From 93b8cc60c37b9d17732b7a297e5dca29b50a990d Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 28 Sep 2023 20:43:25 +0800 Subject: io_uring: cancelable uring_cmd uring_cmd may never complete, such as ublk, in which uring cmd isn't completed until one new block request is coming from ublk block device. Add cancelable uring_cmd to provide mechanism to driver for cancelling pending commands in its own way. Add API of io_uring_cmd_mark_cancelable() for driver to mark one command as cancelable, then io_uring will cancel this command in io_uring_cancel_generic(). ->uring_cmd() callback is reused for canceling command in driver's way, then driver gets notified with the cancelling from io_uring. Add API of io_uring_cmd_get_task() to help driver cancel handler deal with the canceling. Reviewed-by: Gabriel Krisman Bertazi Suggested-by: Jens Axboe Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- io_uring/io_uring.c | 33 +++++++++++++++++++++++++++++++++ io_uring/uring_cmd.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 80 insertions(+) (limited to 'io_uring') diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index cb6bd9907045..08c9ea46bb95 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -352,6 +352,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) INIT_HLIST_HEAD(&ctx->waitid_list); INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func); INIT_WQ_LIST(&ctx->submit_state.compl_reqs); + INIT_HLIST_HEAD(&ctx->cancelable_uring_cmd); return ctx; err: kfree(ctx->cancel_table.hbs); @@ -3258,6 +3259,37 @@ static __cold bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx) return ret; } +static bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx, + struct task_struct *task, bool cancel_all) +{ + struct hlist_node *tmp; + struct io_kiocb *req; + bool ret = false; + + lockdep_assert_held(&ctx->uring_lock); + + hlist_for_each_entry_safe(req, tmp, &ctx->cancelable_uring_cmd, + hash_node) { + struct io_uring_cmd *cmd = io_kiocb_to_cmd(req, + struct io_uring_cmd); + struct file *file = req->file; + + if (!cancel_all && req->task != task) + continue; + + if (cmd->flags & IORING_URING_CMD_CANCELABLE) { + /* ->sqe isn't available if no async data */ + if (!req_has_async_data(req)) + cmd->sqe = NULL; + file->f_op->uring_cmd(cmd, IO_URING_F_CANCEL); + ret = true; + } + } + io_submit_flush_completions(ctx); + + return ret; +} + static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, struct task_struct *task, bool cancel_all) @@ -3306,6 +3338,7 @@ static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, mutex_lock(&ctx->uring_lock); ret |= io_poll_remove_all(ctx, task, cancel_all); ret |= io_waitid_remove_all(ctx, task, cancel_all); + ret |= io_uring_try_cancel_uring_cmd(ctx, task, cancel_all); mutex_unlock(&ctx->uring_lock); ret |= io_kill_timeouts(ctx, task, cancel_all); if (task) diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index a0b0ec5473bf..00a5e5621a28 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -13,6 +13,51 @@ #include "rsrc.h" #include "uring_cmd.h" +static void io_uring_cmd_del_cancelable(struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(cmd); + struct io_ring_ctx *ctx = req->ctx; + + if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) + return; + + cmd->flags &= ~IORING_URING_CMD_CANCELABLE; + io_ring_submit_lock(ctx, issue_flags); + hlist_del(&req->hash_node); + io_ring_submit_unlock(ctx, issue_flags); +} + +/* + * Mark this command as concelable, then io_uring_try_cancel_uring_cmd() + * will try to cancel this issued command by sending ->uring_cmd() with + * issue_flags of IO_URING_F_CANCEL. + * + * The command is guaranteed to not be done when calling ->uring_cmd() + * with IO_URING_F_CANCEL, but it is driver's responsibility to deal + * with race between io_uring canceling and normal completion. + */ +void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + struct io_kiocb *req = cmd_to_io_kiocb(cmd); + struct io_ring_ctx *ctx = req->ctx; + + if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) { + cmd->flags |= IORING_URING_CMD_CANCELABLE; + io_ring_submit_lock(ctx, issue_flags); + hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd); + io_ring_submit_unlock(ctx, issue_flags); + } +} +EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable); + +struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd) +{ + return cmd_to_io_kiocb(cmd)->task; +} +EXPORT_SYMBOL_GPL(io_uring_cmd_get_task); + static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts) { struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); @@ -56,6 +101,8 @@ void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2, { struct io_kiocb *req = cmd_to_io_kiocb(ioucmd); + io_uring_cmd_del_cancelable(ioucmd, issue_flags); + if (ret < 0) req_set_fail(req); -- cgit v1.2.3