block: honor BDRV_O_ALLOW_RDWR when clearing bs->read_only
[qemu.git] / block / win32-aio.c
1 /*
2 * Block driver for RAW files (win32)
3 *
4 * Copyright (c) 2006 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 #include "qemu/osdep.h"
25 #include "qemu-common.h"
26 #include "qemu/timer.h"
27 #include "block/block_int.h"
28 #include "qemu/module.h"
29 #include "block/aio.h"
30 #include "block/raw-aio.h"
31 #include "qemu/event_notifier.h"
32 #include "qemu/iov.h"
33 #include <windows.h>
34 #include <winioctl.h>
35
36 #define FTYPE_FILE 0
37 #define FTYPE_CD 1
38 #define FTYPE_HARDDISK 2
39
40 struct QEMUWin32AIOState {
41 HANDLE hIOCP;
42 EventNotifier e;
43 int count;
44 AioContext *aio_ctx;
45 };
46
47 typedef struct QEMUWin32AIOCB {
48 BlockAIOCB common;
49 struct QEMUWin32AIOState *ctx;
50 int nbytes;
51 OVERLAPPED ov;
52 QEMUIOVector *qiov;
53 void *buf;
54 bool is_read;
55 bool is_linear;
56 } QEMUWin32AIOCB;
57
58 /*
59 * Completes an AIO request (calls the callback and frees the ACB).
60 */
61 static void win32_aio_process_completion(QEMUWin32AIOState *s,
62 QEMUWin32AIOCB *waiocb, DWORD count)
63 {
64 int ret;
65 s->count--;
66
67 if (waiocb->ov.Internal != 0) {
68 ret = -EIO;
69 } else {
70 ret = 0;
71 if (count < waiocb->nbytes) {
72 /* Short reads mean EOF, pad with zeros. */
73 if (waiocb->is_read) {
74 qemu_iovec_memset(waiocb->qiov, count, 0,
75 waiocb->qiov->size - count);
76 } else {
77 ret = -EINVAL;
78 }
79 }
80 }
81
82 if (!waiocb->is_linear) {
83 if (ret == 0 && waiocb->is_read) {
84 QEMUIOVector *qiov = waiocb->qiov;
85 iov_from_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
86 }
87 qemu_vfree(waiocb->buf);
88 }
89
90 waiocb->common.cb(waiocb->common.opaque, ret);
91 qemu_aio_unref(waiocb);
92 }
93
94 static void win32_aio_completion_cb(EventNotifier *e)
95 {
96 QEMUWin32AIOState *s = container_of(e, QEMUWin32AIOState, e);
97 DWORD count;
98 ULONG_PTR key;
99 OVERLAPPED *ov;
100
101 event_notifier_test_and_clear(&s->e);
102 while (GetQueuedCompletionStatus(s->hIOCP, &count, &key, &ov, 0)) {
103 QEMUWin32AIOCB *waiocb = container_of(ov, QEMUWin32AIOCB, ov);
104
105 win32_aio_process_completion(s, waiocb, count);
106 }
107 }
108
109 static const AIOCBInfo win32_aiocb_info = {
110 .aiocb_size = sizeof(QEMUWin32AIOCB),
111 };
112
113 BlockAIOCB *win32_aio_submit(BlockDriverState *bs,
114 QEMUWin32AIOState *aio, HANDLE hfile,
115 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
116 BlockCompletionFunc *cb, void *opaque, int type)
117 {
118 struct QEMUWin32AIOCB *waiocb;
119 uint64_t offset = sector_num * 512;
120 DWORD rc;
121
122 waiocb = qemu_aio_get(&win32_aiocb_info, bs, cb, opaque);
123 waiocb->nbytes = nb_sectors * 512;
124 waiocb->qiov = qiov;
125 waiocb->is_read = (type == QEMU_AIO_READ);
126
127 if (qiov->niov > 1) {
128 waiocb->buf = qemu_try_blockalign(bs, qiov->size);
129 if (waiocb->buf == NULL) {
130 goto out;
131 }
132 if (type & QEMU_AIO_WRITE) {
133 iov_to_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
134 }
135 waiocb->is_linear = false;
136 } else {
137 waiocb->buf = qiov->iov[0].iov_base;
138 waiocb->is_linear = true;
139 }
140
141 memset(&waiocb->ov, 0, sizeof(waiocb->ov));
142 waiocb->ov.Offset = (DWORD)offset;
143 waiocb->ov.OffsetHigh = (DWORD)(offset >> 32);
144 waiocb->ov.hEvent = event_notifier_get_handle(&aio->e);
145
146 aio->count++;
147
148 if (type & QEMU_AIO_READ) {
149 rc = ReadFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
150 } else {
151 rc = WriteFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
152 }
153 if(rc == 0 && GetLastError() != ERROR_IO_PENDING) {
154 goto out_dec_count;
155 }
156 return &waiocb->common;
157
158 out_dec_count:
159 aio->count--;
160 out:
161 qemu_aio_unref(waiocb);
162 return NULL;
163 }
164
165 int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile)
166 {
167 if (CreateIoCompletionPort(hfile, aio->hIOCP, (ULONG_PTR) 0, 0) == NULL) {
168 return -EINVAL;
169 } else {
170 return 0;
171 }
172 }
173
174 void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
175 AioContext *old_context)
176 {
177 aio_set_event_notifier(old_context, &aio->e, false, NULL, NULL);
178 aio->aio_ctx = NULL;
179 }
180
181 void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
182 AioContext *new_context)
183 {
184 aio->aio_ctx = new_context;
185 aio_set_event_notifier(new_context, &aio->e, false,
186 win32_aio_completion_cb, NULL);
187 }
188
189 QEMUWin32AIOState *win32_aio_init(void)
190 {
191 QEMUWin32AIOState *s;
192
193 s = g_malloc0(sizeof(*s));
194 if (event_notifier_init(&s->e, false) < 0) {
195 goto out_free_state;
196 }
197
198 s->hIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
199 if (s->hIOCP == NULL) {
200 goto out_close_efd;
201 }
202
203 return s;
204
205 out_close_efd:
206 event_notifier_cleanup(&s->e);
207 out_free_state:
208 g_free(s);
209 return NULL;
210 }
211
212 void win32_aio_cleanup(QEMUWin32AIOState *aio)
213 {
214 assert(!aio->aio_ctx);
215 CloseHandle(aio->hIOCP);
216 event_notifier_cleanup(&aio->e);
217 g_free(aio);
218 }