unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
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bcachefs: kill bset_tree->max_key

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Since we now ensure a btree node's max key fits in its packed format,
this isn't needed for the reasons it used to be - and, it was being used
inconsistently.

Also reorder struct btree a bit for performance, and kill some dead
code.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2021-04-03 21:54:14 -04:00 committed by Kent Overstreet
parent 671cc8a51b
commit 3ce8b463e3
2 changed files with 8 additions and 40 deletions
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36
fs/bcachefs/bset.c
View file

@ -686,7 +686,7 @@ static void make_bfloat(struct btree *b, struct bset_tree *t,
if (!bkey_pack_pos(max_key, b->data->max_key, b)) {
k = (void *) max_key;
bkey_init(&k->k);
k->k.p = t->max_key;
k->k.p = b->data->max_key;
}
}
@ -770,8 +770,6 @@ static noinline void __build_ro_aux_tree(struct btree *b, struct bset_tree *t)
while (k != btree_bkey_last(b, t))
prev = k, k = bkey_next(k);
t->max_key = bkey_unpack_pos(b, prev);
if (!bkey_pack_pos(bkey_to_packed(&min_key), b->data->min_key, b)) {
bkey_init(&min_key.k);
min_key.k.p = b->data->min_key;
@ -779,7 +777,7 @@ static noinline void __build_ro_aux_tree(struct btree *b, struct bset_tree *t)
if (!bkey_pack_pos(bkey_to_packed(&max_key), b->data->max_key, b)) {
bkey_init(&max_key.k);
max_key.k.p = t->max_key;
max_key.k.p = b->data->max_key;
}
/* Then we build the tree */
@ -958,8 +956,6 @@ static void ro_aux_tree_fix_invalidated_key(struct btree *b,
min_key.u64s = max_key.u64s = 0;
if (bkey_next(k) == btree_bkey_last(b, t)) {
t->max_key = bkey_unpack_pos(b, k);
for (j = 1; j < t->size; j = j * 2 + 1)
make_bfloat(b, t, j, &min_key, &max_key);
}
@ -1299,16 +1295,6 @@ struct bkey_packed *__bch2_bset_search(struct btree *b,
case BSET_RW_AUX_TREE:
return bset_search_write_set(b, t, search);
case BSET_RO_AUX_TREE:
/*
* Each node in the auxiliary search tree covers a certain range
* of bits, and keys above and below the set it covers might
* differ outside those bits - so we have to special case the
* start and end - handle that here:
*/
if (bpos_cmp(*search, t->max_key) > 0)
return btree_bkey_last(b, t);
return bset_search_tree(b, t, search, lossy_packed_search);
default:
unreachable();
@ -1345,23 +1331,6 @@ struct bkey_packed *bch2_bset_search_linear(struct btree *b,
return m;
}
/*
* Returns the first key greater than or equal to @search
*/
static __always_inline __flatten
struct bkey_packed *bch2_bset_search(struct btree *b,
struct bset_tree *t,
struct bpos *search,
struct bkey_packed *packed_search,
const struct bkey_packed *lossy_packed_search)
{
struct bkey_packed *m = __bch2_bset_search(b, t, search,
lossy_packed_search);
return bch2_bset_search_linear(b, t, search,
packed_search, lossy_packed_search, m);
}
/* Btree node iterator */
static inline void __bch2_btree_node_iter_push(struct btree_node_iter *iter,
@ -1457,6 +1426,7 @@ void bch2_btree_node_iter_init(struct btree_node_iter *iter,
unsigned i;
EBUG_ON(bpos_cmp(*search, b->data->min_key) < 0);
EBUG_ON(bpos_cmp(*search, b->data->max_key) > 0);
bset_aux_tree_verify(b);
memset(iter, 0, sizeof(*iter));

12
fs/bcachefs/btree_types.h
View file

@ -47,8 +47,6 @@ struct bset_tree {
u16 data_offset;
u16 aux_data_offset;
u16 end_offset;
struct bpos max_key;
};
struct btree_write {
@ -98,6 +96,11 @@ struct btree {
u8 byte_order;
u8 unpack_fn_len;
struct btree_write writes[2];
/* Key/pointer for this btree node */
__BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
/*
* XXX: add a delete sequence number, so when bch2_btree_node_relock()
* fails because the lock sequence number has changed - i.e. the
@ -128,11 +131,6 @@ struct btree {
/* lru list */
struct list_head list;
struct btree_write writes[2];
/* Key/pointer for this btree node */
__BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
};
struct btree_cache {