root / aio-posix.c @ 3bd88451
History | View | Annotate | Download (6.7 kB)
1 | a76bab49 | aliguori | /*
|
---|---|---|---|
2 | a76bab49 | aliguori | * QEMU aio implementation
|
3 | a76bab49 | aliguori | *
|
4 | a76bab49 | aliguori | * Copyright IBM, Corp. 2008
|
5 | a76bab49 | aliguori | *
|
6 | a76bab49 | aliguori | * Authors:
|
7 | a76bab49 | aliguori | * Anthony Liguori <aliguori@us.ibm.com>
|
8 | a76bab49 | aliguori | *
|
9 | a76bab49 | aliguori | * This work is licensed under the terms of the GNU GPL, version 2. See
|
10 | a76bab49 | aliguori | * the COPYING file in the top-level directory.
|
11 | a76bab49 | aliguori | *
|
12 | 6b620ca3 | Paolo Bonzini | * Contributions after 2012-01-13 are licensed under the terms of the
|
13 | 6b620ca3 | Paolo Bonzini | * GNU GPL, version 2 or (at your option) any later version.
|
14 | a76bab49 | aliguori | */
|
15 | a76bab49 | aliguori | |
16 | a76bab49 | aliguori | #include "qemu-common.h" |
17 | 737e150e | Paolo Bonzini | #include "block/block.h" |
18 | 1de7afc9 | Paolo Bonzini | #include "qemu/queue.h" |
19 | 1de7afc9 | Paolo Bonzini | #include "qemu/sockets.h" |
20 | a76bab49 | aliguori | |
21 | a76bab49 | aliguori | struct AioHandler
|
22 | a76bab49 | aliguori | { |
23 | cd9ba1eb | Paolo Bonzini | GPollFD pfd; |
24 | a76bab49 | aliguori | IOHandler *io_read; |
25 | a76bab49 | aliguori | IOHandler *io_write; |
26 | a76bab49 | aliguori | AioFlushHandler *io_flush; |
27 | a76bab49 | aliguori | int deleted;
|
28 | 6b5f8762 | Stefan Hajnoczi | int pollfds_idx;
|
29 | a76bab49 | aliguori | void *opaque;
|
30 | 72cf2d4f | Blue Swirl | QLIST_ENTRY(AioHandler) node; |
31 | a76bab49 | aliguori | }; |
32 | a76bab49 | aliguori | |
33 | a915f4bc | Paolo Bonzini | static AioHandler *find_aio_handler(AioContext *ctx, int fd) |
34 | a76bab49 | aliguori | { |
35 | a76bab49 | aliguori | AioHandler *node; |
36 | a76bab49 | aliguori | |
37 | a915f4bc | Paolo Bonzini | QLIST_FOREACH(node, &ctx->aio_handlers, node) { |
38 | cd9ba1eb | Paolo Bonzini | if (node->pfd.fd == fd)
|
39 | 79d5ca56 | Alexander Graf | if (!node->deleted)
|
40 | 79d5ca56 | Alexander Graf | return node;
|
41 | a76bab49 | aliguori | } |
42 | a76bab49 | aliguori | |
43 | a76bab49 | aliguori | return NULL; |
44 | a76bab49 | aliguori | } |
45 | a76bab49 | aliguori | |
46 | a915f4bc | Paolo Bonzini | void aio_set_fd_handler(AioContext *ctx,
|
47 | a915f4bc | Paolo Bonzini | int fd,
|
48 | a915f4bc | Paolo Bonzini | IOHandler *io_read, |
49 | a915f4bc | Paolo Bonzini | IOHandler *io_write, |
50 | a915f4bc | Paolo Bonzini | AioFlushHandler *io_flush, |
51 | a915f4bc | Paolo Bonzini | void *opaque)
|
52 | a76bab49 | aliguori | { |
53 | a76bab49 | aliguori | AioHandler *node; |
54 | a76bab49 | aliguori | |
55 | a915f4bc | Paolo Bonzini | node = find_aio_handler(ctx, fd); |
56 | a76bab49 | aliguori | |
57 | a76bab49 | aliguori | /* Are we deleting the fd handler? */
|
58 | a76bab49 | aliguori | if (!io_read && !io_write) {
|
59 | a76bab49 | aliguori | if (node) {
|
60 | e3713e00 | Paolo Bonzini | g_source_remove_poll(&ctx->source, &node->pfd); |
61 | e3713e00 | Paolo Bonzini | |
62 | a76bab49 | aliguori | /* If the lock is held, just mark the node as deleted */
|
63 | cd9ba1eb | Paolo Bonzini | if (ctx->walking_handlers) {
|
64 | a76bab49 | aliguori | node->deleted = 1;
|
65 | cd9ba1eb | Paolo Bonzini | node->pfd.revents = 0;
|
66 | cd9ba1eb | Paolo Bonzini | } else {
|
67 | a76bab49 | aliguori | /* Otherwise, delete it for real. We can't just mark it as
|
68 | a76bab49 | aliguori | * deleted because deleted nodes are only cleaned up after
|
69 | a76bab49 | aliguori | * releasing the walking_handlers lock.
|
70 | a76bab49 | aliguori | */
|
71 | 72cf2d4f | Blue Swirl | QLIST_REMOVE(node, node); |
72 | 7267c094 | Anthony Liguori | g_free(node); |
73 | a76bab49 | aliguori | } |
74 | a76bab49 | aliguori | } |
75 | a76bab49 | aliguori | } else {
|
76 | a76bab49 | aliguori | if (node == NULL) { |
77 | a76bab49 | aliguori | /* Alloc and insert if it's not already there */
|
78 | 7267c094 | Anthony Liguori | node = g_malloc0(sizeof(AioHandler));
|
79 | cd9ba1eb | Paolo Bonzini | node->pfd.fd = fd; |
80 | a915f4bc | Paolo Bonzini | QLIST_INSERT_HEAD(&ctx->aio_handlers, node, node); |
81 | e3713e00 | Paolo Bonzini | |
82 | e3713e00 | Paolo Bonzini | g_source_add_poll(&ctx->source, &node->pfd); |
83 | a76bab49 | aliguori | } |
84 | a76bab49 | aliguori | /* Update handler with latest information */
|
85 | a76bab49 | aliguori | node->io_read = io_read; |
86 | a76bab49 | aliguori | node->io_write = io_write; |
87 | a76bab49 | aliguori | node->io_flush = io_flush; |
88 | a76bab49 | aliguori | node->opaque = opaque; |
89 | 6b5f8762 | Stefan Hajnoczi | node->pollfds_idx = -1;
|
90 | cd9ba1eb | Paolo Bonzini | |
91 | b5a01a70 | Stefan Hajnoczi | node->pfd.events = (io_read ? G_IO_IN | G_IO_HUP | G_IO_ERR : 0);
|
92 | b5a01a70 | Stefan Hajnoczi | node->pfd.events |= (io_write ? G_IO_OUT | G_IO_ERR : 0);
|
93 | a76bab49 | aliguori | } |
94 | 7ed2b24c | Paolo Bonzini | |
95 | 7ed2b24c | Paolo Bonzini | aio_notify(ctx); |
96 | 9958c351 | Paolo Bonzini | } |
97 | 9958c351 | Paolo Bonzini | |
98 | a915f4bc | Paolo Bonzini | void aio_set_event_notifier(AioContext *ctx,
|
99 | a915f4bc | Paolo Bonzini | EventNotifier *notifier, |
100 | a915f4bc | Paolo Bonzini | EventNotifierHandler *io_read, |
101 | a915f4bc | Paolo Bonzini | AioFlushEventNotifierHandler *io_flush) |
102 | a76bab49 | aliguori | { |
103 | a915f4bc | Paolo Bonzini | aio_set_fd_handler(ctx, event_notifier_get_fd(notifier), |
104 | a915f4bc | Paolo Bonzini | (IOHandler *)io_read, NULL,
|
105 | a915f4bc | Paolo Bonzini | (AioFlushHandler *)io_flush, notifier); |
106 | a76bab49 | aliguori | } |
107 | a76bab49 | aliguori | |
108 | cd9ba1eb | Paolo Bonzini | bool aio_pending(AioContext *ctx)
|
109 | cd9ba1eb | Paolo Bonzini | { |
110 | cd9ba1eb | Paolo Bonzini | AioHandler *node; |
111 | cd9ba1eb | Paolo Bonzini | |
112 | cd9ba1eb | Paolo Bonzini | QLIST_FOREACH(node, &ctx->aio_handlers, node) { |
113 | cd9ba1eb | Paolo Bonzini | int revents;
|
114 | cd9ba1eb | Paolo Bonzini | |
115 | cd9ba1eb | Paolo Bonzini | revents = node->pfd.revents & node->pfd.events; |
116 | cd9ba1eb | Paolo Bonzini | if (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR) && node->io_read) {
|
117 | cd9ba1eb | Paolo Bonzini | return true; |
118 | cd9ba1eb | Paolo Bonzini | } |
119 | cd9ba1eb | Paolo Bonzini | if (revents & (G_IO_OUT | G_IO_ERR) && node->io_write) {
|
120 | cd9ba1eb | Paolo Bonzini | return true; |
121 | cd9ba1eb | Paolo Bonzini | } |
122 | cd9ba1eb | Paolo Bonzini | } |
123 | cd9ba1eb | Paolo Bonzini | |
124 | cd9ba1eb | Paolo Bonzini | return false; |
125 | cd9ba1eb | Paolo Bonzini | } |
126 | cd9ba1eb | Paolo Bonzini | |
127 | d0c8d2c0 | Stefan Hajnoczi | static bool aio_dispatch(AioContext *ctx) |
128 | a76bab49 | aliguori | { |
129 | 9eb0bfca | Paolo Bonzini | AioHandler *node; |
130 | d0c8d2c0 | Stefan Hajnoczi | bool progress = false; |
131 | 7c0628b2 | Paolo Bonzini | |
132 | cd9ba1eb | Paolo Bonzini | /*
|
133 | cd9ba1eb | Paolo Bonzini | * We have to walk very carefully in case qemu_aio_set_fd_handler is
|
134 | cd9ba1eb | Paolo Bonzini | * called while we're walking.
|
135 | cd9ba1eb | Paolo Bonzini | */
|
136 | cd9ba1eb | Paolo Bonzini | node = QLIST_FIRST(&ctx->aio_handlers); |
137 | cd9ba1eb | Paolo Bonzini | while (node) {
|
138 | cd9ba1eb | Paolo Bonzini | AioHandler *tmp; |
139 | cd9ba1eb | Paolo Bonzini | int revents;
|
140 | cd9ba1eb | Paolo Bonzini | |
141 | cd9ba1eb | Paolo Bonzini | ctx->walking_handlers++; |
142 | cd9ba1eb | Paolo Bonzini | |
143 | cd9ba1eb | Paolo Bonzini | revents = node->pfd.revents & node->pfd.events; |
144 | cd9ba1eb | Paolo Bonzini | node->pfd.revents = 0;
|
145 | cd9ba1eb | Paolo Bonzini | |
146 | d0c8d2c0 | Stefan Hajnoczi | if (!node->deleted &&
|
147 | d0c8d2c0 | Stefan Hajnoczi | (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR)) && |
148 | d0c8d2c0 | Stefan Hajnoczi | node->io_read) { |
149 | cd9ba1eb | Paolo Bonzini | node->io_read(node->opaque); |
150 | cd9ba1eb | Paolo Bonzini | progress = true;
|
151 | cd9ba1eb | Paolo Bonzini | } |
152 | d0c8d2c0 | Stefan Hajnoczi | if (!node->deleted &&
|
153 | d0c8d2c0 | Stefan Hajnoczi | (revents & (G_IO_OUT | G_IO_ERR)) && |
154 | d0c8d2c0 | Stefan Hajnoczi | node->io_write) { |
155 | cd9ba1eb | Paolo Bonzini | node->io_write(node->opaque); |
156 | cd9ba1eb | Paolo Bonzini | progress = true;
|
157 | cd9ba1eb | Paolo Bonzini | } |
158 | cd9ba1eb | Paolo Bonzini | |
159 | cd9ba1eb | Paolo Bonzini | tmp = node; |
160 | cd9ba1eb | Paolo Bonzini | node = QLIST_NEXT(node, node); |
161 | cd9ba1eb | Paolo Bonzini | |
162 | cd9ba1eb | Paolo Bonzini | ctx->walking_handlers--; |
163 | cd9ba1eb | Paolo Bonzini | |
164 | cd9ba1eb | Paolo Bonzini | if (!ctx->walking_handlers && tmp->deleted) {
|
165 | cd9ba1eb | Paolo Bonzini | QLIST_REMOVE(tmp, node); |
166 | cd9ba1eb | Paolo Bonzini | g_free(tmp); |
167 | cd9ba1eb | Paolo Bonzini | } |
168 | cd9ba1eb | Paolo Bonzini | } |
169 | d0c8d2c0 | Stefan Hajnoczi | return progress;
|
170 | d0c8d2c0 | Stefan Hajnoczi | } |
171 | d0c8d2c0 | Stefan Hajnoczi | |
172 | d0c8d2c0 | Stefan Hajnoczi | bool aio_poll(AioContext *ctx, bool blocking) |
173 | d0c8d2c0 | Stefan Hajnoczi | { |
174 | d0c8d2c0 | Stefan Hajnoczi | AioHandler *node; |
175 | d0c8d2c0 | Stefan Hajnoczi | int ret;
|
176 | d0c8d2c0 | Stefan Hajnoczi | bool busy, progress;
|
177 | d0c8d2c0 | Stefan Hajnoczi | |
178 | d0c8d2c0 | Stefan Hajnoczi | progress = false;
|
179 | d0c8d2c0 | Stefan Hajnoczi | |
180 | d0c8d2c0 | Stefan Hajnoczi | /*
|
181 | d0c8d2c0 | Stefan Hajnoczi | * If there are callbacks left that have been queued, we need to call them.
|
182 | d0c8d2c0 | Stefan Hajnoczi | * Do not call select in this case, because it is possible that the caller
|
183 | d0c8d2c0 | Stefan Hajnoczi | * does not need a complete flush (as is the case for qemu_aio_wait loops).
|
184 | d0c8d2c0 | Stefan Hajnoczi | */
|
185 | d0c8d2c0 | Stefan Hajnoczi | if (aio_bh_poll(ctx)) {
|
186 | d0c8d2c0 | Stefan Hajnoczi | blocking = false;
|
187 | d0c8d2c0 | Stefan Hajnoczi | progress = true;
|
188 | d0c8d2c0 | Stefan Hajnoczi | } |
189 | d0c8d2c0 | Stefan Hajnoczi | |
190 | d0c8d2c0 | Stefan Hajnoczi | if (aio_dispatch(ctx)) {
|
191 | d0c8d2c0 | Stefan Hajnoczi | progress = true;
|
192 | d0c8d2c0 | Stefan Hajnoczi | } |
193 | cd9ba1eb | Paolo Bonzini | |
194 | 7c0628b2 | Paolo Bonzini | if (progress && !blocking) {
|
195 | bcdc1857 | Paolo Bonzini | return true; |
196 | bafbd6a1 | Paolo Bonzini | } |
197 | 8febfa26 | Kevin Wolf | |
198 | a915f4bc | Paolo Bonzini | ctx->walking_handlers++; |
199 | a76bab49 | aliguori | |
200 | 6b5f8762 | Stefan Hajnoczi | g_array_set_size(ctx->pollfds, 0);
|
201 | a76bab49 | aliguori | |
202 | 6b5f8762 | Stefan Hajnoczi | /* fill pollfds */
|
203 | 9eb0bfca | Paolo Bonzini | busy = false;
|
204 | a915f4bc | Paolo Bonzini | QLIST_FOREACH(node, &ctx->aio_handlers, node) { |
205 | 6b5f8762 | Stefan Hajnoczi | node->pollfds_idx = -1;
|
206 | 6b5f8762 | Stefan Hajnoczi | |
207 | 9eb0bfca | Paolo Bonzini | /* If there aren't pending AIO operations, don't invoke callbacks.
|
208 | 9eb0bfca | Paolo Bonzini | * Otherwise, if there are no AIO requests, qemu_aio_wait() would
|
209 | 9eb0bfca | Paolo Bonzini | * wait indefinitely.
|
210 | 9eb0bfca | Paolo Bonzini | */
|
211 | 4231c88d | Paolo Bonzini | if (!node->deleted && node->io_flush) {
|
212 | 9eb0bfca | Paolo Bonzini | if (node->io_flush(node->opaque) == 0) { |
213 | 9eb0bfca | Paolo Bonzini | continue;
|
214 | a76bab49 | aliguori | } |
215 | 9eb0bfca | Paolo Bonzini | busy = true;
|
216 | 9eb0bfca | Paolo Bonzini | } |
217 | 6b5f8762 | Stefan Hajnoczi | if (!node->deleted && node->pfd.events) {
|
218 | 6b5f8762 | Stefan Hajnoczi | GPollFD pfd = { |
219 | 6b5f8762 | Stefan Hajnoczi | .fd = node->pfd.fd, |
220 | 6b5f8762 | Stefan Hajnoczi | .events = node->pfd.events, |
221 | 6b5f8762 | Stefan Hajnoczi | }; |
222 | 6b5f8762 | Stefan Hajnoczi | node->pollfds_idx = ctx->pollfds->len; |
223 | 6b5f8762 | Stefan Hajnoczi | g_array_append_val(ctx->pollfds, pfd); |
224 | 9eb0bfca | Paolo Bonzini | } |
225 | 9eb0bfca | Paolo Bonzini | } |
226 | a76bab49 | aliguori | |
227 | a915f4bc | Paolo Bonzini | ctx->walking_handlers--; |
228 | a76bab49 | aliguori | |
229 | 9eb0bfca | Paolo Bonzini | /* No AIO operations? Get us out of here */
|
230 | 9eb0bfca | Paolo Bonzini | if (!busy) {
|
231 | 7c0628b2 | Paolo Bonzini | return progress;
|
232 | 9eb0bfca | Paolo Bonzini | } |
233 | a76bab49 | aliguori | |
234 | 9eb0bfca | Paolo Bonzini | /* wait until next event */
|
235 | 6b5f8762 | Stefan Hajnoczi | ret = g_poll((GPollFD *)ctx->pollfds->data, |
236 | 6b5f8762 | Stefan Hajnoczi | ctx->pollfds->len, |
237 | 6b5f8762 | Stefan Hajnoczi | blocking ? -1 : 0); |
238 | 9eb0bfca | Paolo Bonzini | |
239 | 9eb0bfca | Paolo Bonzini | /* if we have any readable fds, dispatch event */
|
240 | 9eb0bfca | Paolo Bonzini | if (ret > 0) { |
241 | 6b5f8762 | Stefan Hajnoczi | QLIST_FOREACH(node, &ctx->aio_handlers, node) { |
242 | 6b5f8762 | Stefan Hajnoczi | if (node->pollfds_idx != -1) { |
243 | 6b5f8762 | Stefan Hajnoczi | GPollFD *pfd = &g_array_index(ctx->pollfds, GPollFD, |
244 | 6b5f8762 | Stefan Hajnoczi | node->pollfds_idx); |
245 | 6b5f8762 | Stefan Hajnoczi | node->pfd.revents = pfd->revents; |
246 | 9eb0bfca | Paolo Bonzini | } |
247 | a76bab49 | aliguori | } |
248 | 6b5f8762 | Stefan Hajnoczi | if (aio_dispatch(ctx)) {
|
249 | 6b5f8762 | Stefan Hajnoczi | progress = true;
|
250 | 6b5f8762 | Stefan Hajnoczi | } |
251 | 9eb0bfca | Paolo Bonzini | } |
252 | bcdc1857 | Paolo Bonzini | |
253 | 2ea9b58f | Kevin Wolf | assert(progress || busy); |
254 | 2ea9b58f | Kevin Wolf | return true; |
255 | a76bab49 | aliguori | } |