Fix: scsi: sd: Atomic write support added in 6.11-rc1

Fix: scsi: sd: Atomic write support added in 6.11-rc1

See upstream commit:

    commit bf4ae8f2e6407a779c0368eb0f3e047a8333be17
    Author: John Garry <john.g.garry@oracle.com>
    Date:   Thu Jun 20 12:53:57 2024 +0000

        scsi: sd: Atomic write support

        Support is divided into two main areas:
        - reading VPD pages and setting sdev request_queue limits
        - support WRITE ATOMIC (16) command and tracing

        The relevant block limits VPD page need to be read to allow the block layer
        request_queue atomic write limits to be set. These VPD page limits are
        described in sbc4r22 section 6.6.4 - Block limits VPD page.

        There are five limits of interest:
        - MAXIMUM ATOMIC TRANSFER LENGTH
        - ATOMIC ALIGNMENT
        - ATOMIC TRANSFER LENGTH GRANULARITY
        - MAXIMUM ATOMIC TRANSFER LENGTH WITH BOUNDARY
        - MAXIMUM ATOMIC BOUNDARY SIZE

        MAXIMUM ATOMIC TRANSFER LENGTH is the maximum length for a WRITE ATOMIC
        (16) command. It will not be greater than the device MAXIMUM TRANSFER
        LENGTH.

        ATOMIC ALIGNMENT and ATOMIC TRANSFER LENGTH GRANULARITY are the minimum
        alignment and length values for an atomic write in terms of logical blocks.

        Unlike NVMe, SCSI does not specify an LBA space boundary, but does specify
        a per-IO boundary granularity. The maximum boundary size is specified in
        MAXIMUM ATOMIC BOUNDARY SIZE. When used, this boundary value is set in the
        WRITE ATOMIC (16) ATOMIC BOUNDARY field - layout for the WRITE_ATOMIC_16
        command can be found in sbc4r22 section 5.48. This boundary value is the
        granularity size at which the device may atomically write the data. A value
        of zero in WRITE ATOMIC (16) ATOMIC BOUNDARY field means that all data must
        be atomically written together.

        MAXIMUM ATOMIC TRANSFER LENGTH WITH BOUNDARY is the maximum atomic write
        length if a non-zero boundary value is set.

        For atomic write support, the WRITE ATOMIC (16) boundary is not of much
        interest, as the block layer expects each request submitted to be executed
        be atomically written together.

        MAXIMUM ATOMIC TRANSFER LENGTH WITH BOUNDARY is the maximum atomic write
        length if a non-zero boundary value is set.

        For atomic write support, the WRITE ATOMIC (16) boundary is not of much
        interest, as the block layer expects each request submitted to be executed
        atomically. However, the SCSI spec does leave itself open to a quirky
        scenario where MAXIMUM ATOMIC TRANSFER LENGTH is zero, yet MAXIMUM ATOMIC
        TRANSFER LENGTH WITH BOUNDARY and MAXIMUM ATOMIC BOUNDARY SIZE are both
        non-zero. This case will be supported.

        To set the block layer request_queue atomic write capabilities, sanitize
        the VPD page limits and set limits as follows:
        - atomic_write_unit_min is derived from granularity and alignment values.
          If no granularity value is not set, use physical block size
        - atomic_write_unit_max is derived from MAXIMUM ATOMIC TRANSFER LENGTH. In
          the scenario where MAXIMUM ATOMIC TRANSFER LENGTH is zero and boundary
          limits are non-zero, use MAXIMUM ATOMIC BOUNDARY SIZE for
          atomic_write_unit_max. New flag scsi_disk.use_atomic_write_boundary is
          set for this scenario.
        - atomic_write_boundary_bytes is set to zero always

        SCSI also supports a WRITE ATOMIC (32) command, which is for type 2
        protection enabled. This is not going to be supported now, so check for
        T10_PI_TYPE2_PROTECTION when setting any request_queue limits.

        To handle an atomic write request, add support for WRITE ATOMIC (16)
        command in handler sd_setup_atomic_cmnd(). Flag use_atomic_write_boundary
        is checked here for encoding ATOMIC BOUNDARY field.

        Trace info is also added for WRITE_ATOMIC_16 command.

Change-Id: Ie072002fe2184615c72531ac081a324ef18cfb03
Signed-off-by: Kienan Stewart <kstewart@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>