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Merge tag 'io_uring-5.12-2021-03-05' of git://git.kernel.dk/linux-block

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Pull io_uring fixes from Jens Axboe:
 "A bit of a mix between fallout from the worker change, cleanups and
  reductions now possible from that change, and fixes in general. In
  detail:

   - Fully serialize manager and worker creation, fixing races due to
     that.

   - Clean up some naming that had gone stale.

   - SQPOLL fixes.

   - Fix race condition around task_work rework that went into this
     merge window.

   - Implement unshare. Used for when the original task does unshare(2)
     or setuid/seteuid and friends, drops the original workers and forks
     new ones.

   - Drop the only remaining piece of state shuffling we had left, which
     was cred. Move it into issue instead, and we can drop all of that
     code too.

   - Kill f_op->flush() usage. That was such a nasty hack that we had
     out of necessity, we no longer need it.

   - Following from ->flush() removal, we can also drop various bits of
     ctx state related to SQPOLL and cancelations.

   - Fix an issue with IOPOLL retry, which originally was fallout from a
     filemap change (removing iov_iter_revert()), but uncovered an issue
     with iovec re-import too late.

   - Fix an issue with system suspend.

   - Use xchg() for fallback work, instead of cmpxchg().

   - Properly destroy io-wq on exec.

   - Add create_io_thread() core helper, and use that in io-wq and
     io_uring. This allows us to remove various silly completion events
     related to thread setup.

   - A few error handling fixes.

  This should be the grunt of fixes necessary for the new workers, next
  week should be quieter. We've got a pending series from Pavel on
  cancelations, and how tasks and rings are indexed. Outside of that,
  should just be minor fixes. Even with these fixes, we're still killing
  a net ~80 lines"

* tag 'io_uring-5.12-2021-03-05' of git://git.kernel.dk/linux-block: (41 commits)
  io_uring: don't restrict issue_flags for io_openat
  io_uring: make SQPOLL thread parking saner
  io-wq: kill hashed waitqueue before manager exits
  io_uring: clear IOCB_WAITQ for non -EIOCBQUEUED return
  io_uring: don't keep looping for more events if we can't flush overflow
  io_uring: move to using create_io_thread()
  kernel: provide create_io_thread() helper
  io_uring: reliably cancel linked timeouts
  io_uring: cancel-match based on flags
  io-wq: ensure all pending work is canceled on exit
  io_uring: ensure that threads freeze on suspend
  io_uring: remove extra in_idle wake up
  io_uring: inline __io_queue_async_work()
  io_uring: inline io_req_clean_work()
  io_uring: choose right tctx->io_wq for try cancel
  io_uring: fix -EAGAIN retry with IOPOLL
  io-wq: fix error path leak of buffered write hash map
  io_uring: remove sqo_task
  io_uring: kill sqo_dead and sqo submission halting
  io_uring: ignore double poll add on the same waitqueue head
  ...
This commit is contained in:
Linus Torvalds
2021-03-05 12:44:43 -08:00
parent 6d47254c06 e45cff5885
commit f292e8730a
6 changed files with 362 additions and 440 deletions
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30
kernel/fork.c
View File

@@ -1940,6 +1940,8 @@ static __latent_entropy struct task_struct *copy_process(
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
@@ -2410,6 +2412,34 @@ struct mm_struct *copy_init_mm(void)
return dup_mm(NULL, &init_mm);
}
/*
* 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.
*