[Bug 218572] pass(4) driver sometimes does error recovery when CAM_PASS_ERR_RECOVER is not set

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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=218572

--- Comment #4 from commit-hook at freebsd.org ---
A commit references this bug:

Author: ken
Date: Wed May 10 15:20:40 UTC 2017
New revision: 318140
URL: https://svnweb.freebsd.org/changeset/base/318140

Log:
  MFC r317775:

    Fix error recovery behavior in the pass(4) driver.

    After FreeBSD SVN revision 236814, the pass(4) driver changed from
    only doing error recovery when the CAM_PASS_ERR_RECOVER flag was
    set on a CCB to sometimes doing error recovery if the passed in
    retry count was non-zero.

    Error recovery would happen if two conditions were met:

    1.  The error recovery action was simply a retry.  (Which is most
        cases.)
    2.  The retry_count is non-zero. (Which happened a lot because of
        cut-and-pasted code.)

    This explains a bug I noticed in with camcontrol:

    # camcontrol tur da34 -v
    Unit is ready
    # camcontrol reset da34
    Reset of 1:172:0 was successful

    At this point, there should be a Unit Attention:

    # camcontrol tur da34 -v
    Unit is ready

    No Unit Attention.

    Try it again:

    # camcontrol reset da34
    Reset of 1:172:0 was successful

    Now set the retry_count to 0 for the TUR:

    # camcontrol tur da34 -v -C 0
    Unit is not ready
    (pass42:mps1:0:172:0): TEST UNIT READY. CDB: 00 00 00 00 00 00
    (pass42:mps1:0:172:0): CAM status: SCSI Status Error
    (pass42:mps1:0:172:0): SCSI status: Check Condition
    (pass42:mps1:0:172:0): SCSI sense: UNIT ATTENTION asc:29,2 (SCSI bus reset
    occurred)
    (pass42:mps1:0:172:0): Field Replaceable Unit: 2

    There is the unit attention. camcontrol(8) has a default
    retry_count of 1, in case someone sets the -E flag without
    setting -C.

    The CAM_PASS_ERR_RECOVER behavior was only broken with the
    CAMIOCOMMAND ioctl, which is the synchronous pass(4) API.  It has
    worked as intended (error recovery is only done when the flag
    is set) in the asynchronous API (CAMIOQUEUE ioctl).

    sys/cam/scsi/scsi_pass.c:
        In passsendccb(), when calling cam_periph_runccb(), only
        specify the error routine when CAM_PASS_ERR_RECOVER is set.

    share/man/man4/pass.4:
        Document that CAM_PASS_ERR_RECOVER is needed to enable
        error recovery.

  Reported by:  Terry Kennedy <TERRY at glaver.org>
  PR:           kern/218572
  Sponsored by: Spectra Logic

Changes:
_U  stable/10/
  stable/10/share/man/man4/pass.4
  stable/10/sys/cam/scsi/scsi_pass.c

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