/*
* Miscellaneous routines implementation for MSDOS filesystem
*
* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
* Author: Eugeny S. Mints <Eugeny.Mints@oktet.ru>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* @(#) $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include <sys/time.h>
#include <unistd.h>
#include <string.h>
#include <assert.h>
#include <rtems/libio_.h>
#include "fat.h"
#include "fat_fat_operations.h"
#include "fat_file.h"
#include "msdos.h"
/* msdos_get_token --
* Routine to get a token (name or separator) from the path.
*
* PARAMETERS:
* path - path to get token from
* ret_token - returned token
* token_len - length of returned token
*
* RETURNS:
* token type, token and token length
*
*/
msdos_token_types_t
msdos_get_token(const char *path, char *ret_token, int *token_len)
{
int rc = RC_OK;
register int i = 0;
msdos_token_types_t type = MSDOS_NAME;
char token[MSDOS_NAME_MAX_WITH_DOT+1];
register char c;
/*
* Copy a name into token. (Remember NULL is a token.)
*/
c = path[i];
while ( (!msdos_is_separator(c)) && (i <= MSDOS_NAME_MAX_WITH_DOT) )
{
token[i] = c;
if ( i == MSDOS_NAME_MAX_WITH_DOT )
return MSDOS_INVALID_TOKEN;
if ( !msdos_is_valid_name_char(c) )
return MSDOS_INVALID_TOKEN;
c = path [++i];
}
/*
* Copy a seperator into token.
*/
if ( i == 0 )
{
token[i] = c;
if ( token[i] != '\0' )
{
i++;
type = MSDOS_CURRENT_DIR;
}
else
type = MSDOS_NO_MORE_PATH;
}
else if (token[ i-1 ] != '\0')
token[i] = '\0';
/*
* Set token_len to the number of characters copied.
*/
*token_len = i;
/*
* If we copied something that was not a seperator see if
* it was a special name.
*/
if ( type == MSDOS_NAME )
{
if ( strcmp( token, "..") == 0 )
{
strcpy(ret_token, MSDOS_DOTDOT_NAME);
type = MSDOS_UP_DIR;
return type;
}
if ( strcmp( token, "." ) == 0 )
{
strcpy(ret_token, MSDOS_DOT_NAME);
type = MSDOS_CURRENT_DIR;
return type;
}
rc = msdos_filename_unix2dos(token, *token_len, ret_token);
if ( rc != RC_OK )
return MSDOS_INVALID_TOKEN;
}
ret_token[MSDOS_NAME_MAX] = '\0';
return type;
}
/* msdos_find_name --
* Find the node which correspondes to the name, open fat-file which
* correspondes to the found node and close fat-file which correspondes
* to the node we searched in.
*
* PARAMETERS:
* parent_loc - parent node description
* name - name to find
*
* RETURNS:
* RC_OK and updated 'parent_loc' on success, or -1 if error
* occured (errno set apropriately)
*
*/
int
msdos_find_name(
rtems_filesystem_location_info_t *parent_loc,
char *name
)
{
int rc = RC_OK;
msdos_fs_info_t *fs_info = parent_loc->mt_entry->fs_info;
fat_file_fd_t *fat_fd = NULL;
fat_auxiliary_t aux;
unsigned short time_val = 0;
unsigned short date = 0;
unsigned char node_entry[MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE];
memset(node_entry, 0, MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE);
/*
* find the node which correspondes to the name in the directory pointed by
* 'parent_loc'
*/
rc = msdos_get_name_node(parent_loc, name, &aux, node_entry);
if (rc != RC_OK)
return rc;
/* open fat-file corresponded to the found node */
rc = fat_file_open(parent_loc->mt_entry, aux.cln, aux.ofs, &fat_fd);
if (rc != RC_OK)
return rc;
/*
* I don't like this if, but: we should do it , or should write new file
* size and first cluster num to the disk after each write operation
* (even if one byte is written - that is TOO non-optimize) because
* otherwise real values of these fields stored in fat-file descriptor
* may be accidentely rewritten with wrong values stored on the disk
*/
if (fat_fd->links_num == 1)
{
fat_fd->info_cln = aux.cln;
fat_fd->info_ofs = aux.ofs;
fat_fd->cln = MSDOS_EXTRACT_CLUSTER_NUM(node_entry);
fat_fd->first_char = *MSDOS_DIR_NAME(node_entry);
time_val = *MSDOS_DIR_WRITE_TIME(node_entry);
date = *MSDOS_DIR_WRITE_DATE(node_entry);
fat_fd->mtime = msdos_date_dos2unix(CF_LE_W(time_val), CF_LE_W(date));
if ((*MSDOS_DIR_ATTR(node_entry)) & MSDOS_ATTR_DIRECTORY)
{
fat_fd->fat_file_type = FAT_DIRECTORY;
fat_fd->size_limit = MSDOS_MAX_DIR_LENGHT;
rc = fat_file_size(parent_loc->mt_entry, fat_fd);
if (rc != RC_OK)
{
fat_file_close(parent_loc->mt_entry, fat_fd);
return rc;
}
}
else
{
fat_fd->fat_file_size = CF_LE_L(*MSDOS_DIR_FILE_SIZE(node_entry));
fat_fd->fat_file_type = FAT_FILE;
fat_fd->size_limit = MSDOS_MAX_FILE_SIZE;
}
/* these data is not actual for zero-length fat-file */
fat_fd->map.file_cln = 0;
fat_fd->map.disk_cln = fat_fd->cln;
if ((fat_fd->fat_file_size != 0) &&
(fat_fd->fat_file_size <= fs_info->fat.vol.bpc))
{
fat_fd->map.last_cln = fat_fd->cln;
}
else
{
fat_fd->map.last_cln = FAT_UNDEFINED_VALUE;
}
}
/* close fat-file corresponded to the node we searched in */
rc = fat_file_close(parent_loc->mt_entry, parent_loc->node_access);
if (rc != RC_OK)
{
fat_file_close(parent_loc->mt_entry, fat_fd);
return rc;
}
/* update node_info_ptr field */
parent_loc->node_access = fat_fd;
return rc;
}
/* msdos_get_name_node --
* This routine is used in two ways: for a new mode creation (a) or for
* search the node which correspondes to the name parameter (b).
* In case (a) 'name' should be set up to NULL and 'name_dir_entry' should
* point to initialized 32 bytes structure described a new node.
* In case (b) 'name' should contain a valid string.
*
* (a): reading fat-file which correspondes to directory we are going to
* create node in. If free slot is found write contents of
* 'name_dir_entry' into it. If reach end of fat-file and no free
* slot found, write 32 bytes to the end of fat-file.
*
* (b): reading fat-file which correspondes to directory and trying to
* find slot with the name field == 'name' parameter
*
*
* PARAMETERS:
* parent_loc - node description to create node in or to find name in
* name - NULL or name to find
* paux - identify a node location on the disk -
* cluster num and offset inside the cluster
* name_dir_entry - node to create/placeholder for found node (IN/OUT)
*
* RETURNS:
* RC_OK, filled aux_struct_ptr and name_dir_entry on success, or -1 if
* error occured (errno set apropriately)
*
*/
int
msdos_get_name_node(
rtems_filesystem_location_info_t *parent_loc,
char *name,
fat_auxiliary_t *paux,
char *name_dir_entry
)
{
int rc = RC_OK;
ssize_t ret = 0;
msdos_fs_info_t *fs_info = parent_loc->mt_entry->fs_info;
fat_file_fd_t *fat_fd = parent_loc->node_access;
uint32_t dotdot_cln = 0;
/* find name in fat-file which correspondes to the directory */
rc = msdos_find_name_in_fat_file(parent_loc->mt_entry, fat_fd, name, paux,
name_dir_entry);
if ((rc != RC_OK) && (rc != MSDOS_NAME_NOT_FOUND_ERR))
return rc;
/* if we search for valid name and name not found -> return */
if ((rc == MSDOS_NAME_NOT_FOUND_ERR) && (name != NULL))
return rc;
/*
* if we try to create new entry and the directory is not big enough
* currently - try to enlarge directory
*/
if ((rc == MSDOS_NAME_NOT_FOUND_ERR) && (name == NULL))
{
ret = fat_file_write(parent_loc->mt_entry, fat_fd,
fat_fd->fat_file_size,
MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE,
name_dir_entry);
if (ret == -1)
return -1;
/* on success directory is enlarged by a new cluster */
fat_fd->fat_file_size += fs_info->fat.vol.bpc;
/* get cluster num where a new node located */
rc = fat_file_ioctl(parent_loc->mt_entry, fat_fd, F_CLU_NUM,
fat_fd->fat_file_size - 1, &paux->cln);
if (rc != RC_OK)
return rc;
/*
* if new cluster allocated succesfully then new node is at very
* beginning of the cluster (offset is computed in bytes)
*/
paux->ofs = 0;
return RC_OK;
}
/*
* if we have deal with ".." - it is a special case :(((
*
* Really, we should return cluster num and offset not of ".." slot, but
* slot which correspondes to real directory name.
*/
if ((rc == RC_OK) && (name != NULL))
{
if (strncmp(name, MSDOS_DOTDOT_NAME, MSDOS_SHORT_NAME_LEN) == 0)
{
dotdot_cln = MSDOS_EXTRACT_CLUSTER_NUM((name_dir_entry));
/* are we right under root dir ? */
if (dotdot_cln == 0)
{
/*
* we can relax about first_char field - it never should be
* used for root dir
*/
paux->cln = FAT_ROOTDIR_CLUSTER_NUM;
paux->ofs = 0;
}
else
{
rc = msdos_get_dotdot_dir_info_cluster_num_and_offset(
parent_loc->mt_entry,
dotdot_cln,
paux,
name_dir_entry
);
if (rc != RC_OK)
return rc;
}
}
}
return rc;
}
/*
* msdos_get_dotdot_dir_info_cluster_num_and_offset
*
* Unfortunately, in general, we cann't work here in fat-file ideologic
* (open fat_file "..", get ".." and ".", open "..", find an entry ...)
* because if we open
* fat-file ".." it may happend that we have two different fat-file
* descriptors ( for real name of directory and ".." name ) for a single
* file ( cluster num of both pointers to the same cluster )
* But...we do it because we protected by semaphore
*
*/
/* msdos_get_dotdot_dir_info_cluster_num_and_offset --
* Get cluster num and offset not of ".." slot, but slot which correspondes
* to real directory name.
*
* PARAMETERS:
* mt_entry - mount table entry
* cln - data cluster num extracted drom ".." slot
* paux - identify a node location on the disk -
* number of cluster and offset inside the cluster
* dir_entry - placeholder for found node
*
* RETURNS:
* RC_OK, filled 'paux' and 'dir_entry' on success, or -1 if error occured
* (errno set apropriately)
*
*/
int
msdos_get_dotdot_dir_info_cluster_num_and_offset(
rtems_filesystem_mount_table_entry_t *mt_entry,
uint32_t cln,
fat_auxiliary_t *paux,
char *dir_entry
)
{
int rc = RC_OK;
msdos_fs_info_t *fs_info = mt_entry->fs_info;
fat_file_fd_t *fat_fd = NULL;
unsigned char dot_node[MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE];
unsigned char dotdot_node[MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE];
unsigned char cur_node[MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE];
uint32_t cl4find = 0;
memset(dot_node, 0, MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE);
memset(dotdot_node, 0, MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE);
memset(cur_node, 0, MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE);
/*
* open fat-file corresponded to ".."
*/
rc = fat_file_open(mt_entry, paux->cln, paux->ofs, &fat_fd);
if (rc != RC_OK)
return rc;
fat_fd->info_cln = paux->cln;
fat_fd->info_ofs = paux->ofs;
fat_fd->cln = cln;
fat_fd->fat_file_type = FAT_DIRECTORY;
fat_fd->size_limit = MSDOS_MAX_DIR_LENGHT;
fat_fd->map.file_cln = 0;
fat_fd->map.disk_cln = fat_fd->cln;
rc = fat_file_size(mt_entry, fat_fd);
if (rc != RC_OK)
{
fat_file_close(mt_entry, fat_fd);
return rc;
}
/* find "." node in opened directory */
rc = msdos_find_name_in_fat_file(mt_entry, fat_fd, MSDOS_DOT_NAME, paux,
dot_node);
if (rc != RC_OK)
{
fat_file_close(mt_entry, fat_fd);
return rc;
}
/* find ".." node in opened directory */
rc = msdos_find_name_in_fat_file(mt_entry, fat_fd, MSDOS_DOTDOT_NAME, paux,
dotdot_node);
if (rc != RC_OK)
{
fat_file_close(mt_entry, fat_fd);
return rc;
}
cl4find = MSDOS_EXTRACT_CLUSTER_NUM(dot_node);
/* close fat-file corresponded to ".." directory */
rc = fat_file_close(mt_entry, fat_fd);
if ( rc != RC_OK )
return rc;
if ( (MSDOS_EXTRACT_CLUSTER_NUM(dotdot_node)) == 0)
{
/*
* we handle root dir for all FAT types in the same way with the
* ordinary directories ( through fat_file_* calls )
*/
paux->cln = FAT_ROOTDIR_CLUSTER_NUM;
paux->ofs = 0;
}
/* open fat-file corresponded to second ".." */
rc = fat_file_open(mt_entry, paux->cln, paux->ofs, &fat_fd);
if (rc != RC_OK)
return rc;
fat_fd->info_cln = paux->cln;
fat_fd->info_ofs = paux->ofs;
if ((MSDOS_EXTRACT_CLUSTER_NUM(dotdot_node)) == 0)
fat_fd->cln = fs_info->fat.vol.rdir_cl;
else
fat_fd->cln = MSDOS_EXTRACT_CLUSTER_NUM(dotdot_node);
fat_fd->fat_file_type = FAT_DIRECTORY;
fat_fd->size_limit = MSDOS_MAX_DIR_LENGHT;
fat_fd->map.file_cln = 0;
fat_fd->map.disk_cln = fat_fd->cln;
rc = fat_file_size(mt_entry, fat_fd);
if (rc != RC_OK)
{
fat_file_close(mt_entry, fat_fd);
return rc;
}
/* in this directory find slot with specified cluster num */
rc = msdos_find_node_by_cluster_num_in_fat_file(mt_entry, fat_fd, cl4find,
paux, dir_entry);
if (rc != RC_OK)
{
fat_file_close(mt_entry, fat_fd);
return rc;
}
rc = fat_file_close(mt_entry, fat_fd);
return rc;
}
/* msdos_set_dir_wrt_time_and_date --
* Write last write date and time for a file to the disk (to corresponded
* 32bytes node)
*
* PARAMETERS:
* mt_entry - mount table entry
* fat_fd - fat-file descriptor
*
* RETURNS:
* RC_OK on success, or -1 if error occured (errno set apropriately).
*
*/
int
msdos_set_dir_wrt_time_and_date(
rtems_filesystem_mount_table_entry_t *mt_entry,
fat_file_fd_t *fat_fd
)
{
ssize_t ret1 = 0, ret2 = 0;
msdos_fs_info_t *fs_info = mt_entry->fs_info;
unsigned short time_val;
unsigned short date;
uint32_t sec = 0;
uint32_t byte = 0;
msdos_date_unix2dos(fat_fd->mtime, &time_val, &date);
/*
* calculate input for _fat_block_write: convert (cluster num, offset) to
* (sector num, new offset)
*/
sec = fat_cluster_num_to_sector_num(mt_entry, fat_fd->info_cln);
sec += (fat_fd->info_ofs >> fs_info->fat.vol.sec_log2);
/* byte points to start of 32bytes structure */
byte = fat_fd->info_ofs & (fs_info->fat.vol.bps - 1);
time_val = CT_LE_W(time_val);
ret1 = _fat_block_write(mt_entry, sec, byte + MSDOS_FILE_WTIME_OFFSET,
2, (char *)(&time_val));
date = CT_LE_W(date);
ret2 = _fat_block_write(mt_entry, sec, byte + MSDOS_FILE_WDATE_OFFSET,
2, (char *)(&date));
if ( (ret1 < 0) || (ret2 < 0) )
return -1;
return RC_OK;
}
/* msdos_set_first_cluster_num --
* Write number of first cluster of the file to the disk (to corresponded
* 32bytes slot)
*
* PARAMETERS:
* mt_entry - mount table entry
* fat_fd - fat-file descriptor
*
* RETURNS:
* RC_OK on success, or -1 if error occured
*
*/
int
msdos_set_first_cluster_num(
rtems_filesystem_mount_table_entry_t *mt_entry,
fat_file_fd_t *fat_fd
)
{
ssize_t ret1 = 0, ret2 = 0;
msdos_fs_info_t *fs_info = mt_entry->fs_info;
uint32_t new_cln = fat_fd->cln;
uint16_t le_cl_low = 0;
uint16_t le_cl_hi = 0;
uint32_t sec = 0;
uint32_t byte = 0;
/*
* calculate input for _fat_block_write: convert (cluster num, offset) to
* (sector num, new offset)
*/
sec = fat_cluster_num_to_sector_num(mt_entry, fat_fd->info_cln);
sec += (fat_fd->info_ofs >> fs_info->fat.vol.sec_log2);
/* byte from points to start of 32bytes structure */
byte = fat_fd->info_ofs & (fs_info->fat.vol.bps - 1);
le_cl_low = CT_LE_W((uint16_t )(new_cln & 0x0000FFFF));
ret1 = _fat_block_write(mt_entry, sec,
byte + MSDOS_FIRST_CLUSTER_LOW_OFFSET, 2,
(char *)(&le_cl_low));
le_cl_hi = CT_LE_W((uint16_t )((new_cln & 0xFFFF0000) >> 16));
ret2 = _fat_block_write(mt_entry, sec,
byte + MSDOS_FIRST_CLUSTER_HI_OFFSET, 2,
(char *)(&le_cl_hi));
if ( (ret1 < 0) || (ret2 < 0) )
return -1;
return RC_OK;
}
/* msdos_set_file size --
* Write file size of the file to the disk (to corresponded 32bytes slot)
*
* PARAMETERS:
* mt_entry - mount table entry
* fat_fd - fat-file descriptor
*
* RETURNS:
* RC_OK on success, or -1 if error occured (errno set apropriately).
*
*/
int
msdos_set_file_size(
rtems_filesystem_mount_table_entry_t *mt_entry,
fat_file_fd_t *fat_fd
)
{
ssize_t ret = 0;
msdos_fs_info_t *fs_info = mt_entry->fs_info;
uint32_t le_new_length = 0;
uint32_t sec = 0;
uint32_t byte = 0;
sec = fat_cluster_num_to_sector_num(mt_entry, fat_fd->info_cln);
sec += (fat_fd->info_ofs >> fs_info->fat.vol.sec_log2);
byte = (fat_fd->info_ofs & (fs_info->fat.vol.bps - 1));
le_new_length = CT_LE_L((fat_fd->fat_file_size));
ret = _fat_block_write(mt_entry, sec, byte + MSDOS_FILE_SIZE_OFFSET, 4,
(char *)(&le_new_length));
if ( ret < 0 )
return -1;
return RC_OK;
}
/*
* We should not check whether this routine is called for root dir - it
* never can happend
*/
/* msdos_set_first_char4file_name --
* Write first character of the name of the file to the disk (to
* corresponded 32bytes slot)
*
* PARAMETERS:
* mt_entry - mount table entry
* cl - number of cluster
* ofs - offset inside cluster
* fchar - character to set up
*
* RETURNS:
* RC_OK on success, or -1 if error occured (errno set apropriately)
*
*/
int
msdos_set_first_char4file_name(
rtems_filesystem_mount_table_entry_t *mt_entry,
uint32_t cl,
uint32_t ofs,
unsigned char fchar
)
{
ssize_t ret = 0;
msdos_fs_info_t *fs_info = mt_entry->fs_info;
uint32_t sec = 0;
uint32_t byte = 0;
sec = fat_cluster_num_to_sector_num(mt_entry, cl);
sec += (ofs >> fs_info->fat.vol.sec_log2);
byte = (ofs & (fs_info->fat.vol.bps - 1));
ret = _fat_block_write(mt_entry, sec, byte + MSDOS_FILE_NAME_OFFSET, 1,
&fchar);
if ( ret < 0)
return -1;
return RC_OK;
}
/* msdos_dir_is_empty --
* Check whether directory which correspondes to the fat-file descriptor is
* empty.
*
* PARAMETERS:
* mt_entry - mount table entry
* fat_fd - fat-file descriptor
* ret_val - placeholder for result
*
* RETURNS:
* RC_OK on success, or -1 if error occured
*
*/
int
msdos_dir_is_empty(
rtems_filesystem_mount_table_entry_t *mt_entry,
fat_file_fd_t *fat_fd,
rtems_boolean *ret_val
)
{
ssize_t ret = 0;
msdos_fs_info_t *fs_info = mt_entry->fs_info;
uint32_t j = 0, i = 0;
/* dir is not empty */
*ret_val = FALSE;
while ((ret = fat_file_read(mt_entry, fat_fd, j * fs_info->fat.vol.bps,
fs_info->fat.vol.bps,
fs_info->cl_buf)) != FAT_EOF)
{
if (ret < MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE)
return -1;
assert(ret == fs_info->fat.vol.bps);
for (i = 0;
i < fs_info->fat.vol.bps;
i += MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE)
{
if (((*MSDOS_DIR_NAME(fs_info->cl_buf + i)) ==
MSDOS_THIS_DIR_ENTRY_EMPTY) ||
(strncmp(MSDOS_DIR_NAME((fs_info->cl_buf + i)), MSDOS_DOT_NAME,
MSDOS_SHORT_NAME_LEN) == 0) ||
(strncmp(MSDOS_DIR_NAME((fs_info->cl_buf + i)),
MSDOS_DOTDOT_NAME,
MSDOS_SHORT_NAME_LEN) == 0))
continue;
if ((*MSDOS_DIR_NAME(fs_info->cl_buf + i)) ==
MSDOS_THIS_DIR_ENTRY_AND_REST_EMPTY)
{
*ret_val = TRUE;
return RC_OK;
}
return RC_OK;
}
j++;
}
*ret_val = TRUE;
return RC_OK;
}
/* msdos_find_name_in_fat_file --
* This routine is used in two ways: for a new mode creation (a) or for
* search the node which correspondes to the 'name' parameter (b).
* In case (a) name should be set up to NULL and 'name_dir_entry' should
* point to initialized 32 bytes structure described a new node.
* In case (b) 'name' should contain a valid string.
*
* (a): reading fat-file corresponded to directory we are going to create
* node in. If found free slot write contents of name_dir_entry into
* it.
*
* (b): reading fat-file corresponded to directory and trying to find slot
* with the name field == name parameter
*
* PARAMETERS:
* mt_entry - mount table entry
* fat_fd - fat-file descriptor
* name - NULL or name to find
* paux - identify a node location on the disk -
* number of cluster and offset inside the cluster
* name_dir_entry - node to create/placeholder for found node
*
* RETURNS:
* RC_OK on success, or error code if error occured (errno set
* appropriately)
*
*/
int
msdos_find_name_in_fat_file(
rtems_filesystem_mount_table_entry_t *mt_entry,
fat_file_fd_t *fat_fd,
char *name,
fat_auxiliary_t *paux,
char *name_dir_entry
)
{
int rc = RC_OK;
ssize_t ret = 0;
msdos_fs_info_t *fs_info = mt_entry->fs_info;
uint32_t i = 0, j = 0;
uint32_t bts2rd = 0;
if (FAT_FD_OF_ROOT_DIR(fat_fd) &&
(fs_info->fat.vol.type & (FAT_FAT12 | FAT_FAT16)))
bts2rd = fat_fd->fat_file_size;
else
bts2rd = fs_info->fat.vol.bpc;
while ((ret = fat_file_read(mt_entry, fat_fd, (j * bts2rd), bts2rd,
fs_info->cl_buf)) != FAT_EOF)
{
if (ret < MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE)
set_errno_and_return_minus_one(EIO);
assert(ret == bts2rd);
for (i = 0; i < bts2rd; i += MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE)
{
/* is the entry empty ? */
if (((*MSDOS_DIR_NAME(fs_info->cl_buf + i)) ==
MSDOS_THIS_DIR_ENTRY_AND_REST_EMPTY) ||
((*MSDOS_DIR_NAME(fs_info->cl_buf + i)) ==
MSDOS_THIS_DIR_ENTRY_EMPTY))
{
/* whether we are looking for an empty entry */
if (name == NULL)
{
/* get current cluster number */
rc = fat_file_ioctl(mt_entry, fat_fd, F_CLU_NUM,
j * bts2rd, &paux->cln);
if (rc != RC_OK)
return rc;
/* offset is computed in bytes */
paux->ofs = i;
/* write new node entry */
ret = fat_file_write(mt_entry, fat_fd, j * bts2rd + i,
MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE,
name_dir_entry);
if (ret != MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE)
return -1;
/*
* we don't update fat_file_size here - it should not
* increase
*/
return RC_OK;
}
/*
* if name != NULL and there is no more entries in the
* directory - return name-not-found
*/
if (((*MSDOS_DIR_NAME(fs_info->cl_buf + i)) ==
MSDOS_THIS_DIR_ENTRY_AND_REST_EMPTY))
return MSDOS_NAME_NOT_FOUND_ERR;
}
else
{
/* entry not empty and name != NULL -> compare names */
if (name != NULL)
{
if (strncmp(MSDOS_DIR_NAME((fs_info->cl_buf + i)), name,
MSDOS_SHORT_NAME_LEN) == 0)
{
/*
* we get the entry we looked for - fill auxiliary
* structure and copy all 32 bytes of the entry
*/
rc = fat_file_ioctl(mt_entry, fat_fd, F_CLU_NUM,
j * bts2rd, &paux->cln);
if (rc != RC_OK)
return rc;
/* offset is computed in bytes */
paux->ofs = i;
memcpy(name_dir_entry,(fs_info->cl_buf + i),
MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE);
return RC_OK;
}
}
}
}
j++;
}
return MSDOS_NAME_NOT_FOUND_ERR;
}
/* msdos_find_node_by_cluster_num_in_fat_file --
* Find node with specified number of cluster in fat-file.
*
* PARAMETERS:
* mt_entry - mount table entry
* fat_fd - fat-file descriptor
* cl4find - number of cluster to find
* paux - identify a node location on the disk -
* cluster num and offset inside the cluster
* dir_entry - placeholder for found node
*
* RETURNS:
* RC_OK on success, or error code if error occured
*
*/
int
msdos_find_node_by_cluster_num_in_fat_file(
rtems_filesystem_mount_table_entry_t *mt_entry,
fat_file_fd_t *fat_fd,
uint32_t cl4find,
fat_auxiliary_t *paux,
char *dir_entry
)
{
int rc = RC_OK;
ssize_t ret = 0;
msdos_fs_info_t *fs_info = mt_entry->fs_info;
uint32_t bts2rd = 0;
uint32_t i = 0, j = 0;
if (FAT_FD_OF_ROOT_DIR(fat_fd) &&
(fs_info->fat.vol.type & (FAT_FAT12 | FAT_FAT16)))
bts2rd = fat_fd->fat_file_size;
else
bts2rd = fs_info->fat.vol.bpc;
while ((ret = fat_file_read(mt_entry, fat_fd, j * bts2rd, bts2rd,
fs_info->cl_buf)) != FAT_EOF)
{
if ( ret < MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE )
set_errno_and_return_minus_one( EIO );
assert(ret == bts2rd);
for (i = 0; i < bts2rd; i += MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE)
{
/* if this and all rest entries are empty - return not-found */
if ((*MSDOS_DIR_NAME(fs_info->cl_buf + i)) ==
MSDOS_THIS_DIR_ENTRY_AND_REST_EMPTY)
return MSDOS_NAME_NOT_FOUND_ERR;
/* if this entry is empty - skip it */
if ((*MSDOS_DIR_NAME(fs_info->cl_buf + i)) ==
MSDOS_THIS_DIR_ENTRY_EMPTY)
continue;
/* if get a non-empty entry - compare clusters num */
if (MSDOS_EXTRACT_CLUSTER_NUM((fs_info->cl_buf + i)) == cl4find)
{
/* on success fill aux structure and copy all 32 bytes */
rc = fat_file_ioctl(mt_entry, fat_fd, F_CLU_NUM, j * bts2rd,
&paux->cln);
if (rc != RC_OK)
return rc;
paux->ofs = i;
memcpy(dir_entry, fs_info->cl_buf + i,
MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE);
return RC_OK;
}
}
j++;
}
return MSDOS_NAME_NOT_FOUND_ERR;
}
