[PATCH v3 0/1] scsi: scsi_dh_alua: increase default ALUA timeout to maximum spec value

[Brian Bunker <brian@purestorage.com>]

The ALUA handler already maps a 0 value (no implicit transition timeout
provided by the target) to the ALUA_FAILOVER_TIMEOUT constant. This
means the kernel is already saying it won't accept an infinite
transition time - it substitutes a finite default instead.

It has been suggested that some arrays may take tens of minutes to
complete transitions, but even today those would be broken by the
current 0-to-60-second translation. The kernel currently caps this.

The SCSI specification allows the implicit transition timeout to be
specified as a single byte, meaning the maximum explicit value is 255
seconds. This patch simply changes the default from an arbitrary 60
seconds to U8_MAX (255), the highest value that could be explicitly
provided by the target per the spec.

This is a minimal, safe change: we're not removing the cap, just
raising the default to match what the spec allows.

Brian Bunker (1):
  scsi: scsi_dh_alua: increase default ALUA timeout to maximum spec
    value

 drivers/scsi/device_handler/scsi_dh_alua.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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2.50.1 (Apple Git-155)