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[SCSI] libsas: reuse the original port when hotplugging phys in wide ports

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There's a hotplug problem in the way libsas allocates ports: it loops over the
available ports first trying to add to an existing for a wide port and
otherwise allocating the next free port.  This scheme only works if the port
array is packed from zero, which fails if a port gets hot unplugged and the
array becomes sparse.  In that case, a new port is formed even if there's a
wide port it should be part of.  Fix this by creating two loops over all the
ports:  the first to see if the phy should be part of a wide port and the
second to form a new port in an empty port slot.

Signed-off-by: Tom Peng <tom_peng@usish.com>
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Lindar Liu <lindar_liu@usish.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Tom Peng 2009-07-01 20:37:26 +08:00 committed by James Bottomley
parent 35b5c55fee
commit 5381837f12
1 changed files with 15 additions and 4 deletions
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19
drivers/scsi/libsas/sas_port.c
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@ -56,7 +56,7 @@ static void sas_form_port(struct asd_sas_phy *phy)
}
}
/* find a port */
/* see if the phy should be part of a wide port */
spin_lock_irqsave(&sas_ha->phy_port_lock, flags);
for (i = 0; i < sas_ha->num_phys; i++) {
port = sas_ha->sas_port[i];
@ -69,12 +69,23 @@ static void sas_form_port(struct asd_sas_phy *phy)
SAS_DPRINTK("phy%d matched wide port%d\n", phy->id,
port->id);
break;
} else if (*(u64 *) port->sas_addr == 0 && port->num_phys==0) {
memcpy(port->sas_addr, phy->sas_addr, SAS_ADDR_SIZE);
break;
}
spin_unlock(&port->phy_list_lock);
}
/* The phy does not match any existing port, create a new one */
if (i == sas_ha->num_phys) {
for (i = 0; i < sas_ha->num_phys; i++) {
port = sas_ha->sas_port[i];
spin_lock(&port->phy_list_lock);
if (*(u64 *)port->sas_addr == 0
&& port->num_phys == 0) {
memcpy(port->sas_addr, phy->sas_addr,
SAS_ADDR_SIZE);
break;
}
spin_unlock(&port->phy_list_lock);
}
}
if (i >= sas_ha->num_phys) {
printk(KERN_NOTICE "%s: couldn't find a free port, bug?\n",