vmxnet3: Use common MAC address tracing macros
[qemu.git] / block / stream.c
1 /*
2 * Image streaming
3 *
4 * Copyright IBM, Corp. 2011
5 *
6 * Authors:
7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
8 *
9 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
10 * See the COPYING.LIB file in the top-level directory.
11 *
12 */
13
14 #include "qemu/osdep.h"
15 #include "trace.h"
16 #include "block/block_int.h"
17 #include "block/blockjob.h"
18 #include "qapi/error.h"
19 #include "qapi/qmp/qerror.h"
20 #include "qemu/ratelimit.h"
21 #include "sysemu/block-backend.h"
22
23 enum {
24 /*
25 * Size of data buffer for populating the image file. This should be large
26 * enough to process multiple clusters in a single call, so that populating
27 * contiguous regions of the image is efficient.
28 */
29 STREAM_BUFFER_SIZE = 512 * 1024, /* in bytes */
30 };
31
32 #define SLICE_TIME 100000000ULL /* ns */
33
34 typedef struct StreamBlockJob {
35 BlockJob common;
36 RateLimit limit;
37 BlockDriverState *base;
38 BlockdevOnError on_error;
39 char *backing_file_str;
40 } StreamBlockJob;
41
42 static int coroutine_fn stream_populate(BlockDriverState *bs,
43 int64_t sector_num, int nb_sectors,
44 void *buf)
45 {
46 struct iovec iov = {
47 .iov_base = buf,
48 .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
49 };
50 QEMUIOVector qiov;
51
52 qemu_iovec_init_external(&qiov, &iov, 1);
53
54 /* Copy-on-read the unallocated clusters */
55 return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov);
56 }
57
58 typedef struct {
59 int ret;
60 bool reached_end;
61 } StreamCompleteData;
62
63 static void stream_complete(BlockJob *job, void *opaque)
64 {
65 StreamBlockJob *s = container_of(job, StreamBlockJob, common);
66 StreamCompleteData *data = opaque;
67 BlockDriverState *base = s->base;
68
69 if (!block_job_is_cancelled(&s->common) && data->reached_end &&
70 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(job->bs, base_id, base_fmt);
79 bdrv_set_backing_hd(job->bs, base);
80 }
81
82 g_free(s->backing_file_str);
83 block_job_completed(&s->common, data->ret);
84 g_free(data);
85 }
86
87 static void coroutine_fn stream_run(void *opaque)
88 {
89 StreamBlockJob *s = opaque;
90 StreamCompleteData *data;
91 BlockDriverState *bs = s->common.bs;
92 BlockDriverState *base = s->base;
93 int64_t sector_num = 0;
94 int64_t end = -1;
95 int error = 0;
96 int ret = 0;
97 int n = 0;
98 void *buf;
99
100 if (!bs->backing) {
101 goto out;
102 }
103
104 s->common.len = bdrv_getlength(bs);
105 if (s->common.len < 0) {
106 ret = s->common.len;
107 goto out;
108 }
109
110 end = s->common.len >> BDRV_SECTOR_BITS;
111 buf = qemu_blockalign(bs, STREAM_BUFFER_SIZE);
112
113 /* Turn on copy-on-read for the whole block device so that guest read
114 * requests help us make progress. Only do this when copying the entire
115 * backing chain since the copy-on-read operation does not take base into
116 * account.
117 */
118 if (!base) {
119 bdrv_enable_copy_on_read(bs);
120 }
121
122 for (sector_num = 0; sector_num < end; sector_num += n) {
123 uint64_t delay_ns = 0;
124 bool copy;
125
126 wait:
127 /* Note that even when no rate limit is applied we need to yield
128 * with no pending I/O here so that bdrv_drain_all() returns.
129 */
130 block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns);
131 if (block_job_is_cancelled(&s->common)) {
132 break;
133 }
134
135 copy = false;
136
137 ret = bdrv_is_allocated(bs, sector_num,
138 STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n);
139 if (ret == 1) {
140 /* Allocated in the top, no need to copy. */
141 } else if (ret >= 0) {
142 /* Copy if allocated in the intermediate images. Limit to the
143 * known-unallocated area [sector_num, sector_num+n). */
144 ret = bdrv_is_allocated_above(backing_bs(bs), base,
145 sector_num, n, &n);
146
147 /* Finish early if end of backing file has been reached */
148 if (ret == 0 && n == 0) {
149 n = end - sector_num;
150 }
151
152 copy = (ret == 1);
153 }
154 trace_stream_one_iteration(s, sector_num, n, ret);
155 if (copy) {
156 if (s->common.speed) {
157 delay_ns = ratelimit_calculate_delay(&s->limit, n);
158 if (delay_ns > 0) {
159 goto wait;
160 }
161 }
162 ret = stream_populate(bs, sector_num, n, buf);
163 }
164 if (ret < 0) {
165 BlockErrorAction action =
166 block_job_error_action(&s->common, s->on_error, true, -ret);
167 if (action == BLOCK_ERROR_ACTION_STOP) {
168 n = 0;
169 continue;
170 }
171 if (error == 0) {
172 error = ret;
173 }
174 if (action == BLOCK_ERROR_ACTION_REPORT) {
175 break;
176 }
177 }
178 ret = 0;
179
180 /* Publish progress */
181 s->common.offset += n * BDRV_SECTOR_SIZE;
182 }
183
184 if (!base) {
185 bdrv_disable_copy_on_read(bs);
186 }
187
188 /* Do not remove the backing file if an error was there but ignored. */
189 ret = error;
190
191 qemu_vfree(buf);
192
193 out:
194 /* Modify backing chain and close BDSes in main loop */
195 data = g_malloc(sizeof(*data));
196 data->ret = ret;
197 data->reached_end = sector_num == end;
198 block_job_defer_to_main_loop(&s->common, stream_complete, data);
199 }
200
201 static void stream_set_speed(BlockJob *job, int64_t speed, Error **errp)
202 {
203 StreamBlockJob *s = container_of(job, StreamBlockJob, common);
204
205 if (speed < 0) {
206 error_setg(errp, QERR_INVALID_PARAMETER, "speed");
207 return;
208 }
209 ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME);
210 }
211
212 static const BlockJobDriver stream_job_driver = {
213 .instance_size = sizeof(StreamBlockJob),
214 .job_type = BLOCK_JOB_TYPE_STREAM,
215 .set_speed = stream_set_speed,
216 };
217
218 void stream_start(BlockDriverState *bs, BlockDriverState *base,
219 const char *backing_file_str, int64_t speed,
220 BlockdevOnError on_error,
221 BlockCompletionFunc *cb,
222 void *opaque, Error **errp)
223 {
224 StreamBlockJob *s;
225
226 s = block_job_create(&stream_job_driver, bs, speed, cb, opaque, errp);
227 if (!s) {
228 return;
229 }
230
231 s->base = base;
232 s->backing_file_str = g_strdup(backing_file_str);
233
234 s->on_error = on_error;
235 s->common.co = qemu_coroutine_create(stream_run);
236 trace_stream_start(bs, base, s, s->common.co, opaque);
237 qemu_coroutine_enter(s->common.co, s);
238 }