1 /* 2 * Copyright (c) 2015 Oracle. All rights reserved. 3 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved. 4 */ 5 6 /* Lightweight memory registration using Fast Registration Work 7 * Requests (FRWR). Also referred to sometimes as FRMR mode. 8 * 9 * FRWR features ordered asynchronous registration and deregistration 10 * of arbitrarily sized memory regions. This is the fastest and safest 11 * but most complex memory registration mode. 12 */ 13 14 /* Normal operation 15 * 16 * A Memory Region is prepared for RDMA READ or WRITE using a FAST_REG 17 * Work Request (frmr_op_map). When the RDMA operation is finished, this 18 * Memory Region is invalidated using a LOCAL_INV Work Request 19 * (frmr_op_unmap). 20 * 21 * Typically these Work Requests are not signaled, and neither are RDMA 22 * SEND Work Requests (with the exception of signaling occasionally to 23 * prevent provider work queue overflows). This greatly reduces HCA 24 * interrupt workload. 25 * 26 * As an optimization, frwr_op_unmap marks MRs INVALID before the 27 * LOCAL_INV WR is posted. If posting succeeds, the MR is placed on 28 * rb_mws immediately so that no work (like managing a linked list 29 * under a spinlock) is needed in the completion upcall. 30 * 31 * But this means that frwr_op_map() can occasionally encounter an MR 32 * that is INVALID but the LOCAL_INV WR has not completed. Work Queue 33 * ordering prevents a subsequent FAST_REG WR from executing against 34 * that MR while it is still being invalidated. 35 */ 36 37 /* Transport recovery 38 * 39 * ->op_map and the transport connect worker cannot run at the same 40 * time, but ->op_unmap can fire while the transport connect worker 41 * is running. Thus MR recovery is handled in ->op_map, to guarantee 42 * that recovered MRs are owned by a sending RPC, and not one where 43 * ->op_unmap could fire at the same time transport reconnect is 44 * being done. 45 * 46 * When the underlying transport disconnects, MRs are left in one of 47 * three states: 48 * 49 * INVALID: The MR was not in use before the QP entered ERROR state. 50 * (Or, the LOCAL_INV WR has not completed or flushed yet). 51 * 52 * STALE: The MR was being registered or unregistered when the QP 53 * entered ERROR state, and the pending WR was flushed. 54 * 55 * VALID: The MR was registered before the QP entered ERROR state. 56 * 57 * When frwr_op_map encounters STALE and VALID MRs, they are recovered 58 * with ib_dereg_mr and then are re-initialized. Beause MR recovery 59 * allocates fresh resources, it is deferred to a workqueue, and the 60 * recovered MRs are placed back on the rb_mws list when recovery is 61 * complete. frwr_op_map allocates another MR for the current RPC while 62 * the broken MR is reset. 63 * 64 * To ensure that frwr_op_map doesn't encounter an MR that is marked 65 * INVALID but that is about to be flushed due to a previous transport 66 * disconnect, the transport connect worker attempts to drain all 67 * pending send queue WRs before the transport is reconnected. 68 */ 69 70 #include "xprt_rdma.h" 71 72 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 73 # define RPCDBG_FACILITY RPCDBG_TRANS 74 #endif 75 76 static struct workqueue_struct *frwr_recovery_wq; 77 78 #define FRWR_RECOVERY_WQ_FLAGS (WQ_UNBOUND | WQ_MEM_RECLAIM) 79 80 int 81 frwr_alloc_recovery_wq(void) 82 { 83 frwr_recovery_wq = alloc_workqueue("frwr_recovery", 84 FRWR_RECOVERY_WQ_FLAGS, 0); 85 return !frwr_recovery_wq ? -ENOMEM : 0; 86 } 87 88 void 89 frwr_destroy_recovery_wq(void) 90 { 91 struct workqueue_struct *wq; 92 93 if (!frwr_recovery_wq) 94 return; 95 96 wq = frwr_recovery_wq; 97 frwr_recovery_wq = NULL; 98 destroy_workqueue(wq); 99 } 100 101 static int 102 __frwr_reset_mr(struct rpcrdma_ia *ia, struct rpcrdma_mw *r) 103 { 104 struct rpcrdma_frmr *f = &r->frmr; 105 int rc; 106 107 rc = ib_dereg_mr(f->fr_mr); 108 if (rc) { 109 pr_warn("rpcrdma: ib_dereg_mr status %d, frwr %p orphaned\n", 110 rc, r); 111 return rc; 112 } 113 114 f->fr_mr = ib_alloc_mr(ia->ri_pd, IB_MR_TYPE_MEM_REG, 115 ia->ri_max_frmr_depth); 116 if (IS_ERR(f->fr_mr)) { 117 pr_warn("rpcrdma: ib_alloc_mr status %ld, frwr %p orphaned\n", 118 PTR_ERR(f->fr_mr), r); 119 return PTR_ERR(f->fr_mr); 120 } 121 122 dprintk("RPC: %s: recovered FRMR %p\n", __func__, r); 123 f->fr_state = FRMR_IS_INVALID; 124 return 0; 125 } 126 127 static void 128 __frwr_reset_and_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw) 129 { 130 struct rpcrdma_ia *ia = &r_xprt->rx_ia; 131 struct rpcrdma_frmr *f = &mw->frmr; 132 int rc; 133 134 rc = __frwr_reset_mr(ia, mw); 135 ib_dma_unmap_sg(ia->ri_device, f->fr_sg, f->fr_nents, f->fr_dir); 136 if (rc) 137 return; 138 139 rpcrdma_put_mw(r_xprt, mw); 140 } 141 142 /* Deferred reset of a single FRMR. Generate a fresh rkey by 143 * replacing the MR. 144 * 145 * There's no recovery if this fails. The FRMR is abandoned, but 146 * remains in rb_all. It will be cleaned up when the transport is 147 * destroyed. 148 */ 149 static void 150 __frwr_recovery_worker(struct work_struct *work) 151 { 152 struct rpcrdma_mw *r = container_of(work, struct rpcrdma_mw, 153 mw_work); 154 155 __frwr_reset_and_unmap(r->mw_xprt, r); 156 return; 157 } 158 159 /* A broken MR was discovered in a context that can't sleep. 160 * Defer recovery to the recovery worker. 161 */ 162 static void 163 __frwr_queue_recovery(struct rpcrdma_mw *r) 164 { 165 INIT_WORK(&r->mw_work, __frwr_recovery_worker); 166 queue_work(frwr_recovery_wq, &r->mw_work); 167 } 168 169 static int 170 __frwr_init(struct rpcrdma_mw *r, struct ib_pd *pd, struct ib_device *device, 171 unsigned int depth) 172 { 173 struct rpcrdma_frmr *f = &r->frmr; 174 int rc; 175 176 f->fr_mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, depth); 177 if (IS_ERR(f->fr_mr)) 178 goto out_mr_err; 179 180 f->fr_sg = kcalloc(depth, sizeof(*f->fr_sg), GFP_KERNEL); 181 if (!f->fr_sg) 182 goto out_list_err; 183 184 sg_init_table(f->fr_sg, depth); 185 186 init_completion(&f->fr_linv_done); 187 188 return 0; 189 190 out_mr_err: 191 rc = PTR_ERR(f->fr_mr); 192 dprintk("RPC: %s: ib_alloc_mr status %i\n", 193 __func__, rc); 194 return rc; 195 196 out_list_err: 197 rc = -ENOMEM; 198 dprintk("RPC: %s: sg allocation failure\n", 199 __func__); 200 ib_dereg_mr(f->fr_mr); 201 return rc; 202 } 203 204 static void 205 __frwr_release(struct rpcrdma_mw *r) 206 { 207 int rc; 208 209 rc = ib_dereg_mr(r->frmr.fr_mr); 210 if (rc) 211 dprintk("RPC: %s: ib_dereg_mr status %i\n", 212 __func__, rc); 213 kfree(r->frmr.fr_sg); 214 } 215 216 static int 217 frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep, 218 struct rpcrdma_create_data_internal *cdata) 219 { 220 int depth, delta; 221 222 ia->ri_max_frmr_depth = 223 min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS, 224 ia->ri_device->attrs.max_fast_reg_page_list_len); 225 dprintk("RPC: %s: device's max FR page list len = %u\n", 226 __func__, ia->ri_max_frmr_depth); 227 228 /* Add room for frmr register and invalidate WRs. 229 * 1. FRMR reg WR for head 230 * 2. FRMR invalidate WR for head 231 * 3. N FRMR reg WRs for pagelist 232 * 4. N FRMR invalidate WRs for pagelist 233 * 5. FRMR reg WR for tail 234 * 6. FRMR invalidate WR for tail 235 * 7. The RDMA_SEND WR 236 */ 237 depth = 7; 238 239 /* Calculate N if the device max FRMR depth is smaller than 240 * RPCRDMA_MAX_DATA_SEGS. 241 */ 242 if (ia->ri_max_frmr_depth < RPCRDMA_MAX_DATA_SEGS) { 243 delta = RPCRDMA_MAX_DATA_SEGS - ia->ri_max_frmr_depth; 244 do { 245 depth += 2; /* FRMR reg + invalidate */ 246 delta -= ia->ri_max_frmr_depth; 247 } while (delta > 0); 248 } 249 250 ep->rep_attr.cap.max_send_wr *= depth; 251 if (ep->rep_attr.cap.max_send_wr > ia->ri_device->attrs.max_qp_wr) { 252 cdata->max_requests = ia->ri_device->attrs.max_qp_wr / depth; 253 if (!cdata->max_requests) 254 return -EINVAL; 255 ep->rep_attr.cap.max_send_wr = cdata->max_requests * 256 depth; 257 } 258 259 rpcrdma_set_max_header_sizes(ia, cdata, max_t(unsigned int, 1, 260 RPCRDMA_MAX_DATA_SEGS / 261 ia->ri_max_frmr_depth)); 262 return 0; 263 } 264 265 /* FRWR mode conveys a list of pages per chunk segment. The 266 * maximum length of that list is the FRWR page list depth. 267 */ 268 static size_t 269 frwr_op_maxpages(struct rpcrdma_xprt *r_xprt) 270 { 271 struct rpcrdma_ia *ia = &r_xprt->rx_ia; 272 273 return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS, 274 RPCRDMA_MAX_HDR_SEGS * ia->ri_max_frmr_depth); 275 } 276 277 static void 278 __frwr_sendcompletion_flush(struct ib_wc *wc, struct rpcrdma_frmr *frmr, 279 const char *wr) 280 { 281 frmr->fr_state = FRMR_IS_STALE; 282 if (wc->status != IB_WC_WR_FLUSH_ERR) 283 pr_err("rpcrdma: %s: %s (%u/0x%x)\n", 284 wr, ib_wc_status_msg(wc->status), 285 wc->status, wc->vendor_err); 286 } 287 288 /** 289 * frwr_wc_fastreg - Invoked by RDMA provider for each polled FastReg WC 290 * @cq: completion queue (ignored) 291 * @wc: completed WR 292 * 293 */ 294 static void 295 frwr_wc_fastreg(struct ib_cq *cq, struct ib_wc *wc) 296 { 297 struct rpcrdma_frmr *frmr; 298 struct ib_cqe *cqe; 299 300 /* WARNING: Only wr_cqe and status are reliable at this point */ 301 if (wc->status != IB_WC_SUCCESS) { 302 cqe = wc->wr_cqe; 303 frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe); 304 __frwr_sendcompletion_flush(wc, frmr, "fastreg"); 305 } 306 } 307 308 /** 309 * frwr_wc_localinv - Invoked by RDMA provider for each polled LocalInv WC 310 * @cq: completion queue (ignored) 311 * @wc: completed WR 312 * 313 */ 314 static void 315 frwr_wc_localinv(struct ib_cq *cq, struct ib_wc *wc) 316 { 317 struct rpcrdma_frmr *frmr; 318 struct ib_cqe *cqe; 319 320 /* WARNING: Only wr_cqe and status are reliable at this point */ 321 if (wc->status != IB_WC_SUCCESS) { 322 cqe = wc->wr_cqe; 323 frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe); 324 __frwr_sendcompletion_flush(wc, frmr, "localinv"); 325 } 326 } 327 328 /** 329 * frwr_wc_localinv - Invoked by RDMA provider for each polled LocalInv WC 330 * @cq: completion queue (ignored) 331 * @wc: completed WR 332 * 333 * Awaken anyone waiting for an MR to finish being fenced. 334 */ 335 static void 336 frwr_wc_localinv_wake(struct ib_cq *cq, struct ib_wc *wc) 337 { 338 struct rpcrdma_frmr *frmr; 339 struct ib_cqe *cqe; 340 341 /* WARNING: Only wr_cqe and status are reliable at this point */ 342 cqe = wc->wr_cqe; 343 frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe); 344 if (wc->status != IB_WC_SUCCESS) 345 __frwr_sendcompletion_flush(wc, frmr, "localinv"); 346 complete_all(&frmr->fr_linv_done); 347 } 348 349 static int 350 frwr_op_init(struct rpcrdma_xprt *r_xprt) 351 { 352 struct rpcrdma_buffer *buf = &r_xprt->rx_buf; 353 struct ib_device *device = r_xprt->rx_ia.ri_device; 354 unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth; 355 struct ib_pd *pd = r_xprt->rx_ia.ri_pd; 356 int i; 357 358 spin_lock_init(&buf->rb_mwlock); 359 INIT_LIST_HEAD(&buf->rb_mws); 360 INIT_LIST_HEAD(&buf->rb_all); 361 362 i = max_t(int, RPCRDMA_MAX_DATA_SEGS / depth, 1); 363 i += 2; /* head + tail */ 364 i *= buf->rb_max_requests; /* one set for each RPC slot */ 365 dprintk("RPC: %s: initalizing %d FRMRs\n", __func__, i); 366 367 while (i--) { 368 struct rpcrdma_mw *r; 369 int rc; 370 371 r = kzalloc(sizeof(*r), GFP_KERNEL); 372 if (!r) 373 return -ENOMEM; 374 375 rc = __frwr_init(r, pd, device, depth); 376 if (rc) { 377 kfree(r); 378 return rc; 379 } 380 381 r->mw_xprt = r_xprt; 382 list_add(&r->mw_list, &buf->rb_mws); 383 list_add(&r->mw_all, &buf->rb_all); 384 } 385 386 return 0; 387 } 388 389 /* Post a FAST_REG Work Request to register a memory region 390 * for remote access via RDMA READ or RDMA WRITE. 391 */ 392 static int 393 frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg, 394 int nsegs, bool writing) 395 { 396 struct rpcrdma_ia *ia = &r_xprt->rx_ia; 397 struct ib_device *device = ia->ri_device; 398 enum dma_data_direction direction = rpcrdma_data_dir(writing); 399 struct rpcrdma_mr_seg *seg1 = seg; 400 struct rpcrdma_mw *mw; 401 struct rpcrdma_frmr *frmr; 402 struct ib_mr *mr; 403 struct ib_reg_wr *reg_wr; 404 struct ib_send_wr *bad_wr; 405 int rc, i, n, dma_nents; 406 u8 key; 407 408 mw = seg1->rl_mw; 409 seg1->rl_mw = NULL; 410 do { 411 if (mw) 412 __frwr_queue_recovery(mw); 413 mw = rpcrdma_get_mw(r_xprt); 414 if (!mw) 415 return -ENOMEM; 416 } while (mw->frmr.fr_state != FRMR_IS_INVALID); 417 frmr = &mw->frmr; 418 frmr->fr_state = FRMR_IS_VALID; 419 mr = frmr->fr_mr; 420 reg_wr = &frmr->fr_regwr; 421 422 if (nsegs > ia->ri_max_frmr_depth) 423 nsegs = ia->ri_max_frmr_depth; 424 425 for (i = 0; i < nsegs;) { 426 if (seg->mr_page) 427 sg_set_page(&frmr->fr_sg[i], 428 seg->mr_page, 429 seg->mr_len, 430 offset_in_page(seg->mr_offset)); 431 else 432 sg_set_buf(&frmr->fr_sg[i], seg->mr_offset, 433 seg->mr_len); 434 435 ++seg; 436 ++i; 437 438 /* Check for holes */ 439 if ((i < nsegs && offset_in_page(seg->mr_offset)) || 440 offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len)) 441 break; 442 } 443 frmr->fr_nents = i; 444 frmr->fr_dir = direction; 445 446 dma_nents = ib_dma_map_sg(device, frmr->fr_sg, frmr->fr_nents, direction); 447 if (!dma_nents) { 448 pr_err("RPC: %s: failed to dma map sg %p sg_nents %u\n", 449 __func__, frmr->fr_sg, frmr->fr_nents); 450 return -ENOMEM; 451 } 452 453 n = ib_map_mr_sg(mr, frmr->fr_sg, frmr->fr_nents, NULL, PAGE_SIZE); 454 if (unlikely(n != frmr->fr_nents)) { 455 pr_err("RPC: %s: failed to map mr %p (%u/%u)\n", 456 __func__, frmr->fr_mr, n, frmr->fr_nents); 457 rc = n < 0 ? n : -EINVAL; 458 goto out_senderr; 459 } 460 461 dprintk("RPC: %s: Using frmr %p to map %u segments (%u bytes)\n", 462 __func__, mw, frmr->fr_nents, mr->length); 463 464 key = (u8)(mr->rkey & 0x000000FF); 465 ib_update_fast_reg_key(mr, ++key); 466 467 reg_wr->wr.next = NULL; 468 reg_wr->wr.opcode = IB_WR_REG_MR; 469 frmr->fr_cqe.done = frwr_wc_fastreg; 470 reg_wr->wr.wr_cqe = &frmr->fr_cqe; 471 reg_wr->wr.num_sge = 0; 472 reg_wr->wr.send_flags = 0; 473 reg_wr->mr = mr; 474 reg_wr->key = mr->rkey; 475 reg_wr->access = writing ? 476 IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE : 477 IB_ACCESS_REMOTE_READ; 478 479 DECR_CQCOUNT(&r_xprt->rx_ep); 480 rc = ib_post_send(ia->ri_id->qp, ®_wr->wr, &bad_wr); 481 if (rc) 482 goto out_senderr; 483 484 seg1->rl_mw = mw; 485 seg1->mr_rkey = mr->rkey; 486 seg1->mr_base = mr->iova; 487 seg1->mr_nsegs = frmr->fr_nents; 488 seg1->mr_len = mr->length; 489 490 return frmr->fr_nents; 491 492 out_senderr: 493 dprintk("RPC: %s: ib_post_send status %i\n", __func__, rc); 494 __frwr_queue_recovery(mw); 495 return rc; 496 } 497 498 static struct ib_send_wr * 499 __frwr_prepare_linv_wr(struct rpcrdma_mr_seg *seg) 500 { 501 struct rpcrdma_mw *mw = seg->rl_mw; 502 struct rpcrdma_frmr *f = &mw->frmr; 503 struct ib_send_wr *invalidate_wr; 504 505 f->fr_state = FRMR_IS_INVALID; 506 invalidate_wr = &f->fr_invwr; 507 508 memset(invalidate_wr, 0, sizeof(*invalidate_wr)); 509 f->fr_cqe.done = frwr_wc_localinv; 510 invalidate_wr->wr_cqe = &f->fr_cqe; 511 invalidate_wr->opcode = IB_WR_LOCAL_INV; 512 invalidate_wr->ex.invalidate_rkey = f->fr_mr->rkey; 513 514 return invalidate_wr; 515 } 516 517 /* Invalidate all memory regions that were registered for "req". 518 * 519 * Sleeps until it is safe for the host CPU to access the 520 * previously mapped memory regions. 521 */ 522 static void 523 frwr_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) 524 { 525 struct ib_send_wr *invalidate_wrs, *pos, *prev, *bad_wr; 526 struct rpcrdma_ia *ia = &r_xprt->rx_ia; 527 struct rpcrdma_mr_seg *seg; 528 unsigned int i, nchunks; 529 struct rpcrdma_frmr *f; 530 struct rpcrdma_mw *mw; 531 int rc; 532 533 dprintk("RPC: %s: req %p\n", __func__, req); 534 535 /* ORDER: Invalidate all of the req's MRs first 536 * 537 * Chain the LOCAL_INV Work Requests and post them with 538 * a single ib_post_send() call. 539 */ 540 invalidate_wrs = pos = prev = NULL; 541 seg = NULL; 542 for (i = 0, nchunks = req->rl_nchunks; nchunks; nchunks--) { 543 seg = &req->rl_segments[i]; 544 545 pos = __frwr_prepare_linv_wr(seg); 546 547 if (!invalidate_wrs) 548 invalidate_wrs = pos; 549 else 550 prev->next = pos; 551 prev = pos; 552 553 i += seg->mr_nsegs; 554 } 555 f = &seg->rl_mw->frmr; 556 557 /* Strong send queue ordering guarantees that when the 558 * last WR in the chain completes, all WRs in the chain 559 * are complete. 560 */ 561 f->fr_invwr.send_flags = IB_SEND_SIGNALED; 562 f->fr_cqe.done = frwr_wc_localinv_wake; 563 reinit_completion(&f->fr_linv_done); 564 INIT_CQCOUNT(&r_xprt->rx_ep); 565 566 /* Transport disconnect drains the receive CQ before it 567 * replaces the QP. The RPC reply handler won't call us 568 * unless ri_id->qp is a valid pointer. 569 */ 570 rc = ib_post_send(ia->ri_id->qp, invalidate_wrs, &bad_wr); 571 if (rc) 572 goto reset_mrs; 573 574 wait_for_completion(&f->fr_linv_done); 575 576 /* ORDER: Now DMA unmap all of the req's MRs, and return 577 * them to the free MW list. 578 */ 579 unmap: 580 for (i = 0, nchunks = req->rl_nchunks; nchunks; nchunks--) { 581 seg = &req->rl_segments[i]; 582 mw = seg->rl_mw; 583 seg->rl_mw = NULL; 584 585 ib_dma_unmap_sg(ia->ri_device, f->fr_sg, f->fr_nents, 586 f->fr_dir); 587 rpcrdma_put_mw(r_xprt, mw); 588 589 i += seg->mr_nsegs; 590 seg->mr_nsegs = 0; 591 } 592 593 req->rl_nchunks = 0; 594 return; 595 596 reset_mrs: 597 pr_warn("%s: ib_post_send failed %i\n", __func__, rc); 598 599 /* Find and reset the MRs in the LOCAL_INV WRs that did not 600 * get posted. This is synchronous, and slow. 601 */ 602 for (i = 0, nchunks = req->rl_nchunks; nchunks; nchunks--) { 603 seg = &req->rl_segments[i]; 604 mw = seg->rl_mw; 605 f = &mw->frmr; 606 607 if (mw->frmr.fr_mr->rkey == bad_wr->ex.invalidate_rkey) { 608 __frwr_reset_mr(ia, mw); 609 bad_wr = bad_wr->next; 610 } 611 612 i += seg->mr_nsegs; 613 } 614 goto unmap; 615 } 616 617 /* Use a slow, safe mechanism to invalidate all memory regions 618 * that were registered for "req". 619 */ 620 static void 621 frwr_op_unmap_safe(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req, 622 bool sync) 623 { 624 struct rpcrdma_mr_seg *seg; 625 struct rpcrdma_mw *mw; 626 unsigned int i; 627 628 for (i = 0; req->rl_nchunks; req->rl_nchunks--) { 629 seg = &req->rl_segments[i]; 630 mw = seg->rl_mw; 631 632 if (sync) 633 __frwr_reset_and_unmap(r_xprt, mw); 634 else 635 __frwr_queue_recovery(mw); 636 637 i += seg->mr_nsegs; 638 seg->mr_nsegs = 0; 639 seg->rl_mw = NULL; 640 } 641 } 642 643 static void 644 frwr_op_destroy(struct rpcrdma_buffer *buf) 645 { 646 struct rpcrdma_mw *r; 647 648 /* Ensure stale MWs for "buf" are no longer in flight */ 649 flush_workqueue(frwr_recovery_wq); 650 651 while (!list_empty(&buf->rb_all)) { 652 r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all); 653 list_del(&r->mw_all); 654 __frwr_release(r); 655 kfree(r); 656 } 657 } 658 659 const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = { 660 .ro_map = frwr_op_map, 661 .ro_unmap_sync = frwr_op_unmap_sync, 662 .ro_unmap_safe = frwr_op_unmap_safe, 663 .ro_open = frwr_op_open, 664 .ro_maxpages = frwr_op_maxpages, 665 .ro_init = frwr_op_init, 666 .ro_destroy = frwr_op_destroy, 667 .ro_displayname = "frwr", 668 }; 669