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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" | |
21 | #include "block/throttle-groups.h" | |
0b8fa32f | 22 | #include "qemu/module.h" |
922a01a0 | 23 | #include "qemu/option.h" |
d8e7d87e MP |
24 | #include "qemu/throttle-options.h" |
25 | #include "qapi/error.h" | |
26 | ||
27 | static QemuOptsList throttle_opts = { | |
28 | .name = "throttle", | |
29 | .head = QTAILQ_HEAD_INITIALIZER(throttle_opts.head), | |
30 | .desc = { | |
31 | { | |
32 | .name = QEMU_OPT_THROTTLE_GROUP_NAME, | |
33 | .type = QEMU_OPT_STRING, | |
34 | .help = "Name of the throttle group", | |
35 | }, | |
36 | { /* end of list */ } | |
37 | }, | |
38 | }; | |
39 | ||
bc33c047 AG |
40 | /* |
41 | * If this function succeeds then the throttle group name is stored in | |
42 | * @group and must be freed by the caller. | |
43 | * If there's an error then @group remains unmodified. | |
44 | */ | |
45 | static int throttle_parse_options(QDict *options, char **group, Error **errp) | |
d8e7d87e MP |
46 | { |
47 | int ret; | |
48 | const char *group_name; | |
49 | Error *local_err = NULL; | |
50 | QemuOpts *opts = qemu_opts_create(&throttle_opts, NULL, 0, &error_abort); | |
51 | ||
52 | qemu_opts_absorb_qdict(opts, options, &local_err); | |
53 | if (local_err) { | |
54 | error_propagate(errp, local_err); | |
55 | ret = -EINVAL; | |
56 | goto fin; | |
57 | } | |
58 | ||
59 | group_name = qemu_opt_get(opts, QEMU_OPT_THROTTLE_GROUP_NAME); | |
60 | if (!group_name) { | |
61 | error_setg(errp, "Please specify a throttle group"); | |
62 | ret = -EINVAL; | |
63 | goto fin; | |
64 | } else if (!throttle_group_exists(group_name)) { | |
65 | error_setg(errp, "Throttle group '%s' does not exist", group_name); | |
66 | ret = -EINVAL; | |
67 | goto fin; | |
68 | } | |
69 | ||
bc33c047 | 70 | *group = g_strdup(group_name); |
d8e7d87e MP |
71 | ret = 0; |
72 | fin: | |
73 | qemu_opts_del(opts); | |
74 | return ret; | |
75 | } | |
76 | ||
77 | static int throttle_open(BlockDriverState *bs, QDict *options, | |
78 | int flags, Error **errp) | |
79 | { | |
80 | ThrottleGroupMember *tgm = bs->opaque; | |
bc33c047 AG |
81 | char *group; |
82 | int ret; | |
d8e7d87e | 83 | |
b3af2af4 HR |
84 | bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds, |
85 | BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, | |
86 | false, errp); | |
d8e7d87e MP |
87 | if (!bs->file) { |
88 | return -EINVAL; | |
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 | ||
112 | static int64_t throttle_getlength(BlockDriverState *bs) | |
113 | { | |
114 | return bdrv_getlength(bs->file->bs); | |
115 | } | |
116 | ||
117 | static int coroutine_fn throttle_co_preadv(BlockDriverState *bs, | |
118 | uint64_t offset, uint64_t bytes, | |
119 | QEMUIOVector *qiov, int flags) | |
120 | { | |
121 | ||
122 | ThrottleGroupMember *tgm = bs->opaque; | |
123 | throttle_group_co_io_limits_intercept(tgm, bytes, false); | |
124 | ||
125 | return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); | |
126 | } | |
127 | ||
128 | static int coroutine_fn throttle_co_pwritev(BlockDriverState *bs, | |
129 | uint64_t offset, uint64_t bytes, | |
130 | QEMUIOVector *qiov, int flags) | |
131 | { | |
132 | ThrottleGroupMember *tgm = bs->opaque; | |
133 | throttle_group_co_io_limits_intercept(tgm, bytes, true); | |
134 | ||
135 | return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags); | |
136 | } | |
137 | ||
138 | static int coroutine_fn throttle_co_pwrite_zeroes(BlockDriverState *bs, | |
139 | int64_t offset, int bytes, | |
140 | BdrvRequestFlags flags) | |
141 | { | |
142 | ThrottleGroupMember *tgm = bs->opaque; | |
143 | throttle_group_co_io_limits_intercept(tgm, bytes, true); | |
144 | ||
145 | return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags); | |
146 | } | |
147 | ||
148 | static int coroutine_fn throttle_co_pdiscard(BlockDriverState *bs, | |
149 | int64_t offset, int bytes) | |
150 | { | |
151 | ThrottleGroupMember *tgm = bs->opaque; | |
152 | throttle_group_co_io_limits_intercept(tgm, bytes, true); | |
153 | ||
0b9fd3f4 | 154 | return bdrv_co_pdiscard(bs->file, offset, bytes); |
d8e7d87e MP |
155 | } |
156 | ||
157 | static int throttle_co_flush(BlockDriverState *bs) | |
158 | { | |
159 | return bdrv_co_flush(bs->file->bs); | |
160 | } | |
161 | ||
162 | static void throttle_detach_aio_context(BlockDriverState *bs) | |
163 | { | |
164 | ThrottleGroupMember *tgm = bs->opaque; | |
165 | throttle_group_detach_aio_context(tgm); | |
166 | } | |
167 | ||
168 | static void throttle_attach_aio_context(BlockDriverState *bs, | |
169 | AioContext *new_context) | |
170 | { | |
171 | ThrottleGroupMember *tgm = bs->opaque; | |
172 | throttle_group_attach_aio_context(tgm, new_context); | |
173 | } | |
174 | ||
175 | static int throttle_reopen_prepare(BDRVReopenState *reopen_state, | |
176 | BlockReopenQueue *queue, Error **errp) | |
177 | { | |
bc33c047 AG |
178 | int ret; |
179 | char *group = NULL; | |
d8e7d87e MP |
180 | |
181 | assert(reopen_state != NULL); | |
182 | assert(reopen_state->bs != NULL); | |
183 | ||
bc33c047 AG |
184 | ret = throttle_parse_options(reopen_state->options, &group, errp); |
185 | reopen_state->opaque = group; | |
186 | return ret; | |
d8e7d87e MP |
187 | } |
188 | ||
189 | static void throttle_reopen_commit(BDRVReopenState *reopen_state) | |
190 | { | |
bc33c047 AG |
191 | BlockDriverState *bs = reopen_state->bs; |
192 | ThrottleGroupMember *tgm = bs->opaque; | |
193 | char *group = reopen_state->opaque; | |
194 | ||
195 | assert(group); | |
d8e7d87e | 196 | |
bc33c047 AG |
197 | if (strcmp(group, throttle_group_get_name(tgm))) { |
198 | throttle_group_unregister_tgm(tgm); | |
199 | throttle_group_register_tgm(tgm, group, bdrv_get_aio_context(bs)); | |
200 | } | |
201 | g_free(reopen_state->opaque); | |
d8e7d87e MP |
202 | reopen_state->opaque = NULL; |
203 | } | |
204 | ||
205 | static void throttle_reopen_abort(BDRVReopenState *reopen_state) | |
206 | { | |
bc33c047 | 207 | g_free(reopen_state->opaque); |
d8e7d87e MP |
208 | reopen_state->opaque = NULL; |
209 | } | |
210 | ||
b867eaa1 MP |
211 | static void coroutine_fn throttle_co_drain_begin(BlockDriverState *bs) |
212 | { | |
213 | ThrottleGroupMember *tgm = bs->opaque; | |
214 | if (atomic_fetch_inc(&tgm->io_limits_disabled) == 0) { | |
215 | throttle_group_restart_tgm(tgm); | |
216 | } | |
217 | } | |
218 | ||
219 | static void coroutine_fn throttle_co_drain_end(BlockDriverState *bs) | |
220 | { | |
221 | ThrottleGroupMember *tgm = bs->opaque; | |
222 | assert(tgm->io_limits_disabled); | |
223 | atomic_dec(&tgm->io_limits_disabled); | |
224 | } | |
225 | ||
2654267c HR |
226 | static const char *const throttle_strong_runtime_opts[] = { |
227 | QEMU_OPT_THROTTLE_GROUP_NAME, | |
228 | ||
229 | NULL | |
230 | }; | |
231 | ||
d8e7d87e MP |
232 | static BlockDriver bdrv_throttle = { |
233 | .format_name = "throttle", | |
d8e7d87e MP |
234 | .instance_size = sizeof(ThrottleGroupMember), |
235 | ||
a7328ba5 | 236 | .bdrv_open = throttle_open, |
d8e7d87e MP |
237 | .bdrv_close = throttle_close, |
238 | .bdrv_co_flush = throttle_co_flush, | |
239 | ||
240 | .bdrv_child_perm = bdrv_filter_default_perms, | |
241 | ||
242 | .bdrv_getlength = throttle_getlength, | |
243 | ||
244 | .bdrv_co_preadv = throttle_co_preadv, | |
245 | .bdrv_co_pwritev = throttle_co_pwritev, | |
246 | ||
247 | .bdrv_co_pwrite_zeroes = throttle_co_pwrite_zeroes, | |
248 | .bdrv_co_pdiscard = throttle_co_pdiscard, | |
249 | ||
d8e7d87e MP |
250 | .bdrv_attach_aio_context = throttle_attach_aio_context, |
251 | .bdrv_detach_aio_context = throttle_detach_aio_context, | |
252 | ||
253 | .bdrv_reopen_prepare = throttle_reopen_prepare, | |
254 | .bdrv_reopen_commit = throttle_reopen_commit, | |
255 | .bdrv_reopen_abort = throttle_reopen_abort, | |
3e4d0e72 | 256 | .bdrv_co_block_status = bdrv_co_block_status_from_file, |
d8e7d87e | 257 | |
b867eaa1 MP |
258 | .bdrv_co_drain_begin = throttle_co_drain_begin, |
259 | .bdrv_co_drain_end = throttle_co_drain_end, | |
260 | ||
d8e7d87e | 261 | .is_filter = true, |
2654267c | 262 | .strong_runtime_opts = throttle_strong_runtime_opts, |
d8e7d87e MP |
263 | }; |
264 | ||
265 | static void bdrv_throttle_init(void) | |
266 | { | |
267 | bdrv_register(&bdrv_throttle); | |
268 | } | |
269 | ||
270 | block_init(bdrv_throttle_init); |