Commit 80308d33 authored by MORITA Kazutaka's avatar MORITA Kazutaka Committed by Kevin Wolf
Browse files

sheepdog: check simultaneous create in resend_aioreq 



After reconnection happens, all the inflight requests are moved to the
failed request list.  As a result, sd_co_rw_vector() can send another
create request before resend_aioreq() resends a create request from
the failed list.

This patch adds a helper function check_simultaneous_create() and
checks simultaneous create requests more strictly in resend_aioreq().

Signed-off-by: default avatarMORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Tested-by: default avatarLiu Yuan <namei.unix@gmail.com>
Reviewed-by: default avatarLiu Yuan <namei.unix@gmail.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 35200687

block/sheepdog.c

+32 −32
Original line number Diff line number Diff line
@@ -1288,6 +1288,29 @@ out: 
    return ret;

}



/* Return true if the specified request is linked to the pending list. */

static bool check_simultaneous_create(BDRVSheepdogState *s, AIOReq *aio_req)

{

    AIOReq *areq;

    QLIST_FOREACH(areq, &s->inflight_aio_head, aio_siblings) {

        if (areq != aio_req && areq->oid == aio_req->oid) {

            /*

             * Sheepdog cannot handle simultaneous create requests to the same

             * object, so we cannot send the request until the previous request

             * finishes.

             */

            DPRINTF("simultaneous create to %" PRIx64 "\n", aio_req->oid);

            aio_req->flags = 0;

            aio_req->base_oid = 0;

            QLIST_REMOVE(aio_req, aio_siblings);

            QLIST_INSERT_HEAD(&s->pending_aio_head, aio_req, aio_siblings);

            return true;

        }

    }



    return false;

}



static void coroutine_fn resend_aioreq(BDRVSheepdogState *s, AIOReq *aio_req)

{

    SheepdogAIOCB *acb = aio_req->aiocb;
@@ -1296,29 +1319,19 @@ static void coroutine_fn resend_aioreq(BDRVSheepdogState *s, AIOReq *aio_req) 
    /* check whether this request becomes a CoW one */

    if (acb->aiocb_type == AIOCB_WRITE_UDATA && is_data_obj(aio_req->oid)) {

        int idx = data_oid_to_idx(aio_req->oid);

        AIOReq *areq;



        if (s->inode.data_vdi_id[idx] == 0) {

            create = true;

            goto out;

        }

        if (is_data_obj_writable(&s->inode, idx)) {

            goto out;

        }



        /* link to the pending list if there is another CoW request to

         * the same object */

        QLIST_FOREACH(areq, &s->inflight_aio_head, aio_siblings) {

            if (areq != aio_req && areq->oid == aio_req->oid) {

                DPRINTF("simultaneous CoW to %" PRIx64 "\n", aio_req->oid);

                QLIST_REMOVE(aio_req, aio_siblings);

                QLIST_INSERT_HEAD(&s->pending_aio_head, aio_req, aio_siblings);

        if (check_simultaneous_create(s, aio_req)) {

            return;

        }

        }



        if (s->inode.data_vdi_id[idx]) {

            aio_req->base_oid = vid_to_data_oid(s->inode.data_vdi_id[idx], idx);

            aio_req->flags |= SD_FLAG_CMD_COW;

        }

        create = true;

    }

out:
@@ -1945,27 +1958,14 @@ static int coroutine_fn sd_co_rw_vector(void *p) 
        }



        aio_req = alloc_aio_req(s, acb, oid, len, offset, flags, old_oid, done);

        QLIST_INSERT_HEAD(&s->inflight_aio_head, aio_req, aio_siblings);



        if (create) {

            AIOReq *areq;

            QLIST_FOREACH(areq, &s->inflight_aio_head, aio_siblings) {

                if (areq->oid == oid) {

                    /*

                     * Sheepdog cannot handle simultaneous create

                     * requests to the same object.  So we cannot send

                     * the request until the previous request

                     * finishes.

                     */

                    aio_req->flags = 0;

                    aio_req->base_oid = 0;

                    QLIST_INSERT_HEAD(&s->pending_aio_head, aio_req,

                                      aio_siblings);

            if (check_simultaneous_create(s, aio_req)) {

                goto done;

            }

        }

        }



        QLIST_INSERT_HEAD(&s->inflight_aio_head, aio_req, aio_siblings);

        add_aio_request(s, aio_req, acb->qiov->iov, acb->qiov->niov, create,

                        acb->aiocb_type);

    done: