xref: /openbmc/qemu/block/parallels.c (revision ddda3748)
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;
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         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
200             ret = bdrv_pwrite_zeroes(bs->file,
201                                      s->data_end << BDRV_SECTOR_BITS,
202                                      space << BDRV_SECTOR_BITS, 0);
203         } else {
204             ret = bdrv_truncate(bs->file,
205                                 (s->data_end + space) << BDRV_SECTOR_BITS,
206                                 false, PREALLOC_MODE_OFF, NULL);
207         }
208         if (ret < 0) {
209             return ret;
210         }
211     }
212 
213     /* Try to read from backing to fill empty clusters
214      * FIXME: 1. previous write_zeroes may be redundant
215      *        2. most of data we read from backing will be rewritten by
216      *           parallels_co_writev. On aligned-to-cluster write we do not need
217      *           this read at all.
218      *        3. it would be good to combine write of data from backing and new
219      *           data into one write call */
220     if (bs->backing) {
221         int64_t nb_cow_sectors = to_allocate * s->tracks;
222         int64_t nb_cow_bytes = nb_cow_sectors << BDRV_SECTOR_BITS;
223         void *buf = qemu_blockalign(bs, nb_cow_bytes);
224 
225         ret = bdrv_co_pread(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
226                             nb_cow_bytes, buf, 0);
227         if (ret < 0) {
228             qemu_vfree(buf);
229             return ret;
230         }
231 
232         ret = bdrv_co_pwritev(bs->file, s->data_end * BDRV_SECTOR_SIZE,
233                               nb_cow_bytes, buf, 0);
234         qemu_vfree(buf);
235         if (ret < 0) {
236             return ret;
237         }
238     }
239 
240     for (i = 0; i < to_allocate; i++) {
241         s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
242         s->data_end += s->tracks;
243         bitmap_set(s->bat_dirty_bmap,
244                    bat_entry_off(idx + i) / s->bat_dirty_block, 1);
245     }
246 
247     return bat2sect(s, idx) + sector_num % s->tracks;
248 }
249 
250 
251 static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
252 {
253     BDRVParallelsState *s = bs->opaque;
254     unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
255     unsigned long bit;
256 
257     qemu_co_mutex_lock(&s->lock);
258 
259     bit = find_first_bit(s->bat_dirty_bmap, size);
260     while (bit < size) {
261         uint32_t off = bit * s->bat_dirty_block;
262         uint32_t to_write = s->bat_dirty_block;
263         int ret;
264 
265         if (off + to_write > s->header_size) {
266             to_write = s->header_size - off;
267         }
268         ret = bdrv_pwrite(bs->file, off, (uint8_t *)s->header + off,
269                           to_write);
270         if (ret < 0) {
271             qemu_co_mutex_unlock(&s->lock);
272             return ret;
273         }
274         bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
275     }
276     bitmap_zero(s->bat_dirty_bmap, size);
277 
278     qemu_co_mutex_unlock(&s->lock);
279     return 0;
280 }
281 
282 
283 static int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
284                                                   bool want_zero,
285                                                   int64_t offset,
286                                                   int64_t bytes,
287                                                   int64_t *pnum,
288                                                   int64_t *map,
289                                                   BlockDriverState **file)
290 {
291     BDRVParallelsState *s = bs->opaque;
292     int count;
293 
294     assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
295     qemu_co_mutex_lock(&s->lock);
296     offset = block_status(s, offset >> BDRV_SECTOR_BITS,
297                           bytes >> BDRV_SECTOR_BITS, &count);
298     qemu_co_mutex_unlock(&s->lock);
299 
300     *pnum = count * BDRV_SECTOR_SIZE;
301     if (offset < 0) {
302         return 0;
303     }
304 
305     *map = offset * BDRV_SECTOR_SIZE;
306     *file = bs->file->bs;
307     return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
308 }
309 
310 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
311                                             int64_t sector_num, int nb_sectors,
312                                             QEMUIOVector *qiov, int flags)
313 {
314     BDRVParallelsState *s = bs->opaque;
315     uint64_t bytes_done = 0;
316     QEMUIOVector hd_qiov;
317     int ret = 0;
318 
319     assert(!flags);
320     qemu_iovec_init(&hd_qiov, qiov->niov);
321 
322     while (nb_sectors > 0) {
323         int64_t position;
324         int n, nbytes;
325 
326         qemu_co_mutex_lock(&s->lock);
327         position = allocate_clusters(bs, sector_num, nb_sectors, &n);
328         qemu_co_mutex_unlock(&s->lock);
329         if (position < 0) {
330             ret = (int)position;
331             break;
332         }
333 
334         nbytes = n << BDRV_SECTOR_BITS;
335 
336         qemu_iovec_reset(&hd_qiov);
337         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
338 
339         ret = bdrv_co_pwritev(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
340                               &hd_qiov, 0);
341         if (ret < 0) {
342             break;
343         }
344 
345         nb_sectors -= n;
346         sector_num += n;
347         bytes_done += nbytes;
348     }
349 
350     qemu_iovec_destroy(&hd_qiov);
351     return ret;
352 }
353 
354 static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
355         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
356 {
357     BDRVParallelsState *s = bs->opaque;
358     uint64_t bytes_done = 0;
359     QEMUIOVector hd_qiov;
360     int ret = 0;
361 
362     qemu_iovec_init(&hd_qiov, qiov->niov);
363 
364     while (nb_sectors > 0) {
365         int64_t position;
366         int n, nbytes;
367 
368         qemu_co_mutex_lock(&s->lock);
369         position = block_status(s, sector_num, nb_sectors, &n);
370         qemu_co_mutex_unlock(&s->lock);
371 
372         nbytes = n << BDRV_SECTOR_BITS;
373 
374         qemu_iovec_reset(&hd_qiov);
375         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
376 
377         if (position < 0) {
378             if (bs->backing) {
379                 ret = bdrv_co_preadv(bs->backing, sector_num * BDRV_SECTOR_SIZE,
380                                      nbytes, &hd_qiov, 0);
381                 if (ret < 0) {
382                     break;
383                 }
384             } else {
385                 qemu_iovec_memset(&hd_qiov, 0, 0, nbytes);
386             }
387         } else {
388             ret = bdrv_co_preadv(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
389                                  &hd_qiov, 0);
390             if (ret < 0) {
391                 break;
392             }
393         }
394 
395         nb_sectors -= n;
396         sector_num += n;
397         bytes_done += nbytes;
398     }
399 
400     qemu_iovec_destroy(&hd_qiov);
401     return ret;
402 }
403 
404 
405 static int coroutine_fn parallels_co_check(BlockDriverState *bs,
406                                            BdrvCheckResult *res,
407                                            BdrvCheckMode fix)
408 {
409     BDRVParallelsState *s = bs->opaque;
410     int64_t size, prev_off, high_off;
411     int ret;
412     uint32_t i;
413     bool flush_bat = false;
414     int cluster_size = s->tracks << BDRV_SECTOR_BITS;
415 
416     size = bdrv_getlength(bs->file->bs);
417     if (size < 0) {
418         res->check_errors++;
419         return size;
420     }
421 
422     qemu_co_mutex_lock(&s->lock);
423     if (s->header_unclean) {
424         fprintf(stderr, "%s image was not closed correctly\n",
425                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
426         res->corruptions++;
427         if (fix & BDRV_FIX_ERRORS) {
428             /* parallels_close will do the job right */
429             res->corruptions_fixed++;
430             s->header_unclean = false;
431         }
432     }
433 
434     res->bfi.total_clusters = s->bat_size;
435     res->bfi.compressed_clusters = 0; /* compression is not supported */
436 
437     high_off = 0;
438     prev_off = 0;
439     for (i = 0; i < s->bat_size; i++) {
440         int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
441         if (off == 0) {
442             prev_off = 0;
443             continue;
444         }
445 
446         /* cluster outside the image */
447         if (off > size) {
448             fprintf(stderr, "%s cluster %u is outside image\n",
449                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
450             res->corruptions++;
451             if (fix & BDRV_FIX_ERRORS) {
452                 prev_off = 0;
453                 s->bat_bitmap[i] = 0;
454                 res->corruptions_fixed++;
455                 flush_bat = true;
456                 continue;
457             }
458         }
459 
460         res->bfi.allocated_clusters++;
461         if (off > high_off) {
462             high_off = off;
463         }
464 
465         if (prev_off != 0 && (prev_off + cluster_size) != off) {
466             res->bfi.fragmented_clusters++;
467         }
468         prev_off = off;
469     }
470 
471     ret = 0;
472     if (flush_bat) {
473         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
474         if (ret < 0) {
475             res->check_errors++;
476             goto out;
477         }
478     }
479 
480     res->image_end_offset = high_off + cluster_size;
481     if (size > res->image_end_offset) {
482         int64_t count;
483         count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
484         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
485                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
486                 size - res->image_end_offset);
487         res->leaks += count;
488         if (fix & BDRV_FIX_LEAKS) {
489             Error *local_err = NULL;
490 
491             /*
492              * In order to really repair the image, we must shrink it.
493              * That means we have to pass exact=true.
494              */
495             ret = bdrv_truncate(bs->file, res->image_end_offset, true,
496                                 PREALLOC_MODE_OFF, &local_err);
497             if (ret < 0) {
498                 error_report_err(local_err);
499                 res->check_errors++;
500                 goto out;
501             }
502             res->leaks_fixed += count;
503         }
504     }
505 
506 out:
507     qemu_co_mutex_unlock(&s->lock);
508     return ret;
509 }
510 
511 
512 static int coroutine_fn parallels_co_create(BlockdevCreateOptions* opts,
513                                             Error **errp)
514 {
515     BlockdevCreateOptionsParallels *parallels_opts;
516     BlockDriverState *bs;
517     BlockBackend *blk;
518     int64_t total_size, cl_size;
519     uint32_t bat_entries, bat_sectors;
520     ParallelsHeader header;
521     uint8_t tmp[BDRV_SECTOR_SIZE];
522     int ret;
523 
524     assert(opts->driver == BLOCKDEV_DRIVER_PARALLELS);
525     parallels_opts = &opts->u.parallels;
526 
527     /* Sanity checks */
528     total_size = parallels_opts->size;
529 
530     if (parallels_opts->has_cluster_size) {
531         cl_size = parallels_opts->cluster_size;
532     } else {
533         cl_size = DEFAULT_CLUSTER_SIZE;
534     }
535 
536     /* XXX What is the real limit here? This is an insanely large maximum. */
537     if (cl_size >= INT64_MAX / MAX_PARALLELS_IMAGE_FACTOR) {
538         error_setg(errp, "Cluster size is too large");
539         return -EINVAL;
540     }
541     if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
542         error_setg(errp, "Image size is too large for this cluster size");
543         return -E2BIG;
544     }
545 
546     if (!QEMU_IS_ALIGNED(total_size, BDRV_SECTOR_SIZE)) {
547         error_setg(errp, "Image size must be a multiple of 512 bytes");
548         return -EINVAL;
549     }
550 
551     if (!QEMU_IS_ALIGNED(cl_size, BDRV_SECTOR_SIZE)) {
552         error_setg(errp, "Cluster size must be a multiple of 512 bytes");
553         return -EINVAL;
554     }
555 
556     /* Create BlockBackend to write to the image */
557     bs = bdrv_open_blockdev_ref(parallels_opts->file, errp);
558     if (bs == NULL) {
559         return -EIO;
560     }
561 
562     blk = blk_new(bdrv_get_aio_context(bs),
563                   BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
564     ret = blk_insert_bs(blk, bs, errp);
565     if (ret < 0) {
566         goto out;
567     }
568     blk_set_allow_write_beyond_eof(blk, true);
569 
570     /* Create image format */
571     bat_entries = DIV_ROUND_UP(total_size, cl_size);
572     bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
573     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
574 
575     memset(&header, 0, sizeof(header));
576     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
577     header.version = cpu_to_le32(HEADER_VERSION);
578     /* don't care much about geometry, it is not used on image level */
579     header.heads = cpu_to_le32(HEADS_NUMBER);
580     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE
581                                    / HEADS_NUMBER / SEC_IN_CYL);
582     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
583     header.bat_entries = cpu_to_le32(bat_entries);
584     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
585     header.data_off = cpu_to_le32(bat_sectors);
586 
587     /* write all the data */
588     memset(tmp, 0, sizeof(tmp));
589     memcpy(tmp, &header, sizeof(header));
590 
591     ret = blk_pwrite(blk, 0, tmp, BDRV_SECTOR_SIZE, 0);
592     if (ret < 0) {
593         goto exit;
594     }
595     ret = blk_pwrite_zeroes(blk, BDRV_SECTOR_SIZE,
596                             (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
597     if (ret < 0) {
598         goto exit;
599     }
600 
601     ret = 0;
602 out:
603     blk_unref(blk);
604     bdrv_unref(bs);
605     return ret;
606 
607 exit:
608     error_setg_errno(errp, -ret, "Failed to create Parallels image");
609     goto out;
610 }
611 
612 static int coroutine_fn parallels_co_create_opts(const char *filename,
613                                                  QemuOpts *opts,
614                                                  Error **errp)
615 {
616     BlockdevCreateOptions *create_options = NULL;
617     Error *local_err = NULL;
618     BlockDriverState *bs = NULL;
619     QDict *qdict;
620     Visitor *v;
621     int ret;
622 
623     static const QDictRenames opt_renames[] = {
624         { BLOCK_OPT_CLUSTER_SIZE,       "cluster-size" },
625         { NULL, NULL },
626     };
627 
628     /* Parse options and convert legacy syntax */
629     qdict = qemu_opts_to_qdict_filtered(opts, NULL, &parallels_create_opts,
630                                         true);
631 
632     if (!qdict_rename_keys(qdict, opt_renames, errp)) {
633         ret = -EINVAL;
634         goto done;
635     }
636 
637     /* Create and open the file (protocol layer) */
638     ret = bdrv_create_file(filename, opts, &local_err);
639     if (ret < 0) {
640         error_propagate(errp, local_err);
641         goto done;
642     }
643 
644     bs = bdrv_open(filename, NULL, NULL,
645                    BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
646     if (bs == NULL) {
647         ret = -EIO;
648         goto done;
649     }
650 
651     /* Now get the QAPI type BlockdevCreateOptions */
652     qdict_put_str(qdict, "driver", "parallels");
653     qdict_put_str(qdict, "file", bs->node_name);
654 
655     v = qobject_input_visitor_new_flat_confused(qdict, errp);
656     if (!v) {
657         ret = -EINVAL;
658         goto done;
659     }
660 
661     visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
662     visit_free(v);
663 
664     if (local_err) {
665         error_propagate(errp, local_err);
666         ret = -EINVAL;
667         goto done;
668     }
669 
670     /* Silently round up sizes */
671     create_options->u.parallels.size =
672         ROUND_UP(create_options->u.parallels.size, BDRV_SECTOR_SIZE);
673     create_options->u.parallels.cluster_size =
674         ROUND_UP(create_options->u.parallels.cluster_size, BDRV_SECTOR_SIZE);
675 
676     /* Create the Parallels image (format layer) */
677     ret = parallels_co_create(create_options, errp);
678     if (ret < 0) {
679         goto done;
680     }
681     ret = 0;
682 
683 done:
684     qobject_unref(qdict);
685     bdrv_unref(bs);
686     qapi_free_BlockdevCreateOptions(create_options);
687     return ret;
688 }
689 
690 
691 static int parallels_probe(const uint8_t *buf, int buf_size,
692                            const char *filename)
693 {
694     const ParallelsHeader *ph = (const void *)buf;
695 
696     if (buf_size < sizeof(ParallelsHeader)) {
697         return 0;
698     }
699 
700     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
701            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
702            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
703         return 100;
704     }
705 
706     return 0;
707 }
708 
709 static int parallels_update_header(BlockDriverState *bs)
710 {
711     BDRVParallelsState *s = bs->opaque;
712     unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
713                         sizeof(ParallelsHeader));
714 
715     if (size > s->header_size) {
716         size = s->header_size;
717     }
718     return bdrv_pwrite_sync(bs->file, 0, s->header, size);
719 }
720 
721 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
722                           Error **errp)
723 {
724     BDRVParallelsState *s = bs->opaque;
725     ParallelsHeader ph;
726     int ret, size, i;
727     QemuOpts *opts = NULL;
728     Error *local_err = NULL;
729     char *buf;
730 
731     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
732                                false, errp);
733     if (!bs->file) {
734         return -EINVAL;
735     }
736 
737     ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
738     if (ret < 0) {
739         goto fail;
740     }
741 
742     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
743 
744     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
745         goto fail_format;
746     }
747     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
748         s->off_multiplier = 1;
749         bs->total_sectors = 0xffffffff & bs->total_sectors;
750     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
751         s->off_multiplier = le32_to_cpu(ph.tracks);
752     } else {
753         goto fail_format;
754     }
755 
756     s->tracks = le32_to_cpu(ph.tracks);
757     if (s->tracks == 0) {
758         error_setg(errp, "Invalid image: Zero sectors per track");
759         ret = -EINVAL;
760         goto fail;
761     }
762     if (s->tracks > INT32_MAX/513) {
763         error_setg(errp, "Invalid image: Too big cluster");
764         ret = -EFBIG;
765         goto fail;
766     }
767 
768     s->bat_size = le32_to_cpu(ph.bat_entries);
769     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
770         error_setg(errp, "Catalog too large");
771         ret = -EFBIG;
772         goto fail;
773     }
774 
775     size = bat_entry_off(s->bat_size);
776     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
777     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
778     if (s->header == NULL) {
779         ret = -ENOMEM;
780         goto fail;
781     }
782     s->data_end = le32_to_cpu(ph.data_off);
783     if (s->data_end == 0) {
784         s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
785     }
786     if (s->data_end < s->header_size) {
787         /* there is not enough unused space to fit to block align between BAT
788            and actual data. We can't avoid read-modify-write... */
789         s->header_size = size;
790     }
791 
792     ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
793     if (ret < 0) {
794         goto fail;
795     }
796     s->bat_bitmap = (uint32_t *)(s->header + 1);
797 
798     for (i = 0; i < s->bat_size; i++) {
799         int64_t off = bat2sect(s, i);
800         if (off >= s->data_end) {
801             s->data_end = off + s->tracks;
802         }
803     }
804 
805     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
806         /* Image was not closed correctly. The check is mandatory */
807         s->header_unclean = true;
808         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
809             error_setg(errp, "parallels: Image was not closed correctly; "
810                        "cannot be opened read/write");
811             ret = -EACCES;
812             goto fail;
813         }
814     }
815 
816     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, &local_err);
817     if (local_err != NULL) {
818         goto fail_options;
819     }
820 
821     qemu_opts_absorb_qdict(opts, options, &local_err);
822     if (local_err != NULL) {
823         goto fail_options;
824     }
825 
826     s->prealloc_size =
827         qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
828     s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
829     buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
830     s->prealloc_mode = qapi_enum_parse(&prealloc_mode_lookup, buf,
831                                        PRL_PREALLOC_MODE_FALLOCATE,
832                                        &local_err);
833     g_free(buf);
834     if (local_err != NULL) {
835         goto fail_options;
836     }
837 
838     if (!bdrv_has_zero_init_truncate(bs->file->bs)) {
839         s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
840     }
841 
842     if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
843         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
844         ret = parallels_update_header(bs);
845         if (ret < 0) {
846             goto fail;
847         }
848     }
849 
850     s->bat_dirty_block = 4 * qemu_real_host_page_size;
851     s->bat_dirty_bmap =
852         bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
853 
854     /* Disable migration until bdrv_invalidate_cache method is added */
855     error_setg(&s->migration_blocker, "The Parallels format used by node '%s' "
856                "does not support live migration",
857                bdrv_get_device_or_node_name(bs));
858     ret = migrate_add_blocker(s->migration_blocker, &local_err);
859     if (local_err) {
860         error_propagate(errp, local_err);
861         error_free(s->migration_blocker);
862         goto fail;
863     }
864     qemu_co_mutex_init(&s->lock);
865     return 0;
866 
867 fail_format:
868     error_setg(errp, "Image not in Parallels format");
869     ret = -EINVAL;
870 fail:
871     qemu_vfree(s->header);
872     return ret;
873 
874 fail_options:
875     error_propagate(errp, local_err);
876     ret = -EINVAL;
877     goto fail;
878 }
879 
880 
881 static void parallels_close(BlockDriverState *bs)
882 {
883     BDRVParallelsState *s = bs->opaque;
884 
885     if ((bs->open_flags & BDRV_O_RDWR) && !(bs->open_flags & BDRV_O_INACTIVE)) {
886         s->header->inuse = 0;
887         parallels_update_header(bs);
888 
889         /* errors are ignored, so we might as well pass exact=true */
890         bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS, true,
891                       PREALLOC_MODE_OFF, NULL);
892     }
893 
894     g_free(s->bat_dirty_bmap);
895     qemu_vfree(s->header);
896 
897     migrate_del_blocker(s->migration_blocker);
898     error_free(s->migration_blocker);
899 }
900 
901 static BlockDriver bdrv_parallels = {
902     .format_name	= "parallels",
903     .instance_size	= sizeof(BDRVParallelsState),
904     .bdrv_probe		= parallels_probe,
905     .bdrv_open		= parallels_open,
906     .bdrv_close		= parallels_close,
907     .bdrv_child_perm          = bdrv_format_default_perms,
908     .bdrv_co_block_status     = parallels_co_block_status,
909     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
910     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
911     .bdrv_co_readv  = parallels_co_readv,
912     .bdrv_co_writev = parallels_co_writev,
913     .supports_backing = true,
914     .bdrv_co_create      = parallels_co_create,
915     .bdrv_co_create_opts = parallels_co_create_opts,
916     .bdrv_co_check  = parallels_co_check,
917     .create_opts    = &parallels_create_opts,
918 };
919 
920 static void bdrv_parallels_init(void)
921 {
922     bdrv_register(&bdrv_parallels);
923 }
924 
925 block_init(bdrv_parallels_init);
926