xref: /openbmc/qemu/block/parallels.c (revision 09a274d8)
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                                 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         QEMUIOVector qiov;
224         struct iovec iov = {
225             .iov_len = nb_cow_bytes,
226             .iov_base = qemu_blockalign(bs, nb_cow_bytes)
227         };
228         qemu_iovec_init_external(&qiov, &iov, 1);
229 
230         ret = bdrv_co_preadv(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
231                              nb_cow_bytes, &qiov, 0);
232         if (ret < 0) {
233             qemu_vfree(iov.iov_base);
234             return ret;
235         }
236 
237         ret = bdrv_co_pwritev(bs->file, s->data_end * BDRV_SECTOR_SIZE,
238                               nb_cow_bytes, &qiov, 0);
239         qemu_vfree(iov.iov_base);
240         if (ret < 0) {
241             return ret;
242         }
243     }
244 
245     for (i = 0; i < to_allocate; i++) {
246         s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
247         s->data_end += s->tracks;
248         bitmap_set(s->bat_dirty_bmap,
249                    bat_entry_off(idx + i) / s->bat_dirty_block, 1);
250     }
251 
252     return bat2sect(s, idx) + sector_num % s->tracks;
253 }
254 
255 
256 static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
257 {
258     BDRVParallelsState *s = bs->opaque;
259     unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
260     unsigned long bit;
261 
262     qemu_co_mutex_lock(&s->lock);
263 
264     bit = find_first_bit(s->bat_dirty_bmap, size);
265     while (bit < size) {
266         uint32_t off = bit * s->bat_dirty_block;
267         uint32_t to_write = s->bat_dirty_block;
268         int ret;
269 
270         if (off + to_write > s->header_size) {
271             to_write = s->header_size - off;
272         }
273         ret = bdrv_pwrite(bs->file, off, (uint8_t *)s->header + off,
274                           to_write);
275         if (ret < 0) {
276             qemu_co_mutex_unlock(&s->lock);
277             return ret;
278         }
279         bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
280     }
281     bitmap_zero(s->bat_dirty_bmap, size);
282 
283     qemu_co_mutex_unlock(&s->lock);
284     return 0;
285 }
286 
287 
288 static int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
289                                                   bool want_zero,
290                                                   int64_t offset,
291                                                   int64_t bytes,
292                                                   int64_t *pnum,
293                                                   int64_t *map,
294                                                   BlockDriverState **file)
295 {
296     BDRVParallelsState *s = bs->opaque;
297     int count;
298 
299     assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
300     qemu_co_mutex_lock(&s->lock);
301     offset = block_status(s, offset >> BDRV_SECTOR_BITS,
302                           bytes >> BDRV_SECTOR_BITS, &count);
303     qemu_co_mutex_unlock(&s->lock);
304 
305     *pnum = count * BDRV_SECTOR_SIZE;
306     if (offset < 0) {
307         return 0;
308     }
309 
310     *map = offset * BDRV_SECTOR_SIZE;
311     *file = bs->file->bs;
312     return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
313 }
314 
315 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
316                                             int64_t sector_num, int nb_sectors,
317                                             QEMUIOVector *qiov, int flags)
318 {
319     BDRVParallelsState *s = bs->opaque;
320     uint64_t bytes_done = 0;
321     QEMUIOVector hd_qiov;
322     int ret = 0;
323 
324     assert(!flags);
325     qemu_iovec_init(&hd_qiov, qiov->niov);
326 
327     while (nb_sectors > 0) {
328         int64_t position;
329         int n, nbytes;
330 
331         qemu_co_mutex_lock(&s->lock);
332         position = allocate_clusters(bs, sector_num, nb_sectors, &n);
333         qemu_co_mutex_unlock(&s->lock);
334         if (position < 0) {
335             ret = (int)position;
336             break;
337         }
338 
339         nbytes = n << BDRV_SECTOR_BITS;
340 
341         qemu_iovec_reset(&hd_qiov);
342         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
343 
344         ret = bdrv_co_pwritev(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
345                               &hd_qiov, 0);
346         if (ret < 0) {
347             break;
348         }
349 
350         nb_sectors -= n;
351         sector_num += n;
352         bytes_done += nbytes;
353     }
354 
355     qemu_iovec_destroy(&hd_qiov);
356     return ret;
357 }
358 
359 static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
360         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
361 {
362     BDRVParallelsState *s = bs->opaque;
363     uint64_t bytes_done = 0;
364     QEMUIOVector hd_qiov;
365     int ret = 0;
366 
367     qemu_iovec_init(&hd_qiov, qiov->niov);
368 
369     while (nb_sectors > 0) {
370         int64_t position;
371         int n, nbytes;
372 
373         qemu_co_mutex_lock(&s->lock);
374         position = block_status(s, sector_num, nb_sectors, &n);
375         qemu_co_mutex_unlock(&s->lock);
376 
377         nbytes = n << BDRV_SECTOR_BITS;
378 
379         qemu_iovec_reset(&hd_qiov);
380         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
381 
382         if (position < 0) {
383             if (bs->backing) {
384                 ret = bdrv_co_preadv(bs->backing, sector_num * BDRV_SECTOR_SIZE,
385                                      nbytes, &hd_qiov, 0);
386                 if (ret < 0) {
387                     break;
388                 }
389             } else {
390                 qemu_iovec_memset(&hd_qiov, 0, 0, nbytes);
391             }
392         } else {
393             ret = bdrv_co_preadv(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
394                                  &hd_qiov, 0);
395             if (ret < 0) {
396                 break;
397             }
398         }
399 
400         nb_sectors -= n;
401         sector_num += n;
402         bytes_done += nbytes;
403     }
404 
405     qemu_iovec_destroy(&hd_qiov);
406     return ret;
407 }
408 
409 
410 static int coroutine_fn parallels_co_check(BlockDriverState *bs,
411                                            BdrvCheckResult *res,
412                                            BdrvCheckMode fix)
413 {
414     BDRVParallelsState *s = bs->opaque;
415     int64_t size, prev_off, high_off;
416     int ret;
417     uint32_t i;
418     bool flush_bat = false;
419     int cluster_size = s->tracks << BDRV_SECTOR_BITS;
420 
421     size = bdrv_getlength(bs->file->bs);
422     if (size < 0) {
423         res->check_errors++;
424         return size;
425     }
426 
427     qemu_co_mutex_lock(&s->lock);
428     if (s->header_unclean) {
429         fprintf(stderr, "%s image was not closed correctly\n",
430                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
431         res->corruptions++;
432         if (fix & BDRV_FIX_ERRORS) {
433             /* parallels_close will do the job right */
434             res->corruptions_fixed++;
435             s->header_unclean = false;
436         }
437     }
438 
439     res->bfi.total_clusters = s->bat_size;
440     res->bfi.compressed_clusters = 0; /* compression is not supported */
441 
442     high_off = 0;
443     prev_off = 0;
444     for (i = 0; i < s->bat_size; i++) {
445         int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
446         if (off == 0) {
447             prev_off = 0;
448             continue;
449         }
450 
451         /* cluster outside the image */
452         if (off > size) {
453             fprintf(stderr, "%s cluster %u is outside image\n",
454                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
455             res->corruptions++;
456             if (fix & BDRV_FIX_ERRORS) {
457                 prev_off = 0;
458                 s->bat_bitmap[i] = 0;
459                 res->corruptions_fixed++;
460                 flush_bat = true;
461                 continue;
462             }
463         }
464 
465         res->bfi.allocated_clusters++;
466         if (off > high_off) {
467             high_off = off;
468         }
469 
470         if (prev_off != 0 && (prev_off + cluster_size) != off) {
471             res->bfi.fragmented_clusters++;
472         }
473         prev_off = off;
474     }
475 
476     ret = 0;
477     if (flush_bat) {
478         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
479         if (ret < 0) {
480             res->check_errors++;
481             goto out;
482         }
483     }
484 
485     res->image_end_offset = high_off + cluster_size;
486     if (size > res->image_end_offset) {
487         int64_t count;
488         count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
489         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
490                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
491                 size - res->image_end_offset);
492         res->leaks += count;
493         if (fix & BDRV_FIX_LEAKS) {
494             Error *local_err = NULL;
495             ret = bdrv_truncate(bs->file, res->image_end_offset,
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(BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
563     ret = blk_insert_bs(blk, bs, errp);
564     if (ret < 0) {
565         goto out;
566     }
567     blk_set_allow_write_beyond_eof(blk, true);
568 
569     /* Create image format */
570     ret = blk_truncate(blk, 0, PREALLOC_MODE_OFF, errp);
571     if (ret < 0) {
572         goto out;
573     }
574 
575     bat_entries = DIV_ROUND_UP(total_size, cl_size);
576     bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
577     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
578 
579     memset(&header, 0, sizeof(header));
580     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
581     header.version = cpu_to_le32(HEADER_VERSION);
582     /* don't care much about geometry, it is not used on image level */
583     header.heads = cpu_to_le32(HEADS_NUMBER);
584     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE
585                                    / HEADS_NUMBER / SEC_IN_CYL);
586     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
587     header.bat_entries = cpu_to_le32(bat_entries);
588     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
589     header.data_off = cpu_to_le32(bat_sectors);
590 
591     /* write all the data */
592     memset(tmp, 0, sizeof(tmp));
593     memcpy(tmp, &header, sizeof(header));
594 
595     ret = blk_pwrite(blk, 0, tmp, BDRV_SECTOR_SIZE, 0);
596     if (ret < 0) {
597         goto exit;
598     }
599     ret = blk_pwrite_zeroes(blk, BDRV_SECTOR_SIZE,
600                             (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
601     if (ret < 0) {
602         goto exit;
603     }
604 
605     ret = 0;
606 out:
607     blk_unref(blk);
608     bdrv_unref(bs);
609     return ret;
610 
611 exit:
612     error_setg_errno(errp, -ret, "Failed to create Parallels image");
613     goto out;
614 }
615 
616 static int coroutine_fn parallels_co_create_opts(const char *filename,
617                                                  QemuOpts *opts,
618                                                  Error **errp)
619 {
620     BlockdevCreateOptions *create_options = NULL;
621     Error *local_err = NULL;
622     BlockDriverState *bs = NULL;
623     QDict *qdict;
624     Visitor *v;
625     int ret;
626 
627     static const QDictRenames opt_renames[] = {
628         { BLOCK_OPT_CLUSTER_SIZE,       "cluster-size" },
629         { NULL, NULL },
630     };
631 
632     /* Parse options and convert legacy syntax */
633     qdict = qemu_opts_to_qdict_filtered(opts, NULL, &parallels_create_opts,
634                                         true);
635 
636     if (!qdict_rename_keys(qdict, opt_renames, errp)) {
637         ret = -EINVAL;
638         goto done;
639     }
640 
641     /* Create and open the file (protocol layer) */
642     ret = bdrv_create_file(filename, opts, &local_err);
643     if (ret < 0) {
644         error_propagate(errp, local_err);
645         goto done;
646     }
647 
648     bs = bdrv_open(filename, NULL, NULL,
649                    BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
650     if (bs == NULL) {
651         ret = -EIO;
652         goto done;
653     }
654 
655     /* Now get the QAPI type BlockdevCreateOptions */
656     qdict_put_str(qdict, "driver", "parallels");
657     qdict_put_str(qdict, "file", bs->node_name);
658 
659     v = qobject_input_visitor_new_flat_confused(qdict, errp);
660     if (!v) {
661         ret = -EINVAL;
662         goto done;
663     }
664 
665     visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
666     visit_free(v);
667 
668     if (local_err) {
669         error_propagate(errp, local_err);
670         ret = -EINVAL;
671         goto done;
672     }
673 
674     /* Silently round up sizes */
675     create_options->u.parallels.size =
676         ROUND_UP(create_options->u.parallels.size, BDRV_SECTOR_SIZE);
677     create_options->u.parallels.cluster_size =
678         ROUND_UP(create_options->u.parallels.cluster_size, BDRV_SECTOR_SIZE);
679 
680     /* Create the Parallels image (format layer) */
681     ret = parallels_co_create(create_options, errp);
682     if (ret < 0) {
683         goto done;
684     }
685     ret = 0;
686 
687 done:
688     qobject_unref(qdict);
689     bdrv_unref(bs);
690     qapi_free_BlockdevCreateOptions(create_options);
691     return ret;
692 }
693 
694 
695 static int parallels_probe(const uint8_t *buf, int buf_size,
696                            const char *filename)
697 {
698     const ParallelsHeader *ph = (const void *)buf;
699 
700     if (buf_size < sizeof(ParallelsHeader)) {
701         return 0;
702     }
703 
704     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
705            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
706            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
707         return 100;
708     }
709 
710     return 0;
711 }
712 
713 static int parallels_update_header(BlockDriverState *bs)
714 {
715     BDRVParallelsState *s = bs->opaque;
716     unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
717                         sizeof(ParallelsHeader));
718 
719     if (size > s->header_size) {
720         size = s->header_size;
721     }
722     return bdrv_pwrite_sync(bs->file, 0, s->header, size);
723 }
724 
725 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
726                           Error **errp)
727 {
728     BDRVParallelsState *s = bs->opaque;
729     ParallelsHeader ph;
730     int ret, size, i;
731     QemuOpts *opts = NULL;
732     Error *local_err = NULL;
733     char *buf;
734 
735     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
736                                false, errp);
737     if (!bs->file) {
738         return -EINVAL;
739     }
740 
741     ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
742     if (ret < 0) {
743         goto fail;
744     }
745 
746     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
747 
748     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
749         goto fail_format;
750     }
751     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
752         s->off_multiplier = 1;
753         bs->total_sectors = 0xffffffff & bs->total_sectors;
754     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
755         s->off_multiplier = le32_to_cpu(ph.tracks);
756     } else {
757         goto fail_format;
758     }
759 
760     s->tracks = le32_to_cpu(ph.tracks);
761     if (s->tracks == 0) {
762         error_setg(errp, "Invalid image: Zero sectors per track");
763         ret = -EINVAL;
764         goto fail;
765     }
766     if (s->tracks > INT32_MAX/513) {
767         error_setg(errp, "Invalid image: Too big cluster");
768         ret = -EFBIG;
769         goto fail;
770     }
771 
772     s->bat_size = le32_to_cpu(ph.bat_entries);
773     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
774         error_setg(errp, "Catalog too large");
775         ret = -EFBIG;
776         goto fail;
777     }
778 
779     size = bat_entry_off(s->bat_size);
780     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
781     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
782     if (s->header == NULL) {
783         ret = -ENOMEM;
784         goto fail;
785     }
786     s->data_end = le32_to_cpu(ph.data_off);
787     if (s->data_end == 0) {
788         s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
789     }
790     if (s->data_end < s->header_size) {
791         /* there is not enough unused space to fit to block align between BAT
792            and actual data. We can't avoid read-modify-write... */
793         s->header_size = size;
794     }
795 
796     ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
797     if (ret < 0) {
798         goto fail;
799     }
800     s->bat_bitmap = (uint32_t *)(s->header + 1);
801 
802     for (i = 0; i < s->bat_size; i++) {
803         int64_t off = bat2sect(s, i);
804         if (off >= s->data_end) {
805             s->data_end = off + s->tracks;
806         }
807     }
808 
809     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
810         /* Image was not closed correctly. The check is mandatory */
811         s->header_unclean = true;
812         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
813             error_setg(errp, "parallels: Image was not closed correctly; "
814                        "cannot be opened read/write");
815             ret = -EACCES;
816             goto fail;
817         }
818     }
819 
820     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, &local_err);
821     if (local_err != NULL) {
822         goto fail_options;
823     }
824 
825     qemu_opts_absorb_qdict(opts, options, &local_err);
826     if (local_err != NULL) {
827         goto fail_options;
828     }
829 
830     s->prealloc_size =
831         qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
832     s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
833     buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
834     s->prealloc_mode = qapi_enum_parse(&prealloc_mode_lookup, buf,
835                                        PRL_PREALLOC_MODE_FALLOCATE,
836                                        &local_err);
837     g_free(buf);
838     if (local_err != NULL) {
839         goto fail_options;
840     }
841 
842     if (!bdrv_has_zero_init(bs->file->bs)) {
843         s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
844     }
845 
846     if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
847         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
848         ret = parallels_update_header(bs);
849         if (ret < 0) {
850             goto fail;
851         }
852     }
853 
854     s->bat_dirty_block = 4 * getpagesize();
855     s->bat_dirty_bmap =
856         bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
857 
858     /* Disable migration until bdrv_invalidate_cache method is added */
859     error_setg(&s->migration_blocker, "The Parallels format used by node '%s' "
860                "does not support live migration",
861                bdrv_get_device_or_node_name(bs));
862     ret = migrate_add_blocker(s->migration_blocker, &local_err);
863     if (local_err) {
864         error_propagate(errp, local_err);
865         error_free(s->migration_blocker);
866         goto fail;
867     }
868     qemu_co_mutex_init(&s->lock);
869     return 0;
870 
871 fail_format:
872     error_setg(errp, "Image not in Parallels format");
873     ret = -EINVAL;
874 fail:
875     qemu_vfree(s->header);
876     return ret;
877 
878 fail_options:
879     error_propagate(errp, local_err);
880     ret = -EINVAL;
881     goto fail;
882 }
883 
884 
885 static void parallels_close(BlockDriverState *bs)
886 {
887     BDRVParallelsState *s = bs->opaque;
888 
889     if ((bs->open_flags & BDRV_O_RDWR) && !(bs->open_flags & BDRV_O_INACTIVE)) {
890         s->header->inuse = 0;
891         parallels_update_header(bs);
892         bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS,
893                       PREALLOC_MODE_OFF, NULL);
894     }
895 
896     g_free(s->bat_dirty_bmap);
897     qemu_vfree(s->header);
898 
899     migrate_del_blocker(s->migration_blocker);
900     error_free(s->migration_blocker);
901 }
902 
903 static BlockDriver bdrv_parallels = {
904     .format_name	= "parallels",
905     .instance_size	= sizeof(BDRVParallelsState),
906     .bdrv_probe		= parallels_probe,
907     .bdrv_open		= parallels_open,
908     .bdrv_close		= parallels_close,
909     .bdrv_child_perm          = bdrv_format_default_perms,
910     .bdrv_co_block_status     = parallels_co_block_status,
911     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
912     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
913     .bdrv_co_readv  = parallels_co_readv,
914     .bdrv_co_writev = parallels_co_writev,
915     .supports_backing = true,
916     .bdrv_co_create      = parallels_co_create,
917     .bdrv_co_create_opts = parallels_co_create_opts,
918     .bdrv_co_check  = parallels_co_check,
919     .create_opts    = &parallels_create_opts,
920 };
921 
922 static void bdrv_parallels_init(void)
923 {
924     bdrv_register(&bdrv_parallels);
925 }
926 
927 block_init(bdrv_parallels_init);
928