This is a note to let you know that I've just added the patch titled
kernel: provide create_io_thread() helper
to the 5.10-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:
kernel-provide-create_io_thread-helper.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a3db03dc7a4f33de20188638d5b193c2946c5dfe Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Thu, 4 Mar 2021 12:21:05 -0700
Subject: kernel: provide create_io_thread() helper
From: Jens Axboe <axboe@xxxxxxxxx>
[ Upstream commit cc440e8738e5c875297ac0e90316745093be7e28 ]
Provide a generic helper for setting up an io_uring worker. Returns a
task_struct so that the caller can do whatever setup is needed, then call
wake_up_new_task() to kick it into gear.
Add a kernel_clone_args member, io_thread, which tells copy_process() to
mark the task with PF_IO_WORKER.
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/sched/task.h | 2 ++
kernel/fork.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 32 insertions(+)
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -31,6 +31,7 @@ struct kernel_clone_args {
/* Number of elements in *set_tid */
size_t set_tid_size;
int cgroup;
+ int io_thread;
struct cgroup *cgrp;
struct css_set *cset;
};
@@ -85,6 +86,7 @@ extern void exit_files(struct task_struc
extern void exit_itimers(struct task_struct *);
extern pid_t kernel_clone(struct kernel_clone_args *kargs);
+struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);
struct task_struct *fork_idle(int);
struct mm_struct *copy_init_mm(void);
extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1949,6 +1949,8 @@ static __latent_entropy struct task_stru
p = dup_task_struct(current, node);
if (!p)
goto fork_out;
+ if (args->io_thread)
+ p->flags |= PF_IO_WORKER;
/*
* This _must_ happen before we call free_task(), i.e. before we jump
@@ -2416,6 +2418,34 @@ struct mm_struct *copy_init_mm(void)
}
/*
+ * This is like kernel_clone(), but shaved down and tailored to just
+ * creating io_uring workers. It returns a created task, or an error pointer.
+ * The returned task is inactive, and the caller must fire it up through
+ * wake_up_new_task(p). All signals are blocked in the created task.
+ */
+struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node)
+{
+ unsigned long flags = CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|
+ CLONE_IO;
+ struct kernel_clone_args args = {
+ .flags = ((lower_32_bits(flags) | CLONE_VM |
+ CLONE_UNTRACED) & ~CSIGNAL),
+ .exit_signal = (lower_32_bits(flags) & CSIGNAL),
+ .stack = (unsigned long)fn,
+ .stack_size = (unsigned long)arg,
+ .io_thread = 1,
+ };
+ struct task_struct *tsk;
+
+ tsk = copy_process(NULL, 0, node, &args);
+ if (!IS_ERR(tsk)) {
+ sigfillset(&tsk->blocked);
+ sigdelsetmask(&tsk->blocked, sigmask(SIGKILL));
+ }
+ return tsk;
+}
+
+/*
* Ok, this is the main fork-routine.
*
* It copies the process, and if successful kick-starts
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-5.10/x86-process-setup-io_threads-more-like-normal-user-space-threads.patch
queue-5.10/powerpc-add-support-for-tif_notify_signal.patch
queue-5.10/eventfd-provide-a-eventfd_signal_mask-helper.patch
queue-5.10/fs-provide-locked-helper-variant-of-close_fd_get_file.patch
queue-5.10/relay-fix-type-mismatch-when-allocating-memory-in-re.patch
queue-5.10/eventfd-change-int-to-__u64-in-eventfd_signal-ifndef.patch
queue-5.10/io_uring-pass-in-epoll_uring_wake-for-eventfd-signaling-and-wakeups.patch
queue-5.10/blk-mq-fix-possible-memleak-when-register-hctx-faile.patch
queue-5.10/fix-handling-of-nd-depth-on-lookup_cached-failures-in-try_to_unlazy.patch
queue-5.10/net-provide-__sys_shutdown_sock-that-takes-a-socket.patch
queue-5.10/task_work-unconditionally-run-task_work-from-get_signal.patch
queue-5.10/openrisc-add-support-for-tif_notify_signal.patch
queue-5.10/signal-add-task_sigpending-helper.patch
queue-5.10/net-remove-cmsg-restriction-from-io_uring-based-send-recvmsg-calls.patch
queue-5.10/alpha-add-support-for-tif_notify_signal.patch
queue-5.10/nios32-add-support-for-tif_notify_signal.patch
queue-5.10/ia64-don-t-call-handle_signal-unless-there-s-actually-a-signal-queued.patch
queue-5.10/task_work-remove-legacy-twa_signal-path.patch
queue-5.10/revert-proc-don-t-allow-async-path-resolution-of-proc-self-components.patch
queue-5.10/m68k-add-support-for-tif_notify_signal.patch
queue-5.10/s390-add-support-for-tif_notify_signal.patch
queue-5.10/um-add-support-for-tif_notify_signal.patch
queue-5.10/tools-headers-uapi-sync-openat2.h-with-the-kernel-sources.patch
queue-5.10/kernel-provide-create_io_thread-helper.patch
queue-5.10/iov_iter-add-helper-to-save-iov_iter-state.patch
queue-5.10/arc-unbork-5.11-bootup-fix-snafu-in-_tif_notify_signal-handling.patch
queue-5.10/arch-ensure-parisc-powerpc-handle-pf_io_worker-in-copy_thread.patch
queue-5.10/csky-add-support-for-tif_notify_signal.patch
queue-5.10/arm-add-support-for-tif_notify_signal.patch
queue-5.10/kernel-stop-masking-signals-in-create_io_thread.patch
queue-5.10/fs-expose-lookup_cached-through-openat2-resolve_cached.patch
queue-5.10/task_work-add-helper-for-more-targeted-task_work-canceling.patch
queue-5.10/nds32-add-support-for-tif_notify_signal.patch
queue-5.10/signal-kill-jobctl_task_work.patch
queue-5.10/hexagon-add-support-for-tif_notify_signal.patch
queue-5.10/sh-add-support-for-tif_notify_signal.patch
queue-5.10/riscv-add-support-for-tif_notify_signal.patch
queue-5.10/h8300-add-support-for-tif_notify_signal.patch
queue-5.10/io_uring-import-5.15-stable-io_uring.patch
queue-5.10/sparc-add-support-for-tif_notify_signal.patch
queue-5.10/blktrace-fix-output-non-blktrace-event-when-blk_clas.patch
queue-5.10/eventpoll-add-epoll_uring_wake-poll-wakeup-flag.patch
queue-5.10/parisc-add-support-for-tif_notify_signal.patch
queue-5.10/entry-add-support-for-tif_notify_signal.patch
queue-5.10/x86-wire-up-tif_notify_signal.patch
queue-5.10/task_work-use-tif_notify_signal-if-available.patch
queue-5.10/drbd-fix-an-invalid-memory-access-caused-by-incorrec.patch
queue-5.10/kernel-don-t-call-do_exit-for-pf_io_worker-threads.patch
queue-5.10/kernel-allow-fork-with-tif_notify_signal-pending.patch
queue-5.10/pata_ipx4xx_cf-fix-unsigned-comparison-with-less-tha.patch
queue-5.10/mips-add-support-for-tif_notify_signal.patch
queue-5.10/xtensa-add-support-for-tif_notify_signal.patch
queue-5.10/c6x-add-support-for-tif_notify_signal.patch
queue-5.10/microblaze-add-support-for-tif_notify_signal.patch
queue-5.10/net-add-accept-helper-not-installing-fd.patch
queue-5.10/ia64-add-support-for-tif_notify_signal.patch
queue-5.10/arm64-add-support-for-tif_notify_signal.patch
queue-5.10/arc-add-support-for-tif_notify_signal.patch
queue-5.10/revert-proc-don-t-allow-async-path-resolution-of-proc-thread-self-components.patch
queue-5.10/fs-make-do_renameat2-take-struct-filename.patch
queue-5.10/kernel-remove-checking-for-tif_notify_signal.patch
queue-5.10/arch-setup-pf_io_worker-threads-like-pf_kthread.patch
queue-5.10/nvme-pci-fix-mempool-alloc-size.patch
queue-5.10/fs-add-support-for-lookup_cached.patch
