1 /*
2 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 #include "jni.h"
27 #include "jni_util.h"
28 #include "jvm.h"
29 #include "jlong.h"
30 #include "sun_nio_ch_FileDispatcherImpl.h"
31 #include "java_lang_Long.h"
32 #include <sys/types.h>
33 #include <sys/socket.h>
34 #include <fcntl.h>
35 #include <sys/uio.h>
36 #include <unistd.h>
37 #if defined(__linux__)
38 #include <linux/fs.h>
39 #include <sys/ioctl.h>
40 #endif
41 #include "nio.h"
42 #include "nio_util.h"
43
44 #ifdef _ALLBSD_SOURCE
45 #define stat64 stat
46 #define flock64 flock
47 #define off64_t off_t
48 #define F_SETLKW64 F_SETLKW
49 #define F_SETLK64 F_SETLK
50
51 #define pread64 pread
52 #define pwrite64 pwrite
53 #define ftruncate64 ftruncate
54 #define fstat64 fstat
55
56 #define fdatasync fsync
57 #endif
58
59 static int preCloseFD = -1; /* File descriptor to which we dup other fd's
60 before closing them for real */
61
62
63 JNIEXPORT void JNICALL
64 Java_sun_nio_ch_FileDispatcherImpl_init(JNIEnv *env, jclass cl)
65 {
66 int sp[2];
67 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sp) < 0) {
68 JNU_ThrowIOExceptionWithLastError(env, "socketpair failed");
69 return;
70 }
71 preCloseFD = sp[0];
72 close(sp[1]);
73 }
74
75 JNIEXPORT jint JNICALL
76 Java_sun_nio_ch_FileDispatcherImpl_read0(JNIEnv *env, jclass clazz,
77 jobject fdo, jlong address, jint len)
78 {
79 jint fd = fdval(env, fdo);
80 void *buf = (void *)jlong_to_ptr(address);
81
82 return convertReturnVal(env, read(fd, buf, len), JNI_TRUE);
83 }
84
85 JNIEXPORT jint JNICALL
86 Java_sun_nio_ch_FileDispatcherImpl_pread0(JNIEnv *env, jclass clazz, jobject fdo,
87 jlong address, jint len, jlong offset)
88 {
89 jint fd = fdval(env, fdo);
90 void *buf = (void *)jlong_to_ptr(address);
91
92 return convertReturnVal(env, pread64(fd, buf, len, offset), JNI_TRUE);
93 }
94
95 JNIEXPORT jlong JNICALL
96 Java_sun_nio_ch_FileDispatcherImpl_readv0(JNIEnv *env, jclass clazz,
97 jobject fdo, jlong address, jint len)
98 {
99 jint fd = fdval(env, fdo);
100 struct iovec *iov = (struct iovec *)jlong_to_ptr(address);
101 return convertLongReturnVal(env, readv(fd, iov, len), JNI_TRUE);
102 }
103
104 JNIEXPORT jint JNICALL
105 Java_sun_nio_ch_FileDispatcherImpl_write0(JNIEnv *env, jclass clazz,
106 jobject fdo, jlong address, jint len)
107 {
108 jint fd = fdval(env, fdo);
109 void *buf = (void *)jlong_to_ptr(address);
110
111 return convertReturnVal(env, write(fd, buf, len), JNI_FALSE);
112 }
113
114 JNIEXPORT jint JNICALL
115 Java_sun_nio_ch_FileDispatcherImpl_pwrite0(JNIEnv *env, jclass clazz, jobject fdo,
116 jlong address, jint len, jlong offset)
117 {
118 jint fd = fdval(env, fdo);
119 void *buf = (void *)jlong_to_ptr(address);
120
121 return convertReturnVal(env, pwrite64(fd, buf, len, offset), JNI_FALSE);
122 }
123
124 JNIEXPORT jlong JNICALL
125 Java_sun_nio_ch_FileDispatcherImpl_writev0(JNIEnv *env, jclass clazz,
126 jobject fdo, jlong address, jint len)
127 {
128 jint fd = fdval(env, fdo);
129 struct iovec *iov = (struct iovec *)jlong_to_ptr(address);
130 return convertLongReturnVal(env, writev(fd, iov, len), JNI_FALSE);
131 }
132
133 static jlong
134 handle(JNIEnv *env, jlong rv, char *msg)
135 {
136 if (rv >= 0)
137 return rv;
138 if (errno == EINTR)
139 return IOS_INTERRUPTED;
140 JNU_ThrowIOExceptionWithLastError(env, msg);
141 return IOS_THROWN;
142 }
143
144 JNIEXPORT jint JNICALL
145 Java_sun_nio_ch_FileDispatcherImpl_force0(JNIEnv *env, jobject this,
146 jobject fdo, jboolean md)
147 {
148 jint fd = fdval(env, fdo);
149 int result = 0;
150
151 #ifdef MACOSX
152 result = fcntl(fd, F_FULLFSYNC);
153 if (result == -1 && errno == ENOTSUP) {
154 /* Try fsync() in case F_FULLSYUNC is not implemented on the file system. */
155 result = fsync(fd);
156 }
157 #else /* end MACOSX, begin not-MACOSX */
158 if (md == JNI_FALSE) {
159 result = fdatasync(fd);
160 } else {
161 #ifdef _AIX
162 /* On AIX, calling fsync on a file descriptor that is opened only for
163 * reading results in an error ("EBADF: The FileDescriptor parameter is
164 * not a valid file descriptor open for writing.").
165 * However, at this point it is not possibly anymore to read the
166 * 'writable' attribute of the corresponding file channel so we have to
167 * use 'fcntl'.
168 */
169 int getfl = fcntl(fd, F_GETFL);
170 if (getfl >= 0 && (getfl & O_ACCMODE) == O_RDONLY) {
171 return 0;
172 }
173 #endif /* _AIX */
174 result = fsync(fd);
175 }
176 #endif /* not-MACOSX */
177 return handle(env, result, "Force failed");
178 }
179
180 JNIEXPORT jint JNICALL
181 Java_sun_nio_ch_FileDispatcherImpl_truncate0(JNIEnv *env, jobject this,
182 jobject fdo, jlong size)
183 {
184 return handle(env,
185 ftruncate64(fdval(env, fdo), size),
186 "Truncation failed");
187 }
188
189 JNIEXPORT jint JNICALL
190 Java_sun_nio_ch_FileDispatcherImpl_allocate0(JNIEnv *env, jobject this,
191 jobject fdo, jlong size)
192 {
193 #if defined(__linux__)
194 /*
195 * On Linux, if the file size is being increased, then ftruncate64()
196 * will modify the metadata value of the size without actually allocating
197 * any blocks which can cause a SIGBUS error if the file is subsequently
198 * memory-mapped.
199 */
200 // Return on success or if errno is neither EOPNOTSUPP nor ENOSYS
201 int result = fallocate64(fdval(env, fdo), 0, 0, size);
202 if (result == 0) {
203 return 0;
204 } else if (errno != EOPNOTSUPP && errno != ENOSYS) {
205 return handle(env, result, "Allocation failed");
206 }
207 #endif
208 return handle(env,
209 ftruncate64(fdval(env, fdo), size),
210 "Truncation failed");
211 }
212
213 JNIEXPORT jlong JNICALL
214 Java_sun_nio_ch_FileDispatcherImpl_size0(JNIEnv *env, jobject this, jobject fdo)
215 {
216 jint fd = fdval(env, fdo);
217 struct stat64 fbuf;
218
219 if (fstat64(fd, &fbuf) < 0)
220 return handle(env, -1, "Size failed");
221
222 #ifdef BLKGETSIZE64
223 if (S_ISBLK(fbuf.st_mode)) {
224 uint64_t size;
225 if (ioctl(fd, BLKGETSIZE64, &size) < 0)
226 return handle(env, -1, "Size failed");
227 return (jlong)size;
228 }
229 #endif
230
231 return fbuf.st_size;
232 }
233
234 JNIEXPORT jint JNICALL
235 Java_sun_nio_ch_FileDispatcherImpl_lock0(JNIEnv *env, jobject this, jobject fdo,
236 jboolean block, jlong pos, jlong size,
237 jboolean shared)
238 {
239 jint fd = fdval(env, fdo);
240 jint lockResult = 0;
241 int cmd = 0;
242 struct flock64 fl;
243
244 fl.l_whence = SEEK_SET;
245 if (size == (jlong)java_lang_Long_MAX_VALUE) {
246 fl.l_len = (off64_t)0;
247 } else {
248 fl.l_len = (off64_t)size;
249 }
250 fl.l_start = (off64_t)pos;
251 if (shared == JNI_TRUE) {
252 fl.l_type = F_RDLCK;
253 } else {
254 fl.l_type = F_WRLCK;
255 }
256 if (block == JNI_TRUE) {
257 cmd = F_SETLKW64;
258 } else {
259 cmd = F_SETLK64;
260 }
261 lockResult = fcntl(fd, cmd, &fl);
262 if (lockResult < 0) {
263 if ((cmd == F_SETLK64) && (errno == EAGAIN || errno == EACCES))
264 return sun_nio_ch_FileDispatcherImpl_NO_LOCK;
265 if (errno == EINTR)
266 return sun_nio_ch_FileDispatcherImpl_INTERRUPTED;
267 JNU_ThrowIOExceptionWithLastError(env, "Lock failed");
268 }
269 return 0;
270 }
271
272 JNIEXPORT void JNICALL
273 Java_sun_nio_ch_FileDispatcherImpl_release0(JNIEnv *env, jobject this,
274 jobject fdo, jlong pos, jlong size)
275 {
276 jint fd = fdval(env, fdo);
277 jint lockResult = 0;
278 struct flock64 fl;
279 int cmd = F_SETLK64;
280
281 fl.l_whence = SEEK_SET;
282 if (size == (jlong)java_lang_Long_MAX_VALUE) {
283 fl.l_len = (off64_t)0;
284 } else {
285 fl.l_len = (off64_t)size;
286 }
287 fl.l_start = (off64_t)pos;
288 fl.l_type = F_UNLCK;
289 lockResult = fcntl(fd, cmd, &fl);
290 if (lockResult < 0) {
291 JNU_ThrowIOExceptionWithLastError(env, "Release failed");
292 }
293 }
294
295
296 static void closeFileDescriptor(JNIEnv *env, int fd) {
297 if (fd != -1) {
298 int result = close(fd);
299 if (result < 0)
300 JNU_ThrowIOExceptionWithLastError(env, "Close failed");
301 }
302 }
303
304 JNIEXPORT void JNICALL
305 Java_sun_nio_ch_FileDispatcherImpl_close0(JNIEnv *env, jclass clazz, jobject fdo)
306 {
307 jint fd = fdval(env, fdo);
308 closeFileDescriptor(env, fd);
309 }
310
311 JNIEXPORT void JNICALL
312 Java_sun_nio_ch_FileDispatcherImpl_preClose0(JNIEnv *env, jclass clazz, jobject fdo)
313 {
314 jint fd = fdval(env, fdo);
315 if (preCloseFD >= 0) {
316 if (dup2(preCloseFD, fd) < 0)
317 JNU_ThrowIOExceptionWithLastError(env, "dup2 failed");
318 }
319 }
320
321 JNIEXPORT void JNICALL
322 Java_sun_nio_ch_FileDispatcherImpl_closeIntFD(JNIEnv *env, jclass clazz, jint fd)
323 {
324 closeFileDescriptor(env, fd);
325 }