freebsd-skq/usr.bin/mkimg/qcow.c
Marcel Moolenaar e187064261 Finish QCOW version 2 and stop making it conditional.
We have a different ordering for the RC block(s) and L2 tables.
This is expected to be a non-issue, because everything is found
through file offsets in the corresponding RC table and L1 table.
Files that grow organically have RC blocks and L2 tables scattered
all over the place anyway.

The reason for the difference is that mkimg needs to be able to
write to a pipe. We can't seek forward and backward to fill in
the bits in non-sequential order.
2014-09-24 22:45:03 +00:00

370 lines
8.3 KiB
C

/*-
* Copyright (c) 2014 Marcel Moolenaar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/endian.h>
#include <sys/errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "image.h"
#include "format.h"
#include "mkimg.h"
/* Default cluster sizes. */
#define QCOW1_CLSTR_LOG2SZ 12 /* 4KB */
#define QCOW2_CLSTR_LOG2SZ 16 /* 64KB */
/* Flag bits in cluster offsets */
#define QCOW_CLSTR_COMPRESSED (1ULL << 62)
#define QCOW_CLSTR_COPIED (1ULL << 63)
struct qcow_header {
uint32_t magic;
#define QCOW_MAGIC 0x514649fb
uint32_t version;
#define QCOW_VERSION_1 1
#define QCOW_VERSION_2 2
uint64_t path_offset;
uint32_t path_length;
uint32_t clstr_log2sz; /* v2 only */
uint64_t disk_size;
union {
struct {
uint8_t clstr_log2sz;
uint8_t l2_log2sz;
uint16_t _pad;
uint32_t encryption;
uint64_t l1_offset;
} v1;
struct {
uint32_t encryption;
uint32_t l1_entries;
uint64_t l1_offset;
uint64_t refcnt_offset;
uint32_t refcnt_entries;
uint32_t snapshot_count;
uint64_t snapshot_offset;
} v2;
} u;
};
static u_int clstr_log2sz;
static uint64_t
round_clstr(uint64_t ofs)
{
uint64_t clstrsz;
clstrsz = 1UL << clstr_log2sz;
return ((ofs + clstrsz - 1) & ~(clstrsz - 1));
}
static int
qcow_resize(lba_t imgsz, u_int version)
{
uint64_t imagesz;
switch (version) {
case QCOW_VERSION_1:
clstr_log2sz = QCOW1_CLSTR_LOG2SZ;
break;
case QCOW_VERSION_2:
clstr_log2sz = QCOW2_CLSTR_LOG2SZ;
break;
default:
return (EDOOFUS);
}
imagesz = round_clstr(imgsz * secsz);
if (verbose)
fprintf(stderr, "QCOW: image size = %ju, cluster size = %u\n",
(uintmax_t)imagesz, (u_int)(1U << clstr_log2sz));
return (image_set_size(imagesz / secsz));
}
static int
qcow1_resize(lba_t imgsz)
{
return (qcow_resize(imgsz, QCOW_VERSION_1));
}
static int
qcow2_resize(lba_t imgsz)
{
return (qcow_resize(imgsz, QCOW_VERSION_2));
}
static int
qcow_write(int fd, u_int version)
{
struct qcow_header *hdr;
uint64_t *l1tbl, *l2tbl, *rctbl;
uint16_t *rcblk;
uint64_t clstr_imgsz, clstr_l2tbls, clstr_l1tblsz;
uint64_t clstr_rcblks, clstr_rctblsz;
uint64_t n, imagesz, nclstrs, ofs, ofsflags;
lba_t blk, blkofs, blk_imgsz;
u_int l1clno, l2clno, rcclno;
u_int blk_clstrsz;
u_int clstrsz, l1idx, l2idx;
int error;
if (clstr_log2sz == 0)
return (EDOOFUS);
clstrsz = 1U << clstr_log2sz;
blk_clstrsz = clstrsz / secsz;
blk_imgsz = image_get_size();
imagesz = blk_imgsz * secsz;
clstr_imgsz = imagesz >> clstr_log2sz;
clstr_l2tbls = round_clstr(clstr_imgsz * 8) >> clstr_log2sz;
clstr_l1tblsz = round_clstr(clstr_l2tbls * 8) >> clstr_log2sz;
nclstrs = clstr_imgsz + clstr_l2tbls + clstr_l1tblsz + 1;
clstr_rcblks = clstr_rctblsz = 0;
do {
n = clstr_rcblks + clstr_rctblsz;
clstr_rcblks = round_clstr((nclstrs + n) * 2) >> clstr_log2sz;
clstr_rctblsz = round_clstr(clstr_rcblks * 8) >> clstr_log2sz;
} while (n < (clstr_rcblks + clstr_rctblsz));
/*
* We got all the sizes in clusters. Start the layout.
* 0 - header
* 1 - L1 table
* 2 - RC table (v2 only)
* 3 - L2 tables
* 4 - RC block (v2 only)
* 5 - data
*/
l1clno = 1;
rcclno = 0;
rctbl = l2tbl = l1tbl = NULL;
rcblk = NULL;
hdr = calloc(1, clstrsz);
if (hdr == NULL)
return (errno);
be32enc(&hdr->magic, QCOW_MAGIC);
be32enc(&hdr->version, version);
be64enc(&hdr->disk_size, imagesz);
switch (version) {
case QCOW_VERSION_1:
ofsflags = 0;
l2clno = l1clno + clstr_l1tblsz;
hdr->u.v1.clstr_log2sz = clstr_log2sz;
hdr->u.v1.l2_log2sz = clstr_log2sz - 3;
be64enc(&hdr->u.v1.l1_offset, clstrsz * l1clno);
break;
case QCOW_VERSION_2:
ofsflags = QCOW_CLSTR_COPIED;
rcclno = l1clno + clstr_l1tblsz;
l2clno = rcclno + clstr_rctblsz;
be32enc(&hdr->clstr_log2sz, clstr_log2sz);
be32enc(&hdr->u.v2.l1_entries, clstr_l2tbls);
be64enc(&hdr->u.v2.l1_offset, clstrsz * l1clno);
be64enc(&hdr->u.v2.refcnt_offset, clstrsz * rcclno);
be32enc(&hdr->u.v2.refcnt_entries, clstr_rcblks);
break;
default:
return (EDOOFUS);
}
if (sparse_write(fd, hdr, clstrsz) < 0) {
error = errno;
goto out;
}
free(hdr);
hdr = NULL;
ofs = clstrsz * l2clno;
nclstrs = 1 + clstr_l1tblsz + clstr_rctblsz;
l1tbl = calloc(1, clstrsz * clstr_l1tblsz);
if (l1tbl == NULL) {
error = ENOMEM;
goto out;
}
for (n = 0; n < clstr_imgsz; n++) {
blk = n * blk_clstrsz;
if (image_data(blk, blk_clstrsz)) {
nclstrs++;
l1idx = n >> (clstr_log2sz - 3);
if (l1tbl[l1idx] == 0) {
be64enc(l1tbl + l1idx, ofs + ofsflags);
ofs += clstrsz;
nclstrs++;
}
}
}
if (sparse_write(fd, l1tbl, clstrsz * clstr_l1tblsz) < 0) {
error = errno;
goto out;
}
clstr_rcblks = 0;
do {
n = clstr_rcblks;
clstr_rcblks = round_clstr((nclstrs + n) * 2) >> clstr_log2sz;
} while (n < clstr_rcblks);
if (rcclno > 0) {
rctbl = calloc(1, clstrsz * clstr_rctblsz);
if (rctbl == NULL) {
error = ENOMEM;
goto out;
}
for (n = 0; n < clstr_rcblks; n++) {
be64enc(rctbl + n, ofs);
ofs += clstrsz;
nclstrs++;
}
if (sparse_write(fd, rctbl, clstrsz * clstr_rctblsz) < 0) {
error = errno;
goto out;
}
free(rctbl);
rctbl = NULL;
}
l2tbl = malloc(clstrsz);
if (l2tbl == NULL) {
error = ENOMEM;
goto out;
}
for (l1idx = 0; l1idx < clstr_l2tbls; l1idx++) {
if (l1tbl[l1idx] == 0)
continue;
memset(l2tbl, 0, clstrsz);
blkofs = (lba_t)l1idx * blk_clstrsz * (clstrsz >> 3);
for (l2idx = 0; l2idx < (clstrsz >> 3); l2idx++) {
blk = blkofs + (lba_t)l2idx * blk_clstrsz;
if (blk >= blk_imgsz)
break;
if (image_data(blk, blk_clstrsz)) {
be64enc(l2tbl + l2idx, ofs + ofsflags);
ofs += clstrsz;
}
}
if (sparse_write(fd, l2tbl, clstrsz) < 0) {
error = errno;
goto out;
}
}
free(l2tbl);
l2tbl = NULL;
free(l1tbl);
l1tbl = NULL;
if (rcclno > 0) {
rcblk = calloc(1, clstrsz * clstr_rcblks);
if (rcblk == NULL) {
error = ENOMEM;
goto out;
}
for (n = 0; n < nclstrs; n++)
be16enc(rcblk + n, 1);
if (sparse_write(fd, rcblk, clstrsz * clstr_rcblks) < 0) {
error = errno;
goto out;
}
free(rcblk);
rcblk = NULL;
}
error = 0;
for (n = 0; n < clstr_imgsz; n++) {
blk = n * blk_clstrsz;
if (image_data(blk, blk_clstrsz)) {
error = image_copyout_region(fd, blk, blk_clstrsz);
if (error)
break;
}
}
if (!error)
error = image_copyout_done(fd);
out:
if (rcblk != NULL)
free(rcblk);
if (l2tbl != NULL)
free(l2tbl);
if (rctbl != NULL)
free(rctbl);
if (l1tbl != NULL)
free(l1tbl);
if (hdr != NULL)
free(hdr);
return (error);
}
static int
qcow1_write(int fd)
{
return (qcow_write(fd, QCOW_VERSION_1));
}
static int
qcow2_write(int fd)
{
return (qcow_write(fd, QCOW_VERSION_2));
}
static struct mkimg_format qcow1_format = {
.name = "qcow",
.description = "QEMU Copy-On-Write, version 1",
.resize = qcow1_resize,
.write = qcow1_write,
};
FORMAT_DEFINE(qcow1_format);
static struct mkimg_format qcow2_format = {
.name = "qcow2",
.description = "QEMU Copy-On-Write, version 2",
.resize = qcow2_resize,
.write = qcow2_write,
};
FORMAT_DEFINE(qcow2_format);