Martin Peschke bda5d1efa0 SCSI: zfcp: fix lock imbalance by reworking request queue locking ... commit d79ff14262 upstream. 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> Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2013-08-29 09:47:39 -07:00
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acpi	ACPI: Try harder to resolve _ADR collisions for bridges	2013-08-29 09:47:29 -07:00
asm-generic	Fix TLB gather virtual address range invalidation corner cases	2013-08-20 08:43:05 -07:00
clocksource	ARM: late Exynos multiplatform changes	2013-05-07 11:28:42 -07:00
crypto
drm	Merge branch 'drm-radeon-sun-hainan' of git://people.freedesktop.org/~airlied/linux	2013-05-21 08:50:57 -07:00
dt-bindings
keys
linux	SCSI: zfcp: fix lock imbalance by reworking request queue locking	2013-08-29 09:47:39 -07:00
math-emu
media	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media	2013-06-18 06:25:08 -10:00
memory
misc
net	ndisc: Add missing inline to ndisc_addr_option_pad	2013-08-11 18:35:26 -07:00
pcmcia
ras
rdma
rxrpc
scsi	Merge branch 'postmerge' into for-linus	2013-05-10 07:54:01 -07:00
sound	ASoC: dapm: Treat DAI widgets like AIF widgets for power	2013-06-07 15:54:50 +01:00
target	iscsi-target: Fix iscsit_sequence_cmd reject handling for iser	2013-08-04 16:51:17 +08:00
trace	Fixed regressions (two stability regressions and a performance	2013-05-14 09:30:54 -07:00
uapi	firewire: fix libdc1394/FlyCap2 iso event regression	2013-08-04 16:50:38 +08:00
video	Merge branch 'fbdev-3.10-fixes' of git://gitorious.org/linux-omap-dss2/linux into linux-fbdev/for-3.10-fixes	2013-05-29 17:00:34 +08:00
xen	xenbus: delay xenbus frontend resume if xenstored is not running	2013-05-29 09:04:19 -04:00
Kbuild