xref: /linux/fs/jffs2/writev.c (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
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 }
80