xref: /qemu/block/mirror.c (revision eee13dfe302833944d1176677d12a6ea421a94ea)
1893f7ebaSPaolo Bonzini /*
2893f7ebaSPaolo Bonzini  * Image mirroring
3893f7ebaSPaolo Bonzini  *
4893f7ebaSPaolo Bonzini  * Copyright Red Hat, Inc. 2012
5893f7ebaSPaolo Bonzini  *
6893f7ebaSPaolo Bonzini  * Authors:
7893f7ebaSPaolo Bonzini  *  Paolo Bonzini  <pbonzini@redhat.com>
8893f7ebaSPaolo Bonzini  *
9893f7ebaSPaolo Bonzini  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
10893f7ebaSPaolo Bonzini  * See the COPYING.LIB file in the top-level directory.
11893f7ebaSPaolo Bonzini  *
12893f7ebaSPaolo Bonzini  */
13893f7ebaSPaolo Bonzini 
14893f7ebaSPaolo Bonzini #include "trace.h"
15737e150eSPaolo Bonzini #include "block/blockjob.h"
16737e150eSPaolo Bonzini #include "block/block_int.h"
17893f7ebaSPaolo Bonzini #include "qemu/ratelimit.h"
18b812f671SPaolo Bonzini #include "qemu/bitmap.h"
19893f7ebaSPaolo Bonzini 
20893f7ebaSPaolo Bonzini #define SLICE_TIME 100000000ULL /* ns */
21893f7ebaSPaolo Bonzini 
22893f7ebaSPaolo Bonzini typedef struct MirrorBlockJob {
23893f7ebaSPaolo Bonzini     BlockJob common;
24893f7ebaSPaolo Bonzini     RateLimit limit;
25893f7ebaSPaolo Bonzini     BlockDriverState *target;
26893f7ebaSPaolo Bonzini     MirrorSyncMode mode;
27b952b558SPaolo Bonzini     BlockdevOnError on_source_error, on_target_error;
28d63ffd87SPaolo Bonzini     bool synced;
29d63ffd87SPaolo Bonzini     bool should_complete;
30893f7ebaSPaolo Bonzini     int64_t sector_num;
31*eee13dfeSPaolo Bonzini     int64_t granularity;
32b812f671SPaolo Bonzini     size_t buf_size;
33b812f671SPaolo Bonzini     unsigned long *cow_bitmap;
348f0720ecSPaolo Bonzini     HBitmapIter hbi;
35893f7ebaSPaolo Bonzini     uint8_t *buf;
36893f7ebaSPaolo Bonzini } MirrorBlockJob;
37893f7ebaSPaolo Bonzini 
38b952b558SPaolo Bonzini static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read,
39b952b558SPaolo Bonzini                                             int error)
40b952b558SPaolo Bonzini {
41b952b558SPaolo Bonzini     s->synced = false;
42b952b558SPaolo Bonzini     if (read) {
43b952b558SPaolo Bonzini         return block_job_error_action(&s->common, s->common.bs,
44b952b558SPaolo Bonzini                                       s->on_source_error, true, error);
45b952b558SPaolo Bonzini     } else {
46b952b558SPaolo Bonzini         return block_job_error_action(&s->common, s->target,
47b952b558SPaolo Bonzini                                       s->on_target_error, false, error);
48b952b558SPaolo Bonzini     }
49b952b558SPaolo Bonzini }
50b952b558SPaolo Bonzini 
51b952b558SPaolo Bonzini static int coroutine_fn mirror_iteration(MirrorBlockJob *s,
52b952b558SPaolo Bonzini                                          BlockErrorAction *p_action)
53893f7ebaSPaolo Bonzini {
54893f7ebaSPaolo Bonzini     BlockDriverState *source = s->common.bs;
55893f7ebaSPaolo Bonzini     BlockDriverState *target = s->target;
56893f7ebaSPaolo Bonzini     QEMUIOVector qiov;
57*eee13dfeSPaolo Bonzini     int ret, nb_sectors, sectors_per_chunk;
58b812f671SPaolo Bonzini     int64_t end, sector_num, chunk_num;
59893f7ebaSPaolo Bonzini     struct iovec iov;
60893f7ebaSPaolo Bonzini 
618f0720ecSPaolo Bonzini     s->sector_num = hbitmap_iter_next(&s->hbi);
628f0720ecSPaolo Bonzini     if (s->sector_num < 0) {
638f0720ecSPaolo Bonzini         bdrv_dirty_iter_init(source, &s->hbi);
648f0720ecSPaolo Bonzini         s->sector_num = hbitmap_iter_next(&s->hbi);
658f0720ecSPaolo Bonzini         trace_mirror_restart_iter(s, bdrv_get_dirty_count(source));
668f0720ecSPaolo Bonzini         assert(s->sector_num >= 0);
678f0720ecSPaolo Bonzini     }
688f0720ecSPaolo Bonzini 
69b812f671SPaolo Bonzini     /* If we have no backing file yet in the destination, and the cluster size
70b812f671SPaolo Bonzini      * is very large, we need to do COW ourselves.  The first time a cluster is
71b812f671SPaolo Bonzini      * copied, copy it entirely.
72b812f671SPaolo Bonzini      *
73*eee13dfeSPaolo Bonzini      * Because both the granularity and the cluster size are powers of two, the
74*eee13dfeSPaolo Bonzini      * number of sectors to copy cannot exceed one cluster.
75b812f671SPaolo Bonzini      */
76b812f671SPaolo Bonzini     sector_num = s->sector_num;
77*eee13dfeSPaolo Bonzini     sectors_per_chunk = nb_sectors = s->granularity >> BDRV_SECTOR_BITS;
78*eee13dfeSPaolo Bonzini     chunk_num = sector_num / sectors_per_chunk;
79b812f671SPaolo Bonzini     if (s->cow_bitmap && !test_bit(chunk_num, s->cow_bitmap)) {
80b812f671SPaolo Bonzini         trace_mirror_cow(s, sector_num);
81b812f671SPaolo Bonzini         bdrv_round_to_clusters(s->target,
82*eee13dfeSPaolo Bonzini                                sector_num, sectors_per_chunk,
83b812f671SPaolo Bonzini                                &sector_num, &nb_sectors);
84b812f671SPaolo Bonzini     }
85b812f671SPaolo Bonzini 
86893f7ebaSPaolo Bonzini     end = s->common.len >> BDRV_SECTOR_BITS;
87b812f671SPaolo Bonzini     nb_sectors = MIN(nb_sectors, end - sector_num);
88b812f671SPaolo Bonzini     bdrv_reset_dirty(source, sector_num, nb_sectors);
89893f7ebaSPaolo Bonzini 
90893f7ebaSPaolo Bonzini     /* Copy the dirty cluster.  */
91893f7ebaSPaolo Bonzini     iov.iov_base = s->buf;
92893f7ebaSPaolo Bonzini     iov.iov_len  = nb_sectors * 512;
93893f7ebaSPaolo Bonzini     qemu_iovec_init_external(&qiov, &iov, 1);
94893f7ebaSPaolo Bonzini 
95b812f671SPaolo Bonzini     trace_mirror_one_iteration(s, sector_num, nb_sectors);
96b812f671SPaolo Bonzini     ret = bdrv_co_readv(source, sector_num, nb_sectors, &qiov);
97893f7ebaSPaolo Bonzini     if (ret < 0) {
98b952b558SPaolo Bonzini         *p_action = mirror_error_action(s, true, -ret);
99b952b558SPaolo Bonzini         goto fail;
100893f7ebaSPaolo Bonzini     }
101b812f671SPaolo Bonzini     ret = bdrv_co_writev(target, sector_num, nb_sectors, &qiov);
102b952b558SPaolo Bonzini     if (ret < 0) {
103b952b558SPaolo Bonzini         *p_action = mirror_error_action(s, false, -ret);
104b952b558SPaolo Bonzini         s->synced = false;
105b952b558SPaolo Bonzini         goto fail;
106b952b558SPaolo Bonzini     }
107b812f671SPaolo Bonzini     if (s->cow_bitmap) {
108*eee13dfeSPaolo Bonzini         bitmap_set(s->cow_bitmap, sector_num / sectors_per_chunk,
109*eee13dfeSPaolo Bonzini                    nb_sectors / sectors_per_chunk);
110b812f671SPaolo Bonzini     }
111b952b558SPaolo Bonzini     return 0;
112b952b558SPaolo Bonzini 
113b952b558SPaolo Bonzini fail:
114b952b558SPaolo Bonzini     /* Try again later.  */
115b812f671SPaolo Bonzini     bdrv_set_dirty(source, sector_num, nb_sectors);
116b952b558SPaolo Bonzini     return ret;
117893f7ebaSPaolo Bonzini }
118893f7ebaSPaolo Bonzini 
119893f7ebaSPaolo Bonzini static void coroutine_fn mirror_run(void *opaque)
120893f7ebaSPaolo Bonzini {
121893f7ebaSPaolo Bonzini     MirrorBlockJob *s = opaque;
122893f7ebaSPaolo Bonzini     BlockDriverState *bs = s->common.bs;
123*eee13dfeSPaolo Bonzini     int64_t sector_num, end, sectors_per_chunk, length;
124b812f671SPaolo Bonzini     BlockDriverInfo bdi;
125b812f671SPaolo Bonzini     char backing_filename[1024];
126893f7ebaSPaolo Bonzini     int ret = 0;
127893f7ebaSPaolo Bonzini     int n;
128893f7ebaSPaolo Bonzini 
129893f7ebaSPaolo Bonzini     if (block_job_is_cancelled(&s->common)) {
130893f7ebaSPaolo Bonzini         goto immediate_exit;
131893f7ebaSPaolo Bonzini     }
132893f7ebaSPaolo Bonzini 
133893f7ebaSPaolo Bonzini     s->common.len = bdrv_getlength(bs);
134893f7ebaSPaolo Bonzini     if (s->common.len < 0) {
135893f7ebaSPaolo Bonzini         block_job_completed(&s->common, s->common.len);
136893f7ebaSPaolo Bonzini         return;
137893f7ebaSPaolo Bonzini     }
138893f7ebaSPaolo Bonzini 
139b812f671SPaolo Bonzini     /* If we have no backing file yet in the destination, we cannot let
140b812f671SPaolo Bonzini      * the destination do COW.  Instead, we copy sectors around the
141b812f671SPaolo Bonzini      * dirty data if needed.  We need a bitmap to do that.
142b812f671SPaolo Bonzini      */
143b812f671SPaolo Bonzini     bdrv_get_backing_filename(s->target, backing_filename,
144b812f671SPaolo Bonzini                               sizeof(backing_filename));
145b812f671SPaolo Bonzini     if (backing_filename[0] && !s->target->backing_hd) {
146b812f671SPaolo Bonzini         bdrv_get_info(s->target, &bdi);
147*eee13dfeSPaolo Bonzini         if (s->granularity < bdi.cluster_size) {
148b812f671SPaolo Bonzini             s->buf_size = bdi.cluster_size;
149*eee13dfeSPaolo Bonzini             length = (bdrv_getlength(bs) + s->granularity - 1) / s->granularity;
150b812f671SPaolo Bonzini             s->cow_bitmap = bitmap_new(length);
151b812f671SPaolo Bonzini         }
152b812f671SPaolo Bonzini     }
153b812f671SPaolo Bonzini 
154893f7ebaSPaolo Bonzini     end = s->common.len >> BDRV_SECTOR_BITS;
155b812f671SPaolo Bonzini     s->buf = qemu_blockalign(bs, s->buf_size);
156*eee13dfeSPaolo Bonzini     sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS;
157893f7ebaSPaolo Bonzini 
158893f7ebaSPaolo Bonzini     if (s->mode != MIRROR_SYNC_MODE_NONE) {
159893f7ebaSPaolo Bonzini         /* First part, loop on the sectors and initialize the dirty bitmap.  */
160893f7ebaSPaolo Bonzini         BlockDriverState *base;
161893f7ebaSPaolo Bonzini         base = s->mode == MIRROR_SYNC_MODE_FULL ? NULL : bs->backing_hd;
162893f7ebaSPaolo Bonzini         for (sector_num = 0; sector_num < end; ) {
163*eee13dfeSPaolo Bonzini             int64_t next = (sector_num | (sectors_per_chunk - 1)) + 1;
164893f7ebaSPaolo Bonzini             ret = bdrv_co_is_allocated_above(bs, base,
165893f7ebaSPaolo Bonzini                                              sector_num, next - sector_num, &n);
166893f7ebaSPaolo Bonzini 
167893f7ebaSPaolo Bonzini             if (ret < 0) {
168893f7ebaSPaolo Bonzini                 goto immediate_exit;
169893f7ebaSPaolo Bonzini             }
170893f7ebaSPaolo Bonzini 
171893f7ebaSPaolo Bonzini             assert(n > 0);
172893f7ebaSPaolo Bonzini             if (ret == 1) {
173893f7ebaSPaolo Bonzini                 bdrv_set_dirty(bs, sector_num, n);
174893f7ebaSPaolo Bonzini                 sector_num = next;
175893f7ebaSPaolo Bonzini             } else {
176893f7ebaSPaolo Bonzini                 sector_num += n;
177893f7ebaSPaolo Bonzini             }
178893f7ebaSPaolo Bonzini         }
179893f7ebaSPaolo Bonzini     }
180893f7ebaSPaolo Bonzini 
1818f0720ecSPaolo Bonzini     bdrv_dirty_iter_init(bs, &s->hbi);
182893f7ebaSPaolo Bonzini     for (;;) {
183893f7ebaSPaolo Bonzini         uint64_t delay_ns;
184893f7ebaSPaolo Bonzini         int64_t cnt;
185893f7ebaSPaolo Bonzini         bool should_complete;
186893f7ebaSPaolo Bonzini 
187893f7ebaSPaolo Bonzini         cnt = bdrv_get_dirty_count(bs);
188893f7ebaSPaolo Bonzini         if (cnt != 0) {
189b952b558SPaolo Bonzini             BlockErrorAction action = BDRV_ACTION_REPORT;
190b952b558SPaolo Bonzini             ret = mirror_iteration(s, &action);
191b952b558SPaolo Bonzini             if (ret < 0 && action == BDRV_ACTION_REPORT) {
192893f7ebaSPaolo Bonzini                 goto immediate_exit;
193893f7ebaSPaolo Bonzini             }
194893f7ebaSPaolo Bonzini             cnt = bdrv_get_dirty_count(bs);
195893f7ebaSPaolo Bonzini         }
196893f7ebaSPaolo Bonzini 
197893f7ebaSPaolo Bonzini         should_complete = false;
198893f7ebaSPaolo Bonzini         if (cnt == 0) {
199893f7ebaSPaolo Bonzini             trace_mirror_before_flush(s);
200893f7ebaSPaolo Bonzini             ret = bdrv_flush(s->target);
201893f7ebaSPaolo Bonzini             if (ret < 0) {
202b952b558SPaolo Bonzini                 if (mirror_error_action(s, false, -ret) == BDRV_ACTION_REPORT) {
203893f7ebaSPaolo Bonzini                     goto immediate_exit;
204893f7ebaSPaolo Bonzini                 }
205b952b558SPaolo Bonzini             } else {
206893f7ebaSPaolo Bonzini                 /* We're out of the streaming phase.  From now on, if the job
207893f7ebaSPaolo Bonzini                  * is cancelled we will actually complete all pending I/O and
208893f7ebaSPaolo Bonzini                  * report completion.  This way, block-job-cancel will leave
209893f7ebaSPaolo Bonzini                  * the target in a consistent state.
210893f7ebaSPaolo Bonzini                  */
211893f7ebaSPaolo Bonzini                 s->common.offset = end * BDRV_SECTOR_SIZE;
212d63ffd87SPaolo Bonzini                 if (!s->synced) {
213d63ffd87SPaolo Bonzini                     block_job_ready(&s->common);
214d63ffd87SPaolo Bonzini                     s->synced = true;
215d63ffd87SPaolo Bonzini                 }
216d63ffd87SPaolo Bonzini 
217d63ffd87SPaolo Bonzini                 should_complete = s->should_complete ||
218d63ffd87SPaolo Bonzini                     block_job_is_cancelled(&s->common);
219893f7ebaSPaolo Bonzini                 cnt = bdrv_get_dirty_count(bs);
220893f7ebaSPaolo Bonzini             }
221b952b558SPaolo Bonzini         }
222893f7ebaSPaolo Bonzini 
223893f7ebaSPaolo Bonzini         if (cnt == 0 && should_complete) {
224893f7ebaSPaolo Bonzini             /* The dirty bitmap is not updated while operations are pending.
225893f7ebaSPaolo Bonzini              * If we're about to exit, wait for pending operations before
226893f7ebaSPaolo Bonzini              * calling bdrv_get_dirty_count(bs), or we may exit while the
227893f7ebaSPaolo Bonzini              * source has dirty data to copy!
228893f7ebaSPaolo Bonzini              *
229893f7ebaSPaolo Bonzini              * Note that I/O can be submitted by the guest while
230893f7ebaSPaolo Bonzini              * mirror_populate runs.
231893f7ebaSPaolo Bonzini              */
232893f7ebaSPaolo Bonzini             trace_mirror_before_drain(s, cnt);
233893f7ebaSPaolo Bonzini             bdrv_drain_all();
234893f7ebaSPaolo Bonzini             cnt = bdrv_get_dirty_count(bs);
235893f7ebaSPaolo Bonzini         }
236893f7ebaSPaolo Bonzini 
237893f7ebaSPaolo Bonzini         ret = 0;
238d63ffd87SPaolo Bonzini         trace_mirror_before_sleep(s, cnt, s->synced);
239d63ffd87SPaolo Bonzini         if (!s->synced) {
240893f7ebaSPaolo Bonzini             /* Publish progress */
241acc906c6SPaolo Bonzini             s->common.offset = (end - cnt) * BDRV_SECTOR_SIZE;
242893f7ebaSPaolo Bonzini 
243893f7ebaSPaolo Bonzini             if (s->common.speed) {
244*eee13dfeSPaolo Bonzini                 delay_ns = ratelimit_calculate_delay(&s->limit, sectors_per_chunk);
245893f7ebaSPaolo Bonzini             } else {
246893f7ebaSPaolo Bonzini                 delay_ns = 0;
247893f7ebaSPaolo Bonzini             }
248893f7ebaSPaolo Bonzini 
249893f7ebaSPaolo Bonzini             /* Note that even when no rate limit is applied we need to yield
250c57b6656SKevin Wolf              * with no pending I/O here so that bdrv_drain_all() returns.
251893f7ebaSPaolo Bonzini              */
252893f7ebaSPaolo Bonzini             block_job_sleep_ns(&s->common, rt_clock, delay_ns);
253893f7ebaSPaolo Bonzini             if (block_job_is_cancelled(&s->common)) {
254893f7ebaSPaolo Bonzini                 break;
255893f7ebaSPaolo Bonzini             }
256893f7ebaSPaolo Bonzini         } else if (!should_complete) {
257893f7ebaSPaolo Bonzini             delay_ns = (cnt == 0 ? SLICE_TIME : 0);
258893f7ebaSPaolo Bonzini             block_job_sleep_ns(&s->common, rt_clock, delay_ns);
259893f7ebaSPaolo Bonzini         } else if (cnt == 0) {
260893f7ebaSPaolo Bonzini             /* The two disks are in sync.  Exit and report successful
261893f7ebaSPaolo Bonzini              * completion.
262893f7ebaSPaolo Bonzini              */
263893f7ebaSPaolo Bonzini             assert(QLIST_EMPTY(&bs->tracked_requests));
264893f7ebaSPaolo Bonzini             s->common.cancelled = false;
265893f7ebaSPaolo Bonzini             break;
266893f7ebaSPaolo Bonzini         }
267893f7ebaSPaolo Bonzini     }
268893f7ebaSPaolo Bonzini 
269893f7ebaSPaolo Bonzini immediate_exit:
2707191bf31SMarkus Armbruster     qemu_vfree(s->buf);
271b812f671SPaolo Bonzini     g_free(s->cow_bitmap);
27250717e94SPaolo Bonzini     bdrv_set_dirty_tracking(bs, 0);
273b952b558SPaolo Bonzini     bdrv_iostatus_disable(s->target);
274d63ffd87SPaolo Bonzini     if (s->should_complete && ret == 0) {
275d63ffd87SPaolo Bonzini         if (bdrv_get_flags(s->target) != bdrv_get_flags(s->common.bs)) {
276d63ffd87SPaolo Bonzini             bdrv_reopen(s->target, bdrv_get_flags(s->common.bs), NULL);
277d63ffd87SPaolo Bonzini         }
278d63ffd87SPaolo Bonzini         bdrv_swap(s->target, s->common.bs);
279d63ffd87SPaolo Bonzini     }
280893f7ebaSPaolo Bonzini     bdrv_close(s->target);
281893f7ebaSPaolo Bonzini     bdrv_delete(s->target);
282893f7ebaSPaolo Bonzini     block_job_completed(&s->common, ret);
283893f7ebaSPaolo Bonzini }
284893f7ebaSPaolo Bonzini 
285893f7ebaSPaolo Bonzini static void mirror_set_speed(BlockJob *job, int64_t speed, Error **errp)
286893f7ebaSPaolo Bonzini {
287893f7ebaSPaolo Bonzini     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
288893f7ebaSPaolo Bonzini 
289893f7ebaSPaolo Bonzini     if (speed < 0) {
290893f7ebaSPaolo Bonzini         error_set(errp, QERR_INVALID_PARAMETER, "speed");
291893f7ebaSPaolo Bonzini         return;
292893f7ebaSPaolo Bonzini     }
293893f7ebaSPaolo Bonzini     ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME);
294893f7ebaSPaolo Bonzini }
295893f7ebaSPaolo Bonzini 
296b952b558SPaolo Bonzini static void mirror_iostatus_reset(BlockJob *job)
297b952b558SPaolo Bonzini {
298b952b558SPaolo Bonzini     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
299b952b558SPaolo Bonzini 
300b952b558SPaolo Bonzini     bdrv_iostatus_reset(s->target);
301b952b558SPaolo Bonzini }
302b952b558SPaolo Bonzini 
303d63ffd87SPaolo Bonzini static void mirror_complete(BlockJob *job, Error **errp)
304d63ffd87SPaolo Bonzini {
305d63ffd87SPaolo Bonzini     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
306d63ffd87SPaolo Bonzini     int ret;
307d63ffd87SPaolo Bonzini 
308d63ffd87SPaolo Bonzini     ret = bdrv_open_backing_file(s->target);
309d63ffd87SPaolo Bonzini     if (ret < 0) {
310d63ffd87SPaolo Bonzini         char backing_filename[PATH_MAX];
311d63ffd87SPaolo Bonzini         bdrv_get_full_backing_filename(s->target, backing_filename,
312d63ffd87SPaolo Bonzini                                        sizeof(backing_filename));
313d63ffd87SPaolo Bonzini         error_set(errp, QERR_OPEN_FILE_FAILED, backing_filename);
314d63ffd87SPaolo Bonzini         return;
315d63ffd87SPaolo Bonzini     }
316d63ffd87SPaolo Bonzini     if (!s->synced) {
317d63ffd87SPaolo Bonzini         error_set(errp, QERR_BLOCK_JOB_NOT_READY, job->bs->device_name);
318d63ffd87SPaolo Bonzini         return;
319d63ffd87SPaolo Bonzini     }
320d63ffd87SPaolo Bonzini 
321d63ffd87SPaolo Bonzini     s->should_complete = true;
322d63ffd87SPaolo Bonzini     block_job_resume(job);
323d63ffd87SPaolo Bonzini }
324d63ffd87SPaolo Bonzini 
325893f7ebaSPaolo Bonzini static BlockJobType mirror_job_type = {
326893f7ebaSPaolo Bonzini     .instance_size = sizeof(MirrorBlockJob),
327893f7ebaSPaolo Bonzini     .job_type      = "mirror",
328893f7ebaSPaolo Bonzini     .set_speed     = mirror_set_speed,
329b952b558SPaolo Bonzini     .iostatus_reset= mirror_iostatus_reset,
330d63ffd87SPaolo Bonzini     .complete      = mirror_complete,
331893f7ebaSPaolo Bonzini };
332893f7ebaSPaolo Bonzini 
333893f7ebaSPaolo Bonzini void mirror_start(BlockDriverState *bs, BlockDriverState *target,
334*eee13dfeSPaolo Bonzini                   int64_t speed, int64_t granularity, MirrorSyncMode mode,
335b952b558SPaolo Bonzini                   BlockdevOnError on_source_error,
336b952b558SPaolo Bonzini                   BlockdevOnError on_target_error,
337893f7ebaSPaolo Bonzini                   BlockDriverCompletionFunc *cb,
338893f7ebaSPaolo Bonzini                   void *opaque, Error **errp)
339893f7ebaSPaolo Bonzini {
340893f7ebaSPaolo Bonzini     MirrorBlockJob *s;
341893f7ebaSPaolo Bonzini 
342*eee13dfeSPaolo Bonzini     if (granularity == 0) {
343*eee13dfeSPaolo Bonzini         /* Choose the default granularity based on the target file's cluster
344*eee13dfeSPaolo Bonzini          * size, clamped between 4k and 64k.  */
345*eee13dfeSPaolo Bonzini         BlockDriverInfo bdi;
346*eee13dfeSPaolo Bonzini         if (bdrv_get_info(target, &bdi) >= 0 && bdi.cluster_size != 0) {
347*eee13dfeSPaolo Bonzini             granularity = MAX(4096, bdi.cluster_size);
348*eee13dfeSPaolo Bonzini             granularity = MIN(65536, granularity);
349*eee13dfeSPaolo Bonzini         } else {
350*eee13dfeSPaolo Bonzini             granularity = 65536;
351*eee13dfeSPaolo Bonzini         }
352*eee13dfeSPaolo Bonzini     }
353*eee13dfeSPaolo Bonzini 
354*eee13dfeSPaolo Bonzini     assert ((granularity & (granularity - 1)) == 0);
355*eee13dfeSPaolo Bonzini 
356b952b558SPaolo Bonzini     if ((on_source_error == BLOCKDEV_ON_ERROR_STOP ||
357b952b558SPaolo Bonzini          on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
358b952b558SPaolo Bonzini         !bdrv_iostatus_is_enabled(bs)) {
359b952b558SPaolo Bonzini         error_set(errp, QERR_INVALID_PARAMETER, "on-source-error");
360b952b558SPaolo Bonzini         return;
361b952b558SPaolo Bonzini     }
362b952b558SPaolo Bonzini 
363893f7ebaSPaolo Bonzini     s = block_job_create(&mirror_job_type, bs, speed, cb, opaque, errp);
364893f7ebaSPaolo Bonzini     if (!s) {
365893f7ebaSPaolo Bonzini         return;
366893f7ebaSPaolo Bonzini     }
367893f7ebaSPaolo Bonzini 
368b952b558SPaolo Bonzini     s->on_source_error = on_source_error;
369b952b558SPaolo Bonzini     s->on_target_error = on_target_error;
370893f7ebaSPaolo Bonzini     s->target = target;
371893f7ebaSPaolo Bonzini     s->mode = mode;
372*eee13dfeSPaolo Bonzini     s->granularity = granularity;
373*eee13dfeSPaolo Bonzini     s->buf_size = granularity;
374b812f671SPaolo Bonzini 
375*eee13dfeSPaolo Bonzini     bdrv_set_dirty_tracking(bs, granularity);
376893f7ebaSPaolo Bonzini     bdrv_set_enable_write_cache(s->target, true);
377b952b558SPaolo Bonzini     bdrv_set_on_error(s->target, on_target_error, on_target_error);
378b952b558SPaolo Bonzini     bdrv_iostatus_enable(s->target);
379893f7ebaSPaolo Bonzini     s->common.co = qemu_coroutine_create(mirror_run);
380893f7ebaSPaolo Bonzini     trace_mirror_start(bs, s, s->common.co, opaque);
381893f7ebaSPaolo Bonzini     qemu_coroutine_enter(s->common.co, s);
382893f7ebaSPaolo Bonzini }
383