Commit 35f106e6 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Stefan Hajnoczi
Browse files

block-backend: allow blk_prw from coroutine context 



qcow2_create2 calls this.  Do not run a nested event loop, as that
breaks when aio_co_wake tries to queue the coroutine on the co_queue_wakeup
list of the currently running one.

Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-4-pbonzini@redhat.com
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 0c330a73

block/block-backend.c

+8 −4
Original line number Diff line number Diff line
@@ -880,7 +880,6 @@ static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, 
{

    QEMUIOVector qiov;

    struct iovec iov;

    Coroutine *co;

    BlkRwCo rwco;



    iov = (struct iovec) {
@@ -897,9 +896,14 @@ static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, 
        .ret    = NOT_DONE,

    };



    co = qemu_coroutine_create(co_entry, &rwco);

    if (qemu_in_coroutine()) {

        /* Fast-path if already in coroutine context */

        co_entry(&rwco);

    } else {

        Coroutine *co = qemu_coroutine_create(co_entry, &rwco);

        qemu_coroutine_enter(co);

        BDRV_POLL_WHILE(blk_bs(blk), rwco.ret == NOT_DONE);

    }



    return rwco.ret;

}