make-integrityhuge.c

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/*
 * make-integrityhuge
 *
 * Make a file to test oversize writes
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <stdint.h>
#include <unistd.h>
#include "config.h"
#include "cliserv.h"
#include "nbd.h"

const uint64_t filesize=50*1000*1000;
const uint64_t transactions = 250;

static inline void dowrite(int f, void *buf, size_t len) {
        ssize_t res;

        while(len>0) {
                if((res=write(f, buf, len)) <=0) {
                        perror ("Error writing transactions");
                        exit(1);
                }
                len-=res;
                buf+=res;
        }
}

static inline uint64_t getrandomuint64() {
        uint64_t r=0;
        int i;
        /* RAND_MAX may be as low as 2^15 */
        for (i= 1 ; i<=5; i++)
                r ^= random() ^ (r << 15); 
        return r;
}

int main(int argc, char**argv) {
        struct nbd_request req;
        struct nbd_reply rep;
        uint64_t handle;
        int writefd = 1; /*stdout*/

        req.magic = htonl(NBD_REQUEST_MAGIC);
        rep.magic = htonl(NBD_REPLY_MAGIC);
        rep.error = 0;

        for (handle = 0; handle < transactions; handle++)
        {
                uint64_t offset;
                uint64_t length;
                uint64_t flags;
                uint32_t command;

                /* make the length between 0x400 and the length of the disk -08x800, with all
                 * the bottom bits clear */
                length = ((getrandomuint64() % (filesize-0x800)) & ~((uint64_t)0x3ff)) + 0x400;
                /* generate an offset that will fit the length */
                offset = (getrandomuint64() % (filesize-length)) & ~((uint64_t)0x3ff);
                flags = getrandomuint64();

                command = (flags & 0x01)?NBD_CMD_READ:NBD_CMD_WRITE;

                if (!(flags & 0x0f))
                        command = NBD_CMD_FLAG_FUA | NBD_CMD_WRITE;

                if (!(flags & 0xf0)) {
                        offset = 0;
                        length = 0;
                        command = NBD_CMD_FLUSH;
                }

                *(uint64_t *)(req.handle) = htonll(handle);
                *(uint64_t *)(rep.handle) = htonll(handle);
                req.type = htonl(command);
                req.from = htonll(offset);
                req.len = htonl(length);

                dowrite(writefd, &req, sizeof(req));
                dowrite(writefd, &rep, sizeof(rep));
        }

        req.type = htonl(NBD_CMD_DISC);
        req.from = 0;
        req.len = 0;
        dowrite(writefd, &req, sizeof(req));
        
        return 0;
}