One important point cannot be overstated: every kobject must have a
release() method, and the kobject must persist (in a consistent state)
until that method is called. If these constraints are not met, the code is
-flawed. Note that the kernel will warn you if you forget to provide a
+flawed. Note that the kernel will warn you if you forget to provide a
release() method. Do not try to get rid of this warning by providing an
-"empty" release function; you will be mocked mercilessly by the kobject
-maintainer if you attempt this.
+"empty" release function.
+
+If all your cleanup function needs to do is call kfree(), then you must
+create a wrapper function which uses container_of() to upcast to the correct
+type (as shown in the example above) and then calls kfree() on the overall
+structure.
Note, the name of the kobject is available in the release function, but it
must NOT be changed within this callback. Otherwise there will be a memory
#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
+#define DRIVER_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
+ struct driver_attribute driver_attr_##_name = \
+ __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
static int __must_check bus_rescan_devices_helper(struct device *dev,
void *data);
bus_put(bus);
return err;
}
-static DRIVER_ATTR_WO(unbind);
+static DRIVER_ATTR_IGNORE_LOCKDEP(unbind, S_IWUSR, NULL, unbind_store);
/*
* Manually attach a device to a driver.
bus_put(bus);
return err;
}
-static DRIVER_ATTR_WO(bind);
+static DRIVER_ATTR_IGNORE_LOCKDEP(bind, S_IWUSR, NULL, bind_store);
static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
{
static ssize_t uevent_store(struct device_driver *drv, const char *buf,
size_t count)
{
- kobject_synth_uevent(&drv->p->kobj, buf, count);
- return count;
+ int rc;
+
+ rc = kobject_synth_uevent(&drv->p->kobj, buf, count);
+ return rc ? rc : count;
}
static DRIVER_ATTR_WO(uevent);
static ssize_t bus_uevent_store(struct bus_type *bus,
const char *buf, size_t count)
{
- kobject_synth_uevent(&bus->p->subsys.kobj, buf, count);
- return count;
+ int rc;
+
+ rc = kobject_synth_uevent(&bus->p->subsys.kobj, buf, count);
+ return rc ? rc : count;
}
static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
return 0;
}
-static int component_devices_open(struct inode *inode, struct file *file)
-{
- return single_open(file, component_devices_show, inode->i_private);
-}
-
-static const struct file_operations component_devices_fops = {
- .open = component_devices_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(component_devices);
static int __init component_debug_init(void)
{
const char *buf, size_t size)
{
struct dev_ext_attribute *ea = to_ext_attr(attr);
- char *end;
- unsigned long new = simple_strtoul(buf, &end, 0);
- if (end == buf)
- return -EINVAL;
+ int ret;
+ unsigned long new;
+
+ ret = kstrtoul(buf, 0, &new);
+ if (ret)
+ return ret;
*(unsigned long *)(ea->var) = new;
/* Always return full write size even if we didn't consume all */
return size;
const char *buf, size_t size)
{
struct dev_ext_attribute *ea = to_ext_attr(attr);
- char *end;
- long new = simple_strtol(buf, &end, 0);
- if (end == buf || new > INT_MAX || new < INT_MIN)
+ int ret;
+ long new;
+
+ ret = kstrtol(buf, 0, &new);
+ if (ret)
+ return ret;
+
+ if (new > INT_MAX || new < INT_MIN)
return -EINVAL;
*(int *)(ea->var) = new;
/* Always return full write size even if we didn't consume all */
else if (dev->class && dev->class->dev_release)
dev->class->dev_release(dev);
else
- WARN(1, KERN_ERR "Device '%s' does not have a release() "
- "function, it is broken and must be fixed.\n",
+ WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt.\n",
dev_name(dev));
kfree(p);
}
static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
- if (kobject_synth_uevent(&dev->kobj, buf, count))
+ int rc;
+
+ rc = kobject_synth_uevent(&dev->kobj, buf, count);
+
+ if (rc) {
dev_err(dev, "uevent: failed to send synthetic uevent\n");
+ return rc;
+ }
return count;
}
}
/**
- * device_block_probing() - Block/defere device's probes
+ * device_block_probing() - Block/defer device's probes
*
* It will disable probing of devices and defer their probes instead.
*/
static int deferred_probe_timeout = -1;
static int __init deferred_probe_timeout_setup(char *str)
{
- deferred_probe_timeout = simple_strtol(str, NULL, 10);
+ int timeout;
+
+ if (!kstrtoint(str, 10, &timeout))
+ deferred_probe_timeout = timeout;
return 1;
}
__setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
if (defer_all_probes) {
/*
* Value of defer_all_probes can be set only by
- * device_defer_all_probes_enable() which, in turn, will call
+ * device_block_probing() which, in turn, will call
* wait_for_device_probe() right after that to avoid any races.
*/
dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);
drv = dev->driver;
if (drv) {
- if (driver_allows_async_probing(drv))
- async_synchronize_full();
-
while (device_links_busy(dev)) {
device_unlock(dev);
- if (parent)
+ if (parent && dev->bus->need_parent_lock)
device_unlock(parent);
device_links_unbind_consumers(dev);
- if (parent)
+ if (parent && dev->bus->need_parent_lock)
device_lock(parent);
device_lock(dev);
struct device_private *dev_prv;
struct device *dev;
+ if (driver_allows_async_probing(drv))
+ async_synchronize_full();
+
for (;;) {
spin_lock(&drv->p->klist_devices.k_lock);
if (list_empty(&drv->p->klist_devices.k_list)) {
* uses.
*/
-static ssize_t show_mem_start_phys_index(struct device *dev,
- struct device_attribute *attr, char *buf)
+static ssize_t phys_index_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
struct memory_block *mem = to_memory_block(dev);
unsigned long phys_index;
/*
* Show whether the section of memory is likely to be hot-removable
*/
-static ssize_t show_mem_removable(struct device *dev,
- struct device_attribute *attr, char *buf)
+static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
unsigned long i, pfn;
int ret = 1;
/*
* online, offline, going offline, etc.
*/
-static ssize_t show_mem_state(struct device *dev,
- struct device_attribute *attr, char *buf)
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
struct memory_block *mem = to_memory_block(dev);
ssize_t len = 0;
return 0;
/*
- * If we are called from store_mem_state(), online_type will be
+ * If we are called from state_store(), online_type will be
* set >= 0 Otherwise we were called from the device online
* attribute and need to set the online_type.
*/
return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
}
-static ssize_t
-store_mem_state(struct device *dev,
- struct device_attribute *attr, const char *buf, size_t count)
+static ssize_t state_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
{
struct memory_block *mem = to_memory_block(dev);
int ret, online_type;
* s.t. if I offline all of these sections I can then
* remove the physical device?
*/
-static ssize_t show_phys_device(struct device *dev,
+static ssize_t phys_device_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct memory_block *mem = to_memory_block(dev);
}
}
-static ssize_t show_valid_zones(struct device *dev,
+static ssize_t valid_zones_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct memory_block *mem = to_memory_block(dev);
return strlen(buf);
}
-static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL);
+static DEVICE_ATTR_RO(valid_zones);
#endif
-static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
-static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state);
-static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL);
-static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL);
+static DEVICE_ATTR_RO(phys_index);
+static DEVICE_ATTR_RW(state);
+static DEVICE_ATTR_RO(phys_device);
+static DEVICE_ATTR_RO(removable);
/*
* Block size attribute stuff
*/
-static ssize_t
-print_block_size(struct device *dev, struct device_attribute *attr,
- char *buf)
+static ssize_t block_size_bytes_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%lx\n", get_memory_block_size());
}
-static DEVICE_ATTR(block_size_bytes, 0444, print_block_size, NULL);
+static DEVICE_ATTR_RO(block_size_bytes);
/*
* Memory auto online policy.
*/
-static ssize_t
-show_auto_online_blocks(struct device *dev, struct device_attribute *attr,
- char *buf)
+static ssize_t auto_online_blocks_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
if (memhp_auto_online)
return sprintf(buf, "online\n");
return sprintf(buf, "offline\n");
}
-static ssize_t
-store_auto_online_blocks(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t auto_online_blocks_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
{
if (sysfs_streq(buf, "online"))
memhp_auto_online = true;
return count;
}
-static DEVICE_ATTR(auto_online_blocks, 0644, show_auto_online_blocks,
- store_auto_online_blocks);
+static DEVICE_ATTR_RW(auto_online_blocks);
/*
* Some architectures will have custom drivers to do this, and
* and will require this interface.
*/
#ifdef CONFIG_ARCH_MEMORY_PROBE
-static ssize_t
-memory_probe_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
{
u64 phys_addr;
int nid, ret;
return ret;
}
-static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
+static DEVICE_ATTR_WO(probe);
#endif
#ifdef CONFIG_MEMORY_FAILURE
*/
/* Soft offline a page */
-static ssize_t
-store_soft_offline_page(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t soft_offline_page_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
{
int ret;
u64 pfn;
}
/* Forcibly offline a page, including killing processes. */
-static ssize_t
-store_hard_offline_page(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t hard_offline_page_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
{
int ret;
u64 pfn;
return ret ? ret : count;
}
-static DEVICE_ATTR(soft_offline_page, S_IWUSR, NULL, store_soft_offline_page);
-static DEVICE_ATTR(hard_offline_page, S_IWUSR, NULL, store_hard_offline_page);
+static DEVICE_ATTR_WO(soft_offline_page);
+static DEVICE_ATTR_WO(hard_offline_page);
#endif
/*
{
BUG_ON(memory->dev.bus != &memory_subsys);
- /* drop the ref. we got in remove_memory_block() */
+ /* drop the ref. we got in remove_memory_section() */
put_device(&memory->dev);
device_unregister(&memory->dev);
}
*/
void platform_device_put(struct platform_device *pdev)
{
- if (pdev)
+ if (!IS_ERR_OR_NULL(pdev))
put_device(&pdev->dev);
}
EXPORT_SYMBOL_GPL(platform_device_put);
{
int i;
- if (pdev) {
+ if (!IS_ERR_OR_NULL(pdev)) {
device_del(&pdev->dev);
if (pdev->id_auto) {
static void kernfs_notify_workfn(struct work_struct *work)
{
struct kernfs_node *kn;
- struct kernfs_open_node *on;
struct kernfs_super_info *info;
repeat:
/* pop one off the notify_list */
kn->attr.notify_next = NULL;
spin_unlock_irq(&kernfs_notify_lock);
- /* kick poll */
- spin_lock_irq(&kernfs_open_node_lock);
-
- on = kn->attr.open;
- if (on) {
- atomic_inc(&on->event);
- wake_up_interruptible(&on->poll);
- }
-
- spin_unlock_irq(&kernfs_open_node_lock);
-
/* kick fsnotify */
mutex_lock(&kernfs_mutex);
{
static DECLARE_WORK(kernfs_notify_work, kernfs_notify_workfn);
unsigned long flags;
+ struct kernfs_open_node *on;
if (WARN_ON(kernfs_type(kn) != KERNFS_FILE))
return;
+ /* kick poll immediately */
+ spin_lock_irqsave(&kernfs_open_node_lock, flags);
+ on = kn->attr.open;
+ if (on) {
+ atomic_inc(&on->event);
+ wake_up_interruptible(&on->poll);
+ }
+ spin_unlock_irqrestore(&kernfs_open_node_lock, flags);
+
+ /* schedule work to kick fsnotify */
spin_lock_irqsave(&kernfs_notify_lock, flags);
if (!kn->attr.notify_next) {
kernfs_get(kn);
* @release: pointer to the function that will clean up the object when the
* last reference to the object is released.
* This pointer is required, and it is not acceptable to pass kfree
- * in as this function. If the caller does pass kfree to this
- * function, you will be publicly mocked mercilessly by the kref
- * maintainer, and anyone else who happens to notice it. You have
- * been warned.
+ * in as this function.
*
* Decrement the refcount, and if 0, call release().
* Return 1 if the object was removed, otherwise return 0. Beware, if this
struct module_kobject *mk,
const char *buffer, size_t count)
{
- kobject_synth_uevent(&mk->kobj, buffer, count);
- return count;
+ int rc;
+
+ rc = kobject_synth_uevent(&mk->kobj, buffer, count);
+ return rc ? rc : count;
}
struct module_attribute module_uevent =
kobject_name(kobj), kobj, __func__, kobj->parent);
if (t && !t->release)
- pr_debug("kobject: '%s' (%p): does not have a release() function, it is broken and must be fixed.\n",
+ pr_debug("kobject: '%s' (%p): does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt.\n",
kobject_name(kobj), kobj);
/* send "remove" if the caller did not do it but sent "add" */
ops = kobj_ns_ops(kobj);
if (ops) {
const void *init_ns, *ns;
+
ns = kobj->ktype->namespace(kobj);
init_ns = ops->initial_ns();
return ns != init_ns;
ops = kobj_ns_ops(kobj);
if (!ops && kobj->kset) {
struct kobject *ksobj = &kobj->kset->kobj;
+
if (ksobj->parent != NULL)
ops = kobj_ns_ops(ksobj->parent);
}
mutex_lock(&uevent_sock_mutex);
/* we will send an event, so request a new sequence number */
- retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
+ retval = add_uevent_var(env, "SEQNUM=%llu", ++uevent_seqnum);
if (retval) {
mutex_unlock(&uevent_sock_mutex);
goto exit;