修改内核路径

hc

2024-05-14 bedbef8ad3e75a304af6361af235302bcc61d06b

 kernel/tools/hv/hv_fcopy_daemon.c
..
..
@@ -1,19 +1,10 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
1
2
 /*
2
3
  * An implementation of host to guest copy functionality for Linux.
3
4
  *
4
5
  * Copyright (C) 2014, Microsoft, Inc.
5
6
  *
6
7
  * Author : K. Y. Srinivasan <kys@microsoft.com>
7
- *
8
- * This program is free software; you can redistribute it and/or modify it
9
- * under the terms of the GNU General Public License version 2 as published
10
- * by the Free Software Foundation.
11
- *
12
- * This program is distributed in the hope that it will be useful, but
13
- * WITHOUT ANY WARRANTY; without even the implied warranty of
14
- * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
15
- * NON INFRINGEMENT.  See the GNU General Public License for more
16
- * details.
17
8
  */
18
9
 
19
10
 
..
..
@@ -89,6 +80,8 @@
89
80
 
90
81
 	error = 0;
91
82
 done:
83
+	if (error)
84
+		target_fname[0] = '\0';
92
85
 	return error;
93
86
 }
94
87
 
..
..
@@ -117,15 +110,29 @@
117
110
 	return ret;
118
111
 }
119
112
 
113
+/*
114
+ * Reset target_fname to "" in the two below functions for hibernation: if
115
+ * the fcopy operation is aborted by hibernation, the daemon should remove the
116
+ * partially-copied file; to achieve this, the hv_utils driver always fakes a
117
+ * CANCEL_FCOPY message upon suspend, and later when the VM resumes back,
118
+ * the daemon calls hv_copy_cancel() to remove the file; if a file is copied
119
+ * successfully before suspend, hv_copy_finished() must reset target_fname to
120
+ * avoid that the file can be incorrectly removed upon resume, since the faked
121
+ * CANCEL_FCOPY message is spurious in this case.
122
+ */
120
123
 static int hv_copy_finished(void)
121
124
 {
122
125
 	close(target_fd);
126
+	target_fname[0] = '\0';
123
127
 	return 0;
124
128
 }
125
129
 static int hv_copy_cancel(void)
126
130
 {
127
131
 	close(target_fd);
128
-	unlink(target_fname);
132
+	if (strlen(target_fname) > 0) {
133
+		unlink(target_fname);
134
+		target_fname[0] = '\0';
135
+	}
129
136
 	return 0;
130
137
 
131
138
 }
..
..
@@ -140,7 +147,7 @@
140
147
 
141
148
 int main(int argc, char *argv[])
142
149
 {
143
-	int fcopy_fd;
150
+	int fcopy_fd = -1;
144
151
 	int error;
145
152
 	int daemonize = 1, long_index = 0, opt;
146
153
 	int version = FCOPY_CURRENT_VERSION;
..
..
@@ -150,7 +157,7 @@
150
157
 		struct hv_do_fcopy copy;
151
158
 		__u32 kernel_modver;
152
159
 	} buffer = { };
153
-	int in_handshake = 1;
160
+	int in_handshake;
154
161
 
155
162
 	static struct option long_options[] = {
156
163
 		{"help",	no_argument,	   0,  'h' },
..
..
@@ -179,6 +186,12 @@
179
186
 	openlog("HV_FCOPY", 0, LOG_USER);
180
187
 	syslog(LOG_INFO, "starting; pid is:%d", getpid());
181
188
 
189
+reopen_fcopy_fd:
190
+	if (fcopy_fd != -1)
191
+		close(fcopy_fd);
192
+	/* Remove any possible partially-copied file on error */
193
+	hv_copy_cancel();
194
+	in_handshake = 1;
182
195
 	fcopy_fd = open("/dev/vmbus/hv_fcopy", O_RDWR);
183
196
 
184
197
 	if (fcopy_fd < 0) {
..
..
@@ -205,7 +218,7 @@
205
218
 		len = pread(fcopy_fd, &buffer, sizeof(buffer), 0);
206
219
 		if (len < 0) {
207
220
 			syslog(LOG_ERR, "pread failed: %s", strerror(errno));
208
-			exit(EXIT_FAILURE);
221
+			goto reopen_fcopy_fd;
209
222
 		}
210
223
 
211
224
 		if (in_handshake) {
..
..
@@ -240,9 +253,14 @@
240
253
 
241
254
 		}
242
255
 
256
+		/*
257
+		 * pwrite() may return an error due to the faked CANCEL_FCOPY
258
+		 * message upon hibernation. Ignore the error by resetting the
259
+		 * dev file, i.e. closing and re-opening it.
260
+		 */
243
261
 		if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) {
244
262
 			syslog(LOG_ERR, "pwrite failed: %s", strerror(errno));
245
-			exit(EXIT_FAILURE);
263
+			goto reopen_fcopy_fd;
246
264
 		}
247
265
 	}
248
266
 }