[sheepdog] [PATCH v3 2/3] sheep: make push_cache_object() queue a local gateway request

[Yunkai Zhang]

On Wed, Jun 27, 2012 at 11:07 AM, levin li <levin108 at gmail.com> wrote:
> From: levin li <xingke.lwp at taobao.com>
>
> The same reason as write/read/remove_object(), push_cache_object()
> also needs a retrying machanism like gateway, so we also queue a
> local gateway request instead of directly calling forward_write_obj_req().
>
> Signed-off-by: levin li <xingke.lwp at taobao.com>
> ---
>  sheep/gateway.c      |    3 ++-
>  sheep/object_cache.c |   24 ++++++++----------------
>  2 files changed, 10 insertions(+), 17 deletions(-)
>
> diff --git a/sheep/gateway.c b/sheep/gateway.c
> index 42f028a..18ab926 100644
> --- a/sheep/gateway.c
> +++ b/sheep/gateway.c
> @@ -216,7 +216,8 @@ void do_gateway_request(struct work *work)
>        dprintf("%x, %" PRIx64" , %u\n",
>                req->rq.opcode, req->rq.obj.oid, req->rq.epoch);
>
> -       if (!sys->enable_write_cache || bypass_object_cache(req)) {
> +       if (!sys->enable_write_cache || req->local ||
> +           bypass_object_cache(req)) {
>                if (req->rq.flags & SD_FLAG_CMD_WRITE)
>                        ret = forward_write_obj_req(req);
>                else
> diff --git a/sheep/object_cache.c b/sheep/object_cache.c
> index 1854a77..e538cda 100644
> --- a/sheep/object_cache.c
> +++ b/sheep/object_cache.c
> @@ -552,8 +552,7 @@ static uint64_t idx_to_oid(uint32_t vid, uint32_t idx)
>  static int push_cache_object(struct vnode_info *vnode_info, uint32_t vid,
>                             uint32_t idx, uint64_t bmap, int create)
>  {
> -       struct request fake_req;
> -       struct sd_req *hdr = &fake_req.rq;
> +       struct sd_req hdr;
>        void *buf;
>        off_t offset;
>        unsigned data_length;
> @@ -568,8 +567,6 @@ static int push_cache_object(struct vnode_info *vnode_info, uint32_t vid,
>                return SD_RES_SUCCESS;
>        }
>
> -       memset(&fake_req, 0, sizeof(fake_req));
> -
>        first_bit = ffsll(bmap) - 1;
>        last_bit = fls64(bmap) - 1;
>
> @@ -595,20 +592,15 @@ static int push_cache_object(struct vnode_info *vnode_info, uint32_t vid,
>        if (ret != SD_RES_SUCCESS)
>                goto out;
>
> -       hdr->opcode = create ? SD_OP_CREATE_AND_WRITE_OBJ : SD_OP_WRITE_OBJ;
> -       hdr->flags = SD_FLAG_CMD_WRITE;
> -       hdr->data_length = data_length;
> -       hdr->epoch = sys_epoch();
> -
> -       hdr->obj.oid = oid;
> -       hdr->obj.offset = offset;
> -       hdr->obj.copies = sys->nr_copies;
> +       memset(&hdr, 0, sizeof(hdr));
> +       hdr.opcode = create ? SD_OP_CREATE_AND_WRITE_OBJ : SD_OP_WRITE_OBJ;
> +       hdr.flags = SD_FLAG_CMD_WRITE;
>
> -       fake_req.data = buf;
> -       fake_req.op = get_sd_op(hdr->opcode);
> -       fake_req.vnodes = vnode_info;
> +       hdr.obj.oid = oid;
> +       hdr.obj.offset = offset;
> +       hdr.obj.copies = sys->nr_copies;
>
> -       ret = forward_write_obj_req(&fake_req);
> +       ret = exec_local_req(&hdr, buf, data_length);
sys->outstanding_data_size would be updated in alloc_local_request()
which was called in exec_local_req(), this will be a race.

>        if (ret != SD_RES_SUCCESS)
>                eprintf("failed to push object %x\n", ret);
>
> --
> 1.7.10
>
> --
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> sheepdog at lists.wpkg.org
> http://lists.wpkg.org/mailman/listinfo/sheepdog



-- 
Yunkai Zhang
Work at Taobao