Martin Peschke d79ff14262 [SCSI] zfcp: fix lock imbalance by reworking request queue locking ... This patch adds wait_event_interruptible_lock_irq_timeout(), which is a straight-forward descendant of wait_event_interruptible_timeout() and wait_event_interruptible_lock_irq(). The zfcp driver used to call wait_event_interruptible_timeout() in combination with some intricate and error-prone locking. Using wait_event_interruptible_lock_irq_timeout() as a replacement nicely cleans up that locking. This rework removes a situation that resulted in a locking imbalance in zfcp_qdio_sbal_get(): BUG: workqueue leaked lock or atomic: events/1/0xffffff00/10 last function: zfcp_fc_wka_port_offline+0x0/0xa0 [zfcp] It was introduced by commit c2af7545aa "[SCSI] zfcp: Do not wait for SBALs on stopped queue", which had a new code path related to ZFCP_STATUS_ADAPTER_QDIOUP that took an early exit without a required lock being held. The problem occured when a special, non-SCSI I/O request was being submitted in process context, when the adapter's queues had been torn down. In this case the bug surfaced when the Fibre Channel port connection for a well-known address was closed during a concurrent adapter shut-down procedure, which is a rare constellation. This patch also fixes these warnings from the sparse tool (make C=1): drivers/s390/scsi/zfcp_qdio.c:224:12: warning: context imbalance in 'zfcp_qdio_sbal_check' - wrong count at exit drivers/s390/scsi/zfcp_qdio.c:244:5: warning: context imbalance in 'zfcp_qdio_sbal_get' - unexpected unlock Last but not least, we get rid of that crappy lock-unlock-lock sequence at the beginning of the critical section. It is okay to call zfcp_erp_adapter_reopen() with req_q_lock held. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com> Cc: stable@vger.kernel.org #2.6.35+ Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>		2013-08-22 08:53:30 -07:00
..
acpi	ACPI: Try harder to resolve _ADR collisions for bridges	2013-08-07 22:55:00 +02:00
asm-generic
clocksource
crypto
drm	drm: fix 64 bit drm fixed point helpers	2013-07-30 17:24:13 -04:00
dt-bindings	Pin control fixes for the v3.11 series:	2013-07-28 18:19:27 -07:00
keys
kvm
linux	[SCSI] zfcp: fix lock imbalance by reworking request queue locking	2013-08-22 08:53:30 -07:00
math-emu
media	[media] v4l2: added missing mutex.h include to v4l2-ctrls.h	2013-07-26 10:14:52 -03:00
memory
misc
net	net: rename CONFIG_NET_LL_RX_POLL to CONFIG_NET_RX_BUSY_POLL	2013-08-01 15:11:17 -07:00
pcmcia
ras
rdma
rxrpc
scsi
sound
target
trace	This contains fixes, optimizations and some clean ups	2013-07-22 19:07:24 -07:00
uapi	Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless into for-davem	2013-08-01 14:30:59 -04:00
video
xen	Merge branch 'for-3.11/drivers' of git://git.kernel.dk/linux-block	2013-07-22 19:02:52 -07:00
Kbuild