/* msdos_file_lseek --
* Process lseek call to the file: extend file if lseek is up to the end
* of the file.
*
* PARAMETERS:
* iop - file control block
* offset - new offset
* whence - predefine directive
*
* RETURNS:
* new offset on success, or -1 if error occured (errno set
* appropriately).
*/
rtems_off64_t
msdos_file_lseek(rtems_libio_t *iop, rtems_off64_t offset, int whence)
{
int rc = RC_OK;
rtems_status_code sc = RTEMS_SUCCESSFUL;
msdos_fs_info_t *fs_info = iop->pathinfo.mt_entry->fs_info;
fat_file_fd_t *fat_fd = iop->pathinfo.node_access;
uint32_t real_size = 0;
sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
if (sc != RTEMS_SUCCESSFUL)
rtems_set_errno_and_return_minus_one(EIO);
rc = fat_file_extend(iop->pathinfo.mt_entry, fat_fd, iop->offset,
&real_size);
if (rc != RC_OK)
{
rtems_semaphore_release(fs_info->vol_sema);
return rc;
}
if (real_size > fat_fd->fat_file_size)
fat_fd->fat_file_size = iop->offset = real_size;
iop->size = fat_fd->fat_file_size;
rtems_semaphore_release(fs_info->vol_sema);
return iop->offset;
}
/* msdos_file_ftruncate --
* Truncate the file.
*
* PARAMETERS:
* iop - file control block
* length - new length
*
* RETURNS:
* RC_OK on success, or -1 if error occured (errno set appropriately).
*/
int
msdos_file_ftruncate(rtems_libio_t *iop, off_t length)
{
int rc = RC_OK;
rtems_status_code sc = RTEMS_SUCCESSFUL;
msdos_fs_info_t *fs_info = iop->pathinfo.mt_entry->fs_info;
fat_file_fd_t *fat_fd = iop->pathinfo.node_access;
uint32_t old_length;
sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
if (sc != RTEMS_SUCCESSFUL)
rtems_set_errno_and_return_minus_one(EIO);
old_length = fat_fd->fat_file_size;
if (length < old_length) {
rc = fat_file_truncate(&fs_info->fat, fat_fd, length);
} else {
uint32_t new_length;
rc = fat_file_extend(&fs_info->fat,
fat_fd,
true,
length,
&new_length);
if (rc == RC_OK && length != new_length) {
fat_file_truncate(&fs_info->fat, fat_fd, old_length);
errno = ENOSPC;
rc = -1;
}
}
if (rc == RC_OK)
{
fat_file_set_file_size(fat_fd, length);
fat_file_set_ctime_mtime(fat_fd, time(NULL));
}
rtems_semaphore_release(fs_info->vol_sema);
return rc;
}
