From f6edbabb8359798c541b0776616c5eab3a840d3d Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Fri, 6 Nov 2020 13:00:26 +0000 Subject: io_uring: always batch cancel in *cancel_files() Instead of iterating over each request and cancelling it individually in io_uring_cancel_files(), try to cancel all matching requests and use ->inflight_list only to check if there anything left. In many cases it should be faster, and we can reuse a lot of code from task cancellation. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 135 +++++++++------------------------------------------------- 1 file changed, 21 insertions(+), 114 deletions(-) (limited to 'fs/io_uring.c') diff --git a/fs/io_uring.c b/fs/io_uring.c index a51dcd33a1b8..733ba91e0205 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1577,15 +1577,6 @@ static void io_kill_timeout(struct io_kiocb *req) } } -static bool io_task_match(struct io_kiocb *req, struct task_struct *tsk) -{ - struct io_ring_ctx *ctx = req->ctx; - - if (!tsk || req->task == tsk) - return true; - return (ctx->flags & IORING_SETUP_SQPOLL); -} - /* * Returns true if we found and killed one or more timeouts */ @@ -8667,108 +8658,31 @@ static int io_uring_release(struct inode *inode, struct file *file) return 0; } -/* - * Returns true if 'preq' is the link parent of 'req' - */ -static bool io_match_link(struct io_kiocb *preq, struct io_kiocb *req) -{ - struct io_kiocb *link; - - io_for_each_link(link, preq->link) { - if (link == req) - return true; - } - return false; -} - -/* - * We're looking to cancel 'req' because it's holding on to our files, but - * 'req' could be a link to another request. See if it is, and cancel that - * parent request if so. - */ -static bool io_poll_remove_link(struct io_ring_ctx *ctx, struct io_kiocb *req) -{ - struct hlist_node *tmp; - struct io_kiocb *preq; - bool found = false; - int i; - - spin_lock_irq(&ctx->completion_lock); - for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { - struct hlist_head *list; - - list = &ctx->cancel_hash[i]; - hlist_for_each_entry_safe(preq, tmp, list, hash_node) { - found = io_match_link(preq, req); - if (found) { - io_poll_remove_one(preq); - break; - } - } - } - spin_unlock_irq(&ctx->completion_lock); - return found; -} - -static bool io_timeout_remove_link(struct io_ring_ctx *ctx, - struct io_kiocb *req) -{ - struct io_kiocb *preq; - bool found = false; - - spin_lock_irq(&ctx->completion_lock); - list_for_each_entry(preq, &ctx->timeout_list, timeout.list) { - found = io_match_link(preq, req); - if (found) { - __io_timeout_cancel(preq); - break; - } - } - spin_unlock_irq(&ctx->completion_lock); - return found; -} +struct io_task_cancel { + struct task_struct *task; + struct files_struct *files; +}; -static bool io_cancel_link_cb(struct io_wq_work *work, void *data) +static bool io_cancel_task_cb(struct io_wq_work *work, void *data) { struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct io_task_cancel *cancel = data; bool ret; - if (req->flags & REQ_F_LINK_TIMEOUT) { + if (cancel->files && (req->flags & REQ_F_LINK_TIMEOUT)) { unsigned long flags; struct io_ring_ctx *ctx = req->ctx; /* protect against races with linked timeouts */ spin_lock_irqsave(&ctx->completion_lock, flags); - ret = io_match_link(req, data); + ret = io_match_task(req, cancel->task, cancel->files); spin_unlock_irqrestore(&ctx->completion_lock, flags); } else { - ret = io_match_link(req, data); + ret = io_match_task(req, cancel->task, cancel->files); } return ret; } -static void io_attempt_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req) -{ - enum io_wq_cancel cret; - - /* cancel this particular work, if it's running */ - cret = io_wq_cancel_work(ctx->io_wq, &req->work); - if (cret != IO_WQ_CANCEL_NOTFOUND) - return; - - /* find links that hold this pending, cancel those */ - cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_link_cb, req, true); - if (cret != IO_WQ_CANCEL_NOTFOUND) - return; - - /* if we have a poll link holding this pending, cancel that */ - if (io_poll_remove_link(ctx, req)) - return; - - /* final option, timeout link is holding this req pending */ - io_timeout_remove_link(ctx, req); -} - static void io_cancel_defer_files(struct io_ring_ctx *ctx, struct task_struct *task, struct files_struct *files) @@ -8800,8 +8714,10 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, struct files_struct *files) { while (!list_empty_careful(&ctx->inflight_list)) { - struct io_kiocb *cancel_req = NULL, *req; + struct io_task_cancel cancel = { .task = task, .files = NULL, }; + struct io_kiocb *req; DEFINE_WAIT(wait); + bool found = false; spin_lock_irq(&ctx->inflight_lock); list_for_each_entry(req, &ctx->inflight_list, inflight_entry) { @@ -8809,23 +8725,21 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, (req->work.flags & IO_WQ_WORK_FILES) && req->work.identity->files != files) continue; - /* req is being completed, ignore */ - if (!refcount_inc_not_zero(&req->refs)) - continue; - cancel_req = req; + found = true; break; } - if (cancel_req) + if (found) prepare_to_wait(&ctx->inflight_wait, &wait, TASK_UNINTERRUPTIBLE); spin_unlock_irq(&ctx->inflight_lock); /* We need to keep going until we don't find a matching req */ - if (!cancel_req) + if (!found) break; - /* cancel this request, or head link requests */ - io_attempt_cancel(ctx, cancel_req); - io_put_req(cancel_req); + + io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true); + io_poll_remove_all(ctx, task, files); + io_kill_timeouts(ctx, task, files); /* cancellations _may_ trigger task work */ io_run_task_work(); schedule(); @@ -8833,22 +8747,15 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, } } -static bool io_cancel_task_cb(struct io_wq_work *work, void *data) -{ - struct io_kiocb *req = container_of(work, struct io_kiocb, work); - struct task_struct *task = data; - - return io_task_match(req, task); -} - static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx, struct task_struct *task) { while (1) { + struct io_task_cancel cancel = { .task = task, .files = NULL, }; enum io_wq_cancel cret; bool ret = false; - cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, task, true); + cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true); if (cret != IO_WQ_CANCEL_NOTFOUND) ret = true; -- cgit v1.2.3-59-g8ed1b