Commit c130480b authored Aug 31, 2013 by Nicholas Bellinger

target: Fix se_cmd->state_list leak regression during WRITE failure



This patch addresses a v3.11 specific regression where se_cmd->state_list
was being leaked during a fabric WRITE failure, when the fabric releases
an associated se_cmd descriptor before I/O submission occurs, and normal
fast path callbacks have a chance to call target_remove_from_state_list().

It was manifesting with Poison overwritten messages with iscsi-target
once an ImmediateData payload CRC32C failure occured.

This bug was originally introduced during v3.11-rc1 with the following
commit:

commit 0b66818a
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date:   Thu Jun 6 01:36:41 2013 -0700

    target: Drop unnecessary CMD_T_DEV_ACTIVE check from transport_lun_remove_cmd

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

parent 28aaa950

drivers/target/target_core_transport.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -2134,6 +2134,7 @@ static void transport_write_pending_qf(struct se_cmd *cmd)

		int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
		{
		unsigned long flags;
		int ret = 0;

		if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
		@@ -2144,6 +2145,16 @@ int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
		} else {
		if (wait_for_tasks)
		transport_wait_for_tasks(cmd);
		/*
		* Handle WRITE failure case where transport_generic_new_cmd()
		* has already added se_cmd to state_list, but fabric has
		* failed command before I/O submission.
		*/
		if (cmd->state_active) {
		spin_lock_irqsave(&cmd->t_state_lock, flags);
		target_remove_from_state_list(cmd);
		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
		}

		if (cmd->se_lun)
		transport_lun_remove_cmd(cmd);