Merge with kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6.git/
for 13 driver core, sysfs, and debugfs fixes.
diff --git a/Documentation/kref.txt b/Documentation/kref.txt
new file mode 100644
index 0000000..42fe284
--- /dev/null
+++ b/Documentation/kref.txt
@@ -0,0 +1,216 @@
+
+krefs allow you to add reference counters to your objects. If you
+have objects that are used in multiple places and passed around, and
+you don't have refcounts, your code is almost certainly broken. If
+you want refcounts, krefs are the way to go.
+
+To use a kref, add one to your data structures like:
+
+struct my_data
+{
+ .
+ .
+ struct kref refcount;
+ .
+ .
+};
+
+The kref can occur anywhere within the data structure.
+
+You must initialize the kref after you allocate it. To do this, call
+kref_init as so:
+
+ struct my_data *data;
+
+ data = kmalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ kref_init(&data->refcount);
+
+This sets the refcount in the kref to 1.
+
+Once you have an initialized kref, you must follow the following
+rules:
+
+1) If you make a non-temporary copy of a pointer, especially if
+ it can be passed to another thread of execution, you must
+ increment the refcount with kref_get() before passing it off:
+ kref_get(&data->refcount);
+ If you already have a valid pointer to a kref-ed structure (the
+ refcount cannot go to zero) you may do this without a lock.
+
+2) When you are done with a pointer, you must call kref_put():
+ kref_put(&data->refcount, data_release);
+ If this is the last reference to the pointer, the release
+ routine will be called. If the code never tries to get
+ a valid pointer to a kref-ed structure without already
+ holding a valid pointer, it is safe to do this without
+ a lock.
+
+3) If the code attempts to gain a reference to a kref-ed structure
+ without already holding a valid pointer, it must serialize access
+ where a kref_put() cannot occur during the kref_get(), and the
+ structure must remain valid during the kref_get().
+
+For example, if you allocate some data and then pass it to another
+thread to process:
+
+void data_release(struct kref *ref)
+{
+ struct my_data *data = container_of(ref, struct my_data, refcount);
+ kfree(data);
+}
+
+void more_data_handling(void *cb_data)
+{
+ struct my_data *data = cb_data;
+ .
+ . do stuff with data here
+ .
+ kref_put(data, data_release);
+}
+
+int my_data_handler(void)
+{
+ int rv = 0;
+ struct my_data *data;
+ struct task_struct *task;
+ data = kmalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ kref_init(&data->refcount);
+
+ kref_get(&data->refcount);
+ task = kthread_run(more_data_handling, data, "more_data_handling");
+ if (task == ERR_PTR(-ENOMEM)) {
+ rv = -ENOMEM;
+ kref_put(&data->refcount, data_release);
+ goto out;
+ }
+
+ .
+ . do stuff with data here
+ .
+ out:
+ kref_put(&data->refcount, data_release);
+ return rv;
+}
+
+This way, it doesn't matter what order the two threads handle the
+data, the kref_put() handles knowing when the data is not referenced
+any more and releasing it. The kref_get() does not require a lock,
+since we already have a valid pointer that we own a refcount for. The
+put needs no lock because nothing tries to get the data without
+already holding a pointer.
+
+Note that the "before" in rule 1 is very important. You should never
+do something like:
+
+ task = kthread_run(more_data_handling, data, "more_data_handling");
+ if (task == ERR_PTR(-ENOMEM)) {
+ rv = -ENOMEM;
+ goto out;
+ } else
+ /* BAD BAD BAD - get is after the handoff */
+ kref_get(&data->refcount);
+
+Don't assume you know what you are doing and use the above construct.
+First of all, you may not know what you are doing. Second, you may
+know what you are doing (there are some situations where locking is
+involved where the above may be legal) but someone else who doesn't
+know what they are doing may change the code or copy the code. It's
+bad style. Don't do it.
+
+There are some situations where you can optimize the gets and puts.
+For instance, if you are done with an object and enqueuing it for
+something else or passing it off to something else, there is no reason
+to do a get then a put:
+
+ /* Silly extra get and put */
+ kref_get(&obj->ref);
+ enqueue(obj);
+ kref_put(&obj->ref, obj_cleanup);
+
+Just do the enqueue. A comment about this is always welcome:
+
+ enqueue(obj);
+ /* We are done with obj, so we pass our refcount off
+ to the queue. DON'T TOUCH obj AFTER HERE! */
+
+The last rule (rule 3) is the nastiest one to handle. Say, for
+instance, you have a list of items that are each kref-ed, and you wish
+to get the first one. You can't just pull the first item off the list
+and kref_get() it. That violates rule 3 because you are not already
+holding a valid pointer. You must add locks or semaphores. For
+instance:
+
+static DECLARE_MUTEX(sem);
+static LIST_HEAD(q);
+struct my_data
+{
+ struct kref refcount;
+ struct list_head link;
+};
+
+static struct my_data *get_entry()
+{
+ struct my_data *entry = NULL;
+ down(&sem);
+ if (!list_empty(&q)) {
+ entry = container_of(q.next, struct my_q_entry, link);
+ kref_get(&entry->refcount);
+ }
+ up(&sem);
+ return entry;
+}
+
+static void release_entry(struct kref *ref)
+{
+ struct my_data *entry = container_of(ref, struct my_data, refcount);
+
+ list_del(&entry->link);
+ kfree(entry);
+}
+
+static void put_entry(struct my_data *entry)
+{
+ down(&sem);
+ kref_put(&entry->refcount, release_entry);
+ up(&sem);
+}
+
+The kref_put() return value is useful if you do not want to hold the
+lock during the whole release operation. Say you didn't want to call
+kfree() with the lock held in the example above (since it is kind of
+pointless to do so). You could use kref_put() as follows:
+
+static void release_entry(struct kref *ref)
+{
+ /* All work is done after the return from kref_put(). */
+}
+
+static void put_entry(struct my_data *entry)
+{
+ down(&sem);
+ if (kref_put(&entry->refcount, release_entry)) {
+ list_del(&entry->link);
+ up(&sem);
+ kfree(entry);
+ } else
+ up(&sem);
+}
+
+This is really more useful if you have to call other routines as part
+of the free operations that could take a long time or might claim the
+same lock. Note that doing everything in the release routine is still
+preferred as it is a little neater.
+
+
+Corey Minyard <minyard@acm.org>
+
+A lot of this was lifted from Greg Kroah-Hartman's 2004 OLS paper and
+presentation on krefs, which can be found at:
+ http://www.kroah.com/linux/talks/ols_2004_kref_paper/Reprint-Kroah-Hartman-OLS2004.pdf
+and:
+ http://www.kroah.com/linux/talks/ols_2004_kref_talk/
+
diff --git a/drivers/base/class.c b/drivers/base/class.c
index 6bf650f..d2a2f8f 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -430,6 +430,7 @@
sysfs_create_link(&class_dev->kobj,
&class_dev->dev->kobj, "device");
+ kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
register_done:
if (error && parent)
class_put(parent);
@@ -461,6 +462,7 @@
sysfs_remove_link(&class_dev->kobj, "device");
class_device_remove_attrs(class_dev);
+ kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
kobject_del(&class_dev->kobj);
if (parent)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 4e6cce8..a7cedd8 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -260,6 +260,8 @@
/* notify platform of device entry */
if (platform_notify)
platform_notify(dev);
+
+ kobject_hotplug(&dev->kobj, KOBJ_ADD);
Done:
put_device(dev);
return error;
@@ -349,6 +351,7 @@
platform_notify_remove(dev);
bus_remove_device(dev);
device_pm_remove(dev);
+ kobject_hotplug(&dev->kobj, KOBJ_REMOVE);
kobject_del(&dev->kobj);
if (parent)
put_device(parent);
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 26c9464..97fe13f 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -102,6 +102,9 @@
if (add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size, &len,
"FIRMWARE=%s", fw_priv->fw_id))
return -ENOMEM;
+ if (add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size, &len,
+ "TIMEOUT=%i", loading_timeout))
+ return -ENOMEM;
envp[i] = NULL;
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 996cbb4..cd64539 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -341,6 +341,7 @@
EXPORT_SYMBOL_GPL(platform_bus);
EXPORT_SYMBOL_GPL(platform_bus_type);
+EXPORT_SYMBOL_GPL(platform_add_devices);
EXPORT_SYMBOL_GPL(platform_device_register);
EXPORT_SYMBOL_GPL(platform_device_register_simple);
EXPORT_SYMBOL_GPL(platform_device_unregister);
diff --git a/drivers/usb/host/hc_crisv10.c b/drivers/usb/host/hc_crisv10.c
index 4b12be8..376f8a0 100644
--- a/drivers/usb/host/hc_crisv10.c
+++ b/drivers/usb/host/hc_crisv10.c
@@ -4396,6 +4396,7 @@
device_initialize(&fake_device);
kobject_set_name(&fake_device.kobj, "etrax_usb");
kobject_add(&fake_device.kobj);
+ kobject_hotplug(&fake_device.kobj, KOBJ_ADD);
hc->bus->controller = &fake_device;
usb_register_bus(hc->bus);
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 31cff78..2cab98a 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -337,6 +337,7 @@
if ((err = kobject_add(&disk->kobj)))
return;
disk_sysfs_symlinks(disk);
+ kobject_hotplug(&disk->kobj, KOBJ_ADD);
/* No minors to use for partitions */
if (disk->minors == 1) {
@@ -441,5 +442,6 @@
sysfs_remove_link(&disk->driverfs_dev->kobj, "block");
put_device(disk->driverfs_dev);
}
+ kobject_hotplug(&disk->kobj, KOBJ_REMOVE);
kobject_del(&disk->kobj);
}
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 352f966..da25aeb 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -428,6 +428,41 @@
/**
+ * sysfs_chmod_file - update the modified mode value on an object attribute.
+ * @kobj: object we're acting for.
+ * @attr: attribute descriptor.
+ * @mode: file permissions.
+ *
+ */
+int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
+{
+ struct dentry *dir = kobj->dentry;
+ struct dentry *victim;
+ struct sysfs_dirent *sd;
+ umode_t umode = (mode & S_IALLUGO) | S_IFREG;
+ int res = -ENOENT;
+
+ down(&dir->d_inode->i_sem);
+ victim = sysfs_get_dentry(dir, attr->name);
+ if (!IS_ERR(victim)) {
+ if (victim->d_inode &&
+ (victim->d_parent->d_inode == dir->d_inode)) {
+ sd = victim->d_fsdata;
+ attr->mode = mode;
+ sd->s_mode = umode;
+ victim->d_inode->i_mode = umode;
+ dput(victim);
+ res = 0;
+ }
+ }
+ up(&dir->d_inode->i_sem);
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(sysfs_chmod_file);
+
+
+/**
* sysfs_remove_file - remove an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index f7a7b86..a5fa6a6 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -17,6 +17,10 @@
#include <linux/fs.h>
+#include <linux/types.h>
+
+struct file_operations;
+
#if defined(CONFIG_DEBUG_FS)
struct dentry *debugfs_create_file(const char *name, mode_t mode,
struct dentry *parent, void *data,
@@ -36,6 +40,9 @@
struct dentry *parent, u32 *value);
#else
+
+#include <linux/err.h>
+
/*
* We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
* so users have a chance to detect if there was a real error or not. We don't
@@ -68,21 +75,21 @@
static inline struct dentry *debugfs_create_u16(const char *name, mode_t mode,
struct dentry *parent,
- u8 *value)
+ u16 *value)
{
return ERR_PTR(-ENODEV);
}
static inline struct dentry *debugfs_create_u32(const char *name, mode_t mode,
struct dentry *parent,
- u8 *value)
+ u32 *value)
{
return ERR_PTR(-ENODEV);
}
static inline struct dentry *debugfs_create_bool(const char *name, mode_t mode,
struct dentry *parent,
- u8 *value)
+ u32 *value)
{
return ERR_PTR(-ENODEV);
}
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 6f502ff..38b58b3 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -99,6 +99,9 @@
extern int
sysfs_update_file(struct kobject *, const struct attribute *);
+extern int
+sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode);
+
extern void
sysfs_remove_file(struct kobject *, const struct attribute *);
@@ -140,6 +143,10 @@
{
return 0;
}
+static inline int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
+{
+ return 0;
+}
static inline void sysfs_remove_file(struct kobject * k, const struct attribute * a)
{
diff --git a/lib/kobject.c b/lib/kobject.c
index ff94919..5df8441 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -184,8 +184,6 @@
unlink(kobj);
if (parent)
kobject_put(parent);
- } else {
- kobject_hotplug(kobj, KOBJ_ADD);
}
return error;
@@ -207,7 +205,8 @@
printk("kobject_register failed for %s (%d)\n",
kobject_name(kobj),error);
dump_stack();
- }
+ } else
+ kobject_hotplug(kobj, KOBJ_ADD);
} else
error = -EINVAL;
return error;
@@ -301,7 +300,6 @@
void kobject_del(struct kobject * kobj)
{
- kobject_hotplug(kobj, KOBJ_REMOVE);
sysfs_remove_dir(kobj);
unlink(kobj);
}
@@ -314,6 +312,7 @@
void kobject_unregister(struct kobject * kobj)
{
pr_debug("kobject %s: unregistering\n",kobject_name(kobj));
+ kobject_hotplug(kobj, KOBJ_REMOVE);
kobject_del(kobj);
kobject_put(kobj);
}
diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
index 567249b..f6a19d5 100644
--- a/net/bridge/br_sysfs_if.c
+++ b/net/bridge/br_sysfs_if.c
@@ -248,6 +248,7 @@
if (err)
goto out2;
+ kobject_hotplug(&p->kobj, KOBJ_ADD);
return 0;
out2:
kobject_del(&p->kobj);
@@ -259,6 +260,7 @@
{
pr_debug("br_sysfs_removeif\n");
sysfs_remove_link(&p->br->ifobj, p->dev->name);
+ kobject_hotplug(&p->kobj, KOBJ_REMOVE);
kobject_del(&p->kobj);
}
diff --git a/scripts/ver_linux b/scripts/ver_linux
index bb195a1..a28c279 100755
--- a/scripts/ver_linux
+++ b/scripts/ver_linux
@@ -87,7 +87,7 @@
expr --v 2>&1 | awk 'NR==1{print "Sh-utils ", $NF}'
-udevinfo -V | awk '{print "udev ", $3}'
+udevinfo -V 2>&1 | grep version | awk '{print "udev ", $3}'
if [ -e /proc/modules ]; then
X=`cat /proc/modules | sed -e "s/ .*$//"`