xref: /openbmc/qemu/block/parallels.c (revision 53c7c924)
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 "qemu/error-report.h"
33 #include "qapi/error.h"
34 #include "block/block_int.h"
35 #include "block/qdict.h"
36 #include "sysemu/block-backend.h"
37 #include "qemu/module.h"
38 #include "qemu/option.h"
39 #include "qapi/qmp/qdict.h"
40 #include "qapi/qobject-input-visitor.h"
41 #include "qapi/qapi-visit-block-core.h"
42 #include "qemu/bswap.h"
43 #include "qemu/bitmap.h"
44 #include "qemu/memalign.h"
45 #include "migration/blocker.h"
46 #include "parallels.h"
47 
48 /**************************************************************/
49 
50 #define HEADER_MAGIC "WithoutFreeSpace"
51 #define HEADER_MAGIC2 "WithouFreSpacExt"
52 #define HEADER_VERSION 2
53 #define HEADER_INUSE_MAGIC  (0x746F6E59)
54 #define MAX_PARALLELS_IMAGE_FACTOR (1ull << 32)
55 
56 static QEnumLookup prealloc_mode_lookup = {
57     .array = (const char *const[]) {
58         "falloc",
59         "truncate",
60     },
61     .size = PRL_PREALLOC_MODE__MAX
62 };
63 
64 #define PARALLELS_OPT_PREALLOC_MODE     "prealloc-mode"
65 #define PARALLELS_OPT_PREALLOC_SIZE     "prealloc-size"
66 
67 static QemuOptsList parallels_runtime_opts = {
68     .name = "parallels",
69     .head = QTAILQ_HEAD_INITIALIZER(parallels_runtime_opts.head),
70     .desc = {
71         {
72             .name = PARALLELS_OPT_PREALLOC_SIZE,
73             .type = QEMU_OPT_SIZE,
74             .help = "Preallocation size on image expansion",
75             .def_value_str = "128M",
76         },
77         {
78             .name = PARALLELS_OPT_PREALLOC_MODE,
79             .type = QEMU_OPT_STRING,
80             .help = "Preallocation mode on image expansion "
81                     "(allowed values: falloc, truncate)",
82             .def_value_str = "falloc",
83         },
84         { /* end of list */ },
85     },
86 };
87 
88 static QemuOptsList parallels_create_opts = {
89     .name = "parallels-create-opts",
90     .head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
91     .desc = {
92         {
93             .name = BLOCK_OPT_SIZE,
94             .type = QEMU_OPT_SIZE,
95             .help = "Virtual disk size",
96         },
97         {
98             .name = BLOCK_OPT_CLUSTER_SIZE,
99             .type = QEMU_OPT_SIZE,
100             .help = "Parallels image cluster size",
101             .def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
102         },
103         { /* end of list */ }
104     }
105 };
106 
107 
108 static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx)
109 {
110     return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier;
111 }
112 
113 static uint32_t bat_entry_off(uint32_t idx)
114 {
115     return sizeof(ParallelsHeader) + sizeof(uint32_t) * idx;
116 }
117 
118 static int64_t seek_to_sector(BDRVParallelsState *s, int64_t sector_num)
119 {
120     uint32_t index, offset;
121 
122     index = sector_num / s->tracks;
123     offset = sector_num % s->tracks;
124 
125     /* not allocated */
126     if ((index >= s->bat_size) || (s->bat_bitmap[index] == 0)) {
127         return -1;
128     }
129     return bat2sect(s, index) + offset;
130 }
131 
132 static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
133         int nb_sectors)
134 {
135     int ret = s->tracks - sector_num % s->tracks;
136     return MIN(nb_sectors, ret);
137 }
138 
139 static int64_t block_status(BDRVParallelsState *s, int64_t sector_num,
140                             int nb_sectors, int *pnum)
141 {
142     int64_t start_off = -2, prev_end_off = -2;
143 
144     *pnum = 0;
145     while (nb_sectors > 0 || start_off == -2) {
146         int64_t offset = seek_to_sector(s, sector_num);
147         int to_end;
148 
149         if (start_off == -2) {
150             start_off = offset;
151             prev_end_off = offset;
152         } else if (offset != prev_end_off) {
153             break;
154         }
155 
156         to_end = cluster_remainder(s, sector_num, nb_sectors);
157         nb_sectors -= to_end;
158         sector_num += to_end;
159         *pnum += to_end;
160 
161         if (offset > 0) {
162             prev_end_off += to_end;
163         }
164     }
165     return start_off;
166 }
167 
168 static void parallels_set_bat_entry(BDRVParallelsState *s,
169                                     uint32_t index, uint32_t offset)
170 {
171     s->bat_bitmap[index] = cpu_to_le32(offset);
172     bitmap_set(s->bat_dirty_bmap, bat_entry_off(index) / s->bat_dirty_block, 1);
173 }
174 
175 static int64_t coroutine_fn GRAPH_RDLOCK
176 allocate_clusters(BlockDriverState *bs, int64_t sector_num,
177                   int nb_sectors, int *pnum)
178 {
179     int ret = 0;
180     BDRVParallelsState *s = bs->opaque;
181     int64_t pos, space, idx, to_allocate, i, len;
182 
183     pos = block_status(s, sector_num, nb_sectors, pnum);
184     if (pos > 0) {
185         return pos;
186     }
187 
188     idx = sector_num / s->tracks;
189     to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
190 
191     /* This function is called only by parallels_co_writev(), which will never
192      * pass a sector_num at or beyond the end of the image (because the block
193      * layer never passes such a sector_num to that function). Therefore, idx
194      * is always below s->bat_size.
195      * block_status() will limit *pnum so that sector_num + *pnum will not
196      * exceed the image end. Therefore, idx + to_allocate cannot exceed
197      * s->bat_size.
198      * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
199      * will always fit into a uint32_t. */
200     assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
201 
202     space = to_allocate * s->tracks;
203     len = bdrv_co_getlength(bs->file->bs);
204     if (len < 0) {
205         return len;
206     }
207     if (s->data_end + space > (len >> BDRV_SECTOR_BITS)) {
208         space += s->prealloc_size;
209         /*
210          * We require the expanded size to read back as zero. If the
211          * user permitted truncation, we try that; but if it fails, we
212          * force the safer-but-slower fallocate.
213          */
214         if (s->prealloc_mode == PRL_PREALLOC_MODE_TRUNCATE) {
215             ret = bdrv_co_truncate(bs->file,
216                                    (s->data_end + space) << BDRV_SECTOR_BITS,
217                                    false, PREALLOC_MODE_OFF,
218                                    BDRV_REQ_ZERO_WRITE, NULL);
219             if (ret == -ENOTSUP) {
220                 s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
221             }
222         }
223         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
224             ret = bdrv_co_pwrite_zeroes(bs->file,
225                                         s->data_end << BDRV_SECTOR_BITS,
226                                         space << BDRV_SECTOR_BITS, 0);
227         }
228         if (ret < 0) {
229             return ret;
230         }
231     }
232 
233     /* Try to read from backing to fill empty clusters
234      * FIXME: 1. previous write_zeroes may be redundant
235      *        2. most of data we read from backing will be rewritten by
236      *           parallels_co_writev. On aligned-to-cluster write we do not need
237      *           this read at all.
238      *        3. it would be good to combine write of data from backing and new
239      *           data into one write call */
240     if (bs->backing) {
241         int64_t nb_cow_sectors = to_allocate * s->tracks;
242         int64_t nb_cow_bytes = nb_cow_sectors << BDRV_SECTOR_BITS;
243         void *buf = qemu_blockalign(bs, nb_cow_bytes);
244 
245         ret = bdrv_co_pread(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
246                             nb_cow_bytes, buf, 0);
247         if (ret < 0) {
248             qemu_vfree(buf);
249             return ret;
250         }
251 
252         ret = bdrv_co_pwrite(bs->file, s->data_end * BDRV_SECTOR_SIZE,
253                              nb_cow_bytes, buf, 0);
254         qemu_vfree(buf);
255         if (ret < 0) {
256             return ret;
257         }
258     }
259 
260     for (i = 0; i < to_allocate; i++) {
261         parallels_set_bat_entry(s, idx + i, s->data_end / s->off_multiplier);
262         s->data_end += s->tracks;
263     }
264 
265     return bat2sect(s, idx) + sector_num % s->tracks;
266 }
267 
268 
269 static int coroutine_fn GRAPH_RDLOCK
270 parallels_co_flush_to_os(BlockDriverState *bs)
271 {
272     BDRVParallelsState *s = bs->opaque;
273     unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
274     unsigned long bit;
275 
276     qemu_co_mutex_lock(&s->lock);
277 
278     bit = find_first_bit(s->bat_dirty_bmap, size);
279     while (bit < size) {
280         uint32_t off = bit * s->bat_dirty_block;
281         uint32_t to_write = s->bat_dirty_block;
282         int ret;
283 
284         if (off + to_write > s->header_size) {
285             to_write = s->header_size - off;
286         }
287         ret = bdrv_co_pwrite(bs->file, off, to_write,
288                              (uint8_t *)s->header + off, 0);
289         if (ret < 0) {
290             qemu_co_mutex_unlock(&s->lock);
291             return ret;
292         }
293         bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
294     }
295     bitmap_zero(s->bat_dirty_bmap, size);
296 
297     qemu_co_mutex_unlock(&s->lock);
298     return 0;
299 }
300 
301 
302 static int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
303                                                   bool want_zero,
304                                                   int64_t offset,
305                                                   int64_t bytes,
306                                                   int64_t *pnum,
307                                                   int64_t *map,
308                                                   BlockDriverState **file)
309 {
310     BDRVParallelsState *s = bs->opaque;
311     int count;
312 
313     assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
314     qemu_co_mutex_lock(&s->lock);
315     offset = block_status(s, offset >> BDRV_SECTOR_BITS,
316                           bytes >> BDRV_SECTOR_BITS, &count);
317     qemu_co_mutex_unlock(&s->lock);
318 
319     *pnum = count * BDRV_SECTOR_SIZE;
320     if (offset < 0) {
321         return 0;
322     }
323 
324     *map = offset * BDRV_SECTOR_SIZE;
325     *file = bs->file->bs;
326     return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
327 }
328 
329 static int coroutine_fn GRAPH_RDLOCK
330 parallels_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
331                     QEMUIOVector *qiov, int flags)
332 {
333     BDRVParallelsState *s = bs->opaque;
334     uint64_t bytes_done = 0;
335     QEMUIOVector hd_qiov;
336     int ret = 0;
337 
338     qemu_iovec_init(&hd_qiov, qiov->niov);
339 
340     while (nb_sectors > 0) {
341         int64_t position;
342         int n, nbytes;
343 
344         qemu_co_mutex_lock(&s->lock);
345         position = allocate_clusters(bs, sector_num, nb_sectors, &n);
346         qemu_co_mutex_unlock(&s->lock);
347         if (position < 0) {
348             ret = (int)position;
349             break;
350         }
351 
352         nbytes = n << BDRV_SECTOR_BITS;
353 
354         qemu_iovec_reset(&hd_qiov);
355         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
356 
357         ret = bdrv_co_pwritev(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
358                               &hd_qiov, 0);
359         if (ret < 0) {
360             break;
361         }
362 
363         nb_sectors -= n;
364         sector_num += n;
365         bytes_done += nbytes;
366     }
367 
368     qemu_iovec_destroy(&hd_qiov);
369     return ret;
370 }
371 
372 static int coroutine_fn GRAPH_RDLOCK
373 parallels_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
374                    QEMUIOVector *qiov)
375 {
376     BDRVParallelsState *s = bs->opaque;
377     uint64_t bytes_done = 0;
378     QEMUIOVector hd_qiov;
379     int ret = 0;
380 
381     qemu_iovec_init(&hd_qiov, qiov->niov);
382 
383     while (nb_sectors > 0) {
384         int64_t position;
385         int n, nbytes;
386 
387         qemu_co_mutex_lock(&s->lock);
388         position = block_status(s, sector_num, nb_sectors, &n);
389         qemu_co_mutex_unlock(&s->lock);
390 
391         nbytes = n << BDRV_SECTOR_BITS;
392 
393         qemu_iovec_reset(&hd_qiov);
394         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
395 
396         if (position < 0) {
397             if (bs->backing) {
398                 ret = bdrv_co_preadv(bs->backing, sector_num * BDRV_SECTOR_SIZE,
399                                      nbytes, &hd_qiov, 0);
400                 if (ret < 0) {
401                     break;
402                 }
403             } else {
404                 qemu_iovec_memset(&hd_qiov, 0, 0, nbytes);
405             }
406         } else {
407             ret = bdrv_co_preadv(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
408                                  &hd_qiov, 0);
409             if (ret < 0) {
410                 break;
411             }
412         }
413 
414         nb_sectors -= n;
415         sector_num += n;
416         bytes_done += nbytes;
417     }
418 
419     qemu_iovec_destroy(&hd_qiov);
420     return ret;
421 }
422 
423 static void parallels_check_unclean(BlockDriverState *bs,
424                                     BdrvCheckResult *res,
425                                     BdrvCheckMode fix)
426 {
427     BDRVParallelsState *s = bs->opaque;
428 
429     if (!s->header_unclean) {
430         return;
431     }
432 
433     fprintf(stderr, "%s image was not closed correctly\n",
434             fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
435     res->corruptions++;
436     if (fix & BDRV_FIX_ERRORS) {
437         /* parallels_close will do the job right */
438         res->corruptions_fixed++;
439         s->header_unclean = false;
440     }
441 }
442 
443 static int coroutine_fn GRAPH_RDLOCK
444 parallels_check_outside_image(BlockDriverState *bs, BdrvCheckResult *res,
445                               BdrvCheckMode fix)
446 {
447     BDRVParallelsState *s = bs->opaque;
448     uint32_t i;
449     int64_t off, high_off, size;
450 
451     size = bdrv_co_getlength(bs->file->bs);
452     if (size < 0) {
453         res->check_errors++;
454         return size;
455     }
456 
457     high_off = 0;
458     for (i = 0; i < s->bat_size; i++) {
459         off = bat2sect(s, i) << BDRV_SECTOR_BITS;
460         if (off + s->cluster_size > size) {
461             fprintf(stderr, "%s cluster %u is outside image\n",
462                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
463             res->corruptions++;
464             if (fix & BDRV_FIX_ERRORS) {
465                 parallels_set_bat_entry(s, i, 0);
466                 res->corruptions_fixed++;
467             }
468             continue;
469         }
470         if (high_off < off) {
471             high_off = off;
472         }
473     }
474 
475     if (high_off == 0) {
476         res->image_end_offset = s->data_end << BDRV_SECTOR_BITS;
477     } else {
478         res->image_end_offset = high_off + s->cluster_size;
479         s->data_end = res->image_end_offset >> BDRV_SECTOR_BITS;
480     }
481 
482     return 0;
483 }
484 
485 static int coroutine_fn GRAPH_RDLOCK
486 parallels_check_leak(BlockDriverState *bs, BdrvCheckResult *res,
487                      BdrvCheckMode fix)
488 {
489     BDRVParallelsState *s = bs->opaque;
490     int64_t size;
491     int ret;
492 
493     size = bdrv_getlength(bs->file->bs);
494     if (size < 0) {
495         res->check_errors++;
496         return size;
497     }
498 
499     if (size > res->image_end_offset) {
500         int64_t count;
501         count = DIV_ROUND_UP(size - res->image_end_offset, s->cluster_size);
502         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
503                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
504                 size - res->image_end_offset);
505         res->leaks += count;
506         if (fix & BDRV_FIX_LEAKS) {
507             Error *local_err = NULL;
508 
509             /*
510              * In order to really repair the image, we must shrink it.
511              * That means we have to pass exact=true.
512              */
513             ret = bdrv_co_truncate(bs->file, res->image_end_offset, true,
514                                    PREALLOC_MODE_OFF, 0, &local_err);
515             if (ret < 0) {
516                 error_report_err(local_err);
517                 res->check_errors++;
518                 return ret;
519             }
520             res->leaks_fixed += count;
521         }
522     }
523 
524     return 0;
525 }
526 
527 static void parallels_collect_statistics(BlockDriverState *bs,
528                                          BdrvCheckResult *res,
529                                          BdrvCheckMode fix)
530 {
531     BDRVParallelsState *s = bs->opaque;
532     int64_t off, prev_off;
533     uint32_t i;
534 
535     res->bfi.total_clusters = s->bat_size;
536     res->bfi.compressed_clusters = 0; /* compression is not supported */
537 
538     prev_off = 0;
539     for (i = 0; i < s->bat_size; i++) {
540         off = bat2sect(s, i) << BDRV_SECTOR_BITS;
541         /*
542          * If BDRV_FIX_ERRORS is not set, out-of-image BAT entries were not
543          * fixed. Skip not allocated and out-of-image BAT entries.
544          */
545         if (off == 0 || off + s->cluster_size > res->image_end_offset) {
546             prev_off = 0;
547             continue;
548         }
549 
550         if (prev_off != 0 && (prev_off + s->cluster_size) != off) {
551             res->bfi.fragmented_clusters++;
552         }
553         prev_off = off;
554         res->bfi.allocated_clusters++;
555     }
556 }
557 
558 static int coroutine_fn GRAPH_RDLOCK
559 parallels_co_check(BlockDriverState *bs, BdrvCheckResult *res,
560                    BdrvCheckMode fix)
561 {
562     BDRVParallelsState *s = bs->opaque;
563     int ret;
564 
565     WITH_QEMU_LOCK_GUARD(&s->lock) {
566         parallels_check_unclean(bs, res, fix);
567 
568         ret = parallels_check_outside_image(bs, res, fix);
569         if (ret < 0) {
570             return ret;
571         }
572 
573         ret = parallels_check_leak(bs, res, fix);
574         if (ret < 0) {
575             return ret;
576         }
577 
578         parallels_collect_statistics(bs, res, fix);
579     }
580 
581     ret = bdrv_co_flush(bs);
582     if (ret < 0) {
583         res->check_errors++;
584     }
585 
586     return ret;
587 }
588 
589 
590 static int coroutine_fn GRAPH_UNLOCKED
591 parallels_co_create(BlockdevCreateOptions* opts, Error **errp)
592 {
593     BlockdevCreateOptionsParallels *parallels_opts;
594     BlockDriverState *bs;
595     BlockBackend *blk;
596     int64_t total_size, cl_size;
597     uint32_t bat_entries, bat_sectors;
598     ParallelsHeader header;
599     uint8_t tmp[BDRV_SECTOR_SIZE];
600     int ret;
601 
602     assert(opts->driver == BLOCKDEV_DRIVER_PARALLELS);
603     parallels_opts = &opts->u.parallels;
604 
605     /* Sanity checks */
606     total_size = parallels_opts->size;
607 
608     if (parallels_opts->has_cluster_size) {
609         cl_size = parallels_opts->cluster_size;
610     } else {
611         cl_size = DEFAULT_CLUSTER_SIZE;
612     }
613 
614     /* XXX What is the real limit here? This is an insanely large maximum. */
615     if (cl_size >= INT64_MAX / MAX_PARALLELS_IMAGE_FACTOR) {
616         error_setg(errp, "Cluster size is too large");
617         return -EINVAL;
618     }
619     if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
620         error_setg(errp, "Image size is too large for this cluster size");
621         return -E2BIG;
622     }
623 
624     if (!QEMU_IS_ALIGNED(total_size, BDRV_SECTOR_SIZE)) {
625         error_setg(errp, "Image size must be a multiple of 512 bytes");
626         return -EINVAL;
627     }
628 
629     if (!QEMU_IS_ALIGNED(cl_size, BDRV_SECTOR_SIZE)) {
630         error_setg(errp, "Cluster size must be a multiple of 512 bytes");
631         return -EINVAL;
632     }
633 
634     /* Create BlockBackend to write to the image */
635     bs = bdrv_co_open_blockdev_ref(parallels_opts->file, errp);
636     if (bs == NULL) {
637         return -EIO;
638     }
639 
640     blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
641                              errp);
642     if (!blk) {
643         ret = -EPERM;
644         goto out;
645     }
646     blk_set_allow_write_beyond_eof(blk, true);
647 
648     /* Create image format */
649     bat_entries = DIV_ROUND_UP(total_size, cl_size);
650     bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
651     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
652 
653     memset(&header, 0, sizeof(header));
654     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
655     header.version = cpu_to_le32(HEADER_VERSION);
656     /* don't care much about geometry, it is not used on image level */
657     header.heads = cpu_to_le32(HEADS_NUMBER);
658     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE
659                                    / HEADS_NUMBER / SEC_IN_CYL);
660     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
661     header.bat_entries = cpu_to_le32(bat_entries);
662     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
663     header.data_off = cpu_to_le32(bat_sectors);
664 
665     /* write all the data */
666     memset(tmp, 0, sizeof(tmp));
667     memcpy(tmp, &header, sizeof(header));
668 
669     ret = blk_co_pwrite(blk, 0, BDRV_SECTOR_SIZE, tmp, 0);
670     if (ret < 0) {
671         goto exit;
672     }
673     ret = blk_co_pwrite_zeroes(blk, BDRV_SECTOR_SIZE,
674                                (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
675     if (ret < 0) {
676         goto exit;
677     }
678 
679     ret = 0;
680 out:
681     blk_co_unref(blk);
682     bdrv_co_unref(bs);
683     return ret;
684 
685 exit:
686     error_setg_errno(errp, -ret, "Failed to create Parallels image");
687     goto out;
688 }
689 
690 static int coroutine_fn GRAPH_UNLOCKED
691 parallels_co_create_opts(BlockDriver *drv, const char *filename,
692                          QemuOpts *opts, Error **errp)
693 {
694     BlockdevCreateOptions *create_options = NULL;
695     BlockDriverState *bs = NULL;
696     QDict *qdict;
697     Visitor *v;
698     int ret;
699 
700     static const QDictRenames opt_renames[] = {
701         { BLOCK_OPT_CLUSTER_SIZE,       "cluster-size" },
702         { NULL, NULL },
703     };
704 
705     /* Parse options and convert legacy syntax */
706     qdict = qemu_opts_to_qdict_filtered(opts, NULL, &parallels_create_opts,
707                                         true);
708 
709     if (!qdict_rename_keys(qdict, opt_renames, errp)) {
710         ret = -EINVAL;
711         goto done;
712     }
713 
714     /* Create and open the file (protocol layer) */
715     ret = bdrv_co_create_file(filename, opts, errp);
716     if (ret < 0) {
717         goto done;
718     }
719 
720     bs = bdrv_co_open(filename, NULL, NULL,
721                       BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
722     if (bs == NULL) {
723         ret = -EIO;
724         goto done;
725     }
726 
727     /* Now get the QAPI type BlockdevCreateOptions */
728     qdict_put_str(qdict, "driver", "parallels");
729     qdict_put_str(qdict, "file", bs->node_name);
730 
731     v = qobject_input_visitor_new_flat_confused(qdict, errp);
732     if (!v) {
733         ret = -EINVAL;
734         goto done;
735     }
736 
737     visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
738     visit_free(v);
739     if (!create_options) {
740         ret = -EINVAL;
741         goto done;
742     }
743 
744     /* Silently round up sizes */
745     create_options->u.parallels.size =
746         ROUND_UP(create_options->u.parallels.size, BDRV_SECTOR_SIZE);
747     create_options->u.parallels.cluster_size =
748         ROUND_UP(create_options->u.parallels.cluster_size, BDRV_SECTOR_SIZE);
749 
750     /* Create the Parallels image (format layer) */
751     ret = parallels_co_create(create_options, errp);
752     if (ret < 0) {
753         goto done;
754     }
755     ret = 0;
756 
757 done:
758     qobject_unref(qdict);
759     bdrv_co_unref(bs);
760     qapi_free_BlockdevCreateOptions(create_options);
761     return ret;
762 }
763 
764 
765 static int parallels_probe(const uint8_t *buf, int buf_size,
766                            const char *filename)
767 {
768     const ParallelsHeader *ph = (const void *)buf;
769 
770     if (buf_size < sizeof(ParallelsHeader)) {
771         return 0;
772     }
773 
774     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
775            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
776            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
777         return 100;
778     }
779 
780     return 0;
781 }
782 
783 static int parallels_update_header(BlockDriverState *bs)
784 {
785     BDRVParallelsState *s = bs->opaque;
786     unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
787                         sizeof(ParallelsHeader));
788 
789     if (size > s->header_size) {
790         size = s->header_size;
791     }
792     return bdrv_pwrite_sync(bs->file, 0, size, s->header, 0);
793 }
794 
795 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
796                           Error **errp)
797 {
798     BDRVParallelsState *s = bs->opaque;
799     ParallelsHeader ph;
800     int ret, size, i;
801     int64_t file_nb_sectors;
802     QemuOpts *opts = NULL;
803     Error *local_err = NULL;
804     char *buf;
805 
806     ret = bdrv_open_file_child(NULL, options, "file", bs, errp);
807     if (ret < 0) {
808         return ret;
809     }
810 
811     file_nb_sectors = bdrv_nb_sectors(bs->file->bs);
812     if (file_nb_sectors < 0) {
813         return -EINVAL;
814     }
815 
816     ret = bdrv_pread(bs->file, 0, sizeof(ph), &ph, 0);
817     if (ret < 0) {
818         goto fail;
819     }
820 
821     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
822 
823     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
824         goto fail_format;
825     }
826     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
827         s->off_multiplier = 1;
828         bs->total_sectors = 0xffffffff & bs->total_sectors;
829     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
830         s->off_multiplier = le32_to_cpu(ph.tracks);
831     } else {
832         goto fail_format;
833     }
834 
835     s->tracks = le32_to_cpu(ph.tracks);
836     if (s->tracks == 0) {
837         error_setg(errp, "Invalid image: Zero sectors per track");
838         ret = -EINVAL;
839         goto fail;
840     }
841     if (s->tracks > INT32_MAX/513) {
842         error_setg(errp, "Invalid image: Too big cluster");
843         ret = -EFBIG;
844         goto fail;
845     }
846     s->cluster_size = s->tracks << BDRV_SECTOR_BITS;
847 
848     s->bat_size = le32_to_cpu(ph.bat_entries);
849     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
850         error_setg(errp, "Catalog too large");
851         ret = -EFBIG;
852         goto fail;
853     }
854 
855     size = bat_entry_off(s->bat_size);
856     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
857     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
858     if (s->header == NULL) {
859         ret = -ENOMEM;
860         goto fail;
861     }
862     s->data_end = le32_to_cpu(ph.data_off);
863     if (s->data_end == 0) {
864         s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
865     }
866     if (s->data_end < s->header_size) {
867         /* there is not enough unused space to fit to block align between BAT
868            and actual data. We can't avoid read-modify-write... */
869         s->header_size = size;
870     }
871 
872     ret = bdrv_pread(bs->file, 0, s->header_size, s->header, 0);
873     if (ret < 0) {
874         goto fail;
875     }
876     s->bat_bitmap = (uint32_t *)(s->header + 1);
877 
878     for (i = 0; i < s->bat_size; i++) {
879         int64_t off = bat2sect(s, i);
880         if (off >= file_nb_sectors) {
881             if (flags & BDRV_O_CHECK) {
882                 continue;
883             }
884             error_setg(errp, "parallels: Offset %" PRIi64 " in BAT[%d] entry "
885                        "is larger than file size (%" PRIi64 ")",
886                        off << BDRV_SECTOR_BITS, i,
887                        file_nb_sectors << BDRV_SECTOR_BITS);
888             ret = -EINVAL;
889             goto fail;
890         }
891         if (off >= s->data_end) {
892             s->data_end = off + s->tracks;
893         }
894     }
895 
896     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
897         /* Image was not closed correctly. The check is mandatory */
898         s->header_unclean = true;
899         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
900             error_setg(errp, "parallels: Image was not closed correctly; "
901                        "cannot be opened read/write");
902             ret = -EACCES;
903             goto fail;
904         }
905     }
906 
907     opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, errp);
908     if (!opts) {
909         goto fail_options;
910     }
911 
912     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
913         goto fail_options;
914     }
915 
916     s->prealloc_size =
917         qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
918     s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
919     buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
920     /* prealloc_mode can be downgraded later during allocate_clusters */
921     s->prealloc_mode = qapi_enum_parse(&prealloc_mode_lookup, buf,
922                                        PRL_PREALLOC_MODE_FALLOCATE,
923                                        &local_err);
924     g_free(buf);
925     if (local_err != NULL) {
926         error_propagate(errp, local_err);
927         goto fail_options;
928     }
929 
930     if (ph.ext_off) {
931         if (flags & BDRV_O_RDWR) {
932             /*
933              * It's unsafe to open image RW if there is an extension (as we
934              * don't support it). But parallels driver in QEMU historically
935              * ignores the extension, so print warning and don't care.
936              */
937             warn_report("Format Extension ignored in RW mode");
938         } else {
939             ret = parallels_read_format_extension(
940                     bs, le64_to_cpu(ph.ext_off) << BDRV_SECTOR_BITS, errp);
941             if (ret < 0) {
942                 goto fail;
943             }
944         }
945     }
946 
947     if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
948         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
949         ret = parallels_update_header(bs);
950         if (ret < 0) {
951             goto fail;
952         }
953     }
954 
955     s->bat_dirty_block = 4 * qemu_real_host_page_size();
956     s->bat_dirty_bmap =
957         bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
958 
959     /* Disable migration until bdrv_activate method is added */
960     error_setg(&s->migration_blocker, "The Parallels format used by node '%s' "
961                "does not support live migration",
962                bdrv_get_device_or_node_name(bs));
963     ret = migrate_add_blocker(s->migration_blocker, errp);
964     if (ret < 0) {
965         error_free(s->migration_blocker);
966         goto fail;
967     }
968     qemu_co_mutex_init(&s->lock);
969     return 0;
970 
971 fail_format:
972     error_setg(errp, "Image not in Parallels format");
973 fail_options:
974     ret = -EINVAL;
975 fail:
976     qemu_vfree(s->header);
977     return ret;
978 }
979 
980 
981 static void parallels_close(BlockDriverState *bs)
982 {
983     BDRVParallelsState *s = bs->opaque;
984 
985     if ((bs->open_flags & BDRV_O_RDWR) && !(bs->open_flags & BDRV_O_INACTIVE)) {
986         s->header->inuse = 0;
987         parallels_update_header(bs);
988 
989         /* errors are ignored, so we might as well pass exact=true */
990         bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS, true,
991                       PREALLOC_MODE_OFF, 0, NULL);
992     }
993 
994     g_free(s->bat_dirty_bmap);
995     qemu_vfree(s->header);
996 
997     migrate_del_blocker(s->migration_blocker);
998     error_free(s->migration_blocker);
999 }
1000 
1001 static BlockDriver bdrv_parallels = {
1002     .format_name	= "parallels",
1003     .instance_size	= sizeof(BDRVParallelsState),
1004     .bdrv_probe		= parallels_probe,
1005     .bdrv_open		= parallels_open,
1006     .bdrv_close		= parallels_close,
1007     .bdrv_child_perm          = bdrv_default_perms,
1008     .bdrv_co_block_status     = parallels_co_block_status,
1009     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
1010     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
1011     .bdrv_co_readv  = parallels_co_readv,
1012     .bdrv_co_writev = parallels_co_writev,
1013     .is_format      = true,
1014     .supports_backing = true,
1015     .bdrv_co_create      = parallels_co_create,
1016     .bdrv_co_create_opts = parallels_co_create_opts,
1017     .bdrv_co_check  = parallels_co_check,
1018     .create_opts    = &parallels_create_opts,
1019 };
1020 
1021 static void bdrv_parallels_init(void)
1022 {
1023     bdrv_register(&bdrv_parallels);
1024 }
1025 
1026 block_init(bdrv_parallels_init);
1027