bcachefs: Fix large key cache keys

Previously, we'd go into an infinite loop when attempting to cache a
bkey in the key cache larger than 128 u64s - since we were only using a
u8 for the size field, it'd get rounded up to 256 then truncated to 0.
Oops.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This commit is contained in:
Kent Overstreet 2022-03-17 21:35:51 -04:00 committed by Kent Overstreet
parent f8494d2535
commit 3a306f3c2c
3 changed files with 41 additions and 6 deletions

View File

@ -323,7 +323,7 @@ struct bkey_cached {
struct btree_bkey_cached_common c;
unsigned long flags;
u8 u64s;
u16 u64s;
bool valid;
u32 btree_trans_barrier_seq;
struct bkey_cached_key key;

View File

@ -351,7 +351,7 @@ btree_key_can_insert_cached(struct btree_trans *trans,
{
struct bch_fs *c = trans->c;
struct bkey_cached *ck = (void *) path->l[0].b;
unsigned new_u64s;
unsigned old_u64s = ck->u64s, new_u64s;
struct bkey_i *new_k;
EBUG_ON(path->level);
@ -385,7 +385,8 @@ btree_key_can_insert_cached(struct btree_trans *trans,
* transaction restart:
*/
trace_trans_restart_key_cache_key_realloced(trans->fn, _RET_IP_,
path->btree_id, &path->pos);
path->btree_id, &path->pos,
old_u64s, new_u64s);
/*
* Not using btree_trans_restart() because we can't unlock here, we have
* write locks held:

View File

@ -918,12 +918,46 @@ TRACE_EVENT(trans_restart_mem_realloced,
__entry->bytes)
);
DEFINE_EVENT(transaction_restart_iter, trans_restart_key_cache_key_realloced,
TRACE_EVENT(trans_restart_key_cache_key_realloced,
TP_PROTO(const char *trans_fn,
unsigned long caller_ip,
enum btree_id btree_id,
struct bpos *pos),
TP_ARGS(trans_fn, caller_ip, btree_id, pos)
struct bpos *pos,
unsigned old_u64s,
unsigned new_u64s),
TP_ARGS(trans_fn, caller_ip, btree_id, pos, old_u64s, new_u64s),
TP_STRUCT__entry(
__array(char, trans_fn, 24 )
__field(unsigned long, caller_ip )
__field(enum btree_id, btree_id )
__field(u64, inode )
__field(u64, offset )
__field(u32, snapshot )
__field(u32, old_u64s )
__field(u32, new_u64s )
),
TP_fast_assign(
strncpy(__entry->trans_fn, trans_fn, sizeof(__entry->trans_fn));
__entry->caller_ip = caller_ip;
__entry->btree_id = btree_id;
__entry->inode = pos->inode;
__entry->offset = pos->offset;
__entry->snapshot = pos->snapshot;
__entry->old_u64s = old_u64s;
__entry->new_u64s = new_u64s;
),
TP_printk("%s %pS btree %s pos %llu:%llu:%u old_u64s %u new_u64s %u",
__entry->trans_fn,
(void *) __entry->caller_ip,
bch2_btree_ids[__entry->btree_id],
__entry->inode,
__entry->offset,
__entry->snapshot,
__entry->old_u64s,
__entry->new_u64s)
);
#endif /* _TRACE_BCACHEFS_H */