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37 * and redistribute this software and such derivative works
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39 * Corporation is not used in any advertising or publicity
40 * pertaining to the use or distribution of this software
41 * without specific, written prior authorization. If the
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61 #include <afsconfig.h>
62 #include "afs/param.h"
64 #if defined(AFS_CACHE_BYPASS)
66 #include "afs/afs_bypasscache.h"
72 #include "afs/sysincludes.h" /* Standard vendor system headers */
73 #include "afs/afsincludes.h" /* Afs-based standard headers */
74 #include "afs/afs_stats.h" /* statistics */
75 #include "afs/nfsclient.h"
76 #include "rx/rx_globals.h"
78 #if defined(AFS_LINUX26_ENV)
79 #define LockPage(pp) lock_page(pp)
80 #define UnlockPage(pp) unlock_page(pp)
82 #define AFS_KMAP_ATOMIC
85 #define afs_min(A,B) ((A)<(B)) ? (A) : (B)
88 /* conditional GLOCK macros */
89 #define COND_GLOCK(var) \
91 var = ISAFS_GLOCK(); \
96 #define COND_RE_GUNLOCK(var) \
103 /* conditional GUNLOCK macros */
105 #define COND_GUNLOCK(var) \
107 var = ISAFS_GLOCK(); \
112 #define COND_RE_GLOCK(var) \
119 int cache_bypass_strategy = NEVER_BYPASS_CACHE;
120 int cache_bypass_threshold = AFS_CACHE_BYPASS_DISABLED; /* file size > threshold triggers bypass */
121 int cache_bypass_prefetch = 1; /* Should we do prefetching ? */
123 extern afs_rwlock_t afs_xcbhash;
126 * This is almost exactly like the PFlush() routine in afs_pioctl.c,
127 * but that routine is static. We are about to change a file from
128 * normal caching to bypass it's caching. Therefore, we want to
129 * free up any cache space in use by the file, and throw out any
130 * existing VM pages for the file. We keep track of the number of
131 * times we go back and forth from caching to bypass.
134 afs_TransitionToBypass(register struct vcache *avc,
135 register afs_ucred_t *acred, int aflags)
139 struct vrequest treq;
146 if (avc->f.states & FCSBypass)
147 osi_Panic("afs_TransitionToBypass: illegal transition to bypass--already FCSBypass\n");
149 if (aflags & TRANSChangeDesiredBit)
151 if (aflags & TRANSSetManualBit)
154 #ifdef AFS_BOZONLOCK_ENV
155 afs_BozonLock(&avc->pvnLock, avc); /* Since afs_TryToSmush will do a pvn_vptrunc */
159 ObtainWriteLock(&avc->lock, 925);
161 /* If we never cached this, just change state */
162 if (setDesire && (!avc->cachingStates & FCSBypass)) {
163 avc->f.states |= FCSBypass;
167 /* cg2v, try to store any chunks not written 20071204 */
168 if (avc->execsOrWriters > 0) {
169 code = afs_InitReq(&treq, acred);
171 code = afs_StoreAllSegments(avc, &treq, AFS_SYNC | AFS_LASTSTORE);
175 /* also cg2v, don't dequeue the callback */
176 ObtainWriteLock(&afs_xcbhash, 956);
177 afs_DequeueCallback(avc);
178 ReleaseWriteLock(&afs_xcbhash);
180 avc->f.states &= ~(CStatd | CDirty); /* next reference will re-stat */
181 /* now find the disk cache entries */
182 afs_TryToSmush(avc, acred, 1);
183 osi_dnlc_purgedp(avc);
184 if (avc->linkData && !(avc->f.states & CCore)) {
185 afs_osi_Free(avc->linkData, strlen(avc->linkData) + 1);
186 avc->linkData = NULL;
189 avc->cachingStates |= FCSBypass; /* Set the bypass flag */
191 avc->cachingStates |= FCSDesireBypass;
193 avc->cachingStates |= FCSManuallySet;
194 avc->cachingTransitions++;
197 ReleaseWriteLock(&avc->lock);
198 #ifdef AFS_BOZONLOCK_ENV
199 afs_BozonUnlock(&avc->pvnLock, avc);
206 * This is almost exactly like the PFlush() routine in afs_pioctl.c,
207 * but that routine is static. We are about to change a file from
208 * bypassing caching to normal caching. Therefore, we want to
209 * throw out any existing VM pages for the file. We keep track of
210 * the number of times we go back and forth from caching to bypass.
213 afs_TransitionToCaching(register struct vcache *avc,
214 register afs_ucred_t *acred,
223 if (!avc->f.states & FCSBypass)
224 osi_Panic("afs_TransitionToCaching: illegal transition to caching--already caching\n");
226 if (aflags & TRANSChangeDesiredBit)
228 if (aflags & TRANSSetManualBit)
231 #ifdef AFS_BOZONLOCK_ENV
232 afs_BozonLock(&avc->pvnLock, avc); /* Since afs_TryToSmush will do a pvn_vptrunc */
236 ObtainWriteLock(&avc->lock, 926);
238 /* Ok, we actually do need to flush */
239 ObtainWriteLock(&afs_xcbhash, 957);
240 afs_DequeueCallback(avc);
241 avc->f.states &= ~(CStatd | CDirty); /* next reference will re-stat cache entry */
242 ReleaseWriteLock(&afs_xcbhash);
243 /* now find the disk cache entries */
244 afs_TryToSmush(avc, acred, 1);
245 osi_dnlc_purgedp(avc);
246 if (avc->linkData && !(avc->f.states & CCore)) {
247 afs_osi_Free(avc->linkData, strlen(avc->linkData) + 1);
248 avc->linkData = NULL;
251 avc->cachingStates &= ~(FCSBypass); /* Reset the bypass flag */
253 avc->cachingStates &= ~(FCSDesireBypass);
255 avc->cachingStates |= FCSManuallySet;
256 avc->cachingTransitions++;
258 ReleaseWriteLock(&avc->lock);
259 #ifdef AFS_BOZONLOCK_ENV
260 afs_BozonUnlock(&avc->pvnLock, avc);
266 /* In the case where there's an error in afs_NoCacheFetchProc or
267 * afs_PrefetchNoCache, all of the pages they've been passed need
270 #if defined(AFS_LINUX24_ENV)
271 #define unlock_pages(auio) \
273 struct iovec *ciov; \
276 afs_int32 iovno = 0; \
277 ciov = auio->uio_iov; \
278 iovmax = auio->uio_iovcnt - 1; \
279 pp = (struct page*) ciov->iov_base; \
280 afs_warn("BYPASS: Unlocking pages..."); \
282 if(pp != NULL && PageLocked(pp)) \
287 ciov = (auio->uio_iov + iovno); \
288 pp = (struct page*) ciov->iov_base; \
290 afs_warn("Pages Unlocked.\n"); \
294 #define unlock_pages(auio) \
297 #error AFS_CACHE_BYPASS not implemented on this platform
301 /* no-cache prefetch routine */
303 afs_NoCacheFetchProc(register struct rx_call *acall,
304 register struct vcache *avc,
305 register uio_t *auio,
306 afs_int32 release_pages)
311 int moredata, iovno, iovoff, iovmax, clen, result, locked;
315 #ifdef AFS_KMAP_ATOMIC
316 char *page_buffer = osi_Alloc(PAGE_SIZE);
318 char *page_buffer = NULL;
321 ciov = auio->uio_iov;
322 pp = (struct page*) ciov->iov_base;
323 iovmax = auio->uio_iovcnt - 1;
324 iovno = iovoff = result = 0;
327 COND_GUNLOCK(locked);
328 code = rx_Read(acall, (char *)&length, sizeof(afs_int32));
329 COND_RE_GLOCK(locked);
331 if (code != sizeof(afs_int32)) {
333 afs_warn("Preread error. code: %d instead of %d\n",
334 code, sizeof(afs_int32));
338 length = ntohl(length);
341 * The fetch protocol is extended for the AFS/DFS translator
342 * to allow multiple blocks of data, each with its own length,
343 * to be returned. As long as the top bit is set, there are more
346 * We do not do this for AFS file servers because they sometimes
347 * return large negative numbers as the transfer size.
349 if (avc->f.states & CForeign) {
350 moredata = length & 0x80000000;
351 length &= ~0x80000000;
358 clen = ciov->iov_len - iovoff;
359 tlen = afs_min(length, clen);
360 #ifdef AFS_LINUX24_ENV
361 #ifndef AFS_KMAP_ATOMIC
365 /* rx doesn't provide an interface to simply advance
366 or consume n bytes. for now, allocate a PAGE_SIZE
367 region of memory to receive bytes in the case that
368 there were holes in readpages */
369 if(page_buffer == NULL)
370 page_buffer = osi_Alloc(PAGE_SIZE);
371 address = page_buffer;
374 address = page_buffer;
378 #error AFS_CACHE_BYPASS not implemented on this platform
381 COND_GUNLOCK(locked);
382 code = rx_Read(acall, address, tlen);
383 COND_RE_GLOCK(locked);
386 afs_warn("afs_NoCacheFetchProc: rx_Read error. Return code was %d\n", code);
390 } else if (code == 0) {
392 afs_warn("afs_NoCacheFetchProc: rx_Read returned zero. Aborting.\n");
403 #ifdef AFS_LINUX24_ENV
404 #ifdef AFS_KMAP_ATOMIC
406 address = kmap_atomic(pp, KM_USER0);
407 memcpy(address, page_buffer, PAGE_SIZE);
408 kunmap_atomic(address, KM_USER0);
413 #error AFS_CACHE_BYPASS not implemented on this platform
415 #endif /* LINUX 24 */
416 /* we filled a page, conditionally release it */
417 if (release_pages && ciov->iov_base) {
418 /* this is appropriate when no caller intends to unlock
419 * and release the page */
420 #ifdef AFS_LINUX24_ENV
425 afs_warn("afs_NoCacheFetchProc: page not locked at iovno %d!\n", iovno);
426 #ifndef AFS_KMAP_ATOMIC
431 #error AFS_CACHE_BYPASS not implemented on this platform
435 /* and carry uio_iov */
440 ciov = (auio->uio_iov + iovno);
441 pp = (struct page*) ciov->iov_base;
449 osi_Free(page_buffer, PAGE_SIZE);
454 /* dispatch a no-cache read request */
456 afs_ReadNoCache(register struct vcache *avc,
457 register struct nocache_read_request *bparms,
462 struct brequest *breq;
463 struct vrequest *areq;
465 /* the reciever will free this */
466 areq = osi_Alloc(sizeof(struct vrequest));
468 if (avc && avc->vc_error) {
470 afs_warn("afs_ReadNoCache VCache Error!\n");
473 if ((code = afs_InitReq(areq, acred))) {
474 afs_warn("afs_ReadNoCache afs_InitReq error!\n");
479 code = afs_VerifyVCache(avc, areq);
483 code = afs_CheckCode(code, areq, 11); /* failed to get it */
484 afs_warn("afs_ReadNoCache Failed to verify VCache!\n");
490 /* and queue this one */
494 breq = afs_BQueue(BOP_FETCH_NOCACHE, avc, B_DONTWAIT, 0, acred, 1, 1,
500 afs_osi_Wait(10 * bcnt, 0, 0);
512 /* If there's a problem before we queue the request, we need to
513 * do everything that would normally happen when the request was
514 * processed, like unlocking the pages and freeing memory.
516 #ifdef AFS_LINUX24_ENV
517 unlock_pages(bparms->auio);
520 #error AFS_CACHE_BYPASS not implemented on this platform
523 osi_Free(areq, sizeof(struct vrequest));
524 osi_Free(bparms->auio->uio_iov,
525 bparms->auio->uio_iovcnt * sizeof(struct iovec));
526 osi_Free(bparms->auio, sizeof(uio_t));
527 osi_Free(bparms, sizeof(struct nocache_read_request));
532 /* Cannot have static linkage--called from BPrefetch (afs_daemons) */
534 afs_PrefetchNoCache(register struct vcache *avc,
535 register afs_ucred_t *acred,
536 register struct nocache_read_request *bparms)
539 struct iovec *iovecp;
540 struct vrequest *areq;
541 afs_int32 code, length_hi, bytes, locked;
543 register struct afs_conn *tc;
545 struct rx_call *tcall;
547 struct AFSVolSync tsync;
548 struct AFSFetchStatus OutStatus;
549 struct AFSCallBack CallBack;
551 struct tlocal1 *tcallspec;
555 iovecp = auio->uio_iov;
557 tcallspec = (struct tlocal1 *) osi_Alloc(sizeof(struct tlocal1));
559 tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK /* ignored */);
561 avc->callback = tc->srvr->server;
563 tcall = rx_NewCall(tc->id);
564 #ifdef AFS_64BIT_CLIENT
565 if (!afs_serverHasNo64Bit(tc)) {
566 code = StartRXAFS_FetchData64(tcall,
567 (struct AFSFid *) &avc->f.fid.Fid,
571 COND_GUNLOCK(locked);
572 bytes = rx_Read(tcall, (char *)&length_hi,
574 COND_RE_GLOCK(locked);
576 if (bytes != sizeof(afs_int32)) {
578 code = rx_Error(tcall);
579 COND_GUNLOCK(locked);
580 code = rx_EndCall(tcall, code);
581 COND_RE_GLOCK(locked);
585 if (code == RXGEN_OPCODE || afs_serverHasNo64Bit(tc)) {
586 if (auio->uio_offset > 0x7FFFFFFF) {
590 pos = auio->uio_offset;
591 COND_GUNLOCK(locked);
593 tcall = rx_NewCall(tc->id);
594 code = StartRXAFS_FetchData(tcall,
595 (struct AFSFid *) &avc->f.fid.Fid,
596 pos, bparms->length);
597 COND_RE_GLOCK(locked);
599 afs_serverSetNo64Bit(tc);
601 } /* afs_serverHasNo64Bit */
603 code = StartRXAFS_FetchData(tcall,
604 (struct AFSFid *) &avc->f.fid.Fid,
605 auio->uio_offset, bparms->length);
608 code = afs_NoCacheFetchProc(tcall, avc, auio,
609 1 /* release_pages */);
611 afs_warn("BYPASS: StartRXAFS_FetchData failed: %d\n", code);
616 code = EndRXAFS_FetchData(tcall, &tcallspec->OutStatus,
617 &tcallspec->CallBack,
620 afs_warn("BYPASS: NoCacheFetchProc failed: %d\n", code);
622 code = rx_EndCall(tcall, code);
624 afs_warn("BYPASS: No connection.\n");
626 #ifdef AFS_LINUX24_ENV
630 #error AFS_CACHE_BYPASS not implemented on this platform
635 } while (afs_Analyze(tc, code, &avc->f.fid, areq,
636 AFS_STATS_FS_RPCIDX_FETCHDATA,
640 * Copy appropriate fields into vcache
643 afs_ProcessFS(avc, &tcallspec->OutStatus, areq);
645 osi_Free(areq, sizeof(struct vrequest));
646 osi_Free(tcallspec, sizeof(struct tlocal1));
647 osi_Free(iovecp, auio->uio_iovcnt * sizeof(struct iovec));
648 osi_Free(bparms, sizeof(struct nocache_read_request));
649 osi_Free(auio, sizeof(uio_t));
653 #endif /* AFS_CACHE_BYPASS */