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author | Nathan Lynch <ntl@pobox.com> | 2005-06-02 17:15:09 -0500 |
---|---|---|
committer | James Bottomley <jejb@mulgrave.(none)> | 2005-06-03 09:38:55 -0500 |
commit | c92715b3c22e94105a8fd9e4a23047d05c5077e7 (patch) | |
tree | cb911d630389c13e82572139a00048963311e610 /drivers/scsi/scsi_scan.c | |
parent | 18e144d32cd3dae6953c385e4b376ef9688b61b0 (diff) | |
download | lwn-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.c | 1 |
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) |