diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-10-01 16:53:10 -0700 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-10-03 04:24:06 -0700 |
| commit | d8855c154e748c9ccd7c78e6478560ed61438e7d (patch) | |
| tree | e4484595a476c9811dc31a1853c28889dbfd2c50 | |
| parent | b7191253b302a9b98758c3616761ae111b6264b9 (diff) | |
target: Fix recursive COMPARE_AND_WRITE callback failure
This patch addresses a bug when compare_and_write_callback() invoked from
target_complete_ok_work() hits an failure from __target_execute_cmd() ->
cmd->execute_cmd(), that ends up calling transport_generic_request_failure()
-> compare_and_write_post(), thus causing SCF_COMPARE_AND_WRITE_POST to
incorrectly be set.
The result of this bug is that target_complete_ok_work() no longer hits
the if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST) check
that forces an immediate return, and instead double completes the se_cmd
in question, triggering an OOPs in the process.
This patch changes compare_and_write_post() to only set this bit when a
failure has not already occured to ensure the immediate return from within
target_complete_ok_work(), and thus allow transport_generic_request_failure()
to handle the sending of the CHECK_CONDITION exception status.
Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Tested-by: Thomas Glanzmann <thomas@glanzmann.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
| -rw-r--r-- | drivers/target/target_core_sbc.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index a9dca116011e..1393d0ed746a 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -349,7 +349,16 @@ static sense_reason_t compare_and_write_post(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; - cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST; + /* + * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through + * within target_complete_ok_work() if the command was successfully + * sent to the backend driver. + */ + spin_lock_irq(&cmd->t_state_lock); + if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status) + cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST; + spin_unlock_irq(&cmd->t_state_lock); + /* * Unlock ->caw_sem originally obtained during sbc_compare_and_write() * before the original READ I/O submission. |