4.14-stable review patch. If anyone has any objections, please let me know.
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From: Nicholas Bellinger nab@linux-iscsi.org
commit fd2f928b0ddd2fe8876d4f1344df2ace2b715a4d upstream.
With the recent addition of transport_check_aborted_status() within transport_generic_request_failure() to avoid sending a SCSI status exception after CMD_T_ABORTED w/ TAS=1 has occured, it introduced a COMPARE_AND_WRITE early failure regression.
Namely when COMPARE_AND_WRITE fails and se_device->caw_sem has been taken by sbc_compare_and_write(), if the new check for transport_check_aborted_status() returns true and exits, cmd->transport_complete_callback() -> compare_and_write_post() is skipped never releasing se_device->caw_sem.
This regression was originally introduced by:
commit e3b88ee95b4e4bf3e9729a4695d695b9c7c296c8 Author: Bart Van Assche bart.vanassche@sandisk.com Date: Tue Feb 14 16:25:45 2017 -0800
target: Fix handling of aborted failed commands
To address this bug, move the transport_check_aborted_status() call after transport_complete_task_attr() and cmd->transport_complete_callback().
Cc: Mike Christie mchristi@redhat.com Cc: Hannes Reinecke hare@suse.com Cc: Bart Van Assche bart.vanassche@sandisk.com Signed-off-by: Nicholas Bellinger nab@linux-iscsi.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/target/target_core_transport.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1730,9 +1730,6 @@ void transport_generic_request_failure(s { int ret = 0, post_ret = 0;
- if (transport_check_aborted_status(cmd, 1)) - return; - pr_debug("-----[ Storage Engine Exception; sense_reason %d\n", sense_reason); target_show_cmd("-----[ ", cmd); @@ -1741,6 +1738,7 @@ void transport_generic_request_failure(s * For SAM Task Attribute emulation for failed struct se_cmd */ transport_complete_task_attr(cmd); + /* * Handle special case for COMPARE_AND_WRITE failure, where the * callback is expected to drop the per device ->caw_sem. @@ -1749,6 +1747,9 @@ void transport_generic_request_failure(s cmd->transport_complete_callback) cmd->transport_complete_callback(cmd, false, &post_ret);
+ if (transport_check_aborted_status(cmd, 1)) + return; + switch (sense_reason) { case TCM_NON_EXISTENT_LUN: case TCM_UNSUPPORTED_SCSI_OPCODE: