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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
57static int stream_prepare(Job *job)
58{
59 StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
60 BlockJob *bjob = &s->common;
61 BlockDriverState *bs = blk_bs(bjob->blk);
62 BlockDriverState *base = s->base;
63 Error *local_err = NULL;
64 int ret = 0;
65
66 if (bs->backing) {
67 const char *base_id = NULL, *base_fmt = NULL;
68 if (base) {
69 base_id = s->backing_file_str;
70 if (base->drv) {
71 base_fmt = base->drv->format_name;
72 }
73 }
74 ret = bdrv_change_backing_file(bs, base_id, base_fmt);
75 bdrv_set_backing_hd(bs, base, &local_err);
76 if (local_err) {
77 error_report_err(local_err);
78 return -EPERM;
79 }
80 }
81
82 return ret;
83}
84
85static void stream_clean(Job *job)
86{
87 StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
88 BlockJob *bjob = &s->common;
89 BlockDriverState *bs = blk_bs(bjob->blk);
90
91
92 if (s->bs_flags != bdrv_get_flags(bs)) {
93
94 blk_set_perm(bjob->blk, 0, BLK_PERM_ALL, &error_abort);
95 bdrv_reopen(bs, s->bs_flags, NULL);
96 }
97
98 g_free(s->backing_file_str);
99}
100
101static int coroutine_fn stream_run(Job *job, Error **errp)
102{
103 StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
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 return ret;
207}
208
209static const BlockJobDriver stream_job_driver = {
210 .job_driver = {
211 .instance_size = sizeof(StreamBlockJob),
212 .job_type = JOB_TYPE_STREAM,
213 .free = block_job_free,
214 .run = stream_run,
215 .prepare = stream_prepare,
216 .clean = stream_clean,
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 int creation_flags, int64_t speed,
225 BlockdevOnError on_error, Error **errp)
226{
227 StreamBlockJob *s;
228 BlockDriverState *iter;
229 int orig_bs_flags;
230
231
232 orig_bs_flags = bdrv_get_flags(bs);
233 if (!(orig_bs_flags & BDRV_O_RDWR)) {
234 if (bdrv_reopen(bs, orig_bs_flags | BDRV_O_RDWR, errp) != 0) {
235 return;
236 }
237 }
238
239
240
241
242 s = block_job_create(job_id, &stream_job_driver, NULL, bs,
243 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
244 BLK_PERM_GRAPH_MOD,
245 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
246 BLK_PERM_WRITE,
247 speed, creation_flags, NULL, NULL, errp);
248 if (!s) {
249 goto fail;
250 }
251
252
253
254
255
256 for (iter = backing_bs(bs); iter && iter != base; iter = backing_bs(iter)) {
257 block_job_add_bdrv(&s->common, "intermediate node", iter, 0,
258 BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED,
259 &error_abort);
260 }
261
262 s->base = base;
263 s->backing_file_str = g_strdup(backing_file_str);
264 s->bs_flags = orig_bs_flags;
265
266 s->on_error = on_error;
267 trace_stream_start(bs, base, s);
268 job_start(&s->common.job);
269 return;
270
271fail:
272 if (orig_bs_flags != bdrv_get_flags(bs)) {
273 bdrv_reopen(bs, orig_bs_flags, NULL);
274 }
275}
276