On 22.10.2024 09:43, Hongbo Li wrote:
On 2024/10/22 0:48, Manas via B4 Relay wrote:
From: Manas <[email protected]>
This reverts commit 60f2b1bcf519416dbffee219132aa949d0c39d0e.
This syzbot bug[1] is triggered due to the BUG_ON assertions added in
__bch2_dev_btree_bitmap_mark. During runtime, m->btree_bitmap_shift is
63 '?'. This triggers both the assertions.
Reverting the commit does not reproduce the said bug.
[1] https://syzkaller.appspot.com/bug?extid=e8eff054face85d7ea41
Signed-off-by: Manas <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=e8eff054face85d7ea41
---
This syzbot bug[1] is triggered due to the BUG_ON assertions added in
__bch2_dev_btree_bitmap_mark. During runtime, m->btree_bitmap_shift is
63 '?'. This triggers both the assertions.
I am unfamiliar with the codebase, and there wasn't a lore discussion
about the assertions in the commit, so I am unsure about the relevance
of these assertions.
Reverting the commit does not reproduce the said bug.
[1] https://syzkaller.appspot.com/bug?extid=e8eff054face85d7ea41
---
fs/bcachefs/sb-members.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/fs/bcachefs/sb-members.c b/fs/bcachefs/sb-members.c
index
fb08dd680dacf82bca414f424024e4a00bf432de..9790fd47338c46d2af30547e1f41a1e578b71aa4
100644
--- a/fs/bcachefs/sb-members.c
+++ b/fs/bcachefs/sb-members.c
@@ -450,9 +450,6 @@ static void __bch2_dev_btree_bitmap_mark(struct
bch_sb_field_members_v2 *mi, uns
m->btree_bitmap_shift += resize;
}
- BUG_ON(m->btree_bitmap_shift > 57);
- BUG_ON(end > 64ULL << m->btree_bitmap_shift);
-
May be this is not good way by just removing the BUG_ON. In my humble
opinion, the former code have checked m->btree_bitmap_shift in
bch2_dev_btree_bitmap_marked_sectors. May be add the similar condition
in this helper will be better.
Hi Hongbo, thanks for reviewing this. I was unsure about the fix so I decided to
initiate the conversation by reverting. Yes, that makes sense. I am sending a
fresh patch adding that condition.
--
Manas
