busybox/e2fsprogs/ext2fs/block.c
2006-03-28 02:35:56 +00:00

438 lines
11 KiB
C

/*
* block.c --- iterate over all blocks in an inode
*
* Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*/
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
struct block_context {
ext2_filsys fs;
int (*func)(ext2_filsys fs,
blk_t *blocknr,
e2_blkcnt_t bcount,
blk_t ref_blk,
int ref_offset,
void *priv_data);
e2_blkcnt_t bcount;
int bsize;
int flags;
errcode_t errcode;
char *ind_buf;
char *dind_buf;
char *tind_buf;
void *priv_data;
};
static int block_iterate_ind(blk_t *ind_block, blk_t ref_block,
int ref_offset, struct block_context *ctx)
{
int ret = 0, changed = 0;
int i, flags, limit, offset;
blk_t *block_nr;
limit = ctx->fs->blocksize >> 2;
if (!(ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) &&
!(ctx->flags & BLOCK_FLAG_DATA_ONLY))
ret = (*ctx->func)(ctx->fs, ind_block,
BLOCK_COUNT_IND, ref_block,
ref_offset, ctx->priv_data);
if (!*ind_block || (ret & BLOCK_ABORT)) {
ctx->bcount += limit;
return ret;
}
if (*ind_block >= ctx->fs->super->s_blocks_count ||
*ind_block < ctx->fs->super->s_first_data_block) {
ctx->errcode = EXT2_ET_BAD_IND_BLOCK;
ret |= BLOCK_ERROR;
return ret;
}
ctx->errcode = ext2fs_read_ind_block(ctx->fs, *ind_block,
ctx->ind_buf);
if (ctx->errcode) {
ret |= BLOCK_ERROR;
return ret;
}
block_nr = (blk_t *) ctx->ind_buf;
offset = 0;
if (ctx->flags & BLOCK_FLAG_APPEND) {
for (i = 0; i < limit; i++, ctx->bcount++, block_nr++) {
flags = (*ctx->func)(ctx->fs, block_nr, ctx->bcount,
*ind_block, offset,
ctx->priv_data);
changed |= flags;
if (flags & BLOCK_ABORT) {
ret |= BLOCK_ABORT;
break;
}
offset += sizeof(blk_t);
}
} else {
for (i = 0; i < limit; i++, ctx->bcount++, block_nr++) {
if (*block_nr == 0)
continue;
flags = (*ctx->func)(ctx->fs, block_nr, ctx->bcount,
*ind_block, offset,
ctx->priv_data);
changed |= flags;
if (flags & BLOCK_ABORT) {
ret |= BLOCK_ABORT;
break;
}
offset += sizeof(blk_t);
}
}
if (changed & BLOCK_CHANGED) {
ctx->errcode = ext2fs_write_ind_block(ctx->fs, *ind_block,
ctx->ind_buf);
if (ctx->errcode)
ret |= BLOCK_ERROR | BLOCK_ABORT;
}
if ((ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) &&
!(ctx->flags & BLOCK_FLAG_DATA_ONLY) &&
!(ret & BLOCK_ABORT))
ret |= (*ctx->func)(ctx->fs, ind_block,
BLOCK_COUNT_IND, ref_block,
ref_offset, ctx->priv_data);
return ret;
}
static int block_iterate_dind(blk_t *dind_block, blk_t ref_block,
int ref_offset, struct block_context *ctx)
{
int ret = 0, changed = 0;
int i, flags, limit, offset;
blk_t *block_nr;
limit = ctx->fs->blocksize >> 2;
if (!(ctx->flags & (BLOCK_FLAG_DEPTH_TRAVERSE |
BLOCK_FLAG_DATA_ONLY)))
ret = (*ctx->func)(ctx->fs, dind_block,
BLOCK_COUNT_DIND, ref_block,
ref_offset, ctx->priv_data);
if (!*dind_block || (ret & BLOCK_ABORT)) {
ctx->bcount += limit*limit;
return ret;
}
if (*dind_block >= ctx->fs->super->s_blocks_count ||
*dind_block < ctx->fs->super->s_first_data_block) {
ctx->errcode = EXT2_ET_BAD_DIND_BLOCK;
ret |= BLOCK_ERROR;
return ret;
}
ctx->errcode = ext2fs_read_ind_block(ctx->fs, *dind_block,
ctx->dind_buf);
if (ctx->errcode) {
ret |= BLOCK_ERROR;
return ret;
}
block_nr = (blk_t *) ctx->dind_buf;
offset = 0;
if (ctx->flags & BLOCK_FLAG_APPEND) {
for (i = 0; i < limit; i++, block_nr++) {
flags = block_iterate_ind(block_nr,
*dind_block, offset,
ctx);
changed |= flags;
if (flags & (BLOCK_ABORT | BLOCK_ERROR)) {
ret |= flags & (BLOCK_ABORT | BLOCK_ERROR);
break;
}
offset += sizeof(blk_t);
}
} else {
for (i = 0; i < limit; i++, block_nr++) {
if (*block_nr == 0) {
ctx->bcount += limit;
continue;
}
flags = block_iterate_ind(block_nr,
*dind_block, offset,
ctx);
changed |= flags;
if (flags & (BLOCK_ABORT | BLOCK_ERROR)) {
ret |= flags & (BLOCK_ABORT | BLOCK_ERROR);
break;
}
offset += sizeof(blk_t);
}
}
if (changed & BLOCK_CHANGED) {
ctx->errcode = ext2fs_write_ind_block(ctx->fs, *dind_block,
ctx->dind_buf);
if (ctx->errcode)
ret |= BLOCK_ERROR | BLOCK_ABORT;
}
if ((ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) &&
!(ctx->flags & BLOCK_FLAG_DATA_ONLY) &&
!(ret & BLOCK_ABORT))
ret |= (*ctx->func)(ctx->fs, dind_block,
BLOCK_COUNT_DIND, ref_block,
ref_offset, ctx->priv_data);
return ret;
}
static int block_iterate_tind(blk_t *tind_block, blk_t ref_block,
int ref_offset, struct block_context *ctx)
{
int ret = 0, changed = 0;
int i, flags, limit, offset;
blk_t *block_nr;
limit = ctx->fs->blocksize >> 2;
if (!(ctx->flags & (BLOCK_FLAG_DEPTH_TRAVERSE |
BLOCK_FLAG_DATA_ONLY)))
ret = (*ctx->func)(ctx->fs, tind_block,
BLOCK_COUNT_TIND, ref_block,
ref_offset, ctx->priv_data);
if (!*tind_block || (ret & BLOCK_ABORT)) {
ctx->bcount += limit*limit*limit;
return ret;
}
if (*tind_block >= ctx->fs->super->s_blocks_count ||
*tind_block < ctx->fs->super->s_first_data_block) {
ctx->errcode = EXT2_ET_BAD_TIND_BLOCK;
ret |= BLOCK_ERROR;
return ret;
}
ctx->errcode = ext2fs_read_ind_block(ctx->fs, *tind_block,
ctx->tind_buf);
if (ctx->errcode) {
ret |= BLOCK_ERROR;
return ret;
}
block_nr = (blk_t *) ctx->tind_buf;
offset = 0;
if (ctx->flags & BLOCK_FLAG_APPEND) {
for (i = 0; i < limit; i++, block_nr++) {
flags = block_iterate_dind(block_nr,
*tind_block,
offset, ctx);
changed |= flags;
if (flags & (BLOCK_ABORT | BLOCK_ERROR)) {
ret |= flags & (BLOCK_ABORT | BLOCK_ERROR);
break;
}
offset += sizeof(blk_t);
}
} else {
for (i = 0; i < limit; i++, block_nr++) {
if (*block_nr == 0) {
ctx->bcount += limit*limit;
continue;
}
flags = block_iterate_dind(block_nr,
*tind_block,
offset, ctx);
changed |= flags;
if (flags & (BLOCK_ABORT | BLOCK_ERROR)) {
ret |= flags & (BLOCK_ABORT | BLOCK_ERROR);
break;
}
offset += sizeof(blk_t);
}
}
if (changed & BLOCK_CHANGED) {
ctx->errcode = ext2fs_write_ind_block(ctx->fs, *tind_block,
ctx->tind_buf);
if (ctx->errcode)
ret |= BLOCK_ERROR | BLOCK_ABORT;
}
if ((ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) &&
!(ctx->flags & BLOCK_FLAG_DATA_ONLY) &&
!(ret & BLOCK_ABORT))
ret |= (*ctx->func)(ctx->fs, tind_block,
BLOCK_COUNT_TIND, ref_block,
ref_offset, ctx->priv_data);
return ret;
}
errcode_t ext2fs_block_iterate2(ext2_filsys fs,
ext2_ino_t ino,
int flags,
char *block_buf,
int (*func)(ext2_filsys fs,
blk_t *blocknr,
e2_blkcnt_t blockcnt,
blk_t ref_blk,
int ref_offset,
void *priv_data),
void *priv_data)
{
int i;
int got_inode = 0;
int ret = 0;
blk_t blocks[EXT2_N_BLOCKS]; /* directory data blocks */
struct ext2_inode inode;
errcode_t retval;
struct block_context ctx;
int limit;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
/*
* Check to see if we need to limit large files
*/
if (flags & BLOCK_FLAG_NO_LARGE) {
ctx.errcode = ext2fs_read_inode(fs, ino, &inode);
if (ctx.errcode)
return ctx.errcode;
got_inode = 1;
if (!LINUX_S_ISDIR(inode.i_mode) &&
(inode.i_size_high != 0))
return EXT2_ET_FILE_TOO_BIG;
}
retval = ext2fs_get_blocks(fs, ino, blocks);
if (retval)
return retval;
limit = fs->blocksize >> 2;
ctx.fs = fs;
ctx.func = func;
ctx.priv_data = priv_data;
ctx.flags = flags;
ctx.bcount = 0;
if (block_buf) {
ctx.ind_buf = block_buf;
} else {
retval = ext2fs_get_mem(fs->blocksize * 3, &ctx.ind_buf);
if (retval)
return retval;
}
ctx.dind_buf = ctx.ind_buf + fs->blocksize;
ctx.tind_buf = ctx.dind_buf + fs->blocksize;
/*
* Iterate over the HURD translator block (if present)
*/
if ((fs->super->s_creator_os == EXT2_OS_HURD) &&
!(flags & BLOCK_FLAG_DATA_ONLY)) {
ctx.errcode = ext2fs_read_inode(fs, ino, &inode);
if (ctx.errcode)
goto abort_exit;
got_inode = 1;
if (inode.osd1.hurd1.h_i_translator) {
ret |= (*ctx.func)(fs,
&inode.osd1.hurd1.h_i_translator,
BLOCK_COUNT_TRANSLATOR,
0, 0, priv_data);
if (ret & BLOCK_ABORT)
goto abort_exit;
}
}
/*
* Iterate over normal data blocks
*/
for (i = 0; i < EXT2_NDIR_BLOCKS ; i++, ctx.bcount++) {
if (blocks[i] || (flags & BLOCK_FLAG_APPEND)) {
ret |= (*ctx.func)(fs, &blocks[i],
ctx.bcount, 0, i, priv_data);
if (ret & BLOCK_ABORT)
goto abort_exit;
}
}
if (*(blocks + EXT2_IND_BLOCK) || (flags & BLOCK_FLAG_APPEND)) {
ret |= block_iterate_ind(blocks + EXT2_IND_BLOCK,
0, EXT2_IND_BLOCK, &ctx);
if (ret & BLOCK_ABORT)
goto abort_exit;
} else
ctx.bcount += limit;
if (*(blocks + EXT2_DIND_BLOCK) || (flags & BLOCK_FLAG_APPEND)) {
ret |= block_iterate_dind(blocks + EXT2_DIND_BLOCK,
0, EXT2_DIND_BLOCK, &ctx);
if (ret & BLOCK_ABORT)
goto abort_exit;
} else
ctx.bcount += limit * limit;
if (*(blocks + EXT2_TIND_BLOCK) || (flags & BLOCK_FLAG_APPEND)) {
ret |= block_iterate_tind(blocks + EXT2_TIND_BLOCK,
0, EXT2_TIND_BLOCK, &ctx);
if (ret & BLOCK_ABORT)
goto abort_exit;
}
abort_exit:
if (ret & BLOCK_CHANGED) {
if (!got_inode) {
retval = ext2fs_read_inode(fs, ino, &inode);
if (retval)
return retval;
}
for (i=0; i < EXT2_N_BLOCKS; i++)
inode.i_block[i] = blocks[i];
retval = ext2fs_write_inode(fs, ino, &inode);
if (retval)
return retval;
}
if (!block_buf)
ext2fs_free_mem(&ctx.ind_buf);
return (ret & BLOCK_ERROR) ? ctx.errcode : 0;
}
/*
* Emulate the old ext2fs_block_iterate function!
*/
struct xlate {
int (*func)(ext2_filsys fs,
blk_t *blocknr,
int bcount,
void *priv_data);
void *real_private;
};
#ifdef __TURBOC__
# pragma argsused
#endif
static int xlate_func(ext2_filsys fs, blk_t *blocknr, e2_blkcnt_t blockcnt,
blk_t ref_block EXT2FS_ATTR((unused)),
int ref_offset EXT2FS_ATTR((unused)),
void *priv_data)
{
struct xlate *xl = (struct xlate *) priv_data;
return (*xl->func)(fs, blocknr, (int) blockcnt, xl->real_private);
}
errcode_t ext2fs_block_iterate(ext2_filsys fs,
ext2_ino_t ino,
int flags,
char *block_buf,
int (*func)(ext2_filsys fs,
blk_t *blocknr,
int blockcnt,
void *priv_data),
void *priv_data)
{
struct xlate xl;
xl.real_private = priv_data;
xl.func = func;
return ext2fs_block_iterate2(fs, ino, BLOCK_FLAG_NO_LARGE | flags,
block_buf, xlate_func, &xl);
}