[SCSI] ibmvfc: Fix deadlock in EH
authorBrian King <brking@linux.vnet.ibm.com>
Thu, 28 May 2009 21:17:28 +0000 (16:17 -0500)
committerJames Bottomley <James.Bottomley@HansenPartnership.com>
Mon, 8 Jun 2009 18:07:42 +0000 (13:07 -0500)
commit43c8da907ccc656935d1085701f4db83385d8a59
tree586046bab83b676553104d7b80894863ba31872a
parent7d0e462247241b8ec2d377306203b58c7f423553
[SCSI] ibmvfc: Fix deadlock in EH

Fixes the following deadlock scenario shown below. We currently allow
queuecommand to send commands when the ibmvfc workqueue is scanning for
new rports, so we should also allow EH to function at this time as well.

scsi_eh_3     D 0000000000000000 12304  1279      2
Call Trace:
[c0000002f7257730] [c0000002f72577e0] 0xc0000002f72577e0 (unreliable)
[c0000002f7257900] [c0000000000118f4] .__switch_to+0x158/0x1a0
[c0000002f72579a0] [c0000000004f8b40] .schedule+0x8d4/0x9dc
[c0000002f7257b60] [c0000000004f8f08] .schedule_timeout+0xa8/0xe8
[c0000002f7257c50] [d0000000001d23e0] .ibmvfc_wait_while_resetting+0xe4/0x140 [ibmvfc]
[c0000002f7257d20] [d0000000001d3984] .ibmvfc_eh_abort_handler+0x60/0xe4 [ibmvfc]
[c0000002f7257dc0] [d000000000366714] .scsi_error_handler+0x38c/0x674 [scsi_mod]
[c0000002f7257f00] [c0000000000a7470] .kthread+0x78/0xc4
[c0000002f7257f90] [c000000000029b8c] .kernel_thread+0x4c/0x68
ibmvfc_3      D 0000000000000000 12432  1280      2
Call Trace:
[c0000002f7253540] [c0000002f72535f0] 0xc0000002f72535f0 (unreliable)
[c0000002f7253710] [c0000000000118f4] .__switch_to+0x158/0x1a0
[c0000002f72537b0] [c0000000004f8b40] .schedule+0x8d4/0x9dc
[c0000002f7253970] [c0000000004f8e98] .schedule_timeout+0x38/0xe8
[c0000002f7253a60] [c0000000004f80cc] .wait_for_common+0x138/0x220
[c0000002f7253b40] [c0000000000a2784] .flush_cpu_workqueue+0xac/0xcc
[c0000002f7253c10] [c0000000000a2960] .flush_workqueue+0x58/0xa0
[c0000002f7253ca0] [d0000000000827fc] .fc_flush_work+0x4c/0x64 [scsi_transport_fc]
[c0000002f7253d20] [d000000000082db4] .fc_remote_port_add+0x48/0x6c4 [scsi_transport_fc]
[c0000002f7253dd0] [d0000000001d7d04] .ibmvfc_work+0x820/0xa7c [ibmvfc]
[c0000002f7253f00] [c0000000000a7470] .kthread+0x78/0xc4
[c0000002f7253f90] [c000000000029b8c] .kernel_thread+0x4c/0x68
fc_wq_3       D 0000000000000000 10720  1283      2
Call Trace:
[c0000002f559ac30] [c0000002f559ace0] 0xc0000002f559ace0 (unreliable)
[c0000002f559ae00] [c0000000000118f4] .__switch_to+0x158/0x1a0
[c0000002f559aea0] [c0000000004f8b40] .schedule+0x8d4/0x9dc
[c0000002f559b060] [c0000000004f8e98] .schedule_timeout+0x38/0xe8
[c0000002f559b150] [c0000000004f80cc] .wait_for_common+0x138/0x220
[c0000002f559b230] [c0000000002721c4] .blk_execute_rq+0xb4/0x100
[c0000002f559b360] [d00000000036a1f8] .scsi_execute+0x118/0x194 [scsi_mod]
[c0000002f559b420] [d00000000036a32c] .scsi_execute_req+0xb8/0x124 [scsi_mod]
[c0000002f559b500] [d0000000000c1330] .sd_sync_cache+0x8c/0x108 [sd_mod]
[c0000002f559b5e0] [d0000000000c15b4] .sd_shutdown+0x9c/0x158 [sd_mod]
[c0000002f559b660] [d0000000000c16d0] .sd_remove+0x60/0xb4 [sd_mod]
[c0000002f559b700] [c000000000392ecc] .__device_release_driver+0xd0/0x118
[c0000002f559b7a0] [c000000000393080] .device_release_driver+0x30/0x54
[c0000002f559b830] [c000000000392108] .bus_remove_device+0x128/0x16c
[c0000002f559b8d0] [c00000000038f94c] .device_del+0x158/0x234
[c0000002f559b960] [d00000000036f078] .__scsi_remove_device+0x5c/0xd4 [scsi_mod]
[c0000002f559b9f0] [d00000000036f124] .scsi_remove_device+0x34/0x58 [scsi_mod]
[c0000002f559ba80] [d00000000036f204] .__scsi_remove_target+0xb4/0x120 [scsi_mod]
[c0000002f559bb10] [d00000000036f338] .__remove_child+0x2c/0x44 [scsi_mod]
[c0000002f559bb90] [c00000000038f11c] .device_for_each_child+0x54/0xb4
[c0000002f559bc50] [d00000000036f2e0] .scsi_remove_target+0x70/0x9c [scsi_mod]
[c0000002f559bce0] [d000000000083454] .fc_starget_delete+0x24/0x3c [scsi_transport_fc]
[c0000002f559bd70] [c0000000000a2368] .run_workqueue+0x118/0x208
[c0000002f559be30] [c0000000000a2580] .worker_thread+0x128/0x154
[c0000002f559bf00] [c0000000000a7470] .kthread+0x78/0xc4
[c0000002f559bf90] [c000000000029b8c] .kernel_thread+0x4c/0x68

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
drivers/scsi/ibmvscsi/ibmvfc.c
drivers/scsi/ibmvscsi/ibmvfc.h