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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_BTREE_UPDATE_INTERIOR_H
#define _BCACHEFS_BTREE_UPDATE_INTERIOR_H
#include "btree_cache.h"
#include "btree_locking.h"
#include "btree_update.h"
#define BTREE_UPDATE_NODES_MAX ((BTREE_MAX_DEPTH - 2) * 2 + GC_MERGE_NODES)
#define BTREE_UPDATE_JOURNAL_RES (BTREE_UPDATE_NODES_MAX * (BKEY_BTREE_PTR_U64s_MAX + 1))
/*
* Tracks an in progress split/rewrite of a btree node and the update to the
* parent node:
*
* When we split/rewrite a node, we do all the updates in memory without
* waiting for any writes to complete - we allocate the new node(s) and update
* the parent node, possibly recursively up to the root.
*
* The end result is that we have one or more new nodes being written -
* possibly several, if there were multiple splits - and then a write (updating
* an interior node) which will make all these new nodes visible.
*
* Additionally, as we split/rewrite nodes we free the old nodes - but the old
* nodes can't be freed (their space on disk can't be reclaimed) until the
* update to the interior node that makes the new node visible completes -
* until then, the old nodes are still reachable on disk.
*
*/
struct btree_update {
struct closure cl;
struct bch_fs *c;
u64 start_time;
struct list_head list;
struct list_head unwritten_list;
/* What kind of update are we doing? */
enum {
BTREE_INTERIOR_NO_UPDATE,
BTREE_INTERIOR_UPDATING_NODE,
BTREE_INTERIOR_UPDATING_ROOT,
BTREE_INTERIOR_UPDATING_AS,
} mode;
unsigned nodes_written:1;
unsigned took_gc_lock:1;
enum btree_id btree_id;
unsigned update_level;
struct disk_reservation disk_res;
/*
* BTREE_INTERIOR_UPDATING_NODE:
* The update that made the new nodes visible was a regular update to an
* existing interior node - @b. We can't write out the update to @b
* until the new nodes we created are finished writing, so we block @b
* from writing by putting this btree_interior update on the
* @b->write_blocked list with @write_blocked_list:
*/
struct btree *b;
struct list_head write_blocked_list;
/*
* We may be freeing nodes that were dirty, and thus had journal entries
* pinned: we need to transfer the oldest of those pins to the
* btree_update operation, and release it when the new node(s)
* are all persistent and reachable:
*/
struct journal_entry_pin journal;
/* Preallocated nodes we reserve when we start the update: */
struct prealloc_nodes {
struct btree *b[BTREE_UPDATE_NODES_MAX];
unsigned nr;
} prealloc_nodes[2];
/* Nodes being freed: */
struct keylist old_keys;
u64 _old_keys[BTREE_UPDATE_NODES_MAX *
BKEY_BTREE_PTR_U64s_MAX];
/* Nodes being added: */
struct keylist new_keys;
u64 _new_keys[BTREE_UPDATE_NODES_MAX *
BKEY_BTREE_PTR_U64s_MAX];
/* New nodes, that will be made reachable by this update: */
struct btree *new_nodes[BTREE_UPDATE_NODES_MAX];
unsigned nr_new_nodes;
struct btree *old_nodes[BTREE_UPDATE_NODES_MAX];
__le64 old_nodes_seq[BTREE_UPDATE_NODES_MAX];
unsigned nr_old_nodes;
open_bucket_idx_t open_buckets[BTREE_UPDATE_NODES_MAX *
BCH_REPLICAS_MAX];
open_bucket_idx_t nr_open_buckets;
unsigned journal_u64s;
u64 journal_entries[BTREE_UPDATE_JOURNAL_RES];
/* Only here to reduce stack usage on recursive splits: */
struct keylist parent_keys;
/*
* Enough room for btree_split's keys without realloc - btree node
* pointers never have crc/compression info, so we only need to acount
* for the pointers for three keys
*/
u64 inline_keys[BKEY_BTREE_PTR_U64s_MAX * 3];
};
struct btree *__bch2_btree_node_alloc_replacement(struct btree_update *,
struct btree_trans *,
struct btree *,
struct bkey_format);
int bch2_btree_split_leaf(struct btree_trans *, btree_path_idx_t, unsigned);
int bch2_btree_increase_depth(struct btree_trans *, btree_path_idx_t, unsigned);
int __bch2_foreground_maybe_merge(struct btree_trans *, btree_path_idx_t,
unsigned, unsigned, enum btree_node_sibling);
static inline int bch2_foreground_maybe_merge_sibling(struct btree_trans *trans,
btree_path_idx_t path_idx,
unsigned level, unsigned flags,
enum btree_node_sibling sib)
{
struct btree_path *path = trans->paths + path_idx;
struct btree *b;
EBUG_ON(!btree_node_locked(path, level));
b = path->l[level].b;
if (b->sib_u64s[sib] > trans->c->btree_foreground_merge_threshold)
return 0;
return __bch2_foreground_maybe_merge(trans, path_idx, level, flags, sib);
}
static inline int bch2_foreground_maybe_merge(struct btree_trans *trans,
btree_path_idx_t path,
unsigned level,
unsigned flags)
{
return bch2_foreground_maybe_merge_sibling(trans, path, level, flags,
btree_prev_sib) ?:
bch2_foreground_maybe_merge_sibling(trans, path, level, flags,
btree_next_sib);
}
int bch2_btree_node_rewrite(struct btree_trans *, struct btree_iter *,
struct btree *, unsigned);
void bch2_btree_node_rewrite_async(struct bch_fs *, struct btree *);
int bch2_btree_node_update_key(struct btree_trans *, struct btree_iter *,
struct btree *, struct bkey_i *,
unsigned, bool);
int bch2_btree_node_update_key_get_iter(struct btree_trans *, struct btree *,
struct bkey_i *, unsigned, bool);
void bch2_btree_set_root_for_read(struct bch_fs *, struct btree *);
void bch2_btree_root_alloc(struct bch_fs *, enum btree_id);
static inline unsigned btree_update_reserve_required(struct bch_fs *c,
struct btree *b)
{
unsigned depth = btree_node_root(c, b)->c.level + 1;
/*
* Number of nodes we might have to allocate in a worst case btree
* split operation - we split all the way up to the root, then allocate
* a new root, unless we're already at max depth:
*/
if (depth < BTREE_MAX_DEPTH)
return (depth - b->c.level) * 2 + 1;
else
return (depth - b->c.level) * 2 - 1;
}
static inline void btree_node_reset_sib_u64s(struct btree *b)
{
b->sib_u64s[0] = b->nr.live_u64s;
b->sib_u64s[1] = b->nr.live_u64s;
}
static inline void *btree_data_end(struct btree *b)
{
return (void *) b->data + btree_buf_bytes(b);
}
static inline struct bkey_packed *unwritten_whiteouts_start(struct btree *b)
{
return (void *) ((u64 *) btree_data_end(b) - b->whiteout_u64s);
}
static inline struct bkey_packed *unwritten_whiteouts_end(struct btree *b)
{
return btree_data_end(b);
}
static inline void *write_block(struct btree *b)
{
return (void *) b->data + (b->written << 9);
}
static inline bool __btree_addr_written(struct btree *b, void *p)
{
return p < write_block(b);
}
static inline bool bset_written(struct btree *b, struct bset *i)
{
return __btree_addr_written(b, i);
}
static inline bool bkey_written(struct btree *b, struct bkey_packed *k)
{
return __btree_addr_written(b, k);
}
static inline ssize_t __bch2_btree_u64s_remaining(struct btree *b, void *end)
{
ssize_t used = bset_byte_offset(b, end) / sizeof(u64) +
b->whiteout_u64s;
ssize_t total = btree_buf_bytes(b) >> 3;
/* Always leave one extra u64 for bch2_varint_decode: */
used++;
return total - used;
}
static inline size_t bch2_btree_keys_u64s_remaining(struct btree *b)
{
ssize_t remaining = __bch2_btree_u64s_remaining(b,
btree_bkey_last(b, bset_tree_last(b)));
BUG_ON(remaining < 0);
if (bset_written(b, btree_bset_last(b)))
return 0;
return remaining;
}
#define BTREE_WRITE_SET_U64s_BITS 9
static inline unsigned btree_write_set_buffer(struct btree *b)
{
/*
* Could buffer up larger amounts of keys for btrees with larger keys,
* pending benchmarking:
*/
return 8 << BTREE_WRITE_SET_U64s_BITS;
}
static inline struct btree_node_entry *want_new_bset(struct bch_fs *c, struct btree *b)
{
struct bset_tree *t = bset_tree_last(b);
struct btree_node_entry *bne = max(write_block(b),
(void *) btree_bkey_last(b, bset_tree_last(b)));
ssize_t remaining_space =
__bch2_btree_u64s_remaining(b, bne->keys.start);
if (unlikely(bset_written(b, bset(b, t)))) {
if (remaining_space > (ssize_t) (block_bytes(c) >> 3))
return bne;
} else {
if (unlikely(bset_u64s(t) * sizeof(u64) > btree_write_set_buffer(b)) &&
remaining_space > (ssize_t) (btree_write_set_buffer(b) >> 3))
return bne;
}
return NULL;
}
static inline void push_whiteout(struct btree *b, struct bpos pos)
{
struct bkey_packed k;
BUG_ON(bch2_btree_keys_u64s_remaining(b) < BKEY_U64s);
EBUG_ON(btree_node_just_written(b));
if (!bkey_pack_pos(&k, pos, b)) {
struct bkey *u = (void *) &k;
bkey_init(u);
u->p = pos;
}
k.needs_whiteout = true;
b->whiteout_u64s += k.u64s;
bkey_p_copy(unwritten_whiteouts_start(b), &k);
}
/*
* write lock must be held on @b (else the dirty bset that we were going to
* insert into could be written out from under us)
*/
static inline bool bch2_btree_node_insert_fits(struct btree *b, unsigned u64s)
{
if (unlikely(btree_node_need_rewrite(b)))
return false;
return u64s <= bch2_btree_keys_u64s_remaining(b);
}
void bch2_btree_updates_to_text(struct printbuf *, struct bch_fs *);
bool bch2_btree_interior_updates_flush(struct bch_fs *);
void bch2_journal_entry_to_btree_root(struct bch_fs *, struct jset_entry *);
struct jset_entry *bch2_btree_roots_to_journal_entries(struct bch_fs *,
struct jset_entry *, unsigned long);
void bch2_do_pending_node_rewrites(struct bch_fs *);
void bch2_free_pending_node_rewrites(struct bch_fs *);
void bch2_fs_btree_interior_update_exit(struct bch_fs *);
void bch2_fs_btree_interior_update_init_early(struct bch_fs *);
int bch2_fs_btree_interior_update_init(struct bch_fs *);
#endif /* _BCACHEFS_BTREE_UPDATE_INTERIOR_H */