Messages in this thread Patch in this message | | | From | "Nicholas A. Bellinger" <> | Subject | [PATCH 2/6] target: Fix caw_sem leak in transport_generic_request_failure | Date | Wed, 8 Nov 2017 04:31:48 +0000 |
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From: Nicholas Bellinger <nab@linux-iscsi.org>
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> --- drivers/target/target_core_transport.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index c33d1e9..d02218c 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1729,9 +1729,6 @@ void transport_generic_request_failure(struct se_cmd *cmd, { 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); @@ -1740,6 +1737,7 @@ void transport_generic_request_failure(struct se_cmd *cmd, * 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. @@ -1748,6 +1746,9 @@ void transport_generic_request_failure(struct se_cmd *cmd, 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: -- 1.9.1
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