libata: implement on-demand HPA unlocking

Implement ata_scsi_unlock_native_capacity() which will be called through SCSI layer when block layer notices that partitions on a device extend beyond the end of the device. It requests EH to unlock HPA, waits for completion and returns the current device capacity. This allows libata to unlock HPA on demand instead of having to decide whether to unlock upfront. Unlocking on demand is safer than unlocking by upfront because some BIOSes write private data to the area beyond HPA limit. This was suggested by Ben Hutchings. Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

libata: implement on-demand HPA unlocking
Implement ata_scsi_unlock_native_capacity() which will be called through SCSI layer when block layer notices that partitions on a device extend beyond the end of the device. It requests EH to unlock HPA, waits for completion and returns the current device capacity. This allows libata to unlock HPA on demand instead of having to decide whether to unlock upfront. Unlocking on demand is safer than unlocking by upfront because some BIOSes write private data to the area beyond HPA limit. This was suggested by Ben Hutchings. Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Tejun Heo · Jeff Garzik
1 parent 68939ce5fc
Showing 3 changed files with 32 additions and 0 deletions Side-by-side Diff
drivers/ata/libata-core.c
drivers/ata/libata-scsi.c
include/linux/libata.h
@@ -6668,6 +6668,7 @@
 EXPORT_SYMBOL_GPL(ata_link_next);
 EXPORT_SYMBOL_GPL(ata_dev_next);
 EXPORT_SYMBOL_GPL(ata_std_bios_param);
+EXPORT_SYMBOL_GPL(ata_scsi_unlock_native_capacity);
 EXPORT_SYMBOL_GPL(ata_host_init);
 EXPORT_SYMBOL_GPL(ata_host_alloc);
 EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
@@ -415,6 +415,35 @@
 }
  
 /**
+ *	ata_scsi_unlock_native_capacity - unlock native capacity
+ *	@sdev: SCSI device to adjust device capacity for
+ *
+ *	This function is called if a partition on @sdev extends beyond
+ *	the end of the device.  It requests EH to unlock HPA.
+ *
+ *	LOCKING:
+ *	Defined by the SCSI layer.  Might sleep.
+ */
+void ata_scsi_unlock_native_capacity(struct scsi_device *sdev)
+{
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct ata_device *dev;
+	unsigned long flags;
+
+	spin_lock_irqsave(ap->lock, flags);
+
+	dev = ata_scsi_find_dev(ap, sdev);
+	if (dev && dev->n_sectors < dev->n_native_sectors) {
+		dev->flags |= ATA_DFLAG_UNLOCK_HPA;
+		dev->link->eh_info.action |= ATA_EH_RESET;
+		ata_port_schedule_eh(ap);
+	}
+
+	spin_unlock_irqrestore(ap->lock, flags);
+	ata_port_wait_eh(ap);
+}
+
+/**
  *	ata_get_identity - Handler for HDIO_GET_IDENTITY ioctl
  *	@ap: target port
  *	@sdev: SCSI device to get identify data for
@@ -1023,6 +1023,7 @@
 extern int ata_std_bios_param(struct scsi_device *sdev,
 			      struct block_device *bdev,
 			      sector_t capacity, int geom[]);
+extern void ata_scsi_unlock_native_capacity(struct scsi_device *sdev);
 extern int ata_scsi_slave_config(struct scsi_device *sdev);
 extern void ata_scsi_slave_destroy(struct scsi_device *sdev);
 extern int ata_scsi_change_queue_depth(struct scsi_device *sdev,
@@ -1174,6 +1175,7 @@
 	.slave_configure	= ata_scsi_slave_config,	\
 	.slave_destroy		= ata_scsi_slave_destroy,	\
 	.bios_param		= ata_std_bios_param,		\
+	.unlock_native_capacity	= ata_scsi_unlock_native_capacity, \
 	.sdev_attrs		= ata_common_sdev_attrs
  
 #define ATA_NCQ_SHT(drv_name)					\
...	...	@@ -6668,6 +6668,7 @@
6668	6668	EXPORT_SYMBOL_GPL(ata_link_next);
6669	6669	EXPORT_SYMBOL_GPL(ata_dev_next);
6670	6670	EXPORT_SYMBOL_GPL(ata_std_bios_param);
	6671	+EXPORT_SYMBOL_GPL(ata_scsi_unlock_native_capacity);
6671	6672	EXPORT_SYMBOL_GPL(ata_host_init);
6672	6673	EXPORT_SYMBOL_GPL(ata_host_alloc);
6673	6674	EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
...	...	@@ -415,6 +415,35 @@
415	415	}
416	416
417	417	/**
	418	+ * ata_scsi_unlock_native_capacity - unlock native capacity
	419	+ * @sdev: SCSI device to adjust device capacity for
	420	+ *
	421	+ * This function is called if a partition on @sdev extends beyond
	422	+ * the end of the device. It requests EH to unlock HPA.
	423	+ *
	424	+ * LOCKING:
	425	+ * Defined by the SCSI layer. Might sleep.
	426	+ */
	427	+void ata_scsi_unlock_native_capacity(struct scsi_device *sdev)
	428	+{
	429	+ struct ata_port *ap = ata_shost_to_port(sdev->host);
	430	+ struct ata_device *dev;
	431	+ unsigned long flags;
	432	+
	433	+ spin_lock_irqsave(ap->lock, flags);
	434	+
	435	+ dev = ata_scsi_find_dev(ap, sdev);
	436	+ if (dev && dev->n_sectors < dev->n_native_sectors) {
	437	+ dev->flags \|= ATA_DFLAG_UNLOCK_HPA;
	438	+ dev->link->eh_info.action \|= ATA_EH_RESET;
	439	+ ata_port_schedule_eh(ap);
	440	+ }
	441	+
	442	+ spin_unlock_irqrestore(ap->lock, flags);
	443	+ ata_port_wait_eh(ap);
	444	+}
	445	+
	446	+/**
418	447	* ata_get_identity - Handler for HDIO_GET_IDENTITY ioctl
419	448	* @ap: target port
420	449	* @sdev: SCSI device to get identify data for
...	...	@@ -1023,6 +1023,7 @@
1023	1023	extern int ata_std_bios_param(struct scsi_device *sdev,
1024	1024	struct block_device *bdev,
1025	1025	sector_t capacity, int geom[]);
	1026	+extern void ata_scsi_unlock_native_capacity(struct scsi_device *sdev);
1026	1027	extern int ata_scsi_slave_config(struct scsi_device *sdev);
1027	1028	extern void ata_scsi_slave_destroy(struct scsi_device *sdev);
1028	1029	extern int ata_scsi_change_queue_depth(struct scsi_device *sdev,
...	...	@@ -1174,6 +1175,7 @@
1174	1175	.slave_configure = ata_scsi_slave_config, \
1175	1176	.slave_destroy = ata_scsi_slave_destroy, \
1176	1177	.bios_param = ata_std_bios_param, \
	1178	+ .unlock_native_capacity = ata_scsi_unlock_native_capacity, \
1177	1179	.sdev_attrs = ata_common_sdev_attrs
1178	1180
1179	1181	#define ATA_NCQ_SHT(drv_name) \