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Driver core patches for 3.11-rc2

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Here are some driver core patches for 3.11-rc2.  They aren't really
 bugfixes, but a bunch of new helper macros for drivers to properly
 create attribute groups, which drivers and subsystems need to fix up a
 ton of race issues with incorrectly creating sysfs files (binary and
 normal) after userspace has been told that the device is present.
 
 Also here is the ability to create binary files as attribute groups, to
 solve that race condition, which was impossible to do before this, so
 that's my fault the drivers were broken.
 
 The majority of the .c changes is indenting and moving code around a
 bit.  It affects no existing code, but allows the large backlog of 70+
 patches that I already have created to start flowing into the different
 subtrees, instead of having to live in my driver-core tree, causing
 merge nightmares in linux-next for the next few months.
 
 These were finalized too late for the -rc1 merge window, which is why
 they were didn't make that pull request, testing and review from others
 didn't happen until a few weeks ago, and then there's the whole
 distraction of the past few days, which prevented these from getting to
 you sooner, sorry about that.
 
 Oh, and there's a bugfix for the documentation build warning in here as
 well.  All of these have been in linux-next this week, with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core patches from Greg KH:
 "Here are some driver core patches for 3.11-rc2.  They aren't really
  bugfixes, but a bunch of new helper macros for drivers to properly
  create attribute groups, which drivers and subsystems need to fix up a
  ton of race issues with incorrectly creating sysfs files (binary and
  normal) after userspace has been told that the device is present.

  Also here is the ability to create binary files as attribute groups,
  to solve that race condition, which was impossible to do before this,
  so that's my fault the drivers were broken.

  The majority of the .c changes is indenting and moving code around a
  bit.  It affects no existing code, but allows the large backlog of 70+
  patches that I already have created to start flowing into the
  different subtrees, instead of having to live in my driver-core tree,
  causing merge nightmares in linux-next for the next few months.

  These were finalized too late for the -rc1 merge window, which is why
  they were didn't make that pull request, testing and review from
  others didn't happen until a few weeks ago, and then there's the whole
  distraction of the past few days, which prevented these from getting
  to you sooner, sorry about that.

  Oh, and there's a bugfix for the documentation build warning in here
  as well.  All of these have been in linux-next this week, with no
  reported problems"

* tag 'driver-core-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver-core: fix new kernel-doc warning in base/platform.c
  sysfs: use file mode defines from stat.h
  sysfs: add more helper macro's for (bin_)attribute(_groups)
  driver core: add default groups to struct class
  driver core: Introduce device_create_groups
  sysfs: prevent warning when only using binary attributes
  sysfs: add support for binary attributes in groups
  driver core: device.h: add RW and RO attribute macros
  sysfs.h: add BIN_ATTR macro
  sysfs.h: add ATTRIBUTE_GROUPS() macro
  sysfs.h: add __ATTR_RW() macro
This commit is contained in:
Linus Torvalds 2013-07-18 12:48:40 -07:00
commit 7a62711aac
7 changed files with 227 additions and 75 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

126
drivers/base/core.c
View File

@ -528,9 +528,12 @@ static int device_add_attrs(struct device *dev)
int error;
if (class) {
error = device_add_attributes(dev, class->dev_attrs);
error = device_add_groups(dev, class->dev_groups);
if (error)
return error;
error = device_add_attributes(dev, class->dev_attrs);
if (error)
goto err_remove_class_groups;
error = device_add_bin_attributes(dev, class->dev_bin_attrs);
if (error)
goto err_remove_class_attrs;
@ -563,6 +566,9 @@ static int device_add_attrs(struct device *dev)
err_remove_class_attrs:
if (class)
device_remove_attributes(dev, class->dev_attrs);
err_remove_class_groups:
if (class)
device_remove_groups(dev, class->dev_groups);
return error;
}
@ -581,6 +587,7 @@ static void device_remove_attrs(struct device *dev)
if (class) {
device_remove_attributes(dev, class->dev_attrs);
device_remove_bin_attributes(dev, class->dev_bin_attrs);
device_remove_groups(dev, class->dev_groups);
}
}
@ -1667,6 +1674,46 @@ static void device_create_release(struct device *dev)
kfree(dev);
}
static struct device *
device_create_groups_vargs(struct class *class, struct device *parent,
dev_t devt, void *drvdata,
const struct attribute_group **groups,
const char *fmt, va_list args)
{
struct device *dev = NULL;
int retval = -ENODEV;
if (class == NULL || IS_ERR(class))
goto error;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev) {
retval = -ENOMEM;
goto error;
}
dev->devt = devt;
dev->class = class;
dev->parent = parent;
dev->groups = groups;
dev->release = device_create_release;
dev_set_drvdata(dev, drvdata);
retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
if (retval)
goto error;
retval = device_register(dev);
if (retval)
goto error;
return dev;
error:
put_device(dev);
return ERR_PTR(retval);
}
/**
* device_create_vargs - creates a device and registers it with sysfs
* @class: pointer to the struct class that this device should be registered to
@ -1696,37 +1743,8 @@ struct device *device_create_vargs(struct class *class, struct device *parent,
dev_t devt, void *drvdata, const char *fmt,
va_list args)
{
struct device *dev = NULL;
int retval = -ENODEV;
if (class == NULL || IS_ERR(class))
goto error;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev) {
retval = -ENOMEM;
goto error;
}
dev->devt = devt;
dev->class = class;
dev->parent = parent;
dev->release = device_create_release;
dev_set_drvdata(dev, drvdata);
retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
if (retval)
goto error;
retval = device_register(dev);
if (retval)
goto error;
return dev;
error:
put_device(dev);
return ERR_PTR(retval);
return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
fmt, args);
}
EXPORT_SYMBOL_GPL(device_create_vargs);
@ -1767,6 +1785,50 @@ struct device *device_create(struct class *class, struct device *parent,
}
EXPORT_SYMBOL_GPL(device_create);
/**
* device_create_with_groups - creates a device and registers it with sysfs
* @class: pointer to the struct class that this device should be registered to
* @parent: pointer to the parent struct device of this new device, if any
* @devt: the dev_t for the char device to be added
* @drvdata: the data to be added to the device for callbacks
* @groups: NULL-terminated list of attribute groups to be created
* @fmt: string for the device's name
*
* This function can be used by char device classes. A struct device
* will be created in sysfs, registered to the specified class.
* Additional attributes specified in the groups parameter will also
* be created automatically.
*
* A "dev" file will be created, showing the dev_t for the device, if
* the dev_t is not 0,0.
* If a pointer to a parent struct device is passed in, the newly created
* struct device will be a child of that device in sysfs.
* The pointer to the struct device will be returned from the call.
* Any further sysfs files that might be required can be created using this
* pointer.
*
* Returns &struct device pointer on success, or ERR_PTR() on error.
*
* Note: the struct class passed to this function must have previously
* been created with a call to class_create().
*/
struct device *device_create_with_groups(struct class *class,
struct device *parent, dev_t devt,
void *drvdata,
const struct attribute_group **groups,
const char *fmt, ...)
{
va_list vargs;
struct device *dev;
va_start(vargs, fmt);
dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
fmt, vargs);
va_end(vargs);
return dev;
}
EXPORT_SYMBOL_GPL(device_create_with_groups);
static int __match_devt(struct device *dev, const void *data)
{
const dev_t *devt = data;

1
drivers/base/platform.c
View File

@ -522,6 +522,7 @@ static void platform_drv_shutdown(struct device *_dev)
/**
* __platform_driver_register - register a driver for platform-level devices
* @drv: platform driver structure
* @owner: owning module/driver
*/
int __platform_driver_register(struct platform_driver *drv,
struct module *owner)

70
fs/sysfs/group.c
View File

@ -20,38 +20,64 @@ static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
const struct attribute_group *grp)
{
struct attribute *const* attr;
int i;
struct bin_attribute *const* bin_attr;
for (i = 0, attr = grp->attrs; *attr; i++, attr++)
sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
if (grp->attrs)
for (attr = grp->attrs; *attr; attr++)
sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
if (grp->bin_attrs)
for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++)
sysfs_remove_bin_file(kobj, *bin_attr);
}
static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
const struct attribute_group *grp, int update)
{
struct attribute *const* attr;
struct bin_attribute *const* bin_attr;
int error = 0, i;
for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
umode_t mode = 0;
if (grp->attrs) {
for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
umode_t mode = 0;
/* in update mode, we're changing the permissions or
* visibility. Do this by first removing then
* re-adding (if required) the file */
if (update)
sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
if (grp->is_visible) {
mode = grp->is_visible(kobj, *attr, i);
if (!mode)
continue;
/*
* In update mode, we're changing the permissions or
* visibility. Do this by first removing then
* re-adding (if required) the file.
*/
if (update)
sysfs_hash_and_remove(dir_sd, NULL,
(*attr)->name);
if (grp->is_visible) {
mode = grp->is_visible(kobj, *attr, i);
if (!mode)
continue;
}
error = sysfs_add_file_mode(dir_sd, *attr,
SYSFS_KOBJ_ATTR,
(*attr)->mode | mode);
if (unlikely(error))
break;
}
if (error) {
remove_files(dir_sd, kobj, grp);
goto exit;
}
error = sysfs_add_file_mode(dir_sd, *attr, SYSFS_KOBJ_ATTR,
(*attr)->mode | mode);
if (unlikely(error))
break;
}
if (error)
remove_files(dir_sd, kobj, grp);
if (grp->bin_attrs) {
for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
if (update)
sysfs_remove_bin_file(kobj, *bin_attr);
error = sysfs_create_bin_file(kobj, *bin_attr);
if (error)
break;
}
if (error)
remove_files(dir_sd, kobj, grp);
}
exit:
return error;
}
@ -67,8 +93,8 @@ static int internal_create_group(struct kobject *kobj, int update,
/* Updates may happen before the object has been instantiated */
if (unlikely(update && !kobj->sd))
return -EINVAL;
if (!grp->attrs) {
WARN(1, "sysfs: attrs not set by subsystem for group: %s/%s\n",
if (!grp->attrs && !grp->bin_attrs) {
WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
kobj->name, grp->name ? "" : grp->name);
return -EINVAL;
}

37
include/linux/device.h
View File

@ -47,7 +47,11 @@ struct bus_attribute {
};
#define BUS_ATTR(_name, _mode, _show, _store) \
struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
#define BUS_ATTR_RW(_name) \
struct bus_attribute bus_attr_##_name = __ATTR_RW(_name)
#define BUS_ATTR_RO(_name) \
struct bus_attribute bus_attr_##_name = __ATTR_RO(_name)
extern int __must_check bus_create_file(struct bus_type *,
struct bus_attribute *);
@ -261,9 +265,12 @@ struct driver_attribute {
size_t count);
};
#define DRIVER_ATTR(_name, _mode, _show, _store) \
struct driver_attribute driver_attr_##_name = \
__ATTR(_name, _mode, _show, _store)
#define DRIVER_ATTR(_name, _mode, _show, _store) \
struct driver_attribute driver_attr_##_name = __ATTR(_name, _mode, _show, _store)
#define DRIVER_ATTR_RW(_name) \
struct driver_attribute driver_attr_##_name = __ATTR_RW(_name)
#define DRIVER_ATTR_RO(_name) \
struct driver_attribute driver_attr_##_name = __ATTR_RO(_name)
extern int __must_check driver_create_file(struct device_driver *driver,
const struct driver_attribute *attr);
@ -313,6 +320,7 @@ int subsys_virtual_register(struct bus_type *subsys,
* @name: Name of the class.
* @owner: The module owner.
* @class_attrs: Default attributes of this class.
* @dev_groups: Default attributes of the devices that belong to the class.
* @dev_attrs: Default attributes of the devices belong to the class.
* @dev_bin_attrs: Default binary attributes of the devices belong to the class.
* @dev_kobj: The kobject that represents this class and links it into the hierarchy.
@ -342,7 +350,8 @@ struct class {
struct module *owner;
struct class_attribute *class_attrs;
struct device_attribute *dev_attrs;
struct device_attribute *dev_attrs; /* use dev_groups instead */
const struct attribute_group **dev_groups;
struct bin_attribute *dev_bin_attrs;
struct kobject *dev_kobj;
@ -414,8 +423,12 @@ struct class_attribute {
const struct class_attribute *attr);
};
#define CLASS_ATTR(_name, _mode, _show, _store) \
struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
#define CLASS_ATTR(_name, _mode, _show, _store) \
struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
#define CLASS_ATTR_RW(_name) \
struct class_attribute class_attr_##_name = __ATTR_RW(_name)
#define CLASS_ATTR_RO(_name) \
struct class_attribute class_attr_##_name = __ATTR_RO(_name)
extern int __must_check class_create_file(struct class *class,
const struct class_attribute *attr);
@ -423,7 +436,6 @@ extern void class_remove_file(struct class *class,
const struct class_attribute *attr);
/* Simple class attribute that is just a static string */
struct class_attribute_string {
struct class_attribute attr;
char *str;
@ -512,6 +524,10 @@ ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
#define DEVICE_ATTR(_name, _mode, _show, _store) \
struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
#define DEVICE_ATTR_RW(_name) \
struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
#define DEVICE_ATTR_RO(_name) \
struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
#define DEVICE_ULONG_ATTR(_name, _mode, _var) \
struct dev_ext_attribute dev_attr_##_name = \
{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
@ -924,6 +940,11 @@ extern __printf(5, 6)
struct device *device_create(struct class *cls, struct device *parent,
dev_t devt, void *drvdata,
const char *fmt, ...);
extern __printf(6, 7)
struct device *device_create_with_groups(struct class *cls,
struct device *parent, dev_t devt, void *drvdata,
const struct attribute_group **groups,
const char *fmt, ...);
extern void device_destroy(struct class *cls, dev_t devt);
/*

64
include/linux/sysfs.h
View File

@ -17,10 +17,12 @@
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/kobject_ns.h>
#include <linux/stat.h>
#include <linux/atomic.h>
struct kobject;
struct module;
struct bin_attribute;
enum kobj_ns_type;
struct attribute {
@ -59,26 +61,28 @@ struct attribute_group {
umode_t (*is_visible)(struct kobject *,
struct attribute *, int);
struct attribute **attrs;
struct bin_attribute **bin_attrs;
};
/**
* Use these macros to make defining attributes easier. See include/linux/device.h
* for examples..
*/
#define __ATTR(_name,_mode,_show,_store) { \
.attr = {.name = __stringify(_name), .mode = _mode }, \
.show = _show, \
.store = _store, \
#define __ATTR(_name,_mode,_show,_store) { \
.attr = {.name = __stringify(_name), .mode = _mode }, \
.show = _show, \
.store = _store, \
}
#define __ATTR_RO(_name) { \
.attr = { .name = __stringify(_name), .mode = 0444 }, \
.show = _name##_show, \
#define __ATTR_RO(_name) { \
.attr = { .name = __stringify(_name), .mode = S_IRUGO }, \
.show = _name##_show, \
}
#define __ATTR_RW(_name) __ATTR(_name, (S_IWUSR | S_IRUGO), \
_name##_show, _name##_store)
#define __ATTR_NULL { .attr = { .name = NULL } }
#ifdef CONFIG_DEBUG_LOCK_ALLOC
@ -92,6 +96,18 @@ struct attribute_group {
#define __ATTR_IGNORE_LOCKDEP __ATTR
#endif
#define __ATTRIBUTE_GROUPS(_name) \
static const struct attribute_group *_name##_groups[] = { \
&_name##_group, \
NULL, \
}
#define ATTRIBUTE_GROUPS(_name) \
static const struct attribute_group _name##_group = { \
.attrs = _name##_attrs, \
}; \
__ATTRIBUTE_GROUPS(_name)
#define attr_name(_attr) (_attr).attr.name
struct file;
@ -121,6 +137,36 @@ struct bin_attribute {
*/
#define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)
/* macros to create static binary attributes easier */
#define __BIN_ATTR(_name, _mode, _read, _write, _size) { \
.attr = { .name = __stringify(_name), .mode = _mode }, \
.read = _read, \
.write = _write, \
.size = _size, \
}
#define __BIN_ATTR_RO(_name, _size) { \
.attr = { .name = __stringify(_name), .mode = S_IRUGO }, \
.read = _name##_read, \
.size = _size, \
}
#define __BIN_ATTR_RW(_name, _size) __BIN_ATTR(_name, \
(S_IWUSR | S_IRUGO), _name##_read, \
_name##_write)
#define __BIN_ATTR_NULL __ATTR_NULL
#define BIN_ATTR(_name, _mode, _read, _write, _size) \
struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \
_write, _size)
#define BIN_ATTR_RO(_name, _size) \
struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size)
#define BIN_ATTR_RW(_name, _size) \
struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)
struct sysfs_ops {
ssize_t (*show)(struct kobject *, struct attribute *,char *);
ssize_t (*store)(struct kobject *,struct attribute *,const char *, size_t);

2
kernel/events/core.c
View File

@ -6234,8 +6234,6 @@ perf_event_mux_interval_ms_store(struct device *dev,
return count;
}
#define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store)
static struct device_attribute pmu_dev_attrs[] = {
__ATTR_RO(type),
__ATTR_RW(perf_event_mux_interval_ms),

2
mm/backing-dev.c
View File

@ -232,8 +232,6 @@ static ssize_t stable_pages_required_show(struct device *dev,
bdi_cap_stable_pages_required(bdi) ? 1 : 0);
}
#define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store)
static struct device_attribute bdi_dev_attrs[] = {
__ATTR_RW(read_ahead_kb),
__ATTR_RW(min_ratio),