diff options
Diffstat (limited to 'drivers/block/ublk_drv.c')
| -rw-r--r-- | drivers/block/ublk_drv.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 2b7d1db5c4a7..6a4a94b4cdf4 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -555,7 +555,7 @@ static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu( return (struct ublk_uring_cmd_pdu *)&ioucmd->pdu; } -static bool ubq_daemon_is_dying(struct ublk_queue *ubq) +static inline bool ubq_daemon_is_dying(struct ublk_queue *ubq) { return ubq->ubq_daemon->flags & PF_EXITING; } @@ -605,8 +605,9 @@ static void ublk_complete_rq(struct request *req) } /* - * __ublk_fail_req() may be called from abort context or ->ubq_daemon - * context during exiting, so lock is required. + * Since __ublk_rq_task_work always fails requests immediately during + * exiting, __ublk_fail_req() is only called from abort context during + * exiting. So lock is unnecessary. * * Also aborting may not be started yet, keep in mind that one failed * request may be issued by block layer again. @@ -644,8 +645,7 @@ static inline void __ublk_rq_task_work(struct request *req) struct ublk_device *ub = ubq->dev; int tag = req->tag; struct ublk_io *io = &ubq->ios[tag]; - bool task_exiting = current != ubq->ubq_daemon || - (current->flags & PF_EXITING); + bool task_exiting = current != ubq->ubq_daemon || ubq_daemon_is_dying(ubq); unsigned int mapped_bytes; pr_devel("%s: complete: op %d, qid %d tag %d io_flags %x addr %llx\n", @@ -680,6 +680,11 @@ static inline void __ublk_rq_task_work(struct request *req) * do the copy work. */ io->flags &= ~UBLK_IO_FLAG_NEED_GET_DATA; + /* update iod->addr because ublksrv may have passed a new io buffer */ + ublk_get_iod(ubq, req->tag)->addr = io->addr; + pr_devel("%s: update iod->addr: op %d, qid %d tag %d io_flags %x addr %llx\n", + __func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags, + ublk_get_iod(ubq, req->tag)->addr); } mapped_bytes = ublk_map_io(ubq, req, io); @@ -751,9 +756,25 @@ static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, if (task_work_add(ubq->ubq_daemon, &data->work, notify_mode)) goto fail; } else { - struct io_uring_cmd *cmd = ubq->ios[rq->tag].cmd; + struct ublk_io *io = &ubq->ios[rq->tag]; + struct io_uring_cmd *cmd = io->cmd; struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); + /* + * If the check pass, we know that this is a re-issued request aborted + * previously in monitor_work because the ubq_daemon(cmd's task) is + * PF_EXITING. We cannot call io_uring_cmd_complete_in_task() anymore + * because this ioucmd's io_uring context may be freed now if no inflight + * ioucmd exists. Otherwise we may cause null-deref in ctx->fallback_work. + * + * Note: monitor_work sets UBLK_IO_FLAG_ABORTED and ends this request(releasing + * the tag). Then the request is re-started(allocating the tag) and we are here. + * Since releasing/allocating a tag implies smp_mb(), finding UBLK_IO_FLAG_ABORTED + * guarantees that here is a re-issued request aborted previously. + */ + if ((io->flags & UBLK_IO_FLAG_ABORTED)) + goto fail; + pdu->req = rq; io_uring_cmd_complete_in_task(cmd, ublk_rq_task_work_cb); } |