fs/jffs2/writev.c

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright (C) 2001, 2002 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  * $Id: writev.c,v 1.8 2005/09/09 15:11:58 havasi Exp $
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/mtd/mtd.h>
  16 #include "nodelist.h"
  17
  18 /* This ought to be in core MTD code. All registered MTD devices
  19    without writev should have this put in place. Bug the MTD
  20    maintainer */
  21 static inline int mtd_fake_writev(struct mtd_info *mtd, const struct kvec *vecs,
  22                                   unsigned long count, loff_t to, size_t *retlen)
  23 {
  24         unsigned long i;
  25         size_t totlen = 0, thislen;
  26         int ret = 0;
  27
  28         for (i=0; i<count; i++) {
  29                 if (!vecs[i].iov_len)
  30                         continue;
  31                 ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
  32                 totlen += thislen;
  33                 if (ret || thislen != vecs[i].iov_len)
  34                         break;
  35                 to += vecs[i].iov_len;
  36         }
  37         if (retlen)
  38                 *retlen = totlen;
  39         return ret;
  40 }
  41
  42 int jffs2_flash_direct_writev(struct jffs2_sb_info *c, const struct kvec *vecs,
  43                               unsigned long count, loff_t to, size_t *retlen)
  44 {
  45         if (!jffs2_is_writebuffered(c)) {
  46                 if (jffs2_sum_active()) {
  47                         int res;
  48                         res = jffs2_sum_add_kvec(c, vecs, count, (uint32_t) to);
  49                         if (res) {
  50                                 return res;
  51                         }
  52                 }
  53         }
  54
  55         if (c->mtd->writev)
  56                 return c->mtd->writev(c->mtd, vecs, count, to, retlen);
  57         else {
  58                 return mtd_fake_writev(c->mtd, vecs, count, to, retlen);
  59         }
  60 }
  61
  62 int jffs2_flash_direct_write(struct jffs2_sb_info *c, loff_t ofs, size_t len,
  63                         size_t *retlen, const u_char *buf)
  64 {
  65         int ret;
  66         ret = c->mtd->write(c->mtd, ofs, len, retlen, buf);
  67
  68         if (jffs2_sum_active()) {
  69                 struct kvec vecs[1];
  70                 int res;
  71
  72                 vecs[0].iov_base = (unsigned char *) buf;
  73                 vecs[0].iov_len = len;
  74
  75                 res = jffs2_sum_add_kvec(c, vecs, 1, (uint32_t) ofs);
  76                 if (res) {
  77                         return res;
  78                 }
  79         }
  80         return ret;
  81 }