linux-toradex.git/drivers/scsi/scsi_lib.c, branch v3.4.45

SCSI: scsi_lib: fix scsi_io_completion's SG_IO error propagation

2012-09-14T17:00:23+00:00

commit 27c419739b67decced4650440829b8d51bef954b upstream.

The following v3.4-rc1 commit unmasked an existing bug in scsi_io_completion's
SG_IO error handling: 47ac56d [SCSI] scsi_error: classify some ILLEGAL_REQUEST
sense as a permanent TARGET_ERROR

Given that certain ILLEGAL_REQUEST are now properly categorized as
TARGET_ERROR the host_byte is being set (before host_byte wasn't ever
set for these ILLEGAL_REQUEST).

In scsi_io_completion, initialize req->errors with cmd->result _after_
the SG_IO block that calls __scsi_error_from_host_byte (which may
modify the host_byte).

Before this fix:

    cdb to send: 12 01 01 00 00 00
ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[12, 01, 01, 00, 00, 00],
    mx_sb_len=32, iovec_count=0, dxfer_len=0, timeout=20000, flags=0,
    status=02, masked_status=01, sb[19]=[70, 00, 05, 00, 00, 00, 00, 0b,
    00, 00, 00, 00, 24, 00, 00, 00, 00, 00, 00], host_status=0x10,
    driver_status=0x8, resid=0, duration=0, info=0x1}) = 0
SCSI Status: Check Condition

Sense Information:
sense buffer empty

After:

    cdb to send: 12 01 01 00 00 00
ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[12, 01, 01, 00, 00, 00],
    mx_sb_len=32, iovec_count=0, dxfer_len=0, timeout=20000, flags=0,
    status=02, masked_status=01, sb[19]=[70, 00, 05, 00, 00, 00, 00, 0b,
    00, 00, 00, 00, 24, 00, 00, 00, 00, 00, 00], host_status=0,
    driver_status=0x8, resid=0, duration=0, info=0x1}) = 0
SCSI Status: Check Condition

Sense Information:
 Fixed format, current;  Sense key: Illegal Request
 Additional sense: Invalid field in cdb
 Raw sense data (in hex):
        70 00 05 00 00 00 00 0b  00 00 00 00 24 00 00 00
        00 00 00

Reported-by: Paolo Bonzini 
Tested-by: Paolo Bonzini 
Signed-off-by: Mike Snitzer 
Reviewed-by: Babu Moger 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: James Bottomley

SCSI: Avoid dangling pointer in scsi_requeue_command()

2012-08-09T15:31:28+00:00

commit 940f5d47e2f2e1fa00443921a0abf4822335b54d upstream.

When we call scsi_unprep_request() the command associated with the request
gets destroyed and therefore drops its reference on the device.  If this was
the only reference, the device may get released and we end up with a NULL
pointer deref when we call blk_requeue_request.

Reported-by: Mike Christie 
Signed-off-by: Bart Van Assche 
Reviewed-by: Mike Christie 
Reviewed-by: Tejun Heo 
[jejb: enhance commend and add commit log for stable]
Signed-off-by: James Bottomley 
Signed-off-by: Greg Kroah-Hartman

SCSI: Fix device removal NULL pointer dereference

2012-08-09T15:31:28+00:00

commit 67bd94130015c507011af37858989b199c52e1de upstream.

Use blk_queue_dead() to test whether the queue is dead instead
of !sdev. Since scsi_prep_fn() may be invoked concurrently with
__scsi_remove_device(), keep the queuedata (sdev) pointer in
__scsi_remove_device(). This patch fixes a kernel oops that
can be triggered by USB device removal. See also
http://www.spinics.net/lists/linux-scsi/msg56254.html.

Other changes included in this patch:
- Swap the blk_cleanup_queue() and kfree() calls in
  scsi_host_dev_release() to make that code easier to grasp.
- Remove the queue dead check from scsi_run_queue() since the
  queue state can change anyway at any point in that function
  where the queue lock is not held.
- Remove the queue dead check from the start of scsi_request_fn()
  since it is redundant with the scsi_device_online() check.

Reported-by: Jun'ichi Nomura 
Signed-off-by: Bart Van Assche 
Reviewed-by: Mike Christie 
Reviewed-by: Tejun Heo 
Signed-off-by: James Bottomley 
Signed-off-by: Greg Kroah-Hartman

SCSI: Fix dm-multipath starvation when scsi host is busy

2012-06-09T15:36:06+00:00

commit b7e94a1686c5daef4f649f7f4f839cc294f07710 upstream.

block congestion control doesn't have any concept of fairness across
multiple queues.  This means that if SCSI reports the host as busy in
the queue congestion control it can result in an unfair starvation
situation in dm-mp if there are multiple multipath devices on the same
host.  For example:
http://www.redhat.com/archives/dm-devel/2012-May/msg00123.html

The fix for this is to report only the sdev busy state (and ignore the
host busy state) in the block congestion control call back.
The host is still congested, but the SCSI subsystem will sort out the
congestion in a fair way because it knows the relation between the
queues and the host.

[jejb: fixed up trailing whitespace]
Reported-by: Bernd Schubert 
Tested-by: Bernd Schubert 
Signed-off-by: Jun'ichi Nomura 
Signed-off-by: James Bottomley 
Signed-off-by: Greg Kroah-Hartman

[SCSI] scsi_lib: use correct DMA device in __scsi_alloc_queue

2012-04-22T17:56:18+00:00

Currently, __scsi_alloc_queue uses SCSI host's parent device
as DMA device to set segment boundary. But the parent device may not
refer to the DMA device. For example, for ATA disk, SCSI host's parent
device now refers to ATA port.

Since commit d139b9b([SCSI] scsi_lib_dma: fix bug with dma maps on
nested scsi objects), a new field Scsi_Host->dma_dev was introduced
to refer to the real DMA device.

Use ->dma_dev in __scsi_alloc_queue to correctly set segment
boundary.

Bug report: http://marc.info/?l=linux-ide&m=133177818318187&w=2

Reported-and-tested-by: Jörg Sommer 
Signed-off-by: Lin Ming 
Signed-off-by: James Bottomley

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6

2012-03-22T19:55:29+00:00

SCSI updates from James Bottomley:
 "The update includes the usual assortment of driver updates (lpfc,
  qla2xxx, qla4xxx, bfa, bnx2fc, bnx2i, isci, fcoe, hpsa) plus a huge
  amount of infrastructure work in the SAS library and transport class
  as well as an iSCSI update.  There's also a new SCSI based virtio
  driver."

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (177 commits)
  [SCSI] qla4xxx: Update driver version to 5.02.00-k15
  [SCSI] qla4xxx: trivial cleanup
  [SCSI] qla4xxx: Fix sparse warning
  [SCSI] qla4xxx: Add support for multiple session per host.
  [SCSI] qla4xxx: Export CHAP index as sysfs attribute
  [SCSI] scsi_transport: Export CHAP index as sysfs attribute
  [SCSI] qla4xxx: Add support to display CHAP list and delete CHAP entry
  [SCSI] iscsi_transport: Add support to display CHAP list and delete CHAP entry
  [SCSI] pm8001: fix endian issue with code optimization.
  [SCSI] pm8001: Fix possible racing condition.
  [SCSI] pm8001: Fix bogus interrupt state flag issue.
  [SCSI] ipr: update PCI ID definitions for new adapters
  [SCSI] qla2xxx: handle default case in qla2x00_request_firmware()
  [SCSI] isci: improvements in driver unloading routine
  [SCSI] isci: improve phy event warnings
  [SCSI] isci: debug, provide state-enum-to-string conversions
  [SCSI] scsi_transport_sas: 'enable' phys on reset
  [SCSI] libsas: don't recover end devices attached to disabled phys
  [SCSI] libsas: fixup target_port_protocols for expanders that don't report sata
  [SCSI] libsas: set attached device type and target protocols for local phys
  ...

scsi: remove the second argument of k[un]map_atomic()

2012-03-20T13:48:19+00:00

Signed-off-by: Cong Wang

[SCSI] Ensure discard failure gets treated as a target problem

2012-02-19T15:38:01+00:00

The error reported up the stack for a discard failure did not clearly
indicate that the command was processed and subsequently failed by the
target device.

Return -EREMOTEIO so multipathing does not classify this condition as a
path failure.

Signed-off-by: Martin K. Petersen 
Acked-by: Mike Snitzer 
Signed-off-by: James Bottomley

[SCSI] fix the new host byte settings (DID_TARGET_FAILURE and DID_NEXUS_FAILURE)

2012-02-19T14:08:59+00:00

This patch fixes the host byte settings DID_TARGET_FAILURE and
DID_NEXUS_FAILURE.  The function __scsi_error_from_host_byte, tries to reset
the host byte to DID_OK. But that does not happen because of the OR operation.

Here is the flow.

scsi_softirq_done-> scsi_decide_disposition -> __scsi_error_from_host_byte

Let's take an example with DID_NEXUS_FAILURE. In scsi_decide_disposition,
result will be set as DID_NEXUS_FAILURE (=0x11). Then in
__scsi_error_from_host_byte, when we do OR with DID_OK.  Purpose is to reset
it back to DID_OK. But that does not happen.  This patch fixes this issue.

Signed-off-by: Babu Moger 
Signed-off-by: James Bottomley

[SCSI] don't change sdev starvation list order without request dispatched

2012-01-16T07:54:04+00:00

The sdev is deleted from starved list and then try to dispatch from this
device. It's quite possible the sdev can't eventually dispatch a request,
then the sdev will be in starved list tail. This isn't fair.
There are two cases here:
1. unplug path. scsi_request_fn() calls to scsi_target_queue_ready(), then
the dev is removed from starved list, but quite possible host queue isn't
ready, the dev is moved to starved list without dispatching any request.
2. scsi_run_queue path. It deletes the dev from starved list first (both
global and local starved lists), then handles the dev. Then we could have
the same process like case 1.

This patch fixes the first case. Case 2 isn't fixed, because there is a
rare case scsi_run_queue finds host isn't busy but scsi_request_fn finds
host is busy (other CPU is faster to get host queue depth). Not deleting
the dev from starved list in scsi_run_queue will keep scsi_run_queue
looping (though this is very rare case, because host will become busy).
Fortunately fixing case 1 already gives big improvement for starvation in
my test. In a 12 disk JBOD setup, running file creation under EXT4, this
gives 12% more throughput.

Signed-off-by: Shaohua Li 
Signed-off-by: James Bottomley