[PATCH v4 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 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)