summaryrefslogtreecommitdiff
path: root/drivers/scsi/scsi_scan.c
diff options
context:
space:
mode:
authorNathan Lynch <ntl@pobox.com>2005-06-02 17:15:09 -0500
committerJames Bottomley <jejb@mulgrave.(none)>2005-06-03 09:38:55 -0500
commitc92715b3c22e94105a8fd9e4a23047d05c5077e7 (patch)
treecb911d630389c13e82572139a00048963311e610 /drivers/scsi/scsi_scan.c
parent18e144d32cd3dae6953c385e4b376ef9688b61b0 (diff)
downloadlwn-c92715b3c22e94105a8fd9e4a23047d05c5077e7.tar.gz
lwn-c92715b3c22e94105a8fd9e4a23047d05c5077e7.zip
[SCSI] fix slab corruption during ipr probe
With CONFIG_DEBUG_SLAB=y I see slab corruption messages during boot on pSeries machines with IPR adapters with any 2.6.12-rc kernel. The change which seems to have introduced the problem is "SCSI: revamp target scanning routines" and may be found at: http://marc.theaimsgroup.com/?l=bk-commits-head&m=111093946426333&w=2 In order to revert that in a 2.6.12-rc1 tree, I had to revert "target code updates to support scanned targets" first: http://marc.theaimsgroup.com/?l=bk-commits-head&m=111094132524649&w=2 With both patches reverted, the corruption messages go away. ipr: IBM Power RAID SCSI Device Driver version: 2.0.13 (February 21, 2005) ipr 0001:d0:01.0: Found IOA with IRQ: 167 ipr 0001:d0:01.0: Starting IOA initialization sequence. ipr 0001:d0:01.0: Adapter firmware version: 020A005C ipr 0001:d0:01.0: IOA initialized. scsi0 : IBM 570B Storage Adapter Vendor: IBM Model: VSBPD4E1 U4SCSI Rev: 4770 Type: Enclosure ANSI SCSI revision: 02 Vendor: IBM H0 Model: HUS103036FL3800 Rev: RPQF Type: Direct-Access ANSI SCSI revision: 04 Vendor: IBM H0 Model: HUS103036FL3800 Rev: RPQF Type: Direct-Access ANSI SCSI revision: 04 Vendor: IBM H0 Model: HUS103036FL3800 Rev: RPQF Type: Direct-Access ANSI SCSI revision: 04 Vendor: IBM H0 Model: HUS103036FL3800 Rev: RPQF Type: Direct-Access ANSI SCSI revision: 04 Vendor: IBM Model: VSBPD4E1 U4SCSI Rev: 4770 Type: Enclosure ANSI SCSI revision: 02 Slab corruption: start=c0000001e8de5268, len=512 Redzone: 0x5a2cf071/0x5a2cf071. Last user: [<c00000000029c3a0>](.scsi_target_dev_release+0x28/0x50) 080: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6a Prev obj: start=c0000001e8de5050, len=512 Redzone: 0x5a2cf071/0x5a2cf071. Last user: [<0000000000000000>](0x0) 000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Next obj: start=c0000001e8de5480, len=512 Redzone: 0x170fc2a5/0x170fc2a5. Last user: [<c000000000228d7c>](.as_init_queue+0x5c/0x228) 000: c0 00 00 01 e8 83 26 08 00 00 00 00 00 00 00 00 010: 00 00 00 00 00 00 00 00 c0 00 00 01 e8 de 54 98 Slab corruption: start=c0000001e8de5268, len=512 Redzone: 0x5a2cf071/0x5a2cf071. Last user: [<c00000000029c3a0>](.scsi_target_dev_release+0x28/0x50) 080: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6a Prev obj: start=c0000001e8de5050, len=512 Redzone: 0x5a2cf071/0x5a2cf071. Last user: [<0000000000000000>](0x0) 000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b Next obj: start=c0000001e8de5480, len=512 Redzone: 0x170fc2a5/0x170fc2a5. Last user: [<c000000000228d7c>](.as_init_queue+0x5c/0x228) 000: c0 00 00 01 e8 83 26 08 00 00 00 00 00 00 00 00 010: 00 00 00 00 00 00 00 00 c0 00 00 01 e8 de 54 98 ... I did some digging and the problem seems to be a refcounting issue in __scsi_add_device. The target gets freed in scsi_target_reap, and then __scsi_add_device tries to do another device_put on it. Signed-off-by: Nathan Lynch <ntl@pobox.com> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/scsi_scan.c')
-rw-r--r--drivers/scsi/scsi_scan.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index cca772624ae7..8d0d302844a1 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1197,6 +1197,7 @@ struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
if (!starget)
return ERR_PTR(-ENOMEM);
+ get_device(&starget->dev);
down(&shost->scan_mutex);
res = scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
if (res != SCSI_SCAN_LUN_PRESENT)