Line data Source code
1 : // Copyright (c) 2009-2010 Satoshi Nakamoto
2 : // Copyright (c) 2009-2023 The Bitcoin Core developers
3 : // Distributed under the MIT software license, see the accompanying
4 : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 :
6 : #include <util/fs_helpers.h>
7 :
8 : #if defined(HAVE_CONFIG_H)
9 : #include <config/bitcoin-config.h>
10 : #endif
11 :
12 : #include <logging.h>
13 : #include <sync.h>
14 : #include <tinyformat.h>
15 : #include <util/fs.h>
16 : #include <util/getuniquepath.h>
17 : #include <util/syserror.h>
18 :
19 : #include <cerrno>
20 : #include <filesystem>
21 : #include <fstream>
22 : #include <map>
23 : #include <memory>
24 : #include <string>
25 : #include <system_error>
26 : #include <utility>
27 :
28 : #ifndef WIN32
29 : // for posix_fallocate, in configure.ac we check if it is present after this
30 : #ifdef __linux__
31 :
32 : #ifdef _POSIX_C_SOURCE
33 : #undef _POSIX_C_SOURCE
34 : #endif
35 :
36 : #define _POSIX_C_SOURCE 200112L
37 :
38 : #endif // __linux__
39 :
40 : #include <fcntl.h>
41 : #include <sys/resource.h>
42 : #include <unistd.h>
43 : #else
44 : #include <io.h> /* For _get_osfhandle, _chsize */
45 : #include <shlobj.h> /* For SHGetSpecialFolderPathW */
46 : #endif // WIN32
47 :
48 : /** Mutex to protect dir_locks. */
49 : static GlobalMutex cs_dir_locks;
50 : /** A map that contains all the currently held directory locks. After
51 : * successful locking, these will be held here until the global destructor
52 : * cleans them up and thus automatically unlocks them, or ReleaseDirectoryLocks
53 : * is called.
54 : */
55 2 : static std::map<std::string, std::unique_ptr<fsbridge::FileLock>> dir_locks GUARDED_BY(cs_dir_locks);
56 :
57 0 : bool LockDirectory(const fs::path& directory, const fs::path& lockfile_name, bool probe_only)
58 : {
59 0 : LOCK(cs_dir_locks);
60 0 : fs::path pathLockFile = directory / lockfile_name;
61 :
62 : // If a lock for this directory already exists in the map, don't try to re-lock it
63 0 : if (dir_locks.count(fs::PathToString(pathLockFile))) {
64 0 : return true;
65 : }
66 :
67 : // Create empty lock file if it doesn't exist.
68 0 : FILE* file = fsbridge::fopen(pathLockFile, "a");
69 0 : if (file) fclose(file);
70 0 : auto lock = std::make_unique<fsbridge::FileLock>(pathLockFile);
71 0 : if (!lock->TryLock()) {
72 0 : return error("Error while attempting to lock directory %s: %s", fs::PathToString(directory), lock->GetReason());
73 : }
74 2 : if (!probe_only) {
75 : // Lock successful and we're not just probing, put it into the map
76 0 : dir_locks.emplace(fs::PathToString(pathLockFile), std::move(lock));
77 0 : }
78 0 : return true;
79 0 : }
80 :
81 0 : void UnlockDirectory(const fs::path& directory, const fs::path& lockfile_name)
82 : {
83 0 : LOCK(cs_dir_locks);
84 0 : dir_locks.erase(fs::PathToString(directory / lockfile_name));
85 0 : }
86 :
87 0 : void ReleaseDirectoryLocks()
88 : {
89 0 : LOCK(cs_dir_locks);
90 0 : dir_locks.clear();
91 0 : }
92 :
93 0 : bool DirIsWritable(const fs::path& directory)
94 : {
95 0 : fs::path tmpFile = GetUniquePath(directory);
96 :
97 0 : FILE* file = fsbridge::fopen(tmpFile, "a");
98 0 : if (!file) return false;
99 :
100 0 : fclose(file);
101 0 : remove(tmpFile);
102 :
103 0 : return true;
104 0 : }
105 :
106 2 : bool CheckDiskSpace(const fs::path& dir, uint64_t additional_bytes)
107 : {
108 2 : constexpr uint64_t min_disk_space = 52428800; // 50 MiB
109 :
110 2 : uint64_t free_bytes_available = fs::space(dir).available;
111 2 : return free_bytes_available >= min_disk_space + additional_bytes;
112 : }
113 :
114 0 : std::streampos GetFileSize(const char* path, std::streamsize max)
115 : {
116 0 : std::ifstream file{path, std::ios::binary};
117 0 : file.ignore(max);
118 0 : return file.gcount();
119 0 : }
120 :
121 0 : bool FileCommit(FILE* file)
122 : {
123 0 : if (fflush(file) != 0) { // harmless if redundantly called
124 0 : LogPrintf("fflush failed: %s\n", SysErrorString(errno));
125 0 : return false;
126 : }
127 : #ifdef WIN32
128 : HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(file));
129 : if (FlushFileBuffers(hFile) == 0) {
130 : LogPrintf("FlushFileBuffers failed: %s\n", Win32ErrorString(GetLastError()));
131 : return false;
132 : }
133 : #elif defined(MAC_OSX) && defined(F_FULLFSYNC)
134 : if (fcntl(fileno(file), F_FULLFSYNC, 0) == -1) { // Manpage says "value other than -1" is returned on success
135 : LogPrintf("fcntl F_FULLFSYNC failed: %s\n", SysErrorString(errno));
136 : return false;
137 : }
138 : #elif HAVE_FDATASYNC
139 0 : if (fdatasync(fileno(file)) != 0 && errno != EINVAL) { // Ignore EINVAL for filesystems that don't support sync
140 0 : LogPrintf("fdatasync failed: %s\n", SysErrorString(errno));
141 0 : return false;
142 : }
143 : #else
144 : if (fsync(fileno(file)) != 0 && errno != EINVAL) {
145 : LogPrintf("fsync failed: %s\n", SysErrorString(errno));
146 : return false;
147 : }
148 : #endif
149 0 : return true;
150 0 : }
151 :
152 0 : void DirectoryCommit(const fs::path& dirname)
153 : {
154 : #ifndef WIN32
155 0 : FILE* file = fsbridge::fopen(dirname, "r");
156 0 : if (file) {
157 0 : fsync(fileno(file));
158 0 : fclose(file);
159 0 : }
160 : #endif
161 0 : }
162 :
163 0 : bool TruncateFile(FILE* file, unsigned int length)
164 : {
165 : #if defined(WIN32)
166 : return _chsize(_fileno(file), length) == 0;
167 : #else
168 0 : return ftruncate(fileno(file), length) == 0;
169 : #endif
170 : }
171 :
172 : /**
173 : * this function tries to raise the file descriptor limit to the requested number.
174 : * It returns the actual file descriptor limit (which may be more or less than nMinFD)
175 : */
176 1 : int RaiseFileDescriptorLimit(int nMinFD)
177 : {
178 : #if defined(WIN32)
179 : return 2048;
180 : #else
181 : struct rlimit limitFD;
182 1 : if (getrlimit(RLIMIT_NOFILE, &limitFD) != -1) {
183 1 : if (limitFD.rlim_cur < (rlim_t)nMinFD) {
184 0 : limitFD.rlim_cur = nMinFD;
185 0 : if (limitFD.rlim_cur > limitFD.rlim_max)
186 0 : limitFD.rlim_cur = limitFD.rlim_max;
187 0 : setrlimit(RLIMIT_NOFILE, &limitFD);
188 0 : getrlimit(RLIMIT_NOFILE, &limitFD);
189 0 : }
190 1 : return limitFD.rlim_cur;
191 : }
192 0 : return nMinFD; // getrlimit failed, assume it's fine
193 : #endif
194 1 : }
195 :
196 : /**
197 : * this function tries to make a particular range of a file allocated (corresponding to disk space)
198 : * it is advisory, and the range specified in the arguments will never contain live data
199 : */
200 2 : void AllocateFileRange(FILE* file, unsigned int offset, unsigned int length)
201 : {
202 : #if defined(WIN32)
203 : // Windows-specific version
204 : HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(file));
205 : LARGE_INTEGER nFileSize;
206 : int64_t nEndPos = (int64_t)offset + length;
207 : nFileSize.u.LowPart = nEndPos & 0xFFFFFFFF;
208 : nFileSize.u.HighPart = nEndPos >> 32;
209 : SetFilePointerEx(hFile, nFileSize, 0, FILE_BEGIN);
210 : SetEndOfFile(hFile);
211 : #elif defined(MAC_OSX)
212 : // OSX specific version
213 : // NOTE: Contrary to other OS versions, the OSX version assumes that
214 : // NOTE: offset is the size of the file.
215 : fstore_t fst;
216 : fst.fst_flags = F_ALLOCATECONTIG;
217 : fst.fst_posmode = F_PEOFPOSMODE;
218 : fst.fst_offset = 0;
219 : fst.fst_length = length; // mac os fst_length takes the # of free bytes to allocate, not desired file size
220 : fst.fst_bytesalloc = 0;
221 : if (fcntl(fileno(file), F_PREALLOCATE, &fst) == -1) {
222 : fst.fst_flags = F_ALLOCATEALL;
223 : fcntl(fileno(file), F_PREALLOCATE, &fst);
224 : }
225 : ftruncate(fileno(file), static_cast<off_t>(offset) + length);
226 : #else
227 : #if defined(HAVE_POSIX_FALLOCATE)
228 : // Version using posix_fallocate
229 2 : off_t nEndPos = (off_t)offset + length;
230 2 : if (0 == posix_fallocate(fileno(file), 0, nEndPos)) return;
231 : #endif
232 : // Fallback version
233 : // TODO: just write one byte per block
234 : static const char buf[65536] = {};
235 0 : if (fseek(file, offset, SEEK_SET)) {
236 0 : return;
237 : }
238 0 : while (length > 0) {
239 0 : unsigned int now = 65536;
240 0 : if (length < now)
241 0 : now = length;
242 0 : fwrite(buf, 1, now, file); // allowed to fail; this function is advisory anyway
243 0 : length -= now;
244 : }
245 : #endif
246 2 : }
247 :
248 : #ifdef WIN32
249 : fs::path GetSpecialFolderPath(int nFolder, bool fCreate)
250 : {
251 : WCHAR pszPath[MAX_PATH] = L"";
252 :
253 : if (SHGetSpecialFolderPathW(nullptr, pszPath, nFolder, fCreate)) {
254 : return fs::path(pszPath);
255 : }
256 :
257 : LogPrintf("SHGetSpecialFolderPathW() failed, could not obtain requested path.\n");
258 : return fs::path("");
259 : }
260 : #endif
261 :
262 0 : bool RenameOver(fs::path src, fs::path dest)
263 : {
264 : #ifdef __MINGW64__
265 : // This is a workaround for a bug in libstdc++ which
266 : // implements std::filesystem::rename with _wrename function.
267 : // This bug has been fixed in upstream:
268 : // - GCC 10.3: 8dd1c1085587c9f8a21bb5e588dfe1e8cdbba79e
269 : // - GCC 11.1: 1dfd95f0a0ca1d9e6cbc00e6cbfd1fa20a98f312
270 : // For more details see the commits mentioned above.
271 : return MoveFileExW(src.wstring().c_str(), dest.wstring().c_str(),
272 : MOVEFILE_REPLACE_EXISTING) != 0;
273 : #else
274 0 : std::error_code error;
275 0 : fs::rename(src, dest, error);
276 0 : return !error;
277 : #endif
278 : }
279 :
280 : /**
281 : * Ignores exceptions thrown by create_directories if the requested directory exists.
282 : * Specifically handles case where path p exists, but it wasn't possible for the user to
283 : * write to the parent directory.
284 : */
285 0 : bool TryCreateDirectories(const fs::path& p)
286 : {
287 : try {
288 0 : return fs::create_directories(p);
289 0 : } catch (const fs::filesystem_error&) {
290 0 : if (!fs::exists(p) || !fs::is_directory(p))
291 0 : throw;
292 0 : }
293 :
294 : // create_directories didn't create the directory, it had to have existed already
295 0 : return false;
296 0 : }
|
