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-rw-r--r--drivers/xen/Makefile2
-rw-r--r--drivers/xen/events/events_base.c182
-rw-r--r--drivers/xen/evtchn.c34
-rw-r--r--drivers/xen/manage.c1
-rw-r--r--drivers/xen/unpopulated-alloc.c14
-rw-r--r--drivers/xen/xen-pciback/xenbus.c2
-rw-r--r--drivers/xen/xenbus/xenbus.h2
-rw-r--r--drivers/xen/xenbus/xenbus_client.c8
-rw-r--r--drivers/xen/xenbus/xenbus_probe.c1
-rw-r--r--drivers/xen/xenbus/xenbus_probe_backend.c7
-rw-r--r--drivers/xen/xenbus/xenbus_xs.c34
11 files changed, 166 insertions, 121 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index babdca808861..c3621b9f4012 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -21,7 +21,7 @@ obj-$(CONFIG_XEN_GNTDEV) += xen-gntdev.o
obj-$(CONFIG_XEN_GRANT_DEV_ALLOC) += xen-gntalloc.o
obj-$(CONFIG_XENFS) += xenfs/
obj-$(CONFIG_XEN_SYS_HYPERVISOR) += sys-hypervisor.o
-obj-$(CONFIG_XEN_PVHVM) += platform-pci.o
+obj-$(CONFIG_XEN_PVHVM_GUEST) += platform-pci.o
obj-$(CONFIG_SWIOTLB_XEN) += swiotlb-xen.o
obj-$(CONFIG_XEN_MCE_LOG) += mcelog.o
obj-$(CONFIG_XEN_PCIDEV_BACKEND) += xen-pciback/
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 6038c4c35db5..a8030332a191 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -95,7 +95,8 @@ struct irq_info {
struct list_head list;
struct list_head eoi_list;
short refcnt;
- short spurious_cnt;
+ u8 spurious_cnt;
+ u8 is_accounted;
enum xen_irq_type type; /* type */
unsigned irq;
evtchn_port_t evtchn; /* event channel */
@@ -161,6 +162,9 @@ static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
/* IRQ <-> IPI mapping */
static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
+/* Event channel distribution data */
+static atomic_t channels_on_cpu[NR_CPUS];
+
static int **evtchn_to_irq;
#ifdef CONFIG_X86
static unsigned long *pirq_eoi_map;
@@ -257,6 +261,32 @@ static void set_info_for_irq(unsigned int irq, struct irq_info *info)
irq_set_chip_data(irq, info);
}
+/* Per CPU channel accounting */
+static void channels_on_cpu_dec(struct irq_info *info)
+{
+ if (!info->is_accounted)
+ return;
+
+ info->is_accounted = 0;
+
+ if (WARN_ON_ONCE(info->cpu >= nr_cpu_ids))
+ return;
+
+ WARN_ON_ONCE(!atomic_add_unless(&channels_on_cpu[info->cpu], -1 , 0));
+}
+
+static void channels_on_cpu_inc(struct irq_info *info)
+{
+ if (WARN_ON_ONCE(info->cpu >= nr_cpu_ids))
+ return;
+
+ if (WARN_ON_ONCE(!atomic_add_unless(&channels_on_cpu[info->cpu], 1,
+ INT_MAX)))
+ return;
+
+ info->is_accounted = 1;
+}
+
/* Constructors for packed IRQ information. */
static int xen_irq_info_common_setup(struct irq_info *info,
unsigned irq,
@@ -339,6 +369,7 @@ static void xen_irq_info_cleanup(struct irq_info *info)
{
set_evtchn_to_irq(info->evtchn, -1);
info->evtchn = 0;
+ channels_on_cpu_dec(info);
}
/*
@@ -433,18 +464,25 @@ static bool pirq_needs_eoi_flag(unsigned irq)
return info->u.pirq.flags & PIRQ_NEEDS_EOI;
}
-static void bind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int cpu)
+static void bind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int cpu,
+ bool force_affinity)
{
int irq = get_evtchn_to_irq(evtchn);
struct irq_info *info = info_for_irq(irq);
BUG_ON(irq == -1);
-#ifdef CONFIG_SMP
- cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(cpu));
-#endif
+
+ if (IS_ENABLED(CONFIG_SMP) && force_affinity) {
+ cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(cpu));
+ cpumask_copy(irq_get_effective_affinity_mask(irq),
+ cpumask_of(cpu));
+ }
+
xen_evtchn_port_bind_to_cpu(evtchn, cpu, info->cpu);
+ channels_on_cpu_dec(info);
info->cpu = cpu;
+ channels_on_cpu_inc(info);
}
/**
@@ -523,8 +561,10 @@ static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious)
return;
if (spurious) {
- if ((1 << info->spurious_cnt) < (HZ << 2))
- info->spurious_cnt++;
+ if ((1 << info->spurious_cnt) < (HZ << 2)) {
+ if (info->spurious_cnt != 0xFF)
+ info->spurious_cnt++;
+ }
if (info->spurious_cnt > 1) {
delay = 1 << (info->spurious_cnt - 2);
if (delay > HZ)
@@ -615,11 +655,6 @@ static void xen_irq_init(unsigned irq)
{
struct irq_info *info;
-#ifdef CONFIG_SMP
- /* By default all event channels notify CPU#0. */
- cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(0));
-#endif
-
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (info == NULL)
panic("Unable to allocate metadata for IRQ%d\n", irq);
@@ -628,6 +663,11 @@ static void xen_irq_init(unsigned irq)
info->refcnt = -1;
set_info_for_irq(irq, info);
+ /*
+ * Interrupt affinity setting can be immediate. No point
+ * in delaying it until an interrupt is handled.
+ */
+ irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
INIT_LIST_HEAD(&info->eoi_list);
list_add_tail(&info->list, &xen_irq_list_head);
@@ -739,18 +779,7 @@ static void eoi_pirq(struct irq_data *data)
if (!VALID_EVTCHN(evtchn))
return;
- if (unlikely(irqd_is_setaffinity_pending(data)) &&
- likely(!irqd_irq_disabled(data))) {
- int masked = test_and_set_mask(evtchn);
-
- clear_evtchn(evtchn);
-
- irq_move_masked_irq(data);
-
- if (!masked)
- unmask_evtchn(evtchn);
- } else
- clear_evtchn(evtchn);
+ clear_evtchn(evtchn);
if (pirq_needs_eoi(data->irq)) {
rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
@@ -794,7 +823,7 @@ static unsigned int __startup_pirq(unsigned int irq)
goto err;
info->evtchn = evtchn;
- bind_evtchn_to_cpu(evtchn, 0);
+ bind_evtchn_to_cpu(evtchn, 0, false);
rc = xen_evtchn_port_setup(evtchn);
if (rc)
@@ -1113,8 +1142,14 @@ static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip)
irq = ret;
goto out;
}
- /* New interdomain events are bound to VCPU 0. */
- bind_evtchn_to_cpu(evtchn, 0);
+ /*
+ * New interdomain events are initially bound to vCPU0 This
+ * is required to setup the event channel in the first
+ * place and also important for UP guests because the
+ * affinity setting is not invoked on them so nothing would
+ * bind the channel.
+ */
+ bind_evtchn_to_cpu(evtchn, 0, false);
} else {
struct irq_info *info = info_for_irq(irq);
WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
@@ -1132,12 +1167,6 @@ int bind_evtchn_to_irq(evtchn_port_t evtchn)
}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
-int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn)
-{
- return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip);
-}
-EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi);
-
static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
{
struct evtchn_bind_ipi bind_ipi;
@@ -1168,7 +1197,11 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
irq = ret;
goto out;
}
- bind_evtchn_to_cpu(evtchn, cpu);
+ /*
+ * Force the affinity mask to the target CPU so proc shows
+ * the correct target.
+ */
+ bind_evtchn_to_cpu(evtchn, cpu, true);
} else {
struct irq_info *info = info_for_irq(irq);
WARN_ON(info == NULL || info->type != IRQT_IPI);
@@ -1281,7 +1314,11 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
goto out;
}
- bind_evtchn_to_cpu(evtchn, cpu);
+ /*
+ * Force the affinity mask for percpu interrupts so proc
+ * shows the correct target.
+ */
+ bind_evtchn_to_cpu(evtchn, cpu, percpu);
} else {
struct irq_info *info = info_for_irq(irq);
WARN_ON(info == NULL || info->type != IRQT_VIRQ);
@@ -1646,9 +1683,7 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq)
mutex_unlock(&irq_mapping_update_lock);
- bind_evtchn_to_cpu(evtchn, info->cpu);
- /* This will be deferred until interrupt is processed */
- irq_set_affinity(irq, cpumask_of(info->cpu));
+ bind_evtchn_to_cpu(evtchn, info->cpu, false);
/* Unmask the event channel. */
enable_irq(irq);
@@ -1682,7 +1717,7 @@ static int xen_rebind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int tcpu)
* it, but don't do the xenlinux-level rebind in that case.
*/
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
- bind_evtchn_to_cpu(evtchn, tcpu);
+ bind_evtchn_to_cpu(evtchn, tcpu, false);
if (!masked)
unmask_evtchn(evtchn);
@@ -1690,27 +1725,47 @@ static int xen_rebind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int tcpu)
return 0;
}
+/*
+ * Find the CPU within @dest mask which has the least number of channels
+ * assigned. This is not precise as the per cpu counts can be modified
+ * concurrently.
+ */
+static unsigned int select_target_cpu(const struct cpumask *dest)
+{
+ unsigned int cpu, best_cpu = UINT_MAX, minch = UINT_MAX;
+
+ for_each_cpu_and(cpu, dest, cpu_online_mask) {
+ unsigned int curch = atomic_read(&channels_on_cpu[cpu]);
+
+ if (curch < minch) {
+ minch = curch;
+ best_cpu = cpu;
+ }
+ }
+
+ /*
+ * Catch the unlikely case that dest contains no online CPUs. Can't
+ * recurse.
+ */
+ if (best_cpu == UINT_MAX)
+ return select_target_cpu(cpu_online_mask);
+
+ return best_cpu;
+}
+
static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
bool force)
{
- unsigned tcpu = cpumask_first_and(dest, cpu_online_mask);
- int ret = xen_rebind_evtchn_to_cpu(evtchn_from_irq(data->irq), tcpu);
+ unsigned int tcpu = select_target_cpu(dest);
+ int ret;
+ ret = xen_rebind_evtchn_to_cpu(evtchn_from_irq(data->irq), tcpu);
if (!ret)
irq_data_update_effective_affinity(data, cpumask_of(tcpu));
return ret;
}
-/* To be called with desc->lock held. */
-int xen_set_affinity_evtchn(struct irq_desc *desc, unsigned int tcpu)
-{
- struct irq_data *d = irq_desc_get_irq_data(desc);
-
- return set_affinity_irq(d, cpumask_of(tcpu), false);
-}
-EXPORT_SYMBOL_GPL(xen_set_affinity_evtchn);
-
static void enable_dynirq(struct irq_data *data)
{
evtchn_port_t evtchn = evtchn_from_irq(data->irq);
@@ -1734,18 +1789,7 @@ static void ack_dynirq(struct irq_data *data)
if (!VALID_EVTCHN(evtchn))
return;
- if (unlikely(irqd_is_setaffinity_pending(data)) &&
- likely(!irqd_irq_disabled(data))) {
- int masked = test_and_set_mask(evtchn);
-
- clear_evtchn(evtchn);
-
- irq_move_masked_irq(data);
-
- if (!masked)
- unmask_evtchn(evtchn);
- } else
- clear_evtchn(evtchn);
+ clear_evtchn(evtchn);
}
static void mask_ack_dynirq(struct irq_data *data)
@@ -1830,7 +1874,8 @@ static void restore_cpu_virqs(unsigned int cpu)
/* Record the new mapping. */
(void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
- bind_evtchn_to_cpu(evtchn, cpu);
+ /* The affinity mask is still valid */
+ bind_evtchn_to_cpu(evtchn, cpu, false);
}
}
@@ -1855,7 +1900,8 @@ static void restore_cpu_ipis(unsigned int cpu)
/* Record the new mapping. */
(void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
- bind_evtchn_to_cpu(evtchn, cpu);
+ /* The affinity mask is still valid */
+ bind_evtchn_to_cpu(evtchn, cpu, false);
}
}
@@ -1938,8 +1984,12 @@ void xen_irq_resume(void)
xen_evtchn_resume();
/* No IRQ <-> event-channel mappings. */
- list_for_each_entry(info, &xen_irq_list_head, list)
- info->evtchn = 0; /* zap event-channel binding */
+ list_for_each_entry(info, &xen_irq_list_head, list) {
+ /* Zap event-channel binding */
+ info->evtchn = 0;
+ /* Adjust accounting */
+ channels_on_cpu_dec(info);
+ }
clear_evtchn_to_irq_all();
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index 5dc016d68f83..a7a85719a8c8 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -421,36 +421,6 @@ static void evtchn_unbind_from_user(struct per_user_data *u,
del_evtchn(u, evtchn);
}
-static DEFINE_PER_CPU(int, bind_last_selected_cpu);
-
-static void evtchn_bind_interdom_next_vcpu(evtchn_port_t evtchn)
-{
- unsigned int selected_cpu, irq;
- struct irq_desc *desc;
- unsigned long flags;
-
- irq = irq_from_evtchn(evtchn);
- desc = irq_to_desc(irq);
-
- if (!desc)
- return;
-
- raw_spin_lock_irqsave(&desc->lock, flags);
- selected_cpu = this_cpu_read(bind_last_selected_cpu);
- selected_cpu = cpumask_next_and(selected_cpu,
- desc->irq_common_data.affinity, cpu_online_mask);
-
- if (unlikely(selected_cpu >= nr_cpu_ids))
- selected_cpu = cpumask_first_and(desc->irq_common_data.affinity,
- cpu_online_mask);
-
- this_cpu_write(bind_last_selected_cpu, selected_cpu);
-
- /* unmask expects irqs to be disabled */
- xen_set_affinity_evtchn(desc, selected_cpu);
- raw_spin_unlock_irqrestore(&desc->lock, flags);
-}
-
static long evtchn_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
@@ -508,10 +478,8 @@ static long evtchn_ioctl(struct file *file,
break;
rc = evtchn_bind_to_user(u, bind_interdomain.local_port);
- if (rc == 0) {
+ if (rc == 0)
rc = bind_interdomain.local_port;
- evtchn_bind_interdom_next_vcpu(rc);
- }
break;
}
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index cd046684e0d1..374d36de7f5a 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -179,6 +179,7 @@ static int poweroff_nb(struct notifier_block *cb, unsigned long code, void *unus
case SYS_HALT:
case SYS_POWER_OFF:
shutting_down = SHUTDOWN_POWEROFF;
+ break;
default:
break;
}
diff --git a/drivers/xen/unpopulated-alloc.c b/drivers/xen/unpopulated-alloc.c
index 7762c1bb23cb..e64e6befc63b 100644
--- a/drivers/xen/unpopulated-alloc.c
+++ b/drivers/xen/unpopulated-alloc.c
@@ -27,11 +27,6 @@ static int fill_list(unsigned int nr_pages)
if (!res)
return -ENOMEM;
- pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
- if (!pgmap)
- goto err_pgmap;
-
- pgmap->type = MEMORY_DEVICE_GENERIC;
res->name = "Xen scratch";
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
@@ -43,6 +38,11 @@ static int fill_list(unsigned int nr_pages)
goto err_resource;
}
+ pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
+ if (!pgmap)
+ goto err_pgmap;
+
+ pgmap->type = MEMORY_DEVICE_GENERIC;
pgmap->range = (struct range) {
.start = res->start,
.end = res->end,
@@ -92,10 +92,10 @@ static int fill_list(unsigned int nr_pages)
return 0;
err_memremap:
- release_resource(res);
-err_resource:
kfree(pgmap);
err_pgmap:
+ release_resource(res);
+err_resource:
kfree(res);
return ret;
}
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index 4b99ec3dec58..e7c692cfb2cf 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -689,7 +689,7 @@ static int xen_pcibk_xenbus_probe(struct xenbus_device *dev,
/* watch the backend node for backend configuration information */
err = xenbus_watch_path(dev, dev->nodename, &pdev->be_watch,
- xen_pcibk_be_watch);
+ NULL, xen_pcibk_be_watch);
if (err)
goto out;
diff --git a/drivers/xen/xenbus/xenbus.h b/drivers/xen/xenbus/xenbus.h
index 5f5b8a7d5b80..2a93b7c9c159 100644
--- a/drivers/xen/xenbus/xenbus.h
+++ b/drivers/xen/xenbus/xenbus.h
@@ -44,6 +44,8 @@ struct xen_bus_type {
int (*get_bus_id)(char bus_id[XEN_BUS_ID_SIZE], const char *nodename);
int (*probe)(struct xen_bus_type *bus, const char *type,
const char *dir);
+ bool (*otherend_will_handle)(struct xenbus_watch *watch,
+ const char *path, const char *token);
void (*otherend_changed)(struct xenbus_watch *watch, const char *path,
const char *token);
struct bus_type bus;
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index fd80e318b99c..0cd728961fce 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -127,18 +127,22 @@ EXPORT_SYMBOL_GPL(xenbus_strstate);
*/
int xenbus_watch_path(struct xenbus_device *dev, const char *path,
struct xenbus_watch *watch,
+ bool (*will_handle)(struct xenbus_watch *,
+ const char *, const char *),
void (*callback)(struct xenbus_watch *,
const char *, const char *))
{
int err;
watch->node = path;
+ watch->will_handle = will_handle;
watch->callback = callback;
err = register_xenbus_watch(watch);
if (err) {
watch->node = NULL;
+ watch->will_handle = NULL;
watch->callback = NULL;
xenbus_dev_fatal(dev, err, "adding watch on %s", path);
}
@@ -165,6 +169,8 @@ EXPORT_SYMBOL_GPL(xenbus_watch_path);
*/
int xenbus_watch_pathfmt(struct xenbus_device *dev,
struct xenbus_watch *watch,
+ bool (*will_handle)(struct xenbus_watch *,
+ const char *, const char *),
void (*callback)(struct xenbus_watch *,
const char *, const char *),
const char *pathfmt, ...)
@@ -181,7 +187,7 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev,
xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch");
return -ENOMEM;
}
- err = xenbus_watch_path(dev, path, watch, callback);
+ err = xenbus_watch_path(dev, path, watch, will_handle, callback);
if (err)
kfree(path);
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 38725d97d909..44634d970a5c 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -136,6 +136,7 @@ static int watch_otherend(struct xenbus_device *dev)
container_of(dev->dev.bus, struct xen_bus_type, bus);
return xenbus_watch_pathfmt(dev, &dev->otherend_watch,
+ bus->otherend_will_handle,
bus->otherend_changed,
"%s/%s", dev->otherend, "state");
}
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index 2ba699897e6d..5abded97e1a7 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -180,6 +180,12 @@ static int xenbus_probe_backend(struct xen_bus_type *bus, const char *type,
return err;
}
+static bool frontend_will_handle(struct xenbus_watch *watch,
+ const char *path, const char *token)
+{
+ return watch->nr_pending == 0;
+}
+
static void frontend_changed(struct xenbus_watch *watch,
const char *path, const char *token)
{
@@ -191,6 +197,7 @@ static struct xen_bus_type xenbus_backend = {
.levels = 3, /* backend/type/<frontend>/<id> */
.get_bus_id = backend_bus_id,
.probe = xenbus_probe_backend,
+ .otherend_will_handle = frontend_will_handle,
.otherend_changed = frontend_changed,
.bus = {
.name = "xen-backend",
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 3a06eb699f33..12e02eb01f59 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -705,9 +705,13 @@ int xs_watch_msg(struct xs_watch_event *event)
spin_lock(&watches_lock);
event->handle = find_watch(event->token);
- if (event->handle != NULL) {
+ if (event->handle != NULL &&
+ (!event->handle->will_handle ||
+ event->handle->will_handle(event->handle,
+ event->path, event->token))) {
spin_lock(&watch_events_lock);
list_add_tail(&event->list, &watch_events);
+ event->handle->nr_pending++;
wake_up(&watch_events_waitq);
spin_unlock(&watch_events_lock);
} else
@@ -765,6 +769,8 @@ int register_xenbus_watch(struct xenbus_watch *watch)
sprintf(token, "%lX", (long)watch);
+ watch->nr_pending = 0;
+
down_read(&xs_watch_rwsem);
spin_lock(&watches_lock);
@@ -814,11 +820,14 @@ void unregister_xenbus_watch(struct xenbus_watch *watch)
/* Cancel pending watch events. */
spin_lock(&watch_events_lock);
- list_for_each_entry_safe(event, tmp, &watch_events, list) {
- if (event->handle != watch)
- continue;
- list_del(&event->list);
- kfree(event);
+ if (watch->nr_pending) {
+ list_for_each_entry_safe(event, tmp, &watch_events, list) {
+ if (event->handle != watch)
+ continue;
+ list_del(&event->list);
+ kfree(event);
+ }
+ watch->nr_pending = 0;
}
spin_unlock(&watch_events_lock);
@@ -865,7 +874,6 @@ void xs_suspend_cancel(void)
static int xenwatch_thread(void *unused)
{
- struct list_head *ent;
struct xs_watch_event *event;
xenwatch_pid = current->pid;
@@ -880,13 +888,15 @@ static int xenwatch_thread(void *unused)
mutex_lock(&xenwatch_mutex);
spin_lock(&watch_events_lock);
- ent = watch_events.next;
- if (ent != &watch_events)
- list_del(ent);
+ event = list_first_entry_or_null(&watch_events,
+ struct xs_watch_event, list);
+ if (event) {
+ list_del(&event->list);
+ event->handle->nr_pending--;
+ }
spin_unlock(&watch_events_lock);
- if (ent != &watch_events) {
- event = list_entry(ent, struct xs_watch_event, list);
+ if (event) {
event->handle->callback(event->handle, event->path,
event->token);
kfree(event);
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