(s->iop.c, cl); - closure_bio_submit(bio, cl, s->d); + /* If it's a flush, we send the flush to the backing device too */ + bio->bi_end_io = backing_request_endio; + closure_bio_submit(s->iop.c, bio, cl); continue_at(cl, cached_dev_bio_complete, NULL); } -/* Cached devices - read & write stuff */ +struct detached_dev_io_private { + struct bcache_device *d; + unsigned long start_time; + bio_end_io_t *bi_end_io; + void *bi_private; + struct block_device *orig_bdev; +}; -int bch_get_congested(struct cache_set *c) +static void detached_dev_end_io(struct bio *bio) { - int i; + struct detached_dev_io_private *ddip; - if (!c->congested_read_threshold_us && - !c->congested_write_threshold_us) - return 0; + ddip = bio->bi_private; + bio->bi_end_io = ddip->bi_end_io; + bio->bi_private = ddip->bi_private; - i = (local_clock_us() - c->congested_last_us) / 1024; - if (i < 0) - return 0; + /* Count on the bcache device */ + bio_end_io_acct_remapped(bio, ddip->start_time, ddip->orig_bdev); - i += atomic_read(&c->congested); - if (i >= 0) - return 0; - - i += CONGESTED_MAX; + if (bio->bi_status) { + struct cached_dev *dc = container_of(ddip->d, + struct cached_dev, disk); + /* should count I/O error for backing device here */ + bch_count_backing_io_errors(dc, bio); + } - return i <= 0 ? 1 : fract_exp_two(i, 6); + kfree(ddip); + bio->bi_end_io(bio); } -static void add_sequential(struct task_struct *t) +static void detached_dev_do_request(struct bcache_device *d, struct bio *bio, + struct block_device *orig_bdev, unsigned long start_time) { - ewma_add(t->sequential_io_avg, - t->sequential_io, 8, 0); + struct detached_dev_io_private *ddip; + struct cached_dev *dc = container_of(d, struct cached_dev, disk); - t->sequential_io = 0; -} + /* + * no need to call closure_get(&dc->disk.cl), + * because upper layer had already opened bcache device, + * which would call closure_get(&dc->disk.cl) + */ + ddip = kzalloc(sizeof(struct detached_dev_io_private), GFP_NOIO); + if (!ddip) { + bio->bi_status = BLK_STS_RESOURCE; + bio->bi_end_io(bio); + return; + } -static struct hlist_head *iohash(struct cached_dev *dc, uint64_t k) -{ - return &dc->io_hash[hash_64(k, RECENT_IO_BITS)]; + ddip->d = d; + /* Count on the bcache device */ + ddip->orig_bdev = orig_bdev; + ddip->start_time = start_time; + ddip->bi_end_io = bio->bi_end_io; + ddip->bi_private = bio->bi_private; + bio->bi_end_io = detached_dev_end_io; + bio->bi_private = ddip; + + if ((bio_op(bio) == REQ_OP_DISCARD) && + !bdev_max_discard_sectors(dc->bdev)) + bio->bi_end_io(bio); + else + submit_bio_noacct(bio); } -static void check_should_skip(struct cached_dev *dc, struct search *s) +static void quit_max_writeback_rate(struct cache_set *c, + struct cached_dev *this_dc) { - struct cache_set *c = s->op.c; - struct bio *bio = &s->bio.bio; - - long rand; - int cutoff = bch_get_congested(c); - unsigned mode = cache_mode(dc, bio); - - 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; + int i; + struct bcache_device *d; + struct cached_dev *dc; - if (bio->bi_sector & (c->sb.block_size - 1) || - bio_sectors(bio) & (c->sb.block_size - 1)) { - pr_debug("skipping unaligned io"); - goto skip; - } + /* + * mutex bch_register_lock may compete with other parallel requesters, + * or attach/detach operations on other backing device. Waiting to + * the mutex lock may increase I/O request latency for seconds or more. + * To avoid such situation, if mutext_trylock() failed, only writeback + * rate of current cached device is set to 1, and __update_write_back() + * will decide writeback rate of other cached devices (remember now + * c->idle_counter is 0 already). + */ + if (mutex_trylock(&bch_register_lock)) { + for (i = 0; i < c->devices_max_used; i++) { + if (!c->devices[i]) + continue; + + if (UUID_FLASH_ONLY(&c->uuids[i])) + continue; + + d = c->devices[i]; + dc = container_of(d, struct cached_dev, disk); + /* + * set writeback rate to default minimum value, + * then let update_writeback_rate() to decide the + * upcoming rate. + */ + atomic_long_set(&dc->writeback_rate.rate, 1); + } + mutex_unlock(&bch_register_lock); + } else + atomic_long_set(&this_dc->writeback_rate.rate, 1); +} - if (!cutoff) { - cutoff = dc->sequential_cutoff >> 9; +/* Cached devices - read & write stuff */ - if (!cutoff) - goto rescale; +void cached_dev_submit_bio(struct bio *bio) +{ + struct search *s; + struct block_device *orig_bdev = bio->bi_bdev; + struct bcache_device *d = orig_bdev->bd_disk->private_data; + struct cached_dev *dc = container_of(d, struct cached_dev, disk); + unsigned long start_time; + int rw = bio_data_dir(bio); - if (mode == CACHE_MODE_WRITEBACK && - (bio->bi_rw & REQ_WRITE) && - (bio->bi_rw & REQ_SYNC)) - goto rescale; + if (unlikely((d->c && test_bit(CACHE_SET_IO_DISABLE, &d->c->flags)) || + dc->io_disable)) { + bio->bi_status = BLK_STS_IOERR; + bio_endio(bio); + return; } - 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(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); + if (likely(d->c)) { + if (atomic_read(&d->c->idle_counter)) + atomic_set(&d->c->idle_counter, 0); + /* + * If at_max_writeback_rate of cache set is true and new I/O + * comes, quit max writeback rate of all cached devices + * attached to this cache set, and set at_max_writeback_rate + * to false. + */ + if (unlikely(atomic_read(&d->c->at_max_writeback_rate) == 1)) { + atomic_set(&d->c->at_max_writeback_rate, 0); + quit_max_writeback_rate(d->c, dc); + } } - rand = get_random_int(); - cutoff -= bitmap_weight(&rand, BITS_PER_LONG); - - if (cutoff <= (int) (max(s->task->sequential_io, - s->task->sequential_io_avg) >> 9)) - goto skip; + start_time = bio_start_io_acct(bio); -rescale: - bch_rescale_priorities(c, bio_sectors(bio)); - return; -skip: - bch_mark_sectors_bypassed(s, bio_sectors(bio)); - s->op.skip = true; -} - -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 cpu, rw = bio_data_dir(bio); - - cpu = part_stat_lock(); - part_stat_inc(cpu, &d->disk->part0, ios[rw]); - part_stat_add(cpu, &d->disk->part0, sectors[rw], bio_sectors(bio)); - part_stat_unlock(); - - bio->bi_bdev = dc->bdev; - bio->bi_sector += dc->sb.data_offset; + bio_set_dev(bio, dc->bdev); + bio->bi_iter.bi_sector += dc->sb.data_offset; if (cached_dev_get(dc)) { - s = search_alloc(bio, d); - trace_bcache_request_start(s, bio); - - if (!bio_has_data(bio)) - request_nodata(dc, s); - else if (rw) - request_write(dc, s); - else - request_read(dc, s); - } else { - if ((bio->bi_rw & REQ_DISCARD) && - !blk_queue_discard(bdev_get_queue(dc->bdev))) - bio_endio(bio, 0); - else - bch_generic_make_request(bio, &d->bio_split_hook); - } + s = search_alloc(bio, d, orig_bdev, start_time); + trace_bcache_request_start(s->d, bio); + + if (!bio->bi_iter.bi_size) { + /* + * can't call bch_journal_meta from under + * submit_bio_noacct + */ + continue_at_nobarrier(&s->cl, + cached_dev_nodata, + bcache_wq); + } else { + s->iop.bypass = check_should_bypass(dc, bio); + + if (rw) + cached_dev_write(dc, s); + else + cached_dev_read(dc, s); + } + } else + /* I/O request sent to backing device */ + detached_dev_do_request(d, bio, orig_bdev, start_time); } -static int cached_dev_ioctl(struct bcache_device *d, fmode_t mode, +static int cached_dev_ioctl(struct bcache_device *d, blk_mode_t mode, unsigned int cmd, unsigned long arg) { struct cached_dev *dc = container_of(d, struct cached_dev, disk); - return __blkdev_driver_ioctl(dc->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->bdev); - int ret = 0; - - if (bdi_congested(&q->backing_dev_info, bits)) - return 1; - - if (cached_dev_get(dc)) { - unsigned i; - struct cache *ca; - - for_each_cache(ca, d->c, i) { - q = bdev_get_queue(ca->bdev); - ret |= bdi_congested(&q->backing_dev_info, bits); - } - cached_dev_put(dc); - } - - return ret; + if (dc->io_disable) + return -EIO; + if (!dc->bdev->bd_disk->fops->ioctl) + return -ENOTTY; + return dc->bdev->bd_disk->fops->ioctl(dc->bdev, mode, cmd, arg); } 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.cache_miss = cached_dev_cache_miss; dc->disk.ioctl = cached_dev_ioctl; } @@ -1286,113 +1263,90 @@ void bch_cached_dev_request_init(struct cached_dev *dc) /* Flash backed devices */ static int flash_dev_cache_miss(struct btree *b, struct search *s, - struct bio *bio, unsigned sectors) + struct bio *bio, unsigned int sectors) { - /* Zero fill bio */ + unsigned int bytes = min(sectors, bio_sectors(bio)) << 9; - while (bio->bi_idx != bio->bi_vcnt) { - struct bio_vec *bv = bio_iovec(bio); - unsigned j = min(bv->bv_len >> 9, sectors); + swap(bio->bi_iter.bi_size, bytes); + zero_fill_bio(bio); + swap(bio->bi_iter.bi_size, bytes); - void *p = kmap(bv->bv_page); - memset(p + bv->bv_offset, 0, j << 9); - kunmap(bv->bv_page); + bio_advance(bio, bytes); - bv->bv_len -= j << 9; - bv->bv_offset += j << 9; + if (!bio->bi_iter.bi_size) + return MAP_DONE; - if (bv->bv_len) - return 0; - - bio->bi_sector += j; - bio->bi_size -= j << 9; + return MAP_CONTINUE; +} - bio->bi_idx++; - sectors -= j; - } +static CLOSURE_CALLBACK(flash_dev_nodata) +{ + closure_type(s, struct search, cl); - s->op.lookup_done = true; + if (s->iop.flush_journal) + bch_journal_meta(s->iop.c, cl); - return 0; + continue_at(cl, search_free, NULL); } -static void flash_dev_make_request(struct request_queue *q, struct bio *bio) +void flash_dev_submit_bio(struct bio *bio) { struct search *s; struct closure *cl; struct bcache_device *d = bio->bi_bdev->bd_disk->private_data; - int cpu, rw = bio_data_dir(bio); - cpu = part_stat_lock(); - part_stat_inc(cpu, &d->disk->part0, ios[rw]); - part_stat_add(cpu, &d->disk->part0, sectors[rw], bio_sectors(bio)); - part_stat_unlock(); + if (unlikely(d->c && test_bit(CACHE_SET_IO_DISABLE, &d->c->flags))) { + bio->bi_status = BLK_STS_IOERR; + bio_endio(bio); + return; + } - s = search_alloc(bio, d); + s = search_alloc(bio, d, bio->bi_bdev, bio_start_io_acct(bio)); cl = &s->cl; bio = &s->bio.bio; - trace_bcache_request_start(s, bio); + trace_bcache_request_start(s->d, bio); - if (bio_has_data(bio) && !rw) { - closure_call(&s->op.cl, btree_read_async, NULL, cl); - } else if (bio_has_data(bio) || s->op.skip) { - bch_keybuf_check_overlapping(&s->op.c->moving_gc_keys, - &KEY(d->id, bio->bi_sector, 0), - &KEY(d->id, bio_end(bio), 0)); + if (!bio->bi_iter.bi_size) { + /* + * can't call bch_journal_meta from under submit_bio_noacct + */ + continue_at_nobarrier(&s->cl, + flash_dev_nodata, + bcache_wq); + return; + } else if (bio_data_dir(bio)) { + bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys, + &KEY(d->id, bio->bi_iter.bi_sector, 0), + &KEY(d->id, bio_end_sector(bio), 0)); - s->writeback = true; - s->op.cache_bio = bio; + s->iop.bypass = (bio_op(bio) == REQ_OP_DISCARD) != 0; + s->iop.writeback = true; + s->iop.bio = bio; - closure_call(&s->op.cl, bch_insert_data, NULL, cl); + closure_call(&s->iop.cl, bch_data_insert, NULL, cl); } else { - /* No data - probably a cache flush */ - if (s->op.flush_journal) - bch_journal_meta(s->op.c, cl); + closure_call(&s->iop.cl, cache_lookup, NULL, cl); } continue_at(cl, search_free, NULL); } -static int flash_dev_ioctl(struct bcache_device *d, fmode_t mode, +static int flash_dev_ioctl(struct bcache_device *d, blk_mode_t mode, unsigned int cmd, unsigned long arg) { return -ENOTTY; } -static int flash_dev_congested(void *data, int bits) -{ - struct bcache_device *d = data; - struct request_queue *q; - struct cache *ca; - unsigned i; - int ret = 0; - - for_each_cache(ca, d->c, i) { - q = bdev_get_queue(ca->bdev); - ret |= bdi_congested(&q->backing_dev_info, bits); - } - - return ret; -} - void bch_flash_dev_request_init(struct bcache_device *d) { - struct gendisk *g = d->disk; - - g->queue->make_request_fn = flash_dev_make_request; - g->queue->backing_dev_info.congested_fn = flash_dev_congested; d->cache_miss = flash_dev_cache_miss; d->ioctl = flash_dev_ioctl; } void bch_request_exit(void) { -#ifdef CONFIG_CGROUP_BCACHE - cgroup_unload_subsys(&bcache_subsys); -#endif - if (bch_search_cache) - kmem_cache_destroy(bch_search_cache); + kmem_cache_destroy(bch_search_cache); } int __init bch_request_init(void) @@ -1401,11 +1355,5 @@ int __init bch_request_init(void) if (!bch_search_cache) return -ENOMEM; -#ifdef CONFIG_CGROUP_BCACHE - cgroup_load_subsys(&bcache_subsys); - init_bch_cgroup(&bcache_default_cgroup); - - cgroup_add_cftypes(&bcache_subsys, bch_files); -#endif return 0; } |