linux-toradex.git/drivers/scsi/sd_dif.c, branch v4.2.7

sd: Fix missing ATO tag check

2015-04-16T17:37:12+00:00

3aec2f41a8bae introduced a merge error where we would end up check for
sdkp instead of sdkp->ATO. Fix this so we register app tag capability
correctly.

Signed-off-by: Martin K. Petersen 
Cc:  # v3.17+
Reviewed-by: Sagi Grimberg 
Signed-off-by: James Bottomley

sd: Honor block layer integrity handling flags

2014-09-30T21:17:35+00:00

A set of flags introduced in the block layer enable better control over
how protection information is handled. These flags are useful for both
error injection and data recovery purposes. Checking can be enabled and
disabled for controller and disk, and the guard tag format is now a
per-I/O property.

Update sd_protect_op to communicate the relevant information to the
low-level device driver via a set of flags in scsi_cmnd.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Sagi Grimberg 
Acked-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: Add T10 Protection Information functions

2014-09-27T15:14:59+00:00

The T10 Protection Information format is also used by some devices that
do not go through the SCSI layer (virtual block devices, NVMe). Relocate
the relevant functions to a block layer library that can be used without
involving SCSI.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: Integrity checksum flag

2014-09-27T15:14:55+00:00

Make the choice of checksum a per-I/O property by introducing a flag
that can be inspected by the SCSI layer. There are several reasons for
this:

 1. It allows us to switch choice of checksum without unloading and
    reloading the HBA driver.

 2. During error recovery we need to be able to tell the HBA that
    checksums read from disk should not be verified and converted to IP
    checksums.

 3. For error injection purposes we need to be able to write a bad guard
    tag to storage. Since the storage device only supports T10 CRC we
    need to be able to disable IP checksum conversion on the HBA.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

block: Relocate bio integrity flags

2014-09-27T15:14:54+00:00

Move flags affecting the integrity code out of the bio bi_flags and into
the block integrity payload.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

block: Add a disk flag to block integrity profile

2014-09-27T15:14:51+00:00

So far we have relied on the app tag size to determine whether a disk
has been formatted with T10 protection information or not. However, not
all target devices provide application tag storage.

Add a flag to the block integrity profile that indicates whether the
disk has been formatted with protection information.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

block: Clean up the code used to generate and verify integrity metadata

2014-09-27T15:14:51+00:00

Instead of the "operate" parameter we pass in a seed value and a pointer
to a function that can be used to process the integrity metadata. The
generation function is changed to have a return value to fit into this
scheme.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

block: Deprecate the use of the term sector in the context of block integrity

2014-09-27T15:14:50+00:00

The protection interval is not necessarily tied to the logical block
size of a block device. Stop using the terms "sector" and "sectors".

Going forward we will use the term "seed" to describe the initial
reference tag value for a given I/O. "Interval" will be used to describe
the portion of the data buffer that a given piece of protection
information is associated with.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

block: Remove integrity tagging functions

2014-09-27T15:14:50+00:00

None of the filesystems appear interested in using the integrity tagging
feature. Potentially because very few storage devices actually permit
using the application tag space.

Remove the tagging functions.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

block: Replace bi_integrity with bi_special

2014-09-27T15:14:46+00:00

For commands like REQ_COPY we need a way to pass extra information along
with each bio. Like integrity metadata this information must be
available at the bottom of the stack so bi_private does not suffice.

Rename the existing bi_integrity field to bi_special and make it a union
so we can have different bio extensions for each class of command.

We previously used bi_integrity != NULL as a way to identify whether a
bio had integrity metadata or not. Introduce a REQ_INTEGRITY to be the
indicator now that bi_special can contain different things.

In addition, bio_integrity(bio) will now return a pointer to the
integrity payload (when applicable).

Signed-off-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Jens Axboe