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61 #include <afsconfig.h>
62 #include "afs/param.h"
63 #if defined(AFS_CACHE_BYPASS) || defined(UKERNEL)
64 #include "afs/afs_bypasscache.h"
70 #include "afs/sysincludes.h" /* Standard vendor system headers */
71 #include "afs/afsincludes.h" /* Afs-based standard headers */
72 #include "afs/afs_stats.h" /* statistics */
73 #include "afs/nfsclient.h"
74 #include "rx/rx_globals.h"
77 #define afs_min(A,B) ((A)<(B)) ? (A) : (B)
80 /* conditional GLOCK macros */
81 #define COND_GLOCK(var) \
83 var = ISAFS_GLOCK(); \
88 #define COND_RE_GUNLOCK(var) \
95 /* conditional GUNLOCK macros */
97 #define COND_GUNLOCK(var) \
99 var = ISAFS_GLOCK(); \
104 #define COND_RE_GLOCK(var) \
111 int cache_bypass_strategy = NEVER_BYPASS_CACHE;
112 afs_size_t cache_bypass_threshold = AFS_CACHE_BYPASS_DISABLED; /* file size > threshold triggers bypass */
113 int cache_bypass_prefetch = 1; /* Should we do prefetching ? */
115 extern afs_rwlock_t afs_xcbhash;
118 * This is almost exactly like the PFlush() routine in afs_pioctl.c,
119 * but that routine is static. We are about to change a file from
120 * normal caching to bypass it's caching. Therefore, we want to
121 * free up any cache space in use by the file, and throw out any
122 * existing VM pages for the file. We keep track of the number of
123 * times we go back and forth from caching to bypass.
126 afs_TransitionToBypass(struct vcache *avc,
127 afs_ucred_t *acred, int aflags)
137 if (aflags & TRANSChangeDesiredBit)
139 if (aflags & TRANSSetManualBit)
142 #ifdef AFS_BOZONLOCK_ENV
143 afs_BozonLock(&avc->pvnLock, avc); /* Since afs_TryToSmush will do a pvn_vptrunc */
148 ObtainWriteLock(&avc->lock, 925);
150 * Someone may have beat us to doing the transition - we had no lock
151 * when we checked the flag earlier. No cause to panic, just return.
153 if (avc->cachingStates & FCSBypass)
156 /* If we never cached this, just change state */
157 if (setDesire && (!(avc->cachingStates & FCSBypass))) {
158 avc->cachingStates |= FCSBypass;
162 /* cg2v, try to store any chunks not written 20071204 */
163 if (avc->execsOrWriters > 0) {
164 struct vrequest *treq = NULL;
166 code = afs_CreateReq(&treq, acred);
168 code = afs_StoreAllSegments(avc, treq, AFS_SYNC | AFS_LASTSTORE);
169 afs_DestroyReq(treq);
174 /* also cg2v, don't dequeue the callback */
175 ObtainWriteLock(&afs_xcbhash, 956);
176 afs_DequeueCallback(avc);
177 ReleaseWriteLock(&afs_xcbhash);
179 avc->f.states &= ~(CStatd | CDirty); /* next reference will re-stat */
180 /* now find the disk cache entries */
181 afs_TryToSmush(avc, acred, 1);
182 osi_dnlc_purgedp(avc);
183 if (avc->linkData && !(avc->f.states & CCore)) {
184 afs_osi_Free(avc->linkData, strlen(avc->linkData) + 1);
185 avc->linkData = NULL;
188 avc->cachingStates |= FCSBypass; /* Set the bypass flag */
190 avc->cachingStates |= FCSDesireBypass;
192 avc->cachingStates |= FCSManuallySet;
193 avc->cachingTransitions++;
196 ReleaseWriteLock(&avc->lock);
197 #ifdef AFS_BOZONLOCK_ENV
198 afs_BozonUnlock(&avc->pvnLock, avc);
205 * This is almost exactly like the PFlush() routine in afs_pioctl.c,
206 * but that routine is static. We are about to change a file from
207 * bypassing caching to normal caching. Therefore, we want to
208 * throw out any existing VM pages for the file. We keep track of
209 * the number of times we go back and forth from caching to bypass.
212 afs_TransitionToCaching(struct vcache *avc,
222 if (aflags & TRANSChangeDesiredBit)
224 if (aflags & TRANSSetManualBit)
227 #ifdef AFS_BOZONLOCK_ENV
228 afs_BozonLock(&avc->pvnLock, avc); /* Since afs_TryToSmush will do a pvn_vptrunc */
232 ObtainWriteLock(&avc->lock, 926);
234 * Someone may have beat us to doing the transition - we had no lock
235 * when we checked the flag earlier. No cause to panic, just return.
237 if (!(avc->cachingStates & FCSBypass))
240 /* Ok, we actually do need to flush */
241 ObtainWriteLock(&afs_xcbhash, 957);
242 afs_DequeueCallback(avc);
243 avc->f.states &= ~(CStatd | CDirty); /* next reference will re-stat cache entry */
244 ReleaseWriteLock(&afs_xcbhash);
245 /* now find the disk cache entries */
246 afs_TryToSmush(avc, acred, 1);
247 osi_dnlc_purgedp(avc);
248 if (avc->linkData && !(avc->f.states & CCore)) {
249 afs_osi_Free(avc->linkData, strlen(avc->linkData) + 1);
250 avc->linkData = NULL;
253 avc->cachingStates &= ~(FCSBypass); /* Reset the bypass flag */
255 avc->cachingStates &= ~(FCSDesireBypass);
257 avc->cachingStates |= FCSManuallySet;
258 avc->cachingTransitions++;
261 ReleaseWriteLock(&avc->lock);
262 #ifdef AFS_BOZONLOCK_ENV
263 afs_BozonUnlock(&avc->pvnLock, avc);
269 /* In the case where there's an error in afs_NoCacheFetchProc or
270 * afs_PrefetchNoCache, all of the pages they've been passed need
274 typedef void * bypass_page_t;
276 #define unlock_and_release_pages(auio)
277 #define release_full_page(pp, pageoff)
280 typedef struct page * bypass_page_t;
282 #define unlock_and_release_pages(auio) \
284 struct iovec *ciov; \
287 afs_int32 iovno = 0; \
288 ciov = auio->uio_iov; \
289 iovmax = auio->uio_iovcnt - 1; \
290 pp = (bypass_page_t) ciov->iov_base; \
293 if (PageLocked(pp)) \
295 put_page(pp); /* decrement refcount */ \
300 ciov = (auio->uio_iov + iovno); \
301 pp = (bypass_page_t) ciov->iov_base; \
305 #define release_full_page(pp, pageoff) \
307 /* this is appropriate when no caller intends to unlock \
308 * and release the page */ \
309 SetPageUptodate(pp); \
313 afs_warn("afs_NoCacheFetchProc: page not locked!\n"); \
314 put_page(pp); /* decrement refcount */ \
319 afs_bypass_copy_page(bypass_page_t pp, int pageoff, struct iovec *rxiov,
320 int iovno, int iovoff, struct uio *auio, int curiov, int partial)
326 dolen = auio->uio_iov[curiov].iov_len - pageoff;
328 dolen = rxiov[iovno].iov_len - iovoff;
330 #if !defined(UKERNEL)
331 # if defined(KMAP_ATOMIC_TAKES_NO_KM_TYPE)
332 address = kmap_atomic(pp);
334 address = kmap_atomic(pp, KM_USER0);
339 memcpy(address + pageoff, (char *)(rxiov[iovno].iov_base) + iovoff, dolen);
340 #if !defined(UKERNEL)
341 # if defined(KMAP_ATOMIC_TAKES_NO_KM_TYPE)
342 kunmap_atomic(address);
344 kunmap_atomic(address, KM_USER0);
349 /* no-cache prefetch routine */
351 afs_NoCacheFetchProc(struct rx_call *acall,
354 afs_int32 release_pages,
359 int moredata, iovno, iovoff, iovmax, result, locked;
368 rxiov = osi_AllocSmallSpace(sizeof(struct iovec) * RX_MAXIOVECS);
369 ciov = auio->uio_iov;
370 pp = (bypass_page_t) ciov->iov_base;
371 iovmax = auio->uio_iovcnt - 1;
372 iovno = iovoff = result = 0;
375 COND_GUNLOCK(locked);
376 code = rx_Read(acall, (char *)&length, sizeof(afs_int32));
377 COND_RE_GLOCK(locked);
378 if (code != sizeof(afs_int32)) {
380 afs_warn("Preread error. code: %d instead of %d\n",
381 code, (int)sizeof(afs_int32));
382 unlock_and_release_pages(auio);
385 length = ntohl(length);
389 afs_warn("Preread error. Got length %d, which is greater than size %d\n",
391 unlock_and_release_pages(auio);
395 /* If we get a 0 length reply, time to cleanup and return */
397 unlock_and_release_pages(auio);
403 * The fetch protocol is extended for the AFS/DFS translator
404 * to allow multiple blocks of data, each with its own length,
405 * to be returned. As long as the top bit is set, there are more
408 * We do not do this for AFS file servers because they sometimes
409 * return large negative numbers as the transfer size.
411 if (avc->f.states & CForeign) {
412 moredata = length & 0x80000000;
413 length &= ~0x80000000;
418 for (curpage = 0; curpage <= iovmax; curpage++) {
420 /* properly, this should track uio_resid, not a fixed page size! */
421 while (pageoff < auio->uio_iov[curpage].iov_len) {
422 /* If no more iovs, issue new read. */
424 COND_GUNLOCK(locked);
425 bytes = rx_Readv(acall, rxiov, &nio, RX_MAXIOVECS, length);
426 COND_RE_GLOCK(locked);
428 afs_warn("afs_NoCacheFetchProc: rx_Read error. Return code was %d\n", bytes);
430 unlock_and_release_pages(auio);
432 } else if (bytes == 0) {
433 /* we failed to read the full length */
435 afs_warn("afs_NoCacheFetchProc: rx_Read returned zero. Aborting.\n");
436 unlock_and_release_pages(auio);
440 auio->uio_resid -= bytes;
443 pp = (bypass_page_t)auio->uio_iov[curpage].iov_base;
444 if (pageoff + (rxiov[iovno].iov_len - iovoff) <= auio->uio_iov[curpage].iov_len) {
445 /* Copy entire (or rest of) current iovec into current page */
447 afs_bypass_copy_page(pp, pageoff, rxiov, iovno, iovoff, auio, curpage, 0);
448 length -= (rxiov[iovno].iov_len - iovoff);
449 pageoff += rxiov[iovno].iov_len - iovoff;
453 /* Copy only what's needed to fill current page */
455 afs_bypass_copy_page(pp, pageoff, rxiov, iovno, iovoff, auio, curpage, 1);
456 length -= (auio->uio_iov[curpage].iov_len - pageoff);
457 iovoff += auio->uio_iov[curpage].iov_len - pageoff;
458 pageoff = auio->uio_iov[curpage].iov_len;
461 /* we filled a page, or this is the last page. conditionally release it */
462 if (pp && ((pageoff == auio->uio_iov[curpage].iov_len &&
463 release_pages) || (length == 0 && iovno >= nio)))
464 release_full_page(pp, pageoff);
466 if (length == 0 && iovno >= nio)
473 osi_FreeSmallSpace(rxiov);
478 /* dispatch a no-cache read request */
480 afs_ReadNoCache(struct vcache *avc,
481 struct nocache_read_request *bparms,
486 struct brequest *breq;
487 struct vrequest *areq = NULL;
491 afs_warn("afs_ReadNoCache VCache Error!\n");
496 /* the receiver will free areq */
497 code = afs_CreateReq(&areq, acred);
499 afs_warn("afs_ReadNoCache afs_CreateReq error!\n");
501 code = afs_VerifyVCache(avc, areq);
503 afs_warn("afs_ReadNoCache Failed to verify VCache!\n");
509 code = afs_CheckCode(code, areq, 11); /* failed to get it */
515 /* and queue this one */
519 breq = afs_BQueue(BOP_FETCH_NOCACHE, avc, B_DONTWAIT, 0, acred, 1, 1,
520 bparms, (void *)0, (void *)0);
525 afs_osi_Wait(10 * bcnt, 0, 0);
537 /* If there's a problem before we queue the request, we need to
538 * do everything that would normally happen when the request was
539 * processed, like unlocking the pages and freeing memory.
541 unlock_and_release_pages(bparms->auio);
543 afs_DestroyReq(areq);
545 osi_Free(bparms->auio->uio_iov,
546 bparms->auio->uio_iovcnt * sizeof(struct iovec));
547 osi_Free(bparms->auio, sizeof(struct uio));
548 osi_Free(bparms, sizeof(struct nocache_read_request));
553 /* Cannot have static linkage--called from BPrefetch (afs_daemons) */
555 afs_PrefetchNoCache(struct vcache *avc,
557 struct nocache_read_request *bparms)
561 struct iovec *iovecp;
563 struct vrequest *areq;
565 struct rx_connection *rxconn;
566 #ifdef AFS_64BIT_CLIENT
567 afs_int32 length_hi, bytes, locked;
571 struct rx_call *tcall;
573 struct AFSVolSync tsync;
574 struct AFSFetchStatus OutStatus;
575 struct AFSCallBack CallBack;
577 struct tlocal1 *tcallspec;
582 iovecp = auio->uio_iov;
585 tcallspec = osi_Alloc(sizeof(struct tlocal1));
587 tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK /* ignored */, &rxconn);
589 avc->callback = tc->parent->srvr->server;
590 tcall = rx_NewCall(rxconn);
591 #ifdef AFS_64BIT_CLIENT
592 if (!afs_serverHasNo64Bit(tc)) {
593 code = StartRXAFS_FetchData64(tcall,
594 (struct AFSFid *) &avc->f.fid.Fid,
598 COND_GUNLOCK(locked);
599 bytes = rx_Read(tcall, (char *)&length_hi,
601 COND_RE_GLOCK(locked);
603 if (bytes != sizeof(afs_int32)) {
605 COND_GUNLOCK(locked);
606 code = rx_EndCall(tcall, RX_PROTOCOL_ERROR);
607 COND_RE_GLOCK(locked);
611 } /* afs_serverHasNo64Bit */
612 if (code == RXGEN_OPCODE || afs_serverHasNo64Bit(tc)) {
613 if (auio->uio_offset > 0x7FFFFFFF) {
617 pos = auio->uio_offset;
618 COND_GUNLOCK(locked);
620 tcall = rx_NewCall(rxconn);
621 code = StartRXAFS_FetchData(tcall,
622 (struct AFSFid *) &avc->f.fid.Fid,
623 pos, bparms->length);
624 COND_RE_GLOCK(locked);
626 afs_serverSetNo64Bit(tc);
629 code = StartRXAFS_FetchData(tcall,
630 (struct AFSFid *) &avc->f.fid.Fid,
631 auio->uio_offset, bparms->length);
634 code = afs_NoCacheFetchProc(tcall, avc, auio,
635 1 /* release_pages */,
638 afs_warn("BYPASS: StartRXAFS_FetchData failed: %d\n", code);
639 unlock_and_release_pages(auio);
643 code = EndRXAFS_FetchData(tcall, &tcallspec->OutStatus,
644 &tcallspec->CallBack,
647 afs_warn("BYPASS: NoCacheFetchProc failed: %d\n", code);
649 code = rx_EndCall(tcall, code);
651 afs_warn("BYPASS: No connection.\n");
653 unlock_and_release_pages(auio);
656 } while (afs_Analyze(tc, rxconn, code, &avc->f.fid, areq,
657 AFS_STATS_FS_RPCIDX_FETCHDATA,
661 * Copy appropriate fields into vcache
665 afs_ProcessFS(avc, &tcallspec->OutStatus, areq);
667 osi_Free(areq, sizeof(struct vrequest));
668 osi_Free(tcallspec, sizeof(struct tlocal1));
669 osi_Free(bparms, sizeof(struct nocache_read_request));
671 /* in UKERNEL, the "pages" are passed in */
672 osi_Free(iovecp, auio->uio_iovcnt * sizeof(struct iovec));
673 osi_Free(auio, sizeof(struct uio));