ntfs readdir的速度太慢

来源：互联网发布：域名备案之后怎么用编辑：程序博客网时间：2024/04/30 06:29

也是移植到ucos平台上的问题.

跟踪后发现是ntfs_filldir太花时间,其中主要是ntfs_attr_name_get/ntfs_attr_name_free花的时间比较多(malloc/free).

static int ntfs_filldir(ntfs_inode *dir_ni, s64 *pos, u8 ivcn_bits,const INDEX_TYPE index_type, void *iu, INDEX_ENTRY *ie,void *dirent, struct file_info* info){FILE_NAME_ATTR *fn = &ie->key.file_name;unsigned dt_type;MFT_REF mref;//tchar_t* filename;ntfs_log_enter("Entering %s\n", __FUNCTION__);//ntfs_log_trace("file name is %s\n", fn->file_name);//<strong>filename = ntfs_attr_name_get(fn->file_name, fn->file_name_length);</strong>//dump_fname(filename, fn->file_name_length * sizeof(tchar_t));//ntfs_log_trace("%c%c%c%c%c   %lld    %s\n",(fn->file_attributes & FILE_ATTR_I30_INDEX_PRESENT) ? 'D' : '-',(fn->file_attributes & FILE_ATTR_READONLY) ? 'R' : '-',(fn->file_attributes & FILE_ATTR_HIDDEN) ? 'H' : '-',(fn->file_attributes & FILE_ATTR_SYSTEM) ? 'S' : '-',(fn->file_attributes & FILE_ATTR_ARCHIVE) ? 'A' : '-',fn->data_size, fn->file_name);info->flag = (fn->file_attributes & FILE_ATTR_I30_INDEX_PRESENT) ? FILE_DIR : FILE_REGULAR; // 0 means regular file, 1 means dirinfo->is_system_file = (fn->file_attributes & FILE_ATTR_SYSTEM) ? 1 : 0;info->is_hidden_file = (fn->file_attributes & FILE_ATTR_HIDDEN) ? 1 : 0;info->fattr = fn->file_attributes;info->fsize = fn->data_size;/* Advance the position even if going to skip the entry. */if (index_type == INDEX_TYPE_ALLOCATION)*pos = (u8*)ie - (u8*)iu + (sle64_to_cpu(((INDEX_ALLOCATION *)iu)->index_block_vcn) << ivcn_bits) +dir_ni->vol->mft_record_size;else /* if (index_type == INDEX_TYPE_ROOT) */*pos = (u8*)ie - (u8*)iu;/* Skip root directory self reference entry. */if (MREF_LE(ie->indexed_file) == FILE_root){//<strong>ntfs_attr_name_free(&filename);</strong>return 0;}if (ie->key.file_name.file_attributes & FILE_ATTR_I30_INDEX_PRESENT)dt_type = NTFS_DT_DIR;else if (fn->file_attributes & FILE_ATTR_SYSTEM)dt_type = NTFS_DT_UNKNOWN;elsedt_type = NTFS_DT_REG;<strong>memcpy(dirent, fn->file_name, fn->file_name_length * sizeof(tchar_t));</strong>*(((tchar_t*)dirent) + fn->file_name_length) = '\0';//do not forget the ending \0info->name_len = fn->file_name_length;/* return metadata files and hidden files if requested */mref = le64_to_cpu(ie->indexed_file);//<strong>ntfs_attr_name_free(&filename);</strong>return 0;}

实际上,不要重新去malloc/free,直接用fn->file_name copy 到dirent里面就可以的.

ntfs_attr_name_get/ntfs_attr_name_free反倒是多折腾一次,没必要.

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