xref: /openbmc/qemu/block/parallels.c (revision 9f2d175d)
1 /*
2  * Block driver for Parallels disk image format
3  *
4  * Copyright (c) 2007 Alex Beregszaszi
5  * Copyright (c) 2015 Denis V. Lunev <den@openvz.org>
6  *
7  * This code was originally based on comparing different disk images created
8  * by Parallels. Currently it is based on opened OpenVZ sources
9  * available at
10  *     http://git.openvz.org/?p=ploop;a=summary
11  *
12  * Permission is hereby granted, free of charge, to any person obtaining a copy
13  * of this software and associated documentation files (the "Software"), to deal
14  * in the Software without restriction, including without limitation the rights
15  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
16  * copies of the Software, and to permit persons to whom the Software is
17  * furnished to do so, subject to the following conditions:
18  *
19  * The above copyright notice and this permission notice shall be included in
20  * all copies or substantial portions of the Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
25  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
27  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
28  * THE SOFTWARE.
29  */
30 
31 #include "qemu/osdep.h"
32 #include "qapi/error.h"
33 #include "block/block_int.h"
34 #include "sysemu/block-backend.h"
35 #include "qemu/module.h"
36 #include "qemu/option.h"
37 #include "qemu/bswap.h"
38 #include "qemu/bitmap.h"
39 #include "migration/blocker.h"
40 #include "parallels.h"
41 
42 /**************************************************************/
43 
44 #define HEADER_MAGIC "WithoutFreeSpace"
45 #define HEADER_MAGIC2 "WithouFreSpacExt"
46 #define HEADER_VERSION 2
47 #define HEADER_INUSE_MAGIC  (0x746F6E59)
48 #define MAX_PARALLELS_IMAGE_FACTOR (1ull << 32)
49 
50 static QEnumLookup prealloc_mode_lookup = {
51     .array = (const char *const[]) {
52         "falloc",
53         "truncate",
54     },
55     .size = PRL_PREALLOC_MODE__MAX
56 };
57 
58 #define PARALLELS_OPT_PREALLOC_MODE     "prealloc-mode"
59 #define PARALLELS_OPT_PREALLOC_SIZE     "prealloc-size"
60 
61 static QemuOptsList parallels_runtime_opts = {
62     .name = "parallels",
63     .head = QTAILQ_HEAD_INITIALIZER(parallels_runtime_opts.head),
64     .desc = {
65         {
66             .name = PARALLELS_OPT_PREALLOC_SIZE,
67             .type = QEMU_OPT_SIZE,
68             .help = "Preallocation size on image expansion",
69             .def_value_str = "128M",
70         },
71         {
72             .name = PARALLELS_OPT_PREALLOC_MODE,
73             .type = QEMU_OPT_STRING,
74             .help = "Preallocation mode on image expansion "
75                     "(allowed values: falloc, truncate)",
76             .def_value_str = "falloc",
77         },
78         { /* end of list */ },
79     },
80 };
81 
82 
83 static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx)
84 {
85     return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier;
86 }
87 
88 static uint32_t bat_entry_off(uint32_t idx)
89 {
90     return sizeof(ParallelsHeader) + sizeof(uint32_t) * idx;
91 }
92 
93 static int64_t seek_to_sector(BDRVParallelsState *s, int64_t sector_num)
94 {
95     uint32_t index, offset;
96 
97     index = sector_num / s->tracks;
98     offset = sector_num % s->tracks;
99 
100     /* not allocated */
101     if ((index >= s->bat_size) || (s->bat_bitmap[index] == 0)) {
102         return -1;
103     }
104     return bat2sect(s, index) + offset;
105 }
106 
107 static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
108         int nb_sectors)
109 {
110     int ret = s->tracks - sector_num % s->tracks;
111     return MIN(nb_sectors, ret);
112 }
113 
114 static int64_t block_status(BDRVParallelsState *s, int64_t sector_num,
115                             int nb_sectors, int *pnum)
116 {
117     int64_t start_off = -2, prev_end_off = -2;
118 
119     *pnum = 0;
120     while (nb_sectors > 0 || start_off == -2) {
121         int64_t offset = seek_to_sector(s, sector_num);
122         int to_end;
123 
124         if (start_off == -2) {
125             start_off = offset;
126             prev_end_off = offset;
127         } else if (offset != prev_end_off) {
128             break;
129         }
130 
131         to_end = cluster_remainder(s, sector_num, nb_sectors);
132         nb_sectors -= to_end;
133         sector_num += to_end;
134         *pnum += to_end;
135 
136         if (offset > 0) {
137             prev_end_off += to_end;
138         }
139     }
140     return start_off;
141 }
142 
143 static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num,
144                                  int nb_sectors, int *pnum)
145 {
146     int ret;
147     BDRVParallelsState *s = bs->opaque;
148     int64_t pos, space, idx, to_allocate, i, len;
149 
150     pos = block_status(s, sector_num, nb_sectors, pnum);
151     if (pos > 0) {
152         return pos;
153     }
154 
155     idx = sector_num / s->tracks;
156     to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
157 
158     /* This function is called only by parallels_co_writev(), which will never
159      * pass a sector_num at or beyond the end of the image (because the block
160      * layer never passes such a sector_num to that function). Therefore, idx
161      * is always below s->bat_size.
162      * block_status() will limit *pnum so that sector_num + *pnum will not
163      * exceed the image end. Therefore, idx + to_allocate cannot exceed
164      * s->bat_size.
165      * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
166      * will always fit into a uint32_t. */
167     assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
168 
169     space = to_allocate * s->tracks;
170     len = bdrv_getlength(bs->file->bs);
171     if (len < 0) {
172         return len;
173     }
174     if (s->data_end + space > (len >> BDRV_SECTOR_BITS)) {
175         space += s->prealloc_size;
176         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
177             ret = bdrv_pwrite_zeroes(bs->file,
178                                      s->data_end << BDRV_SECTOR_BITS,
179                                      space << BDRV_SECTOR_BITS, 0);
180         } else {
181             ret = bdrv_truncate(bs->file,
182                                 (s->data_end + space) << BDRV_SECTOR_BITS,
183                                 PREALLOC_MODE_OFF, NULL);
184         }
185         if (ret < 0) {
186             return ret;
187         }
188     }
189 
190     /* Try to read from backing to fill empty clusters
191      * FIXME: 1. previous write_zeroes may be redundant
192      *        2. most of data we read from backing will be rewritten by
193      *           parallels_co_writev. On aligned-to-cluster write we do not need
194      *           this read at all.
195      *        3. it would be good to combine write of data from backing and new
196      *           data into one write call */
197     if (bs->backing) {
198         int64_t nb_cow_sectors = to_allocate * s->tracks;
199         int64_t nb_cow_bytes = nb_cow_sectors << BDRV_SECTOR_BITS;
200         QEMUIOVector qiov;
201         struct iovec iov = {
202             .iov_len = nb_cow_bytes,
203             .iov_base = qemu_blockalign(bs, nb_cow_bytes)
204         };
205         qemu_iovec_init_external(&qiov, &iov, 1);
206 
207         ret = bdrv_co_readv(bs->backing, idx * s->tracks, nb_cow_sectors,
208                             &qiov);
209         if (ret < 0) {
210             qemu_vfree(iov.iov_base);
211             return ret;
212         }
213 
214         ret = bdrv_co_writev(bs->file, s->data_end, nb_cow_sectors, &qiov);
215         qemu_vfree(iov.iov_base);
216         if (ret < 0) {
217             return ret;
218         }
219     }
220 
221     for (i = 0; i < to_allocate; i++) {
222         s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
223         s->data_end += s->tracks;
224         bitmap_set(s->bat_dirty_bmap,
225                    bat_entry_off(idx + i) / s->bat_dirty_block, 1);
226     }
227 
228     return bat2sect(s, idx) + sector_num % s->tracks;
229 }
230 
231 
232 static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
233 {
234     BDRVParallelsState *s = bs->opaque;
235     unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
236     unsigned long bit;
237 
238     qemu_co_mutex_lock(&s->lock);
239 
240     bit = find_first_bit(s->bat_dirty_bmap, size);
241     while (bit < size) {
242         uint32_t off = bit * s->bat_dirty_block;
243         uint32_t to_write = s->bat_dirty_block;
244         int ret;
245 
246         if (off + to_write > s->header_size) {
247             to_write = s->header_size - off;
248         }
249         ret = bdrv_pwrite(bs->file, off, (uint8_t *)s->header + off,
250                           to_write);
251         if (ret < 0) {
252             qemu_co_mutex_unlock(&s->lock);
253             return ret;
254         }
255         bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
256     }
257     bitmap_zero(s->bat_dirty_bmap, size);
258 
259     qemu_co_mutex_unlock(&s->lock);
260     return 0;
261 }
262 
263 
264 static int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
265                                                   bool want_zero,
266                                                   int64_t offset,
267                                                   int64_t bytes,
268                                                   int64_t *pnum,
269                                                   int64_t *map,
270                                                   BlockDriverState **file)
271 {
272     BDRVParallelsState *s = bs->opaque;
273     int count;
274 
275     assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
276     qemu_co_mutex_lock(&s->lock);
277     offset = block_status(s, offset >> BDRV_SECTOR_BITS,
278                           bytes >> BDRV_SECTOR_BITS, &count);
279     qemu_co_mutex_unlock(&s->lock);
280 
281     *pnum = count * BDRV_SECTOR_SIZE;
282     if (offset < 0) {
283         return 0;
284     }
285 
286     *map = offset * BDRV_SECTOR_SIZE;
287     *file = bs->file->bs;
288     return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
289 }
290 
291 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
292         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
293 {
294     BDRVParallelsState *s = bs->opaque;
295     uint64_t bytes_done = 0;
296     QEMUIOVector hd_qiov;
297     int ret = 0;
298 
299     qemu_iovec_init(&hd_qiov, qiov->niov);
300 
301     while (nb_sectors > 0) {
302         int64_t position;
303         int n, nbytes;
304 
305         qemu_co_mutex_lock(&s->lock);
306         position = allocate_clusters(bs, sector_num, nb_sectors, &n);
307         qemu_co_mutex_unlock(&s->lock);
308         if (position < 0) {
309             ret = (int)position;
310             break;
311         }
312 
313         nbytes = n << BDRV_SECTOR_BITS;
314 
315         qemu_iovec_reset(&hd_qiov);
316         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
317 
318         ret = bdrv_co_writev(bs->file, position, n, &hd_qiov);
319         if (ret < 0) {
320             break;
321         }
322 
323         nb_sectors -= n;
324         sector_num += n;
325         bytes_done += nbytes;
326     }
327 
328     qemu_iovec_destroy(&hd_qiov);
329     return ret;
330 }
331 
332 static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
333         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
334 {
335     BDRVParallelsState *s = bs->opaque;
336     uint64_t bytes_done = 0;
337     QEMUIOVector hd_qiov;
338     int ret = 0;
339 
340     qemu_iovec_init(&hd_qiov, qiov->niov);
341 
342     while (nb_sectors > 0) {
343         int64_t position;
344         int n, nbytes;
345 
346         qemu_co_mutex_lock(&s->lock);
347         position = block_status(s, sector_num, nb_sectors, &n);
348         qemu_co_mutex_unlock(&s->lock);
349 
350         nbytes = n << BDRV_SECTOR_BITS;
351 
352         qemu_iovec_reset(&hd_qiov);
353         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
354 
355         if (position < 0) {
356             if (bs->backing) {
357                 ret = bdrv_co_readv(bs->backing, sector_num, n, &hd_qiov);
358                 if (ret < 0) {
359                     break;
360                 }
361             } else {
362                 qemu_iovec_memset(&hd_qiov, 0, 0, nbytes);
363             }
364         } else {
365             ret = bdrv_co_readv(bs->file, position, n, &hd_qiov);
366             if (ret < 0) {
367                 break;
368             }
369         }
370 
371         nb_sectors -= n;
372         sector_num += n;
373         bytes_done += nbytes;
374     }
375 
376     qemu_iovec_destroy(&hd_qiov);
377     return ret;
378 }
379 
380 
381 static int coroutine_fn parallels_co_check(BlockDriverState *bs,
382                                            BdrvCheckResult *res,
383                                            BdrvCheckMode fix)
384 {
385     BDRVParallelsState *s = bs->opaque;
386     int64_t size, prev_off, high_off;
387     int ret;
388     uint32_t i;
389     bool flush_bat = false;
390     int cluster_size = s->tracks << BDRV_SECTOR_BITS;
391 
392     size = bdrv_getlength(bs->file->bs);
393     if (size < 0) {
394         res->check_errors++;
395         return size;
396     }
397 
398     qemu_co_mutex_lock(&s->lock);
399     if (s->header_unclean) {
400         fprintf(stderr, "%s image was not closed correctly\n",
401                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
402         res->corruptions++;
403         if (fix & BDRV_FIX_ERRORS) {
404             /* parallels_close will do the job right */
405             res->corruptions_fixed++;
406             s->header_unclean = false;
407         }
408     }
409 
410     res->bfi.total_clusters = s->bat_size;
411     res->bfi.compressed_clusters = 0; /* compression is not supported */
412 
413     high_off = 0;
414     prev_off = 0;
415     for (i = 0; i < s->bat_size; i++) {
416         int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
417         if (off == 0) {
418             prev_off = 0;
419             continue;
420         }
421 
422         /* cluster outside the image */
423         if (off > size) {
424             fprintf(stderr, "%s cluster %u is outside image\n",
425                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
426             res->corruptions++;
427             if (fix & BDRV_FIX_ERRORS) {
428                 prev_off = 0;
429                 s->bat_bitmap[i] = 0;
430                 res->corruptions_fixed++;
431                 flush_bat = true;
432                 continue;
433             }
434         }
435 
436         res->bfi.allocated_clusters++;
437         if (off > high_off) {
438             high_off = off;
439         }
440 
441         if (prev_off != 0 && (prev_off + cluster_size) != off) {
442             res->bfi.fragmented_clusters++;
443         }
444         prev_off = off;
445     }
446 
447     ret = 0;
448     if (flush_bat) {
449         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
450         if (ret < 0) {
451             res->check_errors++;
452             goto out;
453         }
454     }
455 
456     res->image_end_offset = high_off + cluster_size;
457     if (size > res->image_end_offset) {
458         int64_t count;
459         count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
460         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
461                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
462                 size - res->image_end_offset);
463         res->leaks += count;
464         if (fix & BDRV_FIX_LEAKS) {
465             Error *local_err = NULL;
466             ret = bdrv_truncate(bs->file, res->image_end_offset,
467                                 PREALLOC_MODE_OFF, &local_err);
468             if (ret < 0) {
469                 error_report_err(local_err);
470                 res->check_errors++;
471                 goto out;
472             }
473             res->leaks_fixed += count;
474         }
475     }
476 
477 out:
478     qemu_co_mutex_unlock(&s->lock);
479     return ret;
480 }
481 
482 
483 static int coroutine_fn parallels_co_create_opts(const char *filename,
484                                                  QemuOpts *opts,
485                                                  Error **errp)
486 {
487     int64_t total_size, cl_size;
488     uint8_t tmp[BDRV_SECTOR_SIZE];
489     Error *local_err = NULL;
490     BlockBackend *file;
491     uint32_t bat_entries, bat_sectors;
492     ParallelsHeader header;
493     int ret;
494 
495     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
496                           BDRV_SECTOR_SIZE);
497     cl_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
498                           DEFAULT_CLUSTER_SIZE), BDRV_SECTOR_SIZE);
499     if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
500         error_propagate(errp, local_err);
501         return -E2BIG;
502     }
503 
504     ret = bdrv_create_file(filename, opts, &local_err);
505     if (ret < 0) {
506         error_propagate(errp, local_err);
507         return ret;
508     }
509 
510     file = blk_new_open(filename, NULL, NULL,
511                         BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
512                         &local_err);
513     if (file == NULL) {
514         error_propagate(errp, local_err);
515         return -EIO;
516     }
517 
518     blk_set_allow_write_beyond_eof(file, true);
519 
520     ret = blk_truncate(file, 0, PREALLOC_MODE_OFF, errp);
521     if (ret < 0) {
522         goto exit;
523     }
524 
525     bat_entries = DIV_ROUND_UP(total_size, cl_size);
526     bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
527     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
528 
529     memset(&header, 0, sizeof(header));
530     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
531     header.version = cpu_to_le32(HEADER_VERSION);
532     /* don't care much about geometry, it is not used on image level */
533     header.heads = cpu_to_le32(HEADS_NUMBER);
534     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE
535                                    / HEADS_NUMBER / SEC_IN_CYL);
536     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
537     header.bat_entries = cpu_to_le32(bat_entries);
538     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
539     header.data_off = cpu_to_le32(bat_sectors);
540 
541     /* write all the data */
542     memset(tmp, 0, sizeof(tmp));
543     memcpy(tmp, &header, sizeof(header));
544 
545     ret = blk_pwrite(file, 0, tmp, BDRV_SECTOR_SIZE, 0);
546     if (ret < 0) {
547         goto exit;
548     }
549     ret = blk_pwrite_zeroes(file, BDRV_SECTOR_SIZE,
550                             (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
551     if (ret < 0) {
552         goto exit;
553     }
554     ret = 0;
555 
556 done:
557     blk_unref(file);
558     return ret;
559 
560 exit:
561     error_setg_errno(errp, -ret, "Failed to create Parallels image");
562     goto done;
563 }
564 
565 
566 static int parallels_probe(const uint8_t *buf, int buf_size,
567                            const char *filename)
568 {
569     const ParallelsHeader *ph = (const void *)buf;
570 
571     if (buf_size < sizeof(ParallelsHeader)) {
572         return 0;
573     }
574 
575     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
576            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
577            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
578         return 100;
579     }
580 
581     return 0;
582 }
583 
584 static int parallels_update_header(BlockDriverState *bs)
585 {
586     BDRVParallelsState *s = bs->opaque;
587     unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
588                         sizeof(ParallelsHeader));
589 
590     if (size > s->header_size) {
591         size = s->header_size;
592     }
593     return bdrv_pwrite_sync(bs->file, 0, s->header, size);
594 }
595 
596 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
597                           Error **errp)
598 {
599     BDRVParallelsState *s = bs->opaque;
600     ParallelsHeader ph;
601     int ret, size, i;
602     QemuOpts *opts = NULL;
603     Error *local_err = NULL;
604     char *buf;
605 
606     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
607                                false, errp);
608     if (!bs->file) {
609         return -EINVAL;
610     }
611 
612     ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
613     if (ret < 0) {
614         goto fail;
615     }
616 
617     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
618 
619     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
620         goto fail_format;
621     }
622     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
623         s->off_multiplier = 1;
624         bs->total_sectors = 0xffffffff & bs->total_sectors;
625     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
626         s->off_multiplier = le32_to_cpu(ph.tracks);
627     } else {
628         goto fail_format;
629     }
630 
631     s->tracks = le32_to_cpu(ph.tracks);
632     if (s->tracks == 0) {
633         error_setg(errp, "Invalid image: Zero sectors per track");
634         ret = -EINVAL;
635         goto fail;
636     }
637     if (s->tracks > INT32_MAX/513) {
638         error_setg(errp, "Invalid image: Too big cluster");
639         ret = -EFBIG;
640         goto fail;
641     }
642 
643     s->bat_size = le32_to_cpu(ph.bat_entries);
644     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
645         error_setg(errp, "Catalog too large");
646         ret = -EFBIG;
647         goto fail;
648     }
649 
650     size = bat_entry_off(s->bat_size);
651     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
652     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
653     if (s->header == NULL) {
654         ret = -ENOMEM;
655         goto fail;
656     }
657     s->data_end = le32_to_cpu(ph.data_off);
658     if (s->data_end == 0) {
659         s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
660     }
661     if (s->data_end < s->header_size) {
662         /* there is not enough unused space to fit to block align between BAT
663            and actual data. We can't avoid read-modify-write... */
664         s->header_size = size;
665     }
666 
667     ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
668     if (ret < 0) {
669         goto fail;
670     }
671     s->bat_bitmap = (uint32_t *)(s->header + 1);
672 
673     for (i = 0; i < s->bat_size; i++) {
674         int64_t off = bat2sect(s, i);
675         if (off >= s->data_end) {
676             s->data_end = off + s->tracks;
677         }
678     }
679 
680     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
681         /* Image was not closed correctly. The check is mandatory */
682         s->header_unclean = true;
683         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
684             error_setg(errp, "parallels: Image was not closed correctly; "
685                        "cannot be opened read/write");
686             ret = -EACCES;
687             goto fail;
688         }
689     }
690 
691     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, &local_err);
692     if (local_err != NULL) {
693         goto fail_options;
694     }
695 
696     qemu_opts_absorb_qdict(opts, options, &local_err);
697     if (local_err != NULL) {
698         goto fail_options;
699     }
700 
701     s->prealloc_size =
702         qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
703     s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
704     buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
705     s->prealloc_mode = qapi_enum_parse(&prealloc_mode_lookup, buf,
706                                        PRL_PREALLOC_MODE_FALLOCATE,
707                                        &local_err);
708     g_free(buf);
709     if (local_err != NULL) {
710         goto fail_options;
711     }
712 
713     if (!bdrv_has_zero_init(bs->file->bs)) {
714         s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
715     }
716 
717     if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
718         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
719         ret = parallels_update_header(bs);
720         if (ret < 0) {
721             goto fail;
722         }
723     }
724 
725     s->bat_dirty_block = 4 * getpagesize();
726     s->bat_dirty_bmap =
727         bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
728 
729     /* Disable migration until bdrv_invalidate_cache method is added */
730     error_setg(&s->migration_blocker, "The Parallels format used by node '%s' "
731                "does not support live migration",
732                bdrv_get_device_or_node_name(bs));
733     ret = migrate_add_blocker(s->migration_blocker, &local_err);
734     if (local_err) {
735         error_propagate(errp, local_err);
736         error_free(s->migration_blocker);
737         goto fail;
738     }
739     qemu_co_mutex_init(&s->lock);
740     return 0;
741 
742 fail_format:
743     error_setg(errp, "Image not in Parallels format");
744     ret = -EINVAL;
745 fail:
746     qemu_vfree(s->header);
747     return ret;
748 
749 fail_options:
750     error_propagate(errp, local_err);
751     ret = -EINVAL;
752     goto fail;
753 }
754 
755 
756 static void parallels_close(BlockDriverState *bs)
757 {
758     BDRVParallelsState *s = bs->opaque;
759 
760     if ((bs->open_flags & BDRV_O_RDWR) && !(bs->open_flags & BDRV_O_INACTIVE)) {
761         s->header->inuse = 0;
762         parallels_update_header(bs);
763         bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS,
764                       PREALLOC_MODE_OFF, NULL);
765     }
766 
767     g_free(s->bat_dirty_bmap);
768     qemu_vfree(s->header);
769 
770     migrate_del_blocker(s->migration_blocker);
771     error_free(s->migration_blocker);
772 }
773 
774 static QemuOptsList parallels_create_opts = {
775     .name = "parallels-create-opts",
776     .head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
777     .desc = {
778         {
779             .name = BLOCK_OPT_SIZE,
780             .type = QEMU_OPT_SIZE,
781             .help = "Virtual disk size",
782         },
783         {
784             .name = BLOCK_OPT_CLUSTER_SIZE,
785             .type = QEMU_OPT_SIZE,
786             .help = "Parallels image cluster size",
787             .def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
788         },
789         { /* end of list */ }
790     }
791 };
792 
793 static BlockDriver bdrv_parallels = {
794     .format_name	= "parallels",
795     .instance_size	= sizeof(BDRVParallelsState),
796     .bdrv_probe		= parallels_probe,
797     .bdrv_open		= parallels_open,
798     .bdrv_close		= parallels_close,
799     .bdrv_child_perm          = bdrv_format_default_perms,
800     .bdrv_co_block_status     = parallels_co_block_status,
801     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
802     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
803     .bdrv_co_readv  = parallels_co_readv,
804     .bdrv_co_writev = parallels_co_writev,
805     .supports_backing = true,
806     .bdrv_co_create_opts = parallels_co_create_opts,
807     .bdrv_co_check  = parallels_co_check,
808     .create_opts    = &parallels_create_opts,
809 };
810 
811 static void bdrv_parallels_init(void)
812 {
813     bdrv_register(&bdrv_parallels);
814 }
815 
816 block_init(bdrv_parallels_init);
817