linux-toradex.git/drivers/ata/libata-scsi.c, branch v3.0.80

libata: fix Null pointer dereference on disk error

2013-01-17T16:43:54+00:00

commit 26cd4d65deba587f3cf2329b6869ce02bcbe68ec upstream.

Following oops were observed when disk error happened:

[ 4272.896937] sd 0:0:0:0: [sda] Unhandled error code
[ 4272.896939] sd 0:0:0:0: [sda] Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK
[ 4272.896942] sd 0:0:0:0: [sda] CDB: Read(10): 28 00 00 5a de a7 00 00 08 00
[ 4272.896951] end_request: I/O error, dev sda, sector 5955239
[ 4291.574947] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 4291.658305] IP: [] ahci_activity_show+0x1/0x40
[ 4291.730090] PGD 76dbbc067 PUD 6c4fba067 PMD 0
[ 4291.783408] Oops: 0000 [#1] SMP
[ 4291.822100] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/sw_activity
[ 4291.934235] CPU 9
[ 4291.958301] Pid: 27942, comm: hwinfo ......

ata_scsi_find_dev could return NULL, so ata_scsi_activity_{show,store} should check if atadev is NULL.

Signed-off-by: Xiaotian Feng 
Cc: James Bottomley 
Signed-off-by: Jeff Garzik 
Signed-off-by: Greg Kroah-Hartman

libata/sas: only set FROZEN flag if new EH is supported

2011-06-23T20:41:26+00:00

On 16.06.2011 [08:28:39 -0500], Brian King wrote:
> On 06/16/2011 02:51 AM, Tejun Heo wrote:
> > On Wed, Jun 15, 2011 at 04:34:17PM -0700, Nishanth Aravamudan wrote:
> >>> That looks like the right thing to do. For ipr's usage of
> >>> libata, we don't have the concept of a port frozen state, so this flag
> >>> should really never get set. The alternate way to fix this would be to
> >>> only set ATA_PFLAG_FROZEN in ata_port_alloc if ap->ops->error_handler
> >>> is not NULL.
> >>
> >> It seemed like ipr is as you say, but I wasn't sure if it was
> >> appropriate to make the change above in the common libata-scis code or
> >> not. I don't want to break some other device on accident.
> >>
> >> Also, I tried your suggestion, but I don't think that can happen in
> >> ata_port_alloc? ata_port_alloc is allocated ap itself, and it seems like
> >> ap->ops typically gets set only after ata_port_alloc returns?
> >
> > Maybe we can test error_handler in ata_sas_port_start()?
>
> Good point. Since libsas is converted to the new eh now, we would need to have
> this test.

Commit 7b3a24c57d2eeda8dba9c205342b12689c4679f9 ("ahci: don't enable
port irq before handler is registered") caused a regression for CD-ROMs
attached to the IPR SATA bus on Power machines:

  ata_port_alloc: ENTER
  ata_port_probe: ata1: bus probe begin
  ata1.00: ata_dev_read_id: ENTER
  ata1.00: failed to IDENTIFY (I/O error, err_mask=0x40)
  ata1.00: ata_dev_read_id: ENTER
  ata1.00: failed to IDENTIFY (I/O error, err_mask=0x40)
  ata1.00: limiting speed to UDMA7:PIO5
  ata1.00: ata_dev_read_id: ENTER
  ata1.00: failed to IDENTIFY (I/O error, err_mask=0x40)
  ata1.00: disabled
  ata_port_probe: ata1: bus probe end
  scsi_alloc_sdev: Allocation failure during SCSI scanning, some SCSI devices might not be configured

The FROZEN flag added in that commit is only cleared by the new EH code,
which is not used by ipr. Clear this flag in the SAS code if we don't
support new EH.

Reported-by: Benjamin Herrenschmidt 
Signed-off-by: Nishanth Aravamudan 
Signed-off-by: Jeff Garzik

Merge branch 'for-2.6.40/core' of git://git.kernel.dk/linux-2.6-block

2011-05-25T16:14:07+00:00

* 'for-2.6.40/core' of git://git.kernel.dk/linux-2.6-block: (40 commits)
  cfq-iosched: free cic_index if cfqd allocation fails
  cfq-iosched: remove unused 'group_changed' in cfq_service_tree_add()
  cfq-iosched: reduce bit operations in cfq_choose_req()
  cfq-iosched: algebraic simplification in cfq_prio_to_maxrq()
  blk-cgroup: Initialize ioc->cgroup_changed at ioc creation time
  block: move bd_set_size() above rescan_partitions() in __blkdev_get()
  block: call elv_bio_merged() when merged
  cfq-iosched: Make IO merge related stats per cpu
  cfq-iosched: Fix a memory leak of per cpu stats for root group
  backing-dev: Kill set but not used var in  bdi_debug_stats_show()
  block: get rid of on-stack plugging debug checks
  blk-throttle: Make no throttling rule group processing lockless
  blk-cgroup: Make cgroup stat reset path blkg->lock free for dispatch stats
  blk-cgroup: Make 64bit per cpu stats safe on 32bit arch
  blk-throttle: Make dispatch stats per cpu
  blk-throttle: Free up a group only after one rcu grace period
  blk-throttle: Use helper function to add root throtl group to lists
  blk-throttle: Introduce a helper function to fill in device details
  blk-throttle: Dynamically allocate root group
  blk-cgroup: Allow sleeping while dynamically allocating a group
  ...

libata: Use Maximum Write Same Length to report discard size limit

2011-05-20T00:46:01+00:00

Previously we used Maximum Unmap LBA Count in the Block Limits VPD to
signal the maximum number of sectors we could handle in a single Write
Same command.

Starting with SBC3r26 the Block Limits VPD has an explicit limit on the
number of blocks in a Write Same. This means we can stop abusing a field
related to the Unmap command and let our SAT use the proper value in the
VPD (Maximum Write Same Length).

Signed-off-by: Martin K. Petersen 
Signed-off-by: Jeff Garzik 
Cc: stable@kernel.org

SATA: enable non-queueable flush flag

2011-05-06T17:36:25+00:00

Enable non-queueable flush flag for SATA.

Stable: 2.6.39 only

Cc: stable@kernel.org
Signed-off-by: Shaohua Li 
Acked-by: Tejun Heo 
Acked-by: Jeff Garzik 
Signed-off-by: Jens Axboe

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi

libata: Include WWN ID in inquiry VPD emulation

2011-03-14T06:59:37+00:00

As per SAT-3 the WWN ID should be included in the VPD page 0x83
(device identification) emulation.

Signed-off-by: Hannes Reinecke 
Acked-by: Tejun Heo 
Signed-off-by: Jeff Garzik

libata: fix locking for sas paths

2011-03-02T07:36:45+00:00

For historical reasons, libsas uses the scsi host lock as the ata port
lock, and libata always uses the ata host.  For the old eh, this was
largely irrelevant since the two locks were never mixed inside the
code.  However, the new eh has a case where it nests acquisition of
the host lock inside the port lock (this does look rather deadlock
prone).  Obviously this would be an instant deadlock if the port lock
were the host lock, so switch the libsas paths to use the ata host
lock as well.

Signed-off-by: James Bottomley 
Signed-off-by: Jeff Garzik

libata: plumb sas port scan into standard libata paths

2011-03-02T07:36:45+00:00

The function ata_sas_port_init() has always really done its own thing.
However, as a precursor to moving to the libata new eh, it has to be
properly using the standard libata scan paths.  This means separating
the current libata scan paths into pieces which can be shared with
libsas and pieces which cant (really just the async call and the host
scan).

Signed-off-by: James Bottomley 
Signed-off-by: Jeff Garzik

libata: set queue DMA alignment to sector size for ATAPI too

2011-01-28T08:16:20+00:00

ata_pio_sectors() expects buffer for each sector to be contained in a
single page; otherwise, it ends up overrunning the first page.  This
is achieved by setting queue DMA alignment.  If sector_size is smaller
than PAGE_SIZE and all buffers are sector_size aligned, buffer for
each sector is always contained in a single page.

This wasn't applied to ATAPI devices but IDENTIFY_PACKET is executed
as ATA_PROT_PIO and thus uses ata_pio_sectors().  Newer versions of
udev issue IDENTIFY_PACKET with unaligned buffer triggering the
problem and causing oops.

This patch fixes the problem by setting sdev->sector_size to
ATA_SECT_SIZE on ATATPI devices and always setting DMA alignment to
sector_size.  While at it, add a warning for the unlikely but still
possible scenario where sector_size is larger than PAGE_SIZE, in which
case the alignment wouldn't be enough.

Signed-off-by: Tejun Heo 
Reported-by: John Stanley 
Tested-by: John Stanley 
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik