linux-imx

/* handling of writes to regular files and writing back to the server

 *

 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.

 * Written by David Howells (dhowells@redhat.com)

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */

​

#include <linux/backing-dev.h>

#include <linux/slab.h>

#include <linux/fs.h>

#include <linux/pagemap.h>

#include <linux/writeback.h>

#include <linux/pagevec.h>

#include "internal.h"

​

/*

 * mark a page as having been made dirty and thus needing writeback

 */

int afs_set_page_dirty(struct page *page)

{

    _enter("");

    return __set_page_dirty_nobuffers(page);

}

​

/*

 * partly or wholly fill a page that's under preparation for writing

 */

static int afs_fill_page(struct afs_vnode *vnode, struct key *key,

             loff_t pos, unsigned int len, struct page *page)

{

    struct afs_read *req;

    size_t p;

    void *data;

    int ret;

​

    _enter(",,%llu", (unsigned long long)pos);

​

    if (pos >= vnode->vfs_inode.i_size) {

        p = pos & ~PAGE_MASK;

        ASSERTCMP(p + len, <=, PAGE_SIZE);

        data = kmap(page);

        memset(data + p, 0, len);

        kunmap(page);

        return 0;

    }

​

    req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),

              GFP_KERNEL);

    if (!req)

        return -ENOMEM;

​

    refcount_set(&req->usage, 1);

    req->pos = pos;

    req->len = len;

    req->nr_pages = 1;

    req->pages = req->array;

    req->pages[0] = page;

    get_page(page);

​