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40 * pertaining to the use or distribution of this software
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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(struct vcache *avc,
135 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(struct vcache *avc,
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_and_release_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)) \
284 put_page(pp); /* decrement refcount */ \
288 ciov = (auio->uio_iov + iovno); \
289 pp = (struct page*) ciov->iov_base; \
291 afs_warn("Pages Unlocked.\n"); \
295 #define unlock_and_release_pages(auio) \
298 #error AFS_CACHE_BYPASS not implemented on this platform
302 /* no-cache prefetch routine */
304 afs_NoCacheFetchProc(struct rx_call *acall,
307 afs_int32 release_pages,
313 int moredata, iovno, iovoff, iovmax, clen, result, locked;
317 #ifdef AFS_KMAP_ATOMIC
318 char *page_buffer = osi_Alloc(PAGE_SIZE);
320 char *page_buffer = NULL;
323 ciov = auio->uio_iov;
324 pp = (struct page*) ciov->iov_base;
325 iovmax = auio->uio_iovcnt - 1;
326 iovno = iovoff = result = 0;
329 COND_GUNLOCK(locked);
330 code = rx_Read(acall, (char *)&length, sizeof(afs_int32));
331 COND_RE_GLOCK(locked);
333 if (code != sizeof(afs_int32)) {
335 afs_warn("Preread error. code: %d instead of %d\n",
336 code, (int)sizeof(afs_int32));
337 unlock_and_release_pages(auio);
340 length = ntohl(length);
344 afs_warn("Preread error. Got length %d, which is greater than size %d\n",
346 unlock_and_release_pages(auio);
351 * The fetch protocol is extended for the AFS/DFS translator
352 * to allow multiple blocks of data, each with its own length,
353 * to be returned. As long as the top bit is set, there are more
356 * We do not do this for AFS file servers because they sometimes
357 * return large negative numbers as the transfer size.
359 if (avc->f.states & CForeign) {
360 moredata = length & 0x80000000;
361 length &= ~0x80000000;
368 clen = ciov->iov_len - iovoff;
369 tlen = afs_min(length, clen);
370 #ifdef AFS_LINUX24_ENV
371 #ifndef AFS_KMAP_ATOMIC
375 /* rx doesn't provide an interface to simply advance
376 or consume n bytes. for now, allocate a PAGE_SIZE
377 region of memory to receive bytes in the case that
378 there were holes in readpages */
379 if(page_buffer == NULL)
380 page_buffer = osi_Alloc(PAGE_SIZE);
381 address = page_buffer;
384 address = page_buffer;
388 #error AFS_CACHE_BYPASS not implemented on this platform
391 COND_GUNLOCK(locked);
392 code = rx_Read(acall, address, tlen);
393 COND_RE_GLOCK(locked);
396 afs_warn("afs_NoCacheFetchProc: rx_Read error. Return code was %d\n", code);
398 unlock_and_release_pages(auio);
400 } else if (code == 0) {
402 afs_warn("afs_NoCacheFetchProc: rx_Read returned zero. Aborting.\n");
403 unlock_and_release_pages(auio);
413 #ifdef AFS_LINUX24_ENV
414 #ifdef AFS_KMAP_ATOMIC
416 address = kmap_atomic(pp, KM_USER0);
417 memcpy(address, page_buffer, PAGE_SIZE);
418 kunmap_atomic(address, KM_USER0);
423 #error AFS_CACHE_BYPASS not implemented on this platform
425 #endif /* LINUX 24 */
426 /* we filled a page, conditionally release it */
427 if (release_pages && ciov->iov_base) {
428 /* this is appropriate when no caller intends to unlock
429 * and release the page */
430 #ifdef AFS_LINUX24_ENV
435 afs_warn("afs_NoCacheFetchProc: page not locked at iovno %d!\n", iovno);
436 put_page(pp); /* decrement refcount */
437 #ifndef AFS_KMAP_ATOMIC
442 #error AFS_CACHE_BYPASS not implemented on this platform
446 /* and carry uio_iov */
451 ciov = (auio->uio_iov + iovno);
452 pp = (struct page*) ciov->iov_base;
460 osi_Free(page_buffer, PAGE_SIZE);
465 /* dispatch a no-cache read request */
467 afs_ReadNoCache(struct vcache *avc,
468 struct nocache_read_request *bparms,
473 struct brequest *breq;
474 struct vrequest *areq;
476 /* the reciever will free this */
477 areq = osi_Alloc(sizeof(struct vrequest));
479 if (avc && avc->vc_error) {
481 afs_warn("afs_ReadNoCache VCache Error!\n");
484 if ((code = afs_InitReq(areq, acred))) {
485 afs_warn("afs_ReadNoCache afs_InitReq error!\n");
490 code = afs_VerifyVCache(avc, areq);
494 code = afs_CheckCode(code, areq, 11); /* failed to get it */
495 afs_warn("afs_ReadNoCache Failed to verify VCache!\n");
501 /* and queue this one */
505 breq = afs_BQueue(BOP_FETCH_NOCACHE, avc, B_DONTWAIT, 0, acred, 1, 1,
506 bparms, (void *)0, (void *)0);
511 afs_osi_Wait(10 * bcnt, 0, 0);
523 /* If there's a problem before we queue the request, we need to
524 * do everything that would normally happen when the request was
525 * processed, like unlocking the pages and freeing memory.
527 #ifdef AFS_LINUX24_ENV
528 unlock_and_release_pages(bparms->auio);
531 #error AFS_CACHE_BYPASS not implemented on this platform
534 osi_Free(areq, sizeof(struct vrequest));
535 osi_Free(bparms->auio->uio_iov,
536 bparms->auio->uio_iovcnt * sizeof(struct iovec));
537 osi_Free(bparms->auio, sizeof(uio_t));
538 osi_Free(bparms, sizeof(struct nocache_read_request));
543 /* Cannot have static linkage--called from BPrefetch (afs_daemons) */
545 afs_PrefetchNoCache(struct vcache *avc,
547 struct nocache_read_request *bparms)
550 struct iovec *iovecp;
551 struct vrequest *areq;
553 #ifdef AFS_64BIT_CLIENT
554 afs_int32 length_hi, bytes, locked;
559 struct rx_call *tcall;
561 struct AFSVolSync tsync;
562 struct AFSFetchStatus OutStatus;
563 struct AFSCallBack CallBack;
565 struct tlocal1 *tcallspec;
569 iovecp = auio->uio_iov;
571 tcallspec = (struct tlocal1 *) osi_Alloc(sizeof(struct tlocal1));
573 tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK /* ignored */);
575 avc->callback = tc->srvr->server;
577 tcall = rx_NewCall(tc->id);
578 #ifdef AFS_64BIT_CLIENT
579 if (!afs_serverHasNo64Bit(tc)) {
580 code = StartRXAFS_FetchData64(tcall,
581 (struct AFSFid *) &avc->f.fid.Fid,
585 COND_GUNLOCK(locked);
586 bytes = rx_Read(tcall, (char *)&length_hi,
588 COND_RE_GLOCK(locked);
590 if (bytes != sizeof(afs_int32)) {
592 code = rx_Error(tcall);
593 COND_GUNLOCK(locked);
594 code = rx_EndCall(tcall, code);
595 COND_RE_GLOCK(locked);
599 } /* afs_serverHasNo64Bit */
600 if (code == RXGEN_OPCODE || afs_serverHasNo64Bit(tc)) {
601 if (auio->uio_offset > 0x7FFFFFFF) {
605 pos = auio->uio_offset;
606 COND_GUNLOCK(locked);
608 tcall = rx_NewCall(tc->id);
609 code = StartRXAFS_FetchData(tcall,
610 (struct AFSFid *) &avc->f.fid.Fid,
611 pos, bparms->length);
612 COND_RE_GLOCK(locked);
614 afs_serverSetNo64Bit(tc);
617 code = StartRXAFS_FetchData(tcall,
618 (struct AFSFid *) &avc->f.fid.Fid,
619 auio->uio_offset, bparms->length);
622 code = afs_NoCacheFetchProc(tcall, avc, auio,
623 1 /* release_pages */,
626 afs_warn("BYPASS: StartRXAFS_FetchData failed: %d\n", code);
627 unlock_and_release_pages(auio);
631 code = EndRXAFS_FetchData(tcall, &tcallspec->OutStatus,
632 &tcallspec->CallBack,
635 afs_warn("BYPASS: NoCacheFetchProc failed: %d\n", code);
637 code = rx_EndCall(tcall, code);
639 afs_warn("BYPASS: No connection.\n");
641 #ifdef AFS_LINUX24_ENV
642 unlock_and_release_pages(auio);
645 #error AFS_CACHE_BYPASS not implemented on this platform
650 } while (afs_Analyze(tc, code, &avc->f.fid, areq,
651 AFS_STATS_FS_RPCIDX_FETCHDATA,
655 * Copy appropriate fields into vcache
658 afs_ProcessFS(avc, &tcallspec->OutStatus, areq);
660 osi_Free(areq, sizeof(struct vrequest));
661 osi_Free(tcallspec, sizeof(struct tlocal1));
662 osi_Free(iovecp, auio->uio_iovcnt * sizeof(struct iovec));
663 osi_Free(bparms, sizeof(struct nocache_read_request));
664 osi_Free(auio, sizeof(uio_t));
668 #endif /* AFS_CACHE_BYPASS */