Root/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

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