/** * \file * <!-- * This file is part of BeRTOS. * * Bertos is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * As a special exception, you may use this file as part of a free software * library without restriction. Specifically, if other files instantiate * templates or use macros or inline functions from this file, or you compile * this file and link it with other files to produce an executable, this * file does not by itself cause the resulting executable to be covered by * the GNU General Public License. This exception does not however * invalidate any other reasons why the executable file might be covered by * the GNU General Public License. * * Copyright 2011 Develer S.r.l. (http://www.develer.com/) * * --> * * \brief KBlock block size reducer * * This module allows access to a KBlock device using a smaller block * size than the native one exported by the device. * Note that the device being remapped needs either to be opened in buffered * mode or to support partial writes. * * \author Stefano Fedrigo <aleph@develer.com> * * $WIZ$ module_depends = "kblock" */ #include "reblock.h" #include <string.h> /* memset */ static size_t reblock_readDirect(struct KBlock *b, block_idx_t idx, void *buf, size_t offset, size_t size) { Reblock *r = REBLOCK_CAST(b); offset += idx % (r->native_fd->blk_size / r->fd.blk_size) * r->fd.blk_size; idx = idx / (r->native_fd->blk_size / r->fd.blk_size); return kblock_read(r->native_fd, idx, buf, offset, size); } static size_t reblock_writeDirect(struct KBlock *b, block_idx_t idx, const void *buf, size_t offset, size_t size) { Reblock *r = REBLOCK_CAST(b); offset += idx % (r->native_fd->blk_size / r->fd.blk_size) * r->fd.blk_size; idx = idx / (r->native_fd->blk_size / r->fd.blk_size); return kblock_write(r->native_fd, idx, buf, offset, size); } static int reblock_error(struct KBlock *b) { return kblock_error(REBLOCK_CAST(b)->native_fd); } static void reblock_clearerr(struct KBlock *b) { kblock_clearerr(REBLOCK_CAST(b)->native_fd); } static int reblock_close(struct KBlock *b) { return kblock_close(REBLOCK_CAST(b)->native_fd); } static const KBlockVTable reblock_vt = { .readDirect = reblock_readDirect, .writeDirect = reblock_writeDirect, .error = reblock_error, .clearerr = reblock_clearerr, .close = reblock_close, }; /* * Initialize reblock device. * * \param rbl kblock reblock device * \param native_fd kblock descriptor of the reblocked device * \param new_blk_size new block size to export * * \note new block size is required to be a submultiple of the * native device block size. */ void reblock_init(Reblock *rbl, KBlock *native_fd, size_t new_blk_size) { ASSERT(new_blk_size); ASSERT(new_blk_size < native_fd->blk_size); ASSERT(native_fd->blk_size % new_blk_size == 0); ASSERT(kblock_buffered(native_fd) || kblock_partialWrite(native_fd)); memset(rbl, 0, sizeof(Reblock)); DB(rbl->fd.priv.type = KBT_REBLOCK); rbl->fd.blk_size = new_blk_size; rbl->fd.blk_cnt = native_fd->blk_cnt * (native_fd->blk_size / new_blk_size); rbl->fd.priv.flags |= KB_PARTIAL_WRITE; rbl->fd.priv.vt = &reblock_vt; rbl->native_fd = native_fd; }