This is a note to let you know that I've just added the patch titled
io_uring: handle TIF_NOTIFY_RESUME when checking for task_work
to the 6.2-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-handle-tif_notify_resume-when-checking-for-task_work.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b5d3ae202fbfe055aa2a8ae8524531ee1dcab717 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Tue, 24 Jan 2023 08:24:25 -0700
Subject: io_uring: handle TIF_NOTIFY_RESUME when checking for task_work
From: Jens Axboe <axboe@xxxxxxxxx>
commit b5d3ae202fbfe055aa2a8ae8524531ee1dcab717 upstream.
If TIF_NOTIFY_RESUME is set, then we need to call resume_user_mode_work()
for PF_IO_WORKER threads. They never return to usermode, hence never get
a chance to process any items that are marked by this flag. Most notably
this includes the final put of files, but also any throttling markers set
by block cgroups.
Cc: stable@xxxxxxxxxxxxxxx # 5.10+
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/io_uring.h | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -3,6 +3,7 @@
#include <linux/errno.h>
#include <linux/lockdep.h>
+#include <linux/resume_user_mode.h>
#include <linux/io_uring_types.h>
#include <uapi/linux/eventpoll.h>
#include "io-wq.h"
@@ -270,6 +271,13 @@ static inline int io_run_task_work(void)
*/
if (test_thread_flag(TIF_NOTIFY_SIGNAL))
clear_notify_signal();
+ /*
+ * PF_IO_WORKER never returns to userspace, so check here if we have
+ * notify work that needs processing.
+ */
+ if (current->flags & PF_IO_WORKER &&
+ test_thread_flag(TIF_NOTIFY_RESUME))
+ resume_user_mode_work(NULL);
if (task_work_pending(current)) {
__set_current_state(TASK_RUNNING);
task_work_run();
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-6.2/io_uring-handle-tif_notify_resume-when-checking-for-task_work.patch
queue-6.2/block-don-t-allow-multiple-bios-for-iocb_nowait-issue.patch
queue-6.2/sbitmap-correct-wake_batch-recalculation-to-avoid-po.patch
queue-6.2/blk-mq-avoid-sleep-in-blk_mq_alloc_request_hctx.patch
queue-6.2/io_uring-add-reschedule-point-to-handle_tw_list.patch
queue-6.2/ublk_drv-remove-nr_aborted_queues-from-ublk_device.patch
queue-6.2/io_uring-remove-msg_nosignal-from-recvmsg.patch
queue-6.2/blk-mq-fix-potential-io-hung-for-shared-sbitmap-per-.patch
queue-6.2/blk-mq-wait-on-correct-sbitmap_queue-in-blk_mq_mark_.patch
queue-6.2/block-clear-bio-bi_bdev-when-putting-a-bio-back-in-the-cache.patch
queue-6.2/io_uring-fix-fget-leak-when-fs-don-t-support-nowait-buffered-read.patch
queue-6.2/ublk_drv-don-t-probe-partitions-if-the-ubq-daemon-is.patch
queue-6.2/trace-blktrace-fix-memory-leak-with-using-debugfs_lo.patch
queue-6.2/io_uring-audit-don-t-log-ioring_op_madvise.patch
queue-6.2/io_uring-rsrc-disallow-multi-source-reg-buffers.patch
queue-6.2/x86-fpu-don-t-set-tif_need_fpu_load-for-pf_io_worker.patch
queue-6.2/io_uring-replace-0-length-array-with-flexible-array.patch
queue-6.2/blk-cgroup-dropping-parent-refcount-after-pd_free_fn.patch
queue-6.2/block-be-a-bit-more-careful-in-checking-for-null-bdev-while-polling.patch
queue-6.2/block-use-proper-return-value-from-bio_failfast.patch
queue-6.2/block-fix-io-statistics-for-cgroup-in-throttle-path.patch
queue-6.2/block-ublk-check-io-buffer-based-on-flag-need_get_da.patch
queue-6.2/io_uring-use-user-visible-tail-in-io_uring_poll.patch
queue-6.2/blk-cgroup-synchronize-pd_free_fn-from-blkg_free_wor.patch
queue-6.2/sbitmap-remove-redundant-check-in-__sbitmap_queue_ge.patch
queue-6.2/io_uring-poll-allow-some-retries-for-poll-triggering-spuriously.patch
queue-6.2/block-sync-mixed-merged-request-s-failfast-with-1st-.patch
queue-6.2/blk-mq-remove-stale-comment-for-blk_mq_sched_mark_re.patch
queue-6.2/blk-iocost-fix-divide-by-0-error-in-calc_lcoefs.patch
queue-6.2/s390-dasd-fix-potential-memleak-in-dasd_eckd_init.patch
queue-6.2/blk-mq-correct-stale-comment-of-.get_budget.patch
queue-6.2/io_uring-add-a-conditional-reschedule-to-the-iopoll-cancelation-loop.patch
queue-6.2/block-bio-integrity-copy-flags-when-bio_integrity_pa.patch
