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author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2008-09-02 13:50:05 (GMT) |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2008-10-09 06:56:14 (GMT) |
commit | 626710c9d665ff381c7ec666b6a023f064ca5fef (patch) | |
tree | 011b7b58f3a5868439eab36fd3b3e90952ccbef0 /drivers/scsi/sg.c | |
parent | 44c7b0eaa041007066e30ab4869d5bbf8dad5989 (diff) | |
download | linux-626710c9d665ff381c7ec666b6a023f064ca5fef.tar.xz |
sg: incorporate sg_build_direct into sg_start_req
Calling blk_rq_map_user() at a single place is better than at
different two places. It makes the code more understandable.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/scsi/sg.c')
-rw-r--r-- | drivers/scsi/sg.c | 80 |
1 files changed, 33 insertions, 47 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 9a56c0d..c0b6866 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -202,7 +202,6 @@ static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id); static Sg_request *sg_add_request(Sg_fd * sfp); static int sg_remove_request(Sg_fd * sfp, Sg_request * srp); static int sg_res_in_use(Sg_fd * sfp); -static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len); static Sg_device *sg_get_dev(int dev); #ifdef CONFIG_SCSI_PROC_FS static int sg_last_dev(void); @@ -1628,16 +1627,17 @@ exit_sg(void) static int sg_start_req(Sg_request *srp, unsigned char *cmd) { - int res = 0; + int res; struct request *rq; Sg_fd *sfp = srp->parentfp; sg_io_hdr_t *hp = &srp->header; int dxfer_len = (int) hp->dxfer_len; int dxfer_dir = hp->dxfer_direction; + unsigned int iov_count = hp->iovec_count; Sg_scatter_hold *req_schp = &srp->data; Sg_scatter_hold *rsv_schp = &sfp->reserve; struct request_queue *q = sfp->parentdp->device->request_queue; - struct rq_map_data map_data; + struct rq_map_data *md, map_data; int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ; SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n", @@ -1660,38 +1660,43 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd) if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE)) return 0; - if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) && - (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) && - (!sfp->parentdp->device->host->unchecked_isa_dma) && + if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO && + dxfer_dir != SG_DXFER_UNKNOWN && !iov_count && + !sfp->parentdp->device->host->unchecked_isa_dma && blk_rq_aligned(q, hp->dxferp, dxfer_len)) - return sg_build_direct(srp, sfp, dxfer_len); + md = NULL; + else + md = &map_data; + + if (md) { + if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen) + sg_link_reserve(sfp, srp, dxfer_len); + else { + res = sg_build_indirect(req_schp, sfp, dxfer_len); + if (res) + return res; + } - if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen)) - sg_link_reserve(sfp, srp, dxfer_len); + md->pages = req_schp->pages; + md->page_order = req_schp->page_order; + md->nr_entries = req_schp->k_use_sg; + } + + if (iov_count) + res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count, + hp->dxfer_len, GFP_ATOMIC); else - res = sg_build_indirect(req_schp, sfp, dxfer_len); + res = blk_rq_map_user(q, rq, md, hp->dxferp, + hp->dxfer_len, GFP_ATOMIC); if (!res) { - struct request *rq = srp->rq; - Sg_scatter_hold *schp = &srp->data; - int iovec_count = (int) hp->iovec_count; - - map_data.pages = schp->pages; - map_data.page_order = schp->page_order; - map_data.nr_entries = schp->k_use_sg; - - if (iovec_count) - res = blk_rq_map_user_iov(q, rq, &map_data, hp->dxferp, - iovec_count, - hp->dxfer_len, GFP_ATOMIC); - else - res = blk_rq_map_user(q, rq, &map_data, hp->dxferp, - hp->dxfer_len, GFP_ATOMIC); + srp->bio = rq->bio; - if (!res) - srp->bio = rq->bio; + if (!md) { + req_schp->dio_in_use = 1; + hp->info |= SG_INFO_DIRECT_IO; + } } - return res; } @@ -1730,25 +1735,6 @@ sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize) return tablesize; /* number of scat_gath elements allocated */ } -/* Returns: -ve -> error, 0 -> done, 1 -> try indirect */ -static int -sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len) -{ - sg_io_hdr_t *hp = &srp->header; - Sg_scatter_hold *schp = &srp->data; - int res; - struct request *rq = srp->rq; - struct request_queue *q = sfp->parentdp->device->request_queue; - - res = blk_rq_map_user(q, rq, NULL, hp->dxferp, dxfer_len, GFP_ATOMIC); - if (res) - return res; - srp->bio = rq->bio; - schp->dio_in_use = 1; - hp->info |= SG_INFO_DIRECT_IO; - return 0; -} - static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size) { |