[PATCH 5/7] iscsi-target: Fix iscsit_map_iovec cur_len + data_offset breakage

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch fixes two length + offset releated bugs in the new iscsit_map_iovec().
The first is where cur_len was being calculated incorrectly for the case type
SCF_SCSI_CONTROL_NONSG_IO_CDB with an sg->offset non zero offset.

The second adds the missing pg_off to kmap() when setting iov_base
from sg_page() with the current scatterlist pointer.

It also converts iscsit_map_iovec() to use sg_next() instead of
incremented the scatterlist pointer following lib/scatterlist.h

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/iscsi/iscsi_target.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 6ebc247..d84d52b 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -696,7 +696,7 @@ static int iscsit_map_iovec(
 	u32 data_offset,
 	u32 data_length)
 {
-	u32 i;
+	u32 i = 0;
 	struct scatterlist *sg;
 	unsigned int page_off;
 
@@ -705,20 +705,20 @@ static int iscsit_map_iovec(
 	 * At this point, we also know each contains a page.
 	 */
 	sg = &cmd->t_mem_sg[data_offset / PAGE_SIZE];
-	page_off = (data_offset % PAGE_SIZE) + sg->offset;
+	page_off = (data_offset % PAGE_SIZE);
 
 	cmd->first_data_sg = sg;
 	cmd->first_data_sg_off = page_off;
 
-	i = 0;
 	while (data_length) {
-		u32 cur_len = min_t(u32, data_length, (sg[i].length - page_off));
+		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
 
-		iov[i].iov_base = kmap(sg_page(&sg[i]));
+		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
 		iov[i].iov_len = cur_len;
 
 		data_length -= cur_len;
 		page_off = 0;
+		sg = sg_next(sg);
 		i++;
 	}
 
-- 
1.7.2.5