qcow.c revision 272773
1/*- 2 * Copyright (c) 2014 Marcel Moolenaar 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: stable/10/usr.bin/mkimg/qcow.c 272773 2014-10-08 22:01:35Z marcel $"); 29 30#include <sys/types.h> 31#include <sys/endian.h> 32#include <sys/errno.h> 33#include <stdint.h> 34#include <stdio.h> 35#include <stdlib.h> 36#include <string.h> 37#include <unistd.h> 38 39#include "image.h" 40#include "format.h" 41#include "mkimg.h" 42 43/* Default cluster sizes. */ 44#define QCOW1_CLSTR_LOG2SZ 12 /* 4KB */ 45#define QCOW2_CLSTR_LOG2SZ 16 /* 64KB */ 46 47/* Flag bits in cluster offsets */ 48#define QCOW_CLSTR_COMPRESSED (1ULL << 62) 49#define QCOW_CLSTR_COPIED (1ULL << 63) 50 51struct qcow_header { 52 uint32_t magic; 53#define QCOW_MAGIC 0x514649fb 54 uint32_t version; 55#define QCOW_VERSION_1 1 56#define QCOW_VERSION_2 2 57 uint64_t path_offset; 58 uint32_t path_length; 59 uint32_t clstr_log2sz; /* v2 only */ 60 uint64_t disk_size; 61 union { 62 struct { 63 uint8_t clstr_log2sz; 64 uint8_t l2_log2sz; 65 uint16_t _pad; 66 uint32_t encryption; 67 uint64_t l1_offset; 68 } v1; 69 struct { 70 uint32_t encryption; 71 uint32_t l1_entries; 72 uint64_t l1_offset; 73 uint64_t refcnt_offset; 74 uint32_t refcnt_entries; 75 uint32_t snapshot_count; 76 uint64_t snapshot_offset; 77 } v2; 78 } u; 79}; 80 81static u_int clstr_log2sz; 82 83static uint64_t 84round_clstr(uint64_t ofs) 85{ 86 uint64_t clstrsz; 87 88 clstrsz = 1UL << clstr_log2sz; 89 return ((ofs + clstrsz - 1) & ~(clstrsz - 1)); 90} 91 92static int 93qcow_resize(lba_t imgsz, u_int version) 94{ 95 uint64_t imagesz; 96 97 switch (version) { 98 case QCOW_VERSION_1: 99 clstr_log2sz = QCOW1_CLSTR_LOG2SZ; 100 break; 101 case QCOW_VERSION_2: 102 clstr_log2sz = QCOW2_CLSTR_LOG2SZ; 103 break; 104 default: 105 return (EDOOFUS); 106 } 107 108 imagesz = round_clstr(imgsz * secsz); 109 110 if (verbose) 111 fprintf(stderr, "QCOW: image size = %ju, cluster size = %u\n", 112 (uintmax_t)imagesz, (u_int)(1U << clstr_log2sz)); 113 114 return (image_set_size(imagesz / secsz)); 115} 116 117static int 118qcow1_resize(lba_t imgsz) 119{ 120 121 return (qcow_resize(imgsz, QCOW_VERSION_1)); 122} 123 124static int 125qcow2_resize(lba_t imgsz) 126{ 127 128 return (qcow_resize(imgsz, QCOW_VERSION_2)); 129} 130 131static int 132qcow_write(int fd, u_int version) 133{ 134 struct qcow_header *hdr; 135 uint64_t *l1tbl, *l2tbl, *rctbl; 136 uint16_t *rcblk; 137 uint64_t clstr_imgsz, clstr_l2tbls, clstr_l1tblsz; 138 uint64_t clstr_rcblks, clstr_rctblsz; 139 uint64_t n, imagesz, nclstrs, ofs, ofsflags; 140 lba_t blk, blkofs, blk_imgsz; 141 u_int l1clno, l2clno, rcclno; 142 u_int blk_clstrsz; 143 u_int clstrsz, l1idx, l2idx; 144 int error; 145 146 if (clstr_log2sz == 0) 147 return (EDOOFUS); 148 149 clstrsz = 1U << clstr_log2sz; 150 blk_clstrsz = clstrsz / secsz; 151 blk_imgsz = image_get_size(); 152 imagesz = blk_imgsz * secsz; 153 clstr_imgsz = imagesz >> clstr_log2sz; 154 clstr_l2tbls = round_clstr(clstr_imgsz * 8) >> clstr_log2sz; 155 clstr_l1tblsz = round_clstr(clstr_l2tbls * 8) >> clstr_log2sz; 156 nclstrs = clstr_imgsz + clstr_l2tbls + clstr_l1tblsz + 1; 157 clstr_rcblks = clstr_rctblsz = 0; 158 do { 159 n = clstr_rcblks + clstr_rctblsz; 160 clstr_rcblks = round_clstr((nclstrs + n) * 2) >> clstr_log2sz; 161 clstr_rctblsz = round_clstr(clstr_rcblks * 8) >> clstr_log2sz; 162 } while (n < (clstr_rcblks + clstr_rctblsz)); 163 164 /* 165 * We got all the sizes in clusters. Start the layout. 166 * 0 - header 167 * 1 - L1 table 168 * 2 - RC table (v2 only) 169 * 3 - L2 tables 170 * 4 - RC block (v2 only) 171 * 5 - data 172 */ 173 174 l1clno = 1; 175 rcclno = 0; 176 rctbl = l2tbl = l1tbl = NULL; 177 rcblk = NULL; 178 179 hdr = calloc(1, clstrsz); 180 if (hdr == NULL) 181 return (errno); 182 183 be32enc(&hdr->magic, QCOW_MAGIC); 184 be32enc(&hdr->version, version); 185 be64enc(&hdr->disk_size, imagesz); 186 switch (version) { 187 case QCOW_VERSION_1: 188 ofsflags = 0; 189 l2clno = l1clno + clstr_l1tblsz; 190 hdr->u.v1.clstr_log2sz = clstr_log2sz; 191 hdr->u.v1.l2_log2sz = clstr_log2sz - 3; 192 be64enc(&hdr->u.v1.l1_offset, clstrsz * l1clno); 193 break; 194 case QCOW_VERSION_2: 195 ofsflags = QCOW_CLSTR_COPIED; 196 rcclno = l1clno + clstr_l1tblsz; 197 l2clno = rcclno + clstr_rctblsz; 198 be32enc(&hdr->clstr_log2sz, clstr_log2sz); 199 be32enc(&hdr->u.v2.l1_entries, clstr_l2tbls); 200 be64enc(&hdr->u.v2.l1_offset, clstrsz * l1clno); 201 be64enc(&hdr->u.v2.refcnt_offset, clstrsz * rcclno); 202 be32enc(&hdr->u.v2.refcnt_entries, clstr_rcblks); 203 break; 204 default: 205 return (EDOOFUS); 206 } 207 208 if (sparse_write(fd, hdr, clstrsz) < 0) { 209 error = errno; 210 goto out; 211 } 212 213 free(hdr); 214 hdr = NULL; 215 216 ofs = clstrsz * l2clno; 217 nclstrs = 1 + clstr_l1tblsz + clstr_rctblsz; 218 219 l1tbl = calloc(1, clstrsz * clstr_l1tblsz); 220 if (l1tbl == NULL) { 221 error = ENOMEM; 222 goto out; 223 } 224 225 for (n = 0; n < clstr_imgsz; n++) { 226 blk = n * blk_clstrsz; 227 if (image_data(blk, blk_clstrsz)) { 228 nclstrs++; 229 l1idx = n >> (clstr_log2sz - 3); 230 if (l1tbl[l1idx] == 0) { 231 be64enc(l1tbl + l1idx, ofs + ofsflags); 232 ofs += clstrsz; 233 nclstrs++; 234 } 235 } 236 } 237 238 if (sparse_write(fd, l1tbl, clstrsz * clstr_l1tblsz) < 0) { 239 error = errno; 240 goto out; 241 } 242 243 clstr_rcblks = 0; 244 do { 245 n = clstr_rcblks; 246 clstr_rcblks = round_clstr((nclstrs + n) * 2) >> clstr_log2sz; 247 } while (n < clstr_rcblks); 248 249 if (rcclno > 0) { 250 rctbl = calloc(1, clstrsz * clstr_rctblsz); 251 if (rctbl == NULL) { 252 error = ENOMEM; 253 goto out; 254 } 255 for (n = 0; n < clstr_rcblks; n++) { 256 be64enc(rctbl + n, ofs); 257 ofs += clstrsz; 258 nclstrs++; 259 } 260 if (sparse_write(fd, rctbl, clstrsz * clstr_rctblsz) < 0) { 261 error = errno; 262 goto out; 263 } 264 free(rctbl); 265 rctbl = NULL; 266 } 267 268 l2tbl = malloc(clstrsz); 269 if (l2tbl == NULL) { 270 error = ENOMEM; 271 goto out; 272 } 273 274 for (l1idx = 0; l1idx < clstr_l2tbls; l1idx++) { 275 if (l1tbl[l1idx] == 0) 276 continue; 277 memset(l2tbl, 0, clstrsz); 278 blkofs = (lba_t)l1idx * blk_clstrsz * (clstrsz >> 3); 279 for (l2idx = 0; l2idx < (clstrsz >> 3); l2idx++) { 280 blk = blkofs + (lba_t)l2idx * blk_clstrsz; 281 if (blk >= blk_imgsz) 282 break; 283 if (image_data(blk, blk_clstrsz)) { 284 be64enc(l2tbl + l2idx, ofs + ofsflags); 285 ofs += clstrsz; 286 } 287 } 288 if (sparse_write(fd, l2tbl, clstrsz) < 0) { 289 error = errno; 290 goto out; 291 } 292 } 293 294 free(l2tbl); 295 l2tbl = NULL; 296 free(l1tbl); 297 l1tbl = NULL; 298 299 if (rcclno > 0) { 300 rcblk = calloc(1, clstrsz * clstr_rcblks); 301 if (rcblk == NULL) { 302 error = ENOMEM; 303 goto out; 304 } 305 for (n = 0; n < nclstrs; n++) 306 be16enc(rcblk + n, 1); 307 if (sparse_write(fd, rcblk, clstrsz * clstr_rcblks) < 0) { 308 error = errno; 309 goto out; 310 } 311 free(rcblk); 312 rcblk = NULL; 313 } 314 315 error = 0; 316 for (n = 0; n < clstr_imgsz; n++) { 317 blk = n * blk_clstrsz; 318 if (image_data(blk, blk_clstrsz)) { 319 error = image_copyout_region(fd, blk, blk_clstrsz); 320 if (error) 321 break; 322 } 323 } 324 if (!error) 325 error = image_copyout_done(fd); 326 327 out: 328 if (rcblk != NULL) 329 free(rcblk); 330 if (l2tbl != NULL) 331 free(l2tbl); 332 if (rctbl != NULL) 333 free(rctbl); 334 if (l1tbl != NULL) 335 free(l1tbl); 336 if (hdr != NULL) 337 free(hdr); 338 return (error); 339} 340 341static int 342qcow1_write(int fd) 343{ 344 345 return (qcow_write(fd, QCOW_VERSION_1)); 346} 347 348static int 349qcow2_write(int fd) 350{ 351 352 return (qcow_write(fd, QCOW_VERSION_2)); 353} 354 355static struct mkimg_format qcow1_format = { 356 .name = "qcow", 357 .description = "QEMU Copy-On-Write, version 1", 358 .resize = qcow1_resize, 359 .write = qcow1_write, 360}; 361FORMAT_DEFINE(qcow1_format); 362 363static struct mkimg_format qcow2_format = { 364 .name = "qcow2", 365 .description = "QEMU Copy-On-Write, version 2", 366 .resize = qcow2_resize, 367 .write = qcow2_write, 368}; 369FORMAT_DEFINE(qcow2_format); 370