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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/io/ImageRequestWQ.h" | |
5 | #include "common/errno.h" | |
6 | #include "librbd/ExclusiveLock.h" | |
7 | #include "librbd/ImageCtx.h" | |
8 | #include "librbd/ImageState.h" | |
9 | #include "librbd/internal.h" | |
10 | #include "librbd/Utils.h" | |
11 | #include "librbd/exclusive_lock/Policy.h" | |
12 | #include "librbd/io/AioCompletion.h" | |
13 | #include "librbd/io/ImageRequest.h" | |
14 | ||
15 | #define dout_subsys ceph_subsys_rbd | |
16 | #undef dout_prefix | |
17 | #define dout_prefix *_dout << "librbd::io::ImageRequestWQ: " << this \ | |
18 | << " " << __func__ << ": " | |
19 | ||
20 | namespace librbd { | |
21 | namespace io { | |
22 | ||
23 | ImageRequestWQ::ImageRequestWQ(ImageCtx *image_ctx, const string &name, | |
24 | time_t ti, ThreadPool *tp) | |
25 | : ThreadPool::PointerWQ<ImageRequest<> >(name, ti, 0, tp), | |
26 | m_image_ctx(*image_ctx), | |
27 | m_lock(util::unique_lock_name("ImageRequestWQ::m_lock", this)), | |
28 | m_write_blockers(0), m_in_progress_writes(0), m_queued_reads(0), | |
29 | m_queued_writes(0), m_in_flight_ops(0), m_refresh_in_progress(false), | |
30 | m_shutdown(false), m_on_shutdown(nullptr) { | |
31 | CephContext *cct = m_image_ctx.cct; | |
32 | ldout(cct, 5) << "ictx=" << image_ctx << dendl; | |
33 | tp->add_work_queue(this); | |
34 | } | |
35 | ||
36 | ssize_t ImageRequestWQ::read(uint64_t off, uint64_t len, | |
37 | ReadResult &&read_result, int op_flags) { | |
38 | CephContext *cct = m_image_ctx.cct; | |
39 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", off=" << off << ", " | |
40 | << "len = " << len << dendl; | |
41 | ||
42 | C_SaferCond cond; | |
43 | AioCompletion *c = AioCompletion::create(&cond); | |
44 | aio_read(c, off, len, std::move(read_result), op_flags, false); | |
45 | return cond.wait(); | |
46 | } | |
47 | ||
48 | ssize_t ImageRequestWQ::write(uint64_t off, uint64_t len, | |
49 | bufferlist &&bl, int op_flags) { | |
50 | CephContext *cct = m_image_ctx.cct; | |
51 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", off=" << off << ", " | |
52 | << "len = " << len << dendl; | |
53 | ||
54 | m_image_ctx.snap_lock.get_read(); | |
55 | int r = clip_io(util::get_image_ctx(&m_image_ctx), off, &len); | |
56 | m_image_ctx.snap_lock.put_read(); | |
57 | if (r < 0) { | |
58 | lderr(cct) << "invalid IO request: " << cpp_strerror(r) << dendl; | |
59 | return r; | |
60 | } | |
61 | ||
62 | C_SaferCond cond; | |
63 | AioCompletion *c = AioCompletion::create(&cond); | |
64 | aio_write(c, off, len, std::move(bl), op_flags, false); | |
65 | ||
66 | r = cond.wait(); | |
67 | if (r < 0) { | |
68 | return r; | |
69 | } | |
70 | return len; | |
71 | } | |
72 | ||
73 | ssize_t ImageRequestWQ::discard(uint64_t off, uint64_t len, bool skip_partial_discard) { | |
74 | CephContext *cct = m_image_ctx.cct; | |
75 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", off=" << off << ", " | |
76 | << "len = " << len << dendl; | |
77 | ||
78 | m_image_ctx.snap_lock.get_read(); | |
79 | int r = clip_io(util::get_image_ctx(&m_image_ctx), off, &len); | |
80 | m_image_ctx.snap_lock.put_read(); | |
81 | if (r < 0) { | |
82 | lderr(cct) << "invalid IO request: " << cpp_strerror(r) << dendl; | |
83 | return r; | |
84 | } | |
85 | ||
86 | C_SaferCond cond; | |
87 | AioCompletion *c = AioCompletion::create(&cond); | |
88 | aio_discard(c, off, len, skip_partial_discard, false); | |
89 | ||
90 | r = cond.wait(); | |
91 | if (r < 0) { | |
92 | return r; | |
93 | } | |
94 | return len; | |
95 | } | |
96 | ||
97 | ssize_t ImageRequestWQ::writesame(uint64_t off, uint64_t len, bufferlist &&bl, | |
98 | int op_flags) { | |
99 | CephContext *cct = m_image_ctx.cct; | |
100 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", off=" << off << ", " | |
101 | << "len = " << len << ", data_len " << bl.length() << dendl; | |
102 | ||
103 | m_image_ctx.snap_lock.get_read(); | |
104 | int r = clip_io(util::get_image_ctx(&m_image_ctx), off, &len); | |
105 | m_image_ctx.snap_lock.put_read(); | |
106 | if (r < 0) { | |
107 | lderr(cct) << "invalid IO request: " << cpp_strerror(r) << dendl; | |
108 | return r; | |
109 | } | |
110 | ||
111 | C_SaferCond cond; | |
112 | AioCompletion *c = AioCompletion::create(&cond); | |
113 | aio_writesame(c, off, len, std::move(bl), op_flags, false); | |
114 | ||
115 | r = cond.wait(); | |
116 | if (r < 0) { | |
117 | return r; | |
118 | } | |
119 | return len; | |
120 | } | |
121 | ||
122 | void ImageRequestWQ::aio_read(AioCompletion *c, uint64_t off, uint64_t len, | |
123 | ReadResult &&read_result, int op_flags, | |
124 | bool native_async) { | |
125 | c->init_time(&m_image_ctx, AIO_TYPE_READ); | |
126 | CephContext *cct = m_image_ctx.cct; | |
127 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", " | |
128 | << "completion=" << c << ", off=" << off << ", " | |
129 | << "len=" << len << ", " << "flags=" << op_flags << dendl; | |
130 | ||
131 | if (native_async && m_image_ctx.event_socket.is_valid()) { | |
132 | c->set_event_notify(true); | |
133 | } | |
134 | ||
135 | if (!start_in_flight_op(c)) { | |
136 | return; | |
137 | } | |
138 | ||
139 | RWLock::RLocker owner_locker(m_image_ctx.owner_lock); | |
140 | ||
141 | // if journaling is enabled -- we need to replay the journal because | |
142 | // it might contain an uncommitted write | |
143 | bool lock_required; | |
144 | { | |
145 | RWLock::RLocker locker(m_lock); | |
146 | lock_required = m_require_lock_on_read; | |
147 | } | |
148 | ||
149 | if (m_image_ctx.non_blocking_aio || writes_blocked() || !writes_empty() || | |
150 | lock_required) { | |
151 | queue(new ImageReadRequest<>(m_image_ctx, c, {{off, len}}, | |
152 | std::move(read_result), op_flags)); | |
153 | } else { | |
154 | c->start_op(); | |
155 | ImageRequest<>::aio_read(&m_image_ctx, c, {{off, len}}, | |
156 | std::move(read_result), op_flags); | |
157 | finish_in_flight_op(); | |
158 | } | |
159 | } | |
160 | ||
161 | void ImageRequestWQ::aio_write(AioCompletion *c, uint64_t off, uint64_t len, | |
162 | bufferlist &&bl, int op_flags, | |
163 | bool native_async) { | |
164 | c->init_time(&m_image_ctx, AIO_TYPE_WRITE); | |
165 | CephContext *cct = m_image_ctx.cct; | |
166 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", " | |
167 | << "completion=" << c << ", off=" << off << ", " | |
168 | << "len=" << len << ", flags=" << op_flags << dendl; | |
169 | ||
170 | if (native_async && m_image_ctx.event_socket.is_valid()) { | |
171 | c->set_event_notify(true); | |
172 | } | |
173 | ||
174 | if (!start_in_flight_op(c)) { | |
175 | return; | |
176 | } | |
177 | ||
178 | RWLock::RLocker owner_locker(m_image_ctx.owner_lock); | |
179 | if (m_image_ctx.non_blocking_aio || writes_blocked()) { | |
180 | queue(new ImageWriteRequest<>(m_image_ctx, c, {{off, len}}, | |
181 | std::move(bl), op_flags)); | |
182 | } else { | |
183 | c->start_op(); | |
184 | ImageRequest<>::aio_write(&m_image_ctx, c, {{off, len}}, | |
185 | std::move(bl), op_flags); | |
186 | finish_in_flight_op(); | |
187 | } | |
188 | } | |
189 | ||
190 | void ImageRequestWQ::aio_discard(AioCompletion *c, uint64_t off, | |
191 | uint64_t len, bool skip_partial_discard, | |
192 | bool native_async) { | |
193 | c->init_time(&m_image_ctx, AIO_TYPE_DISCARD); | |
194 | CephContext *cct = m_image_ctx.cct; | |
195 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", " | |
196 | << "completion=" << c << ", off=" << off << ", len=" << len | |
197 | << dendl; | |
198 | ||
199 | if (native_async && m_image_ctx.event_socket.is_valid()) { | |
200 | c->set_event_notify(true); | |
201 | } | |
202 | ||
203 | if (!start_in_flight_op(c)) { | |
204 | return; | |
205 | } | |
206 | ||
207 | RWLock::RLocker owner_locker(m_image_ctx.owner_lock); | |
208 | if (m_image_ctx.non_blocking_aio || writes_blocked()) { | |
209 | queue(new ImageDiscardRequest<>(m_image_ctx, c, off, len, skip_partial_discard)); | |
210 | } else { | |
211 | c->start_op(); | |
212 | ImageRequest<>::aio_discard(&m_image_ctx, c, off, len, skip_partial_discard); | |
213 | finish_in_flight_op(); | |
214 | } | |
215 | } | |
216 | ||
217 | void ImageRequestWQ::aio_flush(AioCompletion *c, bool native_async) { | |
218 | c->init_time(&m_image_ctx, AIO_TYPE_FLUSH); | |
219 | CephContext *cct = m_image_ctx.cct; | |
220 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", " | |
221 | << "completion=" << c << dendl; | |
222 | ||
223 | if (native_async && m_image_ctx.event_socket.is_valid()) { | |
224 | c->set_event_notify(true); | |
225 | } | |
226 | ||
227 | if (!start_in_flight_op(c)) { | |
228 | return; | |
229 | } | |
230 | ||
231 | RWLock::RLocker owner_locker(m_image_ctx.owner_lock); | |
232 | if (m_image_ctx.non_blocking_aio || writes_blocked() || !writes_empty()) { | |
233 | queue(new ImageFlushRequest<>(m_image_ctx, c)); | |
234 | } else { | |
235 | ImageRequest<>::aio_flush(&m_image_ctx, c); | |
236 | finish_in_flight_op(); | |
237 | } | |
238 | } | |
239 | ||
240 | void ImageRequestWQ::aio_writesame(AioCompletion *c, uint64_t off, uint64_t len, | |
241 | bufferlist &&bl, int op_flags, | |
242 | bool native_async) { | |
243 | c->init_time(&m_image_ctx, AIO_TYPE_WRITESAME); | |
244 | CephContext *cct = m_image_ctx.cct; | |
245 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", " | |
246 | << "completion=" << c << ", off=" << off << ", " | |
247 | << "len=" << len << ", data_len = " << bl.length() << ", " | |
248 | << "flags=" << op_flags << dendl; | |
249 | ||
250 | if (native_async && m_image_ctx.event_socket.is_valid()) { | |
251 | c->set_event_notify(true); | |
252 | } | |
253 | ||
254 | if (!start_in_flight_op(c)) { | |
255 | return; | |
256 | } | |
257 | ||
258 | RWLock::RLocker owner_locker(m_image_ctx.owner_lock); | |
259 | if (m_image_ctx.non_blocking_aio || writes_blocked()) { | |
260 | queue(new ImageWriteSameRequest<>(m_image_ctx, c, off, len, std::move(bl), | |
261 | op_flags)); | |
262 | } else { | |
263 | c->start_op(); | |
264 | ImageRequest<>::aio_writesame(&m_image_ctx, c, off, len, std::move(bl), | |
265 | op_flags); | |
266 | finish_in_flight_op(); | |
267 | } | |
268 | } | |
269 | ||
270 | void ImageRequestWQ::shut_down(Context *on_shutdown) { | |
271 | assert(m_image_ctx.owner_lock.is_locked()); | |
272 | ||
273 | { | |
274 | RWLock::WLocker locker(m_lock); | |
275 | assert(!m_shutdown); | |
276 | m_shutdown = true; | |
277 | ||
278 | CephContext *cct = m_image_ctx.cct; | |
279 | ldout(cct, 5) << __func__ << ": in_flight=" << m_in_flight_ops.load() | |
280 | << dendl; | |
281 | if (m_in_flight_ops > 0) { | |
282 | m_on_shutdown = on_shutdown; | |
283 | return; | |
284 | } | |
285 | } | |
286 | ||
287 | // ensure that all in-flight IO is flushed | |
288 | m_image_ctx.flush(on_shutdown); | |
289 | } | |
290 | ||
291 | bool ImageRequestWQ::is_lock_request_needed() const { | |
292 | RWLock::RLocker locker(m_lock); | |
293 | return (m_queued_writes > 0 || | |
294 | (m_require_lock_on_read && m_queued_reads > 0)); | |
295 | } | |
296 | ||
297 | int ImageRequestWQ::block_writes() { | |
298 | C_SaferCond cond_ctx; | |
299 | block_writes(&cond_ctx); | |
300 | return cond_ctx.wait(); | |
301 | } | |
302 | ||
303 | void ImageRequestWQ::block_writes(Context *on_blocked) { | |
304 | assert(m_image_ctx.owner_lock.is_locked()); | |
305 | CephContext *cct = m_image_ctx.cct; | |
306 | ||
307 | { | |
308 | RWLock::WLocker locker(m_lock); | |
309 | ++m_write_blockers; | |
310 | ldout(cct, 5) << &m_image_ctx << ", " << "num=" | |
311 | << m_write_blockers << dendl; | |
312 | if (!m_write_blocker_contexts.empty() || m_in_progress_writes > 0) { | |
313 | m_write_blocker_contexts.push_back(on_blocked); | |
314 | return; | |
315 | } | |
316 | } | |
317 | ||
318 | // ensure that all in-flight IO is flushed | |
319 | m_image_ctx.flush(on_blocked); | |
320 | } | |
321 | ||
322 | void ImageRequestWQ::unblock_writes() { | |
323 | CephContext *cct = m_image_ctx.cct; | |
324 | ||
325 | bool wake_up = false; | |
326 | { | |
327 | RWLock::WLocker locker(m_lock); | |
328 | assert(m_write_blockers > 0); | |
329 | --m_write_blockers; | |
330 | ||
331 | ldout(cct, 5) << &m_image_ctx << ", " << "num=" | |
332 | << m_write_blockers << dendl; | |
333 | if (m_write_blockers == 0) { | |
334 | wake_up = true; | |
335 | } | |
336 | } | |
337 | ||
338 | if (wake_up) { | |
339 | signal(); | |
340 | } | |
341 | } | |
342 | ||
343 | void ImageRequestWQ::set_require_lock_on_read() { | |
344 | CephContext *cct = m_image_ctx.cct; | |
345 | ldout(cct, 20) << dendl; | |
346 | ||
347 | RWLock::WLocker locker(m_lock); | |
348 | m_require_lock_on_read = true; | |
349 | } | |
350 | ||
351 | void ImageRequestWQ::clear_require_lock_on_read() { | |
352 | CephContext *cct = m_image_ctx.cct; | |
353 | ldout(cct, 20) << dendl; | |
354 | ||
355 | { | |
356 | RWLock::WLocker locker(m_lock); | |
357 | if (!m_require_lock_on_read) { | |
358 | return; | |
359 | } | |
360 | ||
361 | m_require_lock_on_read = false; | |
362 | } | |
363 | signal(); | |
364 | } | |
365 | ||
366 | void *ImageRequestWQ::_void_dequeue() { | |
367 | ImageRequest<> *peek_item = front(); | |
368 | ||
369 | // no IO ops available or refresh in-progress (IO stalled) | |
370 | if (peek_item == nullptr || m_refresh_in_progress) { | |
371 | return nullptr; | |
372 | } | |
373 | ||
374 | bool refresh_required = m_image_ctx.state->is_refresh_required(); | |
375 | { | |
376 | RWLock::RLocker locker(m_lock); | |
377 | if (peek_item->is_write_op()) { | |
378 | if (m_write_blockers > 0) { | |
379 | return nullptr; | |
380 | } | |
381 | ||
382 | // refresh will requeue the op -- don't count it as in-progress | |
383 | if (!refresh_required) { | |
384 | m_in_progress_writes++; | |
385 | } | |
386 | } else if (m_require_lock_on_read) { | |
387 | return nullptr; | |
388 | } | |
389 | } | |
390 | ||
391 | ImageRequest<> *item = reinterpret_cast<ImageRequest<> *>( | |
392 | ThreadPool::PointerWQ<ImageRequest<> >::_void_dequeue()); | |
393 | assert(peek_item == item); | |
394 | ||
395 | if (refresh_required) { | |
396 | ldout(m_image_ctx.cct, 15) << "image refresh required: delaying IO " << item | |
397 | << dendl; | |
398 | ||
399 | // stall IO until the refresh completes | |
400 | m_refresh_in_progress = true; | |
401 | ||
402 | get_pool_lock().Unlock(); | |
403 | m_image_ctx.state->refresh(new C_RefreshFinish(this, item)); | |
404 | get_pool_lock().Lock(); | |
405 | return nullptr; | |
406 | } | |
407 | ||
408 | item->start_op(); | |
409 | return item; | |
410 | } | |
411 | ||
412 | void ImageRequestWQ::process(ImageRequest<> *req) { | |
413 | CephContext *cct = m_image_ctx.cct; | |
414 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", " | |
415 | << "req=" << req << dendl; | |
416 | ||
417 | req->send(); | |
418 | ||
419 | finish_queued_op(req); | |
420 | if (req->is_write_op()) { | |
421 | finish_in_progress_write(); | |
422 | } | |
423 | delete req; | |
424 | ||
425 | finish_in_flight_op(); | |
426 | } | |
427 | ||
428 | void ImageRequestWQ::finish_queued_op(ImageRequest<> *req) { | |
429 | RWLock::RLocker locker(m_lock); | |
430 | if (req->is_write_op()) { | |
431 | assert(m_queued_writes > 0); | |
432 | m_queued_writes--; | |
433 | } else { | |
434 | assert(m_queued_reads > 0); | |
435 | m_queued_reads--; | |
436 | } | |
437 | } | |
438 | ||
439 | void ImageRequestWQ::finish_in_progress_write() { | |
440 | bool writes_blocked = false; | |
441 | { | |
442 | RWLock::RLocker locker(m_lock); | |
443 | assert(m_in_progress_writes > 0); | |
444 | if (--m_in_progress_writes == 0 && | |
445 | !m_write_blocker_contexts.empty()) { | |
446 | writes_blocked = true; | |
447 | } | |
448 | } | |
449 | ||
450 | if (writes_blocked) { | |
451 | m_image_ctx.flush(new C_BlockedWrites(this)); | |
452 | } | |
453 | } | |
454 | ||
455 | int ImageRequestWQ::start_in_flight_op(AioCompletion *c) { | |
456 | RWLock::RLocker locker(m_lock); | |
457 | ||
458 | if (m_shutdown) { | |
459 | CephContext *cct = m_image_ctx.cct; | |
460 | lderr(cct) << "IO received on closed image" << dendl; | |
461 | ||
462 | c->fail(-ESHUTDOWN); | |
463 | return false; | |
464 | } | |
465 | ||
466 | m_in_flight_ops++; | |
467 | return true; | |
468 | } | |
469 | ||
470 | void ImageRequestWQ::finish_in_flight_op() { | |
471 | Context *on_shutdown; | |
472 | { | |
473 | RWLock::RLocker locker(m_lock); | |
474 | if (--m_in_flight_ops > 0 || !m_shutdown) { | |
475 | return; | |
476 | } | |
477 | on_shutdown = m_on_shutdown; | |
478 | } | |
479 | ||
480 | CephContext *cct = m_image_ctx.cct; | |
481 | ldout(cct, 5) << "completing shut down" << dendl; | |
482 | ||
483 | assert(on_shutdown != nullptr); | |
484 | m_image_ctx.flush(on_shutdown); | |
485 | } | |
486 | ||
487 | bool ImageRequestWQ::is_lock_required() const { | |
488 | assert(m_image_ctx.owner_lock.is_locked()); | |
489 | if (m_image_ctx.exclusive_lock == NULL) { | |
490 | return false; | |
491 | } | |
492 | ||
493 | return (!m_image_ctx.exclusive_lock->is_lock_owner()); | |
494 | } | |
495 | ||
496 | void ImageRequestWQ::queue(ImageRequest<> *req) { | |
497 | CephContext *cct = m_image_ctx.cct; | |
498 | ldout(cct, 20) << "ictx=" << &m_image_ctx << ", " | |
499 | << "req=" << req << dendl; | |
500 | ||
501 | assert(m_image_ctx.owner_lock.is_locked()); | |
502 | bool write_op = req->is_write_op(); | |
503 | bool lock_required = (m_image_ctx.exclusive_lock != nullptr && | |
504 | ((write_op && is_lock_required()) || | |
505 | (!write_op && m_require_lock_on_read))); | |
506 | ||
507 | if (lock_required && !m_image_ctx.get_exclusive_lock_policy()->may_auto_request_lock()) { | |
508 | lderr(cct) << "op requires exclusive lock" << dendl; | |
509 | req->fail(-EROFS); | |
510 | delete req; | |
511 | finish_in_flight_op(); | |
512 | return; | |
513 | } | |
514 | ||
515 | if (write_op) { | |
516 | m_queued_writes++; | |
517 | } else { | |
518 | m_queued_reads++; | |
519 | } | |
520 | ||
521 | ThreadPool::PointerWQ<ImageRequest<> >::queue(req); | |
522 | ||
523 | if (lock_required) { | |
524 | m_image_ctx.exclusive_lock->acquire_lock(nullptr); | |
525 | } | |
526 | } | |
527 | ||
528 | void ImageRequestWQ::handle_refreshed(int r, ImageRequest<> *req) { | |
529 | CephContext *cct = m_image_ctx.cct; | |
530 | ldout(cct, 15) << "resuming IO after image refresh: r=" << r << ", " | |
531 | << "req=" << req << dendl; | |
532 | if (r < 0) { | |
533 | process_finish(); | |
534 | req->fail(r); | |
535 | finish_queued_op(req); | |
536 | delete req; | |
537 | finish_in_flight_op(); | |
538 | } else { | |
539 | // since IO was stalled for refresh -- original IO order is preserved | |
540 | // if we requeue this op for work queue processing | |
541 | requeue(req); | |
542 | } | |
543 | ||
544 | m_refresh_in_progress = false; | |
545 | signal(); | |
546 | ||
547 | // refresh might have enabled exclusive lock -- IO stalled until | |
548 | // we acquire the lock | |
549 | RWLock::RLocker owner_locker(m_image_ctx.owner_lock); | |
550 | if (is_lock_required() && is_lock_request_needed()) { | |
551 | m_image_ctx.exclusive_lock->acquire_lock(nullptr); | |
552 | } | |
553 | } | |
554 | ||
555 | void ImageRequestWQ::handle_blocked_writes(int r) { | |
556 | Contexts contexts; | |
557 | { | |
558 | RWLock::WLocker locker(m_lock); | |
559 | contexts.swap(m_write_blocker_contexts); | |
560 | } | |
561 | ||
562 | for (auto ctx : contexts) { | |
563 | ctx->complete(0); | |
564 | } | |
565 | } | |
566 | ||
567 | } // namespace io | |
568 | } // namespace librbd |