[PATCH 4.19 215/361] scsi: sched/wait: Add wait_event_lock_irq_timeout for TASK_UNINTERRUPTIBLE usage

Greg Kroah-Hartman
2018-11-11T22:28:21Z

From: Nicholas Bellinger <nab@linux-iscsi.org>

commit 25ab0bc334b43bbbe4eabc255006ce42a9424da2 upstream.

Short of reverting commit 00d909a10710 ("scsi: target: Make the session
shutdown code also wait for commands that are being aborted") for v4.19,
target-core needs a wait_event_t macro can be executed using
TASK_UNINTERRUPTIBLE to function correctly with existing fabric drivers that
expect to run with signals pending during session shutdown and active se_cmd
I/O quiesce.

The most notable is iscsi-target/iser-target, while ibmvscsi_tgt invokes
session shutdown logic from userspace via configfs attribute that could also
potentially have signals pending.

So go ahead and introduce wait_event_lock_irq_timeout() to achieve this, and
update + rename __wait_event_lock_irq_timeout() to make it accept 'state' as a
parameter.

Fixes: 00d909a10710 ("scsi: target: Make the session shutdown code also wait for commands that are being aborted")
Cc: <stable@vger.kernel.org> # v4.19+
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Bryant G. Ly <bly@catalogicsoftware.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/linux/wait.h | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)

--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -1052,10 +1052,9 @@ do { \
__ret; \
})

-#define __wait_event_interruptible_lock_irq_timeout(wq_head, condition, \
- lock, timeout) \
+#define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \
___wait_event(wq_head, ___wait_cond_timeout(condition), \
- TASK_INTERRUPTIBLE, 0, timeout, \
+ state, 0, timeout, \
spin_unlock_irq(&lock); \
__ret = schedule_timeout(__ret); \
spin_lock_irq(&lock));
@@ -1089,8 +1088,19 @@ do { \
({ \
long __ret = timeout; \
if (!___wait_cond_timeout(condition)) \
- __ret = __wait_event_interruptible_lock_irq_timeout( \
- wq_head, condition, lock, timeout); \
+ __ret = __wait_event_lock_irq_timeout( \
+ wq_head, condition, lock, timeout, \
+ TASK_INTERRUPTIBLE); \
+ __ret; \
+})
+
+#define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout) \
+({ \
+ long __ret = timeout; \
+ if (!___wait_cond_timeout(condition)) \
+ __ret = __wait_event_lock_irq_timeout( \
+ wq_head, condition, lock, timeout, \
+ TASK_UNINTERRUPTIBLE); \
__ret; \
})