Boaz Harrosh wrote:
> James Bottomley wrote:
>> On Tue, 2009-02-10 at 17:43 +0000, James Bottomley wrote:
>>> There's a current barrier to this: osd_initiator has also become a
>>> consumer of blk_rq_append_bio().
>>>
>>> It seems to be emulating block internals, so I think the fix is twofold:
>>>
>>> 1. adjust blk_rq_map_kern to call blk_rq_append_bio() instead of
>>> blk_rq_prep_bio() (with an extra failure path).
>>> 2. make osd_initiator simply call it for additions.
>>>
>>> I can code up a patch to see if it works.
>> So this is the patch to allow blk_rq_map_kern to append to requests,
>> which is what I think is needed.
>>
>> Unfortunately unwinding osd_initator's bio dependence and putting it
>> back on data buffers looks to be a bit of a longer chore.
>>
>> James
>>
>> ---
>>
>> diff --git a/block/blk-map.c b/block/blk-map.c
>> index 25d15ff..1a1e26d 100644
>> --- a/block/blk-map.c
>> +++ b/block/blk-map.c
>> @@ -289,6 +289,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
>> int reading = rq_data_dir(rq) == READ;
>> int do_copy = 0;
>> struct bio *bio;
>> + int ret;
>>
>> if (len > (q->max_hw_sectors << 9))
>> return -EINVAL;
>> @@ -310,7 +311,13 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
>> if (do_copy)
>> rq->cmd_flags |= REQ_COPY_USER;
>>
>> - blk_rq_bio_prep(q, rq, bio);
>> + ret = blk_rq_append_bio(q, rq, bio);
>> + if (unlikely(ret)) {
>> + /* request is too big */
>> + bio_put(bio);
>> + return ret;
>> + }
>> +
>> blk_queue_bounce(q, &rq->bio);
>> rq->buffer = rq->data = NULL;
>> return 0;
>>
>>
>
> This works, with your patch and below code
> I'm passing my tests. I would say it is pretty safe too,
> since blk_rq_bio_prep would leak the bio if it was called
> twice on same request, before.
>
> Thanks, I'll send a proper patch after some more testing.
>
> ---
> git diff --stat -p
> drivers/scsi/osd/osd_initiator.c | 12 +++---------
> 1 files changed, 3 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
> index 1696130..9cfdce4 100644
> --- a/drivers/scsi/osd/osd_initiator.c
> +++ b/drivers/scsi/osd/osd_initiator.c
> @@ -824,18 +824,12 @@ EXPORT_SYMBOL(osd_req_add_set_attr_list);
> static int _append_map_kern(struct request *req,
> void *buff, unsigned len, gfp_t flags)
> {
> - struct bio *bio;
> int ret;
>
> - bio = bio_map_kern(req->q, buff, len, flags);
> - if (IS_ERR(bio)) {
> - OSD_ERR("Failed bio_map_kern(%p, %d) => %ld\n", buff, len,
> - PTR_ERR(bio));
> - return PTR_ERR(bio);
> - }
> - ret = blk_rq_append_bio(req->q, req, bio);
> + ret = blk_rq_map_kern(req->q, req, buff, len, flags);
> if (ret) {
> - OSD_ERR("Failed blk_rq_append_bio(%p) => %d\n", bio, ret);
> + OSD_DEBUG("Failed blk_rq_map_kern(%p, %u) => %d\n",
> + buff, len, ret);
> bio_put(bio);
- bio_put(bio);
Sorry
> }
> return ret;
>
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