Commit Graph

10 Commits

Author SHA1 Message Date
Kevin Wolf b161e2e4b3 linux-aio: Allow reads beyond the end of growable images
This is the linux-aio version of commits 22afa7b5 (raw-posix, synchronous) and
ba1d1afd (posix-aio-compat). Reads now produce zeros after the end of file
instead of failing or resulting in short reads, making linux-aio compatible
with the behaviour of synchronous raw-posix requests and posix-aio-compat.

The problem can be reproduced like this:

dd if=/dev/zero of=/tmp/test.raw bs=1 count=1234
./qemu-io -k -n -g -c 'read -p 1024 512' /tmp/test.raw

Previously, the result of this was 'read failed: Invalid argument', now the
read completes successfully.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-10-14 10:29:13 +02:00
Kevin Wolf 449c184ed2 linux-aio: Fix laio_submit error handling
The error handling order was in the wrong order, so that either the ACB would
be leaked or the counter would be decremented when it shouldn't.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-11 09:41:47 +02:00
Paolo Bonzini cf26a4e6f8 linux-aio: remove process requests callback
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-20 14:34:17 +02:00
Frediano Ziglio c30e624d5d linux aio: some comments
Add some notes about Linux AIO explaining why we don't use AIO in
some situations.

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06 11:23:51 +02:00
Anthony Liguori 7267c0947d Use glib memory allocation and free functions
qemu_malloc/qemu_free no longer exist after this commit.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-20 23:01:08 -05:00
Kevin Wolf 384acbf46b async: Remove AsyncContext
The purpose of AsyncContexts was to protect qcow and qcow2 against reentrancy
during an emulated bdrv_read/write (which includes a qemu_aio_wait() call and
can run AIO callbacks of different requests if it weren't for AsyncContexts).

Now both qcow and qcow2 are protected by CoMutexes and AsyncContexts can be
removed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-02 15:53:41 +02:00
Stefan Hajnoczi 2be5064953 linux-aio: Fix typo in read() EINTR check
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23 16:21:57 +02:00
Kevin Wolf db0ffc2402 linux-aio: Honour AsyncContext
Also for Linux AIO, don't call callbacks that don't belong to the active
AsyncContext.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Kevin Wolf 8febfa2684 Add qemu_aio_process_queue()
We'll leave some AIO completions unhandled when we can't call the callback.
qemu_aio_process_queue() is used later to run any callbacks that are left and
can be run then.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Christoph Hellwig 5c6c3a6c54 raw-posix: add Linux native AIO support
Now that do have a nicer interface to work against we can add Linux native
AIO support.  It's an extremly thing layer just setting up an iocb for
the io_submit system call in the submission path, and registering an
eventfd with the qemu poll handler to do complete the iocbs directly
from there.

This started out based on Anthony's earlier AIO patch, but after
estimated 42,000 rewrites and just as many build system changes
there's not much left of it.

To enable native kernel aio use the aio=native sub-command on the
drive command line.  I have also added an option to qemu-io to
test the aio support without needing a guest.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-08-27 20:30:22 -05:00