diff options
| -rw-r--r-- | drivers/scsi/osd/osd_initiator.c | 71 | ||||
| -rw-r--r-- | include/scsi/osd_initiator.h | 7 |
2 files changed, 78 insertions, 0 deletions
diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c index f5b5735f76d..0433ea6f27c 100644 --- a/drivers/scsi/osd/osd_initiator.c +++ b/drivers/scsi/osd/osd_initiator.c @@ -1015,6 +1015,77 @@ int osd_req_read_sg(struct osd_request *or, } EXPORT_SYMBOL(osd_req_read_sg); +/* SG-list write/read Kern API + * + * osd_req_{write,read}_sg_kern takes an array of @buff pointers and an array + * of sg_entries. @numentries indicates how many pointers and sg_entries there + * are. By requiring an array of buff pointers. This allows a caller to do a + * single write/read and scatter into multiple buffers. + * NOTE: Each buffer + len should not cross a page boundary. + */ +static struct bio *_create_sg_bios(struct osd_request *or, + void **buff, const struct osd_sg_entry *sglist, unsigned numentries) +{ + struct request_queue *q = osd_request_queue(or->osd_dev); + struct bio *bio; + unsigned i; + + bio = bio_kmalloc(GFP_KERNEL, numentries); + if (unlikely(!bio)) { + OSD_DEBUG("Faild to allocate BIO size=%u\n", numentries); + return ERR_PTR(-ENOMEM); + } + + for (i = 0; i < numentries; i++) { + unsigned offset = offset_in_page(buff[i]); + struct page *page = virt_to_page(buff[i]); + unsigned len = sglist[i].len; + unsigned added_len; + + BUG_ON(offset + len > PAGE_SIZE); + added_len = bio_add_pc_page(q, bio, page, len, offset); + if (unlikely(len != added_len)) { + OSD_DEBUG("bio_add_pc_page len(%d) != added_len(%d)\n", + len, added_len); + bio_put(bio); + return ERR_PTR(-ENOMEM); + } + } + + return bio; +} + +int osd_req_write_sg_kern(struct osd_request *or, + const struct osd_obj_id *obj, void **buff, + const struct osd_sg_entry *sglist, unsigned numentries) +{ + struct bio *bio = _create_sg_bios(or, buff, sglist, numentries); + if (IS_ERR(bio)) + return PTR_ERR(bio); + + bio->bi_rw |= REQ_WRITE; + osd_req_write_sg(or, obj, bio, sglist, numentries); + + return 0; +} +EXPORT_SYMBOL(osd_req_write_sg_kern); + +int osd_req_read_sg_kern(struct osd_request *or, + const struct osd_obj_id *obj, void **buff, + const struct osd_sg_entry *sglist, unsigned numentries) +{ + struct bio *bio = _create_sg_bios(or, buff, sglist, numentries); + if (IS_ERR(bio)) + return PTR_ERR(bio); + + osd_req_read_sg(or, obj, bio, sglist, numentries); + + return 0; +} +EXPORT_SYMBOL(osd_req_read_sg_kern); + + + void osd_req_get_attributes(struct osd_request *or, const struct osd_obj_id *obj) { diff --git a/include/scsi/osd_initiator.h b/include/scsi/osd_initiator.h index 169a5dcda09..53a9e886612 100644 --- a/include/scsi/osd_initiator.h +++ b/include/scsi/osd_initiator.h @@ -455,6 +455,13 @@ int osd_req_write_sg(struct osd_request *or, int osd_req_read_sg(struct osd_request *or, const struct osd_obj_id *obj, struct bio *bio, const struct osd_sg_entry *sglist, unsigned numentries); +int osd_req_write_sg_kern(struct osd_request *or, + const struct osd_obj_id *obj, void **buff, + const struct osd_sg_entry *sglist, unsigned numentries); +int osd_req_read_sg_kern(struct osd_request *or, + const struct osd_obj_id *obj, void **buff, + const struct osd_sg_entry *sglist, unsigned numentries); + /* * Root/Partition/Collection/Object Attributes commands */ |