use simple_read_from_buffer() in fs/

[linux-2.6-omap-h63xx.git] / fs / configfs / file.c

diff --git a/fs/configfs/file.c b/fs/configfs/file.c
index e6d5754a715ecde980dd50225495d3628c49e2d8..3527c7c6def898cb39d1118738b8d7a89475edc7 100644 (file)
--- a/fs/configfs/file.c
+++ b/fs/configfs/file.c
@@ -77,36 +77,6 @@ static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buf
        return ret;
 }
 
-
-/**
- *     flush_read_buffer - push buffer to userspace.
- *     @buffer:        data buffer for file.
- *     @userbuf:       user-passed buffer.
- *     @count:         number of bytes requested.
- *     @ppos:          file position.
- *
- *     Copy the buffer we filled in fill_read_buffer() to userspace.
- *     This is done at the reader's leisure, copying and advancing
- *     the amount they specify each time.
- *     This may be called continuously until the buffer is empty.
- */
-static int flush_read_buffer(struct configfs_buffer * buffer, char __user * buf,
-                            size_t count, loff_t * ppos)
-{
-       int error;
-
-       if (*ppos > buffer->count)
-               return 0;
-
-       if (count > (buffer->count - *ppos))
-               count = buffer->count - *ppos;
-
-       error = copy_to_user(buf,buffer->page + *ppos,count);
-       if (!error)
-               *ppos += count;
-       return error ? -EFAULT : count;
-}
-
 /**
  *     configfs_read_file - read an attribute.
  *     @file:  file pointer.
@@ -134,12 +104,13 @@ configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *pp
 
        down(&buffer->sem);
        if (buffer->needs_read_fill) {
-               if ((retval = fill_read_buffer(file->f_dentry,buffer)))
+               if ((retval = fill_read_buffer(file->f_path.dentry,buffer)))
                        goto out;
        }
        pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
                 __FUNCTION__, count, *ppos, buffer->page);
-       retval = flush_read_buffer(buffer,buf,count,ppos);
+       retval = simple_read_from_buffer(buf, count, ppos, buffer->page,
+                                        buffer->count);
 out:
        up(&buffer->sem);
        return retval;
@@ -162,14 +133,17 @@ fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size
        int error;
 
        if (!buffer->page)
-               buffer->page = (char *)get_zeroed_page(GFP_KERNEL);
+               buffer->page = (char *)__get_free_pages(GFP_KERNEL, 0);
        if (!buffer->page)
                return -ENOMEM;
 
-       if (count > PAGE_SIZE)
-               count = PAGE_SIZE;
+       if (count >= PAGE_SIZE)
+               count = PAGE_SIZE - 1;
        error = copy_from_user(buffer->page,buf,count);
        buffer->needs_read_fill = 1;
+       /* if buf is assumed to contain a string, terminate it by \0,
+        * so e.g. sscanf() can scan the string easily */
+       buffer->page[count] = 0;
        return error ? -EFAULT : count;
 }
 
@@ -222,7 +196,7 @@ configfs_write_file(struct file *file, const char __user *buf, size_t count, lof
        down(&buffer->sem);
        len = fill_write_buffer(buffer, buf, count);
        if (len > 0)
-               len = flush_write_buffer(file->f_dentry, buffer, count);
+               len = flush_write_buffer(file->f_path.dentry, buffer, count);
        if (len > 0)
                *ppos += len;
        up(&buffer->sem);
@@ -231,8 +205,8 @@ configfs_write_file(struct file *file, const char __user *buf, size_t count, lof
 
 static int check_perm(struct inode * inode, struct file * file)
 {
-       struct config_item *item = configfs_get_config_item(file->f_dentry->d_parent);
-       struct configfs_attribute * attr = to_attr(file->f_dentry);
+       struct config_item *item = configfs_get_config_item(file->f_path.dentry->d_parent);
+       struct configfs_attribute * attr = to_attr(file->f_path.dentry);
        struct configfs_buffer * buffer;
        struct configfs_item_operations * ops = NULL;
        int error = 0;
@@ -275,13 +249,14 @@ static int check_perm(struct inode * inode, struct file * file)
         * it in file->private_data for easy access.
         */
        buffer = kzalloc(sizeof(struct configfs_buffer),GFP_KERNEL);
-       if (buffer) {
-               init_MUTEX(&buffer->sem);
-               buffer->needs_read_fill = 1;
-               buffer->ops = ops;
-               file->private_data = buffer;
-       } else
+       if (!buffer) {
                error = -ENOMEM;
+               goto Enomem;
+       }
+       init_MUTEX(&buffer->sem);
+       buffer->needs_read_fill = 1;
+       buffer->ops = ops;
+       file->private_data = buffer;
        goto Done;
 
  Einval:
@@ -289,6 +264,7 @@ static int check_perm(struct inode * inode, struct file * file)
        goto Done;
  Eaccess:
        error = -EACCES;
+ Enomem:
        module_put(attr->ca_owner);
  Done:
        if (error && item)
@@ -303,8 +279,8 @@ static int configfs_open_file(struct inode * inode, struct file * filp)
 
 static int configfs_release(struct inode * inode, struct file * filp)
 {
-       struct config_item * item = to_item(filp->f_dentry->d_parent);
-       struct configfs_attribute * attr = to_attr(filp->f_dentry);
+       struct config_item * item = to_item(filp->f_path.dentry->d_parent);
+       struct configfs_attribute * attr = to_attr(filp->f_path.dentry);
        struct module * owner = attr->ca_owner;
        struct configfs_buffer * buffer = filp->private_data;