LXR linux/fs/jffs2/writev.c

   1/*
   2 * JFFS2 -- Journalling Flash File System, Version 2.
   3 *
   4 * Copyright © 2001-2007 Red Hat, Inc.
   5 *
   6 * Created by David Woodhouse <dwmw2@infradead.org>
   7 *
   8 * For licensing information, see the file 'LICENCE' in this directory.
   9 *
  10 */
  11
  12#include <linux/kernel.h>
  13#include <linux/mtd/mtd.h>
  14#include "nodelist.h"
  15
  16/* This ought to be in core MTD code. All registered MTD devices
  17   without writev should have this put in place. Bug the MTD
  18   maintainer */
  19static inline int mtd_fake_writev(struct mtd_info *mtd, const struct kvec *vecs,
  20                                  unsigned long count, loff_t to, size_t *retlen)
  21{
  22        unsigned long i;
  23        size_t totlen = 0, thislen;
  24        int ret = 0;
  25
  26        for (i=0; i<count; i++) {
  27                if (!vecs[i].iov_len)
  28                        continue;
  29                ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
  30                totlen += thislen;
  31                if (ret || thislen != vecs[i].iov_len)
  32                        break;
  33                to += vecs[i].iov_len;
  34        }
  35        if (retlen)
  36                *retlen = totlen;
  37        return ret;
  38}
  39
  40int jffs2_flash_direct_writev(struct jffs2_sb_info *c, const struct kvec *vecs,
  41                              unsigned long count, loff_t to, size_t *retlen)
  42{
  43        if (!jffs2_is_writebuffered(c)) {
  44                if (jffs2_sum_active()) {
  45                        int res;
  46                        res = jffs2_sum_add_kvec(c, vecs, count, (uint32_t) to);
  47                        if (res) {
  48                                return res;
  49                        }
  50                }
  51        }
  52
  53        if (c->mtd->writev)
  54                return c->mtd->writev(c->mtd, vecs, count, to, retlen);
  55        else {
  56                return mtd_fake_writev(c->mtd, vecs, count, to, retlen);
  57        }
  58}
  59
  60int jffs2_flash_direct_write(struct jffs2_sb_info *c, loff_t ofs, size_t len,
  61                        size_t *retlen, const u_char *buf)
  62{
  63        int ret;
  64        ret = c->mtd->write(c->mtd, ofs, len, retlen, buf);
  65
  66        if (jffs2_sum_active()) {
  67                struct kvec vecs[1];
  68                int res;
  69
  70                vecs[0].iov_base = (unsigned char *) buf;
  71                vecs[0].iov_len = len;
  72
  73                res = jffs2_sum_add_kvec(c, vecs, 1, (uint32_t) ofs);
  74                if (res) {
  75                        return res;
  76                }
  77        }
  78        return ret;
  79}
  80