/*
* inode.c --- utility routines to read and write inodes
*
* Copyright (C) 1993, 1994, 1995, 1996, 1997 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
#if HAVE_ERRNO_H
#include <errno.h>
#endif
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ext2_fs.h"
#include "ext2fsP.h"
#include "e2image.h"
struct ext2_struct_inode_scan {
errcode_t magic;
ext2_filsys fs;
ext2_ino_t current_inode;
blk_t current_block;
dgrp_t current_group;
ext2_ino_t inodes_left;
blk_t blocks_left;
dgrp_t groups_left;
blk_t inode_buffer_blocks;
char * inode_buffer;
int inode_size;
char * ptr;
int bytes_left;
char *temp_buffer;
errcode_t (*done_group)(ext2_filsys fs,
ext2_inode_scan scan,
dgrp_t group,
void * priv_data);
void * done_group_data;
int bad_block_ptr;
int scan_flags;
int reserved[6];
};
/*
* This routine flushes the icache, if it exists.
*/
errcode_t ext2fs_flush_icache(ext2_filsys fs)
{
int i;
if (!fs->icache)
return 0;
for (i=0; i < fs->icache->cache_size; i++)
fs->icache->cache[i].ino = 0;
fs->icache->buffer_blk = 0;
return 0;
}
static errcode_t create_icache(ext2_filsys fs)
{
errcode_t retval;
if (fs->icache)
return 0;
retval = ext2fs_get_mem(sizeof(struct ext2_inode_cache), &fs->icache);
if (retval)
return retval;
memset(fs->icache, 0, sizeof(struct ext2_inode_cache));
retval = ext2fs_get_mem(fs->blocksize, &fs->icache->buffer);
if (retval) {
ext2fs_free_mem(&fs->icache);
return retval;
}
fs->icache->buffer_blk = 0;
fs->icache->cache_last = -1;
fs->icache->cache_size = 4;
fs->icache->refcount = 1;
retval = ext2fs_get_array(fs->icache->cache_size,
sizeof(struct ext2_inode_cache_ent),
&fs->icache->cache);
if (retval) {
ext2fs_free_mem(&fs->icache->buffer);
ext2fs_free_mem(&fs->icache);
return retval;
}
ext2fs_flush_icache(fs);
return 0;
}
errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
ext2_inode_scan *ret_scan)
{
ext2_inode_scan scan;
errcode_t retval;
errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks);
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
/*
* If fs->badblocks isn't set, then set it --- since the inode
* scanning functions require it.
*/
if (fs->badblocks == 0) {
/*
* Temporarly save fs->get_blocks and set it to zero,
* for compatibility with old e2fsck's.
*/
save_get_blocks = fs->get_blocks;
fs->get_blocks = 0;
retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
if (retval && fs->badblocks) {
ext2fs_badblocks_list_free(fs->badblocks);
fs->badblocks = 0;
}
fs->get_blocks = save_get_blocks;
}
retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan);
if (retval)
return retval;
memset(scan, 0, sizeof(struct ext2_struct_inode_scan));
scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
scan->fs = fs;
scan->inode_size = EXT2_INODE_SIZE(fs->super);
scan->bytes_left = 0;
scan->current_group = 0;
scan->groups_left = fs->group_desc_count - 1;
scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks : 8;
scan->current_block = scan->fs->
group_desc[scan->current_group].bg_inode_table;
scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
scan->blocks_left = scan->fs->inode_blocks_per_group;
retval = ext2fs_get_array(scan->inode_buffer_blocks,
fs->blocksize,
&scan->inode_buffer);
scan->done_group = 0;
scan->done_group_data = 0;
scan->bad_block_ptr = 0;
if (retval) {
ext2fs_free_mem(&scan);
return retval;
}
retval = ext2fs_get_mem(scan->inode_size, &scan->temp_buffer);
if (retval) {
ext2fs_free_mem(&scan->inode_buffer);
ext2fs_free_mem(&scan);
return retval;
}
if (scan->fs->badblocks && scan->fs->badblocks->num)
scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
if (EXT2_HAS_COMPAT_FEATURE(fs->super,
EXT2_FEATURE_COMPAT_LAZY_BG))
scan->scan_flags |= EXT2_SF_DO_LAZY;
*ret_scan = scan;
return 0;
}
void ext2fs_close_inode_scan(ext2_inode_scan scan)
{
if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
return;
ext2fs_free_mem(&scan->inode_buffer);
scan->inode_buffer = NULL;
ext2fs_free_mem(&scan->temp_buffer);
scan->temp_buffer = NULL;
ext2fs_free_mem(&scan);
return;
}
void ext2fs_set_inode_callback(ext2_inode_scan scan,
errcode_t (*done_group)(ext2_filsys fs,
ext2_inode_scan scan,
dgrp_t group,
void * priv_data),
void *done_group_data)
{
if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
return;
scan->done_group = done_group;
scan->done_group_data = done_group_data;
}
int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
int clear_flags)
{
int old_flags;
if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
return 0;
old_flags = scan->scan_flags;
scan->scan_flags &= ~clear_flags;
scan->scan_flags |= set_flags;
return old_flags;
}
/*
* This function is called by ext2fs_get_next_inode when it needs to
* get ready to read in a new blockgroup.
*/
static errcode_t get_next_blockgroup(ext2_inode_scan scan)
{
scan->current_group++;
scan->groups_left--;
scan->current_block = scan->fs->
group_desc[scan->current_group].bg_inode_table;
scan->current_inode = scan->current_group *
EXT2_INODES_PER_GROUP(scan->fs->super);
scan->bytes_left = 0;
scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
scan->blocks_left = scan->fs->inode_blocks_per_group;
return 0;
}
errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
int group)
{
scan->current_group = group - 1;
scan->groups_left = scan->fs->group_desc_count - group;
return get_next_blockgroup(scan);
}
/*
* This function is called by get_next_blocks() to check for bad
* blocks in the inode table.
*
* This function assumes that badblocks_list->list is sorted in
* increasing order.
*/
static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
blk_t *num_blocks)
{
blk_t blk = scan->current_block;
badblocks_list bb = scan->fs->badblocks;
/*
* If the inode table is missing, then obviously there are no
* bad blocks. :-)
*/
if (blk == 0)
return 0;
/*
* If the current block is greater than the bad block listed
* in the bad block list, then advance the pointer until this
* is no longer the case. If we run out of bad blocks, then
* we don't need to do any more checking!
*/
while (blk > bb->list[scan->bad_block_ptr]) {
if (++scan->bad_block_ptr >= bb->num) {
scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
return 0;
}
}
/*
* If the current block is equal to the bad block listed in
* the bad block list, then handle that one block specially.
* (We could try to handle runs of bad blocks, but that
* only increases CPU efficiency by a small amount, at the
* expense of a huge expense of code complexity, and for an
* uncommon case at that.)
*/
if (blk == bb->list[scan->bad_block_ptr]) {
scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
*num_blocks = 1;
if (++scan->bad_block_ptr >= bb->num)
scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
return 0;
}
/*
* If there is a bad block in the range that we're about to
* read in, adjust the number of blocks to read so that we we
* don't read in the bad block. (Then the next block to read
* will be the bad block, which is handled in the above case.)
*/
if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
*num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
return 0;
}
/*
* This function is called by ext2fs_get_next_inode when it needs to
* read in more blocks from the current blockgroup's inode table.
*/
static errcode_t get_next_blocks(ext2_inode_scan scan)
{
blk_t num_blocks;
errcode_t retval;
/*
* Figure out how many blocks to read; we read at most
* inode_buffer_blocks, and perhaps less if there aren't that
* many blocks left to read.
*/
num_blocks = scan->inode_buffer_blocks;
if (num_blocks > scan->blocks_left)
num_blocks = scan->blocks_left;
/*
* If the past block "read" was a bad block, then mark the
* left-over extra bytes as also being bad.
*/
if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
if (scan->bytes_left)
scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
}
/*
* Do inode bad block processing, if necessary.
*/
if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
retval = check_for_inode_bad_blocks(scan, &num_blocks);
if (retval)
return retval;
}
if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
(scan->current_block == 0)) {
memset(scan->inode_buffer, 0,
(size_t) num_blocks * scan->fs->blocksize);
} else {
retval = io_channel_read_blk(scan->fs->io,
scan->current_block,
(int) num_blocks,
scan->inode_buffer);
if (retval)
return EXT2_ET_NEXT_INODE_READ;
}
scan->ptr = scan->inode_buffer;
scan->bytes_left = num_blocks * scan->fs->blocksize;
scan->blocks_left -= num_blocks;
if (scan->current_block)
scan->current_block += num_blocks;
return 0;
}
#if 0
/*
* Returns 1 if the entire inode_buffer has a non-zero size and
* contains all zeros. (Not just deleted inodes, since that means
* that part of the inode table was used at one point; we want all
* zeros, which means that the inode table is pristine.)
*/
static inline int is_empty_scan(ext2_inode_scan scan)
{
int i;
if (scan->bytes_left == 0)
return 0;
for (i=0; i < scan->bytes_left; i++)
if (scan->ptr[i])
return 0;
return 1;
}
#endif
errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
struct ext2_inode *inode, int bufsize)
{
errcode_t retval;
int extra_bytes = 0;
EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
/*
* Do we need to start reading a new block group?
*/
if (scan->inodes_left <= 0) {
force_new_group:
if (scan->done_group) {
retval = (scan->done_group)
(scan->fs, scan, scan->current_group,
scan->done_group_data);
if (retval)
return retval;
}
if (scan->groups_left <= 0) {
*ino = 0;
return 0;
}
retval = get_next_blockgroup(scan);
if (retval)
return retval;
}
/*
* These checks are done outside the above if statement so
* they can be done for block group #0.
*/
if ((scan->scan_flags & EXT2_SF_DO_LAZY) &&
(scan->fs->group_desc[scan->current_group].bg_flags &
EXT2_BG_INODE_UNINIT))
goto force_new_group;
if (scan->current_block == 0) {
if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
goto force_new_group;
} else
return EXT2_ET_MISSING_INODE_TABLE;
}
/*
* Have we run out of space in the inode buffer? If so, we
* need to read in more blocks.
*/
if (scan->bytes_left < scan->inode_size) {
memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
extra_bytes = scan->bytes_left;
retval = get_next_blocks(scan);
if (retval)
return retval;
#if 0
/*
* XXX test Need check for used inode somehow.
* (Note: this is hard.)
*/
if (is_empty_scan(scan))
goto force_new_group;
#endif
}
retval = 0;
if (extra_bytes) {
memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
scan->inode_size - extra_bytes);
scan->ptr += scan->inode_size - extra_bytes;
scan->bytes_left -= scan->inode_size - extra_bytes;
#ifdef EXT2FS_ENABLE_SWAPFS
memset(inode, 0, bufsize);
if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
(scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
ext2fs_swap_inode_full(scan->fs,
(struct ext2_inode_large *) inode,
(struct ext2_inode_large *) scan->temp_buffer,
0, bufsize);
else
#endif
*inode = *((struct ext2_inode *) scan->temp_buffer);
if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
} else {
#ifdef EXT2FS_ENABLE_SWAPFS
memset(inode, 0, bufsize);
if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
(scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
ext2fs_swap_inode_full(scan->fs,
(struct ext2_inode_large *) inode,
(struct ext2_inode_large *) scan->ptr,
0, bufsize);
else
#endif
memcpy(inode, scan->ptr, bufsize);
scan->ptr += scan->inode_size;
scan->bytes_left -= scan->inode_size;
if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
}
scan->inodes_left--;
scan->current_inode++;
*ino = scan->current_inode;
return retval;
}
errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino,
struct ext2_inode *inode)
{
return ext2fs_get_next_inode_full(scan, ino, inode,
sizeof(struct ext2_inode));
}
/*
* Functions to read and write a single inode.
*/
errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode * inode, int bufsize)
{
unsigned long group, block, block_nr, offset;
char *ptr;
errcode_t retval;
int clen, i, inodes_per_block, length;
io_channel io;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
/* Check to see if user has an override function */
if (fs->read_inode) {
retval = (fs->read_inode)(fs, ino, inode);
if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
return retval;
}
/* Create inode cache if not present */
if (!fs->icache) {
retval = create_icache(fs);
if (retval)
return retval;
}
/* Check to see if it's in the inode cache */
if (bufsize == sizeof(struct ext2_inode)) {
/* only old good inode can be retrieve from the cache */
for (i=0; i < fs->icache->cache_size; i++) {
if (fs->icache->cache[i].ino == ino) {
*inode = fs->icache->cache[i].inode;
return 0;
}
}
}
if ((ino == 0) || (ino > fs->super->s_inodes_count))
return EXT2_ET_BAD_INODE_NUM;
if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
block_nr = fs->image_header->offset_inode / fs->blocksize;
block_nr += (ino - 1) / inodes_per_block;
offset = ((ino - 1) % inodes_per_block) *
EXT2_INODE_SIZE(fs->super);
io = fs->image_io;
} else {
group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
EXT2_INODE_SIZE(fs->super);
block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
if (!fs->group_desc[(unsigned)group].bg_inode_table)
return EXT2_ET_MISSING_INODE_TABLE;
block_nr = fs->group_desc[(unsigned)group].bg_inode_table +
block;
io = fs->io;
}
offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
length = EXT2_INODE_SIZE(fs->super);
if (bufsize < length)
length = bufsize;
ptr = (char *) inode;
while (length) {
clen = length;
if ((offset + length) > fs->blocksize)
clen = fs->blocksize - offset;
if (block_nr != fs->icache->buffer_blk) {
retval = io_channel_read_blk(io, block_nr, 1,
fs->icache->buffer);
if (retval)
return retval;
fs->icache->buffer_blk = block_nr;
}
memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
clen);
offset = 0;
length -= clen;
ptr += clen;
block_nr++;
}
#ifdef EXT2FS_ENABLE_SWAPFS
if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
(fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) inode,
(struct ext2_inode_large *) inode,
0, bufsize);
#endif
/* Update the inode cache */
fs->icache->cache_last = (fs->icache->cache_last + 1) %
fs->icache->cache_size;
fs->icache->cache[fs->icache->cache_last].ino = ino;
fs->icache->cache[fs->icache->cache_last].inode = *inode;
return 0;
}
errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode * inode)
{
return ext2fs_read_inode_full(fs, ino, inode,
sizeof(struct ext2_inode));
}
errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode * inode, int bufsize)
{
unsigned long group, block, block_nr, offset;
errcode_t retval = 0;
struct ext2_inode_large temp_inode, *w_inode;
char *ptr;
int clen, i, length;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
/* Check to see if user provided an override function */
if (fs->write_inode) {
retval = (fs->write_inode)(fs, ino, inode);
if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
return retval;
}
/* Check to see if the inode cache needs to be updated */
if (fs->icache) {
for (i=0; i < fs->icache->cache_size; i++) {
if (fs->icache->cache[i].ino == ino) {
fs->icache->cache[i].inode = *inode;
break;
}
}
} else {
retval = create_icache(fs);
if (retval)
return retval;
}
if (!(fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if ((ino == 0) || (ino > fs->super->s_inodes_count))
return EXT2_ET_BAD_INODE_NUM;
length = bufsize;
if (length < EXT2_INODE_SIZE(fs->super))
length = EXT2_INODE_SIZE(fs->super);
if (length > (int) sizeof(struct ext2_inode_large)) {
w_inode = malloc(length);
if (!w_inode)
return ENOMEM;
} else
w_inode = &temp_inode;
memset(w_inode, 0, length);
#ifdef EXT2FS_ENABLE_SWAPFS
if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
(fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))
ext2fs_swap_inode_full(fs, w_inode,
(struct ext2_inode_large *) inode,
1, bufsize);
else
#endif
memcpy(w_inode, inode, bufsize);
group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
EXT2_INODE_SIZE(fs->super);
block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
if (!fs->group_desc[(unsigned) group].bg_inode_table) {
retval = EXT2_ET_MISSING_INODE_TABLE;
goto errout;
}
block_nr = fs->group_desc[(unsigned) group].bg_inode_table + block;
offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
length = EXT2_INODE_SIZE(fs->super);
if (length > bufsize)
length = bufsize;
ptr = (char *) w_inode;
while (length) {
clen = length;
if ((offset + length) > fs->blocksize)
clen = fs->blocksize - offset;
if (fs->icache->buffer_blk != block_nr) {
retval = io_channel_read_blk(fs->io, block_nr, 1,
fs->icache->buffer);
if (retval)
goto errout;
fs->icache->buffer_blk = block_nr;
}
memcpy((char *) fs->icache->buffer + (unsigned) offset,
ptr, clen);
retval = io_channel_write_blk(fs->io, block_nr, 1,
fs->icache->buffer);
if (retval)
goto errout;
offset = 0;
ptr += clen;
length -= clen;
block_nr++;
}
fs->flags |= EXT2_FLAG_CHANGED;
errout:
if (w_inode && w_inode != &temp_inode)
free(w_inode);
return retval;
}
errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode *inode)
{
return ext2fs_write_inode_full(fs, ino, inode,
sizeof(struct ext2_inode));
}
/*
* This function should be called when writing a new inode. It makes
* sure that extra part of large inodes is initialized properly.
*/
errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode *inode)
{
struct ext2_inode *buf;
int size = EXT2_INODE_SIZE(fs->super);
struct ext2_inode_large *large_inode;
errcode_t retval;
if (size == sizeof(struct ext2_inode))
return ext2fs_write_inode_full(fs, ino, inode,
sizeof(struct ext2_inode));
buf = malloc(size);
if (!buf)
return ENOMEM;
memset(buf, 0, size);
*buf = *inode;
large_inode = (struct ext2_inode_large *) buf;
large_inode->i_extra_isize = sizeof(struct ext2_inode_large) -
EXT2_GOOD_OLD_INODE_SIZE;
retval = ext2fs_write_inode_full(fs, ino, buf, size);
free(buf);
return retval;
}
errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks)
{
struct ext2_inode inode;
int i;
errcode_t retval;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (ino > fs->super->s_inodes_count)
return EXT2_ET_BAD_INODE_NUM;
if (fs->get_blocks) {
if (!(*fs->get_blocks)(fs, ino, blocks))
return 0;
}
retval = ext2fs_read_inode(fs, ino, &inode);
if (retval)
return retval;
for (i=0; i < EXT2_N_BLOCKS; i++)
blocks[i] = inode.i_block[i];
return 0;
}
errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino)
{
struct ext2_inode inode;
errcode_t retval;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (ino > fs->super->s_inodes_count)
return EXT2_ET_BAD_INODE_NUM;
if (fs->check_directory) {
retval = (fs->check_directory)(fs, ino);
if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
return retval;
}
retval = ext2fs_read_inode(fs, ino, &inode);
if (retval)
return retval;
if (!LINUX_S_ISDIR(inode.i_mode))
return EXT2_ET_NO_DIRECTORY;
return 0;
}