GCC Code Coverage Report

Directory: cvmfs/
File: cvmfs/fuse_remount.cc
Date: 2025-10-26 02:35:25
Exec Total Coverage
Lines: 0 199 0.0%
Branches: 0 212 0.0%
Line Branch Exec Source
1 /**
2 * This file is part of the CernVM File System.
3 */
4
5
6 #include "fuse_remount.h"
7
8 #include <errno.h>
9 #include <poll.h>
10 #include <unistd.h>
11
12 #include <cassert>
13 #include <cstdlib>
14 #include <cstring>
15
16 #include "backoff.h"
17 #include "catalog_mgr_client.h"
18 #include "fuse_inode_gen.h"
19 #include "lru_md.h"
20 #include "mountpoint.h"
21 #include "statistics.h"
22 #include "util/exception.h"
23 #include "util/logging.h"
24 #include "util/platform.h"
25 #include "util/posix.h"
26
27 using namespace std; // NOLINT
28
29
30 ✗ FuseRemounter::Status FuseRemounter::ChangeRoot(const shash::Any &root_hash) {
31 ✗ if (mountpoint_->catalog_mgr()->GetRootHash() == root_hash)
32 ✗ return kStatusUp2Date;
33
34 ✗ const FenceGuard fence_guard(&fence_maintenance_);
35 ✗ if (IsInMaintenanceMode())
36 ✗ return kStatusMaintenance;
37
38 ✗ if (atomic_cas32(&drainout_mode_, 0, 1)) {
39 // As of this point, fuse callbacks return zero as cache timeout
40 ✗ LogCvmfs(kLogCvmfs, kLogDebug, "chroot, draining out meta-data caches");
41 ✗ invalidator_handle_.Reset();
42 ✗ invalidator_->InvalidateInodes(&invalidator_handle_);
43 ✗ atomic_inc32(&drainout_mode_);
44 // drainout_mode_ == 2, IsInDrainoutMode is now 'true'
45 } else {
46 ✗ LogCvmfs(kLogCvmfs, kLogDebug, "already in drainout mode, leaving");
47 ✗ return kStatusDraining;
48 }
49
50 ✗ int32_t drainout_code = 0;
51 ✗ BackoffThrottle throttle;
52 do {
53 ✗ TryFinish(root_hash);
54 ✗ drainout_code = atomic_read32(&drainout_mode_);
55 ✗ if (drainout_code == 0)
56 ✗ break;
57 ✗ throttle.Throttle();
58 } while (true);
59
60 ✗ if (mountpoint_->catalog_mgr()->GetRootHash() == root_hash)
61 ✗ return kStatusUp2Date;
62 ✗ return kStatusFailGeneral;
63 }
64
65
66 /**
67 * Executed by the trigger thread, or triggered from cvmfs_talk. Moves into
68 * drainout mode if a new catalog is available online.
69 */
70 ✗ FuseRemounter::Status FuseRemounter::Check() {
71 ✗ const FenceGuard fence_guard(&fence_maintenance_);
72 ✗ if (IsInMaintenanceMode())
73 ✗ return kStatusMaintenance;
74
75 ✗ LogCvmfs(kLogCvmfs, kLogDebug,
76 "catalog TTL expired, checking revision against blacklists");
77 ✗ if (mountpoint_->ReloadBlacklists()
78 ✗ && mountpoint_->catalog_mgr()->IsRevisionBlacklisted()) {
79 ✗ PANIC(kLogDebug | kLogSyslogErr,
80 "repository revision blacklisted, aborting");
81 }
82
83 ✗ LogCvmfs(kLogCvmfs, kLogDebug, "remounting root catalog");
84 ✗ const catalog::LoadReturn retval = mountpoint_->catalog_mgr()
85 ✗ ->RemountDryrun();
86 ✗ switch (retval) {
87 ✗ case catalog::kLoadNew:
88 ✗ SetOfflineMode(false);
89 ✗ if (atomic_cas32(&drainout_mode_, 0, 1)) {
90 // As of this point, fuse callbacks return zero as cache timeout
91 ✗ LogCvmfs(kLogCvmfs, kLogDebug,
92 "new catalog revision available, "
93 "draining out meta-data caches");
94 ✗ invalidator_handle_.Reset();
95 ✗ invalidator_->InvalidateInodes(&invalidator_handle_);
96 ✗ atomic_inc32(&drainout_mode_);
97 // drainout_mode_ == 2, IsInDrainoutMode is now 'true'
98 } else {
99 ✗ LogCvmfs(kLogCvmfs, kLogDebug, "already in drainout mode, leaving");
100 }
101 ✗ return kStatusDraining;
102 ✗ case catalog::kLoadFail:
103 case catalog::kLoadNoSpace:
104 ✗ LogCvmfs(kLogCvmfs, kLogDebug,
105 "reload failed (%s), applying short term TTL",
106 catalog::Code2Ascii(retval));
107 ✗ SetOfflineMode(true);
108 ✗ catalogs_valid_until_ = time(NULL) + MountPoint::kShortTermTTL;
109 ✗ SetAlarm(MountPoint::kShortTermTTL);
110 ✗ return (retval == catalog::kLoadFail) ? kStatusFailGeneral
111 ✗ : kStatusFailNoSpace;
112 ✗ case catalog::kLoadUp2Date: {
113 ✗ LogCvmfs(kLogCvmfs, kLogDebug,
114 "catalog up to date (could be offline mode)");
115 ✗ SetOfflineMode(mountpoint_->catalog_mgr()->offline_mode());
116 ✗ const unsigned ttl = offline_mode_ ? MountPoint::kShortTermTTL
117 ✗ : mountpoint_->GetEffectiveTtlSec();
118 ✗ catalogs_valid_until_ = time(NULL) + ttl;
119 ✗ SetAlarm(ttl);
120 ✗ return kStatusUp2Date;
121 }
122 ✗ default:
123 ✗ PANIC(NULL);
124 }
125 }
126
127
128 /**
129 * Used from the TalkManager. Continuously calls 'check' until it returns with
130 * "up to date" or a failure.
131 */
132 ✗ FuseRemounter::Status FuseRemounter::CheckSynchronously() {
133 ✗ BackoffThrottle throttle;
134 while (true) {
135 ✗ const Status status = Check();
136 ✗ switch (status) {
137 ✗ case kStatusDraining:
138 ✗ TryFinish();
139 ✗ break;
140 ✗ default:
141 ✗ return status;
142 }
143 ✗ throttle.Throttle();
144 }
145 }
146
147
148 ✗ void FuseRemounter::EnterMaintenanceMode() {
149 ✗ fence_maintenance_.Drain();
150 ✗ atomic_cas32(&maintenance_mode_, 0, 1);
151 ✗ fence_maintenance_.Open();
152
153 // All running Check() and TryFinish() methods returned. Both methods now
154 // return immediately as noops.
155
156 // Flush caches before reload of fuse module
157 ✗ invalidator_handle_.Reset();
158 ✗ invalidator_->InvalidateInodes(&invalidator_handle_);
159 ✗ invalidator_handle_.WaitFor();
160 }
161
162 ✗ FuseRemounter::FuseRemounter(MountPoint *mountpoint,
163 cvmfs::InodeGenerationInfo *inode_generation_info,
164 void **fuse_channel_or_session,
165 ✗ bool fuse_notify_invalidation)
166 ✗ : mountpoint_(mountpoint)
167 ✗ , inode_generation_info_(inode_generation_info)
168 ✗ , invalidator_(new FuseInvalidator(mountpoint, fuse_channel_or_session,
169 ✗ fuse_notify_invalidation))
170 ✗ , invalidator_handle_(static_cast<int>(mountpoint->kcache_timeout_sec()))
171 ✗ , fence_(new Fence())
172 ✗ , offline_mode_(false)
173 ✗ , catalogs_valid_until_(MountPoint::kIndefiniteDeadline) {
174 ✗ memset(&thread_remount_trigger_, 0, sizeof(thread_remount_trigger_));
175 ✗ pipe_remount_trigger_[0] = pipe_remount_trigger_[1] = -1;
176 ✗ atomic_init32(&drainout_mode_);
177 ✗ atomic_init32(&maintenance_mode_);
178 ✗ atomic_init32(&critical_section_);
179 }
180
181 ✗ FuseRemounter::~FuseRemounter() {
182 ✗ if (HasRemountTrigger()) {
183 ✗ char quit = 'Q';
184 ✗ WritePipe(pipe_remount_trigger_[1], &quit, 1);
185 ✗ pthread_join(thread_remount_trigger_, NULL);
186 ✗ ClosePipe(pipe_remount_trigger_);
187 }
188 ✗ delete invalidator_;
189 ✗ delete fence_;
190 }
191
192
193 /**
194 * Triggers the Check() method when the catalog TTL expires. Works essentially
195 * as an alarm() timer.
196 */
197 ✗ void *FuseRemounter::MainRemountTrigger(void *data) {
198 ✗ FuseRemounter *remounter = reinterpret_cast<FuseRemounter *>(data);
199 ✗ LogCvmfs(kLogCvmfs, kLogDebug, "starting remount trigger");
200 char c;
201 ✗ int timeout_ms = -1;
202 ✗ uint64_t deadline = 0;
203 struct pollfd watch_ctrl;
204 ✗ watch_ctrl.fd = remounter->pipe_remount_trigger_[0];
205 ✗ watch_ctrl.events = POLLIN | POLLPRI;
206 while (true) {
207 ✗ watch_ctrl.revents = 0;
208 ✗ const int retval = poll(&watch_ctrl, 1, timeout_ms);
209 ✗ if (retval < 0) {
210 ✗ if (errno == EINTR) {
211 ✗ if (timeout_ms >= 0) {
212 ✗ const uint64_t now = platform_monotonic_time();
213 ✗ timeout_ms = (now > deadline) ? 0 : (deadline - now) * 1000;
214 }
215 ✗ continue;
216 }
217 ✗ PANIC(kLogSyslogErr | kLogDebug,
218 "remount trigger connection failure (%d)", errno);
219 }
220
221 ✗ if (retval == 0) {
222 ✗ remounter->Check();
223 ✗ timeout_ms = -1;
224 ✗ continue;
225 }
226
227 ✗ assert(watch_ctrl.revents != 0);
228
229 ✗ ReadPipe(remounter->pipe_remount_trigger_[0], &c, 1);
230 ✗ if (c == 'Q')
231 ✗ break;
232 ✗ assert(c == 'T');
233 ✗ ReadPipe(remounter->pipe_remount_trigger_[0], &timeout_ms, sizeof(int));
234 ✗ deadline = platform_monotonic_time() + timeout_ms / 1000;
235 }
236 ✗ LogCvmfs(kLogCvmfs, kLogDebug, "stopping remount trigger");
237 ✗ return NULL;
238 }
239
240
241 ✗ void FuseRemounter::SetAlarm(int timeout) {
242 // Remounting could be called for a non auto-update repository
243 ✗ if (!HasRemountTrigger())
244 ✗ return;
245
246 ✗ timeout *= 1000; // timeout given in ms
247 ✗ const unsigned buf_size = 1 + sizeof(int);
248 char buf[buf_size];
249 ✗ buf[0] = 'T';
250 ✗ memcpy(&buf[1], &timeout, sizeof(timeout));
251 ✗ WritePipe(pipe_remount_trigger_[1], buf, buf_size);
252 }
253
254
255 ✗ void FuseRemounter::SetOfflineMode(bool value) {
256 ✗ if (value == offline_mode_)
257 ✗ return;
258 ✗ offline_mode_ = value;
259
260 ✗ if (offline_mode_) {
261 ✗ LogCvmfs(kLogCvmfs, kLogDebug | kLogSyslogWarn,
262 "warning, could not apply updated catalog revision, "
263 "entering offline mode");
264 ✗ mountpoint_->file_system()->io_error_info()->AddIoError();
265 } else {
266 ✗ LogCvmfs(kLogCvmfs, kLogDebug | kLogSyslog, "recovered from offline mode");
267 }
268 }
269
270
271 ✗ void FuseRemounter::Spawn() {
272 ✗ invalidator_->Spawn();
273 ✗ if (!mountpoint_->fixed_catalog()) {
274 ✗ MakePipe(pipe_remount_trigger_);
275 ✗ const int retval = pthread_create(&thread_remount_trigger_, NULL,
276 MainRemountTrigger, this);
277 ✗ assert(retval == 0);
278
279 ✗ SetOfflineMode(mountpoint_->catalog_mgr()->offline_mode());
280 ✗ const unsigned ttl = offline_mode_ ? MountPoint::kShortTermTTL
281 ✗ : mountpoint_->GetEffectiveTtlSec();
282 ✗ catalogs_valid_until_ = time(NULL) + ttl;
283 ✗ SetAlarm(ttl);
284 }
285 }
286
287
288 /**
289 * Applies a previously started remount operation. This is called from the
290 * fuse callbacks or from CheckSynchronously(). Usually, the method quits
291 * immediately except when a new catalog is available and the kernel caches are
292 * flushed.
293 */
294 ✗ void FuseRemounter::TryFinish(const shash::Any &root_hash) {
295 ✗ const FenceGuard fence_guard(&fence_maintenance_);
296 ✗ if (IsInMaintenanceMode())
297 ✗ return;
298 ✗ if (!EnterCriticalSection())
299 ✗ return;
300 ✗ if (!IsInDrainoutMode()) {
301 ✗ LeaveCriticalSection();
302 ✗ return;
303 }
304
305 // No one else is in this code path and we have a valid FuseInvalidator handle
306
307 ✗ if (!invalidator_handle_.IsDone()) {
308 ✗ LeaveCriticalSection();
309 ✗ return;
310 }
311 ✗ LogCvmfs(kLogCvmfs, kLogDebug, "caches drained out, applying new catalog");
312
313 // No new inserts into caches
314 ✗ mountpoint_->inode_cache()->Pause();
315 ✗ mountpoint_->path_cache()->Pause();
316 ✗ mountpoint_->md5path_cache()->Pause();
317 ✗ mountpoint_->inode_cache()->Drop();
318 ✗ mountpoint_->path_cache()->Drop();
319 ✗ mountpoint_->md5path_cache()->Drop();
320
321 // Ensure that all Fuse callbacks left the catalog query code
322 ✗ fence_->Drain();
323 catalog::LoadReturn retval;
324 ✗ if (root_hash.IsNull()) {
325 ✗ retval = mountpoint_->catalog_mgr()->Remount();
326 } else {
327 ✗ retval = mountpoint_->catalog_mgr()->ChangeRoot(root_hash);
328 }
329 ✗ if (mountpoint_->inode_annotation()) {
330 ✗ inode_generation_info_->inode_generation = mountpoint_->inode_annotation()
331 ✗ ->GetGeneration();
332 }
333 ✗ mountpoint_->ReEvaluateAuthz();
334 ✗ fence_->Open();
335
336 ✗ mountpoint_->inode_cache()->Resume();
337 ✗ mountpoint_->path_cache()->Resume();
338 ✗ mountpoint_->md5path_cache()->Resume();
339
340 ✗ atomic_xadd32(&drainout_mode_, -2); // 2 --> 0, end of drainout mode
341
342 ✗ if ((retval == catalog::kLoadFail) || (retval == catalog::kLoadNoSpace)) {
343 // Can temporarily "escape" offline mode if update came from updated
344 // alien cache
345 ✗ SetOfflineMode(true);
346 ✗ catalogs_valid_until_ = time(NULL) + MountPoint::kShortTermTTL;
347 ✗ SetAlarm(MountPoint::kShortTermTTL);
348 } else {
349 ✗ SetOfflineMode(false);
350 ✗ LogCvmfs(kLogCvmfs, kLogSyslog, "switched to catalog revision %" PRIu64,
351 ✗ mountpoint_->catalog_mgr()->GetRevision());
352 ✗ catalogs_valid_until_ = time(NULL) + mountpoint_->GetEffectiveTtlSec();
353 ✗ SetAlarm(mountpoint_->GetEffectiveTtlSec());
354 }
355
356 ✗ LeaveCriticalSection();
357 }
358