venti: new icache

1 files changed, 52 insertions, 40 deletions

diff --git a/src/cmd/venti/srv/icachewrite.c b/src/cmd/venti/srv/icachewrite.c
index 49344c9f..0805001c 100644
--- a/src/cmd/venti/srv/icachewrite.c
+++ b/src/cmd/venti/srv/icachewrite.c
@@ -45,6 +45,16 @@ initicachewrite(void)
 	vtproc(delaykickroundproc, &iwrite.round);
 }
 
+static u64int
+ie2diskaddr(Index *ix, ISect *is, IEntry *ie)
+{
+	u64int bucket, addr;
+
+	bucket = hashbits(ie->score, 32)/ix->div;
+	addr = is->blockbase + ((bucket - is->start) << is->blocklog);
+	return addr;
+}
+
 static IEntry*
 nextchunk(Index *ix, ISect *is, IEntry **pie, u64int *paddr, uint *pnbuf)
 {
@@ -55,13 +65,13 @@ nextchunk(Index *ix, ISect *is, IEntry **pie, u64int *paddr, uint *pnbuf)
 
 	bsize = 1<<is->blocklog;
 	iefirst = *pie;
-	addr = is->blockbase + ((u64int)(hashbits(iefirst->score, 32) / ix->div - is->start) << is->blocklog);
+	addr = ie2diskaddr(ix, is, iefirst);
 	nbuf = 0;
-	for(l=&iefirst->nextdirty; (ie=*l)!=nil; l=&(*l)->nextdirty){
-		naddr = is->blockbase + ((u64int)(hashbits(ie->score, 32) / ix->div - is->start) << is->blocklog);
+	for(l = &iefirst->nextdirty; (ie = *l) != nil; l = &(*l)->nextdirty){
+		naddr = ie2diskaddr(ix, is, ie);
 		if(naddr - addr >= Bufsize)
 			break;
-		nbuf = naddr-addr;
+		nbuf = naddr - addr;
 	}
 	nbuf += bsize;
 
@@ -75,7 +85,7 @@ nextchunk(Index *ix, ISect *is, IEntry **pie, u64int *paddr, uint *pnbuf)
 static int
 icachewritesect(Index *ix, ISect *is, u8int *buf)
 {
-	int err, h, bsize, t;
+	int err, i, werr, h, bsize, t;
 	u32int lo, hi;
 	u64int addr, naddr;
 	uint nbuf, off;
@@ -89,29 +99,32 @@ icachewritesect(Index *ix, ISect *is, u8int *buf)
 	else
 		hi = is->stop * ix->div - 1;
 
-	trace(TraceProc, "icachewritesect enter %ud %ud %llud", lo, hi, iwrite.as.aa);
+	trace(TraceProc, "icachewritesect enter %ud %ud %llud",
+		lo, hi, iwrite.as.aa);
 
 	iedirty = icachedirty(lo, hi, iwrite.as.aa);
 	iedirty = iesort(iedirty);
-	bsize = 1<<is->blocklog;
+	bsize = 1 << is->blocklog;
 	err = 0;
 
 	while(iedirty){
 		disksched();
-		while((t=icachesleeptime) == SleepForever){
+		while((t = icachesleeptime) == SleepForever){
 			sleep(1000);
 			disksched();
 		}
 		if(t < minicachesleeptime)
 			t = minicachesleeptime;
-		sleep(t);
+		if(t > 0)
+			sleep(t);
 		trace(TraceProc, "icachewritesect nextchunk");
 		chunk = nextchunk(ix, is, &iedirty, &addr, &nbuf);
 
-		trace(TraceProc, "icachewritesect readpart 0x%llux+0x%ux", addr, nbuf);
+		trace(TraceProc, "icachewritesect readpart 0x%llux+0x%ux",
+			addr, nbuf);
 		if(readpart(is->part, addr, buf, nbuf) < 0){
-			/* XXX more details here */
-			fprint(2, "icachewriteproc readpart: %r\n");
+			fprint(2, "%s: part %s addr 0x%llux: icachewritesect "
+				"readpart: %r\n", argv0, is->part->name, addr);
 			err  = -1;
 			continue;
 		}
@@ -120,31 +133,34 @@ icachewritesect(Index *ix, ISect *is, u8int *buf)
 		addstat(StatIsectRead, 1);
 
 		for(l=&chunk; (ie=*l)!=nil; l=&ie->nextdirty){
-		again:
-			naddr = is->blockbase + ((u64int)(hashbits(ie->score, 32) / ix->div - is->start) << is->blocklog);
+again:
+			naddr = ie2diskaddr(ix, is, ie);
 			off = naddr - addr;
 			if(off+bsize > nbuf){
-				fprint(2, "whoops! addr=0x%llux nbuf=%ud addr+nbuf=0x%llux naddr=0x%llux\n",
-					addr, nbuf, addr+nbuf, naddr);
+				fprint(2, "%s: whoops! addr=0x%llux nbuf=%ud "
+					"addr+nbuf=0x%llux naddr=0x%llux\n",
+					argv0, addr, nbuf, addr+nbuf, naddr);
 				assert(off+bsize <= nbuf);
 			}
 			unpackibucket(&ib, buf+off, is->bucketmagic);
 			if(okibucket(&ib, is) < 0){
-				fprint(2, "bad bucket XXX\n");
+				fprint(2, "%s: bad bucket XXX\n", argv0);
 				goto skipit;
 			}
-			trace(TraceProc, "icachewritesect add %V at 0x%llux", ie->score, naddr);
+			trace(TraceProc, "icachewritesect add %V at 0x%llux",
+				ie->score, naddr);
 			h = bucklook(ie->score, ie->ia.type, ib.data, ib.n);
 			if(h & 1){
 				h ^= 1;
 				packientry(ie, &ib.data[h]);
 			}else if(ib.n < is->buckmax){
-				memmove(&ib.data[h+IEntrySize], &ib.data[h], ib.n*IEntrySize - h);
+				memmove(&ib.data[h + IEntrySize], &ib.data[h],
+					ib.n*IEntrySize - h);
 				ib.n++;
 				packientry(ie, &ib.data[h]);
 			}else{
-				fprint(2, "bucket overflow XXX\n");
-			skipit:
+				fprint(2, "%s: bucket overflow XXX\n", argv0);
+skipit:
 				err = -1;
 				*l = ie->nextdirty;
 				ie = *l;
@@ -154,33 +170,29 @@ icachewritesect(Index *ix, ISect *is, u8int *buf)
 					break;
 			}
 			packibucket(&ib, buf+off, is->bucketmagic);
-			/* XXX
-			 * This is not quite right - it's good that we 
-			 * update the cached block (if any) here, but
-			 * since the block doesn't get written until writepart
-			 * below, we also need to make sure that the cache 
-			 * doesn't load the stale block before we write it to
-			 * disk below.  We could lock the disk cache during
-			 * the writepart, but that's pretty annoying.
-			 * Another possibility would be never to cache
-			 * index partition blocks.  The hit rate on those is
-			 * miniscule anyway.
-			 */
-			if((b = _getdblock(is->part, naddr, ORDWR, 0)) != nil){
-				memmove(b->data, buf+off, bsize);
-				putdblock(b);
-			}
 		}
 
 		diskaccess(1);
 
 		trace(TraceProc, "icachewritesect writepart", addr, nbuf);
-		if(writepart(is->part, addr, buf, nbuf) < 0 || flushpart(is->part) < 0){
-			/* XXX more details here */
-			fprint(2, "icachewriteproc writepart: %r\n");
+		werr = 0;
+		if(writepart(is->part, addr, buf, nbuf) < 0 || flushpart(is->part) < 0)
+			werr = -1;
+
+		for(i=0; i<nbuf; i+=bsize){
+			if((b = _getdblock(is->part, addr+i, ORDWR, 0)) != nil){
+				memmove(b->data, buf+i, bsize);
+				putdblock(b);
+			}
+		}
+
+		if(werr < 0){
+			fprint(2, "%s: part %s addr 0x%llux: icachewritesect "
+				"writepart: %r\n", argv0, is->part->name, addr);
 			err = -1;
 			continue;
 		}
+		
 		addstat(StatIsectWriteBytes, nbuf);
 		addstat(StatIsectWrite, 1);
 		icacheclean(chunk);