You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
228 lines
6.7 KiB
228 lines
6.7 KiB
/*
|
|
* JFFS2 -- Journalling Flash File System, Version 2.
|
|
*
|
|
* Copyright © 2001-2007 Red Hat, Inc.
|
|
*
|
|
* Created by David Woodhouse <dwmw2@infradead.org>
|
|
*
|
|
* For licensing information, see the file 'LICENCE' in this directory.
|
|
*
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/crc32.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/mtd/mtd.h>
|
|
#include <linux/compiler.h>
|
|
#include "nodelist.h"
|
|
#include "compr.h"
|
|
|
|
int jffs2_read_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
|
|
struct jffs2_full_dnode *fd, unsigned char *buf,
|
|
int ofs, int len)
|
|
{
|
|
struct jffs2_raw_inode *ri;
|
|
size_t readlen;
|
|
uint32_t crc;
|
|
unsigned char *decomprbuf = NULL;
|
|
unsigned char *readbuf = NULL;
|
|
int ret = 0;
|
|
|
|
ri = jffs2_alloc_raw_inode();
|
|
if (!ri)
|
|
return -ENOMEM;
|
|
|
|
ret = jffs2_flash_read(c, ref_offset(fd->raw), sizeof(*ri), &readlen, (char *)ri);
|
|
if (ret) {
|
|
jffs2_free_raw_inode(ri);
|
|
pr_warn("Error reading node from 0x%08x: %d\n",
|
|
ref_offset(fd->raw), ret);
|
|
return ret;
|
|
}
|
|
if (readlen != sizeof(*ri)) {
|
|
jffs2_free_raw_inode(ri);
|
|
pr_warn("Short read from 0x%08x: wanted 0x%zx bytes, got 0x%zx\n",
|
|
ref_offset(fd->raw), sizeof(*ri), readlen);
|
|
return -EIO;
|
|
}
|
|
crc = crc32(0, ri, sizeof(*ri)-8);
|
|
|
|
jffs2_dbg(1, "Node read from %08x: node_crc %08x, calculated CRC %08x. dsize %x, csize %x, offset %x, buf %p\n",
|
|
ref_offset(fd->raw), je32_to_cpu(ri->node_crc),
|
|
crc, je32_to_cpu(ri->dsize), je32_to_cpu(ri->csize),
|
|
je32_to_cpu(ri->offset), buf);
|
|
if (crc != je32_to_cpu(ri->node_crc)) {
|
|
pr_warn("Node CRC %08x != calculated CRC %08x for node at %08x\n",
|
|
je32_to_cpu(ri->node_crc), crc, ref_offset(fd->raw));
|
|
ret = -EIO;
|
|
goto out_ri;
|
|
}
|
|
/* There was a bug where we wrote hole nodes out with csize/dsize
|
|
swapped. Deal with it */
|
|
if (ri->compr == JFFS2_COMPR_ZERO && !je32_to_cpu(ri->dsize) &&
|
|
je32_to_cpu(ri->csize)) {
|
|
ri->dsize = ri->csize;
|
|
ri->csize = cpu_to_je32(0);
|
|
}
|
|
|
|
D1(if(ofs + len > je32_to_cpu(ri->dsize)) {
|
|
pr_warn("jffs2_read_dnode() asked for %d bytes at %d from %d-byte node\n",
|
|
len, ofs, je32_to_cpu(ri->dsize));
|
|
ret = -EINVAL;
|
|
goto out_ri;
|
|
});
|
|
|
|
|
|
if (ri->compr == JFFS2_COMPR_ZERO) {
|
|
memset(buf, 0, len);
|
|
goto out_ri;
|
|
}
|
|
|
|
/* Cases:
|
|
Reading whole node and it's uncompressed - read directly to buffer provided, check CRC.
|
|
Reading whole node and it's compressed - read into comprbuf, check CRC and decompress to buffer provided
|
|
Reading partial node and it's uncompressed - read into readbuf, check CRC, and copy
|
|
Reading partial node and it's compressed - read into readbuf, check checksum, decompress to decomprbuf and copy
|
|
*/
|
|
if (ri->compr == JFFS2_COMPR_NONE && len == je32_to_cpu(ri->dsize)) {
|
|
readbuf = buf;
|
|
} else {
|
|
readbuf = kmalloc(je32_to_cpu(ri->csize), GFP_KERNEL);
|
|
if (!readbuf) {
|
|
ret = -ENOMEM;
|
|
goto out_ri;
|
|
}
|
|
}
|
|
if (ri->compr != JFFS2_COMPR_NONE) {
|
|
if (len < je32_to_cpu(ri->dsize)) {
|
|
decomprbuf = kmalloc(je32_to_cpu(ri->dsize), GFP_KERNEL);
|
|
if (!decomprbuf) {
|
|
ret = -ENOMEM;
|
|
goto out_readbuf;
|
|
}
|
|
} else {
|
|
decomprbuf = buf;
|
|
}
|
|
} else {
|
|
decomprbuf = readbuf;
|
|
}
|
|
|
|
jffs2_dbg(2, "Read %d bytes to %p\n", je32_to_cpu(ri->csize),
|
|
readbuf);
|
|
ret = jffs2_flash_read(c, (ref_offset(fd->raw)) + sizeof(*ri),
|
|
je32_to_cpu(ri->csize), &readlen, readbuf);
|
|
|
|
if (!ret && readlen != je32_to_cpu(ri->csize))
|
|
ret = -EIO;
|
|
if (ret)
|
|
goto out_decomprbuf;
|
|
|
|
crc = crc32(0, readbuf, je32_to_cpu(ri->csize));
|
|
if (crc != je32_to_cpu(ri->data_crc)) {
|
|
pr_warn("Data CRC %08x != calculated CRC %08x for node at %08x\n",
|
|
je32_to_cpu(ri->data_crc), crc, ref_offset(fd->raw));
|
|
ret = -EIO;
|
|
goto out_decomprbuf;
|
|
}
|
|
jffs2_dbg(2, "Data CRC matches calculated CRC %08x\n", crc);
|
|
if (ri->compr != JFFS2_COMPR_NONE) {
|
|
jffs2_dbg(2, "Decompress %d bytes from %p to %d bytes at %p\n",
|
|
je32_to_cpu(ri->csize), readbuf,
|
|
je32_to_cpu(ri->dsize), decomprbuf);
|
|
ret = jffs2_decompress(c, f, ri->compr | (ri->usercompr << 8), readbuf, decomprbuf, je32_to_cpu(ri->csize), je32_to_cpu(ri->dsize));
|
|
if (ret) {
|
|
pr_warn("Error: jffs2_decompress returned %d\n", ret);
|
|
goto out_decomprbuf;
|
|
}
|
|
}
|
|
|
|
if (len < je32_to_cpu(ri->dsize)) {
|
|
memcpy(buf, decomprbuf+ofs, len);
|
|
}
|
|
out_decomprbuf:
|
|
if(decomprbuf != buf && decomprbuf != readbuf)
|
|
kfree(decomprbuf);
|
|
out_readbuf:
|
|
if(readbuf != buf)
|
|
kfree(readbuf);
|
|
out_ri:
|
|
jffs2_free_raw_inode(ri);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int jffs2_read_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
|
|
unsigned char *buf, uint32_t offset, uint32_t len)
|
|
{
|
|
uint32_t end = offset + len;
|
|
struct jffs2_node_frag *frag;
|
|
int ret;
|
|
|
|
jffs2_dbg(1, "%s(): ino #%u, range 0x%08x-0x%08x\n",
|
|
__func__, f->inocache->ino, offset, offset + len);
|
|
|
|
frag = jffs2_lookup_node_frag(&f->fragtree, offset);
|
|
|
|
/* XXX FIXME: Where a single physical node actually shows up in two
|
|
frags, we read it twice. Don't do that. */
|
|
/* Now we're pointing at the first frag which overlaps our page
|
|
* (or perhaps is before it, if we've been asked to read off the
|
|
* end of the file). */
|
|
while(offset < end) {
|
|
jffs2_dbg(2, "%s(): offset %d, end %d\n",
|
|
__func__, offset, end);
|
|
if (unlikely(!frag || frag->ofs > offset ||
|
|
frag->ofs + frag->size <= offset)) {
|
|
uint32_t holesize = end - offset;
|
|
if (frag && frag->ofs > offset) {
|
|
jffs2_dbg(1, "Eep. Hole in ino #%u fraglist. frag->ofs = 0x%08x, offset = 0x%08x\n",
|
|
f->inocache->ino, frag->ofs, offset);
|
|
holesize = min(holesize, frag->ofs - offset);
|
|
}
|
|
jffs2_dbg(1, "Filling non-frag hole from %d-%d\n",
|
|
offset, offset + holesize);
|
|
memset(buf, 0, holesize);
|
|
buf += holesize;
|
|
offset += holesize;
|
|
continue;
|
|
} else if (unlikely(!frag->node)) {
|
|
uint32_t holeend = min(end, frag->ofs + frag->size);
|
|
jffs2_dbg(1, "Filling frag hole from %d-%d (frag 0x%x 0x%x)\n",
|
|
offset, holeend, frag->ofs,
|
|
frag->ofs + frag->size);
|
|
memset(buf, 0, holeend - offset);
|
|
buf += holeend - offset;
|
|
offset = holeend;
|
|
frag = frag_next(frag);
|
|
continue;
|
|
} else {
|
|
uint32_t readlen;
|
|
uint32_t fragofs; /* offset within the frag to start reading */
|
|
|
|
fragofs = offset - frag->ofs;
|
|
readlen = min(frag->size - fragofs, end - offset);
|
|
jffs2_dbg(1, "Reading %d-%d from node at 0x%08x (%d)\n",
|
|
frag->ofs+fragofs,
|
|
frag->ofs + fragofs+readlen,
|
|
ref_offset(frag->node->raw),
|
|
ref_flags(frag->node->raw));
|
|
ret = jffs2_read_dnode(c, f, frag->node, buf, fragofs + frag->ofs - frag->node->ofs, readlen);
|
|
jffs2_dbg(2, "node read done\n");
|
|
if (ret) {
|
|
jffs2_dbg(1, "%s(): error %d\n",
|
|
__func__, ret);
|
|
memset(buf, 0, readlen);
|
|
return ret;
|
|
}
|
|
buf += readlen;
|
|
offset += readlen;
|
|
frag = frag_next(frag);
|
|
jffs2_dbg(2, "node read was OK. Looping\n");
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|