1 /****************************************************************************
2 **
3 ** Copyright (C) 2016 The Qt Company Ltd.
4 ** Contact: https://www.qt.io/licensing/
5 **
6 ** This file is part of the QtCore module of the Qt Toolkit.
7 **
8 ** $QT_BEGIN_LICENSE:LGPL$
9 ** Commercial License Usage
10 ** Licensees holding valid commercial Qt licenses may use this file in
11 ** accordance with the commercial license agreement provided with the
12 ** Software or, alternatively, in accordance with the terms contained in
13 ** a written agreement between you and The Qt Company. For licensing terms
14 ** and conditions see https://www.qt.io/terms-conditions. For further
15 ** information use the contact form at https://www.qt.io/contact-us.
16 **
17 ** GNU Lesser General Public License Usage
18 ** Alternatively, this file may be used under the terms of the GNU Lesser
19 ** General Public License version 3 as published by the Free Software
20 ** Foundation and appearing in the file LICENSE.LGPL3 included in the
21 ** packaging of this file. Please review the following information to
22 ** ensure the GNU Lesser General Public License version 3 requirements
23 ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
24 **
25 ** GNU General Public License Usage
26 ** Alternatively, this file may be used under the terms of the GNU
27 ** General Public License version 2.0 or (at your option) the GNU General
28 ** Public license version 3 or any later version approved by the KDE Free
29 ** Qt Foundation. The licenses are as published by the Free Software
30 ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
31 ** included in the packaging of this file. Please review the following
32 ** information to ensure the GNU General Public License requirements will
33 ** be met: https://www.gnu.org/licenses/gpl-2.0.html and
34 ** https://www.gnu.org/licenses/gpl-3.0.html.
35 **
36 ** $QT_END_LICENSE$
37 **
38 ****************************************************************************/
39
40 #include "qfilesystemwatcher.h"
41 #include "qfilesystemwatcher_inotify_p.h"
42
43 #include "private/qcore_unix_p.h"
44 #include "private/qsystemerror_p.h"
45
46 #include <qdebug.h>
47 #include <qfile.h>
48 #include <qfileinfo.h>
49 #include <qscopeguard.h>
50 #include <qsocketnotifier.h>
51 #include <qvarlengtharray.h>
52
53 #if defined(Q_OS_LINUX)
54 #include <sys/syscall.h>
55 #include <sys/ioctl.h>
56 #include <unistd.h>
57 #include <fcntl.h>
58 #endif
59
60 #if defined(QT_NO_INOTIFY)
61
62 #if defined(Q_OS_QNX)
63 // These files should only be compiled on QNX if the inotify headers are found
64 #error "Should not get here."
65 #endif
66
67 #include <linux/types.h>
68
69 #if defined(__i386__)
70 # define __NR_inotify_init 291
71 # define __NR_inotify_add_watch 292
72 # define __NR_inotify_rm_watch 293
73 # define __NR_inotify_init1 332
74 #elif defined(__x86_64__)
75 # define __NR_inotify_init 253
76 # define __NR_inotify_add_watch 254
77 # define __NR_inotify_rm_watch 255
78 # define __NR_inotify_init1 294
79 #elif defined(__powerpc__) || defined(__powerpc64__)
80 # define __NR_inotify_init 275
81 # define __NR_inotify_add_watch 276
82 # define __NR_inotify_rm_watch 277
83 # define __NR_inotify_init1 318
84 #elif defined (__ia64__)
85 # define __NR_inotify_init 1277
86 # define __NR_inotify_add_watch 1278
87 # define __NR_inotify_rm_watch 1279
88 # define __NR_inotify_init1 1318
89 #elif defined (__s390__) || defined (__s390x__)
90 # define __NR_inotify_init 284
91 # define __NR_inotify_add_watch 285
92 # define __NR_inotify_rm_watch 286
93 # define __NR_inotify_init1 324
94 #elif defined (__alpha__)
95 # define __NR_inotify_init 444
96 # define __NR_inotify_add_watch 445
97 # define __NR_inotify_rm_watch 446
98 // no inotify_init1 for the Alpha
99 #elif defined (__sparc__) || defined (__sparc64__)
100 # define __NR_inotify_init 151
101 # define __NR_inotify_add_watch 152
102 # define __NR_inotify_rm_watch 156
103 # define __NR_inotify_init1 322
104 #elif defined (__arm__)
105 # define __NR_inotify_init 316
106 # define __NR_inotify_add_watch 317
107 # define __NR_inotify_rm_watch 318
108 # define __NR_inotify_init1 360
109 #elif defined (__sh__)
110 # define __NR_inotify_init 290
111 # define __NR_inotify_add_watch 291
112 # define __NR_inotify_rm_watch 292
113 # define __NR_inotify_init1 332
114 #elif defined (__sh64__)
115 # define __NR_inotify_init 318
116 # define __NR_inotify_add_watch 319
117 # define __NR_inotify_rm_watch 320
118 # define __NR_inotify_init1 360
119 #elif defined (__mips__)
120 # define __NR_inotify_init 284
121 # define __NR_inotify_add_watch 285
122 # define __NR_inotify_rm_watch 286
123 # define __NR_inotify_init1 329
124 #elif defined (__hppa__)
125 # define __NR_inotify_init 269
126 # define __NR_inotify_add_watch 270
127 # define __NR_inotify_rm_watch 271
128 # define __NR_inotify_init1 314
129 #elif defined (__avr32__)
130 # define __NR_inotify_init 240
131 # define __NR_inotify_add_watch 241
132 # define __NR_inotify_rm_watch 242
133 // no inotify_init1 for AVR32
134 #elif defined (__mc68000__)
135 # define __NR_inotify_init 284
136 # define __NR_inotify_add_watch 285
137 # define __NR_inotify_rm_watch 286
138 # define __NR_inotify_init1 328
139 #elif defined (__aarch64__)
140 # define __NR_inotify_init1 26
141 # define __NR_inotify_add_watch 27
142 # define __NR_inotify_rm_watch 28
143 // no inotify_init for aarch64
144 #else
145 # error "This architecture is not supported. Please see http://www.qt-project.org/"
146 #endif
147
148 #if !defined(IN_CLOEXEC) && defined(O_CLOEXEC) && defined(__NR_inotify_init1)
149 # define IN_CLOEXEC O_CLOEXEC
150 #endif
151
152 QT_BEGIN_NAMESPACE
153
154 #ifdef QT_LINUXBASE
155 // ### the LSB doesn't standardize syscall, need to wait until glib2.4 is standardized
syscall(...)156 static inline int syscall(...) { return -1; }
157 #endif
158
inotify_init()159 static inline int inotify_init()
160 {
161 #ifdef __NR_inotify_init
162 return syscall(__NR_inotify_init);
163 #else
164 return syscall(__NR_inotify_init1, 0);
165 #endif
166 }
167
inotify_add_watch(int fd,const char * name,__u32 mask)168 static inline int inotify_add_watch(int fd, const char *name, __u32 mask)
169 {
170 return syscall(__NR_inotify_add_watch, fd, name, mask);
171 }
172
inotify_rm_watch(int fd,__u32 wd)173 static inline int inotify_rm_watch(int fd, __u32 wd)
174 {
175 return syscall(__NR_inotify_rm_watch, fd, wd);
176 }
177
178 #ifdef IN_CLOEXEC
inotify_init1(int flags)179 static inline int inotify_init1(int flags)
180 {
181 return syscall(__NR_inotify_init1, flags);
182 }
183 #endif
184
185 // the following struct and values are documented in linux/inotify.h
186 extern "C" {
187
188 struct inotify_event {
189 __s32 wd;
190 __u32 mask;
191 __u32 cookie;
192 __u32 len;
193 char name[0];
194 };
195
196 #define IN_ACCESS 0x00000001
197 #define IN_MODIFY 0x00000002
198 #define IN_ATTRIB 0x00000004
199 #define IN_CLOSE_WRITE 0x00000008
200 #define IN_CLOSE_NOWRITE 0x00000010
201 #define IN_OPEN 0x00000020
202 #define IN_MOVED_FROM 0x00000040
203 #define IN_MOVED_TO 0x00000080
204 #define IN_CREATE 0x00000100
205 #define IN_DELETE 0x00000200
206 #define IN_DELETE_SELF 0x00000400
207 #define IN_MOVE_SELF 0x00000800
208 #define IN_UNMOUNT 0x00002000
209 #define IN_Q_OVERFLOW 0x00004000
210 #define IN_IGNORED 0x00008000
211
212 #define IN_CLOSE (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE)
213 #define IN_MOVE (IN_MOVED_FROM | IN_MOVED_TO)
214 }
215
216 QT_END_NAMESPACE
217
218 // --------- inotify.h end ----------
219
220 #else /* QT_NO_INOTIFY */
221
222 #include <sys/inotify.h>
223
224 // see https://github.com/android-ndk/ndk/issues/394
225 # if defined(Q_OS_ANDROID) && (__ANDROID_API__ < 21)
226 static inline int inotify_init1(int flags)
227 {
228 return syscall(__NR_inotify_init1, flags);
229 }
230 # endif
231
232 #endif
233
234 QT_BEGIN_NAMESPACE
235
create(QObject * parent)236 QInotifyFileSystemWatcherEngine *QInotifyFileSystemWatcherEngine::create(QObject *parent)
237 {
238 int fd = -1;
239 #if defined(IN_CLOEXEC)
240 fd = inotify_init1(IN_CLOEXEC);
241 #endif
242 if (fd == -1) {
243 fd = inotify_init();
244 if (fd == -1)
245 return nullptr;
246 }
247 return new QInotifyFileSystemWatcherEngine(fd, parent);
248 }
249
QInotifyFileSystemWatcherEngine(int fd,QObject * parent)250 QInotifyFileSystemWatcherEngine::QInotifyFileSystemWatcherEngine(int fd, QObject *parent)
251 : QFileSystemWatcherEngine(parent),
252 inotifyFd(fd),
253 notifier(fd, QSocketNotifier::Read, this)
254 {
255 fcntl(inotifyFd, F_SETFD, FD_CLOEXEC);
256 connect(¬ifier, SIGNAL(activated(QSocketDescriptor)), SLOT(readFromInotify()));
257 }
258
~QInotifyFileSystemWatcherEngine()259 QInotifyFileSystemWatcherEngine::~QInotifyFileSystemWatcherEngine()
260 {
261 notifier.setEnabled(false);
262 for (int id : qAsConst(pathToID))
263 inotify_rm_watch(inotifyFd, id < 0 ? -id : id);
264
265 ::close(inotifyFd);
266 }
267
addPaths(const QStringList & paths,QStringList * files,QStringList * directories)268 QStringList QInotifyFileSystemWatcherEngine::addPaths(const QStringList &paths,
269 QStringList *files,
270 QStringList *directories)
271 {
272 QStringList unhandled;
273 for (const QString &path : paths) {
274 QFileInfo fi(path);
275 bool isDir = fi.isDir();
276 auto sg = qScopeGuard([&]{ unhandled.push_back(path); });
277 if (isDir) {
278 if (directories->contains(path))
279 continue;
280 } else {
281 if (files->contains(path))
282 continue;
283 }
284
285 int wd = inotify_add_watch(inotifyFd,
286 QFile::encodeName(path),
287 (isDir
288 ? (0
289 | IN_ATTRIB
290 | IN_MOVE
291 | IN_CREATE
292 | IN_DELETE
293 | IN_DELETE_SELF
294 )
295 : (0
296 | IN_ATTRIB
297 | IN_MODIFY
298 | IN_MOVE
299 | IN_MOVE_SELF
300 | IN_DELETE_SELF
301 )));
302 if (wd < 0) {
303 if (errno != ENOENT)
304 qErrnoWarning("inotify_add_watch(%ls) failed:", path.constData());
305 continue;
306 }
307
308 sg.dismiss();
309
310 int id = isDir ? -wd : wd;
311 if (id < 0) {
312 directories->append(path);
313 } else {
314 files->append(path);
315 }
316
317 pathToID.insert(path, id);
318 idToPath.insert(id, path);
319 }
320
321 return unhandled;
322 }
323
removePaths(const QStringList & paths,QStringList * files,QStringList * directories)324 QStringList QInotifyFileSystemWatcherEngine::removePaths(const QStringList &paths,
325 QStringList *files,
326 QStringList *directories)
327 {
328 QStringList unhandled;
329 for (const QString &path : paths) {
330 int id = pathToID.take(path);
331
332 auto sg = qScopeGuard([&]{ unhandled.push_back(path); });
333
334 // Multiple paths could be associated to the same watch descriptor
335 // when a file is moved and added with the new name.
336 // So we should find and delete the correct one by using
337 // both id and path
338 auto path_range = idToPath.equal_range(id);
339 auto path_it = std::find(path_range.first, path_range.second, path);
340 if (path_it == idToPath.end())
341 continue;
342
343 const ssize_t num_elements = std::distance(path_range.first, path_range.second);
344 idToPath.erase(path_it);
345
346 // If there was only one path associated to the given id we should remove the watch
347 if (num_elements == 1) {
348 int wd = id < 0 ? -id : id;
349 inotify_rm_watch(inotifyFd, wd);
350 }
351
352 sg.dismiss();
353
354 if (id < 0) {
355 directories->removeAll(path);
356 } else {
357 files->removeAll(path);
358 }
359 }
360
361 return unhandled;
362 }
363
readFromInotify()364 void QInotifyFileSystemWatcherEngine::readFromInotify()
365 {
366 // qDebug("QInotifyFileSystemWatcherEngine::readFromInotify");
367
368 int buffSize = 0;
369 if (ioctl(inotifyFd, FIONREAD, (char *) &buffSize) == -1 || buffSize == 0)
370 return;
371
372 QVarLengthArray<char, 4096> buffer(buffSize);
373 buffSize = read(inotifyFd, buffer.data(), buffSize);
374 char *at = buffer.data();
375 char * const end = at + buffSize;
376
377 QHash<int, inotify_event *> eventForId;
378 while (at < end) {
379 inotify_event *event = reinterpret_cast<inotify_event *>(at);
380
381 if (eventForId.contains(event->wd))
382 eventForId[event->wd]->mask |= event->mask;
383 else
384 eventForId.insert(event->wd, event);
385
386 at += sizeof(inotify_event) + event->len;
387 }
388
389 QHash<int, inotify_event *>::const_iterator it = eventForId.constBegin();
390 while (it != eventForId.constEnd()) {
391 const inotify_event &event = **it;
392 ++it;
393
394 // qDebug() << "inotify event, wd" << event.wd << "mask" << Qt::hex << event.mask;
395
396 int id = event.wd;
397 QString path = getPathFromID(id);
398 if (path.isEmpty()) {
399 // perhaps a directory?
400 id = -id;
401 path = getPathFromID(id);
402 if (path.isEmpty())
403 continue;
404 }
405
406 // qDebug() << "event for path" << path;
407
408 if ((event.mask & (IN_DELETE_SELF | IN_MOVE_SELF | IN_UNMOUNT)) != 0) {
409 pathToID.remove(path);
410 idToPath.remove(id, getPathFromID(id));
411 if (!idToPath.contains(id))
412 inotify_rm_watch(inotifyFd, event.wd);
413
414 if (id < 0)
415 emit directoryChanged(path, true);
416 else
417 emit fileChanged(path, true);
418 } else {
419 if (id < 0)
420 emit directoryChanged(path, false);
421 else
422 emit fileChanged(path, false);
423 }
424 }
425 }
426
427 template <typename Hash, typename Key>
428 typename Hash::const_iterator
find_last_in_equal_range(const Hash & c,const Key & key)429 find_last_in_equal_range(const Hash &c, const Key &key)
430 {
431 // find c.equal_range(key).second - 1 without backwards iteration:
432 auto i = c.find(key);
433 const auto end = c.cend();
434 if (i == end)
435 return end;
436 decltype(i) prev;
437 do {
438 prev = i;
439 ++i;
440 } while (i != end && i.key() == key);
441 return prev;
442 }
443
getPathFromID(int id) const444 QString QInotifyFileSystemWatcherEngine::getPathFromID(int id) const
445 {
446 auto i = find_last_in_equal_range(idToPath, id);
447 return i == idToPath.cend() ? QString() : i.value() ;
448 }
449
450 QT_END_NAMESPACE
451
452 #include "moc_qfilesystemwatcher_inotify_p.cpp"
453