Re: [PATCH 17/17] blk-map/bio: remove superflous @q from blk_rq_map_{user|kern}*()

From: Boaz Harrosh
Date: Wed Apr 01 2009 - 13:07:30 EST


On 04/01/2009 04:44 PM, Tejun Heo wrote:
> Impact: API cleanup
>
> All initialized requests must and are guaranteed to have rq->q set.
> Taking both @q and @rq parameters doesn't improve anything. It only
> adds pathological corner case where @q != !@rq->q. Kill the
> superflous @q parameter from blk_rq_map_{user|kern}*().
>
> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>

Thank god, great stuff

> ---
> block/blk-map.c | 27 +++++++++++----------------
> block/bsg.c | 5 ++---
> block/scsi_ioctl.c | 6 +++---
> drivers/block/pktcdvd.c | 2 +-
> drivers/cdrom/cdrom.c | 2 +-
> drivers/scsi/device_handler/scsi_dh_alua.c | 2 +-
> drivers/scsi/device_handler/scsi_dh_emc.c | 2 +-
> drivers/scsi/device_handler/scsi_dh_rdac.c | 2 +-
> drivers/scsi/scsi_lib.c | 7 +++----
> drivers/scsi/scsi_tgt_lib.c | 3 +--
> drivers/scsi/sg.c | 6 +++---
> drivers/scsi/st.c | 3 +--
> include/linux/blkdev.h | 15 +++++++--------
> 13 files changed, 36 insertions(+), 46 deletions(-)
>
> diff --git a/block/blk-map.c b/block/blk-map.c
> index f60f439..885d359 100644
> --- a/block/blk-map.c
> +++ b/block/blk-map.c
> @@ -10,7 +10,6 @@
>
> /**
> * blk_rq_map_user_iov - map user data to a request, for REQ_TYPE_BLOCK_PC usage
> - * @q: request queue where request should be inserted
> * @rq: request to map data to
> * @md: pointer to the rq_map_data holding pages (if necessary)
> * @iov: pointer to the iovec
> @@ -30,10 +29,10 @@
> * original bio must be passed back in to blk_rq_unmap_user() for proper
> * unmapping.
> */
> -int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
> - struct rq_map_data *md, struct iovec *iov, int count,
> - gfp_t gfp)
> +int blk_rq_map_user_iov(struct request *rq, struct rq_map_data *md,
> + struct iovec *iov, int count, gfp_t gfp)
> {
> + struct request_queue *q = rq->q;
> struct bio *bio = ERR_PTR(-EINVAL);
> int rw = rq_data_dir(rq);
>
> @@ -66,7 +65,6 @@ EXPORT_SYMBOL(blk_rq_map_user_iov);
>
> /**
> * blk_rq_map_user - map user data to a request, for REQ_TYPE_BLOCK_PC usage
> - * @q: request queue where request should be inserted
> * @rq: request structure to fill
> * @md: pointer to the rq_map_data holding pages (if necessary)
> * @ubuf: the user buffer
> @@ -86,16 +84,15 @@ EXPORT_SYMBOL(blk_rq_map_user_iov);
> * original bio must be passed back in to blk_rq_unmap_user() for proper
> * unmapping.
> */
> -int blk_rq_map_user(struct request_queue *q, struct request *rq,
> - struct rq_map_data *md, void __user *ubuf,
> - unsigned long len, gfp_t gfp)
> +int blk_rq_map_user(struct request *rq, struct rq_map_data *md,
> + void __user *ubuf, unsigned long len, gfp_t gfp)
> {
> struct iovec iov;
>
> iov.iov_base = ubuf;
> iov.iov_len = len;
>
> - return blk_rq_map_user_iov(q, rq, md, &iov, 1, gfp);
> + return blk_rq_map_user_iov(rq, md, &iov, 1, gfp);
> }
> EXPORT_SYMBOL(blk_rq_map_user);
>
> @@ -128,7 +125,6 @@ EXPORT_SYMBOL(blk_rq_unmap_user);
>
> /**
> * blk_rq_map_kern_sg - map kernel data to a request, for REQ_TYPE_BLOCK_PC
> - * @q: request queue where request should be inserted
> * @rq: request to fill
> * @sgl: area to map
> * @nents: number of elements in @sgl
> @@ -138,9 +134,10 @@ EXPORT_SYMBOL(blk_rq_unmap_user);
> * Data will be mapped directly if possible. Otherwise a bounce
> * buffer is used.
> */
> -int blk_rq_map_kern_sg(struct request_queue *q, struct request *rq,
> - struct scatterlist *sgl, int nents, gfp_t gfp)
> +int blk_rq_map_kern_sg(struct request *rq, struct scatterlist *sgl, int nents,
> + gfp_t gfp)
> {
> + struct request_queue *q = rq->q;
> int rw = rq_data_dir(rq);
> struct bio *bio;
>
> @@ -165,7 +162,6 @@ EXPORT_SYMBOL(blk_rq_map_kern_sg);
>
> /**
> * blk_rq_map_kern - map kernel data to a request, for REQ_TYPE_BLOCK_PC usage
> - * @q: request queue where request should be inserted
> * @rq: request to fill
> * @kbuf: the kernel buffer
> * @len: length of user data
> @@ -175,13 +171,12 @@ EXPORT_SYMBOL(blk_rq_map_kern_sg);
> * Data will be mapped directly if possible. Otherwise a bounce
> * buffer is used.
> */
> -int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
> - unsigned int len, gfp_t gfp)
> +int blk_rq_map_kern(struct request *rq, void *kbuf, unsigned int len, gfp_t gfp)
> {
> struct scatterlist sg;
>
> sg_init_one(&sg, kbuf, len);
>
> - return blk_rq_map_kern_sg(q, rq, &sg, 1, gfp);
> + return blk_rq_map_kern_sg(rq, &sg, 1, gfp);
> }
> EXPORT_SYMBOL(blk_rq_map_kern);
> diff --git a/block/bsg.c b/block/bsg.c
> index 206060e..69c222a 100644
> --- a/block/bsg.c
> +++ b/block/bsg.c
> @@ -283,7 +283,7 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
> next_rq->cmd_type = rq->cmd_type;
>
> dxferp = (void*)(unsigned long)hdr->din_xferp;
> - ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
> + ret = blk_rq_map_user(next_rq, NULL, dxferp,
> hdr->din_xfer_len, GFP_KERNEL);
> if (ret)
> goto out;
> @@ -299,8 +299,7 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
> dxfer_len = 0;
>
> if (dxfer_len) {
> - ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
> - GFP_KERNEL);
> + ret = blk_rq_map_user(rq, NULL, dxferp, dxfer_len, GFP_KERNEL);
> if (ret)
> goto out;
> }
> diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
> index fd538f8..a98e4ec 100644
> --- a/block/scsi_ioctl.c
> +++ b/block/scsi_ioctl.c
> @@ -306,11 +306,11 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
> hdr->iovec_count = iov_shorten(iov, hdr->iovec_count,
> hdr->dxfer_len);
>
> - ret = blk_rq_map_user_iov(q, rq, NULL, iov, hdr->iovec_count,
> + ret = blk_rq_map_user_iov(rq, NULL, iov, hdr->iovec_count,
> GFP_KERNEL);
> kfree(iov);
> } else if (hdr->dxfer_len)
> - ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
> + ret = blk_rq_map_user(rq, NULL, hdr->dxferp, hdr->dxfer_len,
> GFP_KERNEL);
>
> if (ret)
> @@ -449,7 +449,7 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
> break;
> }
>
> - if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_WAIT)) {
> + if (bytes && blk_rq_map_kern(rq, buffer, bytes, __GFP_WAIT)) {
> err = DRIVER_ERROR << 24;
> goto out;
> }
> diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
> index dc7a8c3..a4e5e9b 100644
> --- a/drivers/block/pktcdvd.c
> +++ b/drivers/block/pktcdvd.c
> @@ -771,7 +771,7 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
> WRITE : READ, __GFP_WAIT);
>
> if (cgc->buflen) {
> - if (blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, __GFP_WAIT))
> + if (blk_rq_map_kern(rq, cgc->buffer, cgc->buflen, __GFP_WAIT))
> goto out;
> }
>
> diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
> index cceace6..ef67aec 100644
> --- a/drivers/cdrom/cdrom.c
> +++ b/drivers/cdrom/cdrom.c
> @@ -2112,7 +2112,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
> break;
> }
>
> - ret = blk_rq_map_user(q, rq, NULL, ubuf, len, GFP_KERNEL);
> + ret = blk_rq_map_user(rq, NULL, ubuf, len, GFP_KERNEL);
> if (ret) {
> blk_put_request(rq);
> break;
> diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
> index e356b43..f3cb900 100644
> --- a/drivers/scsi/device_handler/scsi_dh_alua.c
> +++ b/drivers/scsi/device_handler/scsi_dh_alua.c
> @@ -101,7 +101,7 @@ static struct request *get_alua_req(struct scsi_device *sdev,
> return NULL;
> }
>
> - if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
> + if (buflen && blk_rq_map_kern(rq, buffer, buflen, GFP_NOIO)) {
> blk_put_request(rq);
> sdev_printk(KERN_INFO, sdev,
> "%s: blk_rq_map_kern failed\n", __func__);
> diff --git a/drivers/scsi/device_handler/scsi_dh_emc.c b/drivers/scsi/device_handler/scsi_dh_emc.c
> index 0e572d2..dbbd56d 100644
> --- a/drivers/scsi/device_handler/scsi_dh_emc.c
> +++ b/drivers/scsi/device_handler/scsi_dh_emc.c
> @@ -308,7 +308,7 @@ static struct request *get_req(struct scsi_device *sdev, int cmd,
> rq->timeout = CLARIION_TIMEOUT;
> rq->retries = CLARIION_RETRIES;
>
> - if (blk_rq_map_kern(rq->q, rq, buffer, len, GFP_NOIO)) {
> + if (blk_rq_map_kern(rq, buffer, len, GFP_NOIO)) {
> blk_put_request(rq);
> return NULL;
> }
> diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
> index 5366476..f50b33a 100644
> --- a/drivers/scsi/device_handler/scsi_dh_rdac.c
> +++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
> @@ -219,7 +219,7 @@ static struct request *get_rdac_req(struct scsi_device *sdev,
> return NULL;
> }
>
> - if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
> + if (buflen && blk_rq_map_kern(rq, buffer, buflen, GFP_NOIO)) {
> blk_put_request(rq);
> sdev_printk(KERN_INFO, sdev,
> "get_rdac_req: blk_rq_map_kern failed.\n");
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 3fa5589..66c3d0b 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -216,8 +216,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
>
> req = blk_get_request(sdev->request_queue, write, __GFP_WAIT);
>
> - if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
> - buffer, bufflen, __GFP_WAIT))
> + if (bufflen && blk_rq_map_kern(req, buffer, bufflen, __GFP_WAIT))
> goto out;
>
> req->cmd_len = COMMAND_SIZE(cmd[0]);
> @@ -332,9 +331,9 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
> req->cmd_flags |= REQ_QUIET;
>
> if (use_sg)
> - err = blk_rq_map_kern_sg(req->q, req, buffer, use_sg, gfp);
> + err = blk_rq_map_kern_sg(req, buffer, use_sg, gfp);
> else if (bufflen)
> - err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp);
> + err = blk_rq_map_kern(req, buffer, bufflen, gfp);
>
> if (err)
> goto free_req;
> diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
> index 48ba413..55beba4 100644
> --- a/drivers/scsi/scsi_tgt_lib.c
> +++ b/drivers/scsi/scsi_tgt_lib.c
> @@ -357,12 +357,11 @@ static int scsi_tgt_transfer_response(struct scsi_cmnd *cmd)
> static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,
> unsigned long uaddr, unsigned int len, int rw)
> {
> - struct request_queue *q = cmd->request->q;
> struct request *rq = cmd->request;
> int err;
>
> dprintk("%lx %u\n", uaddr, len);
> - err = blk_rq_map_user(q, rq, NULL, (void *)uaddr, len, GFP_KERNEL);
> + err = blk_rq_map_user(rq, NULL, (void *)uaddr, len, GFP_KERNEL);
> if (err) {
> /*
> * TODO: need to fixup sg_tablesize, max_segment_size,
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 5fcf436..a769041 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -1672,11 +1672,11 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd)
> }
>
> if (iov_count)
> - res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count,
> + res = blk_rq_map_user_iov(rq, md, hp->dxferp, iov_count,
> GFP_ATOMIC);
> else
> - res = blk_rq_map_user(q, rq, md, hp->dxferp,
> - hp->dxfer_len, GFP_ATOMIC);
> + res = blk_rq_map_user(rq, md, hp->dxferp, hp->dxfer_len,
> + GFP_ATOMIC);
>
> if (!res) {
> srp->bio = rq->bio;
> diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
> index c6f19ee..c4615bb 100644
> --- a/drivers/scsi/st.c
> +++ b/drivers/scsi/st.c
> @@ -492,8 +492,7 @@ static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
> mdata->null_mapped = 1;
>
> if (bufflen) {
> - err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
> - GFP_KERNEL);
> + err = blk_rq_map_user(req, mdata, NULL, bufflen, GFP_KERNEL);
> if (err) {
> blk_put_request(req);
> return DRIVER_ERROR << 24;
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 6876466..ff0ad9e 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -770,15 +770,14 @@ extern void __blk_stop_queue(struct request_queue *q);
> extern void __blk_run_queue(struct request_queue *);
> extern void blk_run_queue(struct request_queue *);
> extern void blk_start_queueing(struct request_queue *);
> -extern int blk_rq_map_user(struct request_queue *, struct request *,
> - struct rq_map_data *, void __user *, unsigned long,
> - gfp_t);
> +extern int blk_rq_map_user(struct request *rq, struct rq_map_data *md,
> + void __user *ubuf, unsigned long len, gfp_t gfp);
> extern int blk_rq_unmap_user(struct bio *);
> -extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
> -extern int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
> - struct rq_map_data *md, struct iovec *iov,
> - int count, gfp_t gfp);
> -extern int blk_rq_map_kern_sg(struct request_queue *q, struct request *rq,
> +extern int blk_rq_map_kern(struct request *rq, void *kbuf, unsigned int len,
> + gfp_t gfp);
> +extern int blk_rq_map_user_iov(struct request *rq, struct rq_map_data *md,
> + struct iovec *iov, int count, gfp_t gfp);
> +extern int blk_rq_map_kern_sg(struct request *rq,
> struct scatterlist *sgl, int nents, gfp_t gfp);
> extern int blk_execute_rq(struct request_queue *, struct gendisk *,
> struct request *, int);

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