[ 26/36] iscsi-target: Fix ImmediateData=Yes failure regression in >= v3.10

From: Greg Kroah-Hartman
Date: Thu Sep 05 2013 - 16:39:04 EST


3.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

commit 9d86a2befceb06ee83c1a588915e6d6e0abef797 upstream.

This patch addresses a regression bug within ImmediateData=Yes failure
handling that ends up triggering an OOPs within >= v3.10 iscsi-target
code.

The problem occurs when iscsit_process_scsi_cmd() does the call to
target_put_sess_cmd(), and once again in iscsit_get_immediate_data()
that is triggered during two different cases:

- When iscsit_sequence_cmd() returns CMDSN_LOWER_THAN_EXP, for which
the descriptor state will already have been set to ISTATE_REMOVE
by iscsit_sequence_cmd(), and
- When iscsi_cmd->sense_reason is set, for which iscsit_execute_cmd()
will have already called transport_send_check_condition_and_sense()
to queue the exception response.

It changes iscsit_process_scsi_cmd() to drop the early call, and makes
iscsit_get_immediate_data() call target_put_sess_cmd() from a single
location after dumping the immediate data for the failed command.

The regression was initially introduced in commit:

commit 561bf15892375597ee59d473a704a3e634c4f311
Author: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Date: Wed Jul 3 03:58:58 2013 -0700

iscsi-target: Fix iscsit_sequence_cmd reject handling for iser

Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/target/iscsi/iscsi_target.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)

--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1086,7 +1086,6 @@ int iscsit_process_scsi_cmd(struct iscsi
if (cmd->reject_reason)
return 0;

- target_put_sess_cmd(conn->sess->se_sess, &cmd->se_cmd);
return 1;
}
/*
@@ -1124,14 +1123,10 @@ after_immediate_data:
*/
cmdsn_ret = iscsit_sequence_cmd(cmd->conn, cmd,
(unsigned char *)hdr, hdr->cmdsn);
- if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER) {
+ if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
return -1;
- } else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
- target_put_sess_cmd(conn->sess->se_sess, &cmd->se_cmd);
- return 0;
- }

- if (cmd->sense_reason) {
+ if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
int rc;

rc = iscsit_dump_data_payload(cmd->conn,


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