1/* 2 * GPL HEADER START 3 * 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 only, 8 * as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but 11 * WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License version 2 for more details (a copy is included 14 * in the LICENSE file that accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License 17 * version 2 along with this program; If not, see 18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf 19 * 20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 21 * CA 95054 USA or visit www.sun.com if you need additional information or 22 * have any questions. 23 * 24 * GPL HEADER END 25 */ 26/* 27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. 28 * Use is subject to license terms. 29 * 30 * Copyright (c) 2011, 2012, Intel Corporation. 31 */ 32/* 33 * This file is part of Lustre, http://www.lustre.org/ 34 * Lustre is a trademark of Sun Microsystems, Inc. 35 * 36 * Implementation of cl_page for VVP layer. 37 * 38 * Author: Nikita Danilov <nikita.danilov@sun.com> 39 * Author: Jinshan Xiong <jinshan.xiong@whamcloud.com> 40 */ 41 42#define DEBUG_SUBSYSTEM S_LLITE 43 44 45#include "../include/obd.h" 46#include "../include/lustre_lite.h" 47 48#include "vvp_internal.h" 49 50/***************************************************************************** 51 * 52 * Page operations. 53 * 54 */ 55 56static void vvp_page_fini_common(struct ccc_page *cp) 57{ 58 struct page *vmpage = cp->cpg_page; 59 60 LASSERT(vmpage != NULL); 61 page_cache_release(vmpage); 62} 63 64static void vvp_page_fini(const struct lu_env *env, 65 struct cl_page_slice *slice) 66{ 67 struct ccc_page *cp = cl2ccc_page(slice); 68 struct page *vmpage = cp->cpg_page; 69 70 /* 71 * vmpage->private was already cleared when page was moved into 72 * VPG_FREEING state. 73 */ 74 LASSERT((struct cl_page *)vmpage->private != slice->cpl_page); 75 vvp_page_fini_common(cp); 76} 77 78static int vvp_page_own(const struct lu_env *env, 79 const struct cl_page_slice *slice, struct cl_io *io, 80 int nonblock) 81{ 82 struct ccc_page *vpg = cl2ccc_page(slice); 83 struct page *vmpage = vpg->cpg_page; 84 85 LASSERT(vmpage != NULL); 86 if (nonblock) { 87 if (!trylock_page(vmpage)) 88 return -EAGAIN; 89 90 if (unlikely(PageWriteback(vmpage))) { 91 unlock_page(vmpage); 92 return -EAGAIN; 93 } 94 95 return 0; 96 } 97 98 lock_page(vmpage); 99 wait_on_page_writeback(vmpage); 100 return 0; 101} 102 103static void vvp_page_assume(const struct lu_env *env, 104 const struct cl_page_slice *slice, 105 struct cl_io *unused) 106{ 107 struct page *vmpage = cl2vm_page(slice); 108 109 LASSERT(vmpage != NULL); 110 LASSERT(PageLocked(vmpage)); 111 wait_on_page_writeback(vmpage); 112} 113 114static void vvp_page_unassume(const struct lu_env *env, 115 const struct cl_page_slice *slice, 116 struct cl_io *unused) 117{ 118 struct page *vmpage = cl2vm_page(slice); 119 120 LASSERT(vmpage != NULL); 121 LASSERT(PageLocked(vmpage)); 122} 123 124static void vvp_page_disown(const struct lu_env *env, 125 const struct cl_page_slice *slice, struct cl_io *io) 126{ 127 struct page *vmpage = cl2vm_page(slice); 128 129 LASSERT(vmpage != NULL); 130 LASSERT(PageLocked(vmpage)); 131 132 unlock_page(cl2vm_page(slice)); 133} 134 135static void vvp_page_discard(const struct lu_env *env, 136 const struct cl_page_slice *slice, 137 struct cl_io *unused) 138{ 139 struct page *vmpage = cl2vm_page(slice); 140 struct address_space *mapping; 141 struct ccc_page *cpg = cl2ccc_page(slice); 142 143 LASSERT(vmpage != NULL); 144 LASSERT(PageLocked(vmpage)); 145 146 mapping = vmpage->mapping; 147 148 if (cpg->cpg_defer_uptodate && !cpg->cpg_ra_used) 149 ll_ra_stats_inc(mapping, RA_STAT_DISCARDED); 150 151 /* 152 * truncate_complete_page() calls 153 * a_ops->invalidatepage()->cl_page_delete()->vvp_page_delete(). 154 */ 155 truncate_complete_page(mapping, vmpage); 156} 157 158static int vvp_page_unmap(const struct lu_env *env, 159 const struct cl_page_slice *slice, 160 struct cl_io *unused) 161{ 162 struct page *vmpage = cl2vm_page(slice); 163 __u64 offset; 164 165 LASSERT(vmpage != NULL); 166 LASSERT(PageLocked(vmpage)); 167 168 offset = vmpage->index << PAGE_CACHE_SHIFT; 169 170 /* 171 * XXX is it safe to call this with the page lock held? 172 */ 173 ll_teardown_mmaps(vmpage->mapping, offset, offset + PAGE_CACHE_SIZE); 174 return 0; 175} 176 177static void vvp_page_delete(const struct lu_env *env, 178 const struct cl_page_slice *slice) 179{ 180 struct page *vmpage = cl2vm_page(slice); 181 struct inode *inode = vmpage->mapping->host; 182 struct cl_object *obj = slice->cpl_obj; 183 184 LASSERT(PageLocked(vmpage)); 185 LASSERT((struct cl_page *)vmpage->private == slice->cpl_page); 186 LASSERT(inode == ccc_object_inode(obj)); 187 188 vvp_write_complete(cl2ccc(obj), cl2ccc_page(slice)); 189 ClearPagePrivate(vmpage); 190 vmpage->private = 0; 191 /* 192 * Reference from vmpage to cl_page is removed, but the reference back 193 * is still here. It is removed later in vvp_page_fini(). 194 */ 195} 196 197static void vvp_page_export(const struct lu_env *env, 198 const struct cl_page_slice *slice, 199 int uptodate) 200{ 201 struct page *vmpage = cl2vm_page(slice); 202 203 LASSERT(vmpage != NULL); 204 LASSERT(PageLocked(vmpage)); 205 if (uptodate) 206 SetPageUptodate(vmpage); 207 else 208 ClearPageUptodate(vmpage); 209} 210 211static int vvp_page_is_vmlocked(const struct lu_env *env, 212 const struct cl_page_slice *slice) 213{ 214 return PageLocked(cl2vm_page(slice)) ? -EBUSY : -ENODATA; 215} 216 217static int vvp_page_prep_read(const struct lu_env *env, 218 const struct cl_page_slice *slice, 219 struct cl_io *unused) 220{ 221 /* Skip the page already marked as PG_uptodate. */ 222 return PageUptodate(cl2vm_page(slice)) ? -EALREADY : 0; 223} 224 225static int vvp_page_prep_write(const struct lu_env *env, 226 const struct cl_page_slice *slice, 227 struct cl_io *unused) 228{ 229 struct page *vmpage = cl2vm_page(slice); 230 231 LASSERT(PageLocked(vmpage)); 232 LASSERT(!PageDirty(vmpage)); 233 234 set_page_writeback(vmpage); 235 vvp_write_pending(cl2ccc(slice->cpl_obj), cl2ccc_page(slice)); 236 237 return 0; 238} 239 240/** 241 * Handles page transfer errors at VM level. 242 * 243 * This takes inode as a separate argument, because inode on which error is to 244 * be set can be different from \a vmpage inode in case of direct-io. 245 */ 246static void vvp_vmpage_error(struct inode *inode, struct page *vmpage, int ioret) 247{ 248 struct ccc_object *obj = cl_inode2ccc(inode); 249 250 if (ioret == 0) { 251 ClearPageError(vmpage); 252 obj->cob_discard_page_warned = 0; 253 } else { 254 SetPageError(vmpage); 255 if (ioret == -ENOSPC) 256 set_bit(AS_ENOSPC, &inode->i_mapping->flags); 257 else 258 set_bit(AS_EIO, &inode->i_mapping->flags); 259 260 if ((ioret == -ESHUTDOWN || ioret == -EINTR) && 261 obj->cob_discard_page_warned == 0) { 262 obj->cob_discard_page_warned = 1; 263 ll_dirty_page_discard_warn(vmpage, ioret); 264 } 265 } 266} 267 268static void vvp_page_completion_read(const struct lu_env *env, 269 const struct cl_page_slice *slice, 270 int ioret) 271{ 272 struct ccc_page *cp = cl2ccc_page(slice); 273 struct page *vmpage = cp->cpg_page; 274 struct cl_page *page = cl_page_top(slice->cpl_page); 275 struct inode *inode = ccc_object_inode(page->cp_obj); 276 277 LASSERT(PageLocked(vmpage)); 278 CL_PAGE_HEADER(D_PAGE, env, page, "completing READ with %d\n", ioret); 279 280 if (cp->cpg_defer_uptodate) 281 ll_ra_count_put(ll_i2sbi(inode), 1); 282 283 if (ioret == 0) { 284 if (!cp->cpg_defer_uptodate) 285 cl_page_export(env, page, 1); 286 } else 287 cp->cpg_defer_uptodate = 0; 288 289 if (page->cp_sync_io == NULL) 290 unlock_page(vmpage); 291} 292 293static void vvp_page_completion_write(const struct lu_env *env, 294 const struct cl_page_slice *slice, 295 int ioret) 296{ 297 struct ccc_page *cp = cl2ccc_page(slice); 298 struct cl_page *pg = slice->cpl_page; 299 struct page *vmpage = cp->cpg_page; 300 301 LASSERT(ergo(pg->cp_sync_io != NULL, PageLocked(vmpage))); 302 LASSERT(PageWriteback(vmpage)); 303 304 CL_PAGE_HEADER(D_PAGE, env, pg, "completing WRITE with %d\n", ioret); 305 306 /* 307 * TODO: Actually it makes sense to add the page into oap pending 308 * list again and so that we don't need to take the page out from 309 * SoM write pending list, if we just meet a recoverable error, 310 * -ENOMEM, etc. 311 * To implement this, we just need to return a non zero value in 312 * ->cpo_completion method. The underlying transfer should be notified 313 * and then re-add the page into pending transfer queue. -jay 314 */ 315 316 cp->cpg_write_queued = 0; 317 vvp_write_complete(cl2ccc(slice->cpl_obj), cp); 318 319 /* 320 * Only mark the page error only when it's an async write because 321 * applications won't wait for IO to finish. 322 */ 323 if (pg->cp_sync_io == NULL) 324 vvp_vmpage_error(ccc_object_inode(pg->cp_obj), vmpage, ioret); 325 326 end_page_writeback(vmpage); 327} 328 329/** 330 * Implements cl_page_operations::cpo_make_ready() method. 331 * 332 * This is called to yank a page from the transfer cache and to send it out as 333 * a part of transfer. This function try-locks the page. If try-lock failed, 334 * page is owned by some concurrent IO, and should be skipped (this is bad, 335 * but hopefully rare situation, as it usually results in transfer being 336 * shorter than possible). 337 * 338 * \retval 0 success, page can be placed into transfer 339 * 340 * \retval -EAGAIN page is either used by concurrent IO has been 341 * truncated. Skip it. 342 */ 343static int vvp_page_make_ready(const struct lu_env *env, 344 const struct cl_page_slice *slice) 345{ 346 struct page *vmpage = cl2vm_page(slice); 347 struct cl_page *pg = slice->cpl_page; 348 int result = 0; 349 350 lock_page(vmpage); 351 if (clear_page_dirty_for_io(vmpage)) { 352 LASSERT(pg->cp_state == CPS_CACHED); 353 /* This actually clears the dirty bit in the radix 354 * tree. */ 355 set_page_writeback(vmpage); 356 vvp_write_pending(cl2ccc(slice->cpl_obj), 357 cl2ccc_page(slice)); 358 CL_PAGE_HEADER(D_PAGE, env, pg, "readied\n"); 359 } else if (pg->cp_state == CPS_PAGEOUT) { 360 /* is it possible for osc_flush_async_page() to already 361 * make it ready? */ 362 result = -EALREADY; 363 } else { 364 CL_PAGE_DEBUG(D_ERROR, env, pg, "Unexpecting page state %d.\n", 365 pg->cp_state); 366 LBUG(); 367 } 368 unlock_page(vmpage); 369 return result; 370} 371 372static int vvp_page_print(const struct lu_env *env, 373 const struct cl_page_slice *slice, 374 void *cookie, lu_printer_t printer) 375{ 376 struct ccc_page *vp = cl2ccc_page(slice); 377 struct page *vmpage = vp->cpg_page; 378 379 (*printer)(env, cookie, LUSTRE_VVP_NAME"-page@%p(%d:%d:%d) " 380 "vm@%p ", 381 vp, vp->cpg_defer_uptodate, vp->cpg_ra_used, 382 vp->cpg_write_queued, vmpage); 383 if (vmpage != NULL) { 384 (*printer)(env, cookie, "%lx %d:%d %lx %lu %slru", 385 (long)vmpage->flags, page_count(vmpage), 386 page_mapcount(vmpage), vmpage->private, 387 page_index(vmpage), 388 list_empty(&vmpage->lru) ? "not-" : ""); 389 } 390 (*printer)(env, cookie, "\n"); 391 return 0; 392} 393 394static const struct cl_page_operations vvp_page_ops = { 395 .cpo_own = vvp_page_own, 396 .cpo_assume = vvp_page_assume, 397 .cpo_unassume = vvp_page_unassume, 398 .cpo_disown = vvp_page_disown, 399 .cpo_vmpage = ccc_page_vmpage, 400 .cpo_discard = vvp_page_discard, 401 .cpo_delete = vvp_page_delete, 402 .cpo_unmap = vvp_page_unmap, 403 .cpo_export = vvp_page_export, 404 .cpo_is_vmlocked = vvp_page_is_vmlocked, 405 .cpo_fini = vvp_page_fini, 406 .cpo_print = vvp_page_print, 407 .cpo_is_under_lock = ccc_page_is_under_lock, 408 .io = { 409 [CRT_READ] = { 410 .cpo_prep = vvp_page_prep_read, 411 .cpo_completion = vvp_page_completion_read, 412 .cpo_make_ready = ccc_fail, 413 }, 414 [CRT_WRITE] = { 415 .cpo_prep = vvp_page_prep_write, 416 .cpo_completion = vvp_page_completion_write, 417 .cpo_make_ready = vvp_page_make_ready, 418 } 419 } 420}; 421 422static void vvp_transient_page_verify(const struct cl_page *page) 423{ 424 struct inode *inode = ccc_object_inode(page->cp_obj); 425 426 LASSERT(!mutex_trylock(&inode->i_mutex)); 427} 428 429static int vvp_transient_page_own(const struct lu_env *env, 430 const struct cl_page_slice *slice, 431 struct cl_io *unused, int nonblock) 432{ 433 vvp_transient_page_verify(slice->cpl_page); 434 return 0; 435} 436 437static void vvp_transient_page_assume(const struct lu_env *env, 438 const struct cl_page_slice *slice, 439 struct cl_io *unused) 440{ 441 vvp_transient_page_verify(slice->cpl_page); 442} 443 444static void vvp_transient_page_unassume(const struct lu_env *env, 445 const struct cl_page_slice *slice, 446 struct cl_io *unused) 447{ 448 vvp_transient_page_verify(slice->cpl_page); 449} 450 451static void vvp_transient_page_disown(const struct lu_env *env, 452 const struct cl_page_slice *slice, 453 struct cl_io *unused) 454{ 455 vvp_transient_page_verify(slice->cpl_page); 456} 457 458static void vvp_transient_page_discard(const struct lu_env *env, 459 const struct cl_page_slice *slice, 460 struct cl_io *unused) 461{ 462 struct cl_page *page = slice->cpl_page; 463 464 vvp_transient_page_verify(slice->cpl_page); 465 466 /* 467 * For transient pages, remove it from the radix tree. 468 */ 469 cl_page_delete(env, page); 470} 471 472static int vvp_transient_page_is_vmlocked(const struct lu_env *env, 473 const struct cl_page_slice *slice) 474{ 475 struct inode *inode = ccc_object_inode(slice->cpl_obj); 476 int locked; 477 478 locked = !mutex_trylock(&inode->i_mutex); 479 if (!locked) 480 mutex_unlock(&inode->i_mutex); 481 return locked ? -EBUSY : -ENODATA; 482} 483 484static void 485vvp_transient_page_completion(const struct lu_env *env, 486 const struct cl_page_slice *slice, 487 int ioret) 488{ 489 vvp_transient_page_verify(slice->cpl_page); 490} 491 492static void vvp_transient_page_fini(const struct lu_env *env, 493 struct cl_page_slice *slice) 494{ 495 struct ccc_page *cp = cl2ccc_page(slice); 496 struct cl_page *clp = slice->cpl_page; 497 struct ccc_object *clobj = cl2ccc(clp->cp_obj); 498 499 vvp_page_fini_common(cp); 500 LASSERT(!mutex_trylock(&clobj->cob_inode->i_mutex)); 501 clobj->cob_transient_pages--; 502} 503 504static const struct cl_page_operations vvp_transient_page_ops = { 505 .cpo_own = vvp_transient_page_own, 506 .cpo_assume = vvp_transient_page_assume, 507 .cpo_unassume = vvp_transient_page_unassume, 508 .cpo_disown = vvp_transient_page_disown, 509 .cpo_discard = vvp_transient_page_discard, 510 .cpo_vmpage = ccc_page_vmpage, 511 .cpo_fini = vvp_transient_page_fini, 512 .cpo_is_vmlocked = vvp_transient_page_is_vmlocked, 513 .cpo_print = vvp_page_print, 514 .cpo_is_under_lock = ccc_page_is_under_lock, 515 .io = { 516 [CRT_READ] = { 517 .cpo_prep = ccc_transient_page_prep, 518 .cpo_completion = vvp_transient_page_completion, 519 }, 520 [CRT_WRITE] = { 521 .cpo_prep = ccc_transient_page_prep, 522 .cpo_completion = vvp_transient_page_completion, 523 } 524 } 525}; 526 527int vvp_page_init(const struct lu_env *env, struct cl_object *obj, 528 struct cl_page *page, struct page *vmpage) 529{ 530 struct ccc_page *cpg = cl_object_page_slice(obj, page); 531 532 CLOBINVRNT(env, obj, ccc_object_invariant(obj)); 533 534 cpg->cpg_page = vmpage; 535 page_cache_get(vmpage); 536 537 INIT_LIST_HEAD(&cpg->cpg_pending_linkage); 538 if (page->cp_type == CPT_CACHEABLE) { 539 SetPagePrivate(vmpage); 540 vmpage->private = (unsigned long)page; 541 cl_page_slice_add(page, &cpg->cpg_cl, obj, 542 &vvp_page_ops); 543 } else { 544 struct ccc_object *clobj = cl2ccc(obj); 545 546 LASSERT(!mutex_trylock(&clobj->cob_inode->i_mutex)); 547 cl_page_slice_add(page, &cpg->cpg_cl, obj, 548 &vvp_transient_page_ops); 549 clobj->cob_transient_pages++; 550 } 551 return 0; 552} 553