- 根目录:
- fs
- jffs2
- scan.c
/*
* 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/sched.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/pagemap.h>
#include <linux/crc32.h>
#include <linux/compiler.h>
#include "nodelist.h"
#include "summary.h"
#include "debug.h"
#define DEFAULT_EMPTY_SCAN_SIZE 256
#define noisy_printk(noise, fmt, ...) \
do { \
if (*(noise)) { \
pr_notice(fmt, ##__VA_ARGS__); \
(*(noise))--; \
if (!(*(noise))) \
pr_notice("Further such events for this erase block will not be printed\n"); \
} \
} while (0)
static uint32_t pseudo_random;
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);
/* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
* Returning an error will abort the mount - bad checksums etc. should just mark the space
* as dirty.
*/
static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
static inline int min_free(struct jffs2_sb_info *c)
{
uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
return c->wbuf_pagesize;
#endif
return min;
}
static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
return sector_size;
else
return DEFAULT_EMPTY_SCAN_SIZE;
}
static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
{
int ret;
if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
return ret;
if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
return ret;
/* Turned wasted size into dirty, since we apparently
think it's recoverable now. */
jeb->dirty_size += jeb->wasted_size;
c->dirty_size += jeb->wasted_size;
c->wasted_size -= jeb->wasted_size;
jeb->wasted_size = 0;
if (VERYDIRTY(c, jeb->dirty_size)) {
list_add(&jeb->list, &c->very_dirty_list);
} else {
list_add(&jeb->list, &c->dirty_list);
}
return 0;
}
int jffs2_scan_medium(struct jffs2_sb_info *c)
{
int i, ret;
uint32_t empty_blocks = 0, bad_blocks = 0;
unsigned char *flashbuf = NULL;
uint32_t buf_size = 0;
struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
#ifndef __ECOS
size_t pointlen, try_size;
ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen,
(void **)&flashbuf, NULL);
if (!ret && pointlen < c->mtd->size) {
/* Don't muck about if it won't let us point to the whole flash */
jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n",
pointlen);
mtd_unpoint(c->mtd, 0, pointlen);
flashbuf = NULL;
}
if (ret && ret != -EOPNOTSUPP)
jffs2_dbg(1, "MTD point failed %d\n", ret);
#endif
if (!flashbuf) {
/* For NAND it's quicker to read a whole eraseblock at a time,
apparently */
if (jffs2_cleanmarker_oob(c))
try_size = c->sector_size;
else
try_size = PAGE_SIZE;
jffs2_dbg(1, "Trying to allocate readbuf of %zu "
"bytes\n", try_size);
flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size);
if (!flashbuf)
return -ENOMEM;
jffs2_dbg(1, "Allocated readbuf of %zu bytes\n",
try_size);
buf_size = (uint32_t)try_size;
}
if (jffs2_sum_active()) {
s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
if (!s) {
JFFS2_WARNING("Can't allocate memory for summary\n");
ret = -ENOMEM;
goto out;
}
}
for (i=0; i<c->nr_blocks; i++) {
struct jffs2_eraseblock *jeb = &c->blocks[i];
cond_resched();
/* reset summary info for next eraseblock scan */
jffs2_sum_reset_collected(s);
ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
buf_size, s);
if (ret < 0)
goto out;
jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
/* Now decide which list to put it on */
switch(ret) {
case BLK_STATE_ALLFF:
/*
* Empty block. Since we can't be sure it
* was entirely erased, we just queue it for erase
* again. It will be marked as such when the erase
* is complete. Meanwhile we still count it as empty
* for later checks.
*/
empty_blocks++;
list_add(&jeb->list, &c->erase_pending_list);
c->nr_erasing_blocks++;
break;
case BLK_STATE_CLEANMARKER:
/* Only a CLEANMARKER node is valid */
if (!jeb->dirty_size) {
/* It's actually free */
list_add(&jeb->list, &c->free_list);
c->nr_free_blocks++;
} else {
/* Dirt */
jffs2_dbg(1, "Adding all-dirty block at 0x%08x to erase_pending_list\n",
jeb->offset);
list_add(&jeb->list, &c->erase_pending_list);
c->nr_erasing_blocks++;
}
break;
case BLK_STATE_CLEAN:
/* Full (or almost full) of clean data. Clean list */
list_add(&jeb->list, &c->clean_list);
break;
case BLK_STATE_PARTDIRTY:
/* Some data, but not full. Dirty list. */
/* We want to remember the block with most free space
and stick it in the 'nextblock' position to start writing to it. */
if (jeb->free_size > min_free(c) &&
(!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
/* Better candidate for the next writes to go to */
if (c->nextblock) {
ret = file_dirty(c, c->nextblock);
if (ret)
goto out;
/* deleting summary information of the old nextblock */
jffs2_sum_reset_collected(c->summary);
}
/* update collected summary information for the current nextblock */
jffs2_sum_move_collected(c, s);
jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
__func__, jeb->offset);
c->nextblock = jeb;
} else {
ret = file_dirty(c, jeb);
if (ret)
goto out;
}
break;
case BLK_STATE_ALLDIRTY:
/* Nothing valid - not even a clean marker. Needs erasing. */
/* For now we just put it on the erasing list. We'll start the erases later */
jffs2_dbg(1, "Erase block at 0x%08x is not formatted. It will be erased\n",
jeb->offset);
list_add(&jeb->list, &c->erase_pending_list);
c->nr_erasing_blocks++;
break;
case BLK_STATE_BADBLOCK:
jffs2_dbg(1, "Block at 0x%08x is bad\n", jeb->offset);
list_add(&jeb->list, &c->bad_list);
c->bad_size += c->sector_size;
c->free_size -= c->sector_size;
bad_blocks++;
break;
default:
pr_warn("%s(): unknown block state\n", __func__);
BUG();
}
}
/* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
if (c->nextblock && (c->nextblock->dirty_size)) {
c->nextblock->wasted_size += c->nextblock->dirty_size;
c->wasted_size += c->nextblock->dirty_size;
c->dirty_size -= c->nextblock->dirty_size;
c->nextblock->dirty_size = 0;
}
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
/* If we're going to start writing into a block which already
contains data, and the end of the data isn't page-aligned,
skip a little and align it. */
uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
jffs2_dbg(1, "%s(): Skipping %d bytes in nextblock to ensure page alignment\n",
__func__, skip);
jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
jffs2_scan_dirty_space(c, c->nextblock, skip);
}
#endif
if (c->nr_erasing_blocks) {
if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",
empty_blocks, bad_blocks, c->nr_blocks);
ret = -EIO;
goto out;
}
spin_lock(&c->erase_completion_lock);
jffs2_garbage_collect_trigger(c);
spin_unlock(&c->erase_completion_lock);
}
ret = 0;
out:
if (buf_size)
kfree(flashbuf);
#ifndef __ECOS
else
mtd_unpoint(c->mtd, 0, c->mtd->size);
#endif
kfree(s);
return ret;
}
static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
uint32_t ofs, uint32_t len)
{
int ret;
size_t retlen;
ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
if (ret) {
jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n",
len, ofs, ret);
return ret;
}
if (retlen < len) {
jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n",
ofs, retlen);
return -EIO;
}
return 0;
}
int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
{
if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
&& (!jeb->first_node || !ref_next(jeb->first_node)) )
return BLK_STATE_CLEANMARKER;
/* move blocks with max 4 byte dirty space to cleanlist */
else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
c->dirty_size -= jeb->dirty_size;
c->wasted_size += jeb->dirty_size;
jeb->wasted_size += jeb->dirty_size;
jeb->dirty_size = 0;
return BLK_STATE_CLEAN;
} else if (jeb->used_size || jeb->unchecked_size)
return BLK_STATE_PARTDIRTY;
else
return BLK_STATE_ALLDIRTY;
}
#ifdef CONFIG_JFFS2_FS_XATTR
static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_xattr *rx, uint32_t ofs,
struct jffs2_summary *s)
{
struct jffs2_xattr_datum *xd;
uint32_t xid, version, totlen, crc;
int err;
crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
if (crc != je32_to_cpu(rx->node_crc)) {
JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
ofs, je32_to_cpu(rx->node_crc), crc);
if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
return err;
return 0;
}
xid = je32_to_cpu(rx->xid);
version = je32_to_cpu(rx->version);
totlen = PAD(sizeof(struct jffs2_raw_xattr)
+ rx->name_len + 1 + je16_to_cpu(rx->value_len));
if (totlen != je32_to_cpu(rx->totlen)) {
JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
ofs, je32_to_cpu(rx->totlen), totlen);
if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
return err;
return 0;
}
xd = jffs2_setup_xattr_datum(c, xid, version);
if (IS_ERR(xd))
return PTR_ERR(xd);
if (xd->version > version) {
struct jffs2_raw_node_ref *raw
= jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
raw->next_in_ino = xd->node->next_in_ino;
xd->node->next_in_ino = raw;
} else {
xd->version = version;
xd->xprefix = rx->xprefix;
xd->name_len = rx->name_len;
xd->value_len = je16_to_cpu(rx->value_len);
xd->data_crc = je32_to_cpu(rx->data_crc);
jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
}
if (jffs2_sum_active())
jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n",
ofs, xd->xid, xd->version);
return 0;
}
static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_xref *rr, uint32_t ofs,
struct jffs2_summary *s)
{
struct jffs2_xattr_ref *ref;
uint32_t crc;
int err;
crc = crc32(0, rr, sizeof(*rr) - 4);
if (crc != je32_to_cpu(rr->node_crc)) {
JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
ofs, je32_to_cpu(rr->node_crc), crc);
if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
return err;
return 0;
}
if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
ofs, je32_to_cpu(rr->totlen),
PAD(sizeof(struct jffs2_raw_xref)));
if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
return err;
return 0;
}
ref = jffs2_alloc_xattr_ref();
if (!ref)
return -ENOMEM;
/* BEFORE jffs2_build_xattr_subsystem() called,
* and AFTER xattr_ref is marked as a dead xref,
* ref->xid is used to store 32bit xid, xd is not used
* ref->ino is used to store 32bit inode-number, ic is not used
* Thoes variables are declared as union, thus using those
* are exclusive. In a similar way, ref->next is temporarily
* used to chain all xattr_ref object. It's re-chained to
* jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
*/
ref->ino = je32_to_cpu(rr->ino);
ref->xid = je32_to_cpu(rr->xid);
ref->xseqno = je32_to_cpu(rr->xseqno);
if (ref->xseqno > c->highest_xseqno)
c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
ref->next = c->xref_temp;
c->xref_temp = ref;
jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
if (jffs2_sum_active())
jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
ofs, ref->xid, ref->ino);
return 0;
}
#endif
/* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
the flash, XIP-style */
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, max_ofs;
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;
jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs);
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
if (jffs2_cleanmarker_oob(c)) {
int ret;
if (mtd_block_isbad(c->mtd, jeb->offset))
return BLK_STATE_BADBLOCK;
ret = jffs2_check_nand_cleanmarker(c, jeb);
jffs2_dbg(2, "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;
max_ofs = EMPTY_SCAN_SIZE(c->sector_size);
/* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */
while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
ofs += 4;
if (ofs == max_ofs) {
#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);
jffs2_dbg(2, "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
jffs2_dbg(1, "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) {
jffs2_dbg(1, "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) {
pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs);
ofs = PAD(ofs);
continue;
}
if (ofs == prevofs) {
pr_warn("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)) {
jffs2_dbg(1, "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);
jffs2_dbg(1, "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, scan_end;
empty_start = ofs;
ofs += 4;
scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs);
more_empty:
inbuf_ofs = ofs - buf_ofs;
while (inbuf_ofs < scan_end) {
if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
pr_warn("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. */
jffs2_dbg(1, "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)) {
jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n",
EMPTY_SCAN_SIZE(c->sector_size));
return BLK_STATE_CLEANMARKER;
}
if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
scan_end = buf_len;
goto more_empty;
}
/* 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) */
jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n",
empty_start);
break;
}
/* point never reaches here */
scan_end = buf_len;
jffs2_dbg(1, "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) {
pr_warn("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) {
jffs2_dbg(1, "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) {
pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs);
pr_warn("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, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
__func__,
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, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
__func__,
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;
}
if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
/* Eep. Node goes over the end of the erase block. */
pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
ofs, je32_to_cpu(node->totlen));
pr_warn("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 */
jffs2_dbg(2, "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);
jffs2_dbg(1, "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);
jffs2_dbg(1, "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);
jffs2_dbg(1, "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);
jffs2_dbg(1, "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:
jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs);
if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
pr_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) {
pr_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:
pr_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:
pr_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:
jffs2_dbg(1, "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: {
jffs2_dbg(1, "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);
}
}
jffs2_dbg(1, "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);
}
struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
{
struct jffs2_inode_cache *ic;
ic = jffs2_get_ino_cache(c, ino);
if (ic)
return ic;
if (ino > c->highest_ino)
c->highest_ino = ino;
ic = jffs2_alloc_inode_cache();
if (!ic) {
pr_notice("%s(): allocation of inode cache failed\n", __func__);
return NULL;
}
memset(ic, 0, sizeof(*ic));
ic->ino = ino;
ic->nodes = (void *)ic;
jffs2_add_ino_cache(c, ic);
if (ino == 1)
ic->pino_nlink = 1;
return ic;
}
static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
{
struct jffs2_inode_cache *ic;
uint32_t crc, ino = je32_to_cpu(ri->ino);
jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
/* We do very little here now. Just check the ino# to which we should attribute
this node; we can do all the CRC checking etc. later. There's a tradeoff here --
we used to scan the flash once only, reading everything we want from it into
memory, then building all our in-core data structures and freeing the extra
information. Now we allow the first part of the mount to complete a lot quicker,
but we have to go _back_ to the flash in order to finish the CRC checking, etc.
Which means that the _full_ amount of time to get to proper write mode with GC
operational may actually be _longer_ than before. Sucks to be me. */
/* Check the node CRC in any case. */
crc = crc32(0, ri, sizeof(*ri)-8);
if (crc != je32_to_cpu(ri->node_crc)) {
pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
__func__, ofs, je32_to_cpu(ri->node_crc), crc);
/*
* We believe totlen because the CRC on the node
* _header_ was OK, just the node itself failed.
*/
return jffs2_scan_dirty_space(c, jeb,
PAD(je32_to_cpu(ri->totlen)));
}
ic = jffs2_get_ino_cache(c, ino);
if (!ic) {
ic = jffs2_scan_make_ino_cache(c, ino);
if (!ic)
return -ENOMEM;
}
/* Wheee. It worked */
jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
je32_to_cpu(ri->offset),
je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize));
pseudo_random += je32_to_cpu(ri->version);
if (jffs2_sum_active()) {
jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
}
return 0;
}
static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
{
struct jffs2_full_dirent *fd;
struct jffs2_inode_cache *ic;
uint32_t checkedlen;
uint32_t crc;
int err;
jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
/* We don't get here unless the node is still valid, so we don't have to
mask in the ACCURATE bit any more. */
crc = crc32(0, rd, sizeof(*rd)-8);
if (crc != je32_to_cpu(rd->node_crc)) {
pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
__func__, ofs, je32_to_cpu(rd->node_crc), crc);
/* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
return err;
return 0;
}
pseudo_random += je32_to_cpu(rd->version);
/* Should never happen. Did. (OLPC trac #4184)*/
checkedlen = strnlen(rd->name, rd->nsize);
if (checkedlen < rd->nsize) {
pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n",
ofs, checkedlen);
}
fd = jffs2_alloc_full_dirent(checkedlen+1);
if (!fd) {
return -ENOMEM;
}
memcpy(&fd->name, rd->name, checkedlen);
fd->name[checkedlen] = 0;
crc = crc32(0, fd->name, rd->nsize);
if (crc != je32_to_cpu(rd->name_crc)) {
pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
__func__, ofs, je32_to_cpu(rd->name_crc), crc);
jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n",
fd->name, je32_to_cpu(rd->ino));
jffs2_free_full_dirent(fd);
/* FIXME: Why do we believe totlen? */
/* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
return err;
return 0;
}
ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
if (!ic) {
jffs2_free_full_dirent(fd);
return -ENOMEM;
}
fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
PAD(je32_to_cpu(rd->totlen)), ic);
fd->next = NULL;
fd->version = je32_to_cpu(rd->version);
fd->ino = je32_to_cpu(rd->ino);
fd->nhash = full_name_hash(fd->name, checkedlen);
fd->type = rd->type;
jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
if (jffs2_sum_active()) {
jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
}
return 0;
}
static int count_list(struct list_head *l)
{
uint32_t count = 0;
struct list_head *tmp;
list_for_each(tmp, l) {
count++;
}
return count;
}
/* Note: This breaks if list_empty(head). I don't care. You
might, if you copy this code and use it elsewhere :) */
static void rotate_list(struct list_head *head, uint32_t count)
{
struct list_head *n = head->next;
list_del(head);
while(count--) {
n = n->next;
}
list_add(head, n);
}
void jffs2_rotate_lists(struct jffs2_sb_info *c)
{
uint32_t x;
uint32_t rotateby;
x = count_list(&c->clean_list);
if (x) {
rotateby = pseudo_random % x;
rotate_list((&c->clean_list), rotateby);
}
x = count_list(&c->very_dirty_list);
if (x) {
rotateby = pseudo_random % x;
rotate_list((&c->very_dirty_list), rotateby);
}
x = count_list(&c->dirty_list);
if (x) {
rotateby = pseudo_random % x;
rotate_list((&c->dirty_list), rotateby);
}
x = count_list(&c->erasable_list);
if (x) {
rotateby = pseudo_random % x;
rotate_list((&c->erasable_list), rotateby);
}
if (c->nr_erasing_blocks) {
rotateby = pseudo_random % c->nr_erasing_blocks;
rotate_list((&c->erase_pending_list), rotateby);
}
if (c->nr_free_blocks) {
rotateby = pseudo_random % c->nr_free_blocks;
rotate_list((&c->free_list), rotateby);
}
}