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![Coly Li](/assets/img/avatar_default.png)
The local variables check_state (in bch_btree_check()) and state (in bch_sectors_dirty_init()) should be fully filled by 0, because before allocating them on stack, they were dynamically allocated by kzalloc(). Signed-off-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20220527152818.27545-2-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2780 lines
63 KiB
C
2780 lines
63 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2010 Kent Overstreet <kent.overstreet@gmail.com>
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*
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* Uses a block device as cache for other block devices; optimized for SSDs.
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* All allocation is done in buckets, which should match the erase block size
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* of the device.
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*
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* Buckets containing cached data are kept on a heap sorted by priority;
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* bucket priority is increased on cache hit, and periodically all the buckets
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* on the heap have their priority scaled down. This currently is just used as
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* an LRU but in the future should allow for more intelligent heuristics.
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*
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* Buckets have an 8 bit counter; freeing is accomplished by incrementing the
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* counter. Garbage collection is used to remove stale pointers.
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*
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* Indexing is done via a btree; nodes are not necessarily fully sorted, rather
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* as keys are inserted we only sort the pages that have not yet been written.
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* When garbage collection is run, we resort the entire node.
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*
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* All configuration is done via sysfs; see Documentation/admin-guide/bcache.rst.
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*/
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#include "bcache.h"
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#include "btree.h"
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#include "debug.h"
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#include "extents.h"
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#include <linux/slab.h>
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#include <linux/bitops.h>
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#include <linux/hash.h>
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#include <linux/kthread.h>
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#include <linux/prefetch.h>
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#include <linux/random.h>
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#include <linux/rcupdate.h>
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#include <linux/sched/clock.h>
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#include <linux/rculist.h>
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#include <linux/delay.h>
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#include <trace/events/bcache.h>
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/*
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* Todo:
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* register_bcache: Return errors out to userspace correctly
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*
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* Writeback: don't undirty key until after a cache flush
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*
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* Create an iterator for key pointers
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*
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* On btree write error, mark bucket such that it won't be freed from the cache
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*
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* Journalling:
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* Check for bad keys in replay
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* Propagate barriers
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* Refcount journal entries in journal_replay
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*
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* Garbage collection:
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* Finish incremental gc
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* Gc should free old UUIDs, data for invalid UUIDs
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*
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* Provide a way to list backing device UUIDs we have data cached for, and
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* probably how long it's been since we've seen them, and a way to invalidate
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* dirty data for devices that will never be attached again
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*
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* Keep 1 min/5 min/15 min statistics of how busy a block device has been, so
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* that based on that and how much dirty data we have we can keep writeback
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* from being starved
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*
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* Add a tracepoint or somesuch to watch for writeback starvation
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*
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* When btree depth > 1 and splitting an interior node, we have to make sure
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* alloc_bucket() cannot fail. This should be true but is not completely
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* obvious.
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*
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* Plugging?
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*
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* If data write is less than hard sector size of ssd, round up offset in open
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* bucket to the next whole sector
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*
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* Superblock needs to be fleshed out for multiple cache devices
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*
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* Add a sysfs tunable for the number of writeback IOs in flight
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*
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* Add a sysfs tunable for the number of open data buckets
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*
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* IO tracking: Can we track when one process is doing io on behalf of another?
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* IO tracking: Don't use just an average, weigh more recent stuff higher
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*
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* Test module load/unload
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*/
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#define MAX_NEED_GC 64
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#define MAX_SAVE_PRIO 72
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#define MAX_GC_TIMES 100
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#define MIN_GC_NODES 100
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#define GC_SLEEP_MS 100
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#define PTR_DIRTY_BIT (((uint64_t) 1 << 36))
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#define PTR_HASH(c, k) \
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(((k)->ptr[0] >> c->bucket_bits) | PTR_GEN(k, 0))
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static struct workqueue_struct *btree_io_wq;
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#define insert_lock(s, b) ((b)->level <= (s)->lock)
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static inline struct bset *write_block(struct btree *b)
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{
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return ((void *) btree_bset_first(b)) + b->written * block_bytes(b->c->cache);
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}
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static void bch_btree_init_next(struct btree *b)
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{
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/* If not a leaf node, always sort */
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if (b->level && b->keys.nsets)
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bch_btree_sort(&b->keys, &b->c->sort);
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else
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bch_btree_sort_lazy(&b->keys, &b->c->sort);
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if (b->written < btree_blocks(b))
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bch_bset_init_next(&b->keys, write_block(b),
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bset_magic(&b->c->cache->sb));
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}
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/* Btree key manipulation */
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void bkey_put(struct cache_set *c, struct bkey *k)
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{
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unsigned int i;
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for (i = 0; i < KEY_PTRS(k); i++)
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if (ptr_available(c, k, i))
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atomic_dec_bug(&PTR_BUCKET(c, k, i)->pin);
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}
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/* Btree IO */
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static uint64_t btree_csum_set(struct btree *b, struct bset *i)
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{
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uint64_t crc = b->key.ptr[0];
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void *data = (void *) i + 8, *end = bset_bkey_last(i);
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crc = crc64_be(crc, data, end - data);
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return crc ^ 0xffffffffffffffffULL;
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}
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void bch_btree_node_read_done(struct btree *b)
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{
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const char *err = "bad btree header";
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struct bset *i = btree_bset_first(b);
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struct btree_iter *iter;
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/*
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* c->fill_iter can allocate an iterator with more memory space
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* than static MAX_BSETS.
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* See the comment arount cache_set->fill_iter.
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*/
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iter = mempool_alloc(&b->c->fill_iter, GFP_NOIO);
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iter->size = b->c->cache->sb.bucket_size / b->c->cache->sb.block_size;
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iter->used = 0;
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#ifdef CONFIG_BCACHE_DEBUG
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iter->b = &b->keys;
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#endif
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if (!i->seq)
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goto err;
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for (;
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b->written < btree_blocks(b) && i->seq == b->keys.set[0].data->seq;
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i = write_block(b)) {
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err = "unsupported bset version";
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if (i->version > BCACHE_BSET_VERSION)
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goto err;
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err = "bad btree header";
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if (b->written + set_blocks(i, block_bytes(b->c->cache)) >
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btree_blocks(b))
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goto err;
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err = "bad magic";
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if (i->magic != bset_magic(&b->c->cache->sb))
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goto err;
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err = "bad checksum";
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switch (i->version) {
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case 0:
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if (i->csum != csum_set(i))
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goto err;
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break;
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case BCACHE_BSET_VERSION:
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if (i->csum != btree_csum_set(b, i))
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goto err;
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break;
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}
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err = "empty set";
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if (i != b->keys.set[0].data && !i->keys)
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goto err;
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bch_btree_iter_push(iter, i->start, bset_bkey_last(i));
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b->written += set_blocks(i, block_bytes(b->c->cache));
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}
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err = "corrupted btree";
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for (i = write_block(b);
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bset_sector_offset(&b->keys, i) < KEY_SIZE(&b->key);
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i = ((void *) i) + block_bytes(b->c->cache))
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if (i->seq == b->keys.set[0].data->seq)
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goto err;
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bch_btree_sort_and_fix_extents(&b->keys, iter, &b->c->sort);
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i = b->keys.set[0].data;
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err = "short btree key";
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if (b->keys.set[0].size &&
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bkey_cmp(&b->key, &b->keys.set[0].end) < 0)
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goto err;
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if (b->written < btree_blocks(b))
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bch_bset_init_next(&b->keys, write_block(b),
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bset_magic(&b->c->cache->sb));
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out:
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mempool_free(iter, &b->c->fill_iter);
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return;
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err:
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set_btree_node_io_error(b);
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bch_cache_set_error(b->c, "%s at bucket %zu, block %u, %u keys",
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err, PTR_BUCKET_NR(b->c, &b->key, 0),
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bset_block_offset(b, i), i->keys);
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goto out;
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}
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static void btree_node_read_endio(struct bio *bio)
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{
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struct closure *cl = bio->bi_private;
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closure_put(cl);
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}
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static void bch_btree_node_read(struct btree *b)
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{
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uint64_t start_time = local_clock();
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struct closure cl;
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struct bio *bio;
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trace_bcache_btree_read(b);
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closure_init_stack(&cl);
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bio = bch_bbio_alloc(b->c);
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bio->bi_iter.bi_size = KEY_SIZE(&b->key) << 9;
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bio->bi_end_io = btree_node_read_endio;
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bio->bi_private = &cl;
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bio->bi_opf = REQ_OP_READ | REQ_META;
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bch_bio_map(bio, b->keys.set[0].data);
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bch_submit_bbio(bio, b->c, &b->key, 0);
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closure_sync(&cl);
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if (bio->bi_status)
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set_btree_node_io_error(b);
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bch_bbio_free(bio, b->c);
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if (btree_node_io_error(b))
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goto err;
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bch_btree_node_read_done(b);
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bch_time_stats_update(&b->c->btree_read_time, start_time);
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return;
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err:
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bch_cache_set_error(b->c, "io error reading bucket %zu",
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PTR_BUCKET_NR(b->c, &b->key, 0));
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}
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static void btree_complete_write(struct btree *b, struct btree_write *w)
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{
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if (w->prio_blocked &&
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!atomic_sub_return(w->prio_blocked, &b->c->prio_blocked))
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wake_up_allocators(b->c);
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if (w->journal) {
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atomic_dec_bug(w->journal);
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__closure_wake_up(&b->c->journal.wait);
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}
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w->prio_blocked = 0;
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w->journal = NULL;
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}
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static void btree_node_write_unlock(struct closure *cl)
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{
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struct btree *b = container_of(cl, struct btree, io);
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up(&b->io_mutex);
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}
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static void __btree_node_write_done(struct closure *cl)
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{
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struct btree *b = container_of(cl, struct btree, io);
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struct btree_write *w = btree_prev_write(b);
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bch_bbio_free(b->bio, b->c);
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b->bio = NULL;
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btree_complete_write(b, w);
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if (btree_node_dirty(b))
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queue_delayed_work(btree_io_wq, &b->work, 30 * HZ);
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closure_return_with_destructor(cl, btree_node_write_unlock);
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}
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static void btree_node_write_done(struct closure *cl)
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{
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struct btree *b = container_of(cl, struct btree, io);
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bio_free_pages(b->bio);
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__btree_node_write_done(cl);
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}
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static void btree_node_write_endio(struct bio *bio)
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{
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struct closure *cl = bio->bi_private;
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struct btree *b = container_of(cl, struct btree, io);
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if (bio->bi_status)
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set_btree_node_io_error(b);
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bch_bbio_count_io_errors(b->c, bio, bio->bi_status, "writing btree");
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closure_put(cl);
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}
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static void do_btree_node_write(struct btree *b)
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{
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struct closure *cl = &b->io;
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struct bset *i = btree_bset_last(b);
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BKEY_PADDED(key) k;
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i->version = BCACHE_BSET_VERSION;
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i->csum = btree_csum_set(b, i);
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BUG_ON(b->bio);
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b->bio = bch_bbio_alloc(b->c);
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b->bio->bi_end_io = btree_node_write_endio;
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b->bio->bi_private = cl;
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b->bio->bi_iter.bi_size = roundup(set_bytes(i), block_bytes(b->c->cache));
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b->bio->bi_opf = REQ_OP_WRITE | REQ_META | REQ_FUA;
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bch_bio_map(b->bio, i);
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/*
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* If we're appending to a leaf node, we don't technically need FUA -
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* this write just needs to be persisted before the next journal write,
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* which will be marked FLUSH|FUA.
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*
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* Similarly if we're writing a new btree root - the pointer is going to
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* be in the next journal entry.
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*
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* But if we're writing a new btree node (that isn't a root) or
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* appending to a non leaf btree node, we need either FUA or a flush
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* when we write the parent with the new pointer. FUA is cheaper than a
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* flush, and writes appending to leaf nodes aren't blocking anything so
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* just make all btree node writes FUA to keep things sane.
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*/
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bkey_copy(&k.key, &b->key);
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SET_PTR_OFFSET(&k.key, 0, PTR_OFFSET(&k.key, 0) +
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bset_sector_offset(&b->keys, i));
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if (!bch_bio_alloc_pages(b->bio, __GFP_NOWARN|GFP_NOWAIT)) {
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struct bio_vec *bv;
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void *addr = (void *) ((unsigned long) i & ~(PAGE_SIZE - 1));
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struct bvec_iter_all iter_all;
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bio_for_each_segment_all(bv, b->bio, iter_all) {
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memcpy(page_address(bv->bv_page), addr, PAGE_SIZE);
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addr += PAGE_SIZE;
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}
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bch_submit_bbio(b->bio, b->c, &k.key, 0);
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continue_at(cl, btree_node_write_done, NULL);
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} else {
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/*
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* No problem for multipage bvec since the bio is
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* just allocated
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*/
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b->bio->bi_vcnt = 0;
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bch_bio_map(b->bio, i);
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bch_submit_bbio(b->bio, b->c, &k.key, 0);
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closure_sync(cl);
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continue_at_nobarrier(cl, __btree_node_write_done, NULL);
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}
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}
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void __bch_btree_node_write(struct btree *b, struct closure *parent)
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{
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struct bset *i = btree_bset_last(b);
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lockdep_assert_held(&b->write_lock);
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trace_bcache_btree_write(b);
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BUG_ON(current->bio_list);
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BUG_ON(b->written >= btree_blocks(b));
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BUG_ON(b->written && !i->keys);
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BUG_ON(btree_bset_first(b)->seq != i->seq);
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bch_check_keys(&b->keys, "writing");
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cancel_delayed_work(&b->work);
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/* If caller isn't waiting for write, parent refcount is cache set */
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down(&b->io_mutex);
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closure_init(&b->io, parent ?: &b->c->cl);
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clear_bit(BTREE_NODE_dirty, &b->flags);
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change_bit(BTREE_NODE_write_idx, &b->flags);
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do_btree_node_write(b);
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atomic_long_add(set_blocks(i, block_bytes(b->c->cache)) * b->c->cache->sb.block_size,
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&b->c->cache->btree_sectors_written);
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b->written += set_blocks(i, block_bytes(b->c->cache));
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}
|
|
|
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void bch_btree_node_write(struct btree *b, struct closure *parent)
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{
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unsigned int nsets = b->keys.nsets;
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|
|
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lockdep_assert_held(&b->lock);
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|
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__bch_btree_node_write(b, parent);
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|
|
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/*
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* do verify if there was more than one set initially (i.e. we did a
|
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* sort) and we sorted down to a single set:
|
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*/
|
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if (nsets && !b->keys.nsets)
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bch_btree_verify(b);
|
|
|
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bch_btree_init_next(b);
|
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}
|
|
|
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static void bch_btree_node_write_sync(struct btree *b)
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|
{
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struct closure cl;
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|
|
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closure_init_stack(&cl);
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|
|
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mutex_lock(&b->write_lock);
|
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bch_btree_node_write(b, &cl);
|
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mutex_unlock(&b->write_lock);
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|
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closure_sync(&cl);
|
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}
|
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|
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static void btree_node_write_work(struct work_struct *w)
|
|
{
|
|
struct btree *b = container_of(to_delayed_work(w), struct btree, work);
|
|
|
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mutex_lock(&b->write_lock);
|
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if (btree_node_dirty(b))
|
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__bch_btree_node_write(b, NULL);
|
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mutex_unlock(&b->write_lock);
|
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}
|
|
|
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static void bch_btree_leaf_dirty(struct btree *b, atomic_t *journal_ref)
|
|
{
|
|
struct bset *i = btree_bset_last(b);
|
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struct btree_write *w = btree_current_write(b);
|
|
|
|
lockdep_assert_held(&b->write_lock);
|
|
|
|
BUG_ON(!b->written);
|
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BUG_ON(!i->keys);
|
|
|
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if (!btree_node_dirty(b))
|
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queue_delayed_work(btree_io_wq, &b->work, 30 * HZ);
|
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|
|
set_btree_node_dirty(b);
|
|
|
|
/*
|
|
* w->journal is always the oldest journal pin of all bkeys
|
|
* in the leaf node, to make sure the oldest jset seq won't
|
|
* be increased before this btree node is flushed.
|
|
*/
|
|
if (journal_ref) {
|
|
if (w->journal &&
|
|
journal_pin_cmp(b->c, w->journal, journal_ref)) {
|
|
atomic_dec_bug(w->journal);
|
|
w->journal = NULL;
|
|
}
|
|
|
|
if (!w->journal) {
|
|
w->journal = journal_ref;
|
|
atomic_inc(w->journal);
|
|
}
|
|
}
|
|
|
|
/* Force write if set is too big */
|
|
if (set_bytes(i) > PAGE_SIZE - 48 &&
|
|
!current->bio_list)
|
|
bch_btree_node_write(b, NULL);
|
|
}
|
|
|
|
/*
|
|
* Btree in memory cache - allocation/freeing
|
|
* mca -> memory cache
|
|
*/
|
|
|
|
#define mca_reserve(c) (((!IS_ERR_OR_NULL(c->root) && c->root->level) \
|
|
? c->root->level : 1) * 8 + 16)
|
|
#define mca_can_free(c) \
|
|
max_t(int, 0, c->btree_cache_used - mca_reserve(c))
|
|
|
|
static void mca_data_free(struct btree *b)
|
|
{
|
|
BUG_ON(b->io_mutex.count != 1);
|
|
|
|
bch_btree_keys_free(&b->keys);
|
|
|
|
b->c->btree_cache_used--;
|
|
list_move(&b->list, &b->c->btree_cache_freed);
|
|
}
|
|
|
|
static void mca_bucket_free(struct btree *b)
|
|
{
|
|
BUG_ON(btree_node_dirty(b));
|
|
|
|
b->key.ptr[0] = 0;
|
|
hlist_del_init_rcu(&b->hash);
|
|
list_move(&b->list, &b->c->btree_cache_freeable);
|
|
}
|
|
|
|
static unsigned int btree_order(struct bkey *k)
|
|
{
|
|
return ilog2(KEY_SIZE(k) / PAGE_SECTORS ?: 1);
|
|
}
|
|
|
|
static void mca_data_alloc(struct btree *b, struct bkey *k, gfp_t gfp)
|
|
{
|
|
if (!bch_btree_keys_alloc(&b->keys,
|
|
max_t(unsigned int,
|
|
ilog2(b->c->btree_pages),
|
|
btree_order(k)),
|
|
gfp)) {
|
|
b->c->btree_cache_used++;
|
|
list_move(&b->list, &b->c->btree_cache);
|
|
} else {
|
|
list_move(&b->list, &b->c->btree_cache_freed);
|
|
}
|
|
}
|
|
|
|
static struct btree *mca_bucket_alloc(struct cache_set *c,
|
|
struct bkey *k, gfp_t gfp)
|
|
{
|
|
/*
|
|
* kzalloc() is necessary here for initialization,
|
|
* see code comments in bch_btree_keys_init().
|
|
*/
|
|
struct btree *b = kzalloc(sizeof(struct btree), gfp);
|
|
|
|
if (!b)
|
|
return NULL;
|
|
|
|
init_rwsem(&b->lock);
|
|
lockdep_set_novalidate_class(&b->lock);
|
|
mutex_init(&b->write_lock);
|
|
lockdep_set_novalidate_class(&b->write_lock);
|
|
INIT_LIST_HEAD(&b->list);
|
|
INIT_DELAYED_WORK(&b->work, btree_node_write_work);
|
|
b->c = c;
|
|
sema_init(&b->io_mutex, 1);
|
|
|
|
mca_data_alloc(b, k, gfp);
|
|
return b;
|
|
}
|
|
|
|
static int mca_reap(struct btree *b, unsigned int min_order, bool flush)
|
|
{
|
|
struct closure cl;
|
|
|
|
closure_init_stack(&cl);
|
|
lockdep_assert_held(&b->c->bucket_lock);
|
|
|
|
if (!down_write_trylock(&b->lock))
|
|
return -ENOMEM;
|
|
|
|
BUG_ON(btree_node_dirty(b) && !b->keys.set[0].data);
|
|
|
|
if (b->keys.page_order < min_order)
|
|
goto out_unlock;
|
|
|
|
if (!flush) {
|
|
if (btree_node_dirty(b))
|
|
goto out_unlock;
|
|
|
|
if (down_trylock(&b->io_mutex))
|
|
goto out_unlock;
|
|
up(&b->io_mutex);
|
|
}
|
|
|
|
retry:
|
|
/*
|
|
* BTREE_NODE_dirty might be cleared in btree_flush_btree() by
|
|
* __bch_btree_node_write(). To avoid an extra flush, acquire
|
|
* b->write_lock before checking BTREE_NODE_dirty bit.
|
|
*/
|
|
mutex_lock(&b->write_lock);
|
|
/*
|
|
* If this btree node is selected in btree_flush_write() by journal
|
|
* code, delay and retry until the node is flushed by journal code
|
|
* and BTREE_NODE_journal_flush bit cleared by btree_flush_write().
|
|
*/
|
|
if (btree_node_journal_flush(b)) {
|
|
pr_debug("bnode %p is flushing by journal, retry\n", b);
|
|
mutex_unlock(&b->write_lock);
|
|
udelay(1);
|
|
goto retry;
|
|
}
|
|
|
|
if (btree_node_dirty(b))
|
|
__bch_btree_node_write(b, &cl);
|
|
mutex_unlock(&b->write_lock);
|
|
|
|
closure_sync(&cl);
|
|
|
|
/* wait for any in flight btree write */
|
|
down(&b->io_mutex);
|
|
up(&b->io_mutex);
|
|
|
|
return 0;
|
|
out_unlock:
|
|
rw_unlock(true, b);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static unsigned long bch_mca_scan(struct shrinker *shrink,
|
|
struct shrink_control *sc)
|
|
{
|
|
struct cache_set *c = container_of(shrink, struct cache_set, shrink);
|
|
struct btree *b, *t;
|
|
unsigned long i, nr = sc->nr_to_scan;
|
|
unsigned long freed = 0;
|
|
unsigned int btree_cache_used;
|
|
|
|
if (c->shrinker_disabled)
|
|
return SHRINK_STOP;
|
|
|
|
if (c->btree_cache_alloc_lock)
|
|
return SHRINK_STOP;
|
|
|
|
/* Return -1 if we can't do anything right now */
|
|
if (sc->gfp_mask & __GFP_IO)
|
|
mutex_lock(&c->bucket_lock);
|
|
else if (!mutex_trylock(&c->bucket_lock))
|
|
return -1;
|
|
|
|
/*
|
|
* It's _really_ critical that we don't free too many btree nodes - we
|
|
* have to always leave ourselves a reserve. The reserve is how we
|
|
* guarantee that allocating memory for a new btree node can always
|
|
* succeed, so that inserting keys into the btree can always succeed and
|
|
* IO can always make forward progress:
|
|
*/
|
|
nr /= c->btree_pages;
|
|
if (nr == 0)
|
|
nr = 1;
|
|
nr = min_t(unsigned long, nr, mca_can_free(c));
|
|
|
|
i = 0;
|
|
btree_cache_used = c->btree_cache_used;
|
|
list_for_each_entry_safe_reverse(b, t, &c->btree_cache_freeable, list) {
|
|
if (nr <= 0)
|
|
goto out;
|
|
|
|
if (!mca_reap(b, 0, false)) {
|
|
mca_data_free(b);
|
|
rw_unlock(true, b);
|
|
freed++;
|
|
}
|
|
nr--;
|
|
i++;
|
|
}
|
|
|
|
list_for_each_entry_safe_reverse(b, t, &c->btree_cache, list) {
|
|
if (nr <= 0 || i >= btree_cache_used)
|
|
goto out;
|
|
|
|
if (!mca_reap(b, 0, false)) {
|
|
mca_bucket_free(b);
|
|
mca_data_free(b);
|
|
rw_unlock(true, b);
|
|
freed++;
|
|
}
|
|
|
|
nr--;
|
|
i++;
|
|
}
|
|
out:
|
|
mutex_unlock(&c->bucket_lock);
|
|
return freed * c->btree_pages;
|
|
}
|
|
|
|
static unsigned long bch_mca_count(struct shrinker *shrink,
|
|
struct shrink_control *sc)
|
|
{
|
|
struct cache_set *c = container_of(shrink, struct cache_set, shrink);
|
|
|
|
if (c->shrinker_disabled)
|
|
return 0;
|
|
|
|
if (c->btree_cache_alloc_lock)
|
|
return 0;
|
|
|
|
return mca_can_free(c) * c->btree_pages;
|
|
}
|
|
|
|
void bch_btree_cache_free(struct cache_set *c)
|
|
{
|
|
struct btree *b;
|
|
struct closure cl;
|
|
|
|
closure_init_stack(&cl);
|
|
|
|
if (c->shrink.list.next)
|
|
unregister_shrinker(&c->shrink);
|
|
|
|
mutex_lock(&c->bucket_lock);
|
|
|
|
#ifdef CONFIG_BCACHE_DEBUG
|
|
if (c->verify_data)
|
|
list_move(&c->verify_data->list, &c->btree_cache);
|
|
|
|
free_pages((unsigned long) c->verify_ondisk, ilog2(meta_bucket_pages(&c->cache->sb)));
|
|
#endif
|
|
|
|
list_splice(&c->btree_cache_freeable,
|
|
&c->btree_cache);
|
|
|
|
while (!list_empty(&c->btree_cache)) {
|
|
b = list_first_entry(&c->btree_cache, struct btree, list);
|
|
|
|
/*
|
|
* This function is called by cache_set_free(), no I/O
|
|
* request on cache now, it is unnecessary to acquire
|
|
* b->write_lock before clearing BTREE_NODE_dirty anymore.
|
|
*/
|
|
if (btree_node_dirty(b)) {
|
|
btree_complete_write(b, btree_current_write(b));
|
|
clear_bit(BTREE_NODE_dirty, &b->flags);
|
|
}
|
|
mca_data_free(b);
|
|
}
|
|
|
|
while (!list_empty(&c->btree_cache_freed)) {
|
|
b = list_first_entry(&c->btree_cache_freed,
|
|
struct btree, list);
|
|
list_del(&b->list);
|
|
cancel_delayed_work_sync(&b->work);
|
|
kfree(b);
|
|
}
|
|
|
|
mutex_unlock(&c->bucket_lock);
|
|
}
|
|
|
|
int bch_btree_cache_alloc(struct cache_set *c)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < mca_reserve(c); i++)
|
|
if (!mca_bucket_alloc(c, &ZERO_KEY, GFP_KERNEL))
|
|
return -ENOMEM;
|
|
|
|
list_splice_init(&c->btree_cache,
|
|
&c->btree_cache_freeable);
|
|
|
|
#ifdef CONFIG_BCACHE_DEBUG
|
|
mutex_init(&c->verify_lock);
|
|
|
|
c->verify_ondisk = (void *)
|
|
__get_free_pages(GFP_KERNEL|__GFP_COMP,
|
|
ilog2(meta_bucket_pages(&c->cache->sb)));
|
|
if (!c->verify_ondisk) {
|
|
/*
|
|
* Don't worry about the mca_rereserve buckets
|
|
* allocated in previous for-loop, they will be
|
|
* handled properly in bch_cache_set_unregister().
|
|
*/
|
|
return -ENOMEM;
|
|
}
|
|
|
|
c->verify_data = mca_bucket_alloc(c, &ZERO_KEY, GFP_KERNEL);
|
|
|
|
if (c->verify_data &&
|
|
c->verify_data->keys.set->data)
|
|
list_del_init(&c->verify_data->list);
|
|
else
|
|
c->verify_data = NULL;
|
|
#endif
|
|
|
|
c->shrink.count_objects = bch_mca_count;
|
|
c->shrink.scan_objects = bch_mca_scan;
|
|
c->shrink.seeks = 4;
|
|
c->shrink.batch = c->btree_pages * 2;
|
|
|
|
if (register_shrinker(&c->shrink))
|
|
pr_warn("bcache: %s: could not register shrinker\n",
|
|
__func__);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Btree in memory cache - hash table */
|
|
|
|
static struct hlist_head *mca_hash(struct cache_set *c, struct bkey *k)
|
|
{
|
|
return &c->bucket_hash[hash_32(PTR_HASH(c, k), BUCKET_HASH_BITS)];
|
|
}
|
|
|
|
static struct btree *mca_find(struct cache_set *c, struct bkey *k)
|
|
{
|
|
struct btree *b;
|
|
|
|
rcu_read_lock();
|
|
hlist_for_each_entry_rcu(b, mca_hash(c, k), hash)
|
|
if (PTR_HASH(c, &b->key) == PTR_HASH(c, k))
|
|
goto out;
|
|
b = NULL;
|
|
out:
|
|
rcu_read_unlock();
|
|
return b;
|
|
}
|
|
|
|
static int mca_cannibalize_lock(struct cache_set *c, struct btree_op *op)
|
|
{
|
|
spin_lock(&c->btree_cannibalize_lock);
|
|
if (likely(c->btree_cache_alloc_lock == NULL)) {
|
|
c->btree_cache_alloc_lock = current;
|
|
} else if (c->btree_cache_alloc_lock != current) {
|
|
if (op)
|
|
prepare_to_wait(&c->btree_cache_wait, &op->wait,
|
|
TASK_UNINTERRUPTIBLE);
|
|
spin_unlock(&c->btree_cannibalize_lock);
|
|
return -EINTR;
|
|
}
|
|
spin_unlock(&c->btree_cannibalize_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct btree *mca_cannibalize(struct cache_set *c, struct btree_op *op,
|
|
struct bkey *k)
|
|
{
|
|
struct btree *b;
|
|
|
|
trace_bcache_btree_cache_cannibalize(c);
|
|
|
|
if (mca_cannibalize_lock(c, op))
|
|
return ERR_PTR(-EINTR);
|
|
|
|
list_for_each_entry_reverse(b, &c->btree_cache, list)
|
|
if (!mca_reap(b, btree_order(k), false))
|
|
return b;
|
|
|
|
list_for_each_entry_reverse(b, &c->btree_cache, list)
|
|
if (!mca_reap(b, btree_order(k), true))
|
|
return b;
|
|
|
|
WARN(1, "btree cache cannibalize failed\n");
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
/*
|
|
* We can only have one thread cannibalizing other cached btree nodes at a time,
|
|
* or we'll deadlock. We use an open coded mutex to ensure that, which a
|
|
* cannibalize_bucket() will take. This means every time we unlock the root of
|
|
* the btree, we need to release this lock if we have it held.
|
|
*/
|
|
static void bch_cannibalize_unlock(struct cache_set *c)
|
|
{
|
|
spin_lock(&c->btree_cannibalize_lock);
|
|
if (c->btree_cache_alloc_lock == current) {
|
|
c->btree_cache_alloc_lock = NULL;
|
|
wake_up(&c->btree_cache_wait);
|
|
}
|
|
spin_unlock(&c->btree_cannibalize_lock);
|
|
}
|
|
|
|
static struct btree *mca_alloc(struct cache_set *c, struct btree_op *op,
|
|
struct bkey *k, int level)
|
|
{
|
|
struct btree *b;
|
|
|
|
BUG_ON(current->bio_list);
|
|
|
|
lockdep_assert_held(&c->bucket_lock);
|
|
|
|
if (mca_find(c, k))
|
|
return NULL;
|
|
|
|
/* btree_free() doesn't free memory; it sticks the node on the end of
|
|
* the list. Check if there's any freed nodes there:
|
|
*/
|
|
list_for_each_entry(b, &c->btree_cache_freeable, list)
|
|
if (!mca_reap(b, btree_order(k), false))
|
|
goto out;
|
|
|
|
/* We never free struct btree itself, just the memory that holds the on
|
|
* disk node. Check the freed list before allocating a new one:
|
|
*/
|
|
list_for_each_entry(b, &c->btree_cache_freed, list)
|
|
if (!mca_reap(b, 0, false)) {
|
|
mca_data_alloc(b, k, __GFP_NOWARN|GFP_NOIO);
|
|
if (!b->keys.set[0].data)
|
|
goto err;
|
|
else
|
|
goto out;
|
|
}
|
|
|
|
b = mca_bucket_alloc(c, k, __GFP_NOWARN|GFP_NOIO);
|
|
if (!b)
|
|
goto err;
|
|
|
|
BUG_ON(!down_write_trylock(&b->lock));
|
|
if (!b->keys.set->data)
|
|
goto err;
|
|
out:
|
|
BUG_ON(b->io_mutex.count != 1);
|
|
|
|
bkey_copy(&b->key, k);
|
|
list_move(&b->list, &c->btree_cache);
|
|
hlist_del_init_rcu(&b->hash);
|
|
hlist_add_head_rcu(&b->hash, mca_hash(c, k));
|
|
|
|
lock_set_subclass(&b->lock.dep_map, level + 1, _THIS_IP_);
|
|
b->parent = (void *) ~0UL;
|
|
b->flags = 0;
|
|
b->written = 0;
|
|
b->level = level;
|
|
|
|
if (!b->level)
|
|
bch_btree_keys_init(&b->keys, &bch_extent_keys_ops,
|
|
&b->c->expensive_debug_checks);
|
|
else
|
|
bch_btree_keys_init(&b->keys, &bch_btree_keys_ops,
|
|
&b->c->expensive_debug_checks);
|
|
|
|
return b;
|
|
err:
|
|
if (b)
|
|
rw_unlock(true, b);
|
|
|
|
b = mca_cannibalize(c, op, k);
|
|
if (!IS_ERR(b))
|
|
goto out;
|
|
|
|
return b;
|
|
}
|
|
|
|
/*
|
|
* bch_btree_node_get - find a btree node in the cache and lock it, reading it
|
|
* in from disk if necessary.
|
|
*
|
|
* If IO is necessary and running under submit_bio_noacct, returns -EAGAIN.
|
|
*
|
|
* The btree node will have either a read or a write lock held, depending on
|
|
* level and op->lock.
|
|
*/
|
|
struct btree *bch_btree_node_get(struct cache_set *c, struct btree_op *op,
|
|
struct bkey *k, int level, bool write,
|
|
struct btree *parent)
|
|
{
|
|
int i = 0;
|
|
struct btree *b;
|
|
|
|
BUG_ON(level < 0);
|
|
retry:
|
|
b = mca_find(c, k);
|
|
|
|
if (!b) {
|
|
if (current->bio_list)
|
|
return ERR_PTR(-EAGAIN);
|
|
|
|
mutex_lock(&c->bucket_lock);
|
|
b = mca_alloc(c, op, k, level);
|
|
mutex_unlock(&c->bucket_lock);
|
|
|
|
if (!b)
|
|
goto retry;
|
|
if (IS_ERR(b))
|
|
return b;
|
|
|
|
bch_btree_node_read(b);
|
|
|
|
if (!write)
|
|
downgrade_write(&b->lock);
|
|
} else {
|
|
rw_lock(write, b, level);
|
|
if (PTR_HASH(c, &b->key) != PTR_HASH(c, k)) {
|
|
rw_unlock(write, b);
|
|
goto retry;
|
|
}
|
|
BUG_ON(b->level != level);
|
|
}
|
|
|
|
if (btree_node_io_error(b)) {
|
|
rw_unlock(write, b);
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
|
|
BUG_ON(!b->written);
|
|
|
|
b->parent = parent;
|
|
|
|
for (; i <= b->keys.nsets && b->keys.set[i].size; i++) {
|
|
prefetch(b->keys.set[i].tree);
|
|
prefetch(b->keys.set[i].data);
|
|
}
|
|
|
|
for (; i <= b->keys.nsets; i++)
|
|
prefetch(b->keys.set[i].data);
|
|
|
|
return b;
|
|
}
|
|
|
|
static void btree_node_prefetch(struct btree *parent, struct bkey *k)
|
|
{
|
|
struct btree *b;
|
|
|
|
mutex_lock(&parent->c->bucket_lock);
|
|
b = mca_alloc(parent->c, NULL, k, parent->level - 1);
|
|
mutex_unlock(&parent->c->bucket_lock);
|
|
|
|
if (!IS_ERR_OR_NULL(b)) {
|
|
b->parent = parent;
|
|
bch_btree_node_read(b);
|
|
rw_unlock(true, b);
|
|
}
|
|
}
|
|
|
|
/* Btree alloc */
|
|
|
|
static void btree_node_free(struct btree *b)
|
|
{
|
|
trace_bcache_btree_node_free(b);
|
|
|
|
BUG_ON(b == b->c->root);
|
|
|
|
retry:
|
|
mutex_lock(&b->write_lock);
|
|
/*
|
|
* If the btree node is selected and flushing in btree_flush_write(),
|
|
* delay and retry until the BTREE_NODE_journal_flush bit cleared,
|
|
* then it is safe to free the btree node here. Otherwise this btree
|
|
* node will be in race condition.
|
|
*/
|
|
if (btree_node_journal_flush(b)) {
|
|
mutex_unlock(&b->write_lock);
|
|
pr_debug("bnode %p journal_flush set, retry\n", b);
|
|
udelay(1);
|
|
goto retry;
|
|
}
|
|
|
|
if (btree_node_dirty(b)) {
|
|
btree_complete_write(b, btree_current_write(b));
|
|
clear_bit(BTREE_NODE_dirty, &b->flags);
|
|
}
|
|
|
|
mutex_unlock(&b->write_lock);
|
|
|
|
cancel_delayed_work(&b->work);
|
|
|
|
mutex_lock(&b->c->bucket_lock);
|
|
bch_bucket_free(b->c, &b->key);
|
|
mca_bucket_free(b);
|
|
mutex_unlock(&b->c->bucket_lock);
|
|
}
|
|
|
|
struct btree *__bch_btree_node_alloc(struct cache_set *c, struct btree_op *op,
|
|
int level, bool wait,
|
|
struct btree *parent)
|
|
{
|
|
BKEY_PADDED(key) k;
|
|
struct btree *b = ERR_PTR(-EAGAIN);
|
|
|
|
mutex_lock(&c->bucket_lock);
|
|
retry:
|
|
if (__bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, wait))
|
|
goto err;
|
|
|
|
bkey_put(c, &k.key);
|
|
SET_KEY_SIZE(&k.key, c->btree_pages * PAGE_SECTORS);
|
|
|
|
b = mca_alloc(c, op, &k.key, level);
|
|
if (IS_ERR(b))
|
|
goto err_free;
|
|
|
|
if (!b) {
|
|
cache_bug(c,
|
|
"Tried to allocate bucket that was in btree cache");
|
|
goto retry;
|
|
}
|
|
|
|
b->parent = parent;
|
|
bch_bset_init_next(&b->keys, b->keys.set->data, bset_magic(&b->c->cache->sb));
|
|
|
|
mutex_unlock(&c->bucket_lock);
|
|
|
|
trace_bcache_btree_node_alloc(b);
|
|
return b;
|
|
err_free:
|
|
bch_bucket_free(c, &k.key);
|
|
err:
|
|
mutex_unlock(&c->bucket_lock);
|
|
|
|
trace_bcache_btree_node_alloc_fail(c);
|
|
return b;
|
|
}
|
|
|
|
static struct btree *bch_btree_node_alloc(struct cache_set *c,
|
|
struct btree_op *op, int level,
|
|
struct btree *parent)
|
|
{
|
|
return __bch_btree_node_alloc(c, op, level, op != NULL, parent);
|
|
}
|
|
|
|
static struct btree *btree_node_alloc_replacement(struct btree *b,
|
|
struct btree_op *op)
|
|
{
|
|
struct btree *n = bch_btree_node_alloc(b->c, op, b->level, b->parent);
|
|
|
|
if (!IS_ERR_OR_NULL(n)) {
|
|
mutex_lock(&n->write_lock);
|
|
bch_btree_sort_into(&b->keys, &n->keys, &b->c->sort);
|
|
bkey_copy_key(&n->key, &b->key);
|
|
mutex_unlock(&n->write_lock);
|
|
}
|
|
|
|
return n;
|
|
}
|
|
|
|
static void make_btree_freeing_key(struct btree *b, struct bkey *k)
|
|
{
|
|
unsigned int i;
|
|
|
|
mutex_lock(&b->c->bucket_lock);
|
|
|
|
atomic_inc(&b->c->prio_blocked);
|
|
|
|
bkey_copy(k, &b->key);
|
|
bkey_copy_key(k, &ZERO_KEY);
|
|
|
|
for (i = 0; i < KEY_PTRS(k); i++)
|
|
SET_PTR_GEN(k, i,
|
|
bch_inc_gen(b->c->cache,
|
|
PTR_BUCKET(b->c, &b->key, i)));
|
|
|
|
mutex_unlock(&b->c->bucket_lock);
|
|
}
|
|
|
|
static int btree_check_reserve(struct btree *b, struct btree_op *op)
|
|
{
|
|
struct cache_set *c = b->c;
|
|
struct cache *ca = c->cache;
|
|
unsigned int reserve = (c->root->level - b->level) * 2 + 1;
|
|
|
|
mutex_lock(&c->bucket_lock);
|
|
|
|
if (fifo_used(&ca->free[RESERVE_BTREE]) < reserve) {
|
|
if (op)
|
|
prepare_to_wait(&c->btree_cache_wait, &op->wait,
|
|
TASK_UNINTERRUPTIBLE);
|
|
mutex_unlock(&c->bucket_lock);
|
|
return -EINTR;
|
|
}
|
|
|
|
mutex_unlock(&c->bucket_lock);
|
|
|
|
return mca_cannibalize_lock(b->c, op);
|
|
}
|
|
|
|
/* Garbage collection */
|
|
|
|
static uint8_t __bch_btree_mark_key(struct cache_set *c, int level,
|
|
struct bkey *k)
|
|
{
|
|
uint8_t stale = 0;
|
|
unsigned int i;
|
|
struct bucket *g;
|
|
|
|
/*
|
|
* ptr_invalid() can't return true for the keys that mark btree nodes as
|
|
* freed, but since ptr_bad() returns true we'll never actually use them
|
|
* for anything and thus we don't want mark their pointers here
|
|
*/
|
|
if (!bkey_cmp(k, &ZERO_KEY))
|
|
return stale;
|
|
|
|
for (i = 0; i < KEY_PTRS(k); i++) {
|
|
if (!ptr_available(c, k, i))
|
|
continue;
|
|
|
|
g = PTR_BUCKET(c, k, i);
|
|
|
|
if (gen_after(g->last_gc, PTR_GEN(k, i)))
|
|
g->last_gc = PTR_GEN(k, i);
|
|
|
|
if (ptr_stale(c, k, i)) {
|
|
stale = max(stale, ptr_stale(c, k, i));
|
|
continue;
|
|
}
|
|
|
|
cache_bug_on(GC_MARK(g) &&
|
|
(GC_MARK(g) == GC_MARK_METADATA) != (level != 0),
|
|
c, "inconsistent ptrs: mark = %llu, level = %i",
|
|
GC_MARK(g), level);
|
|
|
|
if (level)
|
|
SET_GC_MARK(g, GC_MARK_METADATA);
|
|
else if (KEY_DIRTY(k))
|
|
SET_GC_MARK(g, GC_MARK_DIRTY);
|
|
else if (!GC_MARK(g))
|
|
SET_GC_MARK(g, GC_MARK_RECLAIMABLE);
|
|
|
|
/* guard against overflow */
|
|
SET_GC_SECTORS_USED(g, min_t(unsigned int,
|
|
GC_SECTORS_USED(g) + KEY_SIZE(k),
|
|
MAX_GC_SECTORS_USED));
|
|
|
|
BUG_ON(!GC_SECTORS_USED(g));
|
|
}
|
|
|
|
return stale;
|
|
}
|
|
|
|
#define btree_mark_key(b, k) __bch_btree_mark_key(b->c, b->level, k)
|
|
|
|
void bch_initial_mark_key(struct cache_set *c, int level, struct bkey *k)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < KEY_PTRS(k); i++)
|
|
if (ptr_available(c, k, i) &&
|
|
!ptr_stale(c, k, i)) {
|
|
struct bucket *b = PTR_BUCKET(c, k, i);
|
|
|
|
b->gen = PTR_GEN(k, i);
|
|
|
|
if (level && bkey_cmp(k, &ZERO_KEY))
|
|
b->prio = BTREE_PRIO;
|
|
else if (!level && b->prio == BTREE_PRIO)
|
|
b->prio = INITIAL_PRIO;
|
|
}
|
|
|
|
__bch_btree_mark_key(c, level, k);
|
|
}
|
|
|
|
void bch_update_bucket_in_use(struct cache_set *c, struct gc_stat *stats)
|
|
{
|
|
stats->in_use = (c->nbuckets - c->avail_nbuckets) * 100 / c->nbuckets;
|
|
}
|
|
|
|
static bool btree_gc_mark_node(struct btree *b, struct gc_stat *gc)
|
|
{
|
|
uint8_t stale = 0;
|
|
unsigned int keys = 0, good_keys = 0;
|
|
struct bkey *k;
|
|
struct btree_iter iter;
|
|
struct bset_tree *t;
|
|
|
|
gc->nodes++;
|
|
|
|
for_each_key_filter(&b->keys, k, &iter, bch_ptr_invalid) {
|
|
stale = max(stale, btree_mark_key(b, k));
|
|
keys++;
|
|
|
|
if (bch_ptr_bad(&b->keys, k))
|
|
continue;
|
|
|
|
gc->key_bytes += bkey_u64s(k);
|
|
gc->nkeys++;
|
|
good_keys++;
|
|
|
|
gc->data += KEY_SIZE(k);
|
|
}
|
|
|
|
for (t = b->keys.set; t <= &b->keys.set[b->keys.nsets]; t++)
|
|
btree_bug_on(t->size &&
|
|
bset_written(&b->keys, t) &&
|
|
bkey_cmp(&b->key, &t->end) < 0,
|
|
b, "found short btree key in gc");
|
|
|
|
if (b->c->gc_always_rewrite)
|
|
return true;
|
|
|
|
if (stale > 10)
|
|
return true;
|
|
|
|
if ((keys - good_keys) * 2 > keys)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
#define GC_MERGE_NODES 4U
|
|
|
|
struct gc_merge_info {
|
|
struct btree *b;
|
|
unsigned int keys;
|
|
};
|
|
|
|
static int bch_btree_insert_node(struct btree *b, struct btree_op *op,
|
|
struct keylist *insert_keys,
|
|
atomic_t *journal_ref,
|
|
struct bkey *replace_key);
|
|
|
|
static int btree_gc_coalesce(struct btree *b, struct btree_op *op,
|
|
struct gc_stat *gc, struct gc_merge_info *r)
|
|
{
|
|
unsigned int i, nodes = 0, keys = 0, blocks;
|
|
struct btree *new_nodes[GC_MERGE_NODES];
|
|
struct keylist keylist;
|
|
struct closure cl;
|
|
struct bkey *k;
|
|
|
|
bch_keylist_init(&keylist);
|
|
|
|
if (btree_check_reserve(b, NULL))
|
|
return 0;
|
|
|
|
memset(new_nodes, 0, sizeof(new_nodes));
|
|
closure_init_stack(&cl);
|
|
|
|
while (nodes < GC_MERGE_NODES && !IS_ERR_OR_NULL(r[nodes].b))
|
|
keys += r[nodes++].keys;
|
|
|
|
blocks = btree_default_blocks(b->c) * 2 / 3;
|
|
|
|
if (nodes < 2 ||
|
|
__set_blocks(b->keys.set[0].data, keys,
|
|
block_bytes(b->c->cache)) > blocks * (nodes - 1))
|
|
return 0;
|
|
|
|
for (i = 0; i < nodes; i++) {
|
|
new_nodes[i] = btree_node_alloc_replacement(r[i].b, NULL);
|
|
if (IS_ERR_OR_NULL(new_nodes[i]))
|
|
goto out_nocoalesce;
|
|
}
|
|
|
|
/*
|
|
* We have to check the reserve here, after we've allocated our new
|
|
* nodes, to make sure the insert below will succeed - we also check
|
|
* before as an optimization to potentially avoid a bunch of expensive
|
|
* allocs/sorts
|
|
*/
|
|
if (btree_check_reserve(b, NULL))
|
|
goto out_nocoalesce;
|
|
|
|
for (i = 0; i < nodes; i++)
|
|
mutex_lock(&new_nodes[i]->write_lock);
|
|
|
|
for (i = nodes - 1; i > 0; --i) {
|
|
struct bset *n1 = btree_bset_first(new_nodes[i]);
|
|
struct bset *n2 = btree_bset_first(new_nodes[i - 1]);
|
|
struct bkey *k, *last = NULL;
|
|
|
|
keys = 0;
|
|
|
|
if (i > 1) {
|
|
for (k = n2->start;
|
|
k < bset_bkey_last(n2);
|
|
k = bkey_next(k)) {
|
|
if (__set_blocks(n1, n1->keys + keys +
|
|
bkey_u64s(k),
|
|
block_bytes(b->c->cache)) > blocks)
|
|
break;
|
|
|
|
last = k;
|
|
keys += bkey_u64s(k);
|
|
}
|
|
} else {
|
|
/*
|
|
* Last node we're not getting rid of - we're getting
|
|
* rid of the node at r[0]. Have to try and fit all of
|
|
* the remaining keys into this node; we can't ensure
|
|
* they will always fit due to rounding and variable
|
|
* length keys (shouldn't be possible in practice,
|
|
* though)
|
|
*/
|
|
if (__set_blocks(n1, n1->keys + n2->keys,
|
|
block_bytes(b->c->cache)) >
|
|
btree_blocks(new_nodes[i]))
|
|
goto out_unlock_nocoalesce;
|
|
|
|
keys = n2->keys;
|
|
/* Take the key of the node we're getting rid of */
|
|
last = &r->b->key;
|
|
}
|
|
|
|
BUG_ON(__set_blocks(n1, n1->keys + keys, block_bytes(b->c->cache)) >
|
|
btree_blocks(new_nodes[i]));
|
|
|
|
if (last)
|
|
bkey_copy_key(&new_nodes[i]->key, last);
|
|
|
|
memcpy(bset_bkey_last(n1),
|
|
n2->start,
|
|
(void *) bset_bkey_idx(n2, keys) - (void *) n2->start);
|
|
|
|
n1->keys += keys;
|
|
r[i].keys = n1->keys;
|
|
|
|
memmove(n2->start,
|
|
bset_bkey_idx(n2, keys),
|
|
(void *) bset_bkey_last(n2) -
|
|
(void *) bset_bkey_idx(n2, keys));
|
|
|
|
n2->keys -= keys;
|
|
|
|
if (__bch_keylist_realloc(&keylist,
|
|
bkey_u64s(&new_nodes[i]->key)))
|
|
goto out_unlock_nocoalesce;
|
|
|
|
bch_btree_node_write(new_nodes[i], &cl);
|
|
bch_keylist_add(&keylist, &new_nodes[i]->key);
|
|
}
|
|
|
|
for (i = 0; i < nodes; i++)
|
|
mutex_unlock(&new_nodes[i]->write_lock);
|
|
|
|
closure_sync(&cl);
|
|
|
|
/* We emptied out this node */
|
|
BUG_ON(btree_bset_first(new_nodes[0])->keys);
|
|
btree_node_free(new_nodes[0]);
|
|
rw_unlock(true, new_nodes[0]);
|
|
new_nodes[0] = NULL;
|
|
|
|
for (i = 0; i < nodes; i++) {
|
|
if (__bch_keylist_realloc(&keylist, bkey_u64s(&r[i].b->key)))
|
|
goto out_nocoalesce;
|
|
|
|
make_btree_freeing_key(r[i].b, keylist.top);
|
|
bch_keylist_push(&keylist);
|
|
}
|
|
|
|
bch_btree_insert_node(b, op, &keylist, NULL, NULL);
|
|
BUG_ON(!bch_keylist_empty(&keylist));
|
|
|
|
for (i = 0; i < nodes; i++) {
|
|
btree_node_free(r[i].b);
|
|
rw_unlock(true, r[i].b);
|
|
|
|
r[i].b = new_nodes[i];
|
|
}
|
|
|
|
memmove(r, r + 1, sizeof(r[0]) * (nodes - 1));
|
|
r[nodes - 1].b = ERR_PTR(-EINTR);
|
|
|
|
trace_bcache_btree_gc_coalesce(nodes);
|
|
gc->nodes--;
|
|
|
|
bch_keylist_free(&keylist);
|
|
|
|
/* Invalidated our iterator */
|
|
return -EINTR;
|
|
|
|
out_unlock_nocoalesce:
|
|
for (i = 0; i < nodes; i++)
|
|
mutex_unlock(&new_nodes[i]->write_lock);
|
|
|
|
out_nocoalesce:
|
|
closure_sync(&cl);
|
|
|
|
while ((k = bch_keylist_pop(&keylist)))
|
|
if (!bkey_cmp(k, &ZERO_KEY))
|
|
atomic_dec(&b->c->prio_blocked);
|
|
bch_keylist_free(&keylist);
|
|
|
|
for (i = 0; i < nodes; i++)
|
|
if (!IS_ERR_OR_NULL(new_nodes[i])) {
|
|
btree_node_free(new_nodes[i]);
|
|
rw_unlock(true, new_nodes[i]);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int btree_gc_rewrite_node(struct btree *b, struct btree_op *op,
|
|
struct btree *replace)
|
|
{
|
|
struct keylist keys;
|
|
struct btree *n;
|
|
|
|
if (btree_check_reserve(b, NULL))
|
|
return 0;
|
|
|
|
n = btree_node_alloc_replacement(replace, NULL);
|
|
|
|
/* recheck reserve after allocating replacement node */
|
|
if (btree_check_reserve(b, NULL)) {
|
|
btree_node_free(n);
|
|
rw_unlock(true, n);
|
|
return 0;
|
|
}
|
|
|
|
bch_btree_node_write_sync(n);
|
|
|
|
bch_keylist_init(&keys);
|
|
bch_keylist_add(&keys, &n->key);
|
|
|
|
make_btree_freeing_key(replace, keys.top);
|
|
bch_keylist_push(&keys);
|
|
|
|
bch_btree_insert_node(b, op, &keys, NULL, NULL);
|
|
BUG_ON(!bch_keylist_empty(&keys));
|
|
|
|
btree_node_free(replace);
|
|
rw_unlock(true, n);
|
|
|
|
/* Invalidated our iterator */
|
|
return -EINTR;
|
|
}
|
|
|
|
static unsigned int btree_gc_count_keys(struct btree *b)
|
|
{
|
|
struct bkey *k;
|
|
struct btree_iter iter;
|
|
unsigned int ret = 0;
|
|
|
|
for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
|
|
ret += bkey_u64s(k);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static size_t btree_gc_min_nodes(struct cache_set *c)
|
|
{
|
|
size_t min_nodes;
|
|
|
|
/*
|
|
* Since incremental GC would stop 100ms when front
|
|
* side I/O comes, so when there are many btree nodes,
|
|
* if GC only processes constant (100) nodes each time,
|
|
* GC would last a long time, and the front side I/Os
|
|
* would run out of the buckets (since no new bucket
|
|
* can be allocated during GC), and be blocked again.
|
|
* So GC should not process constant nodes, but varied
|
|
* nodes according to the number of btree nodes, which
|
|
* realized by dividing GC into constant(100) times,
|
|
* so when there are many btree nodes, GC can process
|
|
* more nodes each time, otherwise, GC will process less
|
|
* nodes each time (but no less than MIN_GC_NODES)
|
|
*/
|
|
min_nodes = c->gc_stats.nodes / MAX_GC_TIMES;
|
|
if (min_nodes < MIN_GC_NODES)
|
|
min_nodes = MIN_GC_NODES;
|
|
|
|
return min_nodes;
|
|
}
|
|
|
|
|
|
static int btree_gc_recurse(struct btree *b, struct btree_op *op,
|
|
struct closure *writes, struct gc_stat *gc)
|
|
{
|
|
int ret = 0;
|
|
bool should_rewrite;
|
|
struct bkey *k;
|
|
struct btree_iter iter;
|
|
struct gc_merge_info r[GC_MERGE_NODES];
|
|
struct gc_merge_info *i, *last = r + ARRAY_SIZE(r) - 1;
|
|
|
|
bch_btree_iter_init(&b->keys, &iter, &b->c->gc_done);
|
|
|
|
for (i = r; i < r + ARRAY_SIZE(r); i++)
|
|
i->b = ERR_PTR(-EINTR);
|
|
|
|
while (1) {
|
|
k = bch_btree_iter_next_filter(&iter, &b->keys, bch_ptr_bad);
|
|
if (k) {
|
|
r->b = bch_btree_node_get(b->c, op, k, b->level - 1,
|
|
true, b);
|
|
if (IS_ERR(r->b)) {
|
|
ret = PTR_ERR(r->b);
|
|
break;
|
|
}
|
|
|
|
r->keys = btree_gc_count_keys(r->b);
|
|
|
|
ret = btree_gc_coalesce(b, op, gc, r);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
if (!last->b)
|
|
break;
|
|
|
|
if (!IS_ERR(last->b)) {
|
|
should_rewrite = btree_gc_mark_node(last->b, gc);
|
|
if (should_rewrite) {
|
|
ret = btree_gc_rewrite_node(b, op, last->b);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
if (last->b->level) {
|
|
ret = btree_gc_recurse(last->b, op, writes, gc);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
bkey_copy_key(&b->c->gc_done, &last->b->key);
|
|
|
|
/*
|
|
* Must flush leaf nodes before gc ends, since replace
|
|
* operations aren't journalled
|
|
*/
|
|
mutex_lock(&last->b->write_lock);
|
|
if (btree_node_dirty(last->b))
|
|
bch_btree_node_write(last->b, writes);
|
|
mutex_unlock(&last->b->write_lock);
|
|
rw_unlock(true, last->b);
|
|
}
|
|
|
|
memmove(r + 1, r, sizeof(r[0]) * (GC_MERGE_NODES - 1));
|
|
r->b = NULL;
|
|
|
|
if (atomic_read(&b->c->search_inflight) &&
|
|
gc->nodes >= gc->nodes_pre + btree_gc_min_nodes(b->c)) {
|
|
gc->nodes_pre = gc->nodes;
|
|
ret = -EAGAIN;
|
|
break;
|
|
}
|
|
|
|
if (need_resched()) {
|
|
ret = -EAGAIN;
|
|
break;
|
|
}
|
|
}
|
|
|
|
for (i = r; i < r + ARRAY_SIZE(r); i++)
|
|
if (!IS_ERR_OR_NULL(i->b)) {
|
|
mutex_lock(&i->b->write_lock);
|
|
if (btree_node_dirty(i->b))
|
|
bch_btree_node_write(i->b, writes);
|
|
mutex_unlock(&i->b->write_lock);
|
|
rw_unlock(true, i->b);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int bch_btree_gc_root(struct btree *b, struct btree_op *op,
|
|
struct closure *writes, struct gc_stat *gc)
|
|
{
|
|
struct btree *n = NULL;
|
|
int ret = 0;
|
|
bool should_rewrite;
|
|
|
|
should_rewrite = btree_gc_mark_node(b, gc);
|
|
if (should_rewrite) {
|
|
n = btree_node_alloc_replacement(b, NULL);
|
|
|
|
if (!IS_ERR_OR_NULL(n)) {
|
|
bch_btree_node_write_sync(n);
|
|
|
|
bch_btree_set_root(n);
|
|
btree_node_free(b);
|
|
rw_unlock(true, n);
|
|
|
|
return -EINTR;
|
|
}
|
|
}
|
|
|
|
__bch_btree_mark_key(b->c, b->level + 1, &b->key);
|
|
|
|
if (b->level) {
|
|
ret = btree_gc_recurse(b, op, writes, gc);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
bkey_copy_key(&b->c->gc_done, &b->key);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void btree_gc_start(struct cache_set *c)
|
|
{
|
|
struct cache *ca;
|
|
struct bucket *b;
|
|
|
|
if (!c->gc_mark_valid)
|
|
return;
|
|
|
|
mutex_lock(&c->bucket_lock);
|
|
|
|
c->gc_mark_valid = 0;
|
|
c->gc_done = ZERO_KEY;
|
|
|
|
ca = c->cache;
|
|
for_each_bucket(b, ca) {
|
|
b->last_gc = b->gen;
|
|
if (!atomic_read(&b->pin)) {
|
|
SET_GC_MARK(b, 0);
|
|
SET_GC_SECTORS_USED(b, 0);
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&c->bucket_lock);
|
|
}
|
|
|
|
static void bch_btree_gc_finish(struct cache_set *c)
|
|
{
|
|
struct bucket *b;
|
|
struct cache *ca;
|
|
unsigned int i, j;
|
|
uint64_t *k;
|
|
|
|
mutex_lock(&c->bucket_lock);
|
|
|
|
set_gc_sectors(c);
|
|
c->gc_mark_valid = 1;
|
|
c->need_gc = 0;
|
|
|
|
for (i = 0; i < KEY_PTRS(&c->uuid_bucket); i++)
|
|
SET_GC_MARK(PTR_BUCKET(c, &c->uuid_bucket, i),
|
|
GC_MARK_METADATA);
|
|
|
|
/* don't reclaim buckets to which writeback keys point */
|
|
rcu_read_lock();
|
|
for (i = 0; i < c->devices_max_used; i++) {
|
|
struct bcache_device *d = c->devices[i];
|
|
struct cached_dev *dc;
|
|
struct keybuf_key *w, *n;
|
|
|
|
if (!d || UUID_FLASH_ONLY(&c->uuids[i]))
|
|
continue;
|
|
dc = container_of(d, struct cached_dev, disk);
|
|
|
|
spin_lock(&dc->writeback_keys.lock);
|
|
rbtree_postorder_for_each_entry_safe(w, n,
|
|
&dc->writeback_keys.keys, node)
|
|
for (j = 0; j < KEY_PTRS(&w->key); j++)
|
|
SET_GC_MARK(PTR_BUCKET(c, &w->key, j),
|
|
GC_MARK_DIRTY);
|
|
spin_unlock(&dc->writeback_keys.lock);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
c->avail_nbuckets = 0;
|
|
|
|
ca = c->cache;
|
|
ca->invalidate_needs_gc = 0;
|
|
|
|
for (k = ca->sb.d; k < ca->sb.d + ca->sb.keys; k++)
|
|
SET_GC_MARK(ca->buckets + *k, GC_MARK_METADATA);
|
|
|
|
for (k = ca->prio_buckets;
|
|
k < ca->prio_buckets + prio_buckets(ca) * 2; k++)
|
|
SET_GC_MARK(ca->buckets + *k, GC_MARK_METADATA);
|
|
|
|
for_each_bucket(b, ca) {
|
|
c->need_gc = max(c->need_gc, bucket_gc_gen(b));
|
|
|
|
if (atomic_read(&b->pin))
|
|
continue;
|
|
|
|
BUG_ON(!GC_MARK(b) && GC_SECTORS_USED(b));
|
|
|
|
if (!GC_MARK(b) || GC_MARK(b) == GC_MARK_RECLAIMABLE)
|
|
c->avail_nbuckets++;
|
|
}
|
|
|
|
mutex_unlock(&c->bucket_lock);
|
|
}
|
|
|
|
static void bch_btree_gc(struct cache_set *c)
|
|
{
|
|
int ret;
|
|
struct gc_stat stats;
|
|
struct closure writes;
|
|
struct btree_op op;
|
|
uint64_t start_time = local_clock();
|
|
|
|
trace_bcache_gc_start(c);
|
|
|
|
memset(&stats, 0, sizeof(struct gc_stat));
|
|
closure_init_stack(&writes);
|
|
bch_btree_op_init(&op, SHRT_MAX);
|
|
|
|
btree_gc_start(c);
|
|
|
|
/* if CACHE_SET_IO_DISABLE set, gc thread should stop too */
|
|
do {
|
|
ret = bcache_btree_root(gc_root, c, &op, &writes, &stats);
|
|
closure_sync(&writes);
|
|
cond_resched();
|
|
|
|
if (ret == -EAGAIN)
|
|
schedule_timeout_interruptible(msecs_to_jiffies
|
|
(GC_SLEEP_MS));
|
|
else if (ret)
|
|
pr_warn("gc failed!\n");
|
|
} while (ret && !test_bit(CACHE_SET_IO_DISABLE, &c->flags));
|
|
|
|
bch_btree_gc_finish(c);
|
|
wake_up_allocators(c);
|
|
|
|
bch_time_stats_update(&c->btree_gc_time, start_time);
|
|
|
|
stats.key_bytes *= sizeof(uint64_t);
|
|
stats.data <<= 9;
|
|
bch_update_bucket_in_use(c, &stats);
|
|
memcpy(&c->gc_stats, &stats, sizeof(struct gc_stat));
|
|
|
|
trace_bcache_gc_end(c);
|
|
|
|
bch_moving_gc(c);
|
|
}
|
|
|
|
static bool gc_should_run(struct cache_set *c)
|
|
{
|
|
struct cache *ca = c->cache;
|
|
|
|
if (ca->invalidate_needs_gc)
|
|
return true;
|
|
|
|
if (atomic_read(&c->sectors_to_gc) < 0)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static int bch_gc_thread(void *arg)
|
|
{
|
|
struct cache_set *c = arg;
|
|
|
|
while (1) {
|
|
wait_event_interruptible(c->gc_wait,
|
|
kthread_should_stop() ||
|
|
test_bit(CACHE_SET_IO_DISABLE, &c->flags) ||
|
|
gc_should_run(c));
|
|
|
|
if (kthread_should_stop() ||
|
|
test_bit(CACHE_SET_IO_DISABLE, &c->flags))
|
|
break;
|
|
|
|
set_gc_sectors(c);
|
|
bch_btree_gc(c);
|
|
}
|
|
|
|
wait_for_kthread_stop();
|
|
return 0;
|
|
}
|
|
|
|
int bch_gc_thread_start(struct cache_set *c)
|
|
{
|
|
c->gc_thread = kthread_run(bch_gc_thread, c, "bcache_gc");
|
|
return PTR_ERR_OR_ZERO(c->gc_thread);
|
|
}
|
|
|
|
/* Initial partial gc */
|
|
|
|
static int bch_btree_check_recurse(struct btree *b, struct btree_op *op)
|
|
{
|
|
int ret = 0;
|
|
struct bkey *k, *p = NULL;
|
|
struct btree_iter iter;
|
|
|
|
for_each_key_filter(&b->keys, k, &iter, bch_ptr_invalid)
|
|
bch_initial_mark_key(b->c, b->level, k);
|
|
|
|
bch_initial_mark_key(b->c, b->level + 1, &b->key);
|
|
|
|
if (b->level) {
|
|
bch_btree_iter_init(&b->keys, &iter, NULL);
|
|
|
|
do {
|
|
k = bch_btree_iter_next_filter(&iter, &b->keys,
|
|
bch_ptr_bad);
|
|
if (k) {
|
|
btree_node_prefetch(b, k);
|
|
/*
|
|
* initiallize c->gc_stats.nodes
|
|
* for incremental GC
|
|
*/
|
|
b->c->gc_stats.nodes++;
|
|
}
|
|
|
|
if (p)
|
|
ret = bcache_btree(check_recurse, p, b, op);
|
|
|
|
p = k;
|
|
} while (p && !ret);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
static int bch_btree_check_thread(void *arg)
|
|
{
|
|
int ret;
|
|
struct btree_check_info *info = arg;
|
|
struct btree_check_state *check_state = info->state;
|
|
struct cache_set *c = check_state->c;
|
|
struct btree_iter iter;
|
|
struct bkey *k, *p;
|
|
int cur_idx, prev_idx, skip_nr;
|
|
|
|
k = p = NULL;
|
|
cur_idx = prev_idx = 0;
|
|
ret = 0;
|
|
|
|
/* root node keys are checked before thread created */
|
|
bch_btree_iter_init(&c->root->keys, &iter, NULL);
|
|
k = bch_btree_iter_next_filter(&iter, &c->root->keys, bch_ptr_bad);
|
|
BUG_ON(!k);
|
|
|
|
p = k;
|
|
while (k) {
|
|
/*
|
|
* Fetch a root node key index, skip the keys which
|
|
* should be fetched by other threads, then check the
|
|
* sub-tree indexed by the fetched key.
|
|
*/
|
|
spin_lock(&check_state->idx_lock);
|
|
cur_idx = check_state->key_idx;
|
|
check_state->key_idx++;
|
|
spin_unlock(&check_state->idx_lock);
|
|
|
|
skip_nr = cur_idx - prev_idx;
|
|
|
|
while (skip_nr) {
|
|
k = bch_btree_iter_next_filter(&iter,
|
|
&c->root->keys,
|
|
bch_ptr_bad);
|
|
if (k)
|
|
p = k;
|
|
else {
|
|
/*
|
|
* No more keys to check in root node,
|
|
* current checking threads are enough,
|
|
* stop creating more.
|
|
*/
|
|
atomic_set(&check_state->enough, 1);
|
|
/* Update check_state->enough earlier */
|
|
smp_mb__after_atomic();
|
|
goto out;
|
|
}
|
|
skip_nr--;
|
|
cond_resched();
|
|
}
|
|
|
|
if (p) {
|
|
struct btree_op op;
|
|
|
|
btree_node_prefetch(c->root, p);
|
|
c->gc_stats.nodes++;
|
|
bch_btree_op_init(&op, 0);
|
|
ret = bcache_btree(check_recurse, p, c->root, &op);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
p = NULL;
|
|
prev_idx = cur_idx;
|
|
cond_resched();
|
|
}
|
|
|
|
out:
|
|
info->result = ret;
|
|
/* update check_state->started among all CPUs */
|
|
smp_mb__before_atomic();
|
|
if (atomic_dec_and_test(&check_state->started))
|
|
wake_up(&check_state->wait);
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
|
|
static int bch_btree_chkthread_nr(void)
|
|
{
|
|
int n = num_online_cpus()/2;
|
|
|
|
if (n == 0)
|
|
n = 1;
|
|
else if (n > BCH_BTR_CHKTHREAD_MAX)
|
|
n = BCH_BTR_CHKTHREAD_MAX;
|
|
|
|
return n;
|
|
}
|
|
|
|
int bch_btree_check(struct cache_set *c)
|
|
{
|
|
int ret = 0;
|
|
int i;
|
|
struct bkey *k = NULL;
|
|
struct btree_iter iter;
|
|
struct btree_check_state check_state;
|
|
|
|
/* check and mark root node keys */
|
|
for_each_key_filter(&c->root->keys, k, &iter, bch_ptr_invalid)
|
|
bch_initial_mark_key(c, c->root->level, k);
|
|
|
|
bch_initial_mark_key(c, c->root->level + 1, &c->root->key);
|
|
|
|
if (c->root->level == 0)
|
|
return 0;
|
|
|
|
memset(&check_state, 0, sizeof(struct btree_check_state));
|
|
check_state.c = c;
|
|
check_state.total_threads = bch_btree_chkthread_nr();
|
|
check_state.key_idx = 0;
|
|
spin_lock_init(&check_state.idx_lock);
|
|
atomic_set(&check_state.started, 0);
|
|
atomic_set(&check_state.enough, 0);
|
|
init_waitqueue_head(&check_state.wait);
|
|
|
|
rw_lock(0, c->root, c->root->level);
|
|
/*
|
|
* Run multiple threads to check btree nodes in parallel,
|
|
* if check_state.enough is non-zero, it means current
|
|
* running check threads are enough, unncessary to create
|
|
* more.
|
|
*/
|
|
for (i = 0; i < check_state.total_threads; i++) {
|
|
/* fetch latest check_state.enough earlier */
|
|
smp_mb__before_atomic();
|
|
if (atomic_read(&check_state.enough))
|
|
break;
|
|
|
|
check_state.infos[i].result = 0;
|
|
check_state.infos[i].state = &check_state;
|
|
|
|
check_state.infos[i].thread =
|
|
kthread_run(bch_btree_check_thread,
|
|
&check_state.infos[i],
|
|
"bch_btrchk[%d]", i);
|
|
if (IS_ERR(check_state.infos[i].thread)) {
|
|
pr_err("fails to run thread bch_btrchk[%d]\n", i);
|
|
for (--i; i >= 0; i--)
|
|
kthread_stop(check_state.infos[i].thread);
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
atomic_inc(&check_state.started);
|
|
}
|
|
|
|
/*
|
|
* Must wait for all threads to stop.
|
|
*/
|
|
wait_event(check_state.wait, atomic_read(&check_state.started) == 0);
|
|
|
|
for (i = 0; i < check_state.total_threads; i++) {
|
|
if (check_state.infos[i].result) {
|
|
ret = check_state.infos[i].result;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
rw_unlock(0, c->root);
|
|
return ret;
|
|
}
|
|
|
|
void bch_initial_gc_finish(struct cache_set *c)
|
|
{
|
|
struct cache *ca = c->cache;
|
|
struct bucket *b;
|
|
|
|
bch_btree_gc_finish(c);
|
|
|
|
mutex_lock(&c->bucket_lock);
|
|
|
|
/*
|
|
* We need to put some unused buckets directly on the prio freelist in
|
|
* order to get the allocator thread started - it needs freed buckets in
|
|
* order to rewrite the prios and gens, and it needs to rewrite prios
|
|
* and gens in order to free buckets.
|
|
*
|
|
* This is only safe for buckets that have no live data in them, which
|
|
* there should always be some of.
|
|
*/
|
|
for_each_bucket(b, ca) {
|
|
if (fifo_full(&ca->free[RESERVE_PRIO]) &&
|
|
fifo_full(&ca->free[RESERVE_BTREE]))
|
|
break;
|
|
|
|
if (bch_can_invalidate_bucket(ca, b) &&
|
|
!GC_MARK(b)) {
|
|
__bch_invalidate_one_bucket(ca, b);
|
|
if (!fifo_push(&ca->free[RESERVE_PRIO],
|
|
b - ca->buckets))
|
|
fifo_push(&ca->free[RESERVE_BTREE],
|
|
b - ca->buckets);
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&c->bucket_lock);
|
|
}
|
|
|
|
/* Btree insertion */
|
|
|
|
static bool btree_insert_key(struct btree *b, struct bkey *k,
|
|
struct bkey *replace_key)
|
|
{
|
|
unsigned int status;
|
|
|
|
BUG_ON(bkey_cmp(k, &b->key) > 0);
|
|
|
|
status = bch_btree_insert_key(&b->keys, k, replace_key);
|
|
if (status != BTREE_INSERT_STATUS_NO_INSERT) {
|
|
bch_check_keys(&b->keys, "%u for %s", status,
|
|
replace_key ? "replace" : "insert");
|
|
|
|
trace_bcache_btree_insert_key(b, k, replace_key != NULL,
|
|
status);
|
|
return true;
|
|
} else
|
|
return false;
|
|
}
|
|
|
|
static size_t insert_u64s_remaining(struct btree *b)
|
|
{
|
|
long ret = bch_btree_keys_u64s_remaining(&b->keys);
|
|
|
|
/*
|
|
* Might land in the middle of an existing extent and have to split it
|
|
*/
|
|
if (b->keys.ops->is_extents)
|
|
ret -= KEY_MAX_U64S;
|
|
|
|
return max(ret, 0L);
|
|
}
|
|
|
|
static bool bch_btree_insert_keys(struct btree *b, struct btree_op *op,
|
|
struct keylist *insert_keys,
|
|
struct bkey *replace_key)
|
|
{
|
|
bool ret = false;
|
|
int oldsize = bch_count_data(&b->keys);
|
|
|
|
while (!bch_keylist_empty(insert_keys)) {
|
|
struct bkey *k = insert_keys->keys;
|
|
|
|
if (bkey_u64s(k) > insert_u64s_remaining(b))
|
|
break;
|
|
|
|
if (bkey_cmp(k, &b->key) <= 0) {
|
|
if (!b->level)
|
|
bkey_put(b->c, k);
|
|
|
|
ret |= btree_insert_key(b, k, replace_key);
|
|
bch_keylist_pop_front(insert_keys);
|
|
} else if (bkey_cmp(&START_KEY(k), &b->key) < 0) {
|
|
BKEY_PADDED(key) temp;
|
|
bkey_copy(&temp.key, insert_keys->keys);
|
|
|
|
bch_cut_back(&b->key, &temp.key);
|
|
bch_cut_front(&b->key, insert_keys->keys);
|
|
|
|
ret |= btree_insert_key(b, &temp.key, replace_key);
|
|
break;
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!ret)
|
|
op->insert_collision = true;
|
|
|
|
BUG_ON(!bch_keylist_empty(insert_keys) && b->level);
|
|
|
|
BUG_ON(bch_count_data(&b->keys) < oldsize);
|
|
return ret;
|
|
}
|
|
|
|
static int btree_split(struct btree *b, struct btree_op *op,
|
|
struct keylist *insert_keys,
|
|
struct bkey *replace_key)
|
|
{
|
|
bool split;
|
|
struct btree *n1, *n2 = NULL, *n3 = NULL;
|
|
uint64_t start_time = local_clock();
|
|
struct closure cl;
|
|
struct keylist parent_keys;
|
|
|
|
closure_init_stack(&cl);
|
|
bch_keylist_init(&parent_keys);
|
|
|
|
if (btree_check_reserve(b, op)) {
|
|
if (!b->level)
|
|
return -EINTR;
|
|
else
|
|
WARN(1, "insufficient reserve for split\n");
|
|
}
|
|
|
|
n1 = btree_node_alloc_replacement(b, op);
|
|
if (IS_ERR(n1))
|
|
goto err;
|
|
|
|
split = set_blocks(btree_bset_first(n1),
|
|
block_bytes(n1->c->cache)) > (btree_blocks(b) * 4) / 5;
|
|
|
|
if (split) {
|
|
unsigned int keys = 0;
|
|
|
|
trace_bcache_btree_node_split(b, btree_bset_first(n1)->keys);
|
|
|
|
n2 = bch_btree_node_alloc(b->c, op, b->level, b->parent);
|
|
if (IS_ERR(n2))
|
|
goto err_free1;
|
|
|
|
if (!b->parent) {
|
|
n3 = bch_btree_node_alloc(b->c, op, b->level + 1, NULL);
|
|
if (IS_ERR(n3))
|
|
goto err_free2;
|
|
}
|
|
|
|
mutex_lock(&n1->write_lock);
|
|
mutex_lock(&n2->write_lock);
|
|
|
|
bch_btree_insert_keys(n1, op, insert_keys, replace_key);
|
|
|
|
/*
|
|
* Has to be a linear search because we don't have an auxiliary
|
|
* search tree yet
|
|
*/
|
|
|
|
while (keys < (btree_bset_first(n1)->keys * 3) / 5)
|
|
keys += bkey_u64s(bset_bkey_idx(btree_bset_first(n1),
|
|
keys));
|
|
|
|
bkey_copy_key(&n1->key,
|
|
bset_bkey_idx(btree_bset_first(n1), keys));
|
|
keys += bkey_u64s(bset_bkey_idx(btree_bset_first(n1), keys));
|
|
|
|
btree_bset_first(n2)->keys = btree_bset_first(n1)->keys - keys;
|
|
btree_bset_first(n1)->keys = keys;
|
|
|
|
memcpy(btree_bset_first(n2)->start,
|
|
bset_bkey_last(btree_bset_first(n1)),
|
|
btree_bset_first(n2)->keys * sizeof(uint64_t));
|
|
|
|
bkey_copy_key(&n2->key, &b->key);
|
|
|
|
bch_keylist_add(&parent_keys, &n2->key);
|
|
bch_btree_node_write(n2, &cl);
|
|
mutex_unlock(&n2->write_lock);
|
|
rw_unlock(true, n2);
|
|
} else {
|
|
trace_bcache_btree_node_compact(b, btree_bset_first(n1)->keys);
|
|
|
|
mutex_lock(&n1->write_lock);
|
|
bch_btree_insert_keys(n1, op, insert_keys, replace_key);
|
|
}
|
|
|
|
bch_keylist_add(&parent_keys, &n1->key);
|
|
bch_btree_node_write(n1, &cl);
|
|
mutex_unlock(&n1->write_lock);
|
|
|
|
if (n3) {
|
|
/* Depth increases, make a new root */
|
|
mutex_lock(&n3->write_lock);
|
|
bkey_copy_key(&n3->key, &MAX_KEY);
|
|
bch_btree_insert_keys(n3, op, &parent_keys, NULL);
|
|
bch_btree_node_write(n3, &cl);
|
|
mutex_unlock(&n3->write_lock);
|
|
|
|
closure_sync(&cl);
|
|
bch_btree_set_root(n3);
|
|
rw_unlock(true, n3);
|
|
} else if (!b->parent) {
|
|
/* Root filled up but didn't need to be split */
|
|
closure_sync(&cl);
|
|
bch_btree_set_root(n1);
|
|
} else {
|
|
/* Split a non root node */
|
|
closure_sync(&cl);
|
|
make_btree_freeing_key(b, parent_keys.top);
|
|
bch_keylist_push(&parent_keys);
|
|
|
|
bch_btree_insert_node(b->parent, op, &parent_keys, NULL, NULL);
|
|
BUG_ON(!bch_keylist_empty(&parent_keys));
|
|
}
|
|
|
|
btree_node_free(b);
|
|
rw_unlock(true, n1);
|
|
|
|
bch_time_stats_update(&b->c->btree_split_time, start_time);
|
|
|
|
return 0;
|
|
err_free2:
|
|
bkey_put(b->c, &n2->key);
|
|
btree_node_free(n2);
|
|
rw_unlock(true, n2);
|
|
err_free1:
|
|
bkey_put(b->c, &n1->key);
|
|
btree_node_free(n1);
|
|
rw_unlock(true, n1);
|
|
err:
|
|
WARN(1, "bcache: btree split failed (level %u)", b->level);
|
|
|
|
if (n3 == ERR_PTR(-EAGAIN) ||
|
|
n2 == ERR_PTR(-EAGAIN) ||
|
|
n1 == ERR_PTR(-EAGAIN))
|
|
return -EAGAIN;
|
|
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int bch_btree_insert_node(struct btree *b, struct btree_op *op,
|
|
struct keylist *insert_keys,
|
|
atomic_t *journal_ref,
|
|
struct bkey *replace_key)
|
|
{
|
|
struct closure cl;
|
|
|
|
BUG_ON(b->level && replace_key);
|
|
|
|
closure_init_stack(&cl);
|
|
|
|
mutex_lock(&b->write_lock);
|
|
|
|
if (write_block(b) != btree_bset_last(b) &&
|
|
b->keys.last_set_unwritten)
|
|
bch_btree_init_next(b); /* just wrote a set */
|
|
|
|
if (bch_keylist_nkeys(insert_keys) > insert_u64s_remaining(b)) {
|
|
mutex_unlock(&b->write_lock);
|
|
goto split;
|
|
}
|
|
|
|
BUG_ON(write_block(b) != btree_bset_last(b));
|
|
|
|
if (bch_btree_insert_keys(b, op, insert_keys, replace_key)) {
|
|
if (!b->level)
|
|
bch_btree_leaf_dirty(b, journal_ref);
|
|
else
|
|
bch_btree_node_write(b, &cl);
|
|
}
|
|
|
|
mutex_unlock(&b->write_lock);
|
|
|
|
/* wait for btree node write if necessary, after unlock */
|
|
closure_sync(&cl);
|
|
|
|
return 0;
|
|
split:
|
|
if (current->bio_list) {
|
|
op->lock = b->c->root->level + 1;
|
|
return -EAGAIN;
|
|
} else if (op->lock <= b->c->root->level) {
|
|
op->lock = b->c->root->level + 1;
|
|
return -EINTR;
|
|
} else {
|
|
/* Invalidated all iterators */
|
|
int ret = btree_split(b, op, insert_keys, replace_key);
|
|
|
|
if (bch_keylist_empty(insert_keys))
|
|
return 0;
|
|
else if (!ret)
|
|
return -EINTR;
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
int bch_btree_insert_check_key(struct btree *b, struct btree_op *op,
|
|
struct bkey *check_key)
|
|
{
|
|
int ret = -EINTR;
|
|
uint64_t btree_ptr = b->key.ptr[0];
|
|
unsigned long seq = b->seq;
|
|
struct keylist insert;
|
|
bool upgrade = op->lock == -1;
|
|
|
|
bch_keylist_init(&insert);
|
|
|
|
if (upgrade) {
|
|
rw_unlock(false, b);
|
|
rw_lock(true, b, b->level);
|
|
|
|
if (b->key.ptr[0] != btree_ptr ||
|
|
b->seq != seq + 1) {
|
|
op->lock = b->level;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
SET_KEY_PTRS(check_key, 1);
|
|
get_random_bytes(&check_key->ptr[0], sizeof(uint64_t));
|
|
|
|
SET_PTR_DEV(check_key, 0, PTR_CHECK_DEV);
|
|
|
|
bch_keylist_add(&insert, check_key);
|
|
|
|
ret = bch_btree_insert_node(b, op, &insert, NULL, NULL);
|
|
|
|
BUG_ON(!ret && !bch_keylist_empty(&insert));
|
|
out:
|
|
if (upgrade)
|
|
downgrade_write(&b->lock);
|
|
return ret;
|
|
}
|
|
|
|
struct btree_insert_op {
|
|
struct btree_op op;
|
|
struct keylist *keys;
|
|
atomic_t *journal_ref;
|
|
struct bkey *replace_key;
|
|
};
|
|
|
|
static int btree_insert_fn(struct btree_op *b_op, struct btree *b)
|
|
{
|
|
struct btree_insert_op *op = container_of(b_op,
|
|
struct btree_insert_op, op);
|
|
|
|
int ret = bch_btree_insert_node(b, &op->op, op->keys,
|
|
op->journal_ref, op->replace_key);
|
|
if (ret && !bch_keylist_empty(op->keys))
|
|
return ret;
|
|
else
|
|
return MAP_DONE;
|
|
}
|
|
|
|
int bch_btree_insert(struct cache_set *c, struct keylist *keys,
|
|
atomic_t *journal_ref, struct bkey *replace_key)
|
|
{
|
|
struct btree_insert_op op;
|
|
int ret = 0;
|
|
|
|
BUG_ON(current->bio_list);
|
|
BUG_ON(bch_keylist_empty(keys));
|
|
|
|
bch_btree_op_init(&op.op, 0);
|
|
op.keys = keys;
|
|
op.journal_ref = journal_ref;
|
|
op.replace_key = replace_key;
|
|
|
|
while (!ret && !bch_keylist_empty(keys)) {
|
|
op.op.lock = 0;
|
|
ret = bch_btree_map_leaf_nodes(&op.op, c,
|
|
&START_KEY(keys->keys),
|
|
btree_insert_fn);
|
|
}
|
|
|
|
if (ret) {
|
|
struct bkey *k;
|
|
|
|
pr_err("error %i\n", ret);
|
|
|
|
while ((k = bch_keylist_pop(keys)))
|
|
bkey_put(c, k);
|
|
} else if (op.op.insert_collision)
|
|
ret = -ESRCH;
|
|
|
|
return ret;
|
|
}
|
|
|
|
void bch_btree_set_root(struct btree *b)
|
|
{
|
|
unsigned int i;
|
|
struct closure cl;
|
|
|
|
closure_init_stack(&cl);
|
|
|
|
trace_bcache_btree_set_root(b);
|
|
|
|
BUG_ON(!b->written);
|
|
|
|
for (i = 0; i < KEY_PTRS(&b->key); i++)
|
|
BUG_ON(PTR_BUCKET(b->c, &b->key, i)->prio != BTREE_PRIO);
|
|
|
|
mutex_lock(&b->c->bucket_lock);
|
|
list_del_init(&b->list);
|
|
mutex_unlock(&b->c->bucket_lock);
|
|
|
|
b->c->root = b;
|
|
|
|
bch_journal_meta(b->c, &cl);
|
|
closure_sync(&cl);
|
|
}
|
|
|
|
/* Map across nodes or keys */
|
|
|
|
static int bch_btree_map_nodes_recurse(struct btree *b, struct btree_op *op,
|
|
struct bkey *from,
|
|
btree_map_nodes_fn *fn, int flags)
|
|
{
|
|
int ret = MAP_CONTINUE;
|
|
|
|
if (b->level) {
|
|
struct bkey *k;
|
|
struct btree_iter iter;
|
|
|
|
bch_btree_iter_init(&b->keys, &iter, from);
|
|
|
|
while ((k = bch_btree_iter_next_filter(&iter, &b->keys,
|
|
bch_ptr_bad))) {
|
|
ret = bcache_btree(map_nodes_recurse, k, b,
|
|
op, from, fn, flags);
|
|
from = NULL;
|
|
|
|
if (ret != MAP_CONTINUE)
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (!b->level || flags == MAP_ALL_NODES)
|
|
ret = fn(op, b);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int __bch_btree_map_nodes(struct btree_op *op, struct cache_set *c,
|
|
struct bkey *from, btree_map_nodes_fn *fn, int flags)
|
|
{
|
|
return bcache_btree_root(map_nodes_recurse, c, op, from, fn, flags);
|
|
}
|
|
|
|
int bch_btree_map_keys_recurse(struct btree *b, struct btree_op *op,
|
|
struct bkey *from, btree_map_keys_fn *fn,
|
|
int flags)
|
|
{
|
|
int ret = MAP_CONTINUE;
|
|
struct bkey *k;
|
|
struct btree_iter iter;
|
|
|
|
bch_btree_iter_init(&b->keys, &iter, from);
|
|
|
|
while ((k = bch_btree_iter_next_filter(&iter, &b->keys, bch_ptr_bad))) {
|
|
ret = !b->level
|
|
? fn(op, b, k)
|
|
: bcache_btree(map_keys_recurse, k,
|
|
b, op, from, fn, flags);
|
|
from = NULL;
|
|
|
|
if (ret != MAP_CONTINUE)
|
|
return ret;
|
|
}
|
|
|
|
if (!b->level && (flags & MAP_END_KEY))
|
|
ret = fn(op, b, &KEY(KEY_INODE(&b->key),
|
|
KEY_OFFSET(&b->key), 0));
|
|
|
|
return ret;
|
|
}
|
|
|
|
int bch_btree_map_keys(struct btree_op *op, struct cache_set *c,
|
|
struct bkey *from, btree_map_keys_fn *fn, int flags)
|
|
{
|
|
return bcache_btree_root(map_keys_recurse, c, op, from, fn, flags);
|
|
}
|
|
|
|
/* Keybuf code */
|
|
|
|
static inline int keybuf_cmp(struct keybuf_key *l, struct keybuf_key *r)
|
|
{
|
|
/* Overlapping keys compare equal */
|
|
if (bkey_cmp(&l->key, &START_KEY(&r->key)) <= 0)
|
|
return -1;
|
|
if (bkey_cmp(&START_KEY(&l->key), &r->key) >= 0)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static inline int keybuf_nonoverlapping_cmp(struct keybuf_key *l,
|
|
struct keybuf_key *r)
|
|
{
|
|
return clamp_t(int64_t, bkey_cmp(&l->key, &r->key), -1, 1);
|
|
}
|
|
|
|
struct refill {
|
|
struct btree_op op;
|
|
unsigned int nr_found;
|
|
struct keybuf *buf;
|
|
struct bkey *end;
|
|
keybuf_pred_fn *pred;
|
|
};
|
|
|
|
static int refill_keybuf_fn(struct btree_op *op, struct btree *b,
|
|
struct bkey *k)
|
|
{
|
|
struct refill *refill = container_of(op, struct refill, op);
|
|
struct keybuf *buf = refill->buf;
|
|
int ret = MAP_CONTINUE;
|
|
|
|
if (bkey_cmp(k, refill->end) > 0) {
|
|
ret = MAP_DONE;
|
|
goto out;
|
|
}
|
|
|
|
if (!KEY_SIZE(k)) /* end key */
|
|
goto out;
|
|
|
|
if (refill->pred(buf, k)) {
|
|
struct keybuf_key *w;
|
|
|
|
spin_lock(&buf->lock);
|
|
|
|
w = array_alloc(&buf->freelist);
|
|
if (!w) {
|
|
spin_unlock(&buf->lock);
|
|
return MAP_DONE;
|
|
}
|
|
|
|
w->private = NULL;
|
|
bkey_copy(&w->key, k);
|
|
|
|
if (RB_INSERT(&buf->keys, w, node, keybuf_cmp))
|
|
array_free(&buf->freelist, w);
|
|
else
|
|
refill->nr_found++;
|
|
|
|
if (array_freelist_empty(&buf->freelist))
|
|
ret = MAP_DONE;
|
|
|
|
spin_unlock(&buf->lock);
|
|
}
|
|
out:
|
|
buf->last_scanned = *k;
|
|
return ret;
|
|
}
|
|
|
|
void bch_refill_keybuf(struct cache_set *c, struct keybuf *buf,
|
|
struct bkey *end, keybuf_pred_fn *pred)
|
|
{
|
|
struct bkey start = buf->last_scanned;
|
|
struct refill refill;
|
|
|
|
cond_resched();
|
|
|
|
bch_btree_op_init(&refill.op, -1);
|
|
refill.nr_found = 0;
|
|
refill.buf = buf;
|
|
refill.end = end;
|
|
refill.pred = pred;
|
|
|
|
bch_btree_map_keys(&refill.op, c, &buf->last_scanned,
|
|
refill_keybuf_fn, MAP_END_KEY);
|
|
|
|
trace_bcache_keyscan(refill.nr_found,
|
|
KEY_INODE(&start), KEY_OFFSET(&start),
|
|
KEY_INODE(&buf->last_scanned),
|
|
KEY_OFFSET(&buf->last_scanned));
|
|
|
|
spin_lock(&buf->lock);
|
|
|
|
if (!RB_EMPTY_ROOT(&buf->keys)) {
|
|
struct keybuf_key *w;
|
|
|
|
w = RB_FIRST(&buf->keys, struct keybuf_key, node);
|
|
buf->start = START_KEY(&w->key);
|
|
|
|
w = RB_LAST(&buf->keys, struct keybuf_key, node);
|
|
buf->end = w->key;
|
|
} else {
|
|
buf->start = MAX_KEY;
|
|
buf->end = MAX_KEY;
|
|
}
|
|
|
|
spin_unlock(&buf->lock);
|
|
}
|
|
|
|
static void __bch_keybuf_del(struct keybuf *buf, struct keybuf_key *w)
|
|
{
|
|
rb_erase(&w->node, &buf->keys);
|
|
array_free(&buf->freelist, w);
|
|
}
|
|
|
|
void bch_keybuf_del(struct keybuf *buf, struct keybuf_key *w)
|
|
{
|
|
spin_lock(&buf->lock);
|
|
__bch_keybuf_del(buf, w);
|
|
spin_unlock(&buf->lock);
|
|
}
|
|
|
|
bool bch_keybuf_check_overlapping(struct keybuf *buf, struct bkey *start,
|
|
struct bkey *end)
|
|
{
|
|
bool ret = false;
|
|
struct keybuf_key *p, *w, s;
|
|
|
|
s.key = *start;
|
|
|
|
if (bkey_cmp(end, &buf->start) <= 0 ||
|
|
bkey_cmp(start, &buf->end) >= 0)
|
|
return false;
|
|
|
|
spin_lock(&buf->lock);
|
|
w = RB_GREATER(&buf->keys, s, node, keybuf_nonoverlapping_cmp);
|
|
|
|
while (w && bkey_cmp(&START_KEY(&w->key), end) < 0) {
|
|
p = w;
|
|
w = RB_NEXT(w, node);
|
|
|
|
if (p->private)
|
|
ret = true;
|
|
else
|
|
__bch_keybuf_del(buf, p);
|
|
}
|
|
|
|
spin_unlock(&buf->lock);
|
|
return ret;
|
|
}
|
|
|
|
struct keybuf_key *bch_keybuf_next(struct keybuf *buf)
|
|
{
|
|
struct keybuf_key *w;
|
|
|
|
spin_lock(&buf->lock);
|
|
|
|
w = RB_FIRST(&buf->keys, struct keybuf_key, node);
|
|
|
|
while (w && w->private)
|
|
w = RB_NEXT(w, node);
|
|
|
|
if (w)
|
|
w->private = ERR_PTR(-EINTR);
|
|
|
|
spin_unlock(&buf->lock);
|
|
return w;
|
|
}
|
|
|
|
struct keybuf_key *bch_keybuf_next_rescan(struct cache_set *c,
|
|
struct keybuf *buf,
|
|
struct bkey *end,
|
|
keybuf_pred_fn *pred)
|
|
{
|
|
struct keybuf_key *ret;
|
|
|
|
while (1) {
|
|
ret = bch_keybuf_next(buf);
|
|
if (ret)
|
|
break;
|
|
|
|
if (bkey_cmp(&buf->last_scanned, end) >= 0) {
|
|
pr_debug("scan finished\n");
|
|
break;
|
|
}
|
|
|
|
bch_refill_keybuf(c, buf, end, pred);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void bch_keybuf_init(struct keybuf *buf)
|
|
{
|
|
buf->last_scanned = MAX_KEY;
|
|
buf->keys = RB_ROOT;
|
|
|
|
spin_lock_init(&buf->lock);
|
|
array_allocator_init(&buf->freelist);
|
|
}
|
|
|
|
void bch_btree_exit(void)
|
|
{
|
|
if (btree_io_wq)
|
|
destroy_workqueue(btree_io_wq);
|
|
}
|
|
|
|
int __init bch_btree_init(void)
|
|
{
|
|
btree_io_wq = alloc_workqueue("bch_btree_io", WQ_MEM_RECLAIM, 0);
|
|
if (!btree_io_wq)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|