+// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "btree_cache.h"
#include "btree_iter.h"
#include "btree_locking.h"
#include "debug.h"
-#include "extents.h"
#include <linux/prefetch.h>
+#include <linux/sched/mm.h>
#include <trace/events/bcachefs.h>
-#define DEF_BTREE_ID(kwd, val, name) name,
-
const char * const bch2_btree_ids[] = {
- DEFINE_BCH_BTREE_IDS()
+#define x(kwd, val, name) name,
+ BCH_BTREE_IDS()
+#undef x
NULL
};
-#undef DEF_BTREE_ID
-
void bch2_recalc_btree_reserve(struct bch_fs *c)
{
unsigned i, reserve = 16;
for (i = 0; i < BTREE_ID_NR; i++)
if (c->btree_roots[i].b)
reserve += min_t(unsigned, 1,
- c->btree_roots[i].b->level) * 8;
+ c->btree_roots[i].b->c.level) * 8;
- c->btree_cache_reserve = reserve;
+ c->btree_cache.reserve = reserve;
}
-#define mca_can_free(c) \
- max_t(int, 0, c->btree_cache_used - c->btree_cache_reserve)
+static inline unsigned btree_cache_can_free(struct btree_cache *bc)
+{
+ return max_t(int, 0, bc->used - bc->reserve);
+}
-static void __mca_data_free(struct bch_fs *c, struct btree *b)
+static void __btree_node_data_free(struct bch_fs *c, struct btree *b)
{
EBUG_ON(btree_node_write_in_flight(b));
bch2_btree_keys_free(b);
}
-static void mca_data_free(struct bch_fs *c, struct btree *b)
+static void btree_node_data_free(struct bch_fs *c, struct btree *b)
+{
+ struct btree_cache *bc = &c->btree_cache;
+
+ __btree_node_data_free(c, b);
+ bc->used--;
+ list_move(&b->list, &bc->freed);
+}
+
+static int bch2_btree_cache_cmp_fn(struct rhashtable_compare_arg *arg,
+ const void *obj)
{
- __mca_data_free(c, b);
- c->btree_cache_used--;
- list_move(&b->list, &c->btree_cache_freed);
+ const struct btree *b = obj;
+ const u64 *v = arg->key;
+
+ return b->hash_val == *v ? 0 : 1;
}
static const struct rhashtable_params bch_btree_cache_params = {
.head_offset = offsetof(struct btree, hash),
- .key_offset = offsetof(struct btree, key.v),
- .key_len = sizeof(struct bch_extent_ptr),
+ .key_offset = offsetof(struct btree, hash_val),
+ .key_len = sizeof(u64),
+ .obj_cmpfn = bch2_btree_cache_cmp_fn,
};
-static void mca_data_alloc(struct bch_fs *c, struct btree *b, gfp_t gfp)
+static int __btree_node_data_alloc(struct bch_fs *c, struct btree *b, gfp_t gfp)
{
+ BUG_ON(b->data || b->aux_data);
+
b->data = kvpmalloc(btree_bytes(c), gfp);
if (!b->data)
- goto err;
+ return -ENOMEM;
- if (bch2_btree_keys_alloc(b, btree_page_order(c), gfp))
- goto err;
+ if (bch2_btree_keys_alloc(b, btree_page_order(c), gfp)) {
+ kvpfree(b->data, btree_bytes(c));
+ b->data = NULL;
+ return -ENOMEM;
+ }
- c->btree_cache_used++;
- list_move(&b->list, &c->btree_cache_freeable);
- return;
-err:
- kvpfree(b->data, btree_bytes(c));
- b->data = NULL;
- list_move(&b->list, &c->btree_cache_freed);
+ return 0;
+}
+
+static void btree_node_data_alloc(struct bch_fs *c, struct btree *b, gfp_t gfp)
+{
+ struct btree_cache *bc = &c->btree_cache;
+
+ if (!__btree_node_data_alloc(c, b, gfp)) {
+ bc->used++;
+ list_move(&b->list, &bc->freeable);
+ } else {
+ list_move(&b->list, &bc->freed);
+ }
}
-static struct btree *mca_bucket_alloc(struct bch_fs *c, gfp_t gfp)
+static struct btree *btree_node_mem_alloc(struct bch_fs *c, gfp_t gfp)
{
struct btree *b = kzalloc(sizeof(struct btree), gfp);
if (!b)
return NULL;
- bkey_extent_init(&b->key);
- six_lock_init(&b->lock);
+ bkey_btree_ptr_init(&b->key);
+ six_lock_init(&b->c.lock);
INIT_LIST_HEAD(&b->list);
INIT_LIST_HEAD(&b->write_blocked);
- mca_data_alloc(c, b, gfp);
+ btree_node_data_alloc(c, b, gfp);
return b->data ? b : NULL;
}
/* Btree in memory cache - hash table */
-void bch2_btree_node_hash_remove(struct bch_fs *c, struct btree *b)
+void bch2_btree_node_hash_remove(struct btree_cache *bc, struct btree *b)
{
- rhashtable_remove_fast(&c->btree_cache_table, &b->hash,
- bch_btree_cache_params);
+ rhashtable_remove_fast(&bc->table, &b->hash, bch_btree_cache_params);
/* Cause future lookups for this node to fail: */
- bkey_i_to_extent(&b->key)->v._data[0] = 0;
+ b->hash_val = 0;
}
-int __bch2_btree_node_hash_insert(struct bch_fs *c, struct btree *b)
+int __bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b)
{
- return rhashtable_lookup_insert_fast(&c->btree_cache_table, &b->hash,
+ BUG_ON(b->hash_val);
+ b->hash_val = btree_ptr_hash_val(&b->key);
+
+ return rhashtable_lookup_insert_fast(&bc->table, &b->hash,
bch_btree_cache_params);
}
-int bch2_btree_node_hash_insert(struct bch_fs *c, struct btree *b,
- unsigned level, enum btree_id id)
+int bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b,
+ unsigned level, enum btree_id id)
{
int ret;
- b->level = level;
- b->btree_id = id;
+ b->c.level = level;
+ b->c.btree_id = id;
- mutex_lock(&c->btree_cache_lock);
- ret = __bch2_btree_node_hash_insert(c, b);
+ mutex_lock(&bc->lock);
+ ret = __bch2_btree_node_hash_insert(bc, b);
if (!ret)
- list_add(&b->list, &c->btree_cache);
- mutex_unlock(&c->btree_cache_lock);
+ list_add(&b->list, &bc->live);
+ mutex_unlock(&bc->lock);
return ret;
}
__flatten
-static inline struct btree *mca_find(struct bch_fs *c,
+static inline struct btree *btree_cache_find(struct btree_cache *bc,
const struct bkey_i *k)
{
- return rhashtable_lookup_fast(&c->btree_cache_table, &PTR_HASH(k),
- bch_btree_cache_params);
+ u64 v = btree_ptr_hash_val(k);
+
+ return rhashtable_lookup_fast(&bc->table, &v, bch_btree_cache_params);
}
/*
*/
static int __btree_node_reclaim(struct bch_fs *c, struct btree *b, bool flush)
{
+ struct btree_cache *bc = &c->btree_cache;
int ret = 0;
- lockdep_assert_held(&c->btree_cache_lock);
+ lockdep_assert_held(&bc->lock);
- if (!six_trylock_intent(&b->lock))
+ if (!six_trylock_intent(&b->c.lock))
return -ENOMEM;
- if (!six_trylock_write(&b->lock))
+ if (!six_trylock_write(&b->c.lock))
goto out_unlock_intent;
if (btree_node_noevict(b))
if (!btree_node_may_write(b))
goto out_unlock;
+ if (btree_node_dirty(b) &&
+ test_bit(BCH_FS_HOLD_BTREE_WRITES, &c->flags))
+ goto out_unlock;
+
if (btree_node_dirty(b) ||
btree_node_write_in_flight(b) ||
btree_node_read_in_flight(b)) {
* the post write cleanup:
*/
if (verify_btree_ondisk(c))
- bch2_btree_node_write(c, b, NULL, SIX_LOCK_intent);
+ bch2_btree_node_write(c, b, SIX_LOCK_intent);
else
- __bch2_btree_node_write(c, b, NULL, SIX_LOCK_read);
+ __bch2_btree_node_write(c, b, SIX_LOCK_read);
/* wait for any in flight btree write */
btree_node_wait_on_io(b);
}
out:
- if (PTR_HASH(&b->key))
- trace_btree_node_reap(c, b, ret);
+ if (b->hash_val && !ret)
+ trace_btree_node_reap(c, b);
return ret;
out_unlock:
- six_unlock_write(&b->lock);
+ six_unlock_write(&b->c.lock);
out_unlock_intent:
- six_unlock_intent(&b->lock);
+ six_unlock_intent(&b->c.lock);
ret = -ENOMEM;
goto out;
}
return __btree_node_reclaim(c, b, true);
}
-static unsigned long bch2_mca_scan(struct shrinker *shrink,
- struct shrink_control *sc)
+static unsigned long bch2_btree_cache_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct bch_fs *c = container_of(shrink, struct bch_fs,
- btree_cache_shrink);
+ btree_cache.shrink);
+ struct btree_cache *bc = &c->btree_cache;
struct btree *b, *t;
unsigned long nr = sc->nr_to_scan;
unsigned long can_free;
if (btree_shrinker_disabled(c))
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->btree_cache_lock);
- else if (!mutex_trylock(&c->btree_cache_lock))
+ if (sc->gfp_mask & __GFP_FS)
+ mutex_lock(&bc->lock);
+ else if (!mutex_trylock(&bc->lock))
return -1;
/*
* IO can always make forward progress:
*/
nr /= btree_pages(c);
- can_free = mca_can_free(c);
+ can_free = btree_cache_can_free(bc);
nr = min_t(unsigned long, nr, can_free);
i = 0;
- list_for_each_entry_safe(b, t, &c->btree_cache_freeable, list) {
+ list_for_each_entry_safe(b, t, &bc->freeable, list) {
touched++;
if (freed >= nr)
if (++i > 3 &&
!btree_node_reclaim(c, b)) {
- mca_data_free(c, b);
- six_unlock_write(&b->lock);
- six_unlock_intent(&b->lock);
+ btree_node_data_free(c, b);
+ six_unlock_write(&b->c.lock);
+ six_unlock_intent(&b->c.lock);
freed++;
}
}
restart:
- list_for_each_entry_safe(b, t, &c->btree_cache, list) {
+ list_for_each_entry_safe(b, t, &bc->live, list) {
touched++;
if (freed >= nr) {
/* Save position */
- if (&t->list != &c->btree_cache)
- list_move_tail(&c->btree_cache, &t->list);
+ if (&t->list != &bc->live)
+ list_move_tail(&bc->live, &t->list);
break;
}
if (!btree_node_accessed(b) &&
!btree_node_reclaim(c, b)) {
- /* can't call bch2_btree_node_hash_remove under btree_cache_lock */
+ /* can't call bch2_btree_node_hash_remove under lock */
freed++;
- if (&t->list != &c->btree_cache)
- list_move_tail(&c->btree_cache, &t->list);
+ if (&t->list != &bc->live)
+ list_move_tail(&bc->live, &t->list);
- mca_data_free(c, b);
- mutex_unlock(&c->btree_cache_lock);
+ btree_node_data_free(c, b);
+ mutex_unlock(&bc->lock);
- bch2_btree_node_hash_remove(c, b);
- six_unlock_write(&b->lock);
- six_unlock_intent(&b->lock);
+ bch2_btree_node_hash_remove(bc, b);
+ six_unlock_write(&b->c.lock);
+ six_unlock_intent(&b->c.lock);
if (freed >= nr)
goto out;
if (sc->gfp_mask & __GFP_IO)
- mutex_lock(&c->btree_cache_lock);
- else if (!mutex_trylock(&c->btree_cache_lock))
+ mutex_lock(&bc->lock);
+ else if (!mutex_trylock(&bc->lock))
goto out;
goto restart;
} else
clear_btree_node_accessed(b);
}
- mutex_unlock(&c->btree_cache_lock);
+ mutex_unlock(&bc->lock);
out:
return (unsigned long) freed * btree_pages(c);
}
-static unsigned long bch2_mca_count(struct shrinker *shrink,
- struct shrink_control *sc)
+static unsigned long bch2_btree_cache_count(struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct bch_fs *c = container_of(shrink, struct bch_fs,
- btree_cache_shrink);
+ btree_cache.shrink);
+ struct btree_cache *bc = &c->btree_cache;
if (btree_shrinker_disabled(c))
return 0;
- if (c->btree_cache_alloc_lock)
- return 0;
-
- return mca_can_free(c) * btree_pages(c);
+ return btree_cache_can_free(bc) * btree_pages(c);
}
-void bch2_fs_btree_exit(struct bch_fs *c)
+void bch2_fs_btree_cache_exit(struct bch_fs *c)
{
+ struct btree_cache *bc = &c->btree_cache;
struct btree *b;
unsigned i;
- if (c->btree_cache_shrink.list.next)
- unregister_shrinker(&c->btree_cache_shrink);
+ if (bc->shrink.list.next)
+ unregister_shrinker(&bc->shrink);
- mutex_lock(&c->btree_cache_lock);
+ mutex_lock(&bc->lock);
#ifdef CONFIG_BCACHEFS_DEBUG
if (c->verify_data)
- list_move(&c->verify_data->list, &c->btree_cache);
+ list_move(&c->verify_data->list, &bc->live);
kvpfree(c->verify_ondisk, btree_bytes(c));
#endif
for (i = 0; i < BTREE_ID_NR; i++)
if (c->btree_roots[i].b)
- list_add(&c->btree_roots[i].b->list, &c->btree_cache);
+ list_add(&c->btree_roots[i].b->list, &bc->live);
+
+ list_splice(&bc->freeable, &bc->live);
- list_splice(&c->btree_cache_freeable,
- &c->btree_cache);
+ while (!list_empty(&bc->live)) {
+ b = list_first_entry(&bc->live, struct btree, list);
- while (!list_empty(&c->btree_cache)) {
- b = list_first_entry(&c->btree_cache, struct btree, list);
+ BUG_ON(btree_node_read_in_flight(b) ||
+ btree_node_write_in_flight(b));
if (btree_node_dirty(b))
bch2_btree_complete_write(c, b, btree_current_write(b));
clear_btree_node_dirty(b);
- mca_data_free(c, b);
+ btree_node_data_free(c, b);
}
- while (!list_empty(&c->btree_cache_freed)) {
- b = list_first_entry(&c->btree_cache_freed,
- struct btree, list);
+ while (!list_empty(&bc->freed)) {
+ b = list_first_entry(&bc->freed, struct btree, list);
list_del(&b->list);
kfree(b);
}
- mutex_unlock(&c->btree_cache_lock);
+ mutex_unlock(&bc->lock);
- if (c->btree_cache_table_init_done)
- rhashtable_destroy(&c->btree_cache_table);
+ if (bc->table_init_done)
+ rhashtable_destroy(&bc->table);
}
-int bch2_fs_btree_init(struct bch_fs *c)
+int bch2_fs_btree_cache_init(struct bch_fs *c)
{
+ struct btree_cache *bc = &c->btree_cache;
unsigned i;
- int ret;
+ int ret = 0;
+
+ pr_verbose_init(c->opts, "");
- ret = rhashtable_init(&c->btree_cache_table, &bch_btree_cache_params);
+ ret = rhashtable_init(&bc->table, &bch_btree_cache_params);
if (ret)
- return ret;
+ goto out;
- c->btree_cache_table_init_done = true;
+ bc->table_init_done = true;
bch2_recalc_btree_reserve(c);
- for (i = 0; i < c->btree_cache_reserve; i++)
- if (!mca_bucket_alloc(c, GFP_KERNEL))
- return -ENOMEM;
+ for (i = 0; i < bc->reserve; i++)
+ if (!btree_node_mem_alloc(c, GFP_KERNEL)) {
+ ret = -ENOMEM;
+ goto out;
+ }
- list_splice_init(&c->btree_cache,
- &c->btree_cache_freeable);
+ list_splice_init(&bc->live, &bc->freeable);
#ifdef CONFIG_BCACHEFS_DEBUG
mutex_init(&c->verify_lock);
c->verify_ondisk = kvpmalloc(btree_bytes(c), GFP_KERNEL);
- if (!c->verify_ondisk)
- return -ENOMEM;
+ if (!c->verify_ondisk) {
+ ret = -ENOMEM;
+ goto out;
+ }
- c->verify_data = mca_bucket_alloc(c, GFP_KERNEL);
- if (!c->verify_data)
- return -ENOMEM;
+ c->verify_data = btree_node_mem_alloc(c, GFP_KERNEL);
+ if (!c->verify_data) {
+ ret = -ENOMEM;
+ goto out;
+ }
list_del_init(&c->verify_data->list);
#endif
- c->btree_cache_shrink.count_objects = bch2_mca_count;
- c->btree_cache_shrink.scan_objects = bch2_mca_scan;
- c->btree_cache_shrink.seeks = 4;
- c->btree_cache_shrink.batch = btree_pages(c) * 2;
- register_shrinker(&c->btree_cache_shrink);
+ bc->shrink.count_objects = bch2_btree_cache_count;
+ bc->shrink.scan_objects = bch2_btree_cache_scan;
+ bc->shrink.seeks = 4;
+ bc->shrink.batch = btree_pages(c) * 2;
+ register_shrinker(&bc->shrink);
+out:
+ pr_verbose_init(c->opts, "ret %i", ret);
+ return ret;
+}
- return 0;
+void bch2_fs_btree_cache_init_early(struct btree_cache *bc)
+{
+ mutex_init(&bc->lock);
+ INIT_LIST_HEAD(&bc->live);
+ INIT_LIST_HEAD(&bc->freeable);
+ INIT_LIST_HEAD(&bc->freed);
}
/*
* 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.
*/
-void bch2_btree_node_cannibalize_unlock(struct bch_fs *c)
+void bch2_btree_cache_cannibalize_unlock(struct bch_fs *c)
{
- if (c->btree_cache_alloc_lock == current) {
+ struct btree_cache *bc = &c->btree_cache;
+
+ if (bc->alloc_lock == current) {
trace_btree_node_cannibalize_unlock(c);
- c->btree_cache_alloc_lock = NULL;
- closure_wake_up(&c->mca_wait);
+ bc->alloc_lock = NULL;
+ closure_wake_up(&bc->alloc_wait);
}
}
-int bch2_btree_node_cannibalize_lock(struct bch_fs *c, struct closure *cl)
+int bch2_btree_cache_cannibalize_lock(struct bch_fs *c, struct closure *cl)
{
+ struct btree_cache *bc = &c->btree_cache;
struct task_struct *old;
- old = cmpxchg(&c->btree_cache_alloc_lock, NULL, current);
+ old = cmpxchg(&bc->alloc_lock, NULL, current);
if (old == NULL || old == current)
goto success;
return -ENOMEM;
}
- closure_wait(&c->mca_wait, cl);
+ closure_wait(&bc->alloc_wait, cl);
/* Try again, after adding ourselves to waitlist */
- old = cmpxchg(&c->btree_cache_alloc_lock, NULL, current);
+ old = cmpxchg(&bc->alloc_lock, NULL, current);
if (old == NULL || old == current) {
/* We raced */
- closure_wake_up(&c->mca_wait);
+ closure_wake_up(&bc->alloc_wait);
goto success;
}
return 0;
}
-static struct btree *mca_cannibalize(struct bch_fs *c)
+static struct btree *btree_node_cannibalize(struct bch_fs *c)
{
+ struct btree_cache *bc = &c->btree_cache;
struct btree *b;
- list_for_each_entry_reverse(b, &c->btree_cache, list)
+ list_for_each_entry_reverse(b, &bc->live, list)
if (!btree_node_reclaim(c, b))
return b;
while (1) {
- list_for_each_entry_reverse(b, &c->btree_cache, list)
+ list_for_each_entry_reverse(b, &bc->live, list)
if (!btree_node_write_and_reclaim(c, b))
return b;
struct btree *bch2_btree_node_mem_alloc(struct bch_fs *c)
{
+ struct btree_cache *bc = &c->btree_cache;
struct btree *b;
u64 start_time = local_clock();
+ unsigned flags;
- mutex_lock(&c->btree_cache_lock);
+ flags = memalloc_nofs_save();
+ mutex_lock(&bc->lock);
/*
* 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)
+ list_for_each_entry(b, &bc->freeable, list)
if (!btree_node_reclaim(c, b))
- goto out_unlock;
+ goto got_node;
/*
* 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 (!btree_node_reclaim(c, b)) {
- mca_data_alloc(c, b, __GFP_NOWARN|GFP_NOIO);
- if (b->data)
- goto out_unlock;
-
- six_unlock_write(&b->lock);
- six_unlock_intent(&b->lock);
+ list_for_each_entry(b, &bc->freed, list)
+ if (!btree_node_reclaim(c, b))
+ goto got_node;
+
+ b = NULL;
+got_node:
+ if (b)
+ list_del_init(&b->list);
+ mutex_unlock(&bc->lock);
+
+ if (!b) {
+ b = kzalloc(sizeof(struct btree), GFP_KERNEL);
+ if (!b)
goto err;
- }
- b = mca_bucket_alloc(c, __GFP_NOWARN|GFP_NOIO);
- if (!b)
- goto err;
+ bkey_btree_ptr_init(&b->key);
+ six_lock_init(&b->c.lock);
+ INIT_LIST_HEAD(&b->list);
+ INIT_LIST_HEAD(&b->write_blocked);
+
+ BUG_ON(!six_trylock_intent(&b->c.lock));
+ BUG_ON(!six_trylock_write(&b->c.lock));
+ }
+
+ if (!b->data) {
+ if (__btree_node_data_alloc(c, b, __GFP_NOWARN|GFP_KERNEL))
+ goto err;
+
+ mutex_lock(&bc->lock);
+ bc->used++;
+ mutex_unlock(&bc->lock);
+ }
- BUG_ON(!six_trylock_intent(&b->lock));
- BUG_ON(!six_trylock_write(&b->lock));
-out_unlock:
BUG_ON(btree_node_hashed(b));
BUG_ON(btree_node_write_in_flight(b));
-
- list_del_init(&b->list);
- mutex_unlock(&c->btree_cache_lock);
out:
b->flags = 0;
b->written = 0;
b->sib_u64s[0] = 0;
b->sib_u64s[1] = 0;
b->whiteout_u64s = 0;
- b->uncompacted_whiteout_u64s = 0;
bch2_btree_keys_init(b, &c->expensive_debug_checks);
- bch2_time_stats_update(&c->btree_node_mem_alloc_time, start_time);
+ bch2_time_stats_update(&c->times[BCH_TIME_btree_node_mem_alloc],
+ start_time);
+ memalloc_nofs_restore(flags);
return b;
err:
+ mutex_lock(&bc->lock);
+
+ if (b) {
+ list_add(&b->list, &bc->freed);
+ six_unlock_write(&b->c.lock);
+ six_unlock_intent(&b->c.lock);
+ }
+
/* Try to cannibalize another cached btree node: */
- if (c->btree_cache_alloc_lock == current) {
- b = mca_cannibalize(c);
+ if (bc->alloc_lock == current) {
+ b = btree_node_cannibalize(c);
list_del_init(&b->list);
- mutex_unlock(&c->btree_cache_lock);
+ mutex_unlock(&bc->lock);
- bch2_btree_node_hash_remove(c, b);
+ bch2_btree_node_hash_remove(bc, b);
trace_btree_node_cannibalize(c);
goto out;
}
- mutex_unlock(&c->btree_cache_lock);
+ mutex_unlock(&bc->lock);
+ memalloc_nofs_restore(flags);
return ERR_PTR(-ENOMEM);
}
/* Slowpath, don't want it inlined into btree_iter_traverse() */
-static noinline struct btree *bch2_btree_node_fill(struct btree_iter *iter,
- const struct bkey_i *k,
- unsigned level,
- enum six_lock_type lock_type)
+static noinline struct btree *bch2_btree_node_fill(struct bch_fs *c,
+ struct btree_iter *iter,
+ const struct bkey_i *k,
+ enum btree_id btree_id,
+ unsigned level,
+ enum six_lock_type lock_type,
+ bool sync)
{
- struct bch_fs *c = iter->c;
+ struct btree_cache *bc = &c->btree_cache;
struct btree *b;
+ BUG_ON(level + 1 >= BTREE_MAX_DEPTH);
/*
* Parent node must be locked, else we could read in a btree node that's
* been freed:
*/
- BUG_ON(!btree_node_locked(iter, level + 1));
+ if (iter && !bch2_btree_node_relock(iter, level + 1))
+ return ERR_PTR(-EINTR);
b = bch2_btree_node_mem_alloc(c);
if (IS_ERR(b))
return b;
bkey_copy(&b->key, k);
- if (bch2_btree_node_hash_insert(c, b, level, iter->btree_id)) {
+ if (bch2_btree_node_hash_insert(bc, b, level, btree_id)) {
/* raced with another fill: */
/* mark as unhashed... */
- bkey_i_to_extent(&b->key)->v._data[0] = 0;
+ b->hash_val = 0;
- mutex_lock(&c->btree_cache_lock);
- list_add(&b->list, &c->btree_cache_freeable);
- mutex_unlock(&c->btree_cache_lock);
+ mutex_lock(&bc->lock);
+ list_add(&b->list, &bc->freeable);
+ mutex_unlock(&bc->lock);
- six_unlock_write(&b->lock);
- six_unlock_intent(&b->lock);
+ six_unlock_write(&b->c.lock);
+ six_unlock_intent(&b->c.lock);
return NULL;
}
/*
- * If the btree node wasn't cached, we can't drop our lock on
- * the parent until after it's added to the cache - because
- * otherwise we could race with a btree_split() freeing the node
- * we're trying to lock.
+ * Unlock before doing IO:
*
- * But the deadlock described below doesn't exist in this case,
- * so it's safe to not drop the parent lock until here:
+ * XXX: ideally should be dropping all btree node locks here
*/
- if (btree_node_read_locked(iter, level + 1))
+ if (iter && btree_node_read_locked(iter, level + 1))
btree_node_unlock(iter, level + 1);
- bch2_btree_node_read(c, b, true);
- six_unlock_write(&b->lock);
+ bch2_btree_node_read(c, b, sync);
+
+ six_unlock_write(&b->c.lock);
+
+ if (!sync) {
+ six_unlock_intent(&b->c.lock);
+ return NULL;
+ }
if (lock_type == SIX_LOCK_read)
- six_lock_downgrade(&b->lock);
+ six_lock_downgrade(&b->c.lock);
return b;
}
+static int lock_node_check_fn(struct six_lock *lock, void *p)
+{
+ struct btree *b = container_of(lock, struct btree, c.lock);
+ const struct bkey_i *k = p;
+
+ return b->hash_val == btree_ptr_hash_val(k) ? 0 : -1;
+}
+
/**
* bch_btree_node_get - find a btree node in the cache and lock it, reading it
* in from disk if necessary.
* The btree node will have either a read or a write lock held, depending on
* the @write parameter.
*/
-struct btree *bch2_btree_node_get(struct btree_iter *iter,
+struct btree *bch2_btree_node_get(struct bch_fs *c, struct btree_iter *iter,
const struct bkey_i *k, unsigned level,
enum six_lock_type lock_type)
{
+ struct btree_cache *bc = &c->btree_cache;
struct btree *b;
struct bset_tree *t;
- BUG_ON(level >= BTREE_MAX_DEPTH);
-retry:
- rcu_read_lock();
- b = mca_find(iter->c, k);
- rcu_read_unlock();
+ EBUG_ON(level >= BTREE_MAX_DEPTH);
+ b = btree_node_mem_ptr(k);
+ if (b)
+ goto lock_node;
+retry:
+ b = btree_cache_find(bc, k);
if (unlikely(!b)) {
/*
* We must have the parent locked to call bch2_btree_node_fill(),
* else we could read in a btree node from disk that's been
* freed:
*/
- b = bch2_btree_node_fill(iter, k, level, lock_type);
+ b = bch2_btree_node_fill(c, iter, k, iter->btree_id,
+ level, lock_type, true);
/* We raced and found the btree node in the cache */
if (!b)
if (IS_ERR(b))
return b;
} else {
+lock_node:
/*
* There's a potential deadlock with splits and insertions into
* interior nodes we have to avoid:
* free it:
*
* To guard against this, btree nodes are evicted from the cache
- * when they're freed - and PTR_HASH() is zeroed out, which we
+ * when they're freed - and b->hash_val is zeroed out, which we
* check for after we lock the node.
*
* Then, bch2_btree_node_relock() on the parent will fail - because
if (btree_node_read_locked(iter, level + 1))
btree_node_unlock(iter, level + 1);
- if (!btree_node_lock(b, k->k.p, level, iter, lock_type))
+ if (!btree_node_lock(b, k->k.p, level, iter, lock_type,
+ lock_node_check_fn, (void *) k)) {
+ if (b->hash_val != btree_ptr_hash_val(k))
+ goto retry;
return ERR_PTR(-EINTR);
+ }
- if (unlikely(PTR_HASH(&b->key) != PTR_HASH(k) ||
- b->level != level ||
+ if (unlikely(b->hash_val != btree_ptr_hash_val(k) ||
+ b->c.level != level ||
race_fault())) {
- six_unlock_type(&b->lock, lock_type);
+ six_unlock_type(&b->c.lock, lock_type);
if (bch2_btree_node_relock(iter, level + 1))
goto retry;
+ trace_trans_restart_btree_node_reused(iter->trans->ip);
return ERR_PTR(-EINTR);
}
}
+ /* XXX: waiting on IO with btree locks held: */
wait_on_bit_io(&b->flags, BTREE_NODE_read_in_flight,
TASK_UNINTERRUPTIBLE);
}
/* avoid atomic set bit if it's not needed: */
- if (btree_node_accessed(b))
+ if (!btree_node_accessed(b))
set_btree_node_accessed(b);
if (unlikely(btree_node_read_error(b))) {
- six_unlock_type(&b->lock, lock_type);
+ six_unlock_type(&b->c.lock, lock_type);
return ERR_PTR(-EIO);
}
- EBUG_ON(!b->written);
- EBUG_ON(b->btree_id != iter->btree_id ||
+ EBUG_ON(b->c.btree_id != iter->btree_id ||
BTREE_NODE_LEVEL(b->data) != level ||
bkey_cmp(b->data->max_key, k->k.p));
return b;
}
-void bch2_btree_node_prefetch(struct btree_iter *iter,
- const struct bkey_i *k, unsigned level)
+struct btree *bch2_btree_node_get_noiter(struct bch_fs *c,
+ const struct bkey_i *k,
+ enum btree_id btree_id,
+ unsigned level)
{
- struct bch_fs *c = iter->c;
+ struct btree_cache *bc = &c->btree_cache;
struct btree *b;
+ struct bset_tree *t;
+ int ret;
- BUG_ON(level >= BTREE_MAX_DEPTH);
-
- rcu_read_lock();
- b = mca_find(c, k);
- rcu_read_unlock();
+ EBUG_ON(level >= BTREE_MAX_DEPTH);
+ b = btree_node_mem_ptr(k);
if (b)
- return;
+ goto lock_node;
+retry:
+ b = btree_cache_find(bc, k);
+ if (unlikely(!b)) {
+ b = bch2_btree_node_fill(c, NULL, k, btree_id,
+ level, SIX_LOCK_read, true);
- b = bch2_btree_node_mem_alloc(c);
- if (IS_ERR(b))
- return;
+ /* We raced and found the btree node in the cache */
+ if (!b)
+ goto retry;
- bkey_copy(&b->key, k);
- if (bch2_btree_node_hash_insert(c, b, level, iter->btree_id)) {
- /* raced with another fill: */
+ if (IS_ERR(b))
+ return b;
+ } else {
+lock_node:
+ ret = six_lock_read(&b->c.lock, lock_node_check_fn, (void *) k);
+ if (ret)
+ goto retry;
- /* mark as unhashed... */
- bkey_i_to_extent(&b->key)->v._data[0] = 0;
+ if (unlikely(b->hash_val != btree_ptr_hash_val(k) ||
+ b->c.btree_id != btree_id ||
+ b->c.level != level)) {
+ six_unlock_read(&b->c.lock);
+ goto retry;
+ }
+ }
+
+ /* XXX: waiting on IO with btree locks held: */
+ wait_on_bit_io(&b->flags, BTREE_NODE_read_in_flight,
+ TASK_UNINTERRUPTIBLE);
+
+ prefetch(b->aux_data);
+
+ for_each_bset(b, t) {
+ void *p = (u64 *) b->aux_data + t->aux_data_offset;
+
+ prefetch(p + L1_CACHE_BYTES * 0);
+ prefetch(p + L1_CACHE_BYTES * 1);
+ prefetch(p + L1_CACHE_BYTES * 2);
+ }
+
+ /* avoid atomic set bit if it's not needed: */
+ if (!btree_node_accessed(b))
+ set_btree_node_accessed(b);
+
+ if (unlikely(btree_node_read_error(b))) {
+ six_unlock_read(&b->c.lock);
+ return ERR_PTR(-EIO);
+ }
+
+ EBUG_ON(b->c.btree_id != btree_id ||
+ BTREE_NODE_LEVEL(b->data) != level ||
+ bkey_cmp(b->data->max_key, k->k.p));
+
+ return b;
+}
+
+struct btree *bch2_btree_node_get_sibling(struct bch_fs *c,
+ struct btree_iter *iter,
+ struct btree *b,
+ enum btree_node_sibling sib)
+{
+ struct btree_trans *trans = iter->trans;
+ struct btree *parent;
+ struct btree_node_iter node_iter;
+ struct bkey_packed *k;
+ BKEY_PADDED(k) tmp;
+ struct btree *ret = NULL;
+ unsigned level = b->c.level;
+
+ parent = btree_iter_node(iter, level + 1);
+ if (!parent)
+ return NULL;
+
+ /*
+ * There's a corner case where a btree_iter might have a node locked
+ * that is just outside its current pos - when
+ * bch2_btree_iter_set_pos_same_leaf() gets to the end of the node.
+ *
+ * But the lock ordering checks in __bch2_btree_node_lock() go off of
+ * iter->pos, not the node's key: so if the iterator is marked as
+ * needing to be traversed, we risk deadlock if we don't bail out here:
+ */
+ if (iter->uptodate >= BTREE_ITER_NEED_TRAVERSE)
+ return ERR_PTR(-EINTR);
- mutex_lock(&c->btree_cache_lock);
- list_add(&b->list, &c->btree_cache_freeable);
- mutex_unlock(&c->btree_cache_lock);
+ if (!bch2_btree_node_relock(iter, level + 1)) {
+ ret = ERR_PTR(-EINTR);
goto out;
}
- bch2_btree_node_read(c, b, false);
+ node_iter = iter->l[parent->c.level].iter;
+
+ k = bch2_btree_node_iter_peek_all(&node_iter, parent);
+ BUG_ON(bkey_cmp_left_packed(parent, k, &b->key.k.p));
+
+ k = sib == btree_prev_sib
+ ? bch2_btree_node_iter_prev(&node_iter, parent)
+ : (bch2_btree_node_iter_advance(&node_iter, parent),
+ bch2_btree_node_iter_peek(&node_iter, parent));
+ if (!k)
+ goto out;
+
+ bch2_bkey_unpack(parent, &tmp.k, k);
+
+ ret = bch2_btree_node_get(c, iter, &tmp.k, level,
+ SIX_LOCK_intent);
+
+ if (PTR_ERR_OR_ZERO(ret) == -EINTR && !trans->nounlock) {
+ struct btree_iter *linked;
+
+ if (!bch2_btree_node_relock(iter, level + 1))
+ goto out;
+
+ /*
+ * We might have got -EINTR because trylock failed, and we're
+ * holding other locks that would cause us to deadlock:
+ */
+ trans_for_each_iter(trans, linked)
+ if (btree_iter_cmp(iter, linked) < 0)
+ __bch2_btree_iter_unlock(linked);
+
+ if (sib == btree_prev_sib)
+ btree_node_unlock(iter, level);
+
+ ret = bch2_btree_node_get(c, iter, &tmp.k, level,
+ SIX_LOCK_intent);
+
+ /*
+ * before btree_iter_relock() calls btree_iter_verify_locks():
+ */
+ if (btree_lock_want(iter, level + 1) == BTREE_NODE_UNLOCKED)
+ btree_node_unlock(iter, level + 1);
+
+ if (!bch2_btree_node_relock(iter, level)) {
+ btree_iter_set_dirty(iter, BTREE_ITER_NEED_RELOCK);
+
+ if (!IS_ERR(ret)) {
+ six_unlock_intent(&ret->c.lock);
+ ret = ERR_PTR(-EINTR);
+ }
+ }
+
+ bch2_trans_relock(trans);
+ }
out:
- six_unlock_write(&b->lock);
- six_unlock_intent(&b->lock);
+ if (btree_lock_want(iter, level + 1) == BTREE_NODE_UNLOCKED)
+ btree_node_unlock(iter, level + 1);
+
+ if (PTR_ERR_OR_ZERO(ret) == -EINTR)
+ bch2_btree_iter_upgrade(iter, level + 2);
+
+ BUG_ON(!IS_ERR(ret) && !btree_node_locked(iter, level));
+
+ if (!IS_ERR_OR_NULL(ret)) {
+ struct btree *n1 = ret, *n2 = b;
+
+ if (sib != btree_prev_sib)
+ swap(n1, n2);
+
+ BUG_ON(bkey_cmp(bkey_successor(n1->key.k.p),
+ n2->data->min_key));
+ }
+
+ bch2_btree_trans_verify_locks(trans);
+
+ return ret;
+}
+
+void bch2_btree_node_prefetch(struct bch_fs *c, struct btree_iter *iter,
+ const struct bkey_i *k, unsigned level)
+{
+ struct btree_cache *bc = &c->btree_cache;
+ struct btree *b;
+
+ BUG_ON(!btree_node_locked(iter, level + 1));
+ BUG_ON(level >= BTREE_MAX_DEPTH);
+
+ b = btree_cache_find(bc, k);
+ if (b)
+ return;
+
+ bch2_btree_node_fill(c, iter, k, iter->btree_id,
+ level, SIX_LOCK_read, false);
}
-int bch2_print_btree_node(struct bch_fs *c, struct btree *b,
- char *buf, size_t len)
+void bch2_btree_node_to_text(struct printbuf *out, struct bch_fs *c,
+ struct btree *b)
{
const struct bkey_format *f = &b->format;
struct bset_stats stats;
- char ptrs[100];
memset(&stats, 0, sizeof(stats));
- bch2_val_to_text(c, BKEY_TYPE_BTREE, ptrs, sizeof(ptrs),
- bkey_i_to_s_c(&b->key));
bch2_btree_keys_stats(b, &stats);
- return scnprintf(buf, len,
- "l %u %llu:%llu - %llu:%llu:\n"
- " ptrs: %s\n"
- " format: u64s %u fields %u %u %u %u %u\n"
- " unpack fn len: %u\n"
- " bytes used %zu/%zu (%zu%% full)\n"
- " sib u64s: %u, %u (merge threshold %zu)\n"
- " nr packed keys %u\n"
- " nr unpacked keys %u\n"
- " floats %zu\n"
- " failed unpacked %zu\n"
- " failed prev %zu\n"
- " failed overflow %zu\n",
- b->level,
- b->data->min_key.inode,
- b->data->min_key.offset,
- b->data->max_key.inode,
- b->data->max_key.offset,
- ptrs,
- f->key_u64s,
- f->bits_per_field[0],
- f->bits_per_field[1],
- f->bits_per_field[2],
- f->bits_per_field[3],
- f->bits_per_field[4],
- b->unpack_fn_len,
- b->nr.live_u64s * sizeof(u64),
- btree_bytes(c) - sizeof(struct btree_node),
- b->nr.live_u64s * 100 / btree_max_u64s(c),
- b->sib_u64s[0],
- b->sib_u64s[1],
- BTREE_FOREGROUND_MERGE_THRESHOLD(c),
- b->nr.packed_keys,
- b->nr.unpacked_keys,
- stats.floats,
- stats.failed_unpacked,
- stats.failed_prev,
- stats.failed_overflow);
+ pr_buf(out,
+ "l %u %llu:%llu - %llu:%llu:\n"
+ " ptrs: ",
+ b->c.level,
+ b->data->min_key.inode,
+ b->data->min_key.offset,
+ b->data->max_key.inode,
+ b->data->max_key.offset);
+ bch2_val_to_text(out, c, bkey_i_to_s_c(&b->key));
+ pr_buf(out, "\n"
+ " format: u64s %u fields %u %u %u %u %u\n"
+ " unpack fn len: %u\n"
+ " bytes used %zu/%zu (%zu%% full)\n"
+ " sib u64s: %u, %u (merge threshold %zu)\n"
+ " nr packed keys %u\n"
+ " nr unpacked keys %u\n"
+ " floats %zu\n"
+ " failed unpacked %zu\n",
+ f->key_u64s,
+ f->bits_per_field[0],
+ f->bits_per_field[1],
+ f->bits_per_field[2],
+ f->bits_per_field[3],
+ f->bits_per_field[4],
+ b->unpack_fn_len,
+ b->nr.live_u64s * sizeof(u64),
+ btree_bytes(c) - sizeof(struct btree_node),
+ b->nr.live_u64s * 100 / btree_max_u64s(c),
+ b->sib_u64s[0],
+ b->sib_u64s[1],
+ BTREE_FOREGROUND_MERGE_THRESHOLD(c),
+ b->nr.packed_keys,
+ b->nr.unpacked_keys,
+ stats.floats,
+ stats.failed);
}