GCC Code Coverage Report

Directory: cvmfs/
File: cvmfs/nfs_maps_leveldb.cc
Date: 2025-02-09 02:34:19
Exec Total Coverage
Lines: 0 191 0.0%
Branches: 0 234 0.0%
Line Branch Exec Source
1 /**
2 * This file is part of the CernVM File System.
3 *
4 * The NFS maps module maintains inode -- path relations. An inode that is
5 * issued once by an NFS exported file system might be asked for
6 * any time later by clients.
7 *
8 * In "NFS mode", cvmfs will issue inodes consecutively and reuse inodes
9 * based on path name. The inode --> path and path --> inode maps are
10 * handled by leveldb. This workaround is comparable to the Fuse "noforget"
11 * option, except that the mappings are persistent and thus consistent during
12 * cvmfs restarts. Also, leveldb allows for restricting the memory consumption.
13 *
14 * The maps are not accounted for by the cache quota.
15 */
16
17 #include "nfs_maps_leveldb.h"
18
19 #include <unistd.h>
20
21 #include <cassert>
22 #include <cstddef>
23
24 #include "leveldb/cache.h"
25 #include "leveldb/db.h"
26 #include "leveldb/filter_policy.h"
27 #include "statistics.h"
28 #include "util/concurrency.h"
29 #include "util/exception.h"
30 #include "util/logging.h"
31 #include "util/pointer.h"
32 #include "util/posix.h"
33 #include "util/smalloc.h"
34
35 using namespace std; // NOLINT
36
37
38 ✗ NfsMapsLeveldb::ForkAwareEnv::ForkAwareEnv(NfsMapsLeveldb *maps)
39 : leveldb::EnvWrapper(leveldb::Env::Default())
40 ✗ , maps_(maps)
41 {
42 ✗ atomic_init32(&num_bg_threads_);
43 }
44
45
46 ✗ void NfsMapsLeveldb::ForkAwareEnv::StartThread(void (*f)(void*), void* a) {
47 ✗ if (maps_->spawned_) {
48 ✗ leveldb::Env::Default()->StartThread(f, a);
49 ✗ return;
50 }
51 ✗ PANIC(kLogDebug | kLogSyslogErr,
52 "single threaded leveldb::StartThread called");
53 // Unclear how to handle this because caller assumes that thread is started
54 }
55
56
57 ✗ void NfsMapsLeveldb::ForkAwareEnv::Schedule(void (*function)(void*), void* arg)
58 {
59 ✗ if (maps_->spawned_) {
60 ✗ leveldb::Env::Default()->Schedule(function, arg);
61 ✗ return;
62 }
63 ✗ LogCvmfs(kLogNfsMaps, kLogDebug,
64 "single threaded leveldb::Schedule called");
65 ✗ FuncArg *funcarg = new FuncArg();
66 ✗ funcarg->function = function;
67 ✗ funcarg->arg = arg;
68 ✗ funcarg->env = this;
69 ✗ atomic_inc32(&num_bg_threads_);
70 pthread_t bg_thread;
71 ✗ int retval = pthread_create(&bg_thread, NULL, MainFakeThread, funcarg);
72 ✗ assert(retval == 0);
73 ✗ retval = pthread_detach(bg_thread);
74 ✗ assert(retval == 0);
75 }
76
77
78 ✗ void NfsMapsLeveldb::ForkAwareEnv::WaitForBGThreads() {
79 ✗ while (atomic_read32(&num_bg_threads_) > 0)
80 ✗ SafeSleepMs(100);
81 }
82
83
84 /**
85 * Leveldb's usleep might collide with the ALARM timer
86 */
87 ✗ void NfsMapsLeveldb::ForkAwareEnv::SleepForMicroseconds(int micros) {
88 ✗ SafeSleepMs(micros/1000);
89 }
90
91
92 ✗ void *NfsMapsLeveldb::ForkAwareEnv::MainFakeThread(void *data) {
93 ✗ FuncArg *funcarg = reinterpret_cast<FuncArg *>(data);
94 ✗ funcarg->function(funcarg->arg);
95 ✗ atomic_dec32(&(funcarg->env->num_bg_threads_));
96 ✗ delete funcarg;
97 ✗ return NULL;
98 }
99
100
101 //------------------------------------------------------------------------------
102
103
104 ✗ NfsMapsLeveldb *NfsMapsLeveldb::Create(
105 const string &leveldb_dir,
106 const uint64_t root_inode,
107 const bool rebuild,
108 perf::Statistics *statistics)
109 {
110 ✗ assert(root_inode > 0);
111 ✗ UniquePtr<NfsMapsLeveldb> maps(new NfsMapsLeveldb());
112 ✗ maps->n_db_added_ = statistics->Register(
113 "nfs.leveldb.n_added", "total number of issued inode");
114
115 ✗ maps->root_inode_ = root_inode;
116 ✗ maps->fork_aware_env_ = new ForkAwareEnv(maps.weak_ref());
117 ✗ leveldb::Status status;
118 ✗ leveldb::Options leveldb_options;
119 ✗ leveldb_options.create_if_missing = true;
120 ✗ leveldb_options.env = maps->fork_aware_env_;
121
122 // Remove previous database traces
123 ✗ if (rebuild) {
124 ✗ LogCvmfs(kLogNfsMaps, kLogSyslogWarn,
125 "rebuilding NFS maps, might result in stale entries");
126 ✗ bool retval = RemoveTree(leveldb_dir + "/inode2path") &&
127 ✗ RemoveTree(leveldb_dir + "/path2inode");
128 ✗ if (!retval) {
129 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "failed to remove previous databases");
130 ✗ return NULL;
131 }
132 }
133
134 // Open databases
135 ✗ maps->cache_inode2path_ = leveldb::NewLRUCache(32 * 1024*1024);
136 ✗ leveldb_options.block_cache = maps->cache_inode2path_;
137 ✗ maps->filter_inode2path_ = leveldb::NewBloomFilterPolicy(10);
138 ✗ leveldb_options.filter_policy = maps->filter_inode2path_;
139 ✗ status = leveldb::DB::Open(leveldb_options, leveldb_dir + "/inode2path",
140 ✗ &maps->db_inode2path_);
141 ✗ if (!status.ok()) {
142 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "failed to create inode2path db: %s",
143 ✗ status.ToString().c_str());
144 ✗ return NULL;
145 }
146 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "inode2path opened");
147
148 // Hashes and inodes, no compression here
149 ✗ leveldb_options.compression = leveldb::kNoCompression;
150 // Random order, small block size to not trash caches
151 ✗ leveldb_options.block_size = 512;
152 ✗ maps->cache_path2inode_ = leveldb::NewLRUCache(8 * 1024*1024);
153 ✗ leveldb_options.block_cache = maps->cache_path2inode_;
154 ✗ maps->filter_path2inode_ = leveldb::NewBloomFilterPolicy(10);
155 ✗ leveldb_options.filter_policy = maps->filter_path2inode_;
156 ✗ status = leveldb::DB::Open(leveldb_options, leveldb_dir + "/path2inode",
157 ✗ &maps->db_path2inode_);
158 ✗ if (!status.ok()) {
159 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "failed to create path2inode db: %s",
160 ✗ status.ToString().c_str());
161 ✗ return NULL;
162 }
163 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "path2inode opened");
164
165 // Fetch highest issued inode
166 ✗ maps->seq_ = maps->FindInode(shash::Md5(shash::AsciiPtr("?seq")));
167 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "Sequence number is %" PRIu64, maps->seq_);
168 ✗ if (maps->seq_ == 0) {
169 ✗ maps->seq_ = maps->root_inode_;
170 // Insert root inode
171 ✗ PathString root_path;
172 ✗ maps->GetInode(root_path);
173 }
174
175 ✗ maps->fork_aware_env_->WaitForBGThreads();
176
177 ✗ return maps.Release();
178 }
179
180 ✗ void NfsMapsLeveldb::SetInodeResidue(unsigned residue_class, unsigned remainder)
181 {
182 ✗ MutexLockGuard lock_guard(lock_);
183 ✗ if (residue_class < 2) {
184 ✗ inode_residue_class_ = 1;
185 ✗ inode_remainder_ = 0;
186 } else {
187 ✗ inode_residue_class_ = residue_class;
188 ✗ inode_remainder_ = remainder % residue_class;
189 ✗ seq_ = ((seq_ / inode_residue_class_) + 1)
190 ✗ * inode_residue_class_ + inode_remainder_;
191 }
192 }
193
194
195 ✗ uint64_t NfsMapsLeveldb::FindInode(const shash::Md5 &path) {
196 ✗ leveldb::Status status;
197 ✗ leveldb::Slice key(reinterpret_cast<const char *>(path.digest),
198 ✗ path.GetDigestSize());
199 ✗ string result;
200
201 ✗ status = db_path2inode_->Get(leveldb::ReadOptions(), key, &result);
202 ✗ if (!status.ok() && !status.IsNotFound()) {
203 ✗ PANIC(kLogSyslogErr, "failed to read from path2inode db (path %s): %s",
204 path.ToString().c_str(), status.ToString().c_str());
205 }
206
207 ✗ if (status.IsNotFound()) {
208 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "path %s not found",
209 ✗ path.ToString().c_str());
210 ✗ return 0;
211 } else {
212 ✗ const uint64_t *inode = reinterpret_cast<const uint64_t *>(result.data());
213 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "path %s maps to inode %" PRIu64,
214 ✗ path.ToString().c_str(), *inode);
215 ✗ return *inode;
216 }
217 }
218
219
220 ✗ uint64_t NfsMapsLeveldb::GetInode(const PathString &path) {
221 ✗ const shash::Md5 md5_path(path.GetChars(), path.GetLength());
222 ✗ uint64_t inode = FindInode(md5_path);
223 ✗ if (inode != 0)
224 ✗ return inode;
225
226 ✗ MutexLockGuard m(lock_);
227 // Search again to avoid race
228 ✗ inode = FindInode(md5_path);
229 ✗ if (inode != 0) {
230 ✗ return inode;
231 }
232
233 // Issue new inode
234 ✗ inode = seq_;
235 ✗ seq_ += inode_residue_class_;
236 ✗ PutPath2Inode(md5_path, inode);
237 ✗ PutInode2Path(inode, path);
238 ✗ perf::Inc(n_db_added_);
239 ✗ return inode;
240 }
241
242
243 /**
244 * Finds the path that belongs to an inode. This must be successful. The
245 * inode input comes from the file system, i.e. it must have been issued
246 * before.
247 * \return false if not found
248 */
249 ✗ bool NfsMapsLeveldb::GetPath(const uint64_t inode, PathString *path) {
250 ✗ leveldb::Status status;
251 ✗ leveldb::Slice key(reinterpret_cast<const char *>(&inode), sizeof(inode));
252 ✗ string result;
253
254 ✗ status = db_inode2path_->Get(leveldb::ReadOptions(), key, &result);
255 ✗ if (status.IsNotFound()) {
256 ✗ LogCvmfs(kLogNfsMaps, kLogDebug,
257 "failed to find inode %" PRIu64 " in NFS maps, returning ESTALE",
258 inode);
259 ✗ return false;
260 }
261 ✗ if (!status.ok()) {
262 ✗ PANIC(kLogSyslogErr,
263 "failed to read from inode2path db inode %" PRIu64 ": %s", inode,
264 status.ToString().c_str());
265 }
266
267 ✗ path->Assign(result.data(), result.length());
268 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "inode %" PRIu64 " maps to path %s",
269 inode, path->c_str());
270 ✗ return true;
271 }
272
273
274 ✗ string NfsMapsLeveldb::GetStatistics() {
275 ✗ string stats;
276
277 ✗ db_inode2path_->GetProperty(leveldb::Slice("leveldb.stats"), &stats);
278 ✗ stats += "inode --> path database:\n" + stats + "\n";
279
280 ✗ db_path2inode_->GetProperty(leveldb::Slice("leveldb.stats"), &stats);
281 ✗ stats += "path --> inode database:\n" + stats + "\n";
282
283 ✗ return stats;
284 }
285
286
287 ✗ NfsMapsLeveldb::NfsMapsLeveldb()
288 ✗ : db_inode2path_(NULL)
289 ✗ , db_path2inode_(NULL)
290 ✗ , cache_inode2path_(NULL)
291 ✗ , cache_path2inode_(NULL)
292 ✗ , filter_inode2path_(NULL)
293 ✗ , filter_path2inode_(NULL)
294 ✗ , fork_aware_env_(NULL)
295 ✗ , root_inode_(0)
296 ✗ , seq_(0)
297 ✗ , lock_(NULL)
298 ✗ , spawned_(false)
299 ✗ , inode_residue_class_(1)
300 ✗ , inode_remainder_(0)
301 ✗ , n_db_added_(NULL)
302 {
303 ✗ lock_ = reinterpret_cast<pthread_mutex_t *>(smalloc(sizeof(pthread_mutex_t)));
304 ✗ int retval = pthread_mutex_init(lock_, NULL);
305 ✗ assert(retval == 0);
306 }
307
308
309 ✗ NfsMapsLeveldb::~NfsMapsLeveldb() {
310 ✗ PutPath2Inode(shash::Md5(shash::AsciiPtr("?seq")), seq_);
311
312 ✗ delete db_path2inode_;
313 ✗ delete cache_path2inode_;
314 ✗ delete filter_path2inode_;
315 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "path2inode closed");
316 ✗ delete db_inode2path_;
317 ✗ delete cache_inode2path_;
318 ✗ delete filter_inode2path_;
319 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "inode2path closed");
320 ✗ delete fork_aware_env_;
321 ✗ pthread_mutex_destroy(lock_);
322 ✗ free(lock_);
323 }
324
325
326 ✗ void NfsMapsLeveldb::PutInode2Path(
327 const uint64_t inode,
328 const PathString &path)
329 {
330 ✗ leveldb::Status status;
331 ✗ leveldb::Slice key(reinterpret_cast<const char *>(&inode), sizeof(inode));
332 ✗ leveldb::Slice value(path.GetChars(), path.GetLength());
333
334 ✗ status = db_inode2path_->Put(leveldb::WriteOptions(), key, value);
335 ✗ if (!status.ok()) {
336 ✗ PANIC(kLogSyslogErr,
337 "failed to write inode2path entry (%" PRIu64 " --> %s): %s", inode,
338 path.c_str(), status.ToString().c_str());
339 }
340 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "stored inode %" PRIu64 " --> path %s",
341 inode, path.c_str());
342 }
343
344
345 ✗ void NfsMapsLeveldb::PutPath2Inode(
346 const shash::Md5 &path,
347 const uint64_t inode)
348 {
349 ✗ leveldb::Status status;
350 ✗ leveldb::Slice key(reinterpret_cast<const char *>(path.digest),
351 ✗ path.GetDigestSize());
352 ✗ leveldb::Slice value(reinterpret_cast<const char *>(&inode), sizeof(inode));
353
354 ✗ status = db_path2inode_->Put(leveldb::WriteOptions(), key, value);
355 ✗ if (!status.ok()) {
356 ✗ PANIC(kLogSyslogErr,
357 "failed to write path2inode entry (%s --> %" PRIu64 "): %s",
358 path.ToString().c_str(), inode, status.ToString().c_str());
359 }
360 ✗ LogCvmfs(kLogNfsMaps, kLogDebug, "stored path %s --> inode %" PRIu64,
361 ✗ path.ToString().c_str(), inode);
362 }
363