STATIC off_t
fat_seek(fs_handle handle, off_t off, int whence)
{
off_t curr_pos = (off_t) ((fat_file_handle *)handle)->pos;
switch (whence) {
case SEEK_SET:
if (off < 0)
return -EINVAL; /* invalid negative offset */
fat_rewind(handle);
break;
case SEEK_END:
if (off >= 0)
break;
fat_file_handle *h = (fat_file_handle *) handle;
off = (off_t) h->e->DIR_FileSize + off;
if (off < 0)
return -EINVAL;
fat_rewind(handle);
break;
case SEEK_CUR:
if (off < 0) {
off = curr_pos + off;
if (off < 0)
return -EINVAL;
fat_rewind(handle);
}
break;
default:
return -EINVAL;
}
return fat_seek_forward(handle, off);
}
/* open a directory */
DIR * opendir(const char *dirname)
{
DEBUGF("opendir(dirname=\"%s\"\n", dirname);
DIR *dirp = NULL;
file_internal_lock_WRITER();
int rc;
struct dirstr_desc * const dir = alloc_dirstr();
if (!dir)
FILE_ERROR(EMFILE, RC);
rc = open_stream_internal(dirname, FF_DIR, &dir->stream, NULL);
if (rc < 0)
{
DEBUGF("Open failed: %d\n", rc);
FILE_ERROR(ERRNO, RC);
}
#ifdef HAVE_MULTIVOLUME
/* volume counter is relevant only to the system root */
dir->volumecounter = rc > 1 ? 0 : INT_MAX;
#endif /* HAVE_MULTIVOLUME */
fat_rewind(&dir->stream.fatstr);
rewinddir_dirent(&dir->scan);
dirp = (DIR *)dir;
file_error:
file_internal_unlock_WRITER();
return dirp;
}
/* actually do the open gruntwork */
static int open_internal_inner2(const char *path,
struct filestr_desc *file,
unsigned int callflags)
{
int rc;
struct path_component_info compinfo;
rc = open_stream_internal(path, callflags, &file->stream, &compinfo);
if (rc < 0)
{
DEBUGF("Open failed: %d\n", rc);
FILE_ERROR_RETURN(ERRNO, rc * 10 - 1);
}
bool created = false;
if (rc > 0)
{
if (callflags & FF_EXCL)
{
DEBUGF("File exists\n");
FILE_ERROR(EEXIST, -2);
}
if (compinfo.attr & ATTR_DIRECTORY)
{
if ((callflags & FD_WRITE) || !(callflags & FF_ANYTYPE))
{
DEBUGF("File is a directory\n");
FILE_ERROR(EISDIR, -3);
}
compinfo.filesize = MAX_DIRECTORY_SIZE; /* allow file ops */
}
}
else if (callflags & FF_CREAT)
{
if (compinfo.attr & ATTR_DIRECTORY)
{
DEBUGF("File is a directory\n");
FILE_ERROR(EISDIR, -5);
}
/* not found; try to create it */
callflags &= ~FO_TRUNC;
rc = create_stream_internal(&compinfo.parentinfo, compinfo.name,
compinfo.length, ATTR_NEW_FILE, callflags,
&file->stream);
if (rc < 0)
FILE_ERROR(ERRNO, rc * 10 - 6);
created = true;
}
else
{
DEBUGF("File not found\n");
FILE_ERROR(ENOENT, -7);
}
fat_rewind(&file->stream.fatstr);
file->sizep = fileobj_get_sizep(&file->stream);
file->offset = 0;
if (!created)
{
/* size from storage applies to first stream only otherwise it's
already up to date */
const bool first = fileobj_get_flags(&file->stream) & FO_SINGLE;
if (first)
*file->sizep = compinfo.filesize;
if (callflags & FO_TRUNC)
{
/* if the file is kind of "big" then free some space now */
rc = ftruncate_internal(file, 0, *file->sizep >= O_TRUNC_THRESH);
if (rc < 0)
{
DEBUGF("O_TRUNC failed: %d\n", rc);
FILE_ERROR(ERRNO, rc * 10 - 4);
}
}
}
rc = 0;
file_error:
if (rc < 0)
close_stream_internal(&file->stream);
return rc;
}
