Drop the assumption that we're using the main AioContext for raw-win32.
Convert the aio-win32 code to support detach/attach and replace
qemu_aio_wait() with aio_poll().
The .bdrv_detach/attach_aio_context() interfaces move the aio-win32
event notifier from the old to the new AioContext.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Each QEMUWin32AIOState event notifier is associated with an AioContext.
Since BlockDriverState instances can use different AioContexts we cannot
continue to use a global QEMUWin32AIOState.
Let each BDRVRawState have its own QEMUWin32AIOState and free it when
BDRVRawState is closed.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Hot unplugging -drive aio=native,file=test.img,format=raw images leaves
the Linux AIO event notifier and struct qemu_laio_state allocated.
Luckily nothing will use the event notifier after the BlockDriverState
has been closed so the handler function is never called.
It's still worth fixing this resource leak.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Drop the assumption that we're using the main AioContext for Linux AIO.
Convert the Linux AIO event notifier to use aio_set_event_notifier().
The .bdrv_detach/attach_aio_context() interfaces also need to be
implemented to move the event notifier handler from the old to the new
AioContext.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The code is similar to the implementation of discard and write_zeroes
with UNMAP. However, failure must be propagated up to block.c.
The stale page cache problem can be reproduced as follows:
# modprobe scsi-debug lbpws=1 lbprz=1
# ./qemu-io /dev/sdXX
qemu-io> write -P 0xcc 0 2M
qemu-io> write -z 0 1M
qemu-io> read -P 0x00 0 512
Pattern verification failed at offset 0, 512 bytes
qemu-io> read -v 0 512
00000000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................
...
# ./qemu-io --cache=none /dev/sdXX
qemu-io> write -P 0xcc 0 2M
qemu-io> write -z 0 1M
qemu-io> read -P 0x00 0 512
qemu-io> read -v 0 512
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
...
And similarly with discard instead of "write -z".
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This is easy with the thread pool, because we can use s->is_xfs and
s->has_discard from the worker function.
QEMU has a widespread assumption that each I/O operation writes less
than 2^32 bytes. This patch doesn't fix it throughout of course,
but it starts correcting struct RawPosixAIOData so that there is
no regression with respect to the synchronous discard implementation.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
With the new support for EventNotifiers in the AIO event loop, we
can hook a completion port to every opened file and use asynchronous
I/O on them.
Wine's support is extremely inefficient, also because it really does
the I/O synchronously on regular files. (!) But it works, and it is
good to keep the Win32 and POSIX ports as similar as possible.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
