diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c index 51f985154aa1..c8488ebc1d1f 100644 --- a/fs/fuse/dev_uring.c +++ b/fs/fuse/dev_uring.c @@ -204,7 +204,7 @@ void fuse_uring_destruct(struct fuse_chan *fch) return; for (qid = 0; qid < ring->nr_queues; qid++) { - struct fuse_ring_queue *queue = ring->queues[qid]; + struct fuse_ring_queue *queue = READ_ONCE(ring->queues[qid]); struct fuse_ring_ent *ent, *next; if (!queue) @@ -223,7 +223,7 @@ void fuse_uring_destruct(struct fuse_chan *fch) kfree(queue->fpq.processing); kfree(queue); - ring->queues[qid] = NULL; + WRITE_ONCE(ring->queues[qid], NULL); } kfree(ring->queues); @@ -321,9 +321,11 @@ static struct fuse_ring_queue *fuse_uring_create_queue(struct fuse_ring *ring, } /* - * write_once and lock as the caller mostly doesn't take the lock at all + * fch->lock serializes concurrent creators for this qid. + * smp_store_release() are for the lockless readers who must see a + * fully initialized queue after &ring->queues[qid] is set */ - WRITE_ONCE(ring->queues[qid], queue); + smp_store_release(&ring->queues[qid], queue); spin_unlock(&fch->lock); return queue; @@ -434,7 +436,7 @@ static void fuse_uring_log_ent_state(struct fuse_ring *ring) struct fuse_ring_ent *ent; for (qid = 0; qid < ring->nr_queues; qid++) { - struct fuse_ring_queue *queue = ring->queues[qid]; + struct fuse_ring_queue *queue = READ_ONCE(ring->queues[qid]); if (!queue) continue; @@ -967,7 +969,7 @@ static int fuse_uring_commit_fetch(struct io_uring_cmd *cmd, int issue_flags, if (qid >= ring->nr_queues) return -EINVAL; - queue = ring->queues[qid]; + queue = READ_ONCE(ring->queues[qid]); if (!queue) return err; fpq = &queue->fpq; @@ -1035,7 +1037,7 @@ static bool is_ring_ready(struct fuse_ring *ring, int current_qid) if (current_qid == qid) continue; - queue = ring->queues[qid]; + queue = READ_ONCE(ring->queues[qid]); if (!queue) { ready = false; break; @@ -1191,7 +1193,7 @@ static int fuse_uring_register(struct io_uring_cmd *cmd, return -EINVAL; } - queue = ring->queues[qid]; + queue = READ_ONCE(ring->queues[qid]); if (!queue) { queue = fuse_uring_create_queue(ring, qid); if (!queue) @@ -1332,7 +1334,7 @@ static struct fuse_ring_queue *fuse_uring_task_to_queue(struct fuse_ring *ring) ring->nr_queues)) qid = 0; - queue = ring->queues[qid]; + queue = READ_ONCE(ring->queues[qid]); WARN_ONCE(!queue, "Missing queue for qid %d\n", qid); return queue;