diff options
Diffstat (limited to 'drivers/xen/xenbus')
| -rw-r--r-- | drivers/xen/xenbus/xenbus.h | 2 | ||||
| -rw-r--r-- | drivers/xen/xenbus/xenbus_dev_frontend.c | 20 | ||||
| -rw-r--r-- | drivers/xen/xenbus/xenbus_probe.c | 56 | ||||
| -rw-r--r-- | drivers/xen/xenbus/xenbus_probe_backend.c | 39 | ||||
| -rw-r--r-- | drivers/xen/xenbus/xenbus_probe_frontend.c | 24 |
5 files changed, 108 insertions, 33 deletions
diff --git a/drivers/xen/xenbus/xenbus.h b/drivers/xen/xenbus/xenbus.h index d75a2385b37c..5f5b8a7d5b80 100644 --- a/drivers/xen/xenbus/xenbus.h +++ b/drivers/xen/xenbus/xenbus.h @@ -116,8 +116,6 @@ int xenbus_probe_devices(struct xen_bus_type *bus); void xenbus_dev_changed(const char *node, struct xen_bus_type *bus); -void xenbus_dev_shutdown(struct device *_dev); - int xenbus_dev_suspend(struct device *dev); int xenbus_dev_resume(struct device *dev); int xenbus_dev_cancel(struct device *dev); diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c index 08adc590f631..597af455a522 100644 --- a/drivers/xen/xenbus/xenbus_dev_frontend.c +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c @@ -55,6 +55,7 @@ #include <linux/string.h> #include <linux/slab.h> #include <linux/miscdevice.h> +#include <linux/workqueue.h> #include <xen/xenbus.h> #include <xen/xen.h> @@ -116,6 +117,8 @@ struct xenbus_file_priv { wait_queue_head_t read_waitq; struct kref kref; + + struct work_struct wq; }; /* Read out any raw xenbus messages queued up. */ @@ -300,14 +303,14 @@ static void watch_fired(struct xenbus_watch *watch, mutex_unlock(&adap->dev_data->reply_mutex); } -static void xenbus_file_free(struct kref *kref) +static void xenbus_worker(struct work_struct *wq) { struct xenbus_file_priv *u; struct xenbus_transaction_holder *trans, *tmp; struct watch_adapter *watch, *tmp_watch; struct read_buffer *rb, *tmp_rb; - u = container_of(kref, struct xenbus_file_priv, kref); + u = container_of(wq, struct xenbus_file_priv, wq); /* * No need for locking here because there are no other users, @@ -333,6 +336,18 @@ static void xenbus_file_free(struct kref *kref) kfree(u); } +static void xenbus_file_free(struct kref *kref) +{ + struct xenbus_file_priv *u; + + /* + * We might be called in xenbus_thread(). + * Use workqueue to avoid deadlock. + */ + u = container_of(kref, struct xenbus_file_priv, kref); + schedule_work(&u->wq); +} + static struct xenbus_transaction_holder *xenbus_get_transaction( struct xenbus_file_priv *u, uint32_t tx_id) { @@ -650,6 +665,7 @@ static int xenbus_file_open(struct inode *inode, struct file *filp) INIT_LIST_HEAD(&u->watches); INIT_LIST_HEAD(&u->read_buffers); init_waitqueue_head(&u->read_waitq); + INIT_WORK(&u->wq, xenbus_worker); mutex_init(&u->reply_mutex); mutex_init(&u->msgbuffer_mutex); diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 5b471889d723..66975da4f3b6 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -232,9 +232,18 @@ int xenbus_dev_probe(struct device *_dev) return err; } + if (!try_module_get(drv->driver.owner)) { + dev_warn(&dev->dev, "failed to acquire module reference on '%s'\n", + drv->driver.name); + err = -ESRCH; + goto fail; + } + + spin_lock(&dev->reclaim_lock); err = drv->probe(dev, id); + spin_unlock(&dev->reclaim_lock); if (err) - goto fail; + goto fail_put; err = watch_otherend(dev); if (err) { @@ -244,9 +253,10 @@ int xenbus_dev_probe(struct device *_dev) } return 0; +fail_put: + module_put(drv->driver.owner); fail: xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename); - xenbus_switch_state(dev, XenbusStateClosed); return err; } EXPORT_SYMBOL_GPL(xenbus_dev_probe); @@ -260,39 +270,30 @@ int xenbus_dev_remove(struct device *_dev) free_otherend_watch(dev); - if (drv->remove) + if (drv->remove) { + spin_lock(&dev->reclaim_lock); drv->remove(dev); + spin_unlock(&dev->reclaim_lock); + } + + module_put(drv->driver.owner); free_otherend_details(dev); - xenbus_switch_state(dev, XenbusStateClosed); + /* + * If the toolstack has forced the device state to closing then set + * the state to closed now to allow it to be cleaned up. + * Similarly, if the driver does not support re-bind, set the + * closed. + */ + if (!drv->allow_rebind || + xenbus_read_driver_state(dev->nodename) == XenbusStateClosing) + xenbus_switch_state(dev, XenbusStateClosed); + return 0; } EXPORT_SYMBOL_GPL(xenbus_dev_remove); -void xenbus_dev_shutdown(struct device *_dev) -{ - struct xenbus_device *dev = to_xenbus_device(_dev); - unsigned long timeout = 5*HZ; - - DPRINTK("%s", dev->nodename); - - get_device(&dev->dev); - if (dev->state != XenbusStateConnected) { - pr_info("%s: %s: %s != Connected, skipping\n", - __func__, dev->nodename, xenbus_strstate(dev->state)); - goto out; - } - xenbus_switch_state(dev, XenbusStateClosing); - timeout = wait_for_completion_timeout(&dev->down, timeout); - if (!timeout) - pr_info("%s: %s timeout closing device\n", - __func__, dev->nodename); - out: - put_device(&dev->dev); -} -EXPORT_SYMBOL_GPL(xenbus_dev_shutdown); - int xenbus_register_driver_common(struct xenbus_driver *drv, struct xen_bus_type *bus, struct module *owner, const char *mod_name) @@ -472,6 +473,7 @@ int xenbus_probe_node(struct xen_bus_type *bus, goto fail; dev_set_name(&xendev->dev, "%s", devname); + spin_lock_init(&xendev->reclaim_lock); /* Register with generic device framework. */ err = device_register(&xendev->dev); diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c index b0bed4faf44c..791f6fe01e91 100644 --- a/drivers/xen/xenbus/xenbus_probe_backend.c +++ b/drivers/xen/xenbus/xenbus_probe_backend.c @@ -198,7 +198,6 @@ static struct xen_bus_type xenbus_backend = { .uevent = xenbus_uevent_backend, .probe = xenbus_dev_probe, .remove = xenbus_dev_remove, - .shutdown = xenbus_dev_shutdown, .dev_groups = xenbus_dev_groups, }, }; @@ -248,6 +247,41 @@ static int backend_probe_and_watch(struct notifier_block *notifier, return NOTIFY_DONE; } +static int backend_reclaim_memory(struct device *dev, void *data) +{ + const struct xenbus_driver *drv; + struct xenbus_device *xdev; + + if (!dev->driver) + return 0; + drv = to_xenbus_driver(dev->driver); + if (drv && drv->reclaim_memory) { + xdev = to_xenbus_device(dev); + if (!spin_trylock(&xdev->reclaim_lock)) + return 0; + drv->reclaim_memory(xdev); + spin_unlock(&xdev->reclaim_lock); + } + return 0; +} + +/* + * Returns 0 always because we are using shrinker to only detect memory + * pressure. + */ +static unsigned long backend_shrink_memory_count(struct shrinker *shrinker, + struct shrink_control *sc) +{ + bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, + backend_reclaim_memory); + return 0; +} + +static struct shrinker backend_memory_shrinker = { + .count_objects = backend_shrink_memory_count, + .seeks = DEFAULT_SEEKS, +}; + static int __init xenbus_probe_backend_init(void) { static struct notifier_block xenstore_notifier = { @@ -264,6 +298,9 @@ static int __init xenbus_probe_backend_init(void) register_xenstore_notifier(&xenstore_notifier); + if (register_shrinker(&backend_memory_shrinker)) + pr_warn("shrinker registration failed\n"); + return 0; } subsys_initcall(xenbus_probe_backend_init); diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c index a7d90a719cea..8a1650bbe18f 100644 --- a/drivers/xen/xenbus/xenbus_probe_frontend.c +++ b/drivers/xen/xenbus/xenbus_probe_frontend.c @@ -126,6 +126,28 @@ static int xenbus_frontend_dev_probe(struct device *dev) return xenbus_dev_probe(dev); } +static void xenbus_frontend_dev_shutdown(struct device *_dev) +{ + struct xenbus_device *dev = to_xenbus_device(_dev); + unsigned long timeout = 5*HZ; + + DPRINTK("%s", dev->nodename); + + get_device(&dev->dev); + if (dev->state != XenbusStateConnected) { + pr_info("%s: %s: %s != Connected, skipping\n", + __func__, dev->nodename, xenbus_strstate(dev->state)); + goto out; + } + xenbus_switch_state(dev, XenbusStateClosing); + timeout = wait_for_completion_timeout(&dev->down, timeout); + if (!timeout) + pr_info("%s: %s timeout closing device\n", + __func__, dev->nodename); + out: + put_device(&dev->dev); +} + static const struct dev_pm_ops xenbus_pm_ops = { .suspend = xenbus_dev_suspend, .resume = xenbus_frontend_dev_resume, @@ -146,7 +168,7 @@ static struct xen_bus_type xenbus_frontend = { .uevent = xenbus_uevent_frontend, .probe = xenbus_frontend_dev_probe, .remove = xenbus_dev_remove, - .shutdown = xenbus_dev_shutdown, + .shutdown = xenbus_frontend_dev_shutdown, .dev_groups = xenbus_dev_groups, .pm = &xenbus_pm_ops, |
