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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 | } |
228345bf HR |
87 | bs->supported_write_flags = bs->file->bs->supported_write_flags | |
88 | BDRV_REQ_WRITE_UNCHANGED; | |
89 | bs->supported_zero_flags = bs->file->bs->supported_zero_flags | | |
90 | BDRV_REQ_WRITE_UNCHANGED; | |
d8e7d87e | 91 | |
bc33c047 AG |
92 | ret = throttle_parse_options(options, &group, errp); |
93 | if (ret == 0) { | |
94 | /* Register membership to group with name group_name */ | |
95 | throttle_group_register_tgm(tgm, group, bdrv_get_aio_context(bs)); | |
96 | g_free(group); | |
97 | } | |
98 | ||
99 | return ret; | |
d8e7d87e MP |
100 | } |
101 | ||
102 | static void throttle_close(BlockDriverState *bs) | |
103 | { | |
104 | ThrottleGroupMember *tgm = bs->opaque; | |
105 | throttle_group_unregister_tgm(tgm); | |
106 | } | |
107 | ||
108 | ||
c86422c5 | 109 | static int64_t coroutine_fn throttle_co_getlength(BlockDriverState *bs) |
d8e7d87e | 110 | { |
c86422c5 | 111 | return bdrv_co_getlength(bs->file->bs); |
d8e7d87e MP |
112 | } |
113 | ||
b9b10c35 KW |
114 | static int coroutine_fn GRAPH_RDLOCK |
115 | throttle_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, | |
116 | QEMUIOVector *qiov, BdrvRequestFlags flags) | |
d8e7d87e MP |
117 | { |
118 | ||
119 | ThrottleGroupMember *tgm = bs->opaque; | |
120 | throttle_group_co_io_limits_intercept(tgm, bytes, false); | |
121 | ||
122 | return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); | |
123 | } | |
124 | ||
b9b10c35 KW |
125 | static int coroutine_fn GRAPH_RDLOCK |
126 | throttle_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, | |
127 | QEMUIOVector *qiov, BdrvRequestFlags flags) | |
d8e7d87e MP |
128 | { |
129 | ThrottleGroupMember *tgm = bs->opaque; | |
130 | throttle_group_co_io_limits_intercept(tgm, bytes, true); | |
131 | ||
132 | return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags); | |
133 | } | |
134 | ||
abaf8b75 KW |
135 | static int coroutine_fn GRAPH_RDLOCK |
136 | throttle_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, | |
137 | BdrvRequestFlags flags) | |
d8e7d87e MP |
138 | { |
139 | ThrottleGroupMember *tgm = bs->opaque; | |
140 | throttle_group_co_io_limits_intercept(tgm, bytes, true); | |
141 | ||
142 | return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags); | |
143 | } | |
144 | ||
9a5a1c62 EGE |
145 | static int coroutine_fn GRAPH_RDLOCK |
146 | throttle_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) | |
d8e7d87e MP |
147 | { |
148 | ThrottleGroupMember *tgm = bs->opaque; | |
149 | throttle_group_co_io_limits_intercept(tgm, bytes, true); | |
150 | ||
0b9fd3f4 | 151 | return bdrv_co_pdiscard(bs->file, offset, bytes); |
d8e7d87e MP |
152 | } |
153 | ||
b9b10c35 KW |
154 | static int coroutine_fn GRAPH_RDLOCK |
155 | throttle_co_pwritev_compressed(BlockDriverState *bs, int64_t offset, | |
156 | int64_t bytes, QEMUIOVector *qiov) | |
e7e754ae HR |
157 | { |
158 | return throttle_co_pwritev(bs, offset, bytes, qiov, | |
159 | BDRV_REQ_WRITE_COMPRESSED); | |
160 | } | |
161 | ||
88095349 | 162 | static int coroutine_fn GRAPH_RDLOCK throttle_co_flush(BlockDriverState *bs) |
d8e7d87e MP |
163 | { |
164 | return bdrv_co_flush(bs->file->bs); | |
165 | } | |
166 | ||
167 | static void throttle_detach_aio_context(BlockDriverState *bs) | |
168 | { | |
169 | ThrottleGroupMember *tgm = bs->opaque; | |
170 | throttle_group_detach_aio_context(tgm); | |
171 | } | |
172 | ||
173 | static void throttle_attach_aio_context(BlockDriverState *bs, | |
174 | AioContext *new_context) | |
175 | { | |
176 | ThrottleGroupMember *tgm = bs->opaque; | |
177 | throttle_group_attach_aio_context(tgm, new_context); | |
178 | } | |
179 | ||
180 | static int throttle_reopen_prepare(BDRVReopenState *reopen_state, | |
181 | BlockReopenQueue *queue, Error **errp) | |
182 | { | |
bc33c047 AG |
183 | int ret; |
184 | char *group = NULL; | |
d8e7d87e MP |
185 | |
186 | assert(reopen_state != NULL); | |
187 | assert(reopen_state->bs != NULL); | |
188 | ||
bc33c047 AG |
189 | ret = throttle_parse_options(reopen_state->options, &group, errp); |
190 | reopen_state->opaque = group; | |
191 | return ret; | |
d8e7d87e MP |
192 | } |
193 | ||
194 | static void throttle_reopen_commit(BDRVReopenState *reopen_state) | |
195 | { | |
bc33c047 AG |
196 | BlockDriverState *bs = reopen_state->bs; |
197 | ThrottleGroupMember *tgm = bs->opaque; | |
198 | char *group = reopen_state->opaque; | |
199 | ||
200 | assert(group); | |
d8e7d87e | 201 | |
bc33c047 AG |
202 | if (strcmp(group, throttle_group_get_name(tgm))) { |
203 | throttle_group_unregister_tgm(tgm); | |
204 | throttle_group_register_tgm(tgm, group, bdrv_get_aio_context(bs)); | |
205 | } | |
206 | g_free(reopen_state->opaque); | |
d8e7d87e MP |
207 | reopen_state->opaque = NULL; |
208 | } | |
209 | ||
210 | static void throttle_reopen_abort(BDRVReopenState *reopen_state) | |
211 | { | |
bc33c047 | 212 | g_free(reopen_state->opaque); |
d8e7d87e MP |
213 | reopen_state->opaque = NULL; |
214 | } | |
215 | ||
5e8ac217 | 216 | static void throttle_drain_begin(BlockDriverState *bs) |
b867eaa1 MP |
217 | { |
218 | ThrottleGroupMember *tgm = bs->opaque; | |
d73415a3 | 219 | if (qatomic_fetch_inc(&tgm->io_limits_disabled) == 0) { |
b867eaa1 MP |
220 | throttle_group_restart_tgm(tgm); |
221 | } | |
222 | } | |
223 | ||
5e8ac217 | 224 | static void throttle_drain_end(BlockDriverState *bs) |
b867eaa1 MP |
225 | { |
226 | ThrottleGroupMember *tgm = bs->opaque; | |
227 | assert(tgm->io_limits_disabled); | |
d73415a3 | 228 | qatomic_dec(&tgm->io_limits_disabled); |
b867eaa1 MP |
229 | } |
230 | ||
2654267c HR |
231 | static const char *const throttle_strong_runtime_opts[] = { |
232 | QEMU_OPT_THROTTLE_GROUP_NAME, | |
233 | ||
234 | NULL | |
235 | }; | |
236 | ||
d8e7d87e MP |
237 | static BlockDriver bdrv_throttle = { |
238 | .format_name = "throttle", | |
d8e7d87e MP |
239 | .instance_size = sizeof(ThrottleGroupMember), |
240 | ||
a7328ba5 | 241 | .bdrv_open = throttle_open, |
d8e7d87e MP |
242 | .bdrv_close = throttle_close, |
243 | .bdrv_co_flush = throttle_co_flush, | |
244 | ||
69dca43d | 245 | .bdrv_child_perm = bdrv_default_perms, |
d8e7d87e | 246 | |
c86422c5 | 247 | .bdrv_co_getlength = throttle_co_getlength, |
d8e7d87e MP |
248 | |
249 | .bdrv_co_preadv = throttle_co_preadv, | |
250 | .bdrv_co_pwritev = throttle_co_pwritev, | |
251 | ||
252 | .bdrv_co_pwrite_zeroes = throttle_co_pwrite_zeroes, | |
253 | .bdrv_co_pdiscard = throttle_co_pdiscard, | |
e7e754ae | 254 | .bdrv_co_pwritev_compressed = throttle_co_pwritev_compressed, |
d8e7d87e | 255 | |
d8e7d87e MP |
256 | .bdrv_attach_aio_context = throttle_attach_aio_context, |
257 | .bdrv_detach_aio_context = throttle_detach_aio_context, | |
258 | ||
259 | .bdrv_reopen_prepare = throttle_reopen_prepare, | |
260 | .bdrv_reopen_commit = throttle_reopen_commit, | |
261 | .bdrv_reopen_abort = throttle_reopen_abort, | |
d8e7d87e | 262 | |
5e8ac217 KW |
263 | .bdrv_drain_begin = throttle_drain_begin, |
264 | .bdrv_drain_end = throttle_drain_end, | |
b867eaa1 | 265 | |
d8e7d87e | 266 | .is_filter = true, |
2654267c | 267 | .strong_runtime_opts = throttle_strong_runtime_opts, |
d8e7d87e MP |
268 | }; |
269 | ||
270 | static void bdrv_throttle_init(void) | |
271 | { | |
272 | bdrv_register(&bdrv_throttle); | |
273 | } | |
274 | ||
275 | block_init(bdrv_throttle_init); |