diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 548556ff250609677019712bbc066ef018bea107..efc97d9b78604d040ba12ae9b1e418a6f9818534 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -45,44 +45,15 @@ struct file_operations debugfs_file_operations = {
.open = default_open,
};
-#define simple_type(type, format, temptype, strtolfn) \
-static ssize_t read_file_##type(struct file *file, char __user *user_buf, \
- size_t count, loff_t *ppos) \
-{ \
- char buf[32]; \
- type *val = file->private_data; \
- \
- snprintf(buf, sizeof(buf), format "\n", *val); \
- return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));\
-} \
-static ssize_t write_file_##type(struct file *file, const char __user *user_buf,\
- size_t count, loff_t *ppos) \
-{ \
- char *endp; \
- char buf[32]; \
- int buf_size; \
- type *val = file->private_data; \
- temptype tmp; \
- \
- memset(buf, 0x00, sizeof(buf)); \
- buf_size = min(count, (sizeof(buf)-1)); \
- if (copy_from_user(buf, user_buf, buf_size)) \
- return -EFAULT; \
- \
- tmp = strtolfn(buf, &endp, 0); \
- if ((endp == buf) || ((type)tmp != tmp)) \
- return -EINVAL; \
- *val = tmp; \
- return count; \
-} \
-static struct file_operations fops_##type = { \
- .read = read_file_##type, \
- .write = write_file_##type, \
- .open = default_open, \
-};
-simple_type(u8, "%c", unsigned long, simple_strtoul);
-simple_type(u16, "%hi", unsigned long, simple_strtoul);
-simple_type(u32, "%i", unsigned long, simple_strtoul);
+static void debugfs_u8_set(void *data, u64 val)
+{
+ *(u8 *)data = val;
+}
+static u64 debugfs_u8_get(void *data)
+{
+ return *(u8 *)data;
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
/**
* debugfs_create_u8 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value.
@@ -116,6 +87,16 @@ struct dentry *debugfs_create_u8(const char *name, mode_t mode,
}
EXPORT_SYMBOL_GPL(debugfs_create_u8);
+static void debugfs_u16_set(void *data, u64 val)
+{
+ *(u16 *)data = val;
+}
+static u64 debugfs_u16_get(void *data)
+{
+ return *(u16 *)data;
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
+
/**
* debugfs_create_u16 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value.
*
@@ -148,6 +129,16 @@ struct dentry *debugfs_create_u16(const char *name, mode_t mode,
}
EXPORT_SYMBOL_GPL(debugfs_create_u16);
+static void debugfs_u32_set(void *data, u64 val)
+{
+ *(u32 *)data = val;
+}
+static u64 debugfs_u32_get(void *data)
+{
+ return *(u32 *)data;
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
+
/**
* debugfs_create_u32 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value.
*
diff --git a/fs/libfs.c b/fs/libfs.c
index f90b29595927e206c6fa4cee6e6ae796c509ce28..5025563e7379675b7df2834427aabb0800f4b740 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -519,6 +519,102 @@ int simple_transaction_release(struct inode *inode, struct file *file)
return 0;
}
+/* Simple attribute files */
+
+struct simple_attr {
+ u64 (*get)(void *);
+ void (*set)(void *, u64);
+ char get_buf[24]; /* enough to store a u64 and "\n\0" */
+ char set_buf[24];
+ void *data;
+ const char *fmt; /* format for read operation */
+ struct semaphore sem; /* protects access to these buffers */
+};
+
+/* simple_attr_open is called by an actual attribute open file operation
+ * to set the attribute specific access operations. */
+int simple_attr_open(struct inode *inode, struct file *file,
+ u64 (*get)(void *), void (*set)(void *, u64),
+ const char *fmt)
+{
+ struct simple_attr *attr;
+
+ attr = kmalloc(sizeof(*attr), GFP_KERNEL);
+ if (!attr)
+ return -ENOMEM;
+
+ attr->get = get;
+ attr->set = set;
+ attr->data = inode->u.generic_ip;
+ attr->fmt = fmt;
+ init_MUTEX(&attr->sem);
+
+ file->private_data = attr;
+
+ return nonseekable_open(inode, file);
+}
+
+int simple_attr_close(struct inode *inode, struct file *file)
+{
+ kfree(file->private_data);
+ return 0;
+}
+
+/* read from the buffer that is filled with the get function */
+ssize_t simple_attr_read(struct file *file, char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ struct simple_attr *attr;
+ size_t size;
+ ssize_t ret;
+
+ attr = file->private_data;
+
+ if (!attr->get)
+ return -EACCES;
+
+ down(&attr->sem);
+ if (*ppos) /* continued read */
+ size = strlen(attr->get_buf);
+ else /* first read */
+ size = scnprintf(attr->get_buf, sizeof(attr->get_buf),
+ attr->fmt,
+ (unsigned long long)attr->get(attr->data));
+
+ ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size);
+ up(&attr->sem);
+ return ret;
+}
+
+/* interpret the buffer as a number to call the set function with */
+ssize_t simple_attr_write(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ struct simple_attr *attr;
+ u64 val;
+ size_t size;
+ ssize_t ret;
+
+ attr = file->private_data;
+
+ if (!attr->set)
+ return -EACCES;
+
+ down(&attr->sem);
+ ret = -EFAULT;
+ size = min(sizeof(attr->set_buf) - 1, len);
+ if (copy_from_user(attr->set_buf, buf, size))
+ goto out;
+
+ ret = len; /* claim we got the whole input */
+ attr->set_buf[size] = '\0';
+ val = simple_strtol(attr->set_buf, NULL, 0);
+ attr->set(attr->data, val);
+out:
+ up(&attr->sem);
+ return ret;
+}
+
EXPORT_SYMBOL(dcache_dir_close);
EXPORT_SYMBOL(dcache_dir_lseek);
EXPORT_SYMBOL(dcache_dir_open);
@@ -547,3 +643,7 @@ EXPORT_SYMBOL(simple_read_from_buffer);
EXPORT_SYMBOL(simple_transaction_get);
EXPORT_SYMBOL(simple_transaction_read);
EXPORT_SYMBOL(simple_transaction_release);
+EXPORT_SYMBOL_GPL(simple_attr_open);
+EXPORT_SYMBOL_GPL(simple_attr_close);
+EXPORT_SYMBOL_GPL(simple_attr_read);
+EXPORT_SYMBOL_GPL(simple_attr_write);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0180102dace1ef28edcd1de1199cfe65f3ba8499..9b8b696d4f150a52b72dfb1addc673168ebd421b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1657,6 +1657,52 @@ static inline void simple_transaction_set(struct file *file, size_t n)
ar->size = n;
}
+/*
+ * simple attribute files
+ *
+ * These attributes behave similar to those in sysfs:
+ *
+ * Writing to an attribute immediately sets a value, an open file can be
+ * written to multiple times.
+ *
+ * Reading from an attribute creates a buffer from the value that might get
+ * read with multiple read calls. When the attribute has been read
+ * completely, no further read calls are possible until the file is opened
+ * again.
+ *
+ * All attributes contain a text representation of a numeric value
+ * that are accessed with the get() and set() functions.
+ */
+#define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \
+static int __fops ## _open(struct inode *inode, struct file *file) \
+{ \
+ __simple_attr_check_format(__fmt, 0ull); \
+ return simple_attr_open(inode, file, __get, __set, __fmt); \
+} \
+static struct file_operations __fops = { \
+ .owner = THIS_MODULE, \
+ .open = __fops ## _open, \
+ .release = simple_attr_close, \
+ .read = simple_attr_read, \
+ .write = simple_attr_write, \
+};
+
+static inline void __attribute__((format(printf, 1, 2)))
+__simple_attr_check_format(const char *fmt, ...)
+{
+ /* don't do anything, just let the compiler check the arguments; */
+}
+
+int simple_attr_open(struct inode *inode, struct file *file,
+ u64 (*get)(void *), void (*set)(void *, u64),
+ const char *fmt);
+int simple_attr_close(struct inode *inode, struct file *file);
+ssize_t simple_attr_read(struct file *file, char __user *buf,
+ size_t len, loff_t *ppos);
+ssize_t simple_attr_write(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos);
+
+
#ifdef CONFIG_SECURITY
static inline char *alloc_secdata(void)
{