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bcachefs: Improve bch2_dev_freespace_init()

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This makes bch2_dev_freespace_init() much faster: instead of processing
every bucket on the device one at a time, we handle ranges of missing
keys all at once: the freespace btree is an extents style btree, so we
only have to insert one freespace key for every range of missing keys
in the alloc btree.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2022-11-26 04:37:11 -05:00
parent 7c057d3509
commit cc65f56599
1 changed files with 93 additions and 18 deletions
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111
fs/bcachefs/alloc_background.c
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@ -1317,35 +1317,110 @@ void bch2_do_invalidates(struct bch_fs *c)
bch2_write_ref_put(c, BCH_WRITE_REF_invalidate);
}
static int bucket_freespace_init(struct btree_trans *trans, struct btree_iter *iter,
struct bkey_s_c k, struct bch_dev *ca)
{
struct bch_alloc_v4 a_convert;
const struct bch_alloc_v4 *a;
if (iter->pos.offset >= ca->mi.nbuckets)
return 1;
a = bch2_alloc_to_v4(k, &a_convert);
return bch2_bucket_do_index(trans, k, a, true);
}
static int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca)
{
struct btree_trans trans;
struct btree_iter iter;
struct bkey_s_c k;
struct bpos end = POS(ca->dev_idx, ca->mi.nbuckets);
struct bch_member *m;
int ret;
bch2_trans_init(&trans, c, 0, 0);
ret = for_each_btree_key_commit(&trans, iter, BTREE_ID_alloc,
POS(ca->dev_idx, ca->mi.first_bucket),
BTREE_ITER_SLOTS|BTREE_ITER_PREFETCH, k,
NULL, NULL, BTREE_INSERT_LAZY_RW,
bucket_freespace_init(&trans, &iter, k, ca));
bch2_trans_iter_init(&trans, &iter, BTREE_ID_alloc,
POS(ca->dev_idx, ca->mi.first_bucket),
BTREE_ITER_PREFETCH);
/*
* Scan the alloc btree for every bucket on @ca, and add buckets to the
* freespace/need_discard/need_gc_gens btrees as needed:
*/
while (1) {
bch2_trans_begin(&trans);
ret = 0;
if (bkey_ge(iter.pos, end))
break;
k = bch2_btree_iter_peek_slot(&iter);
ret = bkey_err(k);
if (ret)
goto bkey_err;
if (k.k->type) {
/*
* We process live keys in the alloc btree one at a
* time:
*/
struct bch_alloc_v4 a_convert;
const struct bch_alloc_v4 *a = bch2_alloc_to_v4(k, &a_convert);
ret = bch2_bucket_do_index(&trans, k, a, true) ?:
bch2_trans_commit(&trans, NULL, NULL,
BTREE_INSERT_LAZY_RW|
BTREE_INSERT_NOFAIL);
if (ret)
goto bkey_err;
bch2_btree_iter_advance(&iter);
} else {
/*
* When there's a hole, process a whole range of keys
* all at once:
*
* This is similar to how extent btree iterators in
* slots mode will synthesize a whole range - a
* KEY_TYPE_deleted extent.
*
* But alloc keys aren't extents (they have zero size),
* so we're open coding it here:
*/
struct btree_iter iter2;
struct bkey_i *freespace;
struct bpos next;
bch2_trans_copy_iter(&iter2, &iter);
k = bch2_btree_iter_peek_upto(&iter2,
bkey_min(bkey_min(end,
iter.path->l[0].b->key.k.p),
POS(iter.pos.inode, iter.pos.offset + U32_MAX - 1)));
next = iter2.pos;
ret = bkey_err(k);
bch2_trans_iter_exit(&trans, &iter2);
BUG_ON(next.offset >= iter.pos.offset + U32_MAX);
if (ret)
goto bkey_err;
freespace = bch2_trans_kmalloc(&trans, sizeof(*freespace));
ret = PTR_ERR_OR_ZERO(freespace);
if (ret)
goto bkey_err;
bkey_init(&freespace->k);
freespace->k.type = KEY_TYPE_set;
freespace->k.p = iter.pos;
bch2_key_resize(&freespace->k, next.offset - iter.pos.offset);
ret = __bch2_btree_insert(&trans, BTREE_ID_freespace, freespace) ?:
bch2_trans_commit(&trans, NULL, NULL,
BTREE_INSERT_LAZY_RW|
BTREE_INSERT_NOFAIL);
if (ret)
goto bkey_err;
bch2_btree_iter_set_pos(&iter, next);
}
bkey_err:
if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
continue;
if (ret)
break;
}
bch2_trans_iter_exit(&trans, &iter);
bch2_trans_exit(&trans);
if (ret < 0) {