[PATCH v6 0/5] scsi: Refresh INQUIRY data and reprobe on rescan

[Brian Bunker <brian@purestorage.com>]

This series teaches the SCSI rescan path to refetch standard INQUIRY data
and reprobe the device when the peripheral qualifier or device type has
changed.  The motivating case is an ALUA target that transitions through
the "unavailable" state and afterwards reports a different peripheral
qualifier; today the kernel keeps the stale INQUIRY data and the device's
sysfs attributes diverge from what the target reports.

  1/5 serializes the INQUIRY-derived sysfs attributes under
      sdev->inquiry_mutex so a concurrent reprobe cannot tear the read.
  2/5 adds scsi_update_inquiry_data() as the single point that copies a
      freshly-fetched INQUIRY buffer into sdev and updates derived fields.
      Returns SCSI_INQ_REPROBE_NEEDED only when peripheral qualifier or
      device type changes, as these are the only fields that determine
      driver binding.
  3/5 refactors scsi_add_lun() to use scsi_update_inquiry_data(), sharing
      one implementation between initial-probe and reprobe paths.
  4/5 teaches scsi_rescan_device() to refetch INQUIRY and reprobe the
      device when scsi_update_inquiry_data() reports a change.
  5/5 wires the same path into scsi_probe_and_add_lun() so existing
      devices encountered during a SCAN_LUNS pass get refreshed.

Changes since v5:
  - v5 was applied to 7.3/scsi-staging but did not make it into
    7.3/scsi-queue. This version is a rebase onto 7.4/scsi-staging
    with no functional changes.
  - 2/5: Resolved a context conflict in include/scsi/scsi_device.h
    with the removal of the scsi_device_from_queue() export.
  - 5/5: Resolved a context conflict in scsi_probe_and_add_lun() with
    "scsi: core: Pass the SCSI host pointer directly to scanning
    functions"; shost is now a function parameter, so the local
    shost declaration is dropped.
  - Build-tested with gcc W=1 and with clang 23 with
    CONFIG_WARN_CONTEXT_ANALYSIS=y; no new warnings.
  - All patches carry Reviewed-by: Hannes Reinecke from v5.

v5 cover-letter Message-ID: <20260618233508.97960-1-brian@purestorage.com>
v4 cover-letter Message-ID: <20260530002019.47109-1-brian@purestorage.com>
v3 cover-letter Message-ID: <20260429224939.77082-1-brian@purestorage.com>
v2 cover-letter Message-ID: <20260429012733.40855-1-brian@purestorage.com>
v1 cover-letter Message-ID: <20260424215324.99045-1-brian@purestorage.com>

Brian Bunker (5):
  scsi: core: Protect INQUIRY sysfs attributes with mutex
  scsi: core: Add scsi_update_inquiry_data() for updating INQUIRY data
  scsi: core: Refactor scsi_add_lun() to use scsi_update_inquiry_data()
  scsi: core: Add device reprobe support to scsi_rescan_device()
  scsi: core: Handle reprobe for existing devices during SCSI scan

 drivers/scsi/scsi.c        | 178 +++++++++++++++++++
 drivers/scsi/scsi_scan.c   | 353 +++++++++++++++++++++++++------------
 drivers/scsi/scsi_sysfs.c  |  28 ++-
 include/scsi/scsi_device.h |  13 ++
 4 files changed, 447 insertions(+), 125 deletions(-)


base-commit: 2f4880c22e838d54eae9ab153b0f8dce60531bf1
-- 
2.55.0