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authorAndrew Vasquez <andrew.vasquez@qlogic.com>2013-02-08 01:57:42 -0500
committerJames Bottomley <JBottomley@Parallels.com>2013-02-22 12:16:45 +0000
commit0b7e7c53307de217cfc7eeb036c9b8b013d67fcc (patch)
tree44e478f82dbcb9efc4fe272e3901f82644bbabca
parent78d56df6174f6858f79620e0e06ece326a744353 (diff)
[SCSI] qla2xxx: Correct race in loop_state assignment during reset handling.
There's a subtle race in the loop/bus-reset handling whereby a VHA's loop-state can get incorrectly set to 'down' after the loop-reset and firmware's completion of link re-negotiation. The original code incorrectly assumes that firmware AENs would arrive only after mailbox-command execution to initiate the link-flap. Here's a good case with the old code (AENs arrive after mailbox-command completion): qla2xxx [0000:03:00.1]-8012:91: BUS RESET ISSUED nexus=91:0:4. qla2xxx [0000:03:00.1]-287d:91: FCPort state transitioned from ONLINE to LOST - portid=010100. qla2xxx [0000:03:00.1]-580e:91: Asynchronous P2P MODE received. qla2xxx [0000:03:00.1]-287d:91: FCPort state transitioned from ONLINE to LOST - portid=010400. qla2xxx [0000:03:00.1]-802b:91: BUS RESET SUCCEEDED nexus=91:0:4. qla2xxx [0000:03:00.1]-480b:91: Reset marker scheduled. qla2xxx [0000:03:00.1]-5812:91: Port database changed ffff 0006 0000. qla2xxx [0000:03:00.1]-505f:91: Link is operational (4 Gbps). qla2xxx [0000:03:00.1]-480c:91: Reset marker end. qla2xxx [0000:03:00.1]-480f:91: Loop resync scheduled. qla2xxx [0000:03:00.1]-8837:91: F/W Ready - OK. qla2xxx [0000:03:00.1]-883a:91: fw_state=3 (7, 0, 0, 0) curr time=170b8f315. qla2xxx [0000:03:00.1]-280e:91: HBA in F P2P topology. qla2xxx [0000:03:00.1]-2812:91: qla2x00_configure_hba success qla2xxx [0000:03:00.1]-2814:91: Configure loop -- dpc flags = 0x5260. notice how the 'Port database changed' (8014) arrived after the bus-reset handler completed 'BUS RESET SUCCEEDED'. Now, here's a failing case with the old code (AENs arrive before mailbox-command completion): qla2xxx [0000:03:00.1]-8012:91: BUS RESET ISSUED nexus=91:0:0. qla2xxx [0000:03:00.1]-580e:91: Asynchronous P2P MODE received. qla2xxx [0000:03:00.1]-287d:91: FCPort state transitioned from ONLINE to LOST - portid=010100. qla2xxx [0000:03:00.1]-287d:91: FCPort state transitioned from ONLINE to LOST - portid=010400. qla2xxx [0000:03:00.1]-4800:91: DPC handler sleeping. qla2xxx [0000:03:00.1]-5812:91: Port database changed ffff 0006 0000. qla2xxx [0000:03:00.1]-505f:91: Link is operational (4 Gbps). qla2xxx [0000:03:00.1]-802b:91: BUS RESET SUCCEEDED nexus=91:0:0. qla2xxx [0000:03:00.1]-480b:91: Reset marker scheduled. qla2xxx [0000:03:00.1]-480c:91: Reset marker end. qla2xxx [0000:03:00.1]-480f:91: Loop resync scheduled. qla2xxx [0000:03:00.1]-8837:91: F/W Ready - OK. qla2xxx [0000:03:00.1]-883a:91: fw_state=3 (7, 0, 0, 0) curr time=170be9eb2. qla2xxx [0000:03:00.1]-280e:91: HBA in F P2P topology. qla2xxx [0000:03:00.1]-2812:91: qla2x00_configure_hba success qla2xxx [0000:03:00.1]-2814:91: Configure loop -- dpc flags = 0x5260. qla2xxx [0000:03:00.1]-281e:91: Needs RSCN update and loop transition. qla2xxx [0000:03:00.1]-286a:91: qla2x00_configure_loop *** FAILED ***. qla2xxx [0000:03:00.1]-4810:91: Loop resync end. qla2xxx [0000:03:00.1]-4800:91: DPC handler sleeping. This race would ultimately lead to devices go unexpectedly offline until another link-flap or chip-reset would cause driver re-discovery to take place. Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com> Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
-rw-r--r--drivers/scsi/qla2xxx/qla_os.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 2d2afdb4bc87..0612d2557e62 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -1305,14 +1305,14 @@ qla2x00_loop_reset(scsi_qla_host_t *vha)
}
if (ha->flags.enable_lip_full_login && !IS_CNA_CAPABLE(ha)) {
+ atomic_set(&vha->loop_state, LOOP_DOWN);
+ atomic_set(&vha->loop_down_timer, LOOP_DOWN_TIME);
+ qla2x00_mark_all_devices_lost(vha, 0);
ret = qla2x00_full_login_lip(vha);
if (ret != QLA_SUCCESS) {
ql_dbg(ql_dbg_taskm, vha, 0x802d,
"full_login_lip=%d.\n", ret);
}
- atomic_set(&vha->loop_state, LOOP_DOWN);
- atomic_set(&vha->loop_down_timer, LOOP_DOWN_TIME);
- qla2x00_mark_all_devices_lost(vha, 0);
}
if (ha->flags.enable_lip_reset) {