extractedLnx/linux-2.6.21/fs/jffs2/scan.c_jffs2_scan_eraseblock.c
static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
struct jffs2_unknown_node *node;
struct jffs2_unknown_node crcnode;
uint32_t ofs, prevofs;
uint32_t hdr_crc, buf_ofs, buf_len;
int err;
int noise = 0;
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
int cleanmarkerfound = 0;
#endif
ofs = jeb->offset;
prevofs = jeb->offset - 1;
D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
if (jffs2_cleanmarker_oob(c)) {
int ret;
if (c->mtd->block_isbad(c->mtd, jeb->offset))
return BLK_STATE_BADBLOCK;
ret = jffs2_check_nand_cleanmarker(c, jeb);
D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
/* Even if it's not found, we still scan to see
if the block is empty. We use this information
to decide whether to erase it or not. */
switch (ret) {
case 0: cleanmarkerfound = 1; break;
case 1: break;
default: return ret;
}
}
#endif
if (jffs2_sum_active()) {
struct jffs2_sum_marker *sm;
void *sumptr = NULL;
uint32_t sumlen;
if (!buf_size) {
/* XIP case. Just look, point at the summary if it's there */
sm = (void *)buf + c->sector_size - sizeof(*sm);
if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
sumptr = buf + je32_to_cpu(sm->offset);
sumlen = c->sector_size - je32_to_cpu(sm->offset);
}
} else {
/* If NAND flash, read a whole page of it. Else just the end */
if (c->wbuf_pagesize)
buf_len = c->wbuf_pagesize;
else
buf_len = sizeof(*sm);
/* Read as much as we want into the _end_ of the preallocated buffer */
err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
jeb->offset + c->sector_size - buf_len,
buf_len);
if (err)
return err;
sm = (void *)buf + buf_size - sizeof(*sm);
if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
sumlen = c->sector_size - je32_to_cpu(sm->offset);
sumptr = buf + buf_size - sumlen;
/* Now, make sure the summary itself is available */
if (sumlen > buf_size) {
/* Need to kmalloc for this. */
sumptr = kmalloc(sumlen, GFP_KERNEL);
if (!sumptr)
return -ENOMEM;
memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
}
if (buf_len < sumlen) {
/* Need to read more so that the entire summary node is present */
err = jffs2_fill_scan_buf(c, sumptr,
jeb->offset + c->sector_size - sumlen,
sumlen - buf_len);
if (err)
return err;
}
}
}
if (sumptr) {
err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
if (buf_size && sumlen > buf_size)
kfree(sumptr);
/* If it returns with a real error, bail.
If it returns positive, that's a block classification
(i.e. BLK_STATE_xxx) so return that too.
If it returns zero, fall through to full scan. */
if (err)
return err;
}
}
buf_ofs = jeb->offset;
if (!buf_size) {
/* This is the XIP case -- we're reading _directly_ from the flash chip */
buf_len = c->sector_size;
} else {
buf_len = EMPTY_SCAN_SIZE(c->sector_size);
err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
if (err)
return err;
}
/* We temporarily use 'ofs' as a pointer into the buffer/jeb */
ofs = 0;
/* Scan only 4KiB of 0xFF before declaring it's empty */
while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
ofs += 4;
if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
if (jffs2_cleanmarker_oob(c)) {
/* scan oob, take care of cleanmarker */
int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
switch (ret) {
case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
case 1: return BLK_STATE_ALLDIRTY;
default: return ret;
}
}
#endif
D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
if (c->cleanmarker_size == 0)
return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
else
return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
}
if (ofs) {
D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
jeb->offset + ofs));
if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
return err;
if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
return err;
}
/* Now ofs is a complete physical flash offset as it always was... */
ofs += jeb->offset;
noise = 10;
dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
scan_more:
while(ofs < jeb->offset + c->sector_size) {
jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
/* Make sure there are node refs available for use */
err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
if (err)
return err;
cond_resched();
if (ofs & 3) {
printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
ofs = PAD(ofs);
continue;
}
if (ofs == prevofs) {
printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
return err;
ofs += 4;
continue;
}
prevofs = ofs;
if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
D1(printk(KERN_DEBUG "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", sizeof(struct jffs2_unknown_node),
jeb->offset, c->sector_size, ofs, sizeof(*node)));
if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
return err;
break;
}
if (buf_ofs + buf_len < ofs + sizeof(*node)) {
buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
sizeof(struct jffs2_unknown_node), buf_len, ofs));
err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
if (err)
return err;
buf_ofs = ofs;
}
node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
uint32_t inbuf_ofs;
uint32_t empty_start;
empty_start = ofs;
ofs += 4;
D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
more_empty:
inbuf_ofs = ofs - buf_ofs;
while (inbuf_ofs < buf_len) {
if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) {
printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
empty_start, ofs);
if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
return err;
goto scan_more;
}
inbuf_ofs+=4;
ofs += 4;
}
/* Ran off end. */
D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
/* If we're only checking the beginning of a block with a cleanmarker,
bail now */
if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
return BLK_STATE_CLEANMARKER;
}
/* See how much more there is to read in this eraseblock... */
buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
if (!buf_len) {
/* No more to read. Break out of main loop without marking
this range of empty space as dirty (because it's not) */
D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
empty_start));
break;
}
D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
if (err)
return err;
buf_ofs = ofs;
goto more_empty;
}
if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
return err;
ofs += 4;
continue;
}
if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
return err;
ofs += 4;
continue;
}
if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
return err;
ofs += 4;
continue;
}
if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
/* OK. We're out of possibilities. Whinge and move on */
noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
JFFS2_MAGIC_BITMASK, ofs,
je16_to_cpu(node->magic));
if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
return err;
ofs += 4;
continue;
}
/* We seem to have a node of sorts. Check the CRC */
crcnode.magic = node->magic;
crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
crcnode.totlen = node->totlen;
hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
noisy_printk(&noise, "jffs2_scan_eraseblock(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
ofs, je16_to_cpu(node->magic),
je16_to_cpu(node->nodetype),
je32_to_cpu(node->totlen),
je32_to_cpu(node->hdr_crc),
hdr_crc);
if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
return err;
ofs += 4;
continue;
}
/* Due to poor choice of crc32 seed, an all-zero node will have a correct CRC */
if (!je32_to_cpu(node->hdr_crc) && !je16_to_cpu(node->nodetype) &&
!je16_to_cpu(node->magic) && !je32_to_cpu(node->totlen)) {
noisy_printk(&noise, "jffs2_scan_eraseblock(): All zero node header at 0x%08x.\n", ofs);
if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
return err;
ofs += 4;
continue;
}
if (ofs + je32_to_cpu(node->totlen) >
jeb->offset + c->sector_size) {
/* Eep. Node goes over the end of the erase block. */
printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
ofs, je32_to_cpu(node->totlen));
printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
return err;
ofs += 4;
continue;
}
if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
/* Wheee. This is an obsoleted node */
D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
return err;
ofs += PAD(je32_to_cpu(node->totlen));
continue;
}
switch(je16_to_cpu(node->nodetype)) {
case JFFS2_NODETYPE_INODE:
if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
sizeof(struct jffs2_raw_inode), buf_len, ofs));
err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
if (err)
return err;
buf_ofs = ofs;
node = (void *)buf;
}
err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
if (err) return err;
ofs += PAD(je32_to_cpu(node->totlen));
break;
case JFFS2_NODETYPE_DIRENT:
if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
je32_to_cpu(node->totlen), buf_len, ofs));
err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
if (err)
return err;
buf_ofs = ofs;
node = (void *)buf;
}
err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
if (err) return err;
ofs += PAD(je32_to_cpu(node->totlen));
break;
#ifdef CONFIG_JFFS2_FS_XATTR
case JFFS2_NODETYPE_XATTR:
if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
" left to end of buf. Reading 0x%x at 0x%08x\n",
je32_to_cpu(node->totlen), buf_len, ofs));
err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
if (err)
return err;
buf_ofs = ofs;
node = (void *)buf;
}
err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
if (err)
return err;
ofs += PAD(je32_to_cpu(node->totlen));
break;
case JFFS2_NODETYPE_XREF:
if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
" left to end of buf. Reading 0x%x at 0x%08x\n",
je32_to_cpu(node->totlen), buf_len, ofs));
err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
if (err)
return err;
buf_ofs = ofs;
node = (void *)buf;
}
err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
if (err)
return err;
ofs += PAD(je32_to_cpu(node->totlen));
break;
#endif /* CONFIG_JFFS2_FS_XATTR */
case JFFS2_NODETYPE_CLEANMARKER:
D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
return err;
ofs += PAD(sizeof(struct jffs2_unknown_node));
} else if (jeb->first_node) {
printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
return err;
ofs += PAD(sizeof(struct jffs2_unknown_node));
} else {
jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
ofs += PAD(c->cleanmarker_size);
}
break;
case JFFS2_NODETYPE_PADDING:
if (jffs2_sum_active())
jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
return err;
ofs += PAD(je32_to_cpu(node->totlen));
break;
default:
switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
case JFFS2_FEATURE_ROCOMPAT:
printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
c->flags |= JFFS2_SB_FLAG_RO;
if (!(jffs2_is_readonly(c)))
return -EROFS;
if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
return err;
ofs += PAD(je32_to_cpu(node->totlen));
break;
case JFFS2_FEATURE_INCOMPAT:
printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
return -EINVAL;
case JFFS2_FEATURE_RWCOMPAT_DELETE:
D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
return err;
ofs += PAD(je32_to_cpu(node->totlen));
break;
case JFFS2_FEATURE_RWCOMPAT_COPY: {
D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
/* We can't summarise nodes we don't grok */
jffs2_sum_disable_collecting(s);
ofs += PAD(je32_to_cpu(node->totlen));
break;
}
}
}
}
if (jffs2_sum_active()) {
if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
dbg_summary("There is not enough space for "
"summary information, disabling for this jeb!\n");
jffs2_sum_disable_collecting(s);
}
}
D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
/* mark_node_obsolete can add to wasted !! */
if (jeb->wasted_size) {
jeb->dirty_size += jeb->wasted_size;
c->dirty_size += jeb->wasted_size;
c->wasted_size -= jeb->wasted_size;
jeb->wasted_size = 0;
}
return jffs2_scan_classify_jeb(c, jeb);
}
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