Patch "target/iscsi: Fix unsolicited data seq_end_offset calculation" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

target/iscsi: Fix unsolicited data seq_end_offset calculation

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
target-iscsi-fix-unsolicited-data-seq_end_offset-calculation.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Varun Prakash <[email protected]>
Date: Fri, 20 Jan 2017 16:44:33 +0530
Subject: target/iscsi: Fix unsolicited data seq_end_offset calculation

From: Varun Prakash <[email protected]>

[ Upstream commit 4d65491c269729a1e3b375c45e73213f49103d33 ]

In case of unsolicited data for the first sequence seq_end_offset must be set to minimum of total data length and FirstBurstLength, so do not add cmd->write_data_done to the min of total data length and FirstBurstLength.

This patch avoids that with ImmediateData=Yes, InitialR2T=No, MaxXmitDataSegmentLength < FirstBurstLength that a WRITE command with IO size above FirstBurstLength triggers sequence error messages, for example

Set following parameters on target (linux-4.8.12)
ImmediateData = Yes
InitialR2T = No
MaxXmitDataSegmentLength = 8k
FirstBurstLength = 64k

Log in from Open iSCSI initiator and execute
dd if=/dev/zero of=/dev/sdb bs=128k count=1 oflag=direct

Error messages on target
Command ITT: 0x00000035 with Offset: 65536, Length: 8192 outside of Sequence 73728:131072 while DataSequenceInOrder=Yes. Command ITT: 0x00000035, received DataSN: 0x00000001 higher than expected 0x00000000.
Unable to perform within-command recovery while ERL=0.

---
 drivers/target/iscsi/iscsi_target_erl0.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

@@ -44,10 +44,8 @@ void iscsit_set_dataout_sequence_values(
 	 */
 	if (cmd->unsolicited_data) {
 		cmd->seq_start_offset = cmd->write_data_done;
-		cmd->seq_end_offset = (cmd->write_data_done +
-			((cmd->se_cmd.data_length >
-			  conn->sess->sess_ops->FirstBurstLength) ?
-			 conn->sess->sess_ops->FirstBurstLength : cmd->se_cmd.data_length));
+		cmd->seq_end_offset = min(cmd->se_cmd.data_length,
+					conn->sess->sess_ops->FirstBurstLength);
 		return;
 	}
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/target-iscsi-fix-unsolicited-data-seq_end_offset-calculation.patch