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-rw-r--r--drivers/scsi/osd/osd_initiator.c71
-rw-r--r--include/scsi/osd_initiator.h7
2 files changed, 78 insertions, 0 deletions
diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index f5b5735f76d5..0433ea6f27c9 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 169a5dcda096..53a9e886612b 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
*/