[SCSI] Fix regressions in scsi_internal_device_block
Deleting a SCSI device on a blocked fc_remote_port (before
fast_io_fail_tmo fires) results in a hanging thread:
STACK:
0 schedule+1108 [0x5cac48]
1 schedule_timeout+528 [0x5cb7fc]
2 wait_for_common+266 [0x5ca6be]
3 blk_execute_rq+160 [0x354054]
4 scsi_execute+324 [0x3b7ef4]
5 scsi_execute_req+162 [0x3b80ca]
6 sd_sync_cache+138 [0x3cf662]
7 sd_shutdown+138 [0x3cf91a]
8 sd_remove+112 [0x3cfe4c]
9 __device_release_driver+124 [0x3a08b8]
10 device_release_driver+60 [0x3a0a5c]
11 bus_remove_device+266 [0x39fa76]
12 device_del+340 [0x39d818]
13 __scsi_remove_device+204 [0x3bcc48]
14 scsi_remove_device+66 [0x3bcc8e]
15 sysfs_schedule_callback_work+50 [0x260d66]
16 worker_thread+622 [0x162326]
17 kthread+160 [0x1680b0]
18 kernel_thread_starter+6 [0x10aaea]
During the delete, the SCSI device is in moved to SDEV_CANCEL. When
the FC transport class later calls scsi_target_unblock, this has no
effect, since scsi_internal_device_unblock ignores SCSI devics in this
state.
It looks like all these are regressions caused by:
5c10e63c943b4c67561ddc6bf61e01d4141f881f
[SCSI] limit state transitions in scsi_internal_device_unblock
Fix by rejecting offline and cancel in the state transition.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
[jejb: Original patch by Christof Schmitt, modified by Mike Christie]
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
1 file changed