Revert "target: Fix VERIFY and WRITE VERIFY command parsing"

This reverts commit 3277f03749685b9ff33c9bebb4f80a598a6402c0

  Author: Bart Van Assche <bart.vanassche@sandisk.com>
  Date:   Thu Mar 30 10:12:39 2017 -0700

      target: Fix VERIFY and WRITE VERIFY command parsing

This patch broke existing behaviour for WRITE_VERIFY because
it dropped the original SCF_SCSI_DATA_CDB assignment for
bytchk = 0 so target_cmd_size_check() no longer rejected
this case, allowing an overflow case to trigger an OOPs
in iscsi-target.

Since the short term and long term fixes are still being
discussed, revert it for now since it's late in the merge
window and try again in v4.13-rc1.

Conflicts:
	drivers/target/target_core_sbc.c

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index a0ad618f1b1ada886058322a0224b26b0f74ccb0..4316f7b65fb7691fa38e81ce7ed4d4d62b9520df 100644 (file)
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -831,60 +831,6 @@ sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
        return 0;
 }
 
-/**
- * sbc_parse_verify - parse VERIFY, VERIFY_16 and WRITE VERIFY commands
- * @cmd:     (in)  structure that describes the SCSI command to be parsed.
- * @sectors: (out) Number of logical blocks on the storage medium that will be
- *           affected by the SCSI command.
- * @bufflen: (out) Expected length of the SCSI Data-Out buffer.
- */
-static sense_reason_t sbc_parse_verify(struct se_cmd *cmd, int *sectors,
-                                      u32 *bufflen)
-{
-       struct se_device *dev = cmd->se_dev;
-       u8 *cdb = cmd->t_task_cdb;
-       u8 bytchk = (cdb[1] >> 1) & 3;
-       sense_reason_t ret;
-
-       switch (cdb[0]) {
-       case VERIFY:
-       case WRITE_VERIFY:
-               *sectors = transport_get_sectors_10(cdb);
-               cmd->t_task_lba = transport_lba_32(cdb);
-               break;
-       case VERIFY_16:
-       case WRITE_VERIFY_16:
-               *sectors = transport_get_sectors_16(cdb);
-               cmd->t_task_lba = transport_lba_64(cdb);
-               break;
-       default:
-               WARN_ON_ONCE(true);
-               return TCM_UNSUPPORTED_SCSI_OPCODE;
-       }
-
-       if (sbc_check_dpofua(dev, cmd, cdb))
-               return TCM_INVALID_CDB_FIELD;
-
-       ret = sbc_check_prot(dev, cmd, cdb, *sectors, true);
-       if (ret)
-               return ret;
-
-       switch (bytchk) {
-       case 0:
-               *bufflen = 0;
-               break;
-       case 1:
-               *bufflen = sbc_get_size(cmd, *sectors);
-               cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
-               break;
-       default:
-               pr_err("Unsupported BYTCHK value %d for SCSI opcode %#x\n",
-                      bytchk, cdb[0]);
-               return TCM_INVALID_CDB_FIELD;
-       }
-       return TCM_NO_SENSE;
-}
-
 sense_reason_t
 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 {
@@ -952,6 +898,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                cmd->execute_cmd = sbc_execute_rw;
                break;
        case WRITE_10:
+       case WRITE_VERIFY:
                sectors = transport_get_sectors_10(cdb);
                cmd->t_task_lba = transport_lba_32(cdb);
 
@@ -965,13 +912,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
                cmd->execute_cmd = sbc_execute_rw;
                break;
-       case WRITE_VERIFY:
-       case WRITE_VERIFY_16:
-               ret = sbc_parse_verify(cmd, &sectors, &size);
-               if (ret)
-                       return ret;
-               cmd->execute_cmd = sbc_execute_rw;
-               goto check_lba;
        case WRITE_12:
                sectors = transport_get_sectors_12(cdb);
                cmd->t_task_lba = transport_lba_32(cdb);
@@ -987,6 +927,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                cmd->execute_cmd = sbc_execute_rw;
                break;
        case WRITE_16:
+       case WRITE_VERIFY_16:
                sectors = transport_get_sectors_16(cdb);
                cmd->t_task_lba = transport_lba_64(cdb);
 
@@ -1169,9 +1110,14 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                break;
        case VERIFY:
        case VERIFY_16:
-               ret = sbc_parse_verify(cmd, &sectors, &size);
-               if (ret)
-                       return ret;
+               size = 0;
+               if (cdb[0] == VERIFY) {
+                       sectors = transport_get_sectors_10(cdb);
+                       cmd->t_task_lba = transport_lba_32(cdb);
+               } else {
+                       sectors = transport_get_sectors_16(cdb);
+                       cmd->t_task_lba = transport_lba_64(cdb);
+               }
                cmd->execute_cmd = sbc_emulate_noop;
                goto check_lba;
        case REZERO_UNIT: