Commit 463e0be1 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi
Browse files

blockjob: add AioContext attached callback 



Block jobs that use additional BDSes or event loop resources need a
callback to get their affairs in order when the AioContext is switched.

Simple block jobs don't need an attach callback, they automatically work
thanks to the generic attach/detach notifiers that this patch adds.

Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Message-id: 1466096189-6477-7-git-send-email-stefanha@redhat.com
parent e8a095da

blockjob.c

+38 −0
Original line number Diff line number Diff line
@@ -71,6 +71,38 @@ static AioContext *block_job_get_aio_context(BlockJob *job) 
           blk_get_aio_context(job->blk);

}



static void block_job_attached_aio_context(AioContext *new_context,

                                           void *opaque)

{

    BlockJob *job = opaque;



    if (job->driver->attached_aio_context) {

        job->driver->attached_aio_context(job, new_context);

    }



    block_job_resume(job);

}



static void block_job_detach_aio_context(void *opaque)

{

    BlockJob *job = opaque;



    /* In case the job terminates during aio_poll()... */

    block_job_ref(job);



    block_job_pause(job);



    if (!job->paused) {

        /* If job is !job->busy this kicks it into the next pause point. */

        block_job_enter(job);

    }

    while (!job->paused && !job->completed) {

        aio_poll(block_job_get_aio_context(job), true);

    }



    block_job_unref(job);

}



void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,

                       int64_t speed, BlockCompletionFunc *cb,

                       void *opaque, Error **errp)
@@ -103,6 +135,9 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs, 


    QLIST_INSERT_HEAD(&block_jobs, job, job_list);



    blk_add_aio_context_notifier(blk, block_job_attached_aio_context,

                                 block_job_detach_aio_context, job);



    /* Only set speed when necessary to avoid NotSupported error */

    if (speed != 0) {

        Error *local_err = NULL;
@@ -128,6 +163,9 @@ void block_job_unref(BlockJob *job) 
        BlockDriverState *bs = blk_bs(job->blk);

        bs->job = NULL;

        bdrv_op_unblock_all(bs, job->blocker);

        blk_remove_aio_context_notifier(job->blk,

                                        block_job_attached_aio_context,

                                        block_job_detach_aio_context, job);

        blk_unref(job->blk);

        error_free(job->blocker);

        g_free(job->id);

include/block/blockjob.h

+7 −0
Original line number Diff line number Diff line
@@ -84,6 +84,13 @@ typedef struct BlockJobDriver { 
     * should be restarted from this callback.

     */

    void coroutine_fn (*resume)(BlockJob *job);



    /*

     * If the callback is not NULL, it will be invoked before the job is

     * resumed in a new AioContext.  This is the place to move any resources

     * besides job->blk to the new AioContext.

     */

    void (*attached_aio_context)(BlockJob *job, AioContext *new_context);

} BlockJobDriver;



/**