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libxmount_morphing_raid.c
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libxmount_morphing_raid.c
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/*******************************************************************************
* xmount Copyright (c) 2008-2014 by Gillen Daniel <gillen.dan@pinguin.lu> *
* *
* This program 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 3 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, see <http://www.gnu.org/licenses/>. *
*******************************************************************************/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "../libxmount_morphing.h"
#include "libxmount_morphing_raid.h"
#define LOG_DEBUG(...) { \
LIBXMOUNT_LOG_DEBUG(p_raid_handle->debug,__VA_ARGS__); \
}
/*******************************************************************************
* LibXmount_Morphing API implementation
******************************************************************************/
/*
* LibXmount_Morphing_GetApiVersion
*/
uint8_t LibXmount_Morphing_GetApiVersion() {
return LIBXMOUNT_MORPHING_API_VERSION;
}
/*
* LibXmount_Morphing_GetSupportedFormats
*/
const char* LibXmount_Morphing_GetSupportedTypes() {
return "raid0\0\0";
}
/*
* LibXmount_Morphing_GetFunctions
*/
void LibXmount_Morphing_GetFunctions(ts_LibXmountMorphingFunctions *p_functions)
{
p_functions->CreateHandle=&RaidCreateHandle;
p_functions->DestroyHandle=&RaidDestroyHandle;
p_functions->Morph=&RaidMorph;
p_functions->Size=&RaidSize;
p_functions->Read=&RaidRead;
p_functions->OptionsHelp=&RaidOptionsHelp;
p_functions->OptionsParse=&RaidOptionsParse;
p_functions->GetInfofileContent=&RaidGetInfofileContent;
p_functions->GetErrorMessage=&RaidGetErrorMessage;
p_functions->FreeBuffer=&RaidFreeBuffer;
}
/*******************************************************************************
* Private
******************************************************************************/
/*
* RaidCreateHandle
*/
static int RaidCreateHandle(void **pp_handle,
const char *p_format,
uint8_t debug)
{
pts_RaidHandle p_raid_handle;
// Alloc new handle
p_raid_handle=malloc(sizeof(ts_RaidHandle));
if(p_raid_handle==NULL) return RAID_MEMALLOC_FAILED;
// Init handle values
p_raid_handle->debug=debug;
p_raid_handle->input_images_count=0;
p_raid_handle->chunk_size=RAID_DEFAULT_CHUNKSIZE;
p_raid_handle->chunks_per_image=0;
p_raid_handle->p_input_functions=NULL;
p_raid_handle->morphed_image_size=0;
LOG_DEBUG("Created new LibXmount_Morphing_Raid handle\n");
// Return new handle
*pp_handle=p_raid_handle;
return RAID_OK;
}
/*
* RaidDestroyHandle
*/
static int RaidDestroyHandle(void **pp_handle) {
pts_RaidHandle p_raid_handle=(pts_RaidHandle)*pp_handle;
LOG_DEBUG("Destroying LibXmount_Morphing_Raid handle\n");
// Free handle
free(p_raid_handle);
*pp_handle=NULL;
return RAID_OK;
}
/*
* RaidMorph
*/
static int RaidMorph(void *p_handle,
pts_LibXmountMorphingInputFunctions p_input_functions)
{
pts_RaidHandle p_raid_handle=(pts_RaidHandle)p_handle;
int ret;
uint64_t input_image_size;
uint64_t chunks_per_image;
LOG_DEBUG("Initializing LibXmount_Morphing_Raid\n");
// Set input functions and get image count
p_raid_handle->p_input_functions=p_input_functions;
if(p_raid_handle->
p_input_functions->
ImageCount(&p_raid_handle->input_images_count)!=0)
{
return RAID_CANNOT_GET_IMAGECOUNT;
}
// Calculate chunks per image
for(uint64_t i=0;i<p_raid_handle->input_images_count;i++) {
ret=p_raid_handle->
p_input_functions->
Size(i,&input_image_size);
if(ret!=0) return RAID_CANNOT_GET_IMAGESIZE;
chunks_per_image=input_image_size/p_raid_handle->chunk_size;
LOG_DEBUG("Image %" PRIu64 " can hold a maximum of %" PRIu64 " chunks of %"
PRIu32 " bytes\n",
i,
chunks_per_image,
p_raid_handle->chunk_size);
// The smallest image determines how many chunks are availbale on all images
if(p_raid_handle->chunks_per_image==0) {
p_raid_handle->chunks_per_image=chunks_per_image;
} else if(chunks_per_image<p_raid_handle->chunks_per_image) {
p_raid_handle->chunks_per_image=chunks_per_image;
}
}
LOG_DEBUG("Smallest image holds %" PRIu64 " chunks of %" PRIu32 " bytes\n",
p_raid_handle->chunks_per_image,
p_raid_handle->chunk_size);
// Calculate total raid capacity based on smallest disk
p_raid_handle->morphed_image_size=
p_raid_handle->chunks_per_image*
p_raid_handle->chunk_size*p_raid_handle->input_images_count;
LOG_DEBUG("Total raid capacity is %" PRIu64 " bytes\n",
p_raid_handle->morphed_image_size);
return RAID_OK;
}
/*
* RaidSize
*/
static int RaidSize(void *p_handle, uint64_t *p_size) {
*p_size=((pts_RaidHandle)(p_handle))->morphed_image_size;
return RAID_OK;
}
/*
* RaidRead
*/
static int RaidRead(void *p_handle,
char *p_buf,
off_t offset,
size_t count,
size_t *p_read)
{
pts_RaidHandle p_raid_handle=(pts_RaidHandle)p_handle;
uint64_t cur_chunk;
uint64_t cur_image;
off_t cur_chunk_offset;
off_t cur_image_offset;
size_t cur_count;
int ret;
size_t read;
LOG_DEBUG("Reading %zu bytes at offset %zu from morphed image\n",
count,
offset);
// Make sure read parameters are within morphed image bounds
if(offset>=p_raid_handle->morphed_image_size ||
offset+count>p_raid_handle->morphed_image_size)
{
return RAID_READ_BEYOND_END_OF_IMAGE;
}
// Calculate starting chunk, and chunk offset
cur_chunk=offset/p_raid_handle->chunk_size;
cur_chunk_offset=offset-(cur_chunk*p_raid_handle->chunk_size);
// Init p_read
*p_read=0;
while(count!=0) {
// Calculate image and image offset to read from
cur_image=cur_chunk%p_raid_handle->input_images_count;
cur_image_offset=
(cur_chunk/p_raid_handle->input_images_count)*p_raid_handle->chunk_size;
// Calculate how many bytes to read from current chunk
if(cur_chunk_offset+count>p_raid_handle->chunk_size) {
cur_count=p_raid_handle->chunk_size-cur_chunk_offset;
} else {
cur_count=count;
}
LOG_DEBUG("Reading %zu bytes at offset %zu from image %" PRIu64
" (chunk %" PRIu64 ")\n",
cur_count,
cur_image_offset+cur_chunk_offset,
cur_image,
cur_chunk);
// Read bytes
ret=p_raid_handle->p_input_functions->
Read(cur_image,
p_buf,
cur_image_offset+cur_chunk_offset,
cur_count,
&read);
if(ret!=0 || read!=cur_count) return RAID_CANNOT_READ_DATA;
p_buf+=cur_count;
cur_chunk_offset=0;
count-=cur_count;
cur_chunk++;
(*p_read)+=cur_count;
}
return RAID_OK;
}
/*
* RaidOptionsHelp
*/
static int RaidOptionsHelp(const char **pp_help) {
int ok;
char *p_buf;
ok=asprintf(&p_buf,
" raid_chunksize : Specify the chunk size to use in bytes. "
"Defaults to 524288 (512k).\n");
if(ok<0 || p_buf==NULL) {
*pp_help=NULL;
return RAID_MEMALLOC_FAILED;
}
*pp_help=p_buf;
return RAID_OK;
}
/*
* RaidOptionsParse
*/
static int RaidOptionsParse(void *p_handle,
uint32_t options_count,
const pts_LibXmountOptions *pp_options,
const char **pp_error)
{
pts_RaidHandle p_raid_handle=(pts_RaidHandle)p_handle;
int ok;
uint32_t uint32value;
char *p_buf;
for(uint32_t i=0;i<options_count;i++) {
if(strcmp(pp_options[i]->p_key,"raid_chunksize")) {
// Convert value to uint32
uint32value=StrToUint32(pp_options[i]->p_value,&ok);
if(ok==0 || uint32value==0) {
// Conversion failed, generate error message and return
ok=asprintf(&p_buf,
"Unable to parse value '%s' of '%s' as valid 32bit number",
pp_options[i]->p_value,
pp_options[i]->p_key);
if(ok<0 || *pp_error==NULL) {
*pp_error=NULL;
return RAID_MEMALLOC_FAILED;
}
*pp_error=p_buf;
return RAID_CANNOT_PARSE_OPTION;
}
LOG_DEBUG("Setting chunk size to %" PRIu32 " bytes\n",uint32value);
// Conversion ok, save value and mark option as valid
p_raid_handle->chunk_size=uint32value;
pp_options[i]->valid=1;
continue;
}
}
return RAID_OK;
}
/*
* RaidGetInfofileContent
*/
static int RaidGetInfofileContent(void *p_handle,
const char **pp_info_buf)
{
pts_RaidHandle p_raid_handle=(pts_RaidHandle)p_handle;
int ret;
char *p_buf;
ret=asprintf(&p_buf,
"Simulating RAID level 0 over %" PRIu64 " disks.\n"
"Chunk size: %" PRIu32 " bytes\n"
"Chunks per disk: %" PRIu64 "\n"
"Total capacity: %" PRIu64 " bytes (%0.3f GiB)\n",
p_raid_handle->input_images_count,
p_raid_handle->chunk_size,
p_raid_handle->chunks_per_image,
p_raid_handle->morphed_image_size,
p_raid_handle->morphed_image_size/(1024.0*1024.0*1024.0));
if(ret<0 || *pp_info_buf==NULL) return RAID_MEMALLOC_FAILED;
*pp_info_buf=p_buf;
return RAID_OK;
}
/*
* RaidGetErrorMessage
*/
static const char* RaidGetErrorMessage(int err_num) {
switch(err_num) {
case RAID_MEMALLOC_FAILED:
return "Unable to allocate memory";
break;
case RAID_CANNOT_GET_IMAGECOUNT:
return "Unable to get input image count";
break;
case RAID_CANNOT_GET_IMAGESIZE:
return "Unable to get input image size";
break;
case RAID_READ_BEYOND_END_OF_IMAGE:
return "Unable to read data: Attempt to read past EOF";
break;
case RAID_CANNOT_READ_DATA:
return "Unable to read data";
break;
case RAID_CANNOT_PARSE_OPTION:
return "Unable to parse library option";
break;
default:
return "Unknown error";
}
}
/*
* RaidFreeBuffer
*/
static void RaidFreeBuffer(void *p_buf) {
free(p_buf);
}

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