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7c673cae FG |
1 | // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- |
2 | // vim: ts=8 sw=2 smarttab | |
3 | ||
4 | #include "librbd/ExclusiveLock.h" | |
31f18b77 | 5 | #include "librbd/ImageCtx.h" |
7c673cae FG |
6 | #include "librbd/ImageWatcher.h" |
7 | #include "librbd/ImageState.h" | |
8 | #include "librbd/exclusive_lock/PreAcquireRequest.h" | |
9 | #include "librbd/exclusive_lock/PostAcquireRequest.h" | |
10 | #include "librbd/exclusive_lock/PreReleaseRequest.h" | |
11 | #include "librbd/io/ImageRequestWQ.h" | |
12 | #include "librbd/Utils.h" | |
13 | #include "common/Mutex.h" | |
14 | #include "common/dout.h" | |
15 | ||
16 | #define dout_subsys ceph_subsys_rbd | |
17 | #undef dout_prefix | |
18 | #define dout_prefix *_dout << "librbd::ExclusiveLock: " << this << " " \ | |
19 | << __func__ | |
20 | ||
21 | namespace librbd { | |
22 | ||
23 | using namespace exclusive_lock; | |
24 | ||
25 | template <typename I> | |
26 | using ML = ManagedLock<I>; | |
27 | ||
28 | template <typename I> | |
29 | ExclusiveLock<I>::ExclusiveLock(I &image_ctx) | |
30 | : ML<I>(image_ctx.md_ctx, image_ctx.op_work_queue, image_ctx.header_oid, | |
31 | image_ctx.image_watcher, managed_lock::EXCLUSIVE, | |
32 | image_ctx.blacklist_on_break_lock, | |
33 | image_ctx.blacklist_expire_seconds), | |
34 | m_image_ctx(image_ctx) { | |
35 | Mutex::Locker locker(ML<I>::m_lock); | |
36 | ML<I>::set_state_uninitialized(); | |
37 | } | |
38 | ||
39 | template <typename I> | |
40 | bool ExclusiveLock<I>::accept_requests(int *ret_val) const { | |
41 | Mutex::Locker locker(ML<I>::m_lock); | |
42 | ||
43 | bool accept_requests = (!ML<I>::is_state_shutdown() && | |
44 | ML<I>::is_state_locked() && | |
45 | m_request_blocked_count == 0); | |
31f18b77 FG |
46 | if (ret_val != nullptr) { |
47 | *ret_val = m_request_blocked_ret_val; | |
48 | } | |
7c673cae FG |
49 | |
50 | ldout(m_image_ctx.cct, 20) << "=" << accept_requests << dendl; | |
51 | return accept_requests; | |
52 | } | |
53 | ||
31f18b77 FG |
54 | template <typename I> |
55 | bool ExclusiveLock<I>::accept_ops() const { | |
56 | Mutex::Locker locker(ML<I>::m_lock); | |
57 | bool accept = accept_ops(ML<I>::m_lock); | |
58 | ldout(m_image_ctx.cct, 20) << "=" << accept << dendl; | |
59 | return accept; | |
60 | } | |
61 | ||
62 | template <typename I> | |
63 | bool ExclusiveLock<I>::accept_ops(const Mutex &lock) const { | |
64 | return (!ML<I>::is_state_shutdown() && | |
65 | (ML<I>::is_state_locked() || ML<I>::is_state_post_acquiring())); | |
66 | } | |
67 | ||
7c673cae FG |
68 | template <typename I> |
69 | void ExclusiveLock<I>::block_requests(int r) { | |
70 | Mutex::Locker locker(ML<I>::m_lock); | |
71 | ||
72 | m_request_blocked_count++; | |
73 | if (m_request_blocked_ret_val == 0) { | |
74 | m_request_blocked_ret_val = r; | |
75 | } | |
76 | ||
77 | ldout(m_image_ctx.cct, 20) << dendl; | |
78 | } | |
79 | ||
80 | template <typename I> | |
81 | void ExclusiveLock<I>::unblock_requests() { | |
82 | Mutex::Locker locker(ML<I>::m_lock); | |
83 | ||
84 | assert(m_request_blocked_count > 0); | |
85 | m_request_blocked_count--; | |
86 | if (m_request_blocked_count == 0) { | |
87 | m_request_blocked_ret_val = 0; | |
88 | } | |
89 | ||
90 | ldout(m_image_ctx.cct, 20) << dendl; | |
91 | } | |
92 | ||
93 | template <typename I> | |
94 | void ExclusiveLock<I>::init(uint64_t features, Context *on_init) { | |
95 | assert(m_image_ctx.owner_lock.is_locked()); | |
96 | ldout(m_image_ctx.cct, 10) << dendl; | |
97 | ||
98 | { | |
99 | Mutex::Locker locker(ML<I>::m_lock); | |
100 | ML<I>::set_state_initializing(); | |
101 | } | |
102 | ||
103 | m_image_ctx.io_work_queue->block_writes(new C_InitComplete(this, features, | |
104 | on_init)); | |
105 | } | |
106 | ||
107 | template <typename I> | |
108 | void ExclusiveLock<I>::shut_down(Context *on_shut_down) { | |
109 | ldout(m_image_ctx.cct, 10) << dendl; | |
110 | ||
111 | ML<I>::shut_down(on_shut_down); | |
112 | ||
113 | // if stalled in request state machine -- abort | |
114 | handle_peer_notification(0); | |
115 | } | |
116 | ||
117 | template <typename I> | |
118 | void ExclusiveLock<I>::handle_peer_notification(int r) { | |
119 | Mutex::Locker locker(ML<I>::m_lock); | |
120 | if (!ML<I>::is_state_waiting_for_lock()) { | |
121 | return; | |
122 | } | |
123 | ||
124 | ldout(m_image_ctx.cct, 10) << dendl; | |
125 | assert(ML<I>::is_action_acquire_lock()); | |
126 | ||
127 | m_acquire_lock_peer_ret_val = r; | |
128 | ML<I>::execute_next_action(); | |
129 | } | |
130 | ||
31f18b77 FG |
131 | template <typename I> |
132 | Context *ExclusiveLock<I>::start_op() { | |
133 | assert(m_image_ctx.owner_lock.is_locked()); | |
134 | Mutex::Locker locker(ML<I>::m_lock); | |
135 | ||
136 | if (!accept_ops(ML<I>::m_lock)) { | |
137 | return nullptr; | |
138 | } | |
139 | ||
140 | m_async_op_tracker.start_op(); | |
141 | return new FunctionContext([this](int r) { | |
142 | m_async_op_tracker.finish_op(); | |
143 | }); | |
144 | } | |
145 | ||
7c673cae FG |
146 | template <typename I> |
147 | void ExclusiveLock<I>::handle_init_complete(uint64_t features) { | |
31f18b77 | 148 | ldout(m_image_ctx.cct, 10) << ": features=" << features << dendl; |
7c673cae | 149 | |
224ce89b WB |
150 | { |
151 | RWLock::RLocker owner_locker(m_image_ctx.owner_lock); | |
152 | if (m_image_ctx.clone_copy_on_read || | |
153 | (features & RBD_FEATURE_JOURNALING) != 0) { | |
154 | m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_BOTH, true); | |
155 | } else { | |
156 | m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_WRITE, true); | |
157 | } | |
7c673cae FG |
158 | } |
159 | ||
160 | Mutex::Locker locker(ML<I>::m_lock); | |
161 | ML<I>::set_state_unlocked(); | |
162 | } | |
163 | ||
164 | template <typename I> | |
165 | void ExclusiveLock<I>::shutdown_handler(int r, Context *on_finish) { | |
166 | ldout(m_image_ctx.cct, 10) << dendl; | |
167 | ||
168 | { | |
169 | RWLock::WLocker owner_locker(m_image_ctx.owner_lock); | |
224ce89b | 170 | m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_BOTH, false); |
7c673cae FG |
171 | m_image_ctx.exclusive_lock = nullptr; |
172 | } | |
173 | ||
174 | m_image_ctx.io_work_queue->unblock_writes(); | |
175 | m_image_ctx.image_watcher->flush(on_finish); | |
176 | } | |
177 | ||
178 | template <typename I> | |
179 | void ExclusiveLock<I>::pre_acquire_lock_handler(Context *on_finish) { | |
180 | ldout(m_image_ctx.cct, 10) << dendl; | |
181 | ||
182 | int acquire_lock_peer_ret_val = 0; | |
183 | { | |
184 | Mutex::Locker locker(ML<I>::m_lock); | |
185 | std::swap(acquire_lock_peer_ret_val, m_acquire_lock_peer_ret_val); | |
186 | } | |
187 | ||
188 | if (acquire_lock_peer_ret_val == -EROFS) { | |
189 | ldout(m_image_ctx.cct, 10) << ": peer nacked lock request" << dendl; | |
190 | on_finish->complete(acquire_lock_peer_ret_val); | |
191 | return; | |
192 | } | |
193 | ||
194 | PreAcquireRequest<I> *req = PreAcquireRequest<I>::create(m_image_ctx, | |
195 | on_finish); | |
196 | m_image_ctx.op_work_queue->queue(new FunctionContext([req](int r) { | |
197 | req->send(); | |
198 | })); | |
199 | } | |
200 | ||
201 | template <typename I> | |
202 | void ExclusiveLock<I>::post_acquire_lock_handler(int r, Context *on_finish) { | |
203 | ldout(m_image_ctx.cct, 10) << ": r=" << r << dendl; | |
204 | ||
205 | if (r == -EROFS) { | |
206 | // peer refused to release the exclusive lock | |
207 | on_finish->complete(r); | |
208 | return; | |
209 | } else if (r < 0) { | |
210 | ML<I>::m_lock.Lock(); | |
211 | assert(ML<I>::is_state_acquiring()); | |
212 | ||
213 | // PostAcquire state machine will not run, so we need complete prepare | |
214 | m_image_ctx.state->handle_prepare_lock_complete(); | |
215 | ||
216 | // if lock is in-use by another client, request the lock | |
217 | if (ML<I>::is_action_acquire_lock() && (r == -EBUSY || r == -EAGAIN)) { | |
218 | ML<I>::set_state_waiting_for_lock(); | |
219 | ML<I>::m_lock.Unlock(); | |
220 | ||
221 | // request the lock from a peer | |
222 | m_image_ctx.image_watcher->notify_request_lock(); | |
223 | ||
224 | // inform manage lock that we have interrupted the state machine | |
225 | r = -ECANCELED; | |
226 | } else { | |
227 | ML<I>::m_lock.Unlock(); | |
228 | ||
229 | // clear error if peer owns lock | |
230 | if (r == -EAGAIN) { | |
231 | r = 0; | |
232 | } | |
233 | } | |
234 | ||
235 | on_finish->complete(r); | |
236 | return; | |
237 | } | |
238 | ||
239 | Mutex::Locker locker(ML<I>::m_lock); | |
240 | m_pre_post_callback = on_finish; | |
241 | using EL = ExclusiveLock<I>; | |
242 | PostAcquireRequest<I> *req = PostAcquireRequest<I>::create(m_image_ctx, | |
243 | util::create_context_callback<EL, &EL::handle_post_acquiring_lock>(this), | |
244 | util::create_context_callback<EL, &EL::handle_post_acquired_lock>(this)); | |
245 | ||
246 | m_image_ctx.op_work_queue->queue(new FunctionContext([req](int r) { | |
247 | req->send(); | |
248 | })); | |
249 | } | |
250 | ||
251 | template <typename I> | |
252 | void ExclusiveLock<I>::handle_post_acquiring_lock(int r) { | |
253 | ldout(m_image_ctx.cct, 10) << dendl; | |
254 | ||
255 | Mutex::Locker locker(ML<I>::m_lock); | |
256 | ||
257 | assert(r == 0); | |
258 | ||
259 | // lock is owned at this point | |
260 | ML<I>::set_state_post_acquiring(); | |
261 | } | |
262 | ||
263 | template <typename I> | |
264 | void ExclusiveLock<I>::handle_post_acquired_lock(int r) { | |
265 | ldout(m_image_ctx.cct, 10) << ": r=" << r << dendl; | |
266 | ||
267 | Context *on_finish = nullptr; | |
268 | { | |
269 | Mutex::Locker locker(ML<I>::m_lock); | |
270 | assert(ML<I>::is_state_acquiring() || ML<I>::is_state_post_acquiring()); | |
271 | ||
272 | assert (m_pre_post_callback != nullptr); | |
273 | std::swap(m_pre_post_callback, on_finish); | |
274 | } | |
275 | ||
276 | if (r >= 0) { | |
277 | m_image_ctx.image_watcher->notify_acquired_lock(); | |
224ce89b | 278 | m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_BOTH, false); |
7c673cae FG |
279 | m_image_ctx.io_work_queue->unblock_writes(); |
280 | } | |
281 | ||
282 | on_finish->complete(r); | |
283 | } | |
284 | ||
285 | template <typename I> | |
286 | void ExclusiveLock<I>::pre_release_lock_handler(bool shutting_down, | |
287 | Context *on_finish) { | |
288 | ldout(m_image_ctx.cct, 10) << dendl; | |
289 | Mutex::Locker locker(ML<I>::m_lock); | |
290 | ||
291 | PreReleaseRequest<I> *req = PreReleaseRequest<I>::create( | |
31f18b77 | 292 | m_image_ctx, shutting_down, m_async_op_tracker, on_finish); |
7c673cae FG |
293 | m_image_ctx.op_work_queue->queue(new FunctionContext([req](int r) { |
294 | req->send(); | |
295 | })); | |
296 | } | |
297 | ||
298 | template <typename I> | |
299 | void ExclusiveLock<I>::post_release_lock_handler(bool shutting_down, int r, | |
300 | Context *on_finish) { | |
301 | ldout(m_image_ctx.cct, 10) << ": r=" << r << " shutting_down=" | |
302 | << shutting_down << dendl; | |
303 | if (!shutting_down) { | |
304 | { | |
305 | Mutex::Locker locker(ML<I>::m_lock); | |
306 | assert(ML<I>::is_state_pre_releasing() || ML<I>::is_state_releasing()); | |
307 | } | |
308 | ||
309 | if (r >= 0) { | |
310 | m_image_ctx.image_watcher->notify_released_lock(); | |
7c673cae FG |
311 | } |
312 | } else { | |
313 | { | |
314 | RWLock::WLocker owner_locker(m_image_ctx.owner_lock); | |
224ce89b | 315 | m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_BOTH, false); |
7c673cae FG |
316 | m_image_ctx.exclusive_lock = nullptr; |
317 | } | |
318 | ||
319 | if (r >= 0) { | |
320 | m_image_ctx.io_work_queue->unblock_writes(); | |
321 | } | |
322 | ||
323 | m_image_ctx.image_watcher->notify_released_lock(); | |
324 | } | |
325 | ||
326 | on_finish->complete(r); | |
327 | } | |
328 | ||
31f18b77 FG |
329 | template <typename I> |
330 | void ExclusiveLock<I>::post_reacquire_lock_handler(int r, Context *on_finish) { | |
331 | ldout(m_image_ctx.cct, 10) << dendl; | |
332 | if (r >= 0) { | |
333 | m_image_ctx.image_watcher->notify_acquired_lock(); | |
334 | } | |
335 | ||
336 | on_finish->complete(r); | |
337 | } | |
338 | ||
7c673cae FG |
339 | template <typename I> |
340 | struct ExclusiveLock<I>::C_InitComplete : public Context { | |
341 | ExclusiveLock *exclusive_lock; | |
342 | uint64_t features; | |
343 | Context *on_init; | |
344 | ||
345 | C_InitComplete(ExclusiveLock *exclusive_lock, uint64_t features, | |
346 | Context *on_init) | |
347 | : exclusive_lock(exclusive_lock), features(features), on_init(on_init) { | |
348 | } | |
349 | void finish(int r) override { | |
350 | if (r == 0) { | |
351 | exclusive_lock->handle_init_complete(features); | |
352 | } | |
353 | on_init->complete(r); | |
354 | } | |
355 | }; | |
356 | ||
357 | } // namespace librbd | |
358 | ||
359 | template class librbd::ExclusiveLock<librbd::ImageCtx>; |