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 "mtd_dev.h"
14 #include "nodelist.h"
15
jffs2_flash_direct_writev(struct jffs2_sb_info * c,const struct kvec * vecs,unsigned long count,loff_t to,size_t * retlen)16 int jffs2_flash_direct_writev(struct jffs2_sb_info *c, const struct kvec *vecs,
17 unsigned long count, loff_t to, size_t *retlen)
18 {
19 unsigned long i;
20 size_t totlen = 0, thislen;
21 int ret = 0;
22
23 for (i = 0; i < count; i++) {
24 // writes need to be aligned but the data we're passed may not be
25 // Observation suggests most unaligned writes are small, so we
26 // optimize for that case.
27
28 if (((vecs[i].iov_len & (sizeof(int) - 1))) ||
29 (((unsigned long) vecs[i].iov_base & (sizeof(unsigned long) - 1)))) {
30 // are there iov's after this one? Or is it so much we'd need
31 // to do multiple writes anyway?
32 if ((i + 1) < count || vecs[i].iov_len > 256) {
33 // cop out and malloc
34 unsigned long j;
35 size_t sizetomalloc = 0, totvecsize = 0;
36 char *cbuf, *cbufptr;
37
38 for (j = i; j < count; j++)
39 totvecsize += vecs[j].iov_len;
40
41 // pad up in case unaligned
42 sizetomalloc = totvecsize + sizeof(int) - 1;
43 sizetomalloc &= ~(sizeof(int) - 1);
44 cbuf = (char *) malloc(sizetomalloc);
45 // malloc returns aligned memory
46 if (!cbuf) {
47 ret = -ENOMEM;
48 goto writev_out;
49 }
50 cbufptr = cbuf;
51 for (j = i; j < count; j++) {
52 (void)memcpy_s(cbufptr, vecs[j].iov_len, vecs[j].iov_base, vecs[j].iov_len);
53 cbufptr += vecs[j].iov_len;
54 }
55 ret = jffs2_flash_write(c, to, sizetomalloc, &thislen,
56 (unsigned char *) cbuf);
57 if (thislen > totvecsize) // in case it was aligned up
58 thislen = totvecsize;
59 totlen += thislen;
60 free(cbuf);
61 goto writev_out;
62 } else {
63 // otherwise optimize for the common case
64 int buf[256/sizeof(int)]; // int, so int aligned
65 size_t lentowrite;
66
67 lentowrite = vecs[i].iov_len;
68 // pad up in case its unaligned
69 lentowrite += sizeof(int) - 1;
70 lentowrite &= ~(sizeof(int) - 1);
71 ret = memcpy_s(buf, sizeof(buf), vecs[i].iov_base, vecs[i].iov_len);
72 if (ret != EOK)
73 goto writev_out;
74
75 ret = jffs2_flash_write(c, to, lentowrite, &thislen,
76 (unsigned char *) &buf[0]);
77 if (thislen > vecs[i].iov_len)
78 thislen = vecs[i].iov_len;
79 }
80 } else {
81 ret = jffs2_flash_write(c, to, vecs[i].iov_len, &thislen,
82 vecs[i].iov_base);
83 }
84 totlen += thislen;
85 if (ret || thislen != vecs[i].iov_len) break;
86 to += vecs[i].iov_len;
87 }
88
89 writev_out:
90 if (retlen) *retlen = totlen;
91
92 return ret;
93 }
94
jffs2_flash_direct_write(struct jffs2_sb_info * c,loff_t ofs,size_t len,size_t * retlen,const u_char * buf)95 int jffs2_flash_direct_write(struct jffs2_sb_info *c, loff_t ofs, size_t len,
96 size_t *retlen, const u_char *buf)
97 {
98 int ret;
99 ret = c->mtd->write(c->mtd, ofs, len, (char *)buf);
100 if (ret >= 0) {
101 *retlen = ret;
102 return 0;
103 }
104 *retlen = 0;
105 return ret;
106 }
107