target: Fix quiese during transport_write_pending_qf endless loop

This patch fixes a potential end-less loop during QUEUE_FULL,
where cmd->se_tfo->write_pending() callback fails repeatedly
but __transport_wait_for_tasks() has already been invoked to
quiese the outstanding se_cmd descriptor.

To address this bug, this patch adds a CMD_T_STOP|CMD_T_ABORTED
check within transport_write_pending_qf() and invokes the
existing se_cmd->t_transport_stop_comp to signal quiese
completion back to __transport_wait_for_tasks().

Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Cc: Potnuri Bharat Teja <bharat@chelsio.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: stable@vger.kernel.org # 4.11+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger 2017-09-29 16:43:11 -07:00
parent fd2f928b0d
commit 9574a497df

View File

@ -2560,7 +2560,20 @@ EXPORT_SYMBOL(transport_generic_new_cmd);
static void transport_write_pending_qf(struct se_cmd *cmd)
{
unsigned long flags;
int ret;
bool stop;
spin_lock_irqsave(&cmd->t_state_lock, flags);
stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
if (stop) {
pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
__func__, __LINE__, cmd->tag);
complete_all(&cmd->t_transport_stop_comp);
return;
}
ret = cmd->se_tfo->write_pending(cmd);
if (ret) {