gentoo-overlay/sys-kernel/hardened-kernel/files/linux-6.12/0231-bcachefs-Write-lock-bt...

119 lines
4.2 KiB
Diff

From 7b5ddd26bcf1f72e16e121c02533ee6192a3eea0 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Sat, 8 Jun 2024 17:01:31 -0400
Subject: [PATCH 231/233] bcachefs: Write lock btree node in key cache fills
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
this addresses a key cache coherency bug
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Alexander Miroshnichenko <alex@millerson.name>
---
fs/bcachefs/btree_key_cache.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)
diff --git a/fs/bcachefs/btree_key_cache.c b/fs/bcachefs/btree_key_cache.c
index 4eba2871f289..382f99b774b8 100644
--- a/fs/bcachefs/btree_key_cache.c
+++ b/fs/bcachefs/btree_key_cache.c
@@ -197,7 +197,9 @@ bkey_cached_reuse(struct btree_key_cache *c)
return ck;
}
-static int btree_key_cache_create(struct btree_trans *trans, struct btree_path *path,
+static int btree_key_cache_create(struct btree_trans *trans,
+ struct btree_path *path,
+ struct btree_path *ck_path,
struct bkey_s_c k)
{
struct bch_fs *c = trans->c;
@@ -217,7 +219,7 @@ static int btree_key_cache_create(struct btree_trans *trans, struct btree_path *
key_u64s = min(256U, (key_u64s * 3) / 2);
key_u64s = roundup_pow_of_two(key_u64s);
- struct bkey_cached *ck = bkey_cached_alloc(trans, path, key_u64s);
+ struct bkey_cached *ck = bkey_cached_alloc(trans, ck_path, key_u64s);
int ret = PTR_ERR_OR_ZERO(ck);
if (ret)
return ret;
@@ -226,19 +228,19 @@ static int btree_key_cache_create(struct btree_trans *trans, struct btree_path *
ck = bkey_cached_reuse(bc);
if (unlikely(!ck)) {
bch_err(c, "error allocating memory for key cache item, btree %s",
- bch2_btree_id_str(path->btree_id));
+ bch2_btree_id_str(ck_path->btree_id));
return -BCH_ERR_ENOMEM_btree_key_cache_create;
}
}
ck->c.level = 0;
- ck->c.btree_id = path->btree_id;
- ck->key.btree_id = path->btree_id;
- ck->key.pos = path->pos;
+ ck->c.btree_id = ck_path->btree_id;
+ ck->key.btree_id = ck_path->btree_id;
+ ck->key.pos = ck_path->pos;
ck->flags = 1U << BKEY_CACHED_ACCESSED;
if (unlikely(key_u64s > ck->u64s)) {
- mark_btree_node_locked_noreset(path, 0, BTREE_NODE_UNLOCKED);
+ mark_btree_node_locked_noreset(ck_path, 0, BTREE_NODE_UNLOCKED);
struct bkey_i *new_k = allocate_dropping_locks(trans, ret,
kmalloc(key_u64s * sizeof(u64), _gfp));
@@ -258,22 +260,29 @@ static int btree_key_cache_create(struct btree_trans *trans, struct btree_path *
bkey_reassemble(ck->k, k);
+ ret = bch2_btree_node_lock_write(trans, path, &path_l(path)->b->c);
+ if (unlikely(ret))
+ goto err;
+
ret = rhashtable_lookup_insert_fast(&bc->table, &ck->hash, bch2_btree_key_cache_params);
+
+ bch2_btree_node_unlock_write(trans, path, path_l(path)->b);
+
if (unlikely(ret)) /* raced with another fill? */
goto err;
atomic_long_inc(&bc->nr_keys);
six_unlock_write(&ck->c.lock);
- enum six_lock_type lock_want = __btree_lock_want(path, 0);
+ enum six_lock_type lock_want = __btree_lock_want(ck_path, 0);
if (lock_want == SIX_LOCK_read)
six_lock_downgrade(&ck->c.lock);
- btree_path_cached_set(trans, path, ck, (enum btree_node_locked_type) lock_want);
- path->uptodate = BTREE_ITER_UPTODATE;
+ btree_path_cached_set(trans, ck_path, ck, (enum btree_node_locked_type) lock_want);
+ ck_path->uptodate = BTREE_ITER_UPTODATE;
return 0;
err:
bkey_cached_free(bc, ck);
- mark_btree_node_locked_noreset(path, 0, BTREE_NODE_UNLOCKED);
+ mark_btree_node_locked_noreset(ck_path, 0, BTREE_NODE_UNLOCKED);
return ret;
}
@@ -293,6 +302,7 @@ static noinline int btree_key_cache_fill(struct btree_trans *trans,
int ret;
bch2_trans_iter_init(trans, &iter, ck_path->btree_id, ck_path->pos,
+ BTREE_ITER_intent|
BTREE_ITER_key_cache_fill|
BTREE_ITER_cached_nofill);
iter.flags &= ~BTREE_ITER_with_journal;
@@ -306,7 +316,7 @@ static noinline int btree_key_cache_fill(struct btree_trans *trans,
if (unlikely(ret))
goto out;
- ret = btree_key_cache_create(trans, ck_path, k);
+ ret = btree_key_cache_create(trans, btree_iter_path(trans, &iter), ck_path, k);
if (ret)
goto err;
--
2.45.2