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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)
131 struct vrequest treq;
138 if (aflags & TRANSChangeDesiredBit)
140 if (aflags & TRANSSetManualBit)
143 #ifdef AFS_BOZONLOCK_ENV
144 afs_BozonLock(&avc->pvnLock, avc); /* Since afs_TryToSmush will do a pvn_vptrunc */
149 ObtainWriteLock(&avc->lock, 925);
151 * Someone may have beat us to doing the transition - we had no lock
152 * when we checked the flag earlier. No cause to panic, just return.
154 if (avc->cachingStates & FCSBypass)
157 /* If we never cached this, just change state */
158 if (setDesire && (!(avc->cachingStates & FCSBypass))) {
159 avc->cachingStates |= FCSBypass;
163 /* cg2v, try to store any chunks not written 20071204 */
164 if (avc->execsOrWriters > 0) {
165 code = afs_InitReq(&treq, acred);
167 code = afs_StoreAllSegments(avc, &treq, AFS_SYNC | AFS_LASTSTORE);
171 /* also cg2v, don't dequeue the callback */
172 ObtainWriteLock(&afs_xcbhash, 956);
173 afs_DequeueCallback(avc);
174 ReleaseWriteLock(&afs_xcbhash);
176 avc->f.states &= ~(CStatd | CDirty); /* next reference will re-stat */
177 /* now find the disk cache entries */
178 afs_TryToSmush(avc, acred, 1);
179 osi_dnlc_purgedp(avc);
180 if (avc->linkData && !(avc->f.states & CCore)) {
181 afs_osi_Free(avc->linkData, strlen(avc->linkData) + 1);
182 avc->linkData = NULL;
185 avc->cachingStates |= FCSBypass; /* Set the bypass flag */
187 avc->cachingStates |= FCSDesireBypass;
189 avc->cachingStates |= FCSManuallySet;
190 avc->cachingTransitions++;
193 ReleaseWriteLock(&avc->lock);
194 #ifdef AFS_BOZONLOCK_ENV
195 afs_BozonUnlock(&avc->pvnLock, avc);
202 * This is almost exactly like the PFlush() routine in afs_pioctl.c,
203 * but that routine is static. We are about to change a file from
204 * bypassing caching to normal caching. Therefore, we want to
205 * throw out any existing VM pages for the file. We keep track of
206 * the number of times we go back and forth from caching to bypass.
209 afs_TransitionToCaching(struct vcache *avc,
219 if (aflags & TRANSChangeDesiredBit)
221 if (aflags & TRANSSetManualBit)
224 #ifdef AFS_BOZONLOCK_ENV
225 afs_BozonLock(&avc->pvnLock, avc); /* Since afs_TryToSmush will do a pvn_vptrunc */
229 ObtainWriteLock(&avc->lock, 926);
231 * Someone may have beat us to doing the transition - we had no lock
232 * when we checked the flag earlier. No cause to panic, just return.
234 if (!(avc->cachingStates & FCSBypass))
237 /* Ok, we actually do need to flush */
238 ObtainWriteLock(&afs_xcbhash, 957);
239 afs_DequeueCallback(avc);
240 avc->f.states &= ~(CStatd | CDirty); /* next reference will re-stat cache entry */
241 ReleaseWriteLock(&afs_xcbhash);
242 /* now find the disk cache entries */
243 afs_TryToSmush(avc, acred, 1);
244 osi_dnlc_purgedp(avc);
245 if (avc->linkData && !(avc->f.states & CCore)) {
246 afs_osi_Free(avc->linkData, strlen(avc->linkData) + 1);
247 avc->linkData = NULL;
250 avc->cachingStates &= ~(FCSBypass); /* Reset the bypass flag */
252 avc->cachingStates &= ~(FCSDesireBypass);
254 avc->cachingStates |= FCSManuallySet;
255 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
271 typedef void * bypass_page_t;
273 #define unlock_and_release_pages(auio)
274 #define release_full_page(pp, pageoff)
277 typedef struct page * bypass_page_t;
279 #define unlock_and_release_pages(auio) \
281 struct iovec *ciov; \
284 afs_int32 iovno = 0; \
285 ciov = auio->uio_iov; \
286 iovmax = auio->uio_iovcnt - 1; \
287 pp = (bypass_page_t) ciov->iov_base; \
290 if (PageLocked(pp)) \
292 put_page(pp); /* decrement refcount */ \
297 ciov = (auio->uio_iov + iovno); \
298 pp = (bypass_page_t) ciov->iov_base; \
302 #define release_full_page(pp, pageoff) \
304 /* this is appropriate when no caller intends to unlock \
305 * and release the page */ \
306 SetPageUptodate(pp); \
310 afs_warn("afs_NoCacheFetchProc: page not locked!\n"); \
311 put_page(pp); /* decrement refcount */ \
316 afs_bypass_copy_page(bypass_page_t pp, int pageoff, struct iovec *rxiov,
317 int iovno, int iovoff, struct uio *auio, int curiov, int partial)
323 dolen = auio->uio_iov[curiov].iov_len - pageoff;
325 dolen = rxiov[iovno].iov_len - iovoff;
327 #if !defined(UKERNEL)
328 # if defined(KMAP_ATOMIC_TAKES_NO_KM_TYPE)
329 address = kmap_atomic(pp);
331 address = kmap_atomic(pp, KM_USER0);
336 memcpy(address + pageoff, (char *)(rxiov[iovno].iov_base) + iovoff, dolen);
337 #if !defined(UKERNEL)
338 # if defined(KMAP_ATOMIC_TAKES_NO_KM_TYPE)
339 kunmap_atomic(address);
341 kunmap_atomic(address, KM_USER0);
346 /* no-cache prefetch routine */
348 afs_NoCacheFetchProc(struct rx_call *acall,
351 afs_int32 release_pages,
356 int moredata, iovno, iovoff, iovmax, result, locked;
365 rxiov = osi_AllocSmallSpace(sizeof(struct iovec) * RX_MAXIOVECS);
366 ciov = auio->uio_iov;
367 pp = (bypass_page_t) ciov->iov_base;
368 iovmax = auio->uio_iovcnt - 1;
369 iovno = iovoff = result = 0;
372 COND_GUNLOCK(locked);
373 code = rx_Read(acall, (char *)&length, sizeof(afs_int32));
374 COND_RE_GLOCK(locked);
375 if (code != sizeof(afs_int32)) {
377 afs_warn("Preread error. code: %d instead of %d\n",
378 code, (int)sizeof(afs_int32));
379 unlock_and_release_pages(auio);
382 length = ntohl(length);
386 afs_warn("Preread error. Got length %d, which is greater than size %d\n",
388 unlock_and_release_pages(auio);
392 /* If we get a 0 length reply, time to cleanup and return */
394 unlock_and_release_pages(auio);
400 * The fetch protocol is extended for the AFS/DFS translator
401 * to allow multiple blocks of data, each with its own length,
402 * to be returned. As long as the top bit is set, there are more
405 * We do not do this for AFS file servers because they sometimes
406 * return large negative numbers as the transfer size.
408 if (avc->f.states & CForeign) {
409 moredata = length & 0x80000000;
410 length &= ~0x80000000;
415 for (curpage = 0; curpage <= iovmax; curpage++) {
417 /* properly, this should track uio_resid, not a fixed page size! */
418 while (pageoff < auio->uio_iov[curpage].iov_len) {
419 /* If no more iovs, issue new read. */
421 COND_GUNLOCK(locked);
422 bytes = rx_Readv(acall, rxiov, &nio, RX_MAXIOVECS, length);
423 COND_RE_GLOCK(locked);
425 afs_warn("afs_NoCacheFetchProc: rx_Read error. Return code was %d\n", bytes);
427 unlock_and_release_pages(auio);
429 } else if (bytes == 0) {
430 /* we failed to read the full length */
432 afs_warn("afs_NoCacheFetchProc: rx_Read returned zero. Aborting.\n");
433 unlock_and_release_pages(auio);
437 auio->uio_resid -= bytes;
440 pp = (bypass_page_t)auio->uio_iov[curpage].iov_base;
441 if (pageoff + (rxiov[iovno].iov_len - iovoff) <= auio->uio_iov[curpage].iov_len) {
442 /* Copy entire (or rest of) current iovec into current page */
444 afs_bypass_copy_page(pp, pageoff, rxiov, iovno, iovoff, auio, curpage, 0);
445 length -= (rxiov[iovno].iov_len - iovoff);
446 pageoff += rxiov[iovno].iov_len - iovoff;
450 /* Copy only what's needed to fill current page */
452 afs_bypass_copy_page(pp, pageoff, rxiov, iovno, iovoff, auio, curpage, 1);
453 length -= (auio->uio_iov[curpage].iov_len - pageoff);
454 iovoff += auio->uio_iov[curpage].iov_len - pageoff;
455 pageoff = auio->uio_iov[curpage].iov_len;
458 /* we filled a page, or this is the last page. conditionally release it */
459 if (pp && ((pageoff == auio->uio_iov[curpage].iov_len &&
460 release_pages) || (length == 0 && iovno >= nio)))
461 release_full_page(pp, pageoff);
463 if (length == 0 && iovno >= nio)
470 osi_FreeSmallSpace(rxiov);
475 /* dispatch a no-cache read request */
477 afs_ReadNoCache(struct vcache *avc,
478 struct nocache_read_request *bparms,
483 struct brequest *breq;
484 struct vrequest *areq;
486 /* the reciever will free this */
487 areq = osi_Alloc(sizeof(struct vrequest));
491 afs_warn("afs_ReadNoCache VCache Error!\n");
494 if ((code = afs_InitReq(areq, acred))) {
495 afs_warn("afs_ReadNoCache afs_InitReq error!\n");
500 code = afs_VerifyVCache(avc, areq);
504 code = afs_CheckCode(code, areq, 11); /* failed to get it */
505 afs_warn("afs_ReadNoCache Failed to verify VCache!\n");
511 /* and queue this one */
515 breq = afs_BQueue(BOP_FETCH_NOCACHE, avc, B_DONTWAIT, 0, acred, 1, 1,
516 bparms, (void *)0, (void *)0);
521 afs_osi_Wait(10 * bcnt, 0, 0);
533 /* If there's a problem before we queue the request, we need to
534 * do everything that would normally happen when the request was
535 * processed, like unlocking the pages and freeing memory.
537 unlock_and_release_pages(bparms->auio);
538 osi_Free(areq, sizeof(struct vrequest));
539 osi_Free(bparms->auio->uio_iov,
540 bparms->auio->uio_iovcnt * sizeof(struct iovec));
541 osi_Free(bparms->auio, sizeof(struct uio));
542 osi_Free(bparms, sizeof(struct nocache_read_request));
547 /* Cannot have static linkage--called from BPrefetch (afs_daemons) */
549 afs_PrefetchNoCache(struct vcache *avc,
551 struct nocache_read_request *bparms)
555 struct iovec *iovecp;
557 struct vrequest *areq;
559 struct rx_connection *rxconn;
560 #ifdef AFS_64BIT_CLIENT
561 afs_int32 length_hi, bytes, locked;
565 struct rx_call *tcall;
567 struct AFSVolSync tsync;
568 struct AFSFetchStatus OutStatus;
569 struct AFSCallBack CallBack;
571 struct tlocal1 *tcallspec;
576 iovecp = auio->uio_iov;
579 tcallspec = osi_Alloc(sizeof(struct tlocal1));
581 tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK /* ignored */, &rxconn);
583 avc->callback = tc->parent->srvr->server;
584 tcall = rx_NewCall(rxconn);
585 #ifdef AFS_64BIT_CLIENT
586 if (!afs_serverHasNo64Bit(tc)) {
587 code = StartRXAFS_FetchData64(tcall,
588 (struct AFSFid *) &avc->f.fid.Fid,
592 COND_GUNLOCK(locked);
593 bytes = rx_Read(tcall, (char *)&length_hi,
595 COND_RE_GLOCK(locked);
597 if (bytes != sizeof(afs_int32)) {
599 code = rx_Error(tcall);
600 COND_GUNLOCK(locked);
601 code = rx_EndCall(tcall, code);
602 COND_RE_GLOCK(locked);
606 } /* afs_serverHasNo64Bit */
607 if (code == RXGEN_OPCODE || afs_serverHasNo64Bit(tc)) {
608 if (auio->uio_offset > 0x7FFFFFFF) {
612 pos = auio->uio_offset;
613 COND_GUNLOCK(locked);
615 tcall = rx_NewCall(rxconn);
616 code = StartRXAFS_FetchData(tcall,
617 (struct AFSFid *) &avc->f.fid.Fid,
618 pos, bparms->length);
619 COND_RE_GLOCK(locked);
621 afs_serverSetNo64Bit(tc);
624 code = StartRXAFS_FetchData(tcall,
625 (struct AFSFid *) &avc->f.fid.Fid,
626 auio->uio_offset, bparms->length);
629 code = afs_NoCacheFetchProc(tcall, avc, auio,
630 1 /* release_pages */,
633 afs_warn("BYPASS: StartRXAFS_FetchData failed: %d\n", code);
634 unlock_and_release_pages(auio);
638 code = EndRXAFS_FetchData(tcall, &tcallspec->OutStatus,
639 &tcallspec->CallBack,
642 afs_warn("BYPASS: NoCacheFetchProc failed: %d\n", code);
644 code = rx_EndCall(tcall, code);
646 afs_warn("BYPASS: No connection.\n");
648 unlock_and_release_pages(auio);
651 } while (afs_Analyze(tc, rxconn, code, &avc->f.fid, areq,
652 AFS_STATS_FS_RPCIDX_FETCHDATA,
656 * Copy appropriate fields into vcache
660 afs_ProcessFS(avc, &tcallspec->OutStatus, areq);
662 osi_Free(areq, sizeof(struct vrequest));
663 osi_Free(tcallspec, sizeof(struct tlocal1));
664 osi_Free(bparms, sizeof(struct nocache_read_request));
666 /* in UKERNEL, the "pages" are passed in */
667 osi_Free(iovecp, auio->uio_iovcnt * sizeof(struct iovec));
668 osi_Free(auio, sizeof(struct uio));