Commit e4a9c373 authored by Dan Williams's avatar Dan Williams Committed by James Bottomley

[SCSI] libata, libsas: introduce sched_eh and end_eh port ops

When managing shost->host_eh_scheduled libata assumes that there is a
1:1 shost-to-ata_port relationship.  libsas creates a 1:N relationship
so it needs to manage host_eh_scheduled cumulatively at the host level.
The sched_eh and end_eh port port ops allow libsas to track when domain
devices enter/leave the "eh-pending" state under ha->lock (previously
named ha->state_lock, but it is no longer just a lock for ha->state
changes).

Since host_eh_scheduled indicates eh without backing commands pinning
the device it can be deallocated at any time.  Move the taking of the
domain_device reference under the port_lock to guarantee that the
ata_port stays around for the duration of eh.
Reviewed-by: 's avatarJacek Danecki <jacek.danecki@intel.com>
Acked-by: 's avatarJeff Garzik <jgarzik@redhat.com>
Signed-off-by: 's avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: 's avatarJames Bottomley <JBottomley@Parallels.com>
parent 3b661a92
......@@ -80,6 +80,8 @@ const struct ata_port_operations ata_base_port_ops = {
.prereset = ata_std_prereset,
.postreset = ata_std_postreset,
.error_handler = ata_std_error_handler,
.sched_eh = ata_std_sched_eh,
.end_eh = ata_std_end_eh,
};
const struct ata_port_operations sata_port_ops = {
......@@ -6642,6 +6644,8 @@ struct ata_port_operations ata_dummy_port_ops = {
.qc_prep = ata_noop_qc_prep,
.qc_issue = ata_dummy_qc_issue,
.error_handler = ata_dummy_error_handler,
.sched_eh = ata_std_sched_eh,
.end_eh = ata_std_end_eh,
};
const struct ata_port_info ata_dummy_port_info = {
......
......@@ -793,12 +793,12 @@ void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
ata_for_each_link(link, ap, HOST_FIRST)
memset(&link->eh_info, 0, sizeof(link->eh_info));
/* Clear host_eh_scheduled while holding ap->lock such
* that if exception occurs after this point but
* before EH completion, SCSI midlayer will
/* end eh (clear host_eh_scheduled) while holding
* ap->lock such that if exception occurs after this
* point but before EH completion, SCSI midlayer will
* re-initiate EH.
*/
host->host_eh_scheduled = 0;
ap->ops->end_eh(ap);
spin_unlock_irqrestore(ap->lock, flags);
ata_eh_release(ap);
......@@ -986,16 +986,13 @@ void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
}
/**
* ata_port_schedule_eh - schedule error handling without a qc
* @ap: ATA port to schedule EH for
*
* Schedule error handling for @ap. EH will kick in as soon as
* all commands are drained.
* ata_std_sched_eh - non-libsas ata_ports issue eh with this common routine
* @ap: ATA port to schedule EH for
*
* LOCKING:
* LOCKING: inherited from ata_port_schedule_eh
* spin_lock_irqsave(host lock)
*/
void ata_port_schedule_eh(struct ata_port *ap)
void ata_std_sched_eh(struct ata_port *ap)
{
WARN_ON(!ap->ops->error_handler);
......@@ -1007,6 +1004,44 @@ void ata_port_schedule_eh(struct ata_port *ap)
DPRINTK("port EH scheduled\n");
}
EXPORT_SYMBOL_GPL(ata_std_sched_eh);
/**
* ata_std_end_eh - non-libsas ata_ports complete eh with this common routine
* @ap: ATA port to end EH for
*
* In the libata object model there is a 1:1 mapping of ata_port to
* shost, so host fields can be directly manipulated under ap->lock, in
* the libsas case we need to hold a lock at the ha->level to coordinate
* these events.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*/
void ata_std_end_eh(struct ata_port *ap)
{
struct Scsi_Host *host = ap->scsi_host;
host->host_eh_scheduled = 0;
}
EXPORT_SYMBOL(ata_std_end_eh);
/**
* ata_port_schedule_eh - schedule error handling without a qc
* @ap: ATA port to schedule EH for
*
* Schedule error handling for @ap. EH will kick in as soon as
* all commands are drained.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*/
void ata_port_schedule_eh(struct ata_port *ap)
{
/* see: ata_std_sched_eh, unless you know better */
ap->ops->sched_eh(ap);
}
static int ata_do_link_abort(struct ata_port *ap, struct ata_link *link)
{
......
......@@ -523,6 +523,31 @@ static void sas_ata_set_dmamode(struct ata_port *ap, struct ata_device *ata_dev)
i->dft->lldd_ata_set_dmamode(dev);
}
static void sas_ata_sched_eh(struct ata_port *ap)
{
struct domain_device *dev = ap->private_data;
struct sas_ha_struct *ha = dev->port->ha;
unsigned long flags;
spin_lock_irqsave(&ha->lock, flags);
if (!test_and_set_bit(SAS_DEV_EH_PENDING, &dev->state))
ha->eh_active++;
ata_std_sched_eh(ap);
spin_unlock_irqrestore(&ha->lock, flags);
}
void sas_ata_end_eh(struct ata_port *ap)
{
struct domain_device *dev = ap->private_data;
struct sas_ha_struct *ha = dev->port->ha;
unsigned long flags;
spin_lock_irqsave(&ha->lock, flags);
if (test_and_clear_bit(SAS_DEV_EH_PENDING, &dev->state))
ha->eh_active--;
spin_unlock_irqrestore(&ha->lock, flags);
}
static struct ata_port_operations sas_sata_ops = {
.prereset = ata_std_prereset,
.hardreset = sas_ata_hard_reset,
......@@ -536,6 +561,8 @@ static struct ata_port_operations sas_sata_ops = {
.port_start = ata_sas_port_start,
.port_stop = ata_sas_port_stop,
.set_dmamode = sas_ata_set_dmamode,
.sched_eh = sas_ata_sched_eh,
.end_eh = sas_ata_end_eh,
};
static struct ata_port_info sata_port_info = {
......@@ -708,10 +735,6 @@ static void async_sas_ata_eh(void *data, async_cookie_t cookie)
struct ata_port *ap = dev->sata_dev.ap;
struct sas_ha_struct *ha = dev->port->ha;
/* hold a reference over eh since we may be racing with final
* remove once all commands are completed
*/
kref_get(&dev->kref);
sas_ata_printk(KERN_DEBUG, dev, "dev error handler\n");
ata_scsi_port_error_handler(ha->core.shost, ap);
sas_put_device(dev);
......@@ -742,6 +765,13 @@ void sas_ata_strategy_handler(struct Scsi_Host *shost)
list_for_each_entry(dev, &port->dev_list, dev_list_node) {
if (!dev_is_sata(dev))
continue;
/* hold a reference over eh since we may be
* racing with final remove once all commands
* are completed
*/
kref_get(&dev->kref);
async_schedule_domain(async_sas_ata_eh, dev, &async);
}
spin_unlock(&port->dev_list_lock);
......
......@@ -294,6 +294,8 @@ static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_d
spin_lock_irq(&port->dev_list_lock);
list_del_init(&dev->dev_list_node);
if (dev_is_sata(dev))
sas_ata_end_eh(dev->sata_dev.ap);
spin_unlock_irq(&port->dev_list_lock);
sas_put_device(dev);
......@@ -488,9 +490,9 @@ static void sas_chain_event(int event, unsigned long *pending,
if (!test_and_set_bit(event, pending)) {
unsigned long flags;
spin_lock_irqsave(&ha->state_lock, flags);
spin_lock_irqsave(&ha->lock, flags);
sas_chain_work(ha, sw);
spin_unlock_irqrestore(&ha->state_lock, flags);
spin_unlock_irqrestore(&ha->lock, flags);
}
}
......
......@@ -47,9 +47,9 @@ static void sas_queue_event(int event, unsigned long *pending,
if (!test_and_set_bit(event, pending)) {
unsigned long flags;
spin_lock_irqsave(&ha->state_lock, flags);
spin_lock_irqsave(&ha->lock, flags);
sas_queue_work(ha, work);
spin_unlock_irqrestore(&ha->state_lock, flags);
spin_unlock_irqrestore(&ha->lock, flags);
}
}
......@@ -61,18 +61,18 @@ void __sas_drain_work(struct sas_ha_struct *ha)
set_bit(SAS_HA_DRAINING, &ha->state);
/* flush submitters */
spin_lock_irq(&ha->state_lock);
spin_unlock_irq(&ha->state_lock);
spin_lock_irq(&ha->lock);
spin_unlock_irq(&ha->lock);
drain_workqueue(wq);
spin_lock_irq(&ha->state_lock);
spin_lock_irq(&ha->lock);
clear_bit(SAS_HA_DRAINING, &ha->state);
list_for_each_entry_safe(sw, _sw, &ha->defer_q, drain_node) {
list_del_init(&sw->drain_node);
sas_queue_work(ha, sw);
}
spin_unlock_irq(&ha->state_lock);
spin_unlock_irq(&ha->lock);
}
int sas_drain_work(struct sas_ha_struct *ha)
......
......@@ -114,7 +114,7 @@ int sas_register_ha(struct sas_ha_struct *sas_ha)
sas_ha->lldd_queue_size = 128; /* Sanity */
set_bit(SAS_HA_REGISTERED, &sas_ha->state);
spin_lock_init(&sas_ha->state_lock);
spin_lock_init(&sas_ha->lock);
mutex_init(&sas_ha->drain_mutex);
INIT_LIST_HEAD(&sas_ha->defer_q);
......@@ -163,9 +163,9 @@ int sas_unregister_ha(struct sas_ha_struct *sas_ha)
* events to be queued, and flush any in-progress drainers
*/
mutex_lock(&sas_ha->drain_mutex);
spin_lock_irq(&sas_ha->state_lock);
spin_lock_irq(&sas_ha->lock);
clear_bit(SAS_HA_REGISTERED, &sas_ha->state);
spin_unlock_irq(&sas_ha->state_lock);
spin_unlock_irq(&sas_ha->lock);
__sas_drain_work(sas_ha);
mutex_unlock(&sas_ha->drain_mutex);
......@@ -411,9 +411,9 @@ static int queue_phy_reset(struct sas_phy *phy, int hard_reset)
d->reset_result = 0;
d->hard_reset = hard_reset;
spin_lock_irq(&ha->state_lock);
spin_lock_irq(&ha->lock);
sas_queue_work(ha, &d->reset_work);
spin_unlock_irq(&ha->state_lock);
spin_unlock_irq(&ha->lock);
rc = sas_drain_work(ha);
if (rc == 0)
......@@ -438,9 +438,9 @@ static int queue_phy_enable(struct sas_phy *phy, int enable)
d->enable_result = 0;
d->enable = enable;
spin_lock_irq(&ha->state_lock);
spin_lock_irq(&ha->lock);
sas_queue_work(ha, &d->enable_work);
spin_unlock_irq(&ha->state_lock);
spin_unlock_irq(&ha->lock);
rc = sas_drain_work(ha);
if (rc == 0)
......
......@@ -667,16 +667,20 @@ static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *
goto out;
}
void sas_scsi_recover_host(struct Scsi_Host *shost)
{
struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
unsigned long flags;
LIST_HEAD(eh_work_q);
int tries = 0;
bool retry;
spin_lock_irqsave(shost->host_lock, flags);
retry:
tries++;
retry = true;
spin_lock_irq(shost->host_lock);
list_splice_init(&shost->eh_cmd_q, &eh_work_q);
shost->host_eh_scheduled = 0;
spin_unlock_irqrestore(shost->host_lock, flags);
spin_unlock_irq(shost->host_lock);
SAS_DPRINTK("Enter %s busy: %d failed: %d\n",
__func__, shost->host_busy, shost->host_failed);
......@@ -710,8 +714,19 @@ out:
scsi_eh_flush_done_q(&ha->eh_done_q);
SAS_DPRINTK("--- Exit %s: busy: %d failed: %d\n",
__func__, shost->host_busy, shost->host_failed);
/* check if any new eh work was scheduled during the last run */
spin_lock_irq(&ha->lock);
if (ha->eh_active == 0) {
shost->host_eh_scheduled = 0;
retry = false;
}
spin_unlock_irq(&ha->lock);
if (retry)
goto retry;
SAS_DPRINTK("--- Exit %s: busy: %d failed: %d tries: %d\n",
__func__, shost->host_busy, shost->host_failed, tries);
}
enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
......
......@@ -846,6 +846,8 @@ struct ata_port_operations {
void (*error_handler)(struct ata_port *ap);
void (*lost_interrupt)(struct ata_port *ap);
void (*post_internal_cmd)(struct ata_queued_cmd *qc);
void (*sched_eh)(struct ata_port *ap);
void (*end_eh)(struct ata_port *ap);
/*
* Optional features
......@@ -1167,6 +1169,8 @@ extern void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
ata_postreset_fn_t postreset);
extern void ata_std_error_handler(struct ata_port *ap);
extern void ata_std_sched_eh(struct ata_port *ap);
extern void ata_std_end_eh(struct ata_port *ap);
extern int ata_link_nr_enabled(struct ata_link *link);
/*
......
......@@ -179,6 +179,7 @@ struct sata_device {
enum {
SAS_DEV_GONE,
SAS_DEV_DESTROY,
SAS_DEV_EH_PENDING,
};
struct domain_device {
......@@ -386,7 +387,8 @@ struct sas_ha_struct {
struct list_head defer_q; /* work queued while draining */
struct mutex drain_mutex;
unsigned long state;
spinlock_t state_lock;
spinlock_t lock;
int eh_active;
struct mutex disco_mutex;
......
......@@ -45,6 +45,7 @@ void sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
void sas_ata_schedule_reset(struct domain_device *dev);
void sas_ata_wait_eh(struct domain_device *dev);
void sas_probe_sata(struct asd_sas_port *port);
void sas_ata_end_eh(struct ata_port *ap);
#else
......@@ -85,6 +86,10 @@ static inline int sas_get_ata_info(struct domain_device *dev, struct ex_phy *phy
{
return 0;
}
static inline void sas_ata_end_eh(struct ata_port *ap)
{
}
#endif
#endif /* _SAS_ATA_H_ */
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