2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
10 /* Copyright (C) 1994 Cazamar Systems, Inc. */
12 #include <afs/param.h>
23 #include "cm_memmap.h"
26 #define TRACE_BUFFER 1
29 extern void afsi_log(char *pattern, ...);
31 /* This module implements the buffer package used by the local transaction
32 * system (cm). It is initialized by calling cm_Init, which calls buf_Init;
33 * it must be initalized before any of its main routines are called.
35 * Each buffer is hashed into a hash table by file ID and offset, and if its
36 * reference count is zero, it is also in a free list.
38 * There are two locks involved in buffer processing. The global lock
39 * buf_globalLock protects all of the global variables defined in this module,
40 * the reference counts and hash pointers in the actual cm_buf_t structures,
41 * and the LRU queue pointers in the buffer structures.
43 * The mutexes in the buffer structures protect the remaining fields in the
44 * buffers, as well the data itself.
46 * The locking hierarchy here is this:
48 * - resv multiple simul. buffers reservation
49 * - lock buffer I/O flags
50 * - lock buffer's mutex
51 * - lock buf_globalLock
55 /* global debugging log */
56 osi_log_t *buf_logp = NULL;
58 /* Global lock protecting hash tables and free lists */
59 osi_rwlock_t buf_globalLock;
61 /* ptr to head of the free list (most recently used) and the
62 * tail (the guy to remove first). We use osi_Q* functions
63 * to put stuff in buf_freeListp, and maintain the end
67 /* a pointer to a list of all buffers, just so that we can find them
68 * easily for debugging, and for the incr syncer. Locked under
72 /* defaults setup; these variables may be manually assigned into
73 * before calling cm_Init, as a way of changing these defaults.
76 /* callouts for reading and writing data, etc */
77 cm_buf_ops_t *cm_buf_opsp;
80 /* for experimental disk caching support in Win95 client */
81 cm_buf_t *buf_diskFreeListp;
82 cm_buf_t *buf_diskFreeListEndp;
83 cm_buf_t *buf_diskAllp;
84 extern int cm_diskCacheEnabled;
85 #endif /* DISKCACHE95 */
87 /* set this to 1 when we are terminating to prevent access attempts */
88 static int buf_ShutdownFlag = 0;
90 void buf_HoldLocked(cm_buf_t *bp)
92 osi_assertx(bp->magic == CM_BUF_MAGIC,"incorrect cm_buf_t magic");
93 InterlockedIncrement(&bp->refCount);
96 /* hold a reference to an already held buffer */
97 void buf_Hold(cm_buf_t *bp)
99 lock_ObtainRead(&buf_globalLock);
101 lock_ReleaseRead(&buf_globalLock);
104 /* code to drop reference count while holding buf_globalLock */
105 void buf_ReleaseLocked(cm_buf_t *bp, afs_uint32 writeLocked)
110 lock_AssertWrite(&buf_globalLock);
112 lock_AssertRead(&buf_globalLock);
114 /* ensure that we're in the LRU queue if our ref count is 0 */
115 osi_assertx(bp->magic == CM_BUF_MAGIC,"incorrect cm_buf_t magic");
117 refCount = InterlockedDecrement(&bp->refCount);
120 osi_panic("buf refcount 0",__FILE__,__LINE__);;
122 osi_assertx(refCount >= 0, "cm_buf_t refCount == 0");
126 * If we are read locked there could be a race condition
127 * with buf_Find() so we must obtain a write lock and
128 * double check that the refCount is actually zero
129 * before we remove the buffer from the LRU queue.
132 lock_ConvertRToW(&buf_globalLock);
134 if (bp->refCount == 0 &&
135 !(bp->flags & CM_BUF_INLRU)) {
136 osi_QAdd((osi_queue_t **) &cm_data.buf_freeListp, &bp->q);
138 /* watch for transition from empty to one element */
139 if (!cm_data.buf_freeListEndp)
140 cm_data.buf_freeListEndp = cm_data.buf_freeListp;
141 bp->flags |= CM_BUF_INLRU;
145 lock_ConvertWToR(&buf_globalLock);
149 /* release a buffer. Buffer must be referenced, but unlocked. */
150 void buf_Release(cm_buf_t *bp)
154 /* ensure that we're in the LRU queue if our ref count is 0 */
155 osi_assertx(bp->magic == CM_BUF_MAGIC,"incorrect cm_buf_t magic");
157 refCount = InterlockedDecrement(&bp->refCount);
160 osi_panic("buf refcount 0",__FILE__,__LINE__);;
162 osi_assertx(refCount >= 0, "cm_buf_t refCount == 0");
165 lock_ObtainWrite(&buf_globalLock);
166 if (bp->refCount == 0 &&
167 !(bp->flags & CM_BUF_INLRU)) {
168 osi_QAdd((osi_queue_t **) &cm_data.buf_freeListp, &bp->q);
170 /* watch for transition from empty to one element */
171 if (!cm_data.buf_freeListEndp)
172 cm_data.buf_freeListEndp = cm_data.buf_freeListp;
173 bp->flags |= CM_BUF_INLRU;
175 lock_ReleaseWrite(&buf_globalLock);
179 /* incremental sync daemon. Writes all dirty buffers every 5000 ms */
180 void buf_IncrSyncer(long parm)
183 long i; /* counter */
187 while (buf_ShutdownFlag == 0) {
189 i = SleepEx(5000, 1);
190 if (i != 0) continue;
195 /* now go through our percentage of the buffers */
196 for (bpp = &cm_data.buf_dirtyListp; bp = *bpp; ) {
197 /* all dirty buffers are held when they are added to the
198 * dirty list. No need for an additional hold.
200 lock_ObtainMutex(&bp->mx);
201 if (bp->flags & CM_BUF_DIRTY) {
202 /* start cleaning the buffer; don't touch log pages since
203 * the log code counts on knowing exactly who is writing
204 * a log page at any given instant.
207 req.flags |= CM_REQ_NORETRY;
208 wasDirty |= buf_CleanAsyncLocked(bp, &req);
211 /* the buffer may or may not have been dirty
212 * and if dirty may or may not have been cleaned
213 * successfully. check the dirty flag again.
215 if (!(bp->flags & CM_BUF_DIRTY)) {
216 /* remove the buffer from the dirty list */
217 lock_ObtainWrite(&buf_globalLock);
220 if (cm_data.buf_dirtyListp == NULL)
221 cm_data.buf_dirtyListEndp = NULL;
222 buf_ReleaseLocked(bp, TRUE);
223 lock_ReleaseWrite(&buf_globalLock);
225 /* advance the pointer so we don't loop forever */
228 lock_ReleaseMutex(&bp->mx);
229 } /* for loop over a bunch of buffers */
230 } /* whole daemon's while loop */
234 buf_ValidateBuffers(void)
236 cm_buf_t * bp, *bpf, *bpa, *bpb;
237 afs_uint64 countb = 0, countf = 0, counta = 0;
239 if (cm_data.buf_freeListp == NULL && cm_data.buf_freeListEndp != NULL ||
240 cm_data.buf_freeListp != NULL && cm_data.buf_freeListEndp == NULL) {
241 afsi_log("cm_ValidateBuffers failure: inconsistent free list pointers");
242 fprintf(stderr, "cm_ValidateBuffers failure: inconsistent free list pointers\n");
246 for (bp = cm_data.buf_freeListEndp; bp; bp=(cm_buf_t *) osi_QPrev(&bp->q)) {
247 if (bp->magic != CM_BUF_MAGIC) {
248 afsi_log("cm_ValidateBuffers failure: bp->magic != CM_BUF_MAGIC");
249 fprintf(stderr, "cm_ValidateBuffers failure: bp->magic != CM_BUF_MAGIC\n");
255 if (countb > cm_data.buf_nbuffers) {
256 afsi_log("cm_ValidateBuffers failure: countb > cm_data.buf_nbuffers");
257 fprintf(stderr, "cm_ValidateBuffers failure: countb > cm_data.buf_nbuffers\n");
262 for (bp = cm_data.buf_freeListp; bp; bp=(cm_buf_t *) osi_QNext(&bp->q)) {
263 if (bp->magic != CM_BUF_MAGIC) {
264 afsi_log("cm_ValidateBuffers failure: bp->magic != CM_BUF_MAGIC");
265 fprintf(stderr, "cm_ValidateBuffers failure: bp->magic != CM_BUF_MAGIC\n");
271 if (countf > cm_data.buf_nbuffers) {
272 afsi_log("cm_ValidateBuffers failure: countf > cm_data.buf_nbuffers");
273 fprintf(stderr, "cm_ValidateBuffers failure: countf > cm_data.buf_nbuffers\n");
278 for (bp = cm_data.buf_allp; bp; bp=bp->allp) {
279 if (bp->magic != CM_BUF_MAGIC) {
280 afsi_log("cm_ValidateBuffers failure: bp->magic != CM_BUF_MAGIC");
281 fprintf(stderr, "cm_ValidateBuffers failure: bp->magic != CM_BUF_MAGIC\n");
287 if (counta > cm_data.buf_nbuffers) {
288 afsi_log("cm_ValidateBuffers failure: counta > cm_data.buf_nbuffers");
289 fprintf(stderr, "cm_ValidateBuffers failure: counta > cm_data.buf_nbuffers\n");
294 if (countb != countf) {
295 afsi_log("cm_ValidateBuffers failure: countb != countf");
296 fprintf(stderr, "cm_ValidateBuffers failure: countb != countf\n");
300 if (counta != cm_data.buf_nbuffers) {
301 afsi_log("cm_ValidateBuffers failure: counta != cm_data.buf_nbuffers");
302 fprintf(stderr, "cm_ValidateBuffers failure: counta != cm_data.buf_nbuffers\n");
309 void buf_Shutdown(void)
311 buf_ShutdownFlag = 1;
314 /* initialize the buffer package; called with no locks
315 * held during the initialization phase.
317 long buf_Init(int newFile, cm_buf_ops_t *opsp, afs_uint64 nbuffers)
319 static osi_once_t once;
328 cm_data.buf_nbuffers = nbuffers;
330 /* Have to be able to reserve a whole chunk */
331 if (((cm_data.buf_nbuffers - 3) * cm_data.buf_blockSize) < cm_chunkSize)
332 return CM_ERROR_TOOFEWBUFS;
335 /* recall for callouts */
338 if (osi_Once(&once)) {
339 /* initialize global locks */
340 lock_InitializeRWLock(&buf_globalLock, "Global buffer lock");
343 /* remember this for those who want to reset it */
344 cm_data.buf_nOrigBuffers = cm_data.buf_nbuffers;
346 /* lower hash size to a prime number */
347 cm_data.buf_hashSize = osi_PrimeLessThan((afs_uint32)(cm_data.buf_nbuffers/7 + 1));
349 /* create hash table */
350 memset((void *)cm_data.buf_scacheHashTablepp, 0, cm_data.buf_hashSize * sizeof(cm_buf_t *));
352 /* another hash table */
353 memset((void *)cm_data.buf_fileHashTablepp, 0, cm_data.buf_hashSize * sizeof(cm_buf_t *));
355 /* create buffer headers and put in free list */
356 bp = cm_data.bufHeaderBaseAddress;
357 data = cm_data.bufDataBaseAddress;
358 cm_data.buf_allp = NULL;
360 for (i=0; i<cm_data.buf_nbuffers; i++) {
361 osi_assertx(bp >= cm_data.bufHeaderBaseAddress && bp < (cm_buf_t *)cm_data.bufDataBaseAddress,
362 "invalid cm_buf_t address");
363 osi_assertx(data >= cm_data.bufDataBaseAddress && data < cm_data.bufEndOfData,
364 "invalid cm_buf_t data address");
366 /* allocate and zero some storage */
367 memset(bp, 0, sizeof(cm_buf_t));
368 bp->magic = CM_BUF_MAGIC;
369 /* thread on list of all buffers */
370 bp->allp = cm_data.buf_allp;
371 cm_data.buf_allp = bp;
373 osi_QAdd((osi_queue_t **)&cm_data.buf_freeListp, &bp->q);
374 bp->flags |= CM_BUF_INLRU;
375 lock_InitializeMutex(&bp->mx, "Buffer mutex");
377 /* grab appropriate number of bytes from aligned zone */
380 /* setup last buffer pointer */
382 cm_data.buf_freeListEndp = bp;
386 data += cm_data.buf_blockSize;
389 /* none reserved at first */
390 cm_data.buf_reservedBufs = 0;
392 /* just for safety's sake */
393 cm_data.buf_maxReservedBufs = cm_data.buf_nbuffers - 3;
395 bp = cm_data.bufHeaderBaseAddress;
396 data = cm_data.bufDataBaseAddress;
398 for (i=0; i<cm_data.buf_nbuffers; i++) {
399 lock_InitializeMutex(&bp->mx, "Buffer mutex");
402 bp->waitRequests = 0;
403 bp->flags &= ~CM_BUF_WAITING;
409 buf_ValidateBufQueues();
413 /* init the buffer trace log */
414 buf_logp = osi_LogCreate("buffer", 1000);
415 osi_LogEnable(buf_logp);
420 /* and create the incr-syncer */
421 phandle = thrd_Create(0, 0,
422 (ThreadFunc) buf_IncrSyncer, 0, 0, &pid,
425 osi_assertx(phandle != NULL, "buf: can't create incremental sync proc");
426 CloseHandle(phandle);
430 buf_ValidateBufQueues();
435 /* add nbuffers to the buffer pool, if possible.
436 * Called with no locks held.
438 long buf_AddBuffers(afs_uint64 nbuffers)
440 /* The size of a virtual cache cannot be changed after it has
441 * been created. Subsequent calls to MapViewofFile() with
442 * an existing mapping object name would not allow the
443 * object to be resized. Return failure immediately.
445 * A similar problem now occurs with the persistent cache
446 * given that the memory mapped file now contains a complex
449 afsi_log("request to add %d buffers to the existing cache of size %d denied",
450 nbuffers, cm_data.buf_nbuffers);
452 return CM_ERROR_INVAL;
455 /* interface to set the number of buffers to an exact figure.
456 * Called with no locks held.
458 long buf_SetNBuffers(afs_uint64 nbuffers)
461 return CM_ERROR_INVAL;
462 if (nbuffers == cm_data.buf_nbuffers)
464 else if (nbuffers > cm_data.buf_nbuffers)
465 return buf_AddBuffers(nbuffers - cm_data.buf_nbuffers);
467 return CM_ERROR_INVAL;
470 /* wait for reading or writing to clear; called with write-locked
471 * buffer and unlocked scp and returns with locked buffer.
473 void buf_WaitIO(cm_scache_t * scp, cm_buf_t *bp)
478 osi_assertx(scp->magic == CM_SCACHE_MAGIC, "invalid cm_scache_t magic");
479 osi_assertx(bp->magic == CM_BUF_MAGIC, "invalid cm_buf_t magic");
482 /* if no IO is happening, we're done */
483 if (!(bp->flags & (CM_BUF_READING | CM_BUF_WRITING)))
486 /* otherwise I/O is happening, but some other thread is waiting for
487 * the I/O already. Wait for that guy to figure out what happened,
488 * and then check again.
490 if ( bp->flags & CM_BUF_WAITING ) {
493 osi_Log1(buf_logp, "buf_WaitIO CM_BUF_WAITING already set for 0x%p", bp);
495 osi_Log1(buf_logp, "buf_WaitIO CM_BUF_WAITING set for 0x%p", bp);
496 bp->flags |= CM_BUF_WAITING;
497 bp->waitCount = bp->waitRequests = 1;
499 osi_SleepM((LONG_PTR)bp, &bp->mx);
501 smb_UpdateServerPriority();
503 lock_ObtainMutex(&bp->mx);
504 osi_Log1(buf_logp, "buf_WaitIO conflict wait done for 0x%p", bp);
506 if (bp->waitCount == 0) {
507 osi_Log1(buf_logp, "buf_WaitIO CM_BUF_WAITING reset for 0x%p", bp);
508 bp->flags &= ~CM_BUF_WAITING;
509 bp->waitRequests = 0;
513 if (scp = cm_FindSCache(&bp->fid))
517 lock_ObtainRead(&scp->rw);
518 if (scp->flags & CM_SCACHEFLAG_WAITING) {
519 osi_Log1(buf_logp, "buf_WaitIO waking scp 0x%p", scp);
520 osi_Wakeup((LONG_PTR)&scp->flags);
522 lock_ReleaseRead(&scp->rw);
526 /* if we get here, the IO is done, but we may have to wakeup people waiting for
527 * the I/O to complete. Do so.
529 if (bp->flags & CM_BUF_WAITING) {
530 osi_Log1(buf_logp, "buf_WaitIO Waking bp 0x%p", bp);
531 osi_Wakeup((LONG_PTR) bp);
533 osi_Log1(buf_logp, "WaitIO finished wait for bp 0x%p", bp);
536 cm_ReleaseSCache(scp);
539 /* find a buffer, if any, for a particular file ID and offset. Assumes
540 * that buf_globalLock is write locked when called.
542 cm_buf_t *buf_FindLocked(struct cm_scache *scp, osi_hyper_t *offsetp)
547 i = BUF_HASH(&scp->fid, offsetp);
548 for(bp = cm_data.buf_scacheHashTablepp[i]; bp; bp=bp->hashp) {
549 if (cm_FidCmp(&scp->fid, &bp->fid) == 0
550 && offsetp->LowPart == bp->offset.LowPart
551 && offsetp->HighPart == bp->offset.HighPart) {
557 /* return whatever we found, if anything */
561 /* find a buffer with offset *offsetp for vnode *scp. Called
562 * with no locks held.
564 cm_buf_t *buf_Find(struct cm_scache *scp, osi_hyper_t *offsetp)
568 lock_ObtainRead(&buf_globalLock);
569 bp = buf_FindLocked(scp, offsetp);
570 lock_ReleaseRead(&buf_globalLock);
575 /* start cleaning I/O on this buffer. Buffer must be write locked, and is returned
578 * Makes sure that there's only one person writing this block
579 * at any given time, and also ensures that the log is forced sufficiently far,
580 * if this buffer contains logged data.
582 * Returns non-zero if the buffer was dirty.
584 long buf_CleanAsyncLocked(cm_buf_t *bp, cm_req_t *reqp)
588 cm_scache_t * scp = NULL;
591 osi_assertx(bp->magic == CM_BUF_MAGIC, "invalid cm_buf_t magic");
593 while ((bp->flags & CM_BUF_DIRTY) == CM_BUF_DIRTY) {
595 lock_ReleaseMutex(&bp->mx);
597 scp = cm_FindSCache(&bp->fid);
599 osi_Log2(buf_logp, "buf_CleanAsyncLocked starts I/O on scp 0x%p buf 0x%p", scp, bp);
602 LargeIntegerAdd(offset, ConvertLongToLargeInteger(bp->dirty_offset));
603 code = (*cm_buf_opsp->Writep)(scp, &offset,
605 /* we might as well try to write all of the contiguous
606 * dirty buffers in one RPC
613 osi_Log3(buf_logp, "buf_CleanAsyncLocked I/O on scp 0x%p buf 0x%p, done=%d", scp, bp, code);
615 cm_ReleaseSCache(scp);
618 osi_Log1(buf_logp, "buf_CleanAsyncLocked unable to start I/O - scp not found buf 0x%p", bp);
619 code = CM_ERROR_NOSUCHFILE;
622 lock_ObtainMutex(&bp->mx);
623 /* if the Write routine returns No Such File, clear the dirty flag
624 * because we aren't going to be able to write this data to the file
627 if (code == CM_ERROR_NOSUCHFILE || code == CM_ERROR_BADFD){
628 bp->flags &= ~CM_BUF_DIRTY;
629 bp->flags |= CM_BUF_ERROR;
630 bp->dirty_offset = 0;
631 bp->dirty_length = 0;
633 bp->dataVersion = CM_BUF_VERSION_BAD; /* bad */
638 /* Disk cache support */
639 /* write buffer to disk cache (synchronous for now) */
640 diskcache_Update(bp->dcp, bp->datap, cm_data.buf_blockSize, bp->dataVersion);
641 #endif /* DISKCACHE95 */
643 /* if we get here and retries are not permitted
644 * then we need to exit this loop regardless of
645 * whether or not we were able to clear the dirty bit
647 if (reqp->flags & CM_REQ_NORETRY)
651 if (!(bp->flags & CM_BUF_DIRTY)) {
652 /* remove buffer from dirty buffer queue */
656 /* do logging after call to GetLastError, or else */
658 /* if someone was waiting for the I/O that just completed or failed,
661 if (bp->flags & CM_BUF_WAITING) {
662 /* turn off flags and wakeup users */
663 osi_Log1(buf_logp, "buf_WaitIO Waking bp 0x%p", bp);
664 osi_Wakeup((LONG_PTR) bp);
669 /* Called with a zero-ref count buffer and with the buf_globalLock write locked.
670 * recycles the buffer, and leaves it ready for reuse with a ref count of 1.
671 * The buffer must already be clean, and no I/O should be happening to it.
673 void buf_Recycle(cm_buf_t *bp)
678 cm_buf_t *prevBp, *nextBp;
680 osi_assertx(bp->magic == CM_BUF_MAGIC, "invalid cm_buf_t magic");
682 /* if we get here, we know that the buffer still has a 0 ref count,
683 * and that it is clean and has no currently pending I/O. This is
684 * the dude to return.
685 * Remember that as long as the ref count is 0, we know that we won't
686 * have any lock conflicts, so we can grab the buffer lock out of
687 * order in the locking hierarchy.
689 osi_Log3( buf_logp, "buf_Recycle recycles 0x%p, off 0x%x:%08x",
690 bp, bp->offset.HighPart, bp->offset.LowPart);
692 osi_assertx(bp->refCount == 0, "cm_buf_t refcount != 0");
693 osi_assertx(!(bp->flags & (CM_BUF_READING | CM_BUF_WRITING | CM_BUF_DIRTY)),
694 "incorrect cm_buf_t flags");
695 lock_AssertWrite(&buf_globalLock);
697 if (bp->flags & CM_BUF_INHASH) {
698 /* Remove from hash */
700 i = BUF_HASH(&bp->fid, &bp->offset);
701 lbpp = &(cm_data.buf_scacheHashTablepp[i]);
702 for(tbp = *lbpp; tbp; lbpp = &tbp->hashp, tbp = *lbpp) {
707 /* we better find it */
708 osi_assertx(tbp != NULL, "buf_Recycle: hash table screwup");
710 *lbpp = bp->hashp; /* hash out */
713 /* Remove from file hash */
715 i = BUF_FILEHASH(&bp->fid);
716 prevBp = bp->fileHashBackp;
717 bp->fileHashBackp = NULL;
718 nextBp = bp->fileHashp;
719 bp->fileHashp = NULL;
721 prevBp->fileHashp = nextBp;
723 cm_data.buf_fileHashTablepp[i] = nextBp;
725 nextBp->fileHashBackp = prevBp;
727 bp->flags &= ~CM_BUF_INHASH;
730 /* make the fid unrecognizable */
731 memset(&bp->fid, 0, sizeof(cm_fid_t));
734 /* recycle a buffer, removing it from the free list, hashing in its new identity
735 * and returning it write-locked so that no one can use it. Called without
736 * any locks held, and can return an error if it loses the race condition and
737 * finds that someone else created the desired buffer.
739 * If success is returned, the buffer is returned write-locked.
741 * May be called with null scp and offsetp, if we're just trying to reclaim some
742 * space from the buffer pool. In that case, the buffer will be returned
743 * without being hashed into the hash table.
745 long buf_GetNewLocked(struct cm_scache *scp, osi_hyper_t *offsetp, cm_buf_t **bufpp)
747 cm_buf_t *bp; /* buffer we're dealing with */
748 cm_buf_t *nextBp; /* next buffer in file hash chain */
749 afs_uint32 i; /* temp */
752 cm_InitReq(&req); /* just in case */
755 buf_ValidateBufQueues();
760 lock_ObtainRead(&scp->bufCreateLock);
761 lock_ObtainWrite(&buf_globalLock);
762 /* check to see if we lost the race */
764 if (bp = buf_FindLocked(scp, offsetp)) {
765 /* Do not call buf_ReleaseLocked() because we
766 * do not want to allow the buffer to be added
770 lock_ReleaseWrite(&buf_globalLock);
771 lock_ReleaseRead(&scp->bufCreateLock);
772 return CM_BUF_EXISTS;
776 /* does this fix the problem below? it's a simple solution. */
777 if (!cm_data.buf_freeListEndp)
779 lock_ReleaseWrite(&buf_globalLock);
780 lock_ReleaseRead(&scp->bufCreateLock);
781 osi_Log0(afsd_logp, "buf_GetNewLocked: Free Buffer List is empty - sleeping 200ms");
786 /* for debugging, assert free list isn't empty, although we
787 * really should try waiting for a running tranasction to finish
788 * instead of this; or better, we should have a transaction
789 * throttler prevent us from entering this situation.
791 osi_assertx(cm_data.buf_freeListEndp != NULL, "buf_GetNewLocked: no free buffers");
793 /* look at all buffers in free list, some of which may temp.
794 * have high refcounts and which then should be skipped,
795 * starting cleaning I/O for those which are dirty. If we find
796 * a clean buffer, we rehash it, lock it and return it.
798 for(bp = cm_data.buf_freeListEndp; bp; bp=(cm_buf_t *) osi_QPrev(&bp->q)) {
799 /* check to see if it really has zero ref count. This
800 * code can bump refcounts, at least, so it may not be
803 if (bp->refCount > 0)
806 /* we don't have to lock buffer itself, since the ref
807 * count is 0 and we know it will stay zero as long as
808 * we hold the global lock.
811 /* don't recycle someone in our own chunk */
812 if (!cm_FidCmp(&bp->fid, &scp->fid)
813 && (bp->offset.LowPart & (-cm_chunkSize))
814 == (offsetp->LowPart & (-cm_chunkSize)))
817 /* if this page is being filled (!) or cleaned, see if
818 * the I/O has completed. If not, skip it, otherwise
819 * do the final processing for the I/O.
821 if (bp->flags & (CM_BUF_READING | CM_BUF_WRITING)) {
822 /* probably shouldn't do this much work while
823 * holding the big lock? Watch for contention
829 if (bp->flags & CM_BUF_DIRTY) {
830 /* if the buffer is dirty, start cleaning it and
831 * move on to the next buffer. We do this with
832 * just the lock required to minimize contention
836 lock_ReleaseWrite(&buf_globalLock);
837 lock_ReleaseRead(&scp->bufCreateLock);
839 /* grab required lock and clean; this only
840 * starts the I/O. By the time we're back,
841 * it'll still be marked dirty, but it will also
842 * have the WRITING flag set, so we won't get
845 buf_CleanAsync(bp, &req);
847 /* now put it back and go around again */
852 /* if we get here, we know that the buffer still has a 0
853 * ref count, and that it is clean and has no currently
854 * pending I/O. This is the dude to return.
855 * Remember that as long as the ref count is 0, we know
856 * that we won't have any lock conflicts, so we can grab
857 * the buffer lock out of order in the locking hierarchy.
861 /* clean up junk flags */
862 bp->flags &= ~(CM_BUF_EOF | CM_BUF_ERROR);
863 bp->dataVersion = CM_BUF_VERSION_BAD; /* unknown so far */
865 /* now hash in as our new buffer, and give it the
866 * appropriate label, if requested.
869 bp->flags |= CM_BUF_INHASH;
874 bp->offset = *offsetp;
875 i = BUF_HASH(&scp->fid, offsetp);
876 bp->hashp = cm_data.buf_scacheHashTablepp[i];
877 cm_data.buf_scacheHashTablepp[i] = bp;
878 i = BUF_FILEHASH(&scp->fid);
879 nextBp = cm_data.buf_fileHashTablepp[i];
880 bp->fileHashp = nextBp;
881 bp->fileHashBackp = NULL;
883 nextBp->fileHashBackp = bp;
884 cm_data.buf_fileHashTablepp[i] = bp;
887 /* we should move it from the lru queue. It better still be there,
888 * since we've held the global (big) lock since we found it there.
890 osi_assertx(bp->flags & CM_BUF_INLRU,
891 "buf_GetNewLocked: LRU screwup");
893 if (cm_data.buf_freeListEndp == bp) {
894 /* we're the last guy in this queue, so maintain it */
895 cm_data.buf_freeListEndp = (cm_buf_t *) osi_QPrev(&bp->q);
897 osi_QRemove((osi_queue_t **) &cm_data.buf_freeListp, &bp->q);
898 bp->flags &= ~CM_BUF_INLRU;
900 /* grab the mutex so that people don't use it
901 * before the caller fills it with data. Again, no one
902 * should have been able to get to this dude to lock it.
904 if (!lock_TryMutex(&bp->mx)) {
905 osi_Log2(afsd_logp, "buf_GetNewLocked bp 0x%p cannot be mutex locked. refCount %d should be 0",
907 osi_panic("buf_GetNewLocked: TryMutex failed",__FILE__,__LINE__);
910 /* prepare to return it. Give it a refcount */
913 lock_ReleaseWrite(&buf_globalLock);
914 lock_ReleaseRead(&scp->bufCreateLock);
918 buf_ValidateBufQueues();
921 } /* for all buffers in lru queue */
922 lock_ReleaseWrite(&buf_globalLock);
923 lock_ReleaseRead(&scp->bufCreateLock);
924 osi_Log0(afsd_logp, "buf_GetNewLocked: Free Buffer List has no buffers with a zero refcount - sleeping 100ms");
925 Sleep(100); /* give some time for a buffer to be freed */
926 } /* while loop over everything */
930 /* get a page, returning it held but unlocked. Doesn't fill in the page
931 * with I/O, since we're going to write the whole thing new.
933 long buf_GetNew(struct cm_scache *scp, osi_hyper_t *offsetp, cm_buf_t **bufpp)
937 osi_hyper_t pageOffset;
941 pageOffset.HighPart = offsetp->HighPart;
942 pageOffset.LowPart = offsetp->LowPart & ~(cm_data.buf_blockSize-1);
944 bp = buf_Find(scp, &pageOffset);
946 /* lock it and break out */
947 lock_ObtainMutex(&bp->mx);
951 /* otherwise, we have to create a page */
952 code = buf_GetNewLocked(scp, &pageOffset, &bp);
954 /* check if the buffer was created in a race condition branch.
955 * If so, go around so we can hold a reference to it.
957 if (code == CM_BUF_EXISTS)
960 /* something else went wrong */
964 /* otherwise, we have a locked buffer that we just created */
967 } /* big while loop */
970 if (bp->flags & CM_BUF_READING)
973 /* once it has been read once, we can unlock it and return it, still
974 * with its refcount held.
976 lock_ReleaseMutex(&bp->mx);
978 osi_Log4(buf_logp, "buf_GetNew returning bp 0x%p for scp 0x%p, offset 0x%x:%08x",
979 bp, scp, offsetp->HighPart, offsetp->LowPart);
983 /* get a page, returning it held but unlocked. Make sure it is complete */
984 /* The scp must be unlocked when passed to this function */
985 long buf_Get(struct cm_scache *scp, osi_hyper_t *offsetp, cm_buf_t **bufpp)
989 osi_hyper_t pageOffset;
990 unsigned long tcount;
995 #endif /* DISKCACHE95 */
998 pageOffset.HighPart = offsetp->HighPart;
999 pageOffset.LowPart = offsetp->LowPart & ~(cm_data.buf_blockSize-1);
1003 buf_ValidateBufQueues();
1004 #endif /* TESTING */
1006 bp = buf_Find(scp, &pageOffset);
1008 /* lock it and break out */
1009 lock_ObtainMutex(&bp->mx);
1012 /* touch disk chunk to update LRU info */
1013 diskcache_Touch(bp->dcp);
1014 #endif /* DISKCACHE95 */
1018 /* otherwise, we have to create a page */
1019 code = buf_GetNewLocked(scp, &pageOffset, &bp);
1020 /* bp->mx is now held */
1022 /* check if the buffer was created in a race condition branch.
1023 * If so, go around so we can hold a reference to it.
1025 if (code == CM_BUF_EXISTS)
1028 /* something else went wrong */
1031 buf_ValidateBufQueues();
1032 #endif /* TESTING */
1036 /* otherwise, we have a locked buffer that we just created */
1039 } /* big while loop */
1041 /* if we get here, we have a locked buffer that may have just been
1042 * created, in which case it needs to be filled with data.
1045 /* load the page; freshly created pages should be idle */
1046 osi_assertx(!(bp->flags & (CM_BUF_READING | CM_BUF_WRITING)), "incorrect cm_buf_t flags");
1048 /* start the I/O; may drop lock */
1049 bp->flags |= CM_BUF_READING;
1050 code = (*cm_buf_opsp->Readp)(bp, cm_data.buf_blockSize, &tcount, NULL);
1053 code = diskcache_Get(&bp->fid, &bp->offset, bp->datap, cm_data.buf_blockSize, &bp->dataVersion, &tcount, &dcp);
1054 bp->dcp = dcp; /* pointer to disk cache struct. */
1055 #endif /* DISKCACHE95 */
1058 /* failure or queued */
1059 if (code != ERROR_IO_PENDING) {
1061 bp->flags |= CM_BUF_ERROR;
1062 bp->flags &= ~CM_BUF_READING;
1063 if (bp->flags & CM_BUF_WAITING) {
1064 osi_Log1(buf_logp, "buf_Get Waking bp 0x%p", bp);
1065 osi_Wakeup((LONG_PTR) bp);
1067 lock_ReleaseMutex(&bp->mx);
1070 buf_ValidateBufQueues();
1071 #endif /* TESTING */
1075 /* otherwise, I/O completed instantly and we're done, except
1076 * for padding the xfr out with 0s and checking for EOF
1078 if (tcount < (unsigned long) cm_data.buf_blockSize) {
1079 memset(bp->datap+tcount, 0, cm_data.buf_blockSize - tcount);
1081 bp->flags |= CM_BUF_EOF;
1083 bp->flags &= ~CM_BUF_READING;
1084 if (bp->flags & CM_BUF_WAITING) {
1085 osi_Log1(buf_logp, "buf_Get Waking bp 0x%p", bp);
1086 osi_Wakeup((LONG_PTR) bp);
1092 /* wait for reads, either that which we started above, or that someone
1093 * else started. We don't care if we return a buffer being cleaned.
1095 if (bp->flags & CM_BUF_READING)
1096 buf_WaitIO(scp, bp);
1098 /* once it has been read once, we can unlock it and return it, still
1099 * with its refcount held.
1101 lock_ReleaseMutex(&bp->mx);
1104 /* now remove from queue; will be put in at the head (farthest from
1105 * being recycled) when we're done in buf_Release.
1107 lock_ObtainWrite(&buf_globalLock);
1108 if (bp->flags & CM_BUF_INLRU) {
1109 if (cm_data.buf_freeListEndp == bp)
1110 cm_data.buf_freeListEndp = (cm_buf_t *) osi_QPrev(&bp->q);
1111 osi_QRemove((osi_queue_t **) &cm_data.buf_freeListp, &bp->q);
1112 bp->flags &= ~CM_BUF_INLRU;
1114 lock_ReleaseWrite(&buf_globalLock);
1116 osi_Log4(buf_logp, "buf_Get returning bp 0x%p for scp 0x%p, offset 0x%x:%08x",
1117 bp, scp, offsetp->HighPart, offsetp->LowPart);
1119 buf_ValidateBufQueues();
1120 #endif /* TESTING */
1124 /* count # of elements in the free list;
1125 * we don't bother doing the proper locking for accessing dataVersion or flags
1126 * since it is a pain, and this is really just an advisory call. If you need
1127 * to do better at some point, rewrite this function.
1129 long buf_CountFreeList(void)
1135 lock_ObtainRead(&buf_globalLock);
1136 for(bufp = cm_data.buf_freeListp; bufp; bufp = (cm_buf_t *) osi_QNext(&bufp->q)) {
1137 /* if the buffer doesn't have an identity, or if the buffer
1138 * has been invalidate (by having its DV stomped upon), then
1139 * count it as free, since it isn't really being utilized.
1141 if (!(bufp->flags & CM_BUF_INHASH) || bufp->dataVersion <= 0)
1144 lock_ReleaseRead(&buf_globalLock);
1148 /* clean a buffer synchronously */
1149 long buf_CleanAsync(cm_buf_t *bp, cm_req_t *reqp)
1152 osi_assertx(bp->magic == CM_BUF_MAGIC, "invalid cm_buf_t magic");
1154 lock_ObtainMutex(&bp->mx);
1155 code = buf_CleanAsyncLocked(bp, reqp);
1156 lock_ReleaseMutex(&bp->mx);
1161 /* wait for a buffer's cleaning to finish */
1162 void buf_CleanWait(cm_scache_t * scp, cm_buf_t *bp, afs_uint32 locked)
1164 osi_assertx(bp->magic == CM_BUF_MAGIC, "invalid cm_buf_t magic");
1167 lock_ObtainMutex(&bp->mx);
1168 if (bp->flags & CM_BUF_WRITING) {
1169 buf_WaitIO(scp, bp);
1172 lock_ReleaseMutex(&bp->mx);
1175 /* set the dirty flag on a buffer, and set associated write-ahead log,
1176 * if there is one. Allow one to be added to a buffer, but not changed.
1178 * The buffer must be locked before calling this routine.
1180 void buf_SetDirty(cm_buf_t *bp, afs_uint32 offset, afs_uint32 length)
1182 osi_assertx(bp->magic == CM_BUF_MAGIC, "invalid cm_buf_t magic");
1183 osi_assertx(bp->refCount > 0, "cm_buf_t refcount 0");
1185 if (bp->flags & CM_BUF_DIRTY) {
1187 osi_Log1(buf_logp, "buf_SetDirty 0x%p already dirty", bp);
1189 if (bp->dirty_offset <= offset) {
1190 if (bp->dirty_offset + bp->dirty_length >= offset + length) {
1191 /* dirty_length remains the same */
1193 bp->dirty_length = offset + length - bp->dirty_offset;
1195 } else /* bp->dirty_offset > offset */ {
1196 if (bp->dirty_offset + bp->dirty_length >= offset + length) {
1197 bp->dirty_length = bp->dirty_offset + bp->dirty_length - offset;
1199 bp->dirty_length = length;
1201 bp->dirty_offset = offset;
1204 osi_Log1(buf_logp, "buf_SetDirty 0x%p", bp);
1207 bp->flags |= CM_BUF_DIRTY;
1209 /* and turn off EOF flag, since it has associated data now */
1210 bp->flags &= ~CM_BUF_EOF;
1212 bp->dirty_offset = offset;
1213 bp->dirty_length = length;
1215 /* and add to the dirty list.
1216 * we obtain a hold on the buffer for as long as it remains
1217 * in the list. buffers are only removed from the list by
1218 * the buf_IncrSyncer function regardless of when else the
1219 * dirty flag might be cleared.
1221 * This should never happen but just in case there is a bug
1222 * elsewhere, never add to the dirty list if the buffer is
1225 lock_ObtainWrite(&buf_globalLock);
1226 if (bp->dirtyp == NULL && cm_data.buf_dirtyListEndp != bp) {
1228 if (!cm_data.buf_dirtyListp) {
1229 cm_data.buf_dirtyListp = cm_data.buf_dirtyListEndp = bp;
1231 cm_data.buf_dirtyListEndp->dirtyp = bp;
1232 cm_data.buf_dirtyListEndp = bp;
1236 lock_ReleaseWrite(&buf_globalLock);
1240 /* clean all buffers, reset log pointers and invalidate all buffers.
1241 * Called with no locks held, and returns with same.
1243 * This function is guaranteed to clean and remove the log ptr of all the
1244 * buffers that were dirty or had non-zero log ptrs before the call was
1245 * made. That's sufficient to clean up any garbage left around by recovery,
1246 * which is all we're counting on this for; there may be newly created buffers
1247 * added while we're running, but that should be OK.
1249 * In an environment where there are no transactions (artificially imposed, for
1250 * example, when switching the database to raw mode), this function is used to
1251 * make sure that all updates have been written to the disk. In that case, we don't
1252 * really require that we forget the log association between pages and logs, but
1253 * it also doesn't hurt. Since raw mode I/O goes through this buffer package, we don't
1254 * have to worry about invalidating data in the buffers.
1256 * This function is used at the end of recovery as paranoia to get the recovered
1257 * database out to disk. It removes all references to the recovery log and cleans
1260 long buf_CleanAndReset(void)
1266 lock_ObtainRead(&buf_globalLock);
1267 for(i=0; i<cm_data.buf_hashSize; i++) {
1268 for(bp = cm_data.buf_scacheHashTablepp[i]; bp; bp = bp->hashp) {
1269 if ((bp->flags & CM_BUF_DIRTY) == CM_BUF_DIRTY) {
1271 lock_ReleaseRead(&buf_globalLock);
1273 /* now no locks are held; clean buffer and go on */
1275 req.flags |= CM_REQ_NORETRY;
1277 buf_CleanAsync(bp, &req);
1278 buf_CleanWait(NULL, bp, FALSE);
1280 /* relock and release buffer */
1281 lock_ObtainRead(&buf_globalLock);
1282 buf_ReleaseLocked(bp, FALSE);
1284 } /* over one bucket */
1285 } /* for loop over all hash buckets */
1288 lock_ReleaseRead(&buf_globalLock);
1291 buf_ValidateBufQueues();
1292 #endif /* TESTING */
1294 /* and we're done */
1298 /* called without global lock being held, reserves buffers for callers
1299 * that need more than one held (not locked) at once.
1301 void buf_ReserveBuffers(afs_uint64 nbuffers)
1303 lock_ObtainWrite(&buf_globalLock);
1305 if (cm_data.buf_reservedBufs + nbuffers > cm_data.buf_maxReservedBufs) {
1306 cm_data.buf_reserveWaiting = 1;
1307 osi_Log1(buf_logp, "buf_ReserveBuffers waiting for %d bufs", nbuffers);
1308 osi_SleepW((LONG_PTR) &cm_data.buf_reservedBufs, &buf_globalLock);
1309 lock_ObtainWrite(&buf_globalLock);
1312 cm_data.buf_reservedBufs += nbuffers;
1316 lock_ReleaseWrite(&buf_globalLock);
1319 int buf_TryReserveBuffers(afs_uint64 nbuffers)
1323 lock_ObtainWrite(&buf_globalLock);
1324 if (cm_data.buf_reservedBufs + nbuffers > cm_data.buf_maxReservedBufs) {
1328 cm_data.buf_reservedBufs += nbuffers;
1331 lock_ReleaseWrite(&buf_globalLock);
1335 /* called without global lock held, releases reservation held by
1336 * buf_ReserveBuffers.
1338 void buf_UnreserveBuffers(afs_uint64 nbuffers)
1340 lock_ObtainWrite(&buf_globalLock);
1341 cm_data.buf_reservedBufs -= nbuffers;
1342 if (cm_data.buf_reserveWaiting) {
1343 cm_data.buf_reserveWaiting = 0;
1344 osi_Wakeup((LONG_PTR) &cm_data.buf_reservedBufs);
1346 lock_ReleaseWrite(&buf_globalLock);
1349 /* truncate the buffers past sizep, zeroing out the page, if we don't
1350 * end on a page boundary.
1352 * Requires cm_bufCreateLock to be write locked.
1354 long buf_Truncate(cm_scache_t *scp, cm_user_t *userp, cm_req_t *reqp,
1358 cm_buf_t *nbufp; /* next buffer, if didRelease */
1364 /* assert that cm_bufCreateLock is held in write mode */
1365 lock_AssertWrite(&scp->bufCreateLock);
1367 i = BUF_FILEHASH(&scp->fid);
1369 lock_ObtainRead(&buf_globalLock);
1370 bufp = cm_data.buf_fileHashTablepp[i];
1372 lock_ReleaseRead(&buf_globalLock);
1376 buf_HoldLocked(bufp);
1377 lock_ReleaseRead(&buf_globalLock);
1379 lock_ObtainMutex(&bufp->mx);
1381 bufEnd.HighPart = 0;
1382 bufEnd.LowPart = cm_data.buf_blockSize;
1383 bufEnd = LargeIntegerAdd(bufEnd, bufp->offset);
1385 if (cm_FidCmp(&bufp->fid, &scp->fid) == 0 &&
1386 LargeIntegerLessThan(*sizep, bufEnd)) {
1387 buf_WaitIO(scp, bufp);
1389 lock_ObtainWrite(&scp->rw);
1391 /* make sure we have a callback (so we have the right value for
1392 * the length), and wait for it to be safe to do a truncate.
1394 code = cm_SyncOp(scp, bufp, userp, reqp, 0,
1395 CM_SCACHESYNC_NEEDCALLBACK
1396 | CM_SCACHESYNC_GETSTATUS
1397 | CM_SCACHESYNC_SETSIZE
1398 | CM_SCACHESYNC_BUFLOCKED);
1401 /* if we succeeded in our locking, and this applies to the right
1402 * file, and the truncate request overlaps the buffer either
1403 * totally or partially, then do something.
1405 if (code == 0 && cm_FidCmp(&bufp->fid, &scp->fid) == 0
1406 && LargeIntegerLessThan(*sizep, bufEnd)) {
1409 /* destroy the buffer, turning off its dirty bit, if
1410 * we're truncating the whole buffer. Otherwise, set
1411 * the dirty bit, and clear out the tail of the buffer
1412 * if we just overlap some.
1414 if (LargeIntegerLessThanOrEqualTo(*sizep, bufp->offset)) {
1415 /* truncating the entire page */
1416 bufp->flags &= ~CM_BUF_DIRTY;
1417 bufp->dirty_offset = 0;
1418 bufp->dirty_length = 0;
1419 bufp->dataVersion = CM_BUF_VERSION_BAD; /* known bad */
1420 bufp->dirtyCounter++;
1423 /* don't set dirty, since dirty implies
1424 * currently up-to-date. Don't need to do this,
1425 * since we'll update the length anyway.
1427 * Zero out remainder of the page, in case we
1428 * seek and write past EOF, and make this data
1431 bufferPos = sizep->LowPart & (cm_data.buf_blockSize - 1);
1432 osi_assertx(bufferPos != 0, "non-zero bufferPos");
1433 memset(bufp->datap + bufferPos, 0,
1434 cm_data.buf_blockSize - bufferPos);
1438 cm_SyncOpDone( scp, bufp,
1439 CM_SCACHESYNC_NEEDCALLBACK | CM_SCACHESYNC_GETSTATUS
1440 | CM_SCACHESYNC_SETSIZE | CM_SCACHESYNC_BUFLOCKED);
1442 lock_ReleaseWrite(&scp->rw);
1443 lock_ReleaseMutex(&bufp->mx);
1446 nbufp = bufp->fileHashp;
1450 /* This forces the loop to end and the error code
1451 * to be returned. */
1459 buf_ValidateBufQueues();
1460 #endif /* TESTING */
1466 long buf_FlushCleanPages(cm_scache_t *scp, cm_user_t *userp, cm_req_t *reqp)
1469 cm_buf_t *bp; /* buffer we're hacking on */
1474 i = BUF_FILEHASH(&scp->fid);
1477 lock_ObtainRead(&buf_globalLock);
1478 bp = cm_data.buf_fileHashTablepp[i];
1481 lock_ReleaseRead(&buf_globalLock);
1483 for (; bp; bp = nbp) {
1484 didRelease = 0; /* haven't released this buffer yet */
1486 /* clean buffer synchronously */
1487 if (cm_FidCmp(&bp->fid, &scp->fid) == 0) {
1488 lock_ObtainMutex(&bp->mx);
1490 /* start cleaning the buffer, and wait for it to finish */
1491 buf_CleanAsyncLocked(bp, reqp);
1492 buf_WaitIO(scp, bp);
1493 lock_ReleaseMutex(&bp->mx);
1495 code = (*cm_buf_opsp->Stabilizep)(scp, userp, reqp);
1496 if (code && code != CM_ERROR_BADFD)
1499 if (code == CM_ERROR_BADFD) {
1500 /* if the scp's FID is bad its because we received VNOVNODE
1501 * when attempting to FetchStatus before the write. This
1502 * page therefore contains data that can no longer be stored.
1504 lock_ObtainMutex(&bp->mx);
1505 bp->flags &= ~CM_BUF_DIRTY;
1506 bp->flags |= CM_BUF_ERROR;
1507 bp->error = CM_ERROR_BADFD;
1508 bp->dirty_offset = 0;
1509 bp->dirty_length = 0;
1510 bp->dataVersion = CM_BUF_VERSION_BAD; /* known bad */
1512 lock_ReleaseMutex(&bp->mx);
1515 /* actually, we only know that buffer is clean if ref
1516 * count is 1, since we don't have buffer itself locked.
1518 if (!(bp->flags & CM_BUF_DIRTY)) {
1519 lock_ObtainWrite(&buf_globalLock);
1520 if (bp->refCount == 1) { /* bp is held above */
1521 nbp = bp->fileHashp;
1523 buf_HoldLocked(nbp);
1524 buf_ReleaseLocked(bp, TRUE);
1528 lock_ReleaseWrite(&buf_globalLock);
1532 (*cm_buf_opsp->Unstabilizep)(scp, userp);
1537 lock_ObtainRead(&buf_globalLock);
1538 nbp = bp->fileHashp;
1540 buf_HoldLocked(nbp);
1541 buf_ReleaseLocked(bp, FALSE);
1542 lock_ReleaseRead(&buf_globalLock);
1544 } /* for loop over a bunch of buffers */
1547 buf_ValidateBufQueues();
1548 #endif /* TESTING */
1554 /* Must be called with scp->rw held */
1555 long buf_ForceDataVersion(cm_scache_t * scp, afs_uint64 fromVersion, afs_uint64 toVersion)
1561 lock_AssertAny(&scp->rw);
1563 i = BUF_FILEHASH(&scp->fid);
1565 lock_ObtainRead(&buf_globalLock);
1567 for (bp = cm_data.buf_fileHashTablepp[i]; bp; bp = bp->fileHashp) {
1568 if (cm_FidCmp(&bp->fid, &scp->fid) == 0) {
1569 if (bp->dataVersion == fromVersion) {
1570 bp->dataVersion = toVersion;
1575 lock_ReleaseRead(&buf_globalLock);
1583 long buf_CleanVnode(struct cm_scache *scp, cm_user_t *userp, cm_req_t *reqp)
1587 cm_buf_t *bp; /* buffer we're hacking on */
1588 cm_buf_t *nbp; /* next one */
1591 i = BUF_FILEHASH(&scp->fid);
1593 lock_ObtainRead(&buf_globalLock);
1594 bp = cm_data.buf_fileHashTablepp[i];
1597 lock_ReleaseRead(&buf_globalLock);
1598 for (; bp; bp = nbp) {
1599 /* clean buffer synchronously */
1600 if (cm_FidCmp(&bp->fid, &scp->fid) == 0) {
1601 lock_ObtainMutex(&bp->mx);
1602 if (bp->flags & CM_BUF_DIRTY) {
1606 cm_ReleaseUser(bp->userp);
1609 wasDirty = buf_CleanAsyncLocked(bp, reqp);
1610 buf_CleanWait(scp, bp, TRUE);
1611 if (bp->flags & CM_BUF_ERROR) {
1617 lock_ReleaseMutex(&bp->mx);
1620 lock_ObtainRead(&buf_globalLock);
1621 nbp = bp->fileHashp;
1623 buf_HoldLocked(nbp);
1624 buf_ReleaseLocked(bp, FALSE);
1625 lock_ReleaseRead(&buf_globalLock);
1626 } /* for loop over a bunch of buffers */
1629 buf_ValidateBufQueues();
1630 #endif /* TESTING */
1638 buf_ValidateBufQueues(void)
1640 cm_buf_t * bp, *bpb, *bpf, *bpa;
1641 afs_uint32 countf=0, countb=0, counta=0;
1643 lock_ObtainRead(&buf_globalLock);
1644 for (bp = cm_data.buf_freeListEndp; bp; bp=(cm_buf_t *) osi_QPrev(&bp->q)) {
1645 if (bp->magic != CM_BUF_MAGIC)
1646 osi_panic("buf magic error",__FILE__,__LINE__);
1651 for (bp = cm_data.buf_freeListp; bp; bp=(cm_buf_t *) osi_QNext(&bp->q)) {
1652 if (bp->magic != CM_BUF_MAGIC)
1653 osi_panic("buf magic error",__FILE__,__LINE__);
1658 for (bp = cm_data.buf_allp; bp; bp=bp->allp) {
1659 if (bp->magic != CM_BUF_MAGIC)
1660 osi_panic("buf magic error",__FILE__,__LINE__);
1664 lock_ReleaseRead(&buf_globalLock);
1666 if (countb != countf)
1667 osi_panic("buf magic error",__FILE__,__LINE__);
1669 if (counta != cm_data.buf_nbuffers)
1670 osi_panic("buf magic error",__FILE__,__LINE__);
1672 #endif /* TESTING */
1674 /* dump the contents of the buf_scacheHashTablepp. */
1675 int cm_DumpBufHashTable(FILE *outputFile, char *cookie, int lock)
1682 if (cm_data.buf_scacheHashTablepp == NULL)
1686 lock_ObtainRead(&buf_globalLock);
1688 StringCbPrintfA(output, sizeof(output), "%s - dumping buf_HashTable - buf_hashSize=%d\r\n",
1689 cookie, cm_data.buf_hashSize);
1690 WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
1692 for (i = 0; i < cm_data.buf_hashSize; i++)
1694 for (bp = cm_data.buf_scacheHashTablepp[i]; bp; bp=bp->hashp)
1696 StringCbPrintfA(output, sizeof(output),
1697 "%s bp=0x%08X, hash=%d, fid (cell=%d, volume=%d, "
1698 "vnode=%d, unique=%d), offset=%x:%08x, dv=%I64d, "
1699 "flags=0x%x, cmFlags=0x%x, refCount=%d\r\n",
1700 cookie, (void *)bp, i, bp->fid.cell, bp->fid.volume,
1701 bp->fid.vnode, bp->fid.unique, bp->offset.HighPart,
1702 bp->offset.LowPart, bp->dataVersion, bp->flags,
1703 bp->cmFlags, bp->refCount);
1704 WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
1708 StringCbPrintfA(output, sizeof(output), "%s - Done dumping buf_HashTable.\r\n", cookie);
1709 WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
1711 StringCbPrintfA(output, sizeof(output), "%s - dumping buf_freeListEndp\r\n", cookie);
1712 WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
1713 for(bp = cm_data.buf_freeListEndp; bp; bp=(cm_buf_t *) osi_QPrev(&bp->q)) {
1714 StringCbPrintfA(output, sizeof(output),
1715 "%s bp=0x%08X, fid (cell=%d, volume=%d, "
1716 "vnode=%d, unique=%d), offset=%x:%08x, dv=%I64d, "
1717 "flags=0x%x, cmFlags=0x%x, refCount=%d\r\n",
1718 cookie, (void *)bp, bp->fid.cell, bp->fid.volume,
1719 bp->fid.vnode, bp->fid.unique, bp->offset.HighPart,
1720 bp->offset.LowPart, bp->dataVersion, bp->flags,
1721 bp->cmFlags, bp->refCount);
1722 WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
1724 StringCbPrintfA(output, sizeof(output), "%s - Done dumping buf_FreeListEndp.\r\n", cookie);
1725 WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
1727 StringCbPrintfA(output, sizeof(output), "%s - dumping buf_dirtyListEndp\r\n", cookie);
1728 WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
1729 for(bp = cm_data.buf_dirtyListEndp; bp; bp=(cm_buf_t *) osi_QPrev(&bp->q)) {
1730 StringCbPrintfA(output, sizeof(output),
1731 "%s bp=0x%08X, fid (cell=%d, volume=%d, "
1732 "vnode=%d, unique=%d), offset=%x:%08x, dv=%I64d, "
1733 "flags=0x%x, cmFlags=0x%x, refCount=%d\r\n",
1734 cookie, (void *)bp, bp->fid.cell, bp->fid.volume,
1735 bp->fid.vnode, bp->fid.unique, bp->offset.HighPart,
1736 bp->offset.LowPart, bp->dataVersion, bp->flags,
1737 bp->cmFlags, bp->refCount);
1738 WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
1740 StringCbPrintfA(output, sizeof(output), "%s - Done dumping buf_dirtyListEndp.\r\n", cookie);
1741 WriteFile(outputFile, output, (DWORD)strlen(output), &zilch, NULL);
1744 lock_ReleaseRead(&buf_globalLock);
1748 void buf_ForceTrace(BOOL flush)
1757 len = GetTempPath(sizeof(buf)-10, buf);
1758 StringCbCopyA(&buf[len], sizeof(buf)-len, "/afs-buffer.log");
1759 handle = CreateFile(buf, GENERIC_WRITE, FILE_SHARE_READ,
1760 NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
1761 if (handle == INVALID_HANDLE_VALUE) {
1762 osi_panic("Cannot create log file", __FILE__, __LINE__);
1764 osi_LogPrint(buf_logp, handle);
1766 FlushFileBuffers(handle);
1767 CloseHandle(handle);
1770 long buf_DirtyBuffersExist(cm_fid_t *fidp)
1773 afs_uint32 bcount = 0;
1776 i = BUF_FILEHASH(fidp);
1778 for (bp = cm_data.buf_fileHashTablepp[i]; bp; bp=bp->allp, bcount++) {
1779 if (!cm_FidCmp(fidp, &bp->fid) && (bp->flags & CM_BUF_DIRTY))
1786 long buf_CleanDirtyBuffers(cm_scache_t *scp)
1789 afs_uint32 bcount = 0;
1790 cm_fid_t * fidp = &scp->fid;
1792 for (bp = cm_data.buf_allp; bp; bp=bp->allp, bcount++) {
1793 if (!cm_FidCmp(fidp, &bp->fid) && (bp->flags & CM_BUF_DIRTY)) {
1795 lock_ObtainMutex(&bp->mx);
1796 bp->cmFlags &= ~CM_BUF_CMSTORING;
1797 bp->flags &= ~CM_BUF_DIRTY;
1798 bp->dirty_offset = 0;
1799 bp->dirty_length = 0;
1800 bp->flags |= CM_BUF_ERROR;
1801 bp->error = VNOVNODE;
1802 bp->dataVersion = CM_BUF_VERSION_BAD; /* bad */
1804 if (bp->flags & CM_BUF_WAITING) {
1805 osi_Log2(buf_logp, "BUF CleanDirtyBuffers Waking [scp 0x%x] bp 0x%x", scp, bp);
1806 osi_Wakeup((long) &bp);
1808 lock_ReleaseMutex(&bp->mx);