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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-09-02 17:50:05 +0400
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 10:56:14 +0400
commit626710c9d665ff381c7ec666b6a023f064ca5fef (patch)
tree011b7b58f3a5868439eab36fd3b3e90952ccbef0 /drivers/scsi/sg.c
parent44c7b0eaa041007066e30ab4869d5bbf8dad5989 (diff)
downloadlinux-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.c80
1 files changed, 33 insertions, 47 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 9a56c0d320bf..c0b6866eece9 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)
{