Christof Schmitt d74cf7c3e9 [SCSI] zfcp: Fix hang when offlining device with offline chpid ... Running chchp --vary 0 and chccwdev -d on a FCP device with scsi devices attached can lead to this thread hanging: ================================================================ STACK TRACE FOR TASK: 0x2fbfcc00 (kslowcrw) STACK: 0 schedule+1136 [0x45f99c] 1 schedule_timeout+534 [0x46054e] 2 wait_for_common+374 [0x45f442] 3 blk_execute_rq+160 [0x217a2c] 4 scsi_execute+278 [0x26daf2] 5 scsi_execute_req+150 [0x26dc86] 6 sd_sync_cache+138 [0x28460a] 7 sd_shutdown+130 [0x28486a] 8 sd_remove+104 [0x284c84] 9 __device_release_driver+152 [0x257430] 10 device_release_driver+56 [0x2575c8] 11 bus_remove_device+214 [0x25672a] 12 device_del+352 [0x25456c] 13 __scsi_remove_device+108 [0x272630] 14 scsi_remove_device+66 [0x2726ba] 15 zfcp_ccw_remove+824 [0x335558] 16 ccw_device_remove+62 [0x2b3f2a] 17 __device_release_driver+152 [0x257430] 18 device_release_driver+56 [0x2575c8] 19 bus_remove_device+214 [0x25672a] 20 device_del+352 [0x25456c] 21 ccw_device_unregister+92 [0x2b48c4] 22 io_subchannel_remove+108 [0x2b4950] 23 css_remove+62 [0x2af7ee] 24 __device_release_driver+152 [0x257430] 25 device_release_driver+56 [0x2575c8] 26 bus_remove_device+214 [0x25672a] 27 device_del+352 [0x25456c] 28 device_unregister+38 [0x25464a] 29 css_sch_device_unregister+68 [0x2af97c] 30 ccw_device_call_sch_unregister+78 [0x2b581e] 31 worker_thread+604 [0x69eb0] 32 kthread+154 [0x6ff42] 33 kernel_thread_starter+6 [0x1c952] ================================================================ The problem is that the chchp --vary 0 leads to zfcp first calling fc_remote_port_delete which blocks all scsi devices on the remote port. Calling scsi_remove_device later lets the sd driver issue a SYNCHRONIZE_CACHE command. This command stays on the "stopped" request requeue because the SCSI device is blocked. Fix this by first removing the scsi and fc hosts which removes all scsi devices and do not use scsi_remove_device. Reviewed-by: Felix Beck <felix.beck@de.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>		2009-10-02 09:50:21 -05:00
..
block	Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6	2009-09-23 10:02:14 -07:00
char	headers: utsname.h redux	2009-09-23 18:13:10 -07:00
cio	[S390] qdio: change state of all primed input buffers	2009-09-22 22:58:43 +02:00
crypto	[S390] zcrypt: Do not add/remove devices in s/r callbacks	2009-09-22 22:58:46 +02:00
kvm	[S390] kvm: use console_initcall() to initialize s390 virtio console	2009-09-11 10:29:52 +02:00
net	trivial: remove unnecessary semicolons	2009-09-21 15:14:58 +02:00
scsi	[SCSI] zfcp: Fix hang when offlining device with offline chpid	2009-10-02 09:50:21 -05:00
Makefile	[S390] split/move machine check handler code	2009-03-26 15:24:10 +01:00