From 9574a497df2bbc0a676b609ce0dd24d237cee3a6 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Fri, 29 Sep 2017 16:43:11 -0700 Subject: [PATCH] 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 Cc: Hannes Reinecke Cc: Bryant G. Ly Cc: Michael Cyr Cc: Potnuri Bharat Teja Cc: Sagi Grimberg Cc: stable@vger.kernel.org # 4.11+ Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index d02218c71dd6..0e89db84b200 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -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) { -- 2.30.2