[PATCH] bcachefs: Use alloc_percpu_gfp to avoid deadlock

[Alan Huang <mmpgouride@gmail.com>]

The cycle:

CPU0:			CPU1:
bc->lock		pcpu_alloc_mutex
pcpu_alloc_mutex	bc->lock

Reported-by: syzbot+fe63f377148a6371a9db@syzkaller.appspotmail.com
Tested-by: syzbot+fe63f377148a6371a9db@syzkaller.appspotmail.com
Signed-off-by: Alan Huang <mmpgouride@gmail.com>
---
 fs/bcachefs/six.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/bcachefs/six.c b/fs/bcachefs/six.c
index 7e7c66a1e1a6..ccdc6d496910 100644
--- a/fs/bcachefs/six.c
+++ b/fs/bcachefs/six.c
@@ -873,7 +873,7 @@ void __six_lock_init(struct six_lock *lock, const char *name,
 		 * failure if they wish by checking lock->readers, but generally
 		 * will not want to treat it as an error.
 		 */
-		lock->readers = alloc_percpu(unsigned);
+		lock->readers = alloc_percpu_gfp(unsigned, GFP_NOWAIT|__GFP_NOWARN);
 	}
 #endif
 }
-- 
2.47.0