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linux-hardened/fs/jffs2/scan.c
Linus Torvalds 8387ff2577 vfs: make the string hashes salt the hash 
We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time.  It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.

A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.

Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.

Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-10 20:21:46 -07:00

1176 lines
35 KiB
C
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/*
* 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;
/* sm->offset maybe wrong but MAGIC maybe right */
if (sumlen > c->sector_size)
goto full_scan;
/* 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;
}
}
full_scan:
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(NULL, 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);
}
}
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