Else there may be magic numbers in /sys/kernel/debug/block/*/state.

Signed-off-by: Hou Tao <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

Make blk_ksm_destroy() use the kvfree_sensitive() function (which was
introduced in v5.8-rc1) instead of open-coding it.

Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

So that the target task will exit the wait_event_interruptible-like
loop and call task_work_run() asap.

The patch turns "bool notify" into 0,TWA_RESUME,TWA_SIGNAL enum, the
new TWA_SIGNAL flag implies signal_wake_up().  However, it needs to
avoid the race with recalc_sigpending(), so the patch also adds the
new JOBCTL_TASK_WORK bit included in JOBCTL_PENDING_MASK.

TODO: once this patch is merged we need to change all current users
of task_work_add(notify = true) to use TWA_RESUME.

Cc: [email protected] # v5.7
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Oleg Nesterov <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

Since 5.7, we've been using task_work to trigger async running of
requests in the context of the original task. This generally works
great, but there's a case where if the task is currently blocked
in the kernel waiting on a condition to become true, it won't process
task_work. Even though the task is woken, it just checks whatever
condition it's waiting on, and goes back to sleep if it's still false.

This is a problem if that very condition only becomes true when that
task_work is run. An example of that is the task registering an eventfd
with io_uring, and it's now blocked waiting on an eventfd read. That
read could depend on a completion event, and that completion event
won't get trigged until task_work has been run.

Use the TWA_SIGNAL notification for task_work, so that we ensure that
the task always runs the work when queued.

Cc: [email protected] # v5.7
Signed-off-by: Jens Axboe <[email protected]>

Else there will be memory leak if alloc_disk() fails.

Fixes: 6a27b65 ("block: virtio-blk: support multi virt queues per virtio-blk device")
Signed-off-by: Hou Tao <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

Pull io_uring fixes from Jens Axboe:
 "One fix in here, for a regression in 5.7 where a task is waiting in
  the kernel for a condition, but that condition won't become true until
  task_work is run. And the task_work can't be run exactly because the
  task is waiting in the kernel, so we'll never make any progress.

  One example of that is registering an eventfd and queueing io_uring
  work, and then the task goes and waits in eventfd read with the
  expectation that it'll get woken (and read an event) when the io_uring
  request completes. The io_uring request is finished through task_work,
  which won't get run while the task is looping in eventfd read"

* tag 'io_uring-5.8-2020-07-01' of git://git.kernel.dk/linux-block:
  io_uring: use signal based task_work running
  task_work: teach task_work_add() to do signal_wake_up()

Pull block fixes from Jens Axboe:

 - Use kvfree_sensitive() for the block keyslot free (Eric)

 - Sync blk-mq debugfs flags (Hou)

 - Memory leak fix in virtio-blk error path (Hou)

* tag 'block-5.8-2020-07-01' of git://git.kernel.dk/linux-block:
  virtio-blk: free vblk-vqs in error path of virtblk_probe()
  block/keyslot-manager: use kvfree_sensitive()
  blk-mq-debugfs: update blk_queue_flag_name[] accordingly for new flags