1 /* 2 * Copyright 2008-2010, Ingo Weinhold, ingo_weinhold@gmx.de. 3 * Distributed under the terms of the MIT License. 4 */ 5 6 // included by vfs.cpp 7 8 9 //#define TRACE_VFS_REQUEST_IO 10 #ifdef TRACE_VFS_REQUEST_IO 11 # define TRACE_RIO(x...) dprintf(x) 12 #else 13 # define TRACE_RIO(x...) do {} while (false) 14 #endif 15 16 17 #include <heap.h> 18 19 20 // #pragma mark - AsyncIOCallback 21 22 23 AsyncIOCallback::~AsyncIOCallback() 24 { 25 } 26 27 28 /* static */ status_t 29 AsyncIOCallback::IORequestCallback(void* data, io_request* request, 30 status_t status, bool partialTransfer, generic_size_t transferEndOffset) 31 { 32 ((AsyncIOCallback*)data)->IOFinished(status, partialTransfer, 33 transferEndOffset); 34 return B_OK; 35 } 36 37 38 // #pragma mark - StackableAsyncIOCallback 39 40 41 StackableAsyncIOCallback::StackableAsyncIOCallback(AsyncIOCallback* next) 42 : 43 fNextCallback(next) 44 { 45 } 46 47 48 // #pragma mark - 49 50 51 struct iterative_io_cookie { 52 struct vnode* vnode; 53 file_descriptor* descriptor; 54 iterative_io_get_vecs get_vecs; 55 iterative_io_finished finished; 56 void* cookie; 57 off_t request_offset; 58 io_request_finished_callback next_finished_callback; 59 void* next_finished_cookie; 60 }; 61 62 63 class DoIO { 64 public: 65 DoIO(bool write) 66 : 67 fWrite(write) 68 { 69 } 70 71 virtual ~DoIO() 72 { 73 } 74 75 virtual status_t IO(off_t offset, void* buffer, size_t* length) = 0; 76 77 protected: 78 bool fWrite; 79 }; 80 81 82 class CallbackIO : public DoIO { 83 public: 84 CallbackIO(bool write, 85 status_t (*doIO)(void* cookie, off_t offset, void* buffer, 86 size_t* length), 87 void* cookie) 88 : 89 DoIO(write), 90 fDoIO(doIO), 91 fCookie(cookie) 92 { 93 } 94 95 virtual status_t IO(off_t offset, void* buffer, size_t* length) 96 { 97 return fDoIO(fCookie, offset, buffer, length); 98 } 99 100 private: 101 status_t (*fDoIO)(void*, off_t, void*, size_t*); 102 void* fCookie; 103 }; 104 105 106 class VnodeIO : public DoIO { 107 public: 108 VnodeIO(bool write, struct vnode* vnode, void* cookie) 109 : 110 DoIO(write), 111 fVnode(vnode), 112 fCookie(cookie) 113 { 114 } 115 116 virtual status_t IO(off_t offset, void* buffer, size_t* length) 117 { 118 iovec vec; 119 vec.iov_base = buffer; 120 vec.iov_len = *length; 121 122 if (fWrite) { 123 return FS_CALL(fVnode, write_pages, fCookie, offset, &vec, 1, 124 length); 125 } 126 127 return FS_CALL(fVnode, read_pages, fCookie, offset, &vec, 1, length); 128 } 129 130 private: 131 struct vnode* fVnode; 132 void* fCookie; 133 }; 134 135 136 static status_t 137 do_iterative_fd_io_iterate(void* _cookie, io_request* request, 138 bool* _partialTransfer) 139 { 140 TRACE_RIO("[%ld] do_iterative_fd_io_iterate(request: %p)\n", 141 find_thread(NULL), request); 142 143 static const int32 kMaxSubRequests = 8; 144 145 iterative_io_cookie* cookie = (iterative_io_cookie*)_cookie; 146 147 request->DeleteSubRequests(); 148 149 off_t requestOffset = cookie->request_offset; 150 size_t requestLength = request->Length() 151 - (requestOffset - request->Offset()); 152 153 // get the next file vecs 154 file_io_vec vecs[kMaxSubRequests]; 155 uint32 vecCount = kMaxSubRequests; 156 status_t error = cookie->get_vecs(cookie->cookie, request, requestOffset, 157 requestLength, vecs, &vecCount); 158 if (error != B_OK && error != B_BUFFER_OVERFLOW) 159 return error; 160 if (vecCount == 0) { 161 *_partialTransfer = true; 162 return B_OK; 163 } 164 TRACE_RIO("[%ld] got %lu file vecs\n", find_thread(NULL), vecCount); 165 166 // create subrequests for the file vecs we've got 167 int32 subRequestCount = 0; 168 for (uint32 i = 0; i < vecCount && subRequestCount < kMaxSubRequests; i++) { 169 off_t vecOffset = vecs[i].offset; 170 off_t vecLength = min_c(vecs[i].length, requestLength); 171 TRACE_RIO("[%ld] vec %lu offset: %lld, length: %lld\n", 172 find_thread(NULL), i, vecOffset, vecLength); 173 174 while (vecLength > 0 && subRequestCount < kMaxSubRequests) { 175 TRACE_RIO("[%ld] creating subrequest: offset: %lld, length: " 176 "%lld\n", find_thread(NULL), vecOffset, vecLength); 177 IORequest* subRequest; 178 error = request->CreateSubRequest(requestOffset, vecOffset, 179 vecLength, subRequest); 180 if (error != B_OK) 181 break; 182 183 subRequestCount++; 184 185 size_t lengthProcessed = subRequest->Length(); 186 vecOffset += lengthProcessed; 187 vecLength -= lengthProcessed; 188 requestOffset += lengthProcessed; 189 requestLength -= lengthProcessed; 190 } 191 } 192 193 // Only if we couldn't create any subrequests, we fail. 194 if (error != B_OK && subRequestCount == 0) 195 return error; 196 197 // Reset the error code for the loop below 198 error = B_OK; 199 200 request->Advance(requestOffset - cookie->request_offset); 201 cookie->request_offset = requestOffset; 202 203 // Schedule the subrequests. 204 IORequest* nextSubRequest = request->FirstSubRequest(); 205 while (nextSubRequest != NULL) { 206 IORequest* subRequest = nextSubRequest; 207 nextSubRequest = request->NextSubRequest(subRequest); 208 209 if (error == B_OK) { 210 TRACE_RIO("[%ld] scheduling subrequest: %p\n", find_thread(NULL), 211 subRequest); 212 error = vfs_vnode_io(cookie->vnode, cookie->descriptor->cookie, 213 subRequest); 214 } else { 215 // Once scheduling a subrequest failed, we cancel all subsequent 216 // subrequests. 217 subRequest->SetStatusAndNotify(B_CANCELED); 218 } 219 } 220 221 // TODO: Cancel the subrequests that were scheduled successfully. 222 223 return B_OK; 224 } 225 226 227 static status_t 228 do_iterative_fd_io_finish(void* _cookie, io_request* request, status_t status, 229 bool partialTransfer, generic_size_t transferEndOffset) 230 { 231 iterative_io_cookie* cookie = (iterative_io_cookie*)_cookie; 232 233 if (cookie->finished != NULL) { 234 cookie->finished(cookie->cookie, request, status, partialTransfer, 235 transferEndOffset); 236 } 237 238 put_fd(cookie->descriptor); 239 240 if (cookie->next_finished_callback != NULL) { 241 cookie->next_finished_callback(cookie->next_finished_cookie, request, 242 status, partialTransfer, transferEndOffset); 243 } 244 245 delete cookie; 246 247 return B_OK; 248 } 249 250 251 static status_t 252 do_synchronous_iterative_vnode_io(struct vnode* vnode, void* openCookie, 253 io_request* request, iterative_io_get_vecs getVecs, 254 iterative_io_finished finished, void* cookie) 255 { 256 IOBuffer* buffer = request->Buffer(); 257 VnodeIO io(request->IsWrite(), vnode, openCookie); 258 259 iovec vector; 260 void* virtualVecCookie = NULL; 261 off_t offset = request->Offset(); 262 generic_size_t length = request->Length(); 263 264 status_t error = B_OK; 265 266 for (; error == B_OK && length > 0 267 && buffer->GetNextVirtualVec(virtualVecCookie, vector) == B_OK;) { 268 uint8* vecBase = (uint8*)vector.iov_base; 269 generic_size_t vecLength = min_c(vector.iov_len, length); 270 271 while (error == B_OK && vecLength > 0) { 272 file_io_vec fileVecs[8]; 273 uint32 fileVecCount = 8; 274 error = getVecs(cookie, request, offset, vecLength, fileVecs, 275 &fileVecCount); 276 if (error != B_OK || fileVecCount == 0) 277 break; 278 279 for (uint32 i = 0; i < fileVecCount; i++) { 280 const file_io_vec& fileVec = fileVecs[i]; 281 size_t toTransfer = min_c(fileVec.length, (off_t)length); 282 size_t transferred = toTransfer; 283 error = io.IO(fileVec.offset, vecBase, &transferred); 284 if (error != B_OK) 285 break; 286 287 offset += transferred; 288 length -= transferred; 289 vecBase += transferred; 290 vecLength -= transferred; 291 292 if (transferred != toTransfer) 293 break; 294 } 295 } 296 } 297 298 buffer->FreeVirtualVecCookie(virtualVecCookie); 299 300 bool partial = length > 0; 301 size_t bytesTransferred = request->Length() - length; 302 request->SetTransferredBytes(partial, bytesTransferred); 303 finished(cookie, request, error, partial, bytesTransferred); 304 request->SetStatusAndNotify(error); 305 return error; 306 } 307 308 309 static status_t 310 synchronous_io(io_request* request, DoIO& io) 311 { 312 TRACE_RIO("[%" B_PRId32 "] synchronous_io(request: %p (offset: %" B_PRIdOFF 313 ", length: %" B_PRIuGENADDR "))\n", find_thread(NULL), request, 314 request->Offset(), request->Length()); 315 316 IOBuffer* buffer = request->Buffer(); 317 318 iovec vector; 319 void* virtualVecCookie = NULL; 320 off_t offset = request->Offset(); 321 generic_size_t length = request->Length(); 322 323 for (; length > 0 324 && buffer->GetNextVirtualVec(virtualVecCookie, vector) == B_OK;) { 325 void* vecBase = (void*)(addr_t)vector.iov_base; 326 size_t vecLength = min_c(vector.iov_len, length); 327 328 TRACE_RIO("[%ld] I/O: offset: %lld, vecBase: %p, length: %lu\n", 329 find_thread(NULL), offset, vecBase, vecLength); 330 331 size_t transferred = vecLength; 332 status_t error = io.IO(offset, vecBase, &transferred); 333 if (error != B_OK) { 334 TRACE_RIO("[%ld] I/O failed: %#lx\n", find_thread(NULL), error); 335 buffer->FreeVirtualVecCookie(virtualVecCookie); 336 request->SetStatusAndNotify(error); 337 return error; 338 } 339 340 offset += transferred; 341 length -= transferred; 342 343 if (transferred != vecLength) 344 break; 345 } 346 347 TRACE_RIO("[%ld] synchronous_io() succeeded\n", find_thread(NULL)); 348 349 buffer->FreeVirtualVecCookie(virtualVecCookie); 350 request->SetTransferredBytes(length > 0, request->Length() - length); 351 request->SetStatusAndNotify(B_OK); 352 return B_OK; 353 } 354 355 356 // #pragma mark - kernel private API 357 358 359 status_t 360 vfs_vnode_io(struct vnode* vnode, void* cookie, io_request* request) 361 { 362 status_t result = B_ERROR; 363 if (!HAS_FS_CALL(vnode, io) 364 || (result = FS_CALL(vnode, io, cookie, request)) == B_UNSUPPORTED) { 365 // no io() call -- fall back to synchronous I/O 366 VnodeIO io(request->IsWrite(), vnode, cookie); 367 return synchronous_io(request, io); 368 } 369 370 return result; 371 } 372 373 374 status_t 375 vfs_synchronous_io(io_request* request, 376 status_t (*doIO)(void* cookie, off_t offset, void* buffer, size_t* length), 377 void* cookie) 378 { 379 CallbackIO io(request->IsWrite(), doIO, cookie); 380 return synchronous_io(request, io); 381 } 382 383 384 status_t 385 vfs_asynchronous_read_pages(struct vnode* vnode, void* cookie, off_t pos, 386 const generic_io_vec* vecs, size_t count, generic_size_t numBytes, 387 uint32 flags, AsyncIOCallback* callback) 388 { 389 IORequest* request = IORequest::Create((flags & B_VIP_IO_REQUEST) != 0); 390 if (request == NULL) { 391 callback->IOFinished(B_NO_MEMORY, true, 0); 392 return B_NO_MEMORY; 393 } 394 395 status_t status = request->Init(pos, vecs, count, numBytes, false, 396 flags | B_DELETE_IO_REQUEST); 397 if (status != B_OK) { 398 delete request; 399 callback->IOFinished(status, true, 0); 400 return status; 401 } 402 403 request->SetFinishedCallback(&AsyncIOCallback::IORequestCallback, 404 callback); 405 406 return vfs_vnode_io(vnode, cookie, request); 407 } 408 409 410 status_t 411 vfs_asynchronous_write_pages(struct vnode* vnode, void* cookie, off_t pos, 412 const generic_io_vec* vecs, size_t count, generic_size_t numBytes, 413 uint32 flags, AsyncIOCallback* callback) 414 { 415 IORequest* request = IORequest::Create((flags & B_VIP_IO_REQUEST) != 0); 416 if (request == NULL) { 417 callback->IOFinished(B_NO_MEMORY, true, 0); 418 return B_NO_MEMORY; 419 } 420 421 status_t status = request->Init(pos, vecs, count, numBytes, true, 422 flags | B_DELETE_IO_REQUEST); 423 if (status != B_OK) { 424 delete request; 425 callback->IOFinished(status, true, 0); 426 return status; 427 } 428 429 request->SetFinishedCallback(&AsyncIOCallback::IORequestCallback, 430 callback); 431 432 return vfs_vnode_io(vnode, cookie, request); 433 } 434 435 436 // #pragma mark - public API 437 438 439 status_t 440 do_fd_io(int fd, io_request* request) 441 { 442 struct vnode* vnode; 443 file_descriptor* descriptor = get_fd_and_vnode(fd, &vnode, true); 444 if (descriptor == NULL) { 445 request->SetStatusAndNotify(B_FILE_ERROR); 446 return B_FILE_ERROR; 447 } 448 449 CObjectDeleter<file_descriptor> descriptorPutter(descriptor, put_fd); 450 451 return vfs_vnode_io(vnode, descriptor->cookie, request); 452 } 453 454 455 status_t 456 do_iterative_fd_io(int fd, io_request* request, iterative_io_get_vecs getVecs, 457 iterative_io_finished finished, void* cookie) 458 { 459 TRACE_RIO("[%" B_PRId32 "] do_iterative_fd_io(fd: %d, request: %p " 460 "(offset: %" B_PRIdOFF ", length: %" B_PRIuGENADDR "))\n", 461 find_thread(NULL), fd, request, request->Offset(), request->Length()); 462 463 struct vnode* vnode; 464 file_descriptor* descriptor = get_fd_and_vnode(fd, &vnode, true); 465 if (descriptor == NULL) { 466 finished(cookie, request, B_FILE_ERROR, true, 0); 467 request->SetStatusAndNotify(B_FILE_ERROR); 468 return B_FILE_ERROR; 469 } 470 471 CObjectDeleter<file_descriptor> descriptorPutter(descriptor, put_fd); 472 473 if (!HAS_FS_CALL(vnode, io)) { 474 // no io() call -- fall back to synchronous I/O 475 return do_synchronous_iterative_vnode_io(vnode, descriptor->cookie, 476 request, getVecs, finished, cookie); 477 } 478 479 iterative_io_cookie* iterationCookie 480 = (request->Flags() & B_VIP_IO_REQUEST) != 0 481 ? new(malloc_flags(HEAP_PRIORITY_VIP)) iterative_io_cookie 482 : new(std::nothrow) iterative_io_cookie; 483 if (iterationCookie == NULL) { 484 // no memory -- fall back to synchronous I/O 485 return do_synchronous_iterative_vnode_io(vnode, descriptor->cookie, 486 request, getVecs, finished, cookie); 487 } 488 489 iterationCookie->vnode = vnode; 490 iterationCookie->descriptor = descriptor; 491 iterationCookie->get_vecs = getVecs; 492 iterationCookie->finished = finished; 493 iterationCookie->cookie = cookie; 494 iterationCookie->request_offset = request->Offset(); 495 iterationCookie->next_finished_callback = request->FinishedCallback( 496 &iterationCookie->next_finished_cookie); 497 498 request->SetFinishedCallback(&do_iterative_fd_io_finish, iterationCookie); 499 request->SetIterationCallback(&do_iterative_fd_io_iterate, iterationCookie); 500 501 descriptorPutter.Detach(); 502 // From now on the descriptor is put by our finish callback. 503 504 bool partialTransfer = false; 505 status_t error = do_iterative_fd_io_iterate(iterationCookie, request, 506 &partialTransfer); 507 if (error != B_OK || partialTransfer) { 508 if (partialTransfer) { 509 request->SetTransferredBytes(partialTransfer, 510 request->TransferredBytes()); 511 } 512 513 request->SetStatusAndNotify(error); 514 return error; 515 } 516 517 return B_OK; 518 } 519