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d8e7d87e MP |
1 | /* |
2 | * QEMU block throttling filter driver infrastructure | |
3 | * | |
4 | * Copyright (c) 2017 Manos Pitsidianakis | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License as | |
8 | * published by the Free Software Foundation; either version 2 or | |
9 | * (at your option) version 3 of the License. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | ||
20 | #include "qemu/osdep.h" | |
e2c1c34f MA |
21 | #include "block/block-io.h" |
22 | #include "block/block_int.h" | |
d8e7d87e | 23 | #include "block/throttle-groups.h" |
0b8fa32f | 24 | #include "qemu/module.h" |
922a01a0 | 25 | #include "qemu/option.h" |
d8e7d87e MP |
26 | #include "qemu/throttle-options.h" |
27 | #include "qapi/error.h" | |
28 | ||
29 | static QemuOptsList throttle_opts = { | |
30 | .name = "throttle", | |
31 | .head = QTAILQ_HEAD_INITIALIZER(throttle_opts.head), | |
32 | .desc = { | |
33 | { | |
34 | .name = QEMU_OPT_THROTTLE_GROUP_NAME, | |
35 | .type = QEMU_OPT_STRING, | |
36 | .help = "Name of the throttle group", | |
37 | }, | |
38 | { /* end of list */ } | |
39 | }, | |
40 | }; | |
41 | ||
bc33c047 AG |
42 | /* |
43 | * If this function succeeds then the throttle group name is stored in | |
44 | * @group and must be freed by the caller. | |
45 | * If there's an error then @group remains unmodified. | |
46 | */ | |
47 | static int throttle_parse_options(QDict *options, char **group, Error **errp) | |
d8e7d87e MP |
48 | { |
49 | int ret; | |
50 | const char *group_name; | |
d8e7d87e MP |
51 | QemuOpts *opts = qemu_opts_create(&throttle_opts, NULL, 0, &error_abort); |
52 | ||
af175e85 | 53 | if (!qemu_opts_absorb_qdict(opts, options, errp)) { |
d8e7d87e MP |
54 | ret = -EINVAL; |
55 | goto fin; | |
56 | } | |
57 | ||
58 | group_name = qemu_opt_get(opts, QEMU_OPT_THROTTLE_GROUP_NAME); | |
59 | if (!group_name) { | |
60 | error_setg(errp, "Please specify a throttle group"); | |
61 | ret = -EINVAL; | |
62 | goto fin; | |
63 | } else if (!throttle_group_exists(group_name)) { | |
64 | error_setg(errp, "Throttle group '%s' does not exist", group_name); | |
65 | ret = -EINVAL; | |
66 | goto fin; | |
67 | } | |
68 | ||
bc33c047 | 69 | *group = g_strdup(group_name); |
d8e7d87e MP |
70 | ret = 0; |
71 | fin: | |
72 | qemu_opts_del(opts); | |
73 | return ret; | |
74 | } | |
75 | ||
76 | static int throttle_open(BlockDriverState *bs, QDict *options, | |
77 | int flags, Error **errp) | |
78 | { | |
79 | ThrottleGroupMember *tgm = bs->opaque; | |
bc33c047 AG |
80 | char *group; |
81 | int ret; | |
d8e7d87e | 82 | |
83930780 VSO |
83 | ret = bdrv_open_file_child(NULL, options, "file", bs, errp); |
84 | if (ret < 0) { | |
85 | return ret; | |
d8e7d87e | 86 | } |
a4b740db KW |
87 | |
88 | GRAPH_RDLOCK_GUARD_MAINLOOP(); | |
89 | ||
228345bf HR |
90 | bs->supported_write_flags = bs->file->bs->supported_write_flags | |
91 | BDRV_REQ_WRITE_UNCHANGED; | |
92 | bs->supported_zero_flags = bs->file->bs->supported_zero_flags | | |
93 | BDRV_REQ_WRITE_UNCHANGED; | |
d8e7d87e | 94 | |
bc33c047 AG |
95 | ret = throttle_parse_options(options, &group, errp); |
96 | if (ret == 0) { | |
97 | /* Register membership to group with name group_name */ | |
98 | throttle_group_register_tgm(tgm, group, bdrv_get_aio_context(bs)); | |
99 | g_free(group); | |
100 | } | |
101 | ||
102 | return ret; | |
d8e7d87e MP |
103 | } |
104 | ||
105 | static void throttle_close(BlockDriverState *bs) | |
106 | { | |
107 | ThrottleGroupMember *tgm = bs->opaque; | |
108 | throttle_group_unregister_tgm(tgm); | |
109 | } | |
110 | ||
111 | ||
8ab8140a KW |
112 | static int64_t coroutine_fn GRAPH_RDLOCK |
113 | throttle_co_getlength(BlockDriverState *bs) | |
d8e7d87e | 114 | { |
c86422c5 | 115 | return bdrv_co_getlength(bs->file->bs); |
d8e7d87e MP |
116 | } |
117 | ||
b9b10c35 KW |
118 | static int coroutine_fn GRAPH_RDLOCK |
119 | throttle_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, | |
120 | QEMUIOVector *qiov, BdrvRequestFlags flags) | |
d8e7d87e MP |
121 | { |
122 | ||
123 | ThrottleGroupMember *tgm = bs->opaque; | |
3b2337ef | 124 | throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_READ); |
d8e7d87e MP |
125 | |
126 | return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); | |
127 | } | |
128 | ||
b9b10c35 KW |
129 | static int coroutine_fn GRAPH_RDLOCK |
130 | throttle_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, | |
131 | QEMUIOVector *qiov, BdrvRequestFlags flags) | |
d8e7d87e MP |
132 | { |
133 | ThrottleGroupMember *tgm = bs->opaque; | |
3b2337ef | 134 | throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_WRITE); |
d8e7d87e MP |
135 | |
136 | return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags); | |
137 | } | |
138 | ||
abaf8b75 KW |
139 | static int coroutine_fn GRAPH_RDLOCK |
140 | throttle_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, | |
141 | BdrvRequestFlags flags) | |
d8e7d87e MP |
142 | { |
143 | ThrottleGroupMember *tgm = bs->opaque; | |
3b2337ef | 144 | throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_WRITE); |
d8e7d87e MP |
145 | |
146 | return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags); | |
147 | } | |
148 | ||
9a5a1c62 EGE |
149 | static int coroutine_fn GRAPH_RDLOCK |
150 | throttle_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) | |
d8e7d87e MP |
151 | { |
152 | ThrottleGroupMember *tgm = bs->opaque; | |
3b2337ef | 153 | throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_WRITE); |
d8e7d87e | 154 | |
0b9fd3f4 | 155 | return bdrv_co_pdiscard(bs->file, offset, bytes); |
d8e7d87e MP |
156 | } |
157 | ||
b9b10c35 KW |
158 | static int coroutine_fn GRAPH_RDLOCK |
159 | throttle_co_pwritev_compressed(BlockDriverState *bs, int64_t offset, | |
160 | int64_t bytes, QEMUIOVector *qiov) | |
e7e754ae HR |
161 | { |
162 | return throttle_co_pwritev(bs, offset, bytes, qiov, | |
163 | BDRV_REQ_WRITE_COMPRESSED); | |
164 | } | |
165 | ||
88095349 | 166 | static int coroutine_fn GRAPH_RDLOCK throttle_co_flush(BlockDriverState *bs) |
d8e7d87e MP |
167 | { |
168 | return bdrv_co_flush(bs->file->bs); | |
169 | } | |
170 | ||
171 | static void throttle_detach_aio_context(BlockDriverState *bs) | |
172 | { | |
173 | ThrottleGroupMember *tgm = bs->opaque; | |
174 | throttle_group_detach_aio_context(tgm); | |
175 | } | |
176 | ||
177 | static void throttle_attach_aio_context(BlockDriverState *bs, | |
178 | AioContext *new_context) | |
179 | { | |
180 | ThrottleGroupMember *tgm = bs->opaque; | |
181 | throttle_group_attach_aio_context(tgm, new_context); | |
182 | } | |
183 | ||
184 | static int throttle_reopen_prepare(BDRVReopenState *reopen_state, | |
185 | BlockReopenQueue *queue, Error **errp) | |
186 | { | |
bc33c047 AG |
187 | int ret; |
188 | char *group = NULL; | |
d8e7d87e MP |
189 | |
190 | assert(reopen_state != NULL); | |
191 | assert(reopen_state->bs != NULL); | |
192 | ||
bc33c047 AG |
193 | ret = throttle_parse_options(reopen_state->options, &group, errp); |
194 | reopen_state->opaque = group; | |
195 | return ret; | |
d8e7d87e MP |
196 | } |
197 | ||
198 | static void throttle_reopen_commit(BDRVReopenState *reopen_state) | |
199 | { | |
bc33c047 AG |
200 | BlockDriverState *bs = reopen_state->bs; |
201 | ThrottleGroupMember *tgm = bs->opaque; | |
202 | char *group = reopen_state->opaque; | |
203 | ||
204 | assert(group); | |
d8e7d87e | 205 | |
bc33c047 AG |
206 | if (strcmp(group, throttle_group_get_name(tgm))) { |
207 | throttle_group_unregister_tgm(tgm); | |
208 | throttle_group_register_tgm(tgm, group, bdrv_get_aio_context(bs)); | |
209 | } | |
210 | g_free(reopen_state->opaque); | |
d8e7d87e MP |
211 | reopen_state->opaque = NULL; |
212 | } | |
213 | ||
214 | static void throttle_reopen_abort(BDRVReopenState *reopen_state) | |
215 | { | |
bc33c047 | 216 | g_free(reopen_state->opaque); |
d8e7d87e MP |
217 | reopen_state->opaque = NULL; |
218 | } | |
219 | ||
5e8ac217 | 220 | static void throttle_drain_begin(BlockDriverState *bs) |
b867eaa1 MP |
221 | { |
222 | ThrottleGroupMember *tgm = bs->opaque; | |
d73415a3 | 223 | if (qatomic_fetch_inc(&tgm->io_limits_disabled) == 0) { |
b867eaa1 MP |
224 | throttle_group_restart_tgm(tgm); |
225 | } | |
226 | } | |
227 | ||
5e8ac217 | 228 | static void throttle_drain_end(BlockDriverState *bs) |
b867eaa1 MP |
229 | { |
230 | ThrottleGroupMember *tgm = bs->opaque; | |
231 | assert(tgm->io_limits_disabled); | |
d73415a3 | 232 | qatomic_dec(&tgm->io_limits_disabled); |
b867eaa1 MP |
233 | } |
234 | ||
2654267c HR |
235 | static const char *const throttle_strong_runtime_opts[] = { |
236 | QEMU_OPT_THROTTLE_GROUP_NAME, | |
237 | ||
238 | NULL | |
239 | }; | |
240 | ||
d8e7d87e MP |
241 | static BlockDriver bdrv_throttle = { |
242 | .format_name = "throttle", | |
d8e7d87e MP |
243 | .instance_size = sizeof(ThrottleGroupMember), |
244 | ||
a7328ba5 | 245 | .bdrv_open = throttle_open, |
d8e7d87e MP |
246 | .bdrv_close = throttle_close, |
247 | .bdrv_co_flush = throttle_co_flush, | |
248 | ||
69dca43d | 249 | .bdrv_child_perm = bdrv_default_perms, |
d8e7d87e | 250 | |
c86422c5 | 251 | .bdrv_co_getlength = throttle_co_getlength, |
d8e7d87e MP |
252 | |
253 | .bdrv_co_preadv = throttle_co_preadv, | |
254 | .bdrv_co_pwritev = throttle_co_pwritev, | |
255 | ||
256 | .bdrv_co_pwrite_zeroes = throttle_co_pwrite_zeroes, | |
257 | .bdrv_co_pdiscard = throttle_co_pdiscard, | |
e7e754ae | 258 | .bdrv_co_pwritev_compressed = throttle_co_pwritev_compressed, |
d8e7d87e | 259 | |
d8e7d87e MP |
260 | .bdrv_attach_aio_context = throttle_attach_aio_context, |
261 | .bdrv_detach_aio_context = throttle_detach_aio_context, | |
262 | ||
263 | .bdrv_reopen_prepare = throttle_reopen_prepare, | |
264 | .bdrv_reopen_commit = throttle_reopen_commit, | |
265 | .bdrv_reopen_abort = throttle_reopen_abort, | |
d8e7d87e | 266 | |
5e8ac217 KW |
267 | .bdrv_drain_begin = throttle_drain_begin, |
268 | .bdrv_drain_end = throttle_drain_end, | |
b867eaa1 | 269 | |
d8e7d87e | 270 | .is_filter = true, |
2654267c | 271 | .strong_runtime_opts = throttle_strong_runtime_opts, |
d8e7d87e MP |
272 | }; |
273 | ||
274 | static void bdrv_throttle_init(void) | |
275 | { | |
276 | bdrv_register(&bdrv_throttle); | |
277 | } | |
278 | ||
279 | block_init(bdrv_throttle_init); |