xref: /openbmc/linux/fs/jffs2/writev.c (revision eda95cbf)
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,
30 				vecs[i].iov_base);
31 		totlen += thislen;
32 		if (ret || thislen != vecs[i].iov_len)
33 			break;
34 		to += vecs[i].iov_len;
35 	}
36 	if (retlen)
37 		*retlen = totlen;
38 	return ret;
39 }
40 
41 int jffs2_flash_direct_writev(struct jffs2_sb_info *c, const struct kvec *vecs,
42 			      unsigned long count, loff_t to, size_t *retlen)
43 {
44 	if (!jffs2_is_writebuffered(c)) {
45 		if (jffs2_sum_active()) {
46 			int res;
47 			res = jffs2_sum_add_kvec(c, vecs, count, (uint32_t) to);
48 			if (res) {
49 				return res;
50 			}
51 		}
52 	}
53 
54 	if (c->mtd->writev)
55 		return c->mtd->writev(c->mtd, vecs, count, to, retlen);
56 	else {
57 		return mtd_fake_writev(c->mtd, vecs, count, to, retlen);
58 	}
59 }
60 
61 int jffs2_flash_direct_write(struct jffs2_sb_info *c, loff_t ofs, size_t len,
62 			size_t *retlen, const u_char *buf)
63 {
64 	int ret;
65 	ret = mtd_write(c->mtd, ofs, len, retlen, buf);
66 
67 	if (jffs2_sum_active()) {
68 		struct kvec vecs[1];
69 		int res;
70 
71 		vecs[0].iov_base = (unsigned char *) buf;
72 		vecs[0].iov_len = len;
73 
74 		res = jffs2_sum_add_kvec(c, vecs, 1, (uint32_t) ofs);
75 		if (res) {
76 			return res;
77 		}
78 	}
79 	return ret;
80 }
81