[PATCH] libata-hp: update unload-unplug

Update unload unplug - driver unloading / PCI removal. This is done by ata_port_detach() which short-circuits EH, disables all devices and freezes the port. With this patch, EH and unloading/unplugging are properly synchronized. Signed-off-by: Tejun Heo <htejun@gmail.com>

[PATCH] libata-hp: update unload-unplug
Update unload unplug - driver unloading / PCI removal. This is done by ata_port_detach() which short-circuits EH, disables all devices and freezes the port. With this patch, EH and unloading/unplugging are properly synchronized. Signed-off-by: Tejun Heo <htejun@gmail.com>
Tejun Heo
1 parent 3e706399b0
Showing 4 changed files with 71 additions and 15 deletions Side-by-side Diff
drivers/scsi/ahci.c
drivers/scsi/libata-core.c
drivers/scsi/libata-eh.c
include/linux/libata.h
@@ -1389,21 +1389,17 @@
 	struct device *dev = pci_dev_to_dev(pdev);
 	struct ata_host_set *host_set = dev_get_drvdata(dev);
 	struct ahci_host_priv *hpriv = host_set->private_data;
-	struct ata_port *ap;
 	unsigned int i;
 	int have_msi;
  
-	for (i = 0; i < host_set->n_ports; i++) {
-		ap = host_set->ports[i];
+	for (i = 0; i < host_set->n_ports; i++)
+		ata_port_detach(host_set->ports[i]);
  
-		scsi_remove_host(ap->host);
-	}
-
 	have_msi = hpriv->flags & AHCI_FLAG_MSI;
 	free_irq(host_set->irq, host_set);
  
 	for (i = 0; i < host_set->n_ports; i++) {
-		ap = host_set->ports[i];
+		struct ata_port *ap = host_set->ports[i];
  
 		ata_scsi_release(ap->host);
 		scsi_host_put(ap->host);
@@ -5610,6 +5610,63 @@
 }
  
 /**
+ *	ata_port_detach - Detach ATA port in prepration of device removal
+ *	@ap: ATA port to be detached
+ *
+ *	Detach all ATA devices and the associated SCSI devices of @ap;
+ *	then, remove the associated SCSI host.  @ap is guaranteed to
+ *	be quiescent on return from this function.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ */
+void ata_port_detach(struct ata_port *ap)
+{
+	unsigned long flags;
+	int i;
+
+	if (!ap->ops->error_handler)
+		return;
+
+	/* tell EH we're leaving & flush EH */
+	spin_lock_irqsave(&ap->host_set->lock, flags);
+	ap->flags |= ATA_FLAG_UNLOADING;
+	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+	ata_port_wait_eh(ap);
+
+	/* EH is now guaranteed to see UNLOADING, so no new device
+	 * will be attached.  Disable all existing devices.
+	 */
+	spin_lock_irqsave(&ap->host_set->lock, flags);
+
+	for (i = 0; i < ATA_MAX_DEVICES; i++)
+		ata_dev_disable(&ap->device[i]);
+
+	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+	/* Final freeze & EH.  All in-flight commands are aborted.  EH
+	 * will be skipped and retrials will be terminated with bad
+	 * target.
+	 */
+	spin_lock_irqsave(&ap->host_set->lock, flags);
+	ata_port_freeze(ap);	/* won't be thawed */
+	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+	ata_port_wait_eh(ap);
+
+	/* Flush hotplug task.  The sequence is similar to
+	 * ata_port_flush_task().
+	 */
+	flush_workqueue(ata_aux_wq);
+	cancel_delayed_work(&ap->hotplug_task);
+	flush_workqueue(ata_aux_wq);
+
+	/* remove the associated SCSI host */
+	scsi_remove_host(ap->host);
+}
+
+/**
  *	ata_host_set_remove - PCI layer callback for device removal
  *	@host_set: ATA host set that was removed
  *
  
  
@@ -5622,18 +5679,15 @@
  
 void ata_host_set_remove(struct ata_host_set *host_set)
 {
-	struct ata_port *ap;
 	unsigned int i;
  
-	for (i = 0; i < host_set->n_ports; i++) {
-		ap = host_set->ports[i];
-		scsi_remove_host(ap->host);
-	}
+	for (i = 0; i < host_set->n_ports; i++)
+		ata_port_detach(host_set->ports[i]);
  
 	free_irq(host_set->irq, host_set);
  
 	for (i = 0; i < host_set->n_ports; i++) {
-		ap = host_set->ports[i];
+		struct ata_port *ap = host_set->ports[i];
  
 		ata_scsi_release(ap->host);
  
@@ -5901,6 +5955,7 @@
 EXPORT_SYMBOL_GPL(ata_std_bios_param);
 EXPORT_SYMBOL_GPL(ata_std_ports);
 EXPORT_SYMBOL_GPL(ata_device_add);
+EXPORT_SYMBOL_GPL(ata_port_detach);
 EXPORT_SYMBOL_GPL(ata_host_set_remove);
 EXPORT_SYMBOL_GPL(ata_sg_init);
 EXPORT_SYMBOL_GPL(ata_sg_init_one);
@@ -46,6 +46,7 @@
 #include "libata.h"
  
 static void __ata_port_freeze(struct ata_port *ap);
+static void ata_eh_finish(struct ata_port *ap);
  
 static void ata_ering_record(struct ata_ering *ering, int is_io,
 			     unsigned int err_mask)
@@ -242,8 +243,11 @@
  
 		spin_unlock_irqrestore(hs_lock, flags);
  
-		/* invoke EH */
-		ap->ops->error_handler(ap);
+		/* invoke EH.  if unloading, just finish failed qcs */
+		if (!(ap->flags & ATA_FLAG_UNLOADING))
+			ap->ops->error_handler(ap);
+		else
+			ata_eh_finish(ap);
  
 		/* Exception might have happend after ->error_handler
 		 * recovered the port but before this point.  Repeat
@@ -649,6 +649,7 @@
 extern int ata_pci_clear_simplex(struct pci_dev *pdev);
 #endif /* CONFIG_PCI */
 extern int ata_device_add(const struct ata_probe_ent *ent);
+extern void ata_port_detach(struct ata_port *ap);
 extern void ata_host_set_remove(struct ata_host_set *host_set);
 extern int ata_scsi_detect(struct scsi_host_template *sht);
 extern int ata_scsi_ioctl(struct scsi_device *dev, int cmd, void __user *arg);
...	...	@@ -1389,21 +1389,17 @@
1389	1389	struct device *dev = pci_dev_to_dev(pdev);
1390	1390	struct ata_host_set *host_set = dev_get_drvdata(dev);
1391	1391	struct ahci_host_priv *hpriv = host_set->private_data;
1392		- struct ata_port *ap;
1393	1392	unsigned int i;
1394	1393	int have_msi;
1395	1394
1396		- for (i = 0; i < host_set->n_ports; i++) {
1397		- ap = host_set->ports[i];
	1395	+ for (i = 0; i < host_set->n_ports; i++)
	1396	+ ata_port_detach(host_set->ports[i]);
1398	1397
1399		- scsi_remove_host(ap->host);
1400		- }
1401		-
1402	1398	have_msi = hpriv->flags & AHCI_FLAG_MSI;
1403	1399	free_irq(host_set->irq, host_set);
1404	1400
1405	1401	for (i = 0; i < host_set->n_ports; i++) {
1406		- ap = host_set->ports[i];
	1402	+ struct ata_port *ap = host_set->ports[i];
1407	1403
1408	1404	ata_scsi_release(ap->host);
1409	1405	scsi_host_put(ap->host);
...	...	@@ -5610,6 +5610,63 @@
5610	5610	}
5611	5611
5612	5612	/**
	5613	+ * ata_port_detach - Detach ATA port in prepration of device removal
	5614	+ * @ap: ATA port to be detached
	5615	+ *
	5616	+ * Detach all ATA devices and the associated SCSI devices of @ap;
	5617	+ * then, remove the associated SCSI host. @ap is guaranteed to
	5618	+ * be quiescent on return from this function.
	5619	+ *
	5620	+ * LOCKING:
	5621	+ * Kernel thread context (may sleep).
	5622	+ */
	5623	+void ata_port_detach(struct ata_port *ap)
	5624	+{
	5625	+ unsigned long flags;
	5626	+ int i;
	5627	+
	5628	+ if (!ap->ops->error_handler)
	5629	+ return;
	5630	+
	5631	+ /* tell EH we're leaving & flush EH */
	5632	+ spin_lock_irqsave(&ap->host_set->lock, flags);
	5633	+ ap->flags \|= ATA_FLAG_UNLOADING;
	5634	+ spin_unlock_irqrestore(&ap->host_set->lock, flags);
	5635	+
	5636	+ ata_port_wait_eh(ap);
	5637	+
	5638	+ /* EH is now guaranteed to see UNLOADING, so no new device
	5639	+ * will be attached. Disable all existing devices.
	5640	+ */
	5641	+ spin_lock_irqsave(&ap->host_set->lock, flags);
	5642	+
	5643	+ for (i = 0; i < ATA_MAX_DEVICES; i++)
	5644	+ ata_dev_disable(&ap->device[i]);
	5645	+
	5646	+ spin_unlock_irqrestore(&ap->host_set->lock, flags);
	5647	+
	5648	+ /* Final freeze & EH. All in-flight commands are aborted. EH
	5649	+ * will be skipped and retrials will be terminated with bad
	5650	+ * target.
	5651	+ */
	5652	+ spin_lock_irqsave(&ap->host_set->lock, flags);
	5653	+ ata_port_freeze(ap); /* won't be thawed */
	5654	+ spin_unlock_irqrestore(&ap->host_set->lock, flags);
	5655	+
	5656	+ ata_port_wait_eh(ap);
	5657	+
	5658	+ /* Flush hotplug task. The sequence is similar to
	5659	+ * ata_port_flush_task().
	5660	+ */
	5661	+ flush_workqueue(ata_aux_wq);
	5662	+ cancel_delayed_work(&ap->hotplug_task);
	5663	+ flush_workqueue(ata_aux_wq);
	5664	+
	5665	+ /* remove the associated SCSI host */
	5666	+ scsi_remove_host(ap->host);
	5667	+}
	5668	+
	5669	+/**
5613	5670	* ata_host_set_remove - PCI layer callback for device removal
5614	5671	* @host_set: ATA host set that was removed
5615	5672	*
5616	5673
5617	5674
...	...	@@ -5622,18 +5679,15 @@
5622	5679
5623	5680	void ata_host_set_remove(struct ata_host_set *host_set)
5624	5681	{
5625		- struct ata_port *ap;
5626	5682	unsigned int i;
5627	5683
5628		- for (i = 0; i < host_set->n_ports; i++) {
5629		- ap = host_set->ports[i];
5630		- scsi_remove_host(ap->host);
5631		- }
	5684	+ for (i = 0; i < host_set->n_ports; i++)
	5685	+ ata_port_detach(host_set->ports[i]);
5632	5686
5633	5687	free_irq(host_set->irq, host_set);
5634	5688
5635	5689	for (i = 0; i < host_set->n_ports; i++) {
5636		- ap = host_set->ports[i];
	5690	+ struct ata_port *ap = host_set->ports[i];
5637	5691
5638	5692	ata_scsi_release(ap->host);
5639	5693
...	...	@@ -5901,6 +5955,7 @@
5901	5955	EXPORT_SYMBOL_GPL(ata_std_bios_param);
5902	5956	EXPORT_SYMBOL_GPL(ata_std_ports);
5903	5957	EXPORT_SYMBOL_GPL(ata_device_add);
	5958	+EXPORT_SYMBOL_GPL(ata_port_detach);
5904	5959	EXPORT_SYMBOL_GPL(ata_host_set_remove);
5905	5960	EXPORT_SYMBOL_GPL(ata_sg_init);
5906	5961	EXPORT_SYMBOL_GPL(ata_sg_init_one);
...	...	@@ -46,6 +46,7 @@
46	46	#include "libata.h"
47	47
48	48	static void __ata_port_freeze(struct ata_port *ap);
	49	+static void ata_eh_finish(struct ata_port *ap);
49	50
50	51	static void ata_ering_record(struct ata_ering *ering, int is_io,
51	52	unsigned int err_mask)
...	...	@@ -242,8 +243,11 @@
242	243
243	244	spin_unlock_irqrestore(hs_lock, flags);
244	245
245		- /* invoke EH */
246		- ap->ops->error_handler(ap);
	246	+ /* invoke EH. if unloading, just finish failed qcs */
	247	+ if (!(ap->flags & ATA_FLAG_UNLOADING))
	248	+ ap->ops->error_handler(ap);
	249	+ else
	250	+ ata_eh_finish(ap);
247	251
248	252	/* Exception might have happend after ->error_handler
249	253	* recovered the port but before this point. Repeat
...	...	@@ -649,6 +649,7 @@
649	649	extern int ata_pci_clear_simplex(struct pci_dev *pdev);
650	650	#endif /* CONFIG_PCI */
651	651	extern int ata_device_add(const struct ata_probe_ent *ent);
	652	+extern void ata_port_detach(struct ata_port *ap);
652	653	extern void ata_host_set_remove(struct ata_host_set *host_set);
653	654	extern int ata_scsi_detect(struct scsi_host_template *sht);
654	655	extern int ata_scsi_ioctl(struct scsi_device dev, int cmd, void __user arg);