xref: /openbmc/qemu/block/parallels.c (revision f76b348e)
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 "block/qdict.h"
35 #include "sysemu/block-backend.h"
36 #include "qemu/module.h"
37 #include "qemu/option.h"
38 #include "qapi/qmp/qdict.h"
39 #include "qapi/qobject-input-visitor.h"
40 #include "qapi/qapi-visit-block-core.h"
41 #include "qemu/bswap.h"
42 #include "qemu/bitmap.h"
43 #include "migration/blocker.h"
44 #include "parallels.h"
45 
46 /**************************************************************/
47 
48 #define HEADER_MAGIC "WithoutFreeSpace"
49 #define HEADER_MAGIC2 "WithouFreSpacExt"
50 #define HEADER_VERSION 2
51 #define HEADER_INUSE_MAGIC  (0x746F6E59)
52 #define MAX_PARALLELS_IMAGE_FACTOR (1ull << 32)
53 
54 static QEnumLookup prealloc_mode_lookup = {
55     .array = (const char *const[]) {
56         "falloc",
57         "truncate",
58     },
59     .size = PRL_PREALLOC_MODE__MAX
60 };
61 
62 #define PARALLELS_OPT_PREALLOC_MODE     "prealloc-mode"
63 #define PARALLELS_OPT_PREALLOC_SIZE     "prealloc-size"
64 
65 static QemuOptsList parallels_runtime_opts = {
66     .name = "parallels",
67     .head = QTAILQ_HEAD_INITIALIZER(parallels_runtime_opts.head),
68     .desc = {
69         {
70             .name = PARALLELS_OPT_PREALLOC_SIZE,
71             .type = QEMU_OPT_SIZE,
72             .help = "Preallocation size on image expansion",
73             .def_value_str = "128M",
74         },
75         {
76             .name = PARALLELS_OPT_PREALLOC_MODE,
77             .type = QEMU_OPT_STRING,
78             .help = "Preallocation mode on image expansion "
79                     "(allowed values: falloc, truncate)",
80             .def_value_str = "falloc",
81         },
82         { /* end of list */ },
83     },
84 };
85 
86 static QemuOptsList parallels_create_opts = {
87     .name = "parallels-create-opts",
88     .head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
89     .desc = {
90         {
91             .name = BLOCK_OPT_SIZE,
92             .type = QEMU_OPT_SIZE,
93             .help = "Virtual disk size",
94         },
95         {
96             .name = BLOCK_OPT_CLUSTER_SIZE,
97             .type = QEMU_OPT_SIZE,
98             .help = "Parallels image cluster size",
99             .def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
100         },
101         { /* end of list */ }
102     }
103 };
104 
105 
106 static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx)
107 {
108     return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier;
109 }
110 
111 static uint32_t bat_entry_off(uint32_t idx)
112 {
113     return sizeof(ParallelsHeader) + sizeof(uint32_t) * idx;
114 }
115 
116 static int64_t seek_to_sector(BDRVParallelsState *s, int64_t sector_num)
117 {
118     uint32_t index, offset;
119 
120     index = sector_num / s->tracks;
121     offset = sector_num % s->tracks;
122 
123     /* not allocated */
124     if ((index >= s->bat_size) || (s->bat_bitmap[index] == 0)) {
125         return -1;
126     }
127     return bat2sect(s, index) + offset;
128 }
129 
130 static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
131         int nb_sectors)
132 {
133     int ret = s->tracks - sector_num % s->tracks;
134     return MIN(nb_sectors, ret);
135 }
136 
137 static int64_t block_status(BDRVParallelsState *s, int64_t sector_num,
138                             int nb_sectors, int *pnum)
139 {
140     int64_t start_off = -2, prev_end_off = -2;
141 
142     *pnum = 0;
143     while (nb_sectors > 0 || start_off == -2) {
144         int64_t offset = seek_to_sector(s, sector_num);
145         int to_end;
146 
147         if (start_off == -2) {
148             start_off = offset;
149             prev_end_off = offset;
150         } else if (offset != prev_end_off) {
151             break;
152         }
153 
154         to_end = cluster_remainder(s, sector_num, nb_sectors);
155         nb_sectors -= to_end;
156         sector_num += to_end;
157         *pnum += to_end;
158 
159         if (offset > 0) {
160             prev_end_off += to_end;
161         }
162     }
163     return start_off;
164 }
165 
166 static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num,
167                                  int nb_sectors, int *pnum)
168 {
169     int ret = 0;
170     BDRVParallelsState *s = bs->opaque;
171     int64_t pos, space, idx, to_allocate, i, len;
172 
173     pos = block_status(s, sector_num, nb_sectors, pnum);
174     if (pos > 0) {
175         return pos;
176     }
177 
178     idx = sector_num / s->tracks;
179     to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
180 
181     /* This function is called only by parallels_co_writev(), which will never
182      * pass a sector_num at or beyond the end of the image (because the block
183      * layer never passes such a sector_num to that function). Therefore, idx
184      * is always below s->bat_size.
185      * block_status() will limit *pnum so that sector_num + *pnum will not
186      * exceed the image end. Therefore, idx + to_allocate cannot exceed
187      * s->bat_size.
188      * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
189      * will always fit into a uint32_t. */
190     assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
191 
192     space = to_allocate * s->tracks;
193     len = bdrv_getlength(bs->file->bs);
194     if (len < 0) {
195         return len;
196     }
197     if (s->data_end + space > (len >> BDRV_SECTOR_BITS)) {
198         space += s->prealloc_size;
199         /*
200          * We require the expanded size to read back as zero. If the
201          * user permitted truncation, we try that; but if it fails, we
202          * force the safer-but-slower fallocate.
203          */
204         if (s->prealloc_mode == PRL_PREALLOC_MODE_TRUNCATE) {
205             ret = bdrv_truncate(bs->file,
206                                 (s->data_end + space) << BDRV_SECTOR_BITS,
207                                 false, PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE,
208                                 NULL);
209             if (ret == -ENOTSUP) {
210                 s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
211             }
212         }
213         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
214             ret = bdrv_pwrite_zeroes(bs->file,
215                                      s->data_end << BDRV_SECTOR_BITS,
216                                      space << BDRV_SECTOR_BITS, 0);
217         }
218         if (ret < 0) {
219             return ret;
220         }
221     }
222 
223     /* Try to read from backing to fill empty clusters
224      * FIXME: 1. previous write_zeroes may be redundant
225      *        2. most of data we read from backing will be rewritten by
226      *           parallels_co_writev. On aligned-to-cluster write we do not need
227      *           this read at all.
228      *        3. it would be good to combine write of data from backing and new
229      *           data into one write call */
230     if (bs->backing) {
231         int64_t nb_cow_sectors = to_allocate * s->tracks;
232         int64_t nb_cow_bytes = nb_cow_sectors << BDRV_SECTOR_BITS;
233         void *buf = qemu_blockalign(bs, nb_cow_bytes);
234 
235         ret = bdrv_co_pread(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
236                             nb_cow_bytes, buf, 0);
237         if (ret < 0) {
238             qemu_vfree(buf);
239             return ret;
240         }
241 
242         ret = bdrv_co_pwritev(bs->file, s->data_end * BDRV_SECTOR_SIZE,
243                               nb_cow_bytes, buf, 0);
244         qemu_vfree(buf);
245         if (ret < 0) {
246             return ret;
247         }
248     }
249 
250     for (i = 0; i < to_allocate; i++) {
251         s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
252         s->data_end += s->tracks;
253         bitmap_set(s->bat_dirty_bmap,
254                    bat_entry_off(idx + i) / s->bat_dirty_block, 1);
255     }
256 
257     return bat2sect(s, idx) + sector_num % s->tracks;
258 }
259 
260 
261 static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
262 {
263     BDRVParallelsState *s = bs->opaque;
264     unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
265     unsigned long bit;
266 
267     qemu_co_mutex_lock(&s->lock);
268 
269     bit = find_first_bit(s->bat_dirty_bmap, size);
270     while (bit < size) {
271         uint32_t off = bit * s->bat_dirty_block;
272         uint32_t to_write = s->bat_dirty_block;
273         int ret;
274 
275         if (off + to_write > s->header_size) {
276             to_write = s->header_size - off;
277         }
278         ret = bdrv_pwrite(bs->file, off, (uint8_t *)s->header + off,
279                           to_write);
280         if (ret < 0) {
281             qemu_co_mutex_unlock(&s->lock);
282             return ret;
283         }
284         bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
285     }
286     bitmap_zero(s->bat_dirty_bmap, size);
287 
288     qemu_co_mutex_unlock(&s->lock);
289     return 0;
290 }
291 
292 
293 static int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
294                                                   bool want_zero,
295                                                   int64_t offset,
296                                                   int64_t bytes,
297                                                   int64_t *pnum,
298                                                   int64_t *map,
299                                                   BlockDriverState **file)
300 {
301     BDRVParallelsState *s = bs->opaque;
302     int count;
303 
304     assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
305     qemu_co_mutex_lock(&s->lock);
306     offset = block_status(s, offset >> BDRV_SECTOR_BITS,
307                           bytes >> BDRV_SECTOR_BITS, &count);
308     qemu_co_mutex_unlock(&s->lock);
309 
310     *pnum = count * BDRV_SECTOR_SIZE;
311     if (offset < 0) {
312         return 0;
313     }
314 
315     *map = offset * BDRV_SECTOR_SIZE;
316     *file = bs->file->bs;
317     return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
318 }
319 
320 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
321                                             int64_t sector_num, int nb_sectors,
322                                             QEMUIOVector *qiov, int flags)
323 {
324     BDRVParallelsState *s = bs->opaque;
325     uint64_t bytes_done = 0;
326     QEMUIOVector hd_qiov;
327     int ret = 0;
328 
329     assert(!flags);
330     qemu_iovec_init(&hd_qiov, qiov->niov);
331 
332     while (nb_sectors > 0) {
333         int64_t position;
334         int n, nbytes;
335 
336         qemu_co_mutex_lock(&s->lock);
337         position = allocate_clusters(bs, sector_num, nb_sectors, &n);
338         qemu_co_mutex_unlock(&s->lock);
339         if (position < 0) {
340             ret = (int)position;
341             break;
342         }
343 
344         nbytes = n << BDRV_SECTOR_BITS;
345 
346         qemu_iovec_reset(&hd_qiov);
347         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
348 
349         ret = bdrv_co_pwritev(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
350                               &hd_qiov, 0);
351         if (ret < 0) {
352             break;
353         }
354 
355         nb_sectors -= n;
356         sector_num += n;
357         bytes_done += nbytes;
358     }
359 
360     qemu_iovec_destroy(&hd_qiov);
361     return ret;
362 }
363 
364 static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
365         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
366 {
367     BDRVParallelsState *s = bs->opaque;
368     uint64_t bytes_done = 0;
369     QEMUIOVector hd_qiov;
370     int ret = 0;
371 
372     qemu_iovec_init(&hd_qiov, qiov->niov);
373 
374     while (nb_sectors > 0) {
375         int64_t position;
376         int n, nbytes;
377 
378         qemu_co_mutex_lock(&s->lock);
379         position = block_status(s, sector_num, nb_sectors, &n);
380         qemu_co_mutex_unlock(&s->lock);
381 
382         nbytes = n << BDRV_SECTOR_BITS;
383 
384         qemu_iovec_reset(&hd_qiov);
385         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
386 
387         if (position < 0) {
388             if (bs->backing) {
389                 ret = bdrv_co_preadv(bs->backing, sector_num * BDRV_SECTOR_SIZE,
390                                      nbytes, &hd_qiov, 0);
391                 if (ret < 0) {
392                     break;
393                 }
394             } else {
395                 qemu_iovec_memset(&hd_qiov, 0, 0, nbytes);
396             }
397         } else {
398             ret = bdrv_co_preadv(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
399                                  &hd_qiov, 0);
400             if (ret < 0) {
401                 break;
402             }
403         }
404 
405         nb_sectors -= n;
406         sector_num += n;
407         bytes_done += nbytes;
408     }
409 
410     qemu_iovec_destroy(&hd_qiov);
411     return ret;
412 }
413 
414 
415 static int coroutine_fn parallels_co_check(BlockDriverState *bs,
416                                            BdrvCheckResult *res,
417                                            BdrvCheckMode fix)
418 {
419     BDRVParallelsState *s = bs->opaque;
420     int64_t size, prev_off, high_off;
421     int ret;
422     uint32_t i;
423     bool flush_bat = false;
424     int cluster_size = s->tracks << BDRV_SECTOR_BITS;
425 
426     size = bdrv_getlength(bs->file->bs);
427     if (size < 0) {
428         res->check_errors++;
429         return size;
430     }
431 
432     qemu_co_mutex_lock(&s->lock);
433     if (s->header_unclean) {
434         fprintf(stderr, "%s image was not closed correctly\n",
435                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
436         res->corruptions++;
437         if (fix & BDRV_FIX_ERRORS) {
438             /* parallels_close will do the job right */
439             res->corruptions_fixed++;
440             s->header_unclean = false;
441         }
442     }
443 
444     res->bfi.total_clusters = s->bat_size;
445     res->bfi.compressed_clusters = 0; /* compression is not supported */
446 
447     high_off = 0;
448     prev_off = 0;
449     for (i = 0; i < s->bat_size; i++) {
450         int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
451         if (off == 0) {
452             prev_off = 0;
453             continue;
454         }
455 
456         /* cluster outside the image */
457         if (off > size) {
458             fprintf(stderr, "%s cluster %u is outside image\n",
459                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
460             res->corruptions++;
461             if (fix & BDRV_FIX_ERRORS) {
462                 prev_off = 0;
463                 s->bat_bitmap[i] = 0;
464                 res->corruptions_fixed++;
465                 flush_bat = true;
466                 continue;
467             }
468         }
469 
470         res->bfi.allocated_clusters++;
471         if (off > high_off) {
472             high_off = off;
473         }
474 
475         if (prev_off != 0 && (prev_off + cluster_size) != off) {
476             res->bfi.fragmented_clusters++;
477         }
478         prev_off = off;
479     }
480 
481     ret = 0;
482     if (flush_bat) {
483         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
484         if (ret < 0) {
485             res->check_errors++;
486             goto out;
487         }
488     }
489 
490     res->image_end_offset = high_off + cluster_size;
491     if (size > res->image_end_offset) {
492         int64_t count;
493         count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
494         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
495                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
496                 size - res->image_end_offset);
497         res->leaks += count;
498         if (fix & BDRV_FIX_LEAKS) {
499             Error *local_err = NULL;
500 
501             /*
502              * In order to really repair the image, we must shrink it.
503              * That means we have to pass exact=true.
504              */
505             ret = bdrv_truncate(bs->file, res->image_end_offset, true,
506                                 PREALLOC_MODE_OFF, 0, &local_err);
507             if (ret < 0) {
508                 error_report_err(local_err);
509                 res->check_errors++;
510                 goto out;
511             }
512             res->leaks_fixed += count;
513         }
514     }
515 
516 out:
517     qemu_co_mutex_unlock(&s->lock);
518     return ret;
519 }
520 
521 
522 static int coroutine_fn parallels_co_create(BlockdevCreateOptions* opts,
523                                             Error **errp)
524 {
525     BlockdevCreateOptionsParallels *parallels_opts;
526     BlockDriverState *bs;
527     BlockBackend *blk;
528     int64_t total_size, cl_size;
529     uint32_t bat_entries, bat_sectors;
530     ParallelsHeader header;
531     uint8_t tmp[BDRV_SECTOR_SIZE];
532     int ret;
533 
534     assert(opts->driver == BLOCKDEV_DRIVER_PARALLELS);
535     parallels_opts = &opts->u.parallels;
536 
537     /* Sanity checks */
538     total_size = parallels_opts->size;
539 
540     if (parallels_opts->has_cluster_size) {
541         cl_size = parallels_opts->cluster_size;
542     } else {
543         cl_size = DEFAULT_CLUSTER_SIZE;
544     }
545 
546     /* XXX What is the real limit here? This is an insanely large maximum. */
547     if (cl_size >= INT64_MAX / MAX_PARALLELS_IMAGE_FACTOR) {
548         error_setg(errp, "Cluster size is too large");
549         return -EINVAL;
550     }
551     if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
552         error_setg(errp, "Image size is too large for this cluster size");
553         return -E2BIG;
554     }
555 
556     if (!QEMU_IS_ALIGNED(total_size, BDRV_SECTOR_SIZE)) {
557         error_setg(errp, "Image size must be a multiple of 512 bytes");
558         return -EINVAL;
559     }
560 
561     if (!QEMU_IS_ALIGNED(cl_size, BDRV_SECTOR_SIZE)) {
562         error_setg(errp, "Cluster size must be a multiple of 512 bytes");
563         return -EINVAL;
564     }
565 
566     /* Create BlockBackend to write to the image */
567     bs = bdrv_open_blockdev_ref(parallels_opts->file, errp);
568     if (bs == NULL) {
569         return -EIO;
570     }
571 
572     blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
573                           errp);
574     if (!blk) {
575         ret = -EPERM;
576         goto out;
577     }
578     blk_set_allow_write_beyond_eof(blk, true);
579 
580     /* Create image format */
581     bat_entries = DIV_ROUND_UP(total_size, cl_size);
582     bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
583     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
584 
585     memset(&header, 0, sizeof(header));
586     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
587     header.version = cpu_to_le32(HEADER_VERSION);
588     /* don't care much about geometry, it is not used on image level */
589     header.heads = cpu_to_le32(HEADS_NUMBER);
590     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE
591                                    / HEADS_NUMBER / SEC_IN_CYL);
592     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
593     header.bat_entries = cpu_to_le32(bat_entries);
594     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
595     header.data_off = cpu_to_le32(bat_sectors);
596 
597     /* write all the data */
598     memset(tmp, 0, sizeof(tmp));
599     memcpy(tmp, &header, sizeof(header));
600 
601     ret = blk_pwrite(blk, 0, tmp, BDRV_SECTOR_SIZE, 0);
602     if (ret < 0) {
603         goto exit;
604     }
605     ret = blk_pwrite_zeroes(blk, BDRV_SECTOR_SIZE,
606                             (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
607     if (ret < 0) {
608         goto exit;
609     }
610 
611     ret = 0;
612 out:
613     blk_unref(blk);
614     bdrv_unref(bs);
615     return ret;
616 
617 exit:
618     error_setg_errno(errp, -ret, "Failed to create Parallels image");
619     goto out;
620 }
621 
622 static int coroutine_fn parallels_co_create_opts(BlockDriver *drv,
623                                                  const char *filename,
624                                                  QemuOpts *opts,
625                                                  Error **errp)
626 {
627     BlockdevCreateOptions *create_options = NULL;
628     Error *local_err = NULL;
629     BlockDriverState *bs = NULL;
630     QDict *qdict;
631     Visitor *v;
632     int ret;
633 
634     static const QDictRenames opt_renames[] = {
635         { BLOCK_OPT_CLUSTER_SIZE,       "cluster-size" },
636         { NULL, NULL },
637     };
638 
639     /* Parse options and convert legacy syntax */
640     qdict = qemu_opts_to_qdict_filtered(opts, NULL, &parallels_create_opts,
641                                         true);
642 
643     if (!qdict_rename_keys(qdict, opt_renames, errp)) {
644         ret = -EINVAL;
645         goto done;
646     }
647 
648     /* Create and open the file (protocol layer) */
649     ret = bdrv_create_file(filename, opts, &local_err);
650     if (ret < 0) {
651         error_propagate(errp, local_err);
652         goto done;
653     }
654 
655     bs = bdrv_open(filename, NULL, NULL,
656                    BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
657     if (bs == NULL) {
658         ret = -EIO;
659         goto done;
660     }
661 
662     /* Now get the QAPI type BlockdevCreateOptions */
663     qdict_put_str(qdict, "driver", "parallels");
664     qdict_put_str(qdict, "file", bs->node_name);
665 
666     v = qobject_input_visitor_new_flat_confused(qdict, errp);
667     if (!v) {
668         ret = -EINVAL;
669         goto done;
670     }
671 
672     visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
673     visit_free(v);
674 
675     if (local_err) {
676         error_propagate(errp, local_err);
677         ret = -EINVAL;
678         goto done;
679     }
680 
681     /* Silently round up sizes */
682     create_options->u.parallels.size =
683         ROUND_UP(create_options->u.parallels.size, BDRV_SECTOR_SIZE);
684     create_options->u.parallels.cluster_size =
685         ROUND_UP(create_options->u.parallels.cluster_size, BDRV_SECTOR_SIZE);
686 
687     /* Create the Parallels image (format layer) */
688     ret = parallels_co_create(create_options, errp);
689     if (ret < 0) {
690         goto done;
691     }
692     ret = 0;
693 
694 done:
695     qobject_unref(qdict);
696     bdrv_unref(bs);
697     qapi_free_BlockdevCreateOptions(create_options);
698     return ret;
699 }
700 
701 
702 static int parallels_probe(const uint8_t *buf, int buf_size,
703                            const char *filename)
704 {
705     const ParallelsHeader *ph = (const void *)buf;
706 
707     if (buf_size < sizeof(ParallelsHeader)) {
708         return 0;
709     }
710 
711     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
712            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
713            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
714         return 100;
715     }
716 
717     return 0;
718 }
719 
720 static int parallels_update_header(BlockDriverState *bs)
721 {
722     BDRVParallelsState *s = bs->opaque;
723     unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
724                         sizeof(ParallelsHeader));
725 
726     if (size > s->header_size) {
727         size = s->header_size;
728     }
729     return bdrv_pwrite_sync(bs->file, 0, s->header, size);
730 }
731 
732 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
733                           Error **errp)
734 {
735     BDRVParallelsState *s = bs->opaque;
736     ParallelsHeader ph;
737     int ret, size, i;
738     QemuOpts *opts = NULL;
739     Error *local_err = NULL;
740     char *buf;
741 
742     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
743                                BDRV_CHILD_IMAGE, false, errp);
744     if (!bs->file) {
745         return -EINVAL;
746     }
747 
748     ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
749     if (ret < 0) {
750         goto fail;
751     }
752 
753     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
754 
755     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
756         goto fail_format;
757     }
758     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
759         s->off_multiplier = 1;
760         bs->total_sectors = 0xffffffff & bs->total_sectors;
761     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
762         s->off_multiplier = le32_to_cpu(ph.tracks);
763     } else {
764         goto fail_format;
765     }
766 
767     s->tracks = le32_to_cpu(ph.tracks);
768     if (s->tracks == 0) {
769         error_setg(errp, "Invalid image: Zero sectors per track");
770         ret = -EINVAL;
771         goto fail;
772     }
773     if (s->tracks > INT32_MAX/513) {
774         error_setg(errp, "Invalid image: Too big cluster");
775         ret = -EFBIG;
776         goto fail;
777     }
778 
779     s->bat_size = le32_to_cpu(ph.bat_entries);
780     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
781         error_setg(errp, "Catalog too large");
782         ret = -EFBIG;
783         goto fail;
784     }
785 
786     size = bat_entry_off(s->bat_size);
787     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
788     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
789     if (s->header == NULL) {
790         ret = -ENOMEM;
791         goto fail;
792     }
793     s->data_end = le32_to_cpu(ph.data_off);
794     if (s->data_end == 0) {
795         s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
796     }
797     if (s->data_end < s->header_size) {
798         /* there is not enough unused space to fit to block align between BAT
799            and actual data. We can't avoid read-modify-write... */
800         s->header_size = size;
801     }
802 
803     ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
804     if (ret < 0) {
805         goto fail;
806     }
807     s->bat_bitmap = (uint32_t *)(s->header + 1);
808 
809     for (i = 0; i < s->bat_size; i++) {
810         int64_t off = bat2sect(s, i);
811         if (off >= s->data_end) {
812             s->data_end = off + s->tracks;
813         }
814     }
815 
816     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
817         /* Image was not closed correctly. The check is mandatory */
818         s->header_unclean = true;
819         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
820             error_setg(errp, "parallels: Image was not closed correctly; "
821                        "cannot be opened read/write");
822             ret = -EACCES;
823             goto fail;
824         }
825     }
826 
827     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, &local_err);
828     if (local_err != NULL) {
829         goto fail_options;
830     }
831 
832     qemu_opts_absorb_qdict(opts, options, &local_err);
833     if (local_err != NULL) {
834         goto fail_options;
835     }
836 
837     s->prealloc_size =
838         qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
839     s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
840     buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
841     /* prealloc_mode can be downgraded later during allocate_clusters */
842     s->prealloc_mode = qapi_enum_parse(&prealloc_mode_lookup, buf,
843                                        PRL_PREALLOC_MODE_FALLOCATE,
844                                        &local_err);
845     g_free(buf);
846     if (local_err != NULL) {
847         goto fail_options;
848     }
849 
850     if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
851         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
852         ret = parallels_update_header(bs);
853         if (ret < 0) {
854             goto fail;
855         }
856     }
857 
858     s->bat_dirty_block = 4 * qemu_real_host_page_size;
859     s->bat_dirty_bmap =
860         bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
861 
862     /* Disable migration until bdrv_invalidate_cache method is added */
863     error_setg(&s->migration_blocker, "The Parallels format used by node '%s' "
864                "does not support live migration",
865                bdrv_get_device_or_node_name(bs));
866     ret = migrate_add_blocker(s->migration_blocker, &local_err);
867     if (local_err) {
868         error_propagate(errp, local_err);
869         error_free(s->migration_blocker);
870         goto fail;
871     }
872     qemu_co_mutex_init(&s->lock);
873     return 0;
874 
875 fail_format:
876     error_setg(errp, "Image not in Parallels format");
877     ret = -EINVAL;
878 fail:
879     qemu_vfree(s->header);
880     return ret;
881 
882 fail_options:
883     error_propagate(errp, local_err);
884     ret = -EINVAL;
885     goto fail;
886 }
887 
888 
889 static void parallels_close(BlockDriverState *bs)
890 {
891     BDRVParallelsState *s = bs->opaque;
892 
893     if ((bs->open_flags & BDRV_O_RDWR) && !(bs->open_flags & BDRV_O_INACTIVE)) {
894         s->header->inuse = 0;
895         parallels_update_header(bs);
896 
897         /* errors are ignored, so we might as well pass exact=true */
898         bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS, true,
899                       PREALLOC_MODE_OFF, 0, NULL);
900     }
901 
902     g_free(s->bat_dirty_bmap);
903     qemu_vfree(s->header);
904 
905     migrate_del_blocker(s->migration_blocker);
906     error_free(s->migration_blocker);
907 }
908 
909 static BlockDriver bdrv_parallels = {
910     .format_name	= "parallels",
911     .instance_size	= sizeof(BDRVParallelsState),
912     .bdrv_probe		= parallels_probe,
913     .bdrv_open		= parallels_open,
914     .bdrv_close		= parallels_close,
915     .bdrv_child_perm          = bdrv_default_perms,
916     .bdrv_co_block_status     = parallels_co_block_status,
917     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
918     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
919     .bdrv_co_readv  = parallels_co_readv,
920     .bdrv_co_writev = parallels_co_writev,
921     .is_format      = true,
922     .supports_backing = true,
923     .bdrv_co_create      = parallels_co_create,
924     .bdrv_co_create_opts = parallels_co_create_opts,
925     .bdrv_co_check  = parallels_co_check,
926     .create_opts    = &parallels_create_opts,
927 };
928 
929 static void bdrv_parallels_init(void)
930 {
931     bdrv_register(&bdrv_parallels);
932 }
933 
934 block_init(bdrv_parallels_init);
935