libata: allocate ap separately from shost

Don't embed ap inside shost.  Allocate it separately and point it back
from shosts's hostdata.  This makes port allocation more flexible and
allows regular ATA and SAS share host alloc/init paths.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 15 insertions, 6 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index f368387829ca..c831c9efee60 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5792,13 +5792,18 @@ static struct ata_port * ata_port_add(const struct ata_probe_ent *ent,
                 return NULL;
         }
 
-        shost = scsi_host_alloc(ent->sht, sizeof(struct ata_port));
-        if (!shost)
+        ap = kzalloc(sizeof(struct ata_port), GFP_KERNEL);
+        if (!ap)
                 return NULL;
 
-        shost->transportt = &ata_scsi_transport_template;
+        shost = scsi_host_alloc(ent->sht, sizeof(struct ata_port *));
+        if (!shost) {
+                kfree(ap);
+                return NULL;
+        }
 
-        ap = ata_shost_to_port(shost);
+        *(struct ata_port **)&shost->hostdata[0] = ap;
+        shost->transportt = &ata_scsi_transport_template;
 
         ata_port_init(ap, host, ent, port_no);
         ata_port_init_shost(ap, shost);
@@ -5824,9 +5829,13 @@ static void ata_host_release(struct device *gendev, void *res)
         for (i = 0; i < host->n_ports; i++) {
                 struct ata_port *ap = host->ports[i];
 
-                if (ap)
+                if (!ap)
+                        continue;
+
+                if (ap->scsi_host)
                         scsi_host_put(ap->scsi_host);
 
+                kfree(ap);
                 host->ports[i] = NULL;
         }
 
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 12237d4b9f9b..ced9dd54035e 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1231,7 +1231,7 @@ static inline void ata_pad_free(struct ata_port *ap, struct device *dev)
 
 static inline struct ata_port *ata_shost_to_port(struct Scsi_Host *host)
 {
-        return (struct ata_port *) &host->hostdata[0];
+        return *(struct ata_port **)&host->hostdata[0];
 }
 
 #endif /* __LINUX_LIBATA_H__ */