f45a54214a
======================================================= [ INFO: possible circular locking dependency detected ] 2.6.31-39.x.20090917-s390xdefault #1 ------------------------------------------------------- kslowcrw/83 is trying to acquire lock: (&adapter->scan_work){+.+.+.}, at: [<0000000000169c5c>] __cancel_work_timer+0x64/0x3d4 but task is already holding lock: (&zfcp_data.config_mutex){+.+.+.}, at: [<00000000004671ea>] zfcp_ccw_remove+0x66/0x384 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&zfcp_data.config_mutex){+.+.+.}: [<0000000000189962>] __lock_acquire+0xe26/0x1834 [<000000000018a4b6>] lock_acquire+0x146/0x178 [<000000000058cb5a>] mutex_lock_nested+0x82/0x3ec [<0000000000477170>] zfcp_fc_scan_ports+0x3ec/0x728 [<0000000000168e34>] worker_thread+0x278/0x3a8 [<000000000016ff08>] kthread+0x9c/0xa4 [<0000000000109ebe>] kernel_thread_starter+0x6/0xc [<0000000000109eb8>] kernel_thread_starter+0x0/0xc -> #0 (&adapter->scan_work){+.+.+.}: [<0000000000189e60>] __lock_acquire+0x1324/0x1834 [<000000000018a4b6>] lock_acquire+0x146/0x178 [<0000000000169c9a>] __cancel_work_timer+0xa2/0x3d4 [<0000000000465cb2>] zfcp_adapter_dequeue+0x32/0x14c [<00000000004673e4>] zfcp_ccw_remove+0x260/0x384 [<00000000004250f6>] ccw_device_remove+0x42/0x1ac [<00000000003cb6be>] __device_release_driver+0x9a/0x10c [<00000000003cb856>] device_release_driver+0x3a/0x4c [<00000000003ca94c>] bus_remove_device+0xcc/0x114 [<00000000003c8506>] device_del+0x162/0x21c [<0000000000425ff2>] ccw_device_unregister+0x5e/0x7c [<000000000042607e>] io_subchannel_remove+0x6e/0x9c [<000000000041ff9a>] css_remove+0x3e/0x7c [<00000000003cb6be>] __device_release_driver+0x9a/0x10c [<00000000003cb856>] device_release_driver+0x3a/0x4c [<00000000003ca94c>] bus_remove_device+0xcc/0x114 [<00000000003c8506>] device_del+0x162/0x21c [<00000000003c85e8>] device_unregister+0x28/0x38 [<0000000000420152>] css_sch_device_unregister+0x46/0x58 [<00000000004276a6>] io_subchannel_sch_event+0x28e/0x794 [<0000000000420442>] css_evaluate_known_subchannel+0x46/0xd0 [<0000000000420ebc>] slow_eval_known_fn+0x88/0xa0 [<00000000003caffa>] bus_for_each_dev+0x7e/0xd0 [<000000000042188c>] for_each_subchannel_staged+0x6c/0xd4 [<0000000000421a00>] css_slow_path_func+0x54/0xd8 [<0000000000168e34>] worker_thread+0x278/0x3a8 [<000000000016ff08>] kthread+0x9c/0xa4 [<0000000000109ebe>] kernel_thread_starter+0x6/0xc [<0000000000109eb8>] kernel_thread_starter+0x0/0xc cancel_work_sync is called while holding the config_mutex. But the work that is being cancelled or flushed also uses the config_mutex. Fix the resulting deadlock possibility by calling cancel_work_sync earlier without holding the mutex. The best place to do is is after offlining the device. No new port scan work will be scheduled for the offline device, so this is a safe place to call cancel_work_sync. 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> |
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| .. | ||
| Makefile | ||
| zfcp_aux.c | ||
| zfcp_ccw.c | ||
| zfcp_cfdc.c | ||
| zfcp_dbf.c | ||
| zfcp_dbf.h | ||
| zfcp_def.h | ||
| zfcp_erp.c | ||
| zfcp_ext.h | ||
| zfcp_fc.c | ||
| zfcp_fsf.c | ||
| zfcp_fsf.h | ||
| zfcp_qdio.c | ||
| zfcp_scsi.c | ||
| zfcp_sysfs.c | ||