Implement unload unplug - driver unloading / PCI removal via hot
unplug path. This is done by ata_port_detach() which requests detach
of all devices, schedules EH and wait for it to complete. EH path is
slightly modified to handle this (e.g. force zero eh_info during
unloading). With this patch, EH and unloading are properly
synchronized and unloading should be safe under any circumstances.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/scsi/ahci.c | 10 ++-----
drivers/scsi/libata-core.c | 59 ++++++++++++++++++++++++++++++++++++++++----
drivers/scsi/libata-eh.c | 7 +++--
include/linux/libata.h | 1 +
4 files changed, 61 insertions(+), 16 deletions(-)
dc54139a72085d78f1fc35a721cff16cdeb38ef9
diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index afb3805..60f455b 100644
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -1389,21 +1389,17 @@ static void ahci_remove_one (struct pci_
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];
-
- scsi_remove_host(ap->host);
- }
+ for (i = 0; i < host_set->n_ports; i++)
+ ata_port_detach(host_set->ports[i]);
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);
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index f45e04f..b622c61 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -5613,6 +5613,55 @@ err_free_ret:
}
/**
+ * 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 to self-destruct */
+ spin_lock_irqsave(&ap->host_set->lock, flags);
+
+ ap->flags |= ATA_FLAG_UNLOADING;
+ for (i = 0; i < ATA_MAX_DEVICES; i++)
+ ap->device[i].flags |= ATA_DFLAG_DETACH;
+
+ ata_port_schedule_eh(ap);
+
+ spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+ /* wait for EH */
+ while (scsi_host_in_recovery(ap->host))
+ msleep(100);
+
+ /* Flush hotplug task. The sequence is similar to
+ * ata_port_flush_task(). ATA_FLAG_UNLOADING prevents further
+ * queueing of hotplug_task.
+ */
+ flush_workqueue(ata_scsi_wq);
+ cancel_delayed_work(&ap->hotplug_task);
+ flush_workqueue(ata_scsi_wq);
+
+ /* freeze the port */
+ ata_eh_freeze_port(ap);
+
+ /* 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
*
@@ -5625,18 +5674,15 @@ err_free_ret:
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);
@@ -5904,6 +5950,7 @@ EXPORT_SYMBOL_GPL(sata_deb_timing_before
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);
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 7b5cb02..9eb73bb 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -234,7 +234,8 @@ void ata_scsi_error(struct Scsi_Host *ho
spin_lock_irqsave(hs_lock, flags);
memset(&ap->eh_context, 0, sizeof(ap->eh_context));
- ap->eh_context.i = ap->eh_info;
+ if (!(ap->flags & ATA_FLAG_UNLOADING))
+ ap->eh_context.i = ap->eh_info;
memset(&ap->eh_info, 0, sizeof(ap->eh_info));
ap->flags &= ~ATA_FLAG_EH_PENDING;
@@ -290,7 +291,7 @@ void ata_scsi_error(struct Scsi_Host *ho
int bit = fls(ATA_FLAG_LOADING) - 1;
clear_bit(bit, &ap->flags);
wake_up_bit(&ap->flags, bit);
- } else {
+ } else if (!(ap->flags & ATA_FLAG_UNLOADING)) {
if (ap->flags & ATA_FLAG_SCSI_HOTPLUG)
queue_work(ata_scsi_wq, &ap->hotplug_task);
if (ap->flags & ATA_FLAG_RECOVERED)
@@ -1769,7 +1770,7 @@ void ata_do_eh(struct ata_port *ap, ata_
ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
ata_postreset_fn_t postreset)
{
- if (!(ap->flags & ATA_FLAG_LOADING)) {
+ if (!(ap->flags & (ATA_FLAG_LOADING | ATA_FLAG_UNLOADING))) {
ata_eh_autopsy(ap);
ata_eh_report(ap);
}
diff --git a/include/linux/libata.h b/include/linux/libata.h
index b216400..99a2b68 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -647,6 +647,7 @@ extern int ata_pci_device_resume(struct
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);
--
1.3.2
-
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