Re: [syzbot] [bcachefs?] WARNING in bch2_fs_read_write_early

[Edward Adam Davis]

please test no write lock in bch2_fs_read_write_early

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 2ccbdf43d5e7

diff --git a/fs/bcachefs/snapshot.c b/fs/bcachefs/snapshot.c
index 51918acfd726..b27a4327274d 100644
--- a/fs/bcachefs/snapshot.c
+++ b/fs/bcachefs/snapshot.c
@@ -1566,7 +1566,9 @@ int bch2_delete_dead_snapshots(struct bch_fs *c)
 		return 0;
 
 	if (!test_bit(BCH_FS_started, &c->flags)) {
+		down_write(&c->state_lock);
 		ret = bch2_fs_read_write_early(c);
+		up_write(&c->state_lock);
 		bch_err_msg(c, ret, "deleting dead snapshots: error going rw");
 		if (ret)
 			return ret;
diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h
index bbe9000260d0..cbccc0bbee76 100644
--- a/kernel/locking/lockdep_internals.h
+++ b/kernel/locking/lockdep_internals.h
@@ -99,9 +99,9 @@ static const unsigned long LOCKF_USED_IN_IRQ_READ =
 #define MAX_STACK_TRACE_ENTRIES	262144UL
 #define STACK_TRACE_HASH_SIZE	8192
 #else
-#define MAX_LOCKDEP_ENTRIES	(1UL << CONFIG_LOCKDEP_BITS)
+#define MAX_LOCKDEP_ENTRIES	(1UL << 19)
 
-#define MAX_LOCKDEP_CHAINS_BITS	CONFIG_LOCKDEP_CHAINS_BITS
+#define MAX_LOCKDEP_CHAINS_BITS	20
 
 /*
  * Stack-trace: tightly packed array of stack backtrace