| Message ID | 1495262360-40135-1-git-send-email-wangyijing@huawei.com |
|---|---|
| Headers | show |
| Series | Enhance libsas hotplug feature | expand |
Hi, There are some comments, inline. In general, if it works, it looks ok. Other reviews would be greatly appreciated - Hannes, Christoph, Johannes, Dan - please. > Libsas complete a hotplug event notified by LLDD in several works, > for example, if libsas receive a PHYE_LOSS_OF_SIGNAL, we process it > in following steps: > > notify_phy_event [interrupt context] > sas_queue_event [queue work on shost->work_q] > sas_phye_loss_of_signal [running in shost->work_q] > sas_deform_port [remove sas port] > sas_unregister_dev > sas_discover_event [queue destruct work on shost->work_q tail] > > In above case, complete whole hotplug in two works, remove sas port first, then > put the destruction of device in another work and queue it on in the tail of > workqueue, since sas port is the parent of the children rphy device, so if remove > sas port first, the children rphy device would also be deleted, when the destruction > work coming, it would find the target has been removed already, and report a > sysfs warning calltrace. > > queue tail queue head > DISCE_DESTRUCT----> PORTE_BYTES_DMAED event ----->PHYE_LOSS_OF_SIGNAL[running] > > There are other hotplug issues in current framework, in above case, if there is > hotadd sas event queued between hotremove works, the hotplug order would be broken > and unexpected issues would happen. > > In this patch, we try to solve these issues in following steps: > 1. create a new workqueue used to run sas event work, instead of scsi host workqueue, > because we may block sas event work, we cannot block the normal scsi works. What do we block the event work for? > 2. create a new workqueue used to run sas discovery events work, instead of scsi host > workqueue, because in some cases, eg. in revalidate domain event, we may unregister > a sas device and discover new one, we must sync the execution, wait the remove process > finish, then start a new discovery. So we must put the probe and destruct discovery > events in a new workqueue to avoid deadlock. > 3. introudce a asd_sas_port level wait-complete and a sas_discovery level wait-complete > we use former wait-complete to achieve a sas event atomic process and use latter to > make a sas discovery sync. > 4. remove disco_mutex in sas_revalidate_domain, since now sas_revalidate_domain sync > the destruct discovery event execution, it's no need to lock disco mutex there. > > Signed-off-by: Yijing Wang <wangyijing@huawei.com> > --- > drivers/scsi/libsas/sas_discover.c | 58 ++++++++++++++++++++++++++++---------- > drivers/scsi/libsas/sas_event.c | 2 +- > drivers/scsi/libsas/sas_expander.c | 9 +++++- > drivers/scsi/libsas/sas_init.c | 31 +++++++++++++++++++- > drivers/scsi/libsas/sas_internal.h | 50 ++++++++++++++++++++++++++++++++ > drivers/scsi/libsas/sas_port.c | 4 +++ > include/scsi/libsas.h | 11 +++++++- > 7 files changed, 146 insertions(+), 19 deletions(-) > > diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c > index 60de662..43e8a1e 100644 > --- a/drivers/scsi/libsas/sas_discover.c > +++ b/drivers/scsi/libsas/sas_discover.c > @@ -503,11 +503,10 @@ static void sas_revalidate_domain(struct work_struct *work) > struct domain_device *ddev = port->port_dev; > > /* prevent revalidation from finding sata links in recovery */ > - mutex_lock(&ha->disco_mutex); > if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) { > SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n", > port->id, task_pid_nr(current)); > - goto out; > + return; > } > > clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending); > @@ -521,20 +520,57 @@ static void sas_revalidate_domain(struct work_struct *work) > > SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n", > port->id, task_pid_nr(current), res); > - out: > - mutex_unlock(&ha->disco_mutex); > +} > + > +static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = { > + [DISCE_DISCOVER_DOMAIN] = sas_discover_domain, > + [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain, > + [DISCE_PROBE] = sas_probe_devices, > + [DISCE_SUSPEND] = sas_suspend_devices, > + [DISCE_RESUME] = sas_resume_devices, > + [DISCE_DESTRUCT] = sas_destruct_devices, > +}; > + > +/* a simple wrapper for sas discover event funtions */ > +static void sas_discover_common_fn(struct work_struct *work) > +{ > + struct sas_discovery_event *ev = to_sas_discovery_event(work); > + struct asd_sas_port *port = ev->port; > + > + sas_event_fns[ev->type](work); > + sas_unbusy_port(port); > } > > /* ---------- Events ---------- */ > > static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw) > { > + int ret; > + struct sas_discovery_event *ev = to_sas_discovery_event(&sw->work); > + struct asd_sas_port *port = ev->port; > + > /* chained work is not subject to SA_HA_DRAINING or > * SAS_HA_REGISTERED, because it is either submitted in the > * workqueue, or known to be submitted from a context that is > * not racing against draining > */ Is this comment still valid (even if you have not touched the drain logic work)? > - scsi_queue_work(ha->core.shost, &sw->work); > + sas_busy_port(port); > + > + /* > + * discovery event probe and destruct would be called in other > + * discovery event like discover domain and revalidate domain > + * events, in some cases, we need to sync execute probe and destruct > + * events, so run discover events except probe/destruct in a new > + * workqueue. > + */ > + if (ev->type == DISCE_PROBE || ev->type == DISCE_DESTRUCT) > + ret = scsi_queue_work(ha->core.shost, &sw->work); > + else > + ret = queue_work(ha->disc_q, &sw->work); > + > + if (ret != 1) > + /* queue a work fail, unbusy the ha before return */ > + sas_unbusy_port(port); Do we really need to check for this error case, since we have dynamic work structs (I think queue_work only fails if we try requeuing a work item)? > } > > static void sas_chain_event(int event, unsigned long *pending, > @@ -575,18 +611,10 @@ void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port) > { > int i; > > - static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = { > - [DISCE_DISCOVER_DOMAIN] = sas_discover_domain, > - [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain, > - [DISCE_PROBE] = sas_probe_devices, > - [DISCE_SUSPEND] = sas_suspend_devices, > - [DISCE_RESUME] = sas_resume_devices, > - [DISCE_DESTRUCT] = sas_destruct_devices, > - }; > - > disc->pending = 0; > for (i = 0; i < DISC_NUM_EVENTS; i++) { > - INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]); > + INIT_SAS_WORK(&disc->disc_work[i].work, sas_discover_common_fn); > disc->disc_work[i].port = port; > + disc->disc_work[i].type = i; > } > } > diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c > index 06c5c4b..c0fc07d 100644 > --- a/drivers/scsi/libsas/sas_event.c > +++ b/drivers/scsi/libsas/sas_event.c > @@ -41,7 +41,7 @@ void sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw) > if (list_empty(&sw->drain_node)) > list_add(&sw->drain_node, &ha->defer_q); > } else > - scsi_queue_work(ha->core.shost, &sw->work); > + queue_work(ha->event_q, &sw->work); > } > > static void sas_queue_event(int event, struct sas_work *work, > diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c > index 570b2cb..a8c8ae1 100644 > --- a/drivers/scsi/libsas/sas_expander.c > +++ b/drivers/scsi/libsas/sas_expander.c > @@ -822,7 +822,9 @@ static struct domain_device *sas_ex_discover_end_dev( > > list_add_tail(&child->disco_list_node, &parent->port->disco_list); > > + wait_discover_event_init(child->port); > res = sas_discover_sata(child); > + wait_for_discover_event_finish(child->port); > if (res) { > SAS_DPRINTK("sas_discover_sata() for device %16llx at " > "%016llx:0x%x returned 0x%x\n", > @@ -847,7 +849,9 @@ static struct domain_device *sas_ex_discover_end_dev( > > list_add_tail(&child->disco_list_node, &parent->port->disco_list); > > + wait_discover_event_init(child->port); > res = sas_discover_end_dev(child); In sas_discover_end_dev(), we may return before sending the queue event (if LLDD notify dev found returns error), we please take care of this. > + wait_for_discover_event_finish(child->port); > if (res) { > SAS_DPRINTK("sas_discover_end_dev() for device %16llx " > "at %016llx:0x%x returned 0x%x\n", > @@ -1890,8 +1894,11 @@ static void sas_unregister_devs_sas_addr(struct domain_device *parent, > if (child->dev_type == SAS_EDGE_EXPANDER_DEVICE || > child->dev_type == SAS_FANOUT_EXPANDER_DEVICE) > sas_unregister_ex_tree(parent->port, child); > - else > + else { > + wait_discover_event_init(parent->port); > sas_unregister_dev(parent->port, child); > + wait_for_discover_event_finish(parent->port); > + } > found = child; > break; > } > diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c > index 79f95d0..1c49483 100644 > --- a/drivers/scsi/libsas/sas_init.c > +++ b/drivers/scsi/libsas/sas_init.c > @@ -38,6 +38,8 @@ > > #include "../scsi_sas_internal.h" > > +static DEFINE_IDA(sas_ida); > + > static struct kmem_cache *sas_task_cache; > > struct sas_task *sas_alloc_task(gfp_t flags) > @@ -116,6 +118,7 @@ void sas_hae_reset(struct work_struct *work) > int sas_register_ha(struct sas_ha_struct *sas_ha) > { > int error = 0; > + char name[64]; > > mutex_init(&sas_ha->disco_mutex); > spin_lock_init(&sas_ha->phy_port_lock); > @@ -146,6 +149,30 @@ int sas_register_ha(struct sas_ha_struct *sas_ha) > goto Undo_ports; > } > > + sas_ha->id = ida_simple_get(&sas_ida, 0, 0, GFP_KERNEL); > + if(sas_ha->id < 0) > + goto Undo_ports; > + > + memset(name, 0, 64); Why memset and then sprintf? > + snprintf(name, 64, "sas-event-%d", sas_ha->id); Can you just use unique dev_name(sas_ha->dev) to help form this name, so that you don't have to introduce IDR? > + sas_ha->event_q = create_singlethread_workqueue(name); > + > + /* > + * sas-disc-xx workqueue run the discover work except > + * probe and destruct. > + */ > + snprintf(name, 64, "sas-disc-%d", sas_ha->id); > + sas_ha->disc_q = create_singlethread_workqueue(name); > + if(!sas_ha->event_q || !sas_ha->disc_q) { > + ida_simple_remove(&sas_ida, sas_ha->id); > + if (sas_ha->event_q) > + destroy_workqueue(sas_ha->event_q); > + if (sas_ha->disc_q) > + destroy_workqueue(sas_ha->disc_q); Can this error handling be a bit more concise? > + goto Undo_ports; > + } > + > + > INIT_LIST_HEAD(&sas_ha->eh_done_q); > INIT_LIST_HEAD(&sas_ha->eh_ata_q); > > @@ -181,6 +208,9 @@ int sas_unregister_ha(struct sas_ha_struct *sas_ha) > __sas_drain_work(sas_ha); > mutex_unlock(&sas_ha->drain_mutex); > > + destroy_workqueue(sas_ha->event_q); > + destroy_workqueue(sas_ha->disc_q); > + ida_simple_remove(&sas_ida, sas_ha->id); > return 0; > } > > @@ -568,7 +598,6 @@ void sas_domain_release_transport(struct scsi_transport_template *stt) > EXPORT_SYMBOL_GPL(sas_domain_release_transport); > > /* ---------- SAS Class register/unregister ---------- */ > - > static int __init sas_class_init(void) > { > sas_task_cache = KMEM_CACHE(sas_task, SLAB_HWCACHE_ALIGN); > diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h > index 33ce7e5..276df8e 100644 > --- a/drivers/scsi/libsas/sas_internal.h > +++ b/drivers/scsi/libsas/sas_internal.h > @@ -100,6 +100,56 @@ void sas_free_device(struct kref *kref); > extern const work_func_t sas_phy_event_fns[PHY_NUM_EVENTS]; > extern const work_func_t sas_port_event_fns[PORT_NUM_EVENTS]; > > +static inline void wait_discover_event_init(struct asd_sas_port *port) You need to change function names to have "sas" prefix. Actually these functions are all a bit messy. > +{ > + if (port) { This init and wait function are currently act ask bookend wrappers. I think it may be better to put them in the wrapped function (if possible), as: a. probably then we don't need port NULL check b. handles situations where event is possibly not queued, like the suspected sas_discover_end_dev() > + init_completion(&port->disc.completion); > + port->disc.wait = 1; > + } > +} > + > +static inline void wait_for_discover_event_finish( > + struct asd_sas_port *port) > +{ > + if (port && port->disc.wait == 1) Can you just use completion_done() instead of introducing another variable in discovery_event.wait? > + wait_for_completion(&port->disc.completion); > +} > + > +static inline void wait_sas_event_init(struct asd_sas_port *port) > +{ > + if (port) { > + init_completion(&port->completion); > + port->busy = 0; > + } > +} > + > +static inline void wait_for_sas_event_finish( > + struct asd_sas_port *port) > +{ > + if (port && port->busy) > + wait_for_completion(&port->completion); > +} > + > +static inline void sas_busy_port(struct asd_sas_port *port) > +{ > + if (port) > + port->busy++; Why not use kref? > +} > + > +static inline void sas_unbusy_port(struct asd_sas_port *port) > +{ > + if (port && (port->busy > 0)) { > + port->busy--; > + if (!port->busy) > + complete(&port->completion); > + } > + > + if (port && (port->disc.wait == 1)) { Why check port twice? > + complete(&port->disc.completion); > + port->disc.wait = 0; > + } > +} > + > #ifdef CONFIG_SCSI_SAS_HOST_SMP > extern int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req, > struct request *rsp); > diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c > index 9326628..8d8b38c 100644 > --- a/drivers/scsi/libsas/sas_port.c > +++ b/drivers/scsi/libsas/sas_port.c > @@ -191,7 +191,9 @@ static void sas_form_port(struct asd_sas_phy *phy) > if (si->dft->lldd_port_formed) > si->dft->lldd_port_formed(phy); > > + wait_sas_event_init(port); > sas_discover_event(phy->port, DISCE_DISCOVER_DOMAIN); > + wait_for_sas_event_finish(port); Is it neater to put these calls inside sas_discover_event()? > } > > /** > @@ -218,7 +220,9 @@ void sas_deform_port(struct asd_sas_phy *phy, int gone) > dev->pathways--; > > if (port->num_phys == 1) { > + wait_sas_event_init(port); > sas_unregister_domain_devices(port, gone); > + wait_for_sas_event_finish(port); > sas_port_delete(port->port); > port->port = NULL; > } else { > diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h > index c4444ad..4b931d4 100644 > --- a/include/scsi/libsas.h > +++ b/include/scsi/libsas.h > @@ -240,6 +240,9 @@ static inline void INIT_SAS_WORK(struct sas_work *sw, void (*fn)(struct work_str > struct sas_discovery_event { > struct sas_work work; > struct asd_sas_port *port; > + enum discover_event type; > + int wait; > + struct completion completion; > }; > > static inline struct sas_discovery_event *to_sas_discovery_event(struct work_struct *work) > @@ -256,6 +259,8 @@ struct sas_discovery { > u8 eeds_a[8]; > u8 eeds_b[8]; > int max_level; > + int wait; > + struct completion completion; Again, does completion_done() do the same job as wait element? > }; > > /* The port struct is Class:RW, driver:RO */ > @@ -276,7 +281,8 @@ struct asd_sas_port { > > /* public: */ > int id; > - > + int busy; > + struct completion completion; I think public means LLDD can access, which is not the case > enum sas_class class; > u8 sas_addr[SAS_ADDR_SIZE]; > u8 attached_sas_addr[SAS_ADDR_SIZE]; > @@ -387,6 +393,7 @@ struct sas_ha_struct { > int eh_active; > wait_queue_head_t eh_wait_q; > struct list_head eh_dev_q; > + int id; /* for create workqueue */ > > struct mutex disco_mutex; > > @@ -396,6 +403,8 @@ struct sas_ha_struct { > char *sas_ha_name; > struct device *dev; /* should be set */ > struct module *lldd_module; /* should be set */ > + struct workqueue_struct *event_q; > + struct workqueue_struct *disc_q; > > u8 *sas_addr; /* must be set */ > u8 hashed_sas_addr[HASHED_SAS_ADDR_SIZE]; >
Hi John, thanks for your review and comments! 在 2017/5/25 17:04, John Garry 写道: > Hi, > > There are some comments, inline. > > In general, if it works, it looks ok. > > Other reviews would be greatly appreciated - Hannes, Christoph, Johannes, Dan - please. > >> Libsas complete a hotplug event notified by LLDD in several works, >> for example, if libsas receive a PHYE_LOSS_OF_SIGNAL, we process it >> in following steps: >> >> notify_phy_event [interrupt context] >> sas_queue_event [queue work on shost->work_q] >> sas_phye_loss_of_signal [running in shost->work_q] >> sas_deform_port [remove sas port] >> sas_unregister_dev >> sas_discover_event [queue destruct work on shost->work_q tail] >> >> In above case, complete whole hotplug in two works, remove sas port first, then >> put the destruction of device in another work and queue it on in the tail of >> workqueue, since sas port is the parent of the children rphy device, so if remove >> sas port first, the children rphy device would also be deleted, when the destruction >> work coming, it would find the target has been removed already, and report a >> sysfs warning calltrace. >> >> queue tail queue head >> DISCE_DESTRUCT----> PORTE_BYTES_DMAED event ----->PHYE_LOSS_OF_SIGNAL[running] >> >> There are other hotplug issues in current framework, in above case, if there is >> hotadd sas event queued between hotremove works, the hotplug order would be broken >> and unexpected issues would happen. >> >> In this patch, we try to solve these issues in following steps: >> 1. create a new workqueue used to run sas event work, instead of scsi host workqueue, >> because we may block sas event work, we cannot block the normal scsi works. > > What do we block the event work for? When libsas receive a phy down event, sas_deform_port would be called, and now we block sas_deform_port and wait for destruction work finish, in sas_destruct_devices, we may wait ata error handler, it would take a long time, so if do all stuff in scsi host workq, libsas may block other scsi works too long. > >> 2. create a new workqueue used to run sas discovery events work, instead of scsi host >> workqueue, because in some cases, eg. in revalidate domain event, we may unregister >> a sas device and discover new one, we must sync the execution, wait the remove process >> finish, then start a new discovery. So we must put the probe and destruct discovery >> events in a new workqueue to avoid deadlock. >> 3. introudce a asd_sas_port level wait-complete and a sas_discovery level wait-complete >> we use former wait-complete to achieve a sas event atomic process and use latter to >> make a sas discovery sync. >> 4. remove disco_mutex in sas_revalidate_domain, since now sas_revalidate_domain sync >> the destruct discovery event execution, it's no need to lock disco mutex there. >> >> Signed-off-by: Yijing Wang <wangyijing@huawei.com> >> --- >> drivers/scsi/libsas/sas_discover.c | 58 ++++++++++++++++++++++++++++---------- >> drivers/scsi/libsas/sas_event.c | 2 +- >> drivers/scsi/libsas/sas_expander.c | 9 +++++- >> drivers/scsi/libsas/sas_init.c | 31 +++++++++++++++++++- >> drivers/scsi/libsas/sas_internal.h | 50 ++++++++++++++++++++++++++++++++ >> drivers/scsi/libsas/sas_port.c | 4 +++ >> include/scsi/libsas.h | 11 +++++++- >> 7 files changed, 146 insertions(+), 19 deletions(-) >> >> diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c >> index 60de662..43e8a1e 100644 >> --- a/drivers/scsi/libsas/sas_discover.c >> +++ b/drivers/scsi/libsas/sas_discover.c >> @@ -503,11 +503,10 @@ static void sas_revalidate_domain(struct work_struct *work) >> struct domain_device *ddev = port->port_dev; >> >> /* prevent revalidation from finding sata links in recovery */ >> - mutex_lock(&ha->disco_mutex); >> if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) { >> SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n", >> port->id, task_pid_nr(current)); >> - goto out; >> + return; >> } >> >> clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending); >> @@ -521,20 +520,57 @@ static void sas_revalidate_domain(struct work_struct *work) >> >> SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n", >> port->id, task_pid_nr(current), res); >> - out: >> - mutex_unlock(&ha->disco_mutex); >> +} >> + >> +static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = { >> + [DISCE_DISCOVER_DOMAIN] = sas_discover_domain, >> + [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain, >> + [DISCE_PROBE] = sas_probe_devices, >> + [DISCE_SUSPEND] = sas_suspend_devices, >> + [DISCE_RESUME] = sas_resume_devices, >> + [DISCE_DESTRUCT] = sas_destruct_devices, >> +}; >> + >> +/* a simple wrapper for sas discover event funtions */ >> +static void sas_discover_common_fn(struct work_struct *work) >> +{ >> + struct sas_discovery_event *ev = to_sas_discovery_event(work); >> + struct asd_sas_port *port = ev->port; >> + >> + sas_event_fns[ev->type](work); >> + sas_unbusy_port(port); >> } >> >> /* ---------- Events ---------- */ >> >> static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw) >> { >> + int ret; >> + struct sas_discovery_event *ev = to_sas_discovery_event(&sw->work); >> + struct asd_sas_port *port = ev->port; >> + >> /* chained work is not subject to SA_HA_DRAINING or >> * SAS_HA_REGISTERED, because it is either submitted in the >> * workqueue, or known to be submitted from a context that is >> * not racing against draining >> */ > > Is this comment still valid (even if you have not touched the drain logic work)? Yes, I think so. > >> - scsi_queue_work(ha->core.shost, &sw->work); >> + sas_busy_port(port); >> + >> + /* >> + * discovery event probe and destruct would be called in other >> + * discovery event like discover domain and revalidate domain >> + * events, in some cases, we need to sync execute probe and destruct >> + * events, so run discover events except probe/destruct in a new >> + * workqueue. >> + */ >> + if (ev->type == DISCE_PROBE || ev->type == DISCE_DESTRUCT) >> + ret = scsi_queue_work(ha->core.shost, &sw->work); >> + else >> + ret = queue_work(ha->disc_q, &sw->work); >> + >> + if (ret != 1) >> + /* queue a work fail, unbusy the ha before return */ >> + sas_unbusy_port(port); > > Do we really need to check for this error case, since we have dynamic work structs (I think queue_work only fails if we try requeuing a work item)? We only change sas event work to dynamic, for sas discovery event work, it's still static. > >> } >> >> static void sas_chain_event(int event, unsigned long *pending, >> @@ -575,18 +611,10 @@ void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port) >> { >> int i; >> >> - static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = { >> - [DISCE_DISCOVER_DOMAIN] = sas_discover_domain, >> - [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain, >> - [DISCE_PROBE] = sas_probe_devices, >> - [DISCE_SUSPEND] = sas_suspend_devices, >> - [DISCE_RESUME] = sas_resume_devices, >> - [DISCE_DESTRUCT] = sas_destruct_devices, >> - }; >> - >> disc->pending = 0; >> for (i = 0; i < DISC_NUM_EVENTS; i++) { >> - INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]); >> + INIT_SAS_WORK(&disc->disc_work[i].work, sas_discover_common_fn); >> disc->disc_work[i].port = port; >> + disc->disc_work[i].type = i; >> } >> } >> diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c >> index 06c5c4b..c0fc07d 100644 >> --- a/drivers/scsi/libsas/sas_event.c >> +++ b/drivers/scsi/libsas/sas_event.c >> @@ -41,7 +41,7 @@ void sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw) >> if (list_empty(&sw->drain_node)) >> list_add(&sw->drain_node, &ha->defer_q); >> } else >> - scsi_queue_work(ha->core.shost, &sw->work); >> + queue_work(ha->event_q, &sw->work); >> } >> >> static void sas_queue_event(int event, struct sas_work *work, >> diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c >> index 570b2cb..a8c8ae1 100644 >> --- a/drivers/scsi/libsas/sas_expander.c >> +++ b/drivers/scsi/libsas/sas_expander.c >> @@ -822,7 +822,9 @@ static struct domain_device *sas_ex_discover_end_dev( >> >> list_add_tail(&child->disco_list_node, &parent->port->disco_list); >> >> + wait_discover_event_init(child->port); >> res = sas_discover_sata(child); >> + wait_for_discover_event_finish(child->port); >> if (res) { >> SAS_DPRINTK("sas_discover_sata() for device %16llx at " >> "%016llx:0x%x returned 0x%x\n", >> @@ -847,7 +849,9 @@ static struct domain_device *sas_ex_discover_end_dev( >> >> list_add_tail(&child->disco_list_node, &parent->port->disco_list); >> >> + wait_discover_event_init(child->port); >> res = sas_discover_end_dev(child); > > In sas_discover_end_dev(), we may return before sending the queue event (if LLDD notify dev found returns error), we please take care of this. Good catch, I will fix this case, thanks! > >> + wait_for_discover_event_finish(child->port); >> if (res) { >> SAS_DPRINTK("sas_discover_end_dev() for device %16llx " >> "at %016llx:0x%x returned 0x%x\n", >> @@ -1890,8 +1894,11 @@ static void sas_unregister_devs_sas_addr(struct domain_device *parent, >> if (child->dev_type == SAS_EDGE_EXPANDER_DEVICE || >> child->dev_type == SAS_FANOUT_EXPANDER_DEVICE) >> sas_unregister_ex_tree(parent->port, child); >> - else >> + else { >> + wait_discover_event_init(parent->port); >> sas_unregister_dev(parent->port, child); >> + wait_for_discover_event_finish(parent->port); >> + } >> found = child; >> break; >> } >> diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c >> index 79f95d0..1c49483 100644 >> --- a/drivers/scsi/libsas/sas_init.c >> +++ b/drivers/scsi/libsas/sas_init.c >> @@ -38,6 +38,8 @@ >> >> #include "../scsi_sas_internal.h" >> >> +static DEFINE_IDA(sas_ida); >> + >> static struct kmem_cache *sas_task_cache; >> >> struct sas_task *sas_alloc_task(gfp_t flags) >> @@ -116,6 +118,7 @@ void sas_hae_reset(struct work_struct *work) >> int sas_register_ha(struct sas_ha_struct *sas_ha) >> { >> int error = 0; >> + char name[64]; >> >> mutex_init(&sas_ha->disco_mutex); >> spin_lock_init(&sas_ha->phy_port_lock); >> @@ -146,6 +149,30 @@ int sas_register_ha(struct sas_ha_struct *sas_ha) >> goto Undo_ports; >> } >> >> + sas_ha->id = ida_simple_get(&sas_ida, 0, 0, GFP_KERNEL); >> + if(sas_ha->id < 0) >> + goto Undo_ports; >> + >> + memset(name, 0, 64); > > Why memset and then sprintf? > >> + snprintf(name, 64, "sas-event-%d", sas_ha->id); > > Can you just use unique dev_name(sas_ha->dev) to help form this name, so that you don't have to introduce IDR? I check the sas_ha->dev, and found it's point to platform device, so it should be safe to use dev_name(sas_ha->dev), thanks! > >> + sas_ha->event_q = create_singlethread_workqueue(name); >> + >> + /* >> + * sas-disc-xx workqueue run the discover work except >> + * probe and destruct. >> + */ >> + snprintf(name, 64, "sas-disc-%d", sas_ha->id); >> + sas_ha->disc_q = create_singlethread_workqueue(name); >> + if(!sas_ha->event_q || !sas_ha->disc_q) { >> + ida_simple_remove(&sas_ida, sas_ha->id); >> + if (sas_ha->event_q) >> + destroy_workqueue(sas_ha->event_q); >> + if (sas_ha->disc_q) >> + destroy_workqueue(sas_ha->disc_q); > > Can this error handling be a bit more concise? OK, will refresh. > >> + goto Undo_ports; >> + } >> + >> + >> INIT_LIST_HEAD(&sas_ha->eh_done_q); >> INIT_LIST_HEAD(&sas_ha->eh_ata_q); >> >> @@ -181,6 +208,9 @@ int sas_unregister_ha(struct sas_ha_struct *sas_ha) >> __sas_drain_work(sas_ha); >> mutex_unlock(&sas_ha->drain_mutex); >> >> + destroy_workqueue(sas_ha->event_q); >> + destroy_workqueue(sas_ha->disc_q); >> + ida_simple_remove(&sas_ida, sas_ha->id); >> return 0; >> } >> >> @@ -568,7 +598,6 @@ void sas_domain_release_transport(struct scsi_transport_template *stt) >> EXPORT_SYMBOL_GPL(sas_domain_release_transport); >> >> /* ---------- SAS Class register/unregister ---------- */ >> - >> static int __init sas_class_init(void) >> { >> sas_task_cache = KMEM_CACHE(sas_task, SLAB_HWCACHE_ALIGN); >> diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h >> index 33ce7e5..276df8e 100644 >> --- a/drivers/scsi/libsas/sas_internal.h >> +++ b/drivers/scsi/libsas/sas_internal.h >> @@ -100,6 +100,56 @@ void sas_free_device(struct kref *kref); >> extern const work_func_t sas_phy_event_fns[PHY_NUM_EVENTS]; >> extern const work_func_t sas_port_event_fns[PORT_NUM_EVENTS]; >> >> +static inline void wait_discover_event_init(struct asd_sas_port *port) > > You need to change function names to have "sas" prefix. Actually these functions are all a bit messy. OK. > >> +{ >> + if (port) { > > This init and wait function are currently act ask bookend wrappers. I think it may be better to put them in the wrapped function (if possible), as: > a. probably then we don't need port NULL check > b. handles situations where event is possibly not queued, like the suspected sas_discover_end_dev() > >> + init_completion(&port->disc.completion); >> + port->disc.wait = 1; >> + } >> +} >> + >> +static inline void wait_for_discover_event_finish( >> + struct asd_sas_port *port) >> +{ >> + if (port && port->disc.wait == 1) > > Can you just use completion_done() instead of introducing another variable in discovery_event.wait? What I am worried about completion_done() may be called before we call wait_for_compltion(), in this case, the process will hang. > >> + wait_for_completion(&port->disc.completion); >> +} >> + >> +static inline void wait_sas_event_init(struct asd_sas_port *port) >> +{ >> + if (port) { >> + init_completion(&port->completion); >> + port->busy = 0; >> + } >> +} >> + >> +static inline void wait_for_sas_event_finish( >> + struct asd_sas_port *port) >> +{ >> + if (port && port->busy) >> + wait_for_completion(&port->completion); >> +} >> + >> +static inline void sas_busy_port(struct asd_sas_port *port) >> +{ >> + if (port) >> + port->busy++; > > Why not use kref? Good idea, will replace. > >> +} >> + >> +static inline void sas_unbusy_port(struct asd_sas_port *port) >> +{ >> + if (port && (port->busy > 0)) { >> + port->busy--; >> + if (!port->busy) >> + complete(&port->completion); >> + } >> + >> + if (port && (port->disc.wait == 1)) { > > Why check port twice? Will remove the second check, thanks! > >> + complete(&port->disc.completion); >> + port->disc.wait = 0; >> + } >> +} >> + >> #ifdef CONFIG_SCSI_SAS_HOST_SMP >> extern int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req, >> struct request *rsp); >> diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c >> index 9326628..8d8b38c 100644 >> --- a/drivers/scsi/libsas/sas_port.c >> +++ b/drivers/scsi/libsas/sas_port.c >> @@ -191,7 +191,9 @@ static void sas_form_port(struct asd_sas_phy *phy) >> if (si->dft->lldd_port_formed) >> si->dft->lldd_port_formed(phy); >> >> + wait_sas_event_init(port); >> sas_discover_event(phy->port, DISCE_DISCOVER_DOMAIN); >> + wait_for_sas_event_finish(port); > > Is it neater to put these calls inside sas_discover_event()? Now we have two wait-complete, first for sas event, like in sas_form_port/sas_deform_port, second, for sas_discover event, like in sas_revalidate_domain, also, sas_discover_event() may be called recursive, there is some difficult to put these calls inside it. > >> } >> >> /** >> @@ -218,7 +220,9 @@ void sas_deform_port(struct asd_sas_phy *phy, int gone) >> dev->pathways--; >> >> if (port->num_phys == 1) { >> + wait_sas_event_init(port); >> sas_unregister_domain_devices(port, gone); >> + wait_for_sas_event_finish(port); >> sas_port_delete(port->port); >> port->port = NULL; >> } else { >> diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h >> index c4444ad..4b931d4 100644 >> --- a/include/scsi/libsas.h >> +++ b/include/scsi/libsas.h >> @@ -240,6 +240,9 @@ static inline void INIT_SAS_WORK(struct sas_work *sw, void (*fn)(struct work_str >> struct sas_discovery_event { >> struct sas_work work; >> struct asd_sas_port *port; >> + enum discover_event type; >> + int wait; >> + struct completion completion; >> }; >> >> static inline struct sas_discovery_event *to_sas_discovery_event(struct work_struct *work) >> @@ -256,6 +259,8 @@ struct sas_discovery { >> u8 eeds_a[8]; >> u8 eeds_b[8]; >> int max_level; >> + int wait; >> + struct completion completion; > > Again, does completion_done() do the same job as wait element? same as above. > >> }; >> >> /* The port struct is Class:RW, driver:RO */ >> @@ -276,7 +281,8 @@ struct asd_sas_port { >> >> /* public: */ >> int id; >> - >> + int busy; >> + struct completion completion; > > I think public means LLDD can access, which is not the case OK. will move them up. > >> enum sas_class class; >> u8 sas_addr[SAS_ADDR_SIZE]; >> u8 attached_sas_addr[SAS_ADDR_SIZE]; >> @@ -387,6 +393,7 @@ struct sas_ha_struct { >> int eh_active; >> wait_queue_head_t eh_wait_q; >> struct list_head eh_dev_q; >> + int id; /* for create workqueue */ >> >> struct mutex disco_mutex; >> >> @@ -396,6 +403,8 @@ struct sas_ha_struct { >> char *sas_ha_name; >> struct device *dev; /* should be set */ >> struct module *lldd_module; /* should be set */ >> + struct workqueue_struct *event_q; >> + struct workqueue_struct *disc_q; >> >> u8 *sas_addr; /* must be set */ >> u8 hashed_sas_addr[HASHED_SAS_ADDR_SIZE]; >> > > > . >