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14#include "qemu/osdep.h"
15#include "trace.h"
16#include "block/block_int.h"
17#include "block/blockjob_int.h"
18#include "qapi/error.h"
19#include "qapi/qmp/qerror.h"
20#include "qemu/ratelimit.h"
21#include "sysemu/block-backend.h"
22
23enum {
24
25
26
27
28
29 STREAM_BUFFER_SIZE = 512 * 1024,
30};
31
32typedef struct StreamBlockJob {
33 BlockJob common;
34 BlockDriverState *base;
35 BlockdevOnError on_error;
36 char *backing_file_str;
37 int bs_flags;
38} StreamBlockJob;
39
40static int coroutine_fn stream_populate(BlockBackend *blk,
41 int64_t offset, uint64_t bytes,
42 void *buf)
43{
44 struct iovec iov = {
45 .iov_base = buf,
46 .iov_len = bytes,
47 };
48 QEMUIOVector qiov;
49
50 assert(bytes < SIZE_MAX);
51 qemu_iovec_init_external(&qiov, &iov, 1);
52
53
54 return blk_co_preadv(blk, offset, qiov.size, &qiov, BDRV_REQ_COPY_ON_READ);
55}
56
57typedef struct {
58 int ret;
59} StreamCompleteData;
60
61static void stream_complete(Job *job, void *opaque)
62{
63 StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
64 BlockJob *bjob = &s->common;
65 StreamCompleteData *data = opaque;
66 BlockDriverState *bs = blk_bs(bjob->blk);
67 BlockDriverState *base = s->base;
68 Error *local_err = NULL;
69
70 if (!job_is_cancelled(job) && bs->backing && data->ret == 0) {
71 const char *base_id = NULL, *base_fmt = NULL;
72 if (base) {
73 base_id = s->backing_file_str;
74 if (base->drv) {
75 base_fmt = base->drv->format_name;
76 }
77 }
78 data->ret = bdrv_change_backing_file(bs, base_id, base_fmt);
79 bdrv_set_backing_hd(bs, base, &local_err);
80 if (local_err) {
81 error_report_err(local_err);
82 data->ret = -EPERM;
83 goto out;
84 }
85 }
86
87out:
88
89 if (s->bs_flags != bdrv_get_flags(bs)) {
90
91 blk_set_perm(bjob->blk, 0, BLK_PERM_ALL, &error_abort);
92 bdrv_reopen(bs, s->bs_flags, NULL);
93 }
94
95 g_free(s->backing_file_str);
96 job_completed(job, data->ret, NULL);
97 g_free(data);
98}
99
100static void coroutine_fn stream_run(void *opaque)
101{
102 StreamBlockJob *s = opaque;
103 StreamCompleteData *data;
104 BlockBackend *blk = s->common.blk;
105 BlockDriverState *bs = blk_bs(blk);
106 BlockDriverState *base = s->base;
107 int64_t len;
108 int64_t offset = 0;
109 uint64_t delay_ns = 0;
110 int error = 0;
111 int ret = 0;
112 int64_t n = 0;
113 void *buf;
114
115 if (!bs->backing) {
116 goto out;
117 }
118
119 len = bdrv_getlength(bs);
120 if (len < 0) {
121 ret = len;
122 goto out;
123 }
124 job_progress_set_remaining(&s->common.job, len);
125
126 buf = qemu_blockalign(bs, STREAM_BUFFER_SIZE);
127
128
129
130
131
132
133 if (!base) {
134 bdrv_enable_copy_on_read(bs);
135 }
136
137 for ( ; offset < len; offset += n) {
138 bool copy;
139
140
141
142
143 job_sleep_ns(&s->common.job, delay_ns);
144 if (job_is_cancelled(&s->common.job)) {
145 break;
146 }
147
148 copy = false;
149
150 ret = bdrv_is_allocated(bs, offset, STREAM_BUFFER_SIZE, &n);
151 if (ret == 1) {
152
153 } else if (ret >= 0) {
154
155
156 ret = bdrv_is_allocated_above(backing_bs(bs), base,
157 offset, n, &n);
158
159
160 if (ret == 0 && n == 0) {
161 n = len - offset;
162 }
163
164 copy = (ret == 1);
165 }
166 trace_stream_one_iteration(s, offset, n, ret);
167 if (copy) {
168 ret = stream_populate(blk, offset, n, buf);
169 }
170 if (ret < 0) {
171 BlockErrorAction action =
172 block_job_error_action(&s->common, s->on_error, true, -ret);
173 if (action == BLOCK_ERROR_ACTION_STOP) {
174 n = 0;
175 continue;
176 }
177 if (error == 0) {
178 error = ret;
179 }
180 if (action == BLOCK_ERROR_ACTION_REPORT) {
181 break;
182 }
183 }
184 ret = 0;
185
186
187 job_progress_update(&s->common.job, n);
188 if (copy) {
189 delay_ns = block_job_ratelimit_get_delay(&s->common, n);
190 } else {
191 delay_ns = 0;
192 }
193 }
194
195 if (!base) {
196 bdrv_disable_copy_on_read(bs);
197 }
198
199
200 ret = error;
201
202 qemu_vfree(buf);
203
204out:
205
206 data = g_malloc(sizeof(*data));
207 data->ret = ret;
208 job_defer_to_main_loop(&s->common.job, stream_complete, data);
209}
210
211static const BlockJobDriver stream_job_driver = {
212 .job_driver = {
213 .instance_size = sizeof(StreamBlockJob),
214 .job_type = JOB_TYPE_STREAM,
215 .free = block_job_free,
216 .start = stream_run,
217 .user_resume = block_job_user_resume,
218 .drain = block_job_drain,
219 },
220};
221
222void stream_start(const char *job_id, BlockDriverState *bs,
223 BlockDriverState *base, const char *backing_file_str,
224 int64_t speed, BlockdevOnError on_error, Error **errp)
225{
226 StreamBlockJob *s;
227 BlockDriverState *iter;
228 int orig_bs_flags;
229
230
231 orig_bs_flags = bdrv_get_flags(bs);
232 if (!(orig_bs_flags & BDRV_O_RDWR)) {
233 if (bdrv_reopen(bs, orig_bs_flags | BDRV_O_RDWR, errp) != 0) {
234 return;
235 }
236 }
237
238
239
240
241 s = block_job_create(job_id, &stream_job_driver, NULL, bs,
242 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
243 BLK_PERM_GRAPH_MOD,
244 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
245 BLK_PERM_WRITE,
246 speed, JOB_DEFAULT, NULL, NULL, errp);
247 if (!s) {
248 goto fail;
249 }
250
251
252
253
254
255 for (iter = backing_bs(bs); iter && iter != base; iter = backing_bs(iter)) {
256 block_job_add_bdrv(&s->common, "intermediate node", iter, 0,
257 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED,
258 &error_abort);
259 }
260
261 s->base = base;
262 s->backing_file_str = g_strdup(backing_file_str);
263 s->bs_flags = orig_bs_flags;
264
265 s->on_error = on_error;
266 trace_stream_start(bs, base, s);
267 job_start(&s->common.job);
268 return;
269
270fail:
271 if (orig_bs_flags != bdrv_get_flags(bs)) {
272 bdrv_reopen(bs, orig_bs_flags, NULL);
273 }
274}
275