SPC5r17 states that the contents of the ADDITIONAL LENGTH field are not
altered based on the allocation length, so always calculate and pack the
full key list length even if the list itself is truncated.
According to Maged:
Yes it fixes the "Storage Spaces Persistent Reservation" test in the
Windows 2016 Server Failover Cluster validation suites when having
many connections that result in more than 8 registrations. I tested
your patch on 4.17 with iblock.
This behaviour can be tested using the libiscsi PrinReadKeys.Truncate
test.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
Reviewed-by: Mike Christie <mchristi@xxxxxxxxxx>
Tested-by: Maged Mokhtar <mmokhtar@xxxxxxxxxxx>
---
drivers/target/target_core_pr.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
Changes since v1:
* CC stable
* mention Maged's Windows PR test fix comment in commit message
* add Reviewed-by and Tested-by tags
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 01ac306131c1..2e865fdaa362 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -3727,11 +3727,16 @@ core_scsi3_pri_read_keys(struct se_cmd *cmd)
* Check for overflow of 8byte PRI READ_KEYS payload and
* next reservation key list descriptor.
*/
- if ((add_len + 8) > (cmd->data_length - 8))
- break;
-
- put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
- off += 8;
+ if ((off + 8) <= cmd->data_length) {
+ put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
+ off += 8;
+ }
+ /*
+ * SPC5r17: 6.16.2 READ KEYS service action
+ * The ADDITIONAL LENGTH field indicates the number of bytes in
+ * the Reservation key list. The contents of the ADDITIONAL
+ * LENGTH field are not altered based on the allocation length
+ */
add_len += 8;
}
spin_unlock(&dev->t10_pr.registration_lock);
--
2.13.6
