Commit 698bdfa0 authored by John Snow's avatar John Snow Committed by Kevin Wolf
Browse files

blockdev: use drained_begin/end for qmp_block_resize 

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1447551



If one tries to issue a block_resize while a guest is busy
accessing the disk, it is possible that qemu may deadlock
when invoking aio_poll from both the main loop and the iothread.

Replace another instance of bdrv_drain_all that doesn't
quite belong.

Cc: qemu-stable@nongnu.org
Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarJohn Snow <jsnow@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent c03e7ef1

blockdev.c

+2 −3
Original line number Diff line number Diff line
@@ -2923,10 +2923,9 @@ void qmp_block_resize(bool has_device, const char *device, 
        goto out;

    }



    /* complete all in-flight operations before resizing the device */

    bdrv_drain_all();



    bdrv_drained_begin(bs);

    ret = blk_truncate(blk, size, errp);

    bdrv_drained_end(bs);



out:

    blk_unref(blk);