This is a note to let you know that I've just added the patch titled io_uring: deduplicate core cancellations sequence to the 5.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-deduplicate-core-cancellations-sequence.patch and it can be found in the queue-5.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Wed Mar 10 01:03:15 PM CET 2021 From: Pavel Begunkov <asml.silence@xxxxxxxxx> Date: Wed, 10 Mar 2021 11:30:38 +0000 Subject: io_uring: deduplicate core cancellations sequence To: stable@xxxxxxxxxxxxxxx Cc: Jens Axboe <axboe@xxxxxxxxx> Message-ID: <b4d938bd6cd39991672cbe5e7aae63de4f06cc49.1615375332.git.asml.silence@xxxxxxxxx> From: Pavel Begunkov <asml.silence@xxxxxxxxx> commit 9936c7c2bc76a0b2276f6d19de6d1d92f03deeab upstream Files and task cancellations go over same steps trying to cancel requests in io-wq, poll, etc. Deduplicate it with a helper. note: new io_uring_try_cancel_requests() is former __io_uring_cancel_task_requests() with files passed as an agrument and flushing overflowed requests. Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/io_uring.c | 85 +++++++++++++++++++++++++++------------------------------- 1 file changed, 40 insertions(+), 45 deletions(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -996,9 +996,9 @@ enum io_mem_account { ACCT_PINNED, }; -static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx, - struct task_struct *task); - +static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx, + struct task_struct *task, + struct files_struct *files); static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node); static struct fixed_file_ref_node *alloc_fixed_file_ref_node( struct io_ring_ctx *ctx); @@ -8780,7 +8780,7 @@ static void io_ring_exit_work(struct wor * as nobody else will be looking for them. */ do { - __io_uring_cancel_task_requests(ctx, NULL); + io_uring_try_cancel_requests(ctx, NULL, NULL); } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20)); io_ring_ctx_free(ctx); } @@ -8894,6 +8894,40 @@ static void io_cancel_defer_files(struct } } +static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx, + struct task_struct *task, + struct files_struct *files) +{ + struct io_task_cancel cancel = { .task = task, .files = files, }; + + while (1) { + enum io_wq_cancel cret; + bool ret = false; + + if (ctx->io_wq) { + cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, + &cancel, true); + ret |= (cret != IO_WQ_CANCEL_NOTFOUND); + } + + /* SQPOLL thread does its own polling */ + if (!(ctx->flags & IORING_SETUP_SQPOLL) && !files) { + while (!list_empty_careful(&ctx->iopoll_list)) { + io_iopoll_try_reap_events(ctx); + ret = true; + } + } + + ret |= io_poll_remove_all(ctx, task, files); + ret |= io_kill_timeouts(ctx, task, files); + ret |= io_run_task_work(); + io_cqring_overflow_flush(ctx, true, task, files); + if (!ret) + break; + cond_resched(); + } +} + static int io_uring_count_inflight(struct io_ring_ctx *ctx, struct task_struct *task, struct files_struct *files) @@ -8913,7 +8947,6 @@ static void io_uring_cancel_files(struct struct files_struct *files) { while (!list_empty_careful(&ctx->inflight_list)) { - struct io_task_cancel cancel = { .task = task, .files = files }; DEFINE_WAIT(wait); int inflight; @@ -8921,13 +8954,7 @@ static void io_uring_cancel_files(struct if (!inflight) break; - 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); - io_cqring_overflow_flush(ctx, true, task, files); - /* cancellations _may_ trigger task work */ - io_run_task_work(); - + io_uring_try_cancel_requests(ctx, task, files); prepare_to_wait(&task->io_uring->wait, &wait, TASK_UNINTERRUPTIBLE); if (inflight == io_uring_count_inflight(ctx, task, files)) @@ -8936,37 +8963,6 @@ static void io_uring_cancel_files(struct } } -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; - - if (ctx->io_wq) { - cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, - &cancel, true); - ret |= (cret != IO_WQ_CANCEL_NOTFOUND); - } - - /* SQPOLL thread does its own polling */ - if (!(ctx->flags & IORING_SETUP_SQPOLL)) { - while (!list_empty_careful(&ctx->iopoll_list)) { - io_iopoll_try_reap_events(ctx); - ret = true; - } - } - - ret |= io_poll_remove_all(ctx, task, NULL); - ret |= io_kill_timeouts(ctx, task, NULL); - ret |= io_run_task_work(); - if (!ret) - break; - cond_resched(); - } -} - static void io_disable_sqo_submit(struct io_ring_ctx *ctx) { mutex_lock(&ctx->uring_lock); @@ -8996,11 +8992,10 @@ static void io_uring_cancel_task_request } io_cancel_defer_files(ctx, task, files); - io_cqring_overflow_flush(ctx, true, task, files); io_uring_cancel_files(ctx, task, files); if (!files) - __io_uring_cancel_task_requests(ctx, task); + io_uring_try_cancel_requests(ctx, task, NULL); if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { atomic_dec(&task->io_uring->in_idle); Patches currently in stable-queue which might be from asml.silence@xxxxxxxxx are queue-5.11/io_uring-io-wq-kill-off-now-unused-io_wq_work_no_cancel.patch queue-5.11/io_uring-get-rid-of-intermediate-ioring_op_close-stage.patch queue-5.11/io_uring-fix-inconsistent-lock-state.patch queue-5.11/fs-provide-locked-helper-variant-of-close_fd_get_file.patch queue-5.11/io_uring-io-wq-return-2-step-work-swap-scheme.patch queue-5.11/io_uring-deduplicate-core-cancellations-sequence.patch queue-5.11/io_uring-unpark-sqpoll-thread-for-cancelation.patch queue-5.11/io_uring-don-t-take-uring_lock-during-iowq-cancel.patch queue-5.11/io_uring-deduplicate-failing-task_work_add.patch