This is a note to let you know that I've just added the patch titled target: Fix missing complete during ABORT_TASK + CMD_T_FABRIC_STOP to the 4.7-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-fix-missing-complete-during-abort_task-cmd_t_fabric_stop.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5e2c956b8aa24d4f33ff7afef92d409eed164746 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> Date: Wed, 25 May 2016 12:25:04 -0700 Subject: target: Fix missing complete during ABORT_TASK + CMD_T_FABRIC_STOP From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> commit 5e2c956b8aa24d4f33ff7afef92d409eed164746 upstream. During transport_generic_free_cmd() with a concurrent TMR ABORT_TASK and shutdown CMD_T_FABRIC_STOP bit set, the caller will be blocked on se_cmd->cmd_wait_stop completion until the final kref_put() -> target_release_cmd_kref() has been invoked to call complete(). However, when ABORT_TASK is completed with FUNCTION_COMPLETE in core_tmr_abort_task(), the aborted se_cmd will have already been removed from se_sess->sess_cmd_list via list_del_init(). This results in target_release_cmd_kref() hitting the legacy list_empty() == true check, invoking ->release_cmd() but skipping complete() to wakeup se_cmd->cmd_wait_stop blocked earlier in transport_generic_free_cmd() code. To address this bug, it's safe to go ahead and drop the original list_empty() check so that fabric_stop invokes the complete() as expected, since list_del_init() can safely be used on a empty list. Cc: Mike Christie <mchristi@xxxxxxxxxx> Cc: Quinn Tran <quinn.tran@xxxxxxxxxx> Cc: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Hannes Reinecke <hare@xxxxxxx> Tested-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/target/target_core_transport.c | 6 ------ 1 file changed, 6 deletions(-) --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2565,12 +2565,6 @@ static void target_release_cmd_kref(stru bool fabric_stop; spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); - if (list_empty(&se_cmd->se_cmd_list)) { - spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); - target_free_cmd_mem(se_cmd); - se_cmd->se_tfo->release_cmd(se_cmd); - return; - } spin_lock(&se_cmd->t_state_lock); fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP); Patches currently in stable-queue which might be from nab@xxxxxxxxxxxxxxx are queue-4.7/target-fix-max_unmap_lba_count-calc-overflow.patch queue-4.7/target-fix-ordered-task-check_condition-early-exception-handling.patch queue-4.7/ib-core-make-rdma_rw_ctx_init-initialize-all-used-fields.patch queue-4.7/ib-srpt-limit-the-number-of-sg-elements-per-work-request.patch queue-4.7/ib-core-rdma-rw-api-do-not-exceed-qp-sge-send-limit.patch queue-4.7/target-fix-race-between-iscsi-target-connection-shutdown-abort_task.patch queue-4.7/target-fix-ordered-task-target_setup_cmd_from_cdb-exception-hang.patch queue-4.7/iscsi-target-fix-panic-when-adding-second-tcp-connection-to-iscsi-session.patch queue-4.7/target-fix-missing-complete-during-abort_task-cmd_t_fabric_stop.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html