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author | Tom Peng <tom_peng@usish.com> | 2009-07-01 20:37:26 +0800 |
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committer | James Bottomley <James.Bottomley@HansenPartnership.com> | 2009-07-16 12:50:44 -0500 |
commit | 5381837f125cc62ad703fbcdfcd7566fc81fd404 (patch) | |
tree | 872571a7a68dde3fd1f830c2d3ff62d5dbae3110 /drivers/scsi/libsas | |
parent | 35b5c55fee08e6e4001ba98060a2d0b82f70b5f4 (diff) | |
download | lwn-5381837f125cc62ad703fbcdfcd7566fc81fd404.tar.gz lwn-5381837f125cc62ad703fbcdfcd7566fc81fd404.zip |
[SCSI] libsas: reuse the original port when hotplugging phys in wide ports
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>
Diffstat (limited to 'drivers/scsi/libsas')
-rw-r--r-- | drivers/scsi/libsas/sas_port.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c index e6ac59c023f1..fe8b74c706d2 100644 --- a/drivers/scsi/libsas/sas_port.c +++ b/drivers/scsi/libsas/sas_port.c @@ -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", |