[RFC 07/11] split out libfs/file.c from libfs.c

From: Arnd Bergmann
Date: Mon Feb 18 2008 - 23:15:23 EST


Consolidate all file manipulation code in libfs in a single
source file.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Index: linux-2.6/fs/libfs.c
===================================================================
--- linux-2.6.orig/fs/libfs.c
+++ linux-2.6/fs/libfs.c
@@ -421,165 +421,6 @@ ssize_t simple_read_from_buffer(void __u
}

/*
- * Transaction based IO.
- * The file expects a single write which triggers the transaction, and then
- * possibly a read which collects the result - which is stored in a
- * file-local buffer.
- */
-char *simple_transaction_get(struct file *file, const char __user *buf, size_t size)
-{
- struct simple_transaction_argresp *ar;
- static DEFINE_SPINLOCK(simple_transaction_lock);
-
- if (size > SIMPLE_TRANSACTION_LIMIT - 1)
- return ERR_PTR(-EFBIG);
-
- ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL);
- if (!ar)
- return ERR_PTR(-ENOMEM);
-
- spin_lock(&simple_transaction_lock);
-
- /* only one write allowed per open */
- if (file->private_data) {
- spin_unlock(&simple_transaction_lock);
- free_page((unsigned long)ar);
- return ERR_PTR(-EBUSY);
- }
-
- file->private_data = ar;
-
- spin_unlock(&simple_transaction_lock);
-
- if (copy_from_user(ar->data, buf, size))
- return ERR_PTR(-EFAULT);
-
- return ar->data;
-}
-
-ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
-{
- struct simple_transaction_argresp *ar = file->private_data;
-
- if (!ar)
- return 0;
- return simple_read_from_buffer(buf, size, pos, ar->data, ar->size);
-}
-
-int simple_transaction_release(struct inode *inode, struct file *file)
-{
- free_page((unsigned long)file->private_data);
- return 0;
-}
-
-/* Simple attribute files */
-
-struct simple_attr {
- int (*get)(void *, u64 *);
- int (*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 mutex mutex; /* 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,
- int (*get)(void *, u64 *), int (*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->i_private;
- attr->fmt = fmt;
- mutex_init(&attr->mutex);
-
- file->private_data = attr;
-
- return nonseekable_open(inode, file);
-}
-
-int simple_attr_release(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;
-
- ret = mutex_lock_interruptible(&attr->mutex);
- if (ret)
- return ret;
-
- if (*ppos) { /* continued read */
- size = strlen(attr->get_buf);
- } else { /* first read */
- u64 val;
- ret = attr->get(attr->data, &val);
- if (ret)
- goto out;
-
- size = scnprintf(attr->get_buf, sizeof(attr->get_buf),
- attr->fmt, (unsigned long long)val);
- }
-
- ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size);
-out:
- mutex_unlock(&attr->mutex);
- 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;
-
- ret = mutex_lock_interruptible(&attr->mutex);
- if (ret)
- return ret;
-
- 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:
- mutex_unlock(&attr->mutex);
- return ret;
-}
-
-/*
* This is what d_alloc_anon should have been. Once the exportfs
* argument transition has been finished I will update d_alloc_anon
* to this prototype and this wrapper will go away. --hch
@@ -689,10 +530,3 @@ EXPORT_SYMBOL(simple_statfs);
EXPORT_SYMBOL(simple_sync_file);
EXPORT_SYMBOL(simple_unlink);
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_release);
-EXPORT_SYMBOL_GPL(simple_attr_read);
-EXPORT_SYMBOL_GPL(simple_attr_write);
Index: linux-2.6/fs/libfs/file.c
===================================================================
--- linux-2.6.orig/fs/libfs/file.c
+++ linux-2.6/fs/libfs/file.c
@@ -9,6 +9,172 @@

#include <asm/uaccess.h>

+/*
+ * Transaction based IO.
+ * The file expects a single write which triggers the transaction, and then
+ * possibly a read which collects the result - which is stored in a
+ * file-local buffer.
+ */
+char *simple_transaction_get(struct file *file, const char __user *buf, size_t size)
+{
+ struct simple_transaction_argresp *ar;
+ static DEFINE_SPINLOCK(simple_transaction_lock);
+
+ if (size > SIMPLE_TRANSACTION_LIMIT - 1)
+ return ERR_PTR(-EFBIG);
+
+ ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL);
+ if (!ar)
+ return ERR_PTR(-ENOMEM);
+
+ spin_lock(&simple_transaction_lock);
+
+ /* only one write allowed per open */
+ if (file->private_data) {
+ spin_unlock(&simple_transaction_lock);
+ free_page((unsigned long)ar);
+ return ERR_PTR(-EBUSY);
+ }
+
+ file->private_data = ar;
+
+ spin_unlock(&simple_transaction_lock);
+
+ if (copy_from_user(ar->data, buf, size))
+ return ERR_PTR(-EFAULT);
+
+ return ar->data;
+}
+EXPORT_SYMBOL(simple_transaction_get);
+
+ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
+{
+ struct simple_transaction_argresp *ar = file->private_data;
+
+ if (!ar)
+ return 0;
+ return simple_read_from_buffer(buf, size, pos, ar->data, ar->size);
+}
+EXPORT_SYMBOL(simple_transaction_read);
+
+int simple_transaction_release(struct inode *inode, struct file *file)
+{
+ free_page((unsigned long)file->private_data);
+ return 0;
+}
+EXPORT_SYMBOL(simple_transaction_release);
+
+/* Simple attribute files */
+
+struct simple_attr {
+ int (*get)(void *, u64 *);
+ int (*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 mutex mutex; /* 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,
+ int (*get)(void *, u64 *), int (*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->i_private;
+ attr->fmt = fmt;
+ mutex_init(&attr->mutex);
+
+ file->private_data = attr;
+
+ return nonseekable_open(inode, file);
+}
+EXPORT_SYMBOL_GPL(simple_attr_open);
+
+int simple_attr_release(struct inode *inode, struct file *file)
+{
+ kfree(file->private_data);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(simple_attr_release);
+
+/* 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;
+
+ ret = mutex_lock_interruptible(&attr->mutex);
+ if (ret)
+ return ret;
+
+ if (*ppos) { /* continued read */
+ size = strlen(attr->get_buf);
+ } else { /* first read */
+ u64 val;
+ ret = attr->get(attr->data, &val);
+ if (ret)
+ goto out;
+
+ size = scnprintf(attr->get_buf, sizeof(attr->get_buf),
+ attr->fmt, (unsigned long long)val);
+ }
+
+ ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size);
+out:
+ mutex_unlock(&attr->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(simple_attr_read);
+
+/* 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;
+
+ ret = mutex_lock_interruptible(&attr->mutex);
+ if (ret)
+ return ret;
+
+ 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:
+ mutex_unlock(&attr->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(simple_attr_write);
+
/* commonly used attribute file operations */
static int simple_u8_set(void *data, u64 val)
{

--

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