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authorDan Williams <dan.j.williams@intel.com>2011-11-17 17:59:51 -0800
committerJames Bottomley <JBottomley@Parallels.com>2012-02-19 13:52:34 -0600
commit87c8331fcf72e501c3a3c0cdc5c9391ec72f7cf2 (patch)
tree4ed0e98760c977010fe54778c1a25625840b4583 /drivers/scsi/scsi_transport_sas.c
parente139942d77a6e3ac83bc322e826668054a8601d6 (diff)
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[SCSI] libsas: prevent domain rediscovery competing with ata error handling
libata error handling provides for a timeout for link recovery. libsas must not rescan for previously known devices in this interval otherwise it may remove a device that is simply waiting for its link to recover. Let libata-eh make the determination of when the link is stable and prevent libsas (host workqueue) from taking action while this determination is pending. Using a mutex (ha->disco_mutex) to flush and disable revalidation while eh is running requires any discovery action that may block on eh be moved to its own context outside the lock. Probing ATA devices explicitly waits on ata-eh and the cache-flush-io issued during device removal may also pend awaiting eh completion. Essentially any rphy add/remove activity needs to run outside the lock. This adds two new cleanup states for sas_unregister_domain_devices() 'allocated-but-not-probed', and 'flagged-for-destruction'. In the 'allocated-but-not-probed' state dev->rphy points to a rphy that is known to have not been through a sas_rphy_add() event. At domain teardown check if this device is still pending probe and cleanup accordingly. Similarly if a device has already been queued for removal then sas_unregister_domain_devices has nothing to do. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/scsi_transport_sas.c')
-rw-r--r--drivers/scsi/scsi_transport_sas.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 9d9330ae4213..9421bae8af1a 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -1603,6 +1603,20 @@ sas_rphy_delete(struct sas_rphy *rphy)
EXPORT_SYMBOL(sas_rphy_delete);
/**
+ * sas_rphy_unlink - unlink SAS remote PHY
+ * @rphy: SAS remote phy to unlink from its parent port
+ *
+ * Removes port reference to an rphy
+ */
+void sas_rphy_unlink(struct sas_rphy *rphy)
+{
+ struct sas_port *parent = dev_to_sas_port(rphy->dev.parent);
+
+ parent->rphy = NULL;
+}
+EXPORT_SYMBOL(sas_rphy_unlink);
+
+/**
* sas_rphy_remove - remove SAS remote PHY
* @rphy: SAS remote phy to remove
*
@@ -1612,7 +1626,6 @@ void
sas_rphy_remove(struct sas_rphy *rphy)
{
struct device *dev = &rphy->dev;
- struct sas_port *parent = dev_to_sas_port(dev->parent);
switch (rphy->identify.device_type) {
case SAS_END_DEVICE:
@@ -1626,10 +1639,9 @@ sas_rphy_remove(struct sas_rphy *rphy)
break;
}
+ sas_rphy_unlink(rphy);
transport_remove_device(dev);
device_del(dev);
-
- parent->rphy = NULL;
}
EXPORT_SYMBOL(sas_rphy_remove);