+static struct inode_operations sysfs_inode_operations ={
+ .setattr = sysfs_setattr,
+};
+
+int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
+{
+ struct inode * inode = dentry->d_inode;
+ struct sysfs_dirent * sd = dentry->d_fsdata;
+ struct iattr * sd_iattr;
+ unsigned int ia_valid = iattr->ia_valid;
+ int error;
+
+ if (!sd)
+ return -EINVAL;
+
+ sd_iattr = sd->s_iattr;
+
+ error = inode_change_ok(inode, iattr);
+ if (error)
+ return error;
+
+ error = inode_setattr(inode, iattr);
+ if (error)
+ return error;
+
+ if (!sd_iattr) {
+ /* setting attributes for the first time, allocate now */
+ sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
+ if (!sd_iattr)
+ return -ENOMEM;
+ /* assign default attributes */
+ sd_iattr->ia_mode = sd->s_mode;
+ sd_iattr->ia_uid = 0;
+ sd_iattr->ia_gid = 0;
+ sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
+ sd->s_iattr = sd_iattr;
+ }
+
+ /* attributes were changed atleast once in past */
+
+ if (ia_valid & ATTR_UID)
+ sd_iattr->ia_uid = iattr->ia_uid;
+ if (ia_valid & ATTR_GID)
+ sd_iattr->ia_gid = iattr->ia_gid;
+ if (ia_valid & ATTR_ATIME)
+ sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
+ inode->i_sb->s_time_gran);
+ if (ia_valid & ATTR_MTIME)
+ sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
+ inode->i_sb->s_time_gran);
+ if (ia_valid & ATTR_CTIME)
+ sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
+ inode->i_sb->s_time_gran);
+ if (ia_valid & ATTR_MODE) {
+ umode_t mode = iattr->ia_mode;
+
+ if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+ mode &= ~S_ISGID;
+ sd_iattr->ia_mode = sd->s_mode = mode;
+ }
+
+ return error;
+}
+
+static inline void set_default_inode_attr(struct inode * inode, mode_t mode)
+{
+ inode->i_mode = mode;
+ inode->i_uid = 0;
+ inode->i_gid = 0;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+}
+
+static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
+{
+ inode->i_mode = iattr->ia_mode;
+ inode->i_uid = iattr->ia_uid;
+ inode->i_gid = iattr->ia_gid;
+ inode->i_atime = iattr->ia_atime;
+ inode->i_mtime = iattr->ia_mtime;
+ inode->i_ctime = iattr->ia_ctime;
+}
+
+
+/*
+ * sysfs has a different i_mutex lock order behavior for i_mutex than other
+ * filesystems; sysfs i_mutex is called in many places with subsystem locks
+ * held. At the same time, many of the VFS locking rules do not apply to
+ * sysfs at all (cross directory rename for example). To untangle this mess
+ * (which gives false positives in lockdep), we're giving sysfs inodes their
+ * own class for i_mutex.
+ */
+static struct lock_class_key sysfs_inode_imutex_key;
+
+struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)