[SCSI] libsas, libata: fix start of life for a sas ata_port

This changes the ordering of initialization and probing events from:
  1/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
  2/ allocate ata_port and schedule port probe in DISCE_PROBE
...to:
  1/ allocate ata_port in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
  2/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
  3/ schedule port probe in DISCE_PROBE

This ordering prevents PHYE_SIGNAL_LOSS_EVENTS from sneaking in to
destrory ata devices before they have been fully initialized:

  BUG: unable to handle kernel paging request at 0000000000003b10
  IP: [<ffffffffa0053d7e>] sas_ata_end_eh+0x12/0x5e [libsas]
  ...
  [<ffffffffa004d1af>] sas_unregister_common_dev+0x78/0xc9 [libsas]
  [<ffffffffa004d4d4>] sas_unregister_dev+0x4f/0xad [libsas]
  [<ffffffffa004d5b1>] sas_unregister_domain_devices+0x7f/0xbf [libsas]
  [<ffffffffa004c487>] sas_deform_port+0x61/0x1b8 [libsas]
  [<ffffffffa004bed0>] sas_phye_loss_of_signal+0x29/0x2b [libsas]

...and kills the awkward "sata domain_device briefly existing in the
domain without an ata_port" state.

Reported-by: Michal Kosciowski <michal.kosciowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 7832b1a..2222635 100644 (file)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3839,18 +3839,25 @@ void ata_sas_port_stop(struct ata_port *ap)
 }
 EXPORT_SYMBOL_GPL(ata_sas_port_stop);
 
-int ata_sas_async_port_init(struct ata_port *ap)
+/**
+ * ata_sas_async_probe - simply schedule probing and return
+ * @ap: Port to probe
+ *
+ * For batch scheduling of probe for sas attached ata devices, assumes
+ * the port has already been through ata_sas_port_init()
+ */
+void ata_sas_async_probe(struct ata_port *ap)
 {
-       int rc = ap->ops->port_start(ap);
-
-       if (!rc) {
-               ap->print_id = atomic_inc_return(&ata_print_id);
-               __ata_port_probe(ap);
-       }
+       __ata_port_probe(ap);
+}
+EXPORT_SYMBOL_GPL(ata_sas_async_probe);
 
-       return rc;
+int ata_sas_sync_probe(struct ata_port *ap)
+{
+       return ata_port_probe(ap);
 }
-EXPORT_SYMBOL_GPL(ata_sas_async_port_init);
+EXPORT_SYMBOL_GPL(ata_sas_sync_probe);
+
 
 /**
  *     ata_sas_port_init - Initialize a SATA device
@@ -3867,12 +3874,10 @@ int ata_sas_port_init(struct ata_port *ap)
 {
        int rc = ap->ops->port_start(ap);
 
-       if (!rc) {
-               ap->print_id = atomic_inc_return(&ata_print_id);
-               rc = ata_port_probe(ap);
-       }
-
-       return rc;
+       if (rc)
+               return rc;
+       ap->print_id = atomic_inc_return(&ata_print_id);
+       return 0;
 }
 EXPORT_SYMBOL_GPL(ata_sas_port_init);
 

diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index e002cd4..467dc38 100644 (file)
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -4549,8 +4549,12 @@ static int ipr_ata_slave_alloc(struct scsi_device *sdev)
        ENTER;
        if (sdev->sdev_target)
                sata_port = sdev->sdev_target->hostdata;
-       if (sata_port)
+       if (sata_port) {
                rc = ata_sas_port_init(sata_port->ap);
+               if (rc == 0)
+                       rc = ata_sas_sync_probe(sata_port->ap);
+       }
+
        if (rc)
                ipr_slave_destroy(sdev);
 

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index bc0cecc..441d88a 100644 (file)
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -546,11 +546,12 @@ static struct ata_port_info sata_port_info = {
        .port_ops = &sas_sata_ops
 };
 
-int sas_ata_init_host_and_port(struct domain_device *found_dev)
+int sas_ata_init(struct domain_device *found_dev)
 {
        struct sas_ha_struct *ha = found_dev->port->ha;
        struct Scsi_Host *shost = ha->core.shost;
        struct ata_port *ap;
+       int rc;
 
        ata_host_init(&found_dev->sata_dev.ata_host,
                      ha->dev,
@@ -567,8 +568,11 @@ int sas_ata_init_host_and_port(struct domain_device *found_dev)
        ap->private_data = found_dev;
        ap->cbl = ATA_CBL_SATA;
        ap->scsi_host = shost;
-       /* publish initialized ata port */
-       smp_wmb();
+       rc = ata_sas_port_init(ap);
+       if (rc) {
+               ata_sas_port_destroy(ap);
+               return rc;
+       }
        found_dev->sata_dev.ap = ap;
 
        return 0;
@@ -648,18 +652,13 @@ static void sas_get_ata_command_set(struct domain_device *dev)
 void sas_probe_sata(struct asd_sas_port *port)
 {
        struct domain_device *dev, *n;
-       int err;
 
        mutex_lock(&port->ha->disco_mutex);
-       list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
+       list_for_each_entry(dev, &port->disco_list, disco_list_node) {
                if (!dev_is_sata(dev))
                        continue;
 
-               err = sas_ata_init_host_and_port(dev);
-               if (err)
-                       sas_fail_probe(dev, __func__, err);
-               else
-                       ata_sas_async_port_init(dev->sata_dev.ap);
+               ata_sas_async_probe(dev->sata_dev.ap);
        }
        mutex_unlock(&port->ha->disco_mutex);
 
@@ -718,18 +717,6 @@ static void async_sas_ata_eh(void *data, async_cookie_t cookie)
        sas_put_device(dev);
 }
 
-static bool sas_ata_dev_eh_valid(struct domain_device *dev)
-{
-       struct ata_port *ap;
-
-       if (!dev_is_sata(dev))
-               return false;
-       ap = dev->sata_dev.ap;
-       /* consume fully initialized ata ports */
-       smp_rmb();
-       return !!ap;
-}
-
 void sas_ata_strategy_handler(struct Scsi_Host *shost)
 {
        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
@@ -753,7 +740,7 @@ void sas_ata_strategy_handler(struct Scsi_Host *shost)
 
                spin_lock(&port->dev_list_lock);
                list_for_each_entry(dev, &port->dev_list, dev_list_node) {
-                       if (!sas_ata_dev_eh_valid(dev))
+                       if (!dev_is_sata(dev))
                                continue;
                        async_schedule_domain(async_sas_ata_eh, dev, &async);
                }

diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 13b5891..629a086 100644 (file)
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -72,6 +72,7 @@ static int sas_get_port_device(struct asd_sas_port *port)
        struct asd_sas_phy *phy;
        struct sas_rphy *rphy;
        struct domain_device *dev;
+       int rc = -ENODEV;
 
        dev = sas_alloc_device();
        if (!dev)
@@ -110,9 +111,16 @@ static int sas_get_port_device(struct asd_sas_port *port)
 
        sas_init_dev(dev);
 
+       dev->port = port;
        switch (dev->dev_type) {
-       case SAS_END_DEV:
        case SATA_DEV:
+               rc = sas_ata_init(dev);
+               if (rc) {
+                       rphy = NULL;
+                       break;
+               }
+               /* fall through */
+       case SAS_END_DEV:
                rphy = sas_end_device_alloc(port->port);
                break;
        case EDGE_DEV:
@@ -131,7 +139,7 @@ static int sas_get_port_device(struct asd_sas_port *port)
 
        if (!rphy) {
                sas_put_device(dev);
-               return -ENODEV;
+               return rc;
        }
 
        rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
@@ -139,7 +147,6 @@ static int sas_get_port_device(struct asd_sas_port *port)
        sas_fill_in_rphy(dev, rphy);
        sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
        port->port_dev = dev;
-       dev->port = port;
        dev->linkrate = port->linkrate;
        dev->min_linkrate = port->linkrate;
        dev->max_linkrate = port->linkrate;

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index c1f91b1..75247a1 100644 (file)
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -790,12 +790,14 @@ static struct domain_device *sas_ex_discover_end_dev(
                if (res)
                        goto out_free;
 
+               sas_init_dev(child);
+               res = sas_ata_init(child);
+               if (res)
+                       goto out_free;
                rphy = sas_end_device_alloc(phy->port);
-               if (unlikely(!rphy))
+               if (!rphy)
                        goto out_free;
 
-               sas_init_dev(child);
-
                child->rphy = rphy;
                get_device(&rphy->dev);
 

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 42378d6..e926df7 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -996,7 +996,8 @@ extern int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *dev,
 extern void ata_sas_port_destroy(struct ata_port *);
 extern struct ata_port *ata_sas_port_alloc(struct ata_host *,
                                           struct ata_port_info *, struct Scsi_Host *);
-extern int ata_sas_async_port_init(struct ata_port *);
+extern void ata_sas_async_probe(struct ata_port *ap);
+extern int ata_sas_sync_probe(struct ata_port *ap);
 extern int ata_sas_port_init(struct ata_port *);
 extern int ata_sas_port_start(struct ata_port *ap);
 extern void ata_sas_port_stop(struct ata_port *ap);

diff --git a/include/scsi/sas_ata.h b/include/scsi/sas_ata.h
index cdccd2e..77670e8 100644 (file)
--- a/include/scsi/sas_ata.h
+++ b/include/scsi/sas_ata.h
@@ -37,7 +37,7 @@ static inline int dev_is_sata(struct domain_device *dev)
 }
 
 int sas_get_ata_info(struct domain_device *dev, struct ex_phy *phy);
-int sas_ata_init_host_and_port(struct domain_device *found_dev);
+int sas_ata_init(struct domain_device *dev);
 void sas_ata_task_abort(struct sas_task *task);
 void sas_ata_strategy_handler(struct Scsi_Host *shost);
 void sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
@@ -52,7 +52,7 @@ static inline int dev_is_sata(struct domain_device *dev)
 {
        return 0;
 }
-static inline int sas_ata_init_host_and_port(struct domain_device *found_dev)
+static inline int sas_ata_init(struct domain_device *dev)
 {
        return 0;
 }