[PATCH] libata: fix probe_ent alloc/free bugs

[Tejun Heo <htejun@gmail.com>]

ata_probe_ent_alloc() had a temporary hack such that devm_kzalloc()
was used for allocation if devres had been previously initialized on
the device; otherwise, plain kzalloc() was used.  This was to make the
code useable from both the old and devres-aware libata drivers during
transition.  This hack made ata_sas_port_alloc() unable to determine
how the probe_ent is allocated, causing double free in some cases.

Remove the now-unneeded hack and make ata_sas_port_alloc() use
devm_kfree().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
---
James, thanks for the diagnosis and please ack if this fixes the
problem.

Jeff, after James' ack, can you please verify this works with a libata
driver?  Just loading and unloading a libata LLD should be enough.
I'm visiting my hometown for lunar new year's day, so I can't do it
till Tuesday.

Thanks.

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2cf8251..c34e0b4 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5891,11 +5891,7 @@ ata_probe_ent_alloc(struct device *dev, const struct ata_port_info *port)
 {
 	struct ata_probe_ent *probe_ent;
 
-	/* XXX - the following if can go away once all LLDs are managed */
-	if (!list_empty(&dev->devres_head))
-		probe_ent = devm_kzalloc(dev, sizeof(*probe_ent), GFP_KERNEL);
-	else
-		probe_ent = kzalloc(sizeof(*probe_ent), GFP_KERNEL);
+	probe_ent = devm_kzalloc(dev, sizeof(*probe_ent), GFP_KERNEL);
 	if (!probe_ent) {
 		printk(KERN_ERR DRV_NAME "(%s): out of memory\n",
 		       kobject_name(&(dev->kobj)));
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 0009818..e5e19e3 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3234,7 +3234,7 @@ struct ata_port *ata_sas_port_alloc(struct ata_host *host,
 
 	ata_port_init(ap, host, ent, 0);
 	ap->lock = shost->host_lock;
-	kfree(ent);
+	devm_kfree(host->dev, ent);
 	return ap;
 }
 EXPORT_SYMBOL_GPL(ata_sas_port_alloc);