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bcachefs: Change where merging of interior btree nodes is trigger from

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Previously, we were doing btree node merging from
bch2_btree_insert_node() - but this is called from the split path, when
we're in the middle of creating new nodes and deleting new nodes and the
iterators are in a weird state.

Also, this means we're starting a new btree_update while in the middle
of an existing one, and that's asking for deadlocks.

Much simpler and saner to trigger btree node merging _after_ the whole
btree node split path is finished.

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 2021-03-31 15:39:16 -04:00 committed by Kent Overstreet
parent e264b2f62a
commit 1259cc31b2
1 changed files with 7 additions and 9 deletions
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16
fs/bcachefs/btree_update_interior.c
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@ -1505,14 +1505,6 @@ void bch2_btree_insert_node(struct btree_update *as, struct btree *b,
bch2_btree_node_unlock_write(b, iter);
btree_node_interior_verify(c, b);
/*
* when called from the btree_split path the new nodes aren't added to
* the btree iterator yet, so the merge path's unlock/wait/relock dance
* won't work:
*/
bch2_foreground_maybe_merge(c, iter, b->c.level,
flags|BTREE_INSERT_NOUNLOCK);
return;
split:
btree_split(as, b, iter, keys, flags);
@ -1523,6 +1515,8 @@ int bch2_btree_split_leaf(struct bch_fs *c, struct btree_iter *iter,
{
struct btree *b = iter_l(iter)->b;
struct btree_update *as;
unsigned l;
int ret = 0;
as = bch2_btree_update_start(iter, iter->level,
btree_update_reserve_required(c, b), flags);
@ -1531,7 +1525,11 @@ int bch2_btree_split_leaf(struct bch_fs *c, struct btree_iter *iter,
btree_split(as, b, iter, NULL, flags);
bch2_btree_update_done(as);
return 0;
for (l = iter->level + 1; btree_iter_node(iter, l) && !ret; l++)
bch2_foreground_maybe_merge(c, iter, l, flags);
return ret;
}
void __bch2_foreground_maybe_merge(struct bch_fs *c,