From 36a005b9c66eade68f4235e612d733510a8d52ff Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 18 Mar 2024 22:00:26 +0000 Subject: io_uring/cmd: document some uring_cmd related helpers Add comments warning users that they're only allowed to pass issue_flags that were given from io_uring. Signed-off-by: Pavel Begunkov Reviewed-by: Ming Lei Tested-by: Ming Lei Link: https://lore.kernel.org/r/82ff8a45f2c3eb5f3a04a33f0692e5e4a1320455.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- include/linux/io_uring/cmd.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/linux/io_uring/cmd.h') diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h index e453a997c060..01b95505538a 100644 --- a/include/linux/io_uring/cmd.h +++ b/include/linux/io_uring/cmd.h @@ -26,12 +26,25 @@ static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe) #if defined(CONFIG_IO_URING) int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw, struct iov_iter *iter, void *ioucmd); + +/* + * Completes the request, i.e. posts an io_uring CQE and deallocates @ioucmd + * and the corresponding io_uring request. + * + * Note: the caller should never hard code @issue_flags and is only allowed + * to pass the mask provided by the core io_uring code. + */ void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2, unsigned issue_flags); + void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd, void (*task_work_cb)(struct io_uring_cmd *, unsigned), unsigned flags); +/* + * Note: the caller should never hard code @issue_flags and only use the + * mask provided by the core io_uring code. + */ void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, unsigned int issue_flags); -- cgit v1.2.3 From 1afdb76038e27a3a4dd4cf522f6457868051db84 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 19 Mar 2024 17:10:50 -0600 Subject: nvme/io_uring: use helper for polled completions NVMe is making up issue_flags, which is a no-no in general, and to make matters worse, they are completely the wrong ones. For a pure polled request, which it does check for, we're already inside the ctx->uring_lock when the completions are run off io_do_iopoll(). Hence the correct flag would be '0' rather than IO_URING_F_UNLOCKED. Reviewed-by: Pavel Begunkov Signed-off-by: Jens Axboe --- drivers/nvme/host/ioctl.c | 15 +++++++++++---- include/linux/io_uring/cmd.h | 11 +++++++++++ 2 files changed, 22 insertions(+), 4 deletions(-) (limited to 'include/linux/io_uring/cmd.h') diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c index 3dfd5ae99ae0..499a8bb7cac7 100644 --- a/drivers/nvme/host/ioctl.c +++ b/drivers/nvme/host/ioctl.c @@ -423,13 +423,20 @@ static enum rq_end_io_ret nvme_uring_cmd_end_io(struct request *req, pdu->result = le64_to_cpu(nvme_req(req)->result.u64); /* - * For iopoll, complete it directly. + * For iopoll, complete it directly. Note that using the uring_cmd + * helper for this is safe only because we check blk_rq_is_poll(). + * As that returns false if we're NOT on a polled queue, then it's + * safe to use the polled completion helper. + * * Otherwise, move the completion to task work. */ - if (blk_rq_is_poll(req)) - nvme_uring_task_cb(ioucmd, IO_URING_F_UNLOCKED); - else + if (blk_rq_is_poll(req)) { + if (pdu->bio) + blk_rq_unmap_user(pdu->bio); + io_uring_cmd_iopoll_done(ioucmd, pdu->result, pdu->status); + } else { io_uring_cmd_do_in_task_lazy(ioucmd, nvme_uring_task_cb); + } return RQ_END_IO_FREE; } diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h index 01b95505538a..447fbfd32215 100644 --- a/include/linux/io_uring/cmd.h +++ b/include/linux/io_uring/cmd.h @@ -69,6 +69,17 @@ static inline void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, } #endif +/* + * Polled completions must ensure they are coming from a poll queue, and + * hence are completed inside the usual poll handling loops. + */ +static inline void io_uring_cmd_iopoll_done(struct io_uring_cmd *ioucmd, + ssize_t ret, ssize_t res2) +{ + lockdep_assert(in_task()); + io_uring_cmd_done(ioucmd, ret, res2, 0); +} + /* users must follow the IOU_F_TWQ_LAZY_WAKE semantics */ static inline void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd, void (*task_work_cb)(struct io_uring_cmd *, unsigned)) -- cgit v1.2.3