Target/sbc: Fix protection copy routine

Need to take into account that protection sg_list
(copy-buffer) may consist of multiple entries.

Changes from v0:
- Changed commit description

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index fa3cae393e13..a4489444ffbc 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -1074,12 +1074,19 @@ sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
         struct scatterlist *psg;
         void *paddr, *addr;
         unsigned int i, len, left;
+        unsigned int offset = 0;
 
         left = sectors * dev->prot_length;
 
         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
 
                 len = min(psg->length, left);
+                if (offset >= sg->length) {
+                        sg = sg_next(sg);
+                        offset = 0;
+                        sg_off = sg->offset;
+                }
+
                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
                 addr = kmap_atomic(sg_page(sg)) + sg_off;
 
@@ -1089,6 +1096,7 @@ sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
                         memcpy(addr, paddr, len);
 
                 left -= len;
+                offset += len;
                 kunmap_atomic(paddr);
                 kunmap_atomic(addr);
         }