linux-toradex.git/drivers/scsi/sd.h, branch v3.4.45

[SCSI] Handle disk devices which can not process medium access commands

2012-02-19T16:14:52+00:00

We have experienced several devices which fail in a fashion we do not
currently handle gracefully in SCSI. After a failure these devices will
respond to the SCSI primary command set (INQUIRY, TEST UNIT READY, etc.)
but any command accessing the storage medium will time out.

The following patch adds an callback that can be used by upper level
drivers to inspect the results of an error handling command. This in
turn has been used to implement additional checking in the SCSI disk
driver.

If a medium access command fails twice but TEST UNIT READY succeeds both
times in the subsequent error handling we will offline the device. The
maximum number of failed commands required to take a device offline can
be tweaked in sysfs.

Also add a new error flag to scsi_debug which allows this scenario to be
easily reproduced.

[jejb: fix up integer parsing to use kstrtouint]
Signed-off-by: Martin K. Petersen 
Signed-off-by: James Bottomley

[SCSI] sd: remove arbitrary SD_MAX_DISKS namespace limit

2011-10-30T08:58:11+00:00

There is no reason to limit the SCSI disk namespace to sdXXX.

Add new error messages to sd_probe() in the unlikely event that either
ida_get_new() or sd_format_disk_name() fail.

Signed-off-by: Dave Kleikamp 
Signed-off-by: James Bottomley

[SCSI] sd: Logical Block Provisioning update

2011-03-14T23:37:34+00:00

SBC3r26 contains many changes to the Logical Block Provisioning
interfaces (formerly known as Thin Provisioning ditto). This patch
implements support for both the old and new schemes using the same
heuristic as before (whether the LBP VPD page is present).

The new code also allows the provisioning mode (i.e. choice of command)
to be overridden on a per-device basis via sysfs. Two additional modes
are supported in this version:

 - WRITE SAME(10) with the UNMAP bit set

 - WRITE SAME(10) without the UNMAP bit set. This allows us to support
   devices that predate the TP/LBP enhancements in SBC3 and which work
   by way zero-detection

Switching between modes has been consolidated in a helper function that
also updates the block layer topology according to the limitations of
the chosen command.

I experimented with trying WRITE SAME(16) if UNMAP fails, WRITE SAME(10)
if WRITE SAME(16) fails, etc. but found several devices that got
cranky. So for now we'll disable discard if one of the commands
fail. The user still has the option of selecting a different mode in
sysfs.

Signed-off-by: Martin K. Petersen 
Signed-off-by: James Bottomley

[SCSI] sd: implement sd_check_events()

2011-01-14T15:17:34+00:00

Replace sd_media_change() with sd_check_events().

* Move media removed logic into set_media_not_present() and
  media_not_present() and set sdev->changed iff an existing media is
  removed or the device indicates UNIT_ATTENTION.

* Make sd_check_events() sets sdev->changed if previously missing
  media becomes present.

* Event is reported only if sdev->changed is set.

This makes media presence event reported if scsi_disk->media_present
actually changed or the device indicated UNIT_ATTENTION.  For backward
compatibility, SDEV_EVT_MEDIA_CHANGE is generated each time
sd_check_events() detects media change event.

[jejb: fix boot failure]
Signed-off-by: Tejun Heo 
Acked-by: Jens Axboe 
Signed-off-by: James Bottomley

[SCSI] sd: Fix overflow with big physical blocks

2010-10-11T22:33:20+00:00

The hw_sector_size variable could overflow if a device reported huge
physical blocks.  Switch to the more accurate physical_block_size
terminology and make sure we use an unsigned int to match the range
permitted by READ CAPACITY(16).

Signed-off-by: Martin K. Petersen 
Signed-off-by: James Bottomley

[SCSI] sd: Update thin provisioning support

2010-09-17T17:07:55+00:00

Add support for the Thin Provisioning VPD page and use the TPU and TPWS
bits to switch between UNMAP and WRITE SAME(16) for discards.  If no TP
VPD page is present we fall back to old scheme where the max descriptor
count combined with the max lba count are used trigger UNMAP.

Signed-off-by: Martin K. Petersen 
Signed-off-by: James Bottomley

[SCSI] scsi/block: increase flush/sync timeout

2010-09-05T17:57:04+00:00

We have been seeing the flush request timeout with a wide
range of hardware from tgt+iser to FC targets from a major vendor.

After discussions about if the value should be configurable and
what the best value should be, this patch just increases the flush/sync
cache timeout to 1 minute. 2 minutes was determined to be too long, and
making it configurable was troublesome for users.

This patch was made over Linus's tree. It is not made over scsi-misc
or scsi-rc-fixes, because Linus's had block layer changes that my
patch was built over.

Signed-off-by: Mike Christie 
Acked-by: Jens Axboe 
Signed-off-by: James Bottomley

scsi/sd: remove big kernel lock

2010-08-07T16:26:08+00:00

Every user of the BKL in the sd driver is the
result of the pushdown from the block layer
into the open/close/ioctl functions.

The only place that used to rely on the BKL is
the sdkp->openers variable, which gets converted
into an atomic_t.

Nothing else seems to rely on the BKL, since the
functions do not touch global data without holding
another lock, and the open/close functions are
still protected from concurrent execution using
the bdev->bd_mutex.

Signed-off-by: Arnd Bergmann 
Cc: linux-scsi@vger.kernel.org
Cc: "James E.J. Bottomley" 
Acked-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

[SCSI] sd: WRITE SAME(16) / UNMAP support

2009-12-10T14:54:15+00:00

Implement a function for handling discard requests that sends either
WRITE SAME(16) or UNMAP(10) depending on parameters indicated by the
device in the block limits VPD.

Extract unmap constraints and report them to the block layer.

Based in part by a patch by Christoph Hellwig .

Signed-off-by: Martin K. Petersen 
Signed-off-by: James Bottomley

[SCSI] sd: Support disks formatted with DIF Type 2

2009-10-02T14:47:04+00:00

Disks formatted with DIF Type 2 reject READ/WRITE 6/10/12/16 commands
when protection is enabled.  Only the 32-byte variants are supported.

Implement support for issusing 32-byte READ/WRITE and enable Type 2
drives in the protection type detection logic.

Signed-off-by: Martin K. Petersen 
Signed-off-by: James Bottomley