[PATCH for-next v3 2/4] io_uring: add iopoll infrastructure for io_uring_cmd
From: Kanchan Joshi <hidden>
Date: 2022-08-23 18:13:11
Also in:
io-uring, linux-nvme
Subsystem:
io_uring, the rest · Maintainers:
Jens Axboe, Linus Torvalds
Put this up in the same way as iopoll is done for regular read/write IO. Make place for storing a cookie into struct io_uring_cmd on submission. Perform the completion using the ->uring_cmd_iopoll handler. Signed-off-by: Kanchan Joshi <redacted> Signed-off-by: Pankaj Raghav <redacted> --- include/linux/io_uring.h | 8 ++++++-- io_uring/io_uring.c | 6 ++++++ io_uring/opdef.c | 1 + io_uring/rw.c | 8 +++++++- io_uring/uring_cmd.c | 11 +++++++++-- 5 files changed, 29 insertions(+), 5 deletions(-)
diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index 4a2f6cc5a492..58676c0a398f 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h@@ -20,8 +20,12 @@ enum io_uring_cmd_flags { struct io_uring_cmd { struct file *file; const void *cmd; - /* callback to defer completions to task context */ - void (*task_work_cb)(struct io_uring_cmd *cmd); + union { + /* callback to defer completions to task context */ + void (*task_work_cb)(struct io_uring_cmd *cmd); + /* used for polled completion */ + void *cookie; + }; u32 cmd_op; u32 pad; u8 pdu[32]; /* available inline for free use */
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index ebfdb2212ec2..04abcc67648e 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c@@ -1296,6 +1296,12 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min) wq_list_empty(&ctx->iopoll_list)) break; } + + if (task_work_pending(current)) { + mutex_unlock(&ctx->uring_lock); + io_run_task_work(); + mutex_lock(&ctx->uring_lock); + } ret = io_do_iopoll(ctx, !min); if (ret < 0) break;
diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index 72dd2b2d8a9d..9a0df19306fe 100644
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c@@ -466,6 +466,7 @@ const struct io_op_def io_op_defs[] = { .needs_file = 1, .plug = 1, .name = "URING_CMD", + .iopoll = 1, .async_size = uring_cmd_pdu_size(1), .prep = io_uring_cmd_prep, .issue = io_uring_cmd,
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 1babd77da79c..9698a789b3d5 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c@@ -1005,7 +1005,13 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) if (READ_ONCE(req->iopoll_completed)) break; - ret = rw->kiocb.ki_filp->f_op->iopoll(&rw->kiocb, &iob, poll_flags); + if (req->opcode == IORING_OP_URING_CMD) { + struct io_uring_cmd *ioucmd = (struct io_uring_cmd *)rw; + + ret = req->file->f_op->uring_cmd_iopoll(ioucmd); + } else + ret = rw->kiocb.ki_filp->f_op->iopoll(&rw->kiocb, &iob, + poll_flags); if (unlikely(ret < 0)) return ret; else if (ret)
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 8e0cc2d9205e..b0e7feeed365 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c@@ -49,7 +49,11 @@ void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2) io_req_set_res(req, ret, 0); if (req->ctx->flags & IORING_SETUP_CQE32) io_req_set_cqe32_extra(req, res2, 0); - __io_req_complete(req, 0); + if (req->ctx->flags & IORING_SETUP_IOPOLL) + /* order with io_iopoll_req_issued() checking ->iopoll_complete */ + smp_store_release(&req->iopoll_completed, 1); + else + __io_req_complete(req, 0); } EXPORT_SYMBOL_GPL(io_uring_cmd_done);
@@ -92,8 +96,11 @@ int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags) issue_flags |= IO_URING_F_SQE128; if (ctx->flags & IORING_SETUP_CQE32) issue_flags |= IO_URING_F_CQE32; - if (ctx->flags & IORING_SETUP_IOPOLL) + if (ctx->flags & IORING_SETUP_IOPOLL) { issue_flags |= IO_URING_F_IOPOLL; + req->iopoll_completed = 0; + WRITE_ONCE(ioucmd->cookie, NULL); + } if (req_has_async_data(req)) ioucmd->cmd = req->async_data;
--
2.25.1