diff options
Diffstat (limited to 'Documentation/filesystems/sysfs.rst')
| -rw-r--r-- | Documentation/filesystems/sysfs.rst | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/Documentation/filesystems/sysfs.rst b/Documentation/filesystems/sysfs.rst index ab0f7795792b..004d490179f3 100644 --- a/Documentation/filesystems/sysfs.rst +++ b/Documentation/filesystems/sysfs.rst @@ -172,14 +172,13 @@ calls the associated methods. To illustrate:: - #define to_dev(obj) container_of(obj, struct device, kobj) #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) { struct device_attribute *dev_attr = to_dev_attr(attr); - struct device *dev = to_dev(kobj); + struct device *dev = kobj_to_dev(kobj); ssize_t ret = -EIO; if (dev_attr->show) @@ -242,12 +241,10 @@ Other notes: is 4096. - show() methods should return the number of bytes printed into the - buffer. This is the return value of scnprintf(). + buffer. -- show() must not use snprintf() when formatting the value to be - returned to user space. If you can guarantee that an overflow - will never happen you can use sprintf() otherwise you must use - scnprintf(). +- show() should only use sysfs_emit() or sysfs_emit_at() when formatting + the value to be returned to user space. - store() should return the number of bytes used from the buffer. If the entire buffer has been used, just return the count argument. |