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 */
  19 static 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
  40 int 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
  60 int 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 }