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2783 lines
63 KiB
2783 lines
63 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2010 Kent Overstreet <[email protected]> |
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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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|
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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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|
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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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/* |
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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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|
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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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|
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#define PTR_DIRTY_BIT (((uint64_t) 1 << 36)) |
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|
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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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|
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static struct workqueue_struct *btree_io_wq; |
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|
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#define insert_lock(s, b) ((b)->level <= (s)->lock) |
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|
|
|
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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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} |
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|
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/* Btree key manipulation */ |
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|
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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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|
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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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|
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/* Btree IO */ |
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|
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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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|
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crc = bch_crc64_update(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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/* |
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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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|
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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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|
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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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|
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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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|
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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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|
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bch_btree_iter_push(iter, i->start, bset_bkey_last(i)); |
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|
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b->written += set_blocks(i, block_bytes(b->c->cache)); |
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} |
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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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|
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bch_btree_sort_and_fix_extents(&b->keys, iter, &b->c->sort); |
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|
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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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|
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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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|
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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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|
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closure_put(cl); |
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} |
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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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|
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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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|
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bch_bbio_free(bio, b->c); |
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|
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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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|
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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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|
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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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|
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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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|
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w->prio_blocked = 0; |
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w->journal = NULL; |
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} |
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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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|
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up(&b->io_mutex); |
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} |
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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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|
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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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|
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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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|
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closure_return_with_destructor(cl, btree_node_write_unlock); |
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} |
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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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|
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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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|
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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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|
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if (bio->bi_status) |
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set_btree_node_io_error(b); |
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|
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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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|
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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)); |
|
b->bio->bi_opf = REQ_OP_WRITE | REQ_META | REQ_FUA; |
|
bch_bio_map(b->bio, i); |
|
|
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/* |
|
* If we're appending to a leaf node, we don't technically need FUA - |
|
* 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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* But if we're writing a new btree node (that isn't a root) or |
|
* appending to a non leaf btree node, we need either FUA or a flush |
|
* 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)); |
|
|
|
if (!bch_bio_alloc_pages(b->bio, __GFP_NOWARN|GFP_NOWAIT)) { |
|
struct bio_vec *bv; |
|
void *addr = (void *) ((unsigned long) i & ~(PAGE_SIZE - 1)); |
|
struct bvec_iter_all iter_all; |
|
|
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bio_for_each_segment_all(bv, b->bio, iter_all) { |
|
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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/* |
|
* No problem for multipage bvec since the bio is |
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* just allocated |
|
*/ |
|
b->bio->bi_vcnt = 0; |
|
bch_bio_map(b->bio, i); |
|
|
|
bch_submit_bbio(b->bio, b->c, &k.key, 0); |
|
|
|
closure_sync(cl); |
|
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); |
|
|
|
lockdep_assert_held(&b->write_lock); |
|
|
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trace_bcache_btree_write(b); |
|
|
|
BUG_ON(current->bio_list); |
|
BUG_ON(b->written >= btree_blocks(b)); |
|
BUG_ON(b->written && !i->keys); |
|
BUG_ON(btree_bset_first(b)->seq != i->seq); |
|
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 */ |
|
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); |
|
change_bit(BTREE_NODE_write_idx, &b->flags); |
|
|
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do_btree_node_write(b); |
|
|
|
atomic_long_add(set_blocks(i, block_bytes(b->c->cache)) * b->c->cache->sb.block_size, |
|
&b->c->cache->btree_sectors_written); |
|
|
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b->written += set_blocks(i, block_bytes(b->c->cache)); |
|
} |
|
|
|
void bch_btree_node_write(struct btree *b, struct closure *parent) |
|
{ |
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unsigned int nsets = b->keys.nsets; |
|
|
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lockdep_assert_held(&b->lock); |
|
|
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__bch_btree_node_write(b, parent); |
|
|
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/* |
|
* do verify if there was more than one set initially (i.e. we did a |
|
* sort) and we sorted down to a single set: |
|
*/ |
|
if (nsets && !b->keys.nsets) |
|
bch_btree_verify(b); |
|
|
|
bch_btree_init_next(b); |
|
} |
|
|
|
static void bch_btree_node_write_sync(struct btree *b) |
|
{ |
|
struct closure cl; |
|
|
|
closure_init_stack(&cl); |
|
|
|
mutex_lock(&b->write_lock); |
|
bch_btree_node_write(b, &cl); |
|
mutex_unlock(&b->write_lock); |
|
|
|
closure_sync(&cl); |
|
} |
|
|
|
static void btree_node_write_work(struct work_struct *w) |
|
{ |
|
struct btree *b = container_of(to_delayed_work(w), struct btree, work); |
|
|
|
mutex_lock(&b->write_lock); |
|
if (btree_node_dirty(b)) |
|
__bch_btree_node_write(b, NULL); |
|
mutex_unlock(&b->write_lock); |
|
} |
|
|
|
static void bch_btree_leaf_dirty(struct btree *b, atomic_t *journal_ref) |
|
{ |
|
struct bset *i = btree_bset_last(b); |
|
struct btree_write *w = btree_current_write(b); |
|
|
|
lockdep_assert_held(&b->write_lock); |
|
|
|
BUG_ON(!b->written); |
|
BUG_ON(!i->keys); |
|
|
|
if (!btree_node_dirty(b)) |
|
queue_delayed_work(btree_io_wq, &b->work, 30 * HZ); |
|
|
|
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; |
|
char name[32]; |
|
|
|
/* 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; |
|
|
|
check_state = kzalloc(sizeof(struct btree_check_state), GFP_KERNEL); |
|
if (!check_state) |
|
return -ENOMEM; |
|
|
|
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); |
|
|
|
/* |
|
* 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; |
|
snprintf(name, sizeof(name), "bch_btrchk[%u]", i); |
|
atomic_inc(&check_state->started); |
|
|
|
check_state->infos[i].thread = |
|
kthread_run(bch_btree_check_thread, |
|
&check_state->infos[i], |
|
name); |
|
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; |
|
} |
|
} |
|
|
|
wait_event_interruptible(check_state->wait, |
|
atomic_read(&check_state->started) == 0 || |
|
test_bit(CACHE_SET_IO_DISABLE, &c->flags)); |
|
|
|
for (i = 0; i < check_state->total_threads; i++) { |
|
if (check_state->infos[i].result) { |
|
ret = check_state->infos[i].result; |
|
goto out; |
|
} |
|
} |
|
|
|
out: |
|
kfree(check_state); |
|
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; |
|
}
|
|
|