venti: fix sync deadlock, add /proc stub

1 files changed, 59 insertions, 151 deletions

diff --git a/src/cmd/venti/srv/syncindex0.c b/src/cmd/venti/srv/syncindex0.c
index 98f6adf1..be3a2ea0 100644
--- a/src/cmd/venti/srv/syncindex0.c
+++ b/src/cmd/venti/srv/syncindex0.c
@@ -2,184 +2,92 @@
 #include "dat.h"
 #include "fns.h"
 
-enum
+static int
+syncarenaindex(Arena *arena, u64int a0)
 {
-	ClumpChunks	= 32*1024
-};
-
-static int missing, wrong;
-
-/*
- * shell sort is plenty good enough
- * because we're going to do a bunch of disk i/o's
- */
-static void
-sortclumpinfo(ClumpInfo *ci, int *s, int n)
-{
-	int i, j, m, t;
-
-	for(m = (n + 3) / 5; m > 0; m = (m + 1) / 3){
-		for(i = n - m; i-- > 0;){
-			for(j = i + m; j < n; j += m){
-				if(memcmp(ci[s[j - m]].score, ci[s[j]].score, VtScoreSize) <= 0)
-					break;
-				t = s[j];
-				s[j] = s[j - m];
-				s[j - m] = t;
-			}
-		}
-	}
-}
-
-int
-syncarenaindex(Index *ix, Arena *arena, u32int clump, u64int a, int fix, int *pflush, int check)
-{
-	Packet *pack;
-	IEntry ie;
+	int ok;
+	u32int clump;
+	u64int a;
+	ClumpInfo ci;
 	IAddr ia;
-	ClumpInfo *ci, *cis;
-	u64int *addrs;
-	int i, n, ok, *s, flush;
-
-	trace(TraceProc, "syncarenaindex enter");
+	AState as;
+	
+	if(arena->diskstats.clumps == arena->memstats.clumps)
+		return 0;
+	
+	memset(&as, 0, sizeof as);
+	as.arena = arena;
+	as.stats = arena->diskstats;
 
-	flush = 0;
-	cis = MKN(ClumpInfo, ClumpChunks);
-	addrs = MKN(u64int, ClumpChunks);
-	s = MKN(int, ClumpChunks);
 	ok = 0;
-	for(; clump < arena->memstats.clumps; clump += n){
-		n = ClumpChunks;
-		if(n > arena->memstats.clumps - clump)
-			n = arena->memstats.clumps - clump;
-		n = readclumpinfos(arena, clump, cis, n);
-		if(n <= 0){
-			fprint(2, "arena directory read failed\n");
+	a = a0 + arena->diskstats.used;
+	for(clump=arena->diskstats.clumps; clump < arena->memstats.clumps; clump++){
+		if(readclumpinfo(arena, clump, &ci) < 0){
+			fprint(2, "%s: clump %d: cannot read clumpinfo\n",
+				arena->name, clump);
 			ok = -1;
 			break;
 		}
 
-		for(i = 0; i < n; i++){
-			addrs[i] = a;
-			a += cis[i].size + ClumpSize;
-			s[i] = i;
-		}
-
-		sortclumpinfo(cis, s, n);
+		ia.type = ci.type;
+		ia.size = ci.uncsize;
+		ia.addr = a;
+		ia.blocks = (ClumpSize + ci.size + (1 << ABlockLog) - 1) >> ABlockLog;
+		a += ClumpSize + ci.size;
 
-		for(i = 0; i < n; i++){
-			ci = &cis[s[i]];
-			ia.type = ci->type;
-			ia.size = ci->uncsize;
-			ia.addr = addrs[s[i]];
-			ia.blocks = (ci->size + ClumpSize + (1 << ABlockLog) - 1) >> ABlockLog;
-
-			if(!check)
-				goto Add;
-			if(loadientry(ix, ci->score, ci->type, &ie) < 0){
-				trace(TraceProc, "syncarenaindex missing block %V.%d", ci->score, ci->type);
-				missing++;
-			if(0)	fprint(2, "missing block type=%d score=%V\n", ci->type, ci->score);
-			}else if(iaddrcmp(&ia, &ie.ia) != 0){
-				trace(TraceProc, "syncarenaindex mismatched entry");
-				fprint(2, "\nmismatched index entry and clump at %d\n", clump + i);
-				fprint(2, "\tclump: type=%d size=%d blocks=%d addr=%lld\n", ia.type, ia.size, ia.blocks, ia.addr);
-				fprint(2, "\tindex: type=%d size=%d block=%d addr=%lld\n", ie.ia.type, ie.ia.size, ie.ia.blocks, ie.ia.addr);
-				pack = readlump(ie.score, ie.ia.type, ie.ia.size, nil);
-				packetfree(pack);
-				if(pack != nil){
-					fprint(2, "duplicated lump\n");
-					continue;
-				}
-				wrong++;
-			}else
-				continue;
-		Add:
-			if(!fix){
-				ok = -1;
-				continue;
-			}
-			flush = 1;
-			trace(TraceProc, "syncarenaindex insert %V", ci->score);
-			insertscore(ci->score, &ia, IEDirty);
-		}
-
-		if(0 && clump / 1000 != (clump + n) / 1000)
-			fprint(2, ".");
-	}
-	free(cis);
-	free(addrs);
-	free(s);
-	if(flush){
-		flushdcache();
-		*pflush = 1;
+		as.stats.used += ClumpSize + ci.size;
+		as.stats.uncsize += ia.size;
+		as.stats.clumps++;
+		if(ci.uncsize > ci.size)
+			as.stats.cclumps++;
+		as.aa = a;
+		insertscore(ci.score, &ia, IEDirty, &as);
 	}
+	flushdcache();
 	return ok;
 }
 
 int
-syncindex(Index *ix, int fix, int mustflush, int check)
+syncindex(Index *ix)
 {
 	Arena *arena;
-	AState as;
-	u64int a;
-	int i, e, e1, ok, ok1, flush;
+	int i, e, e1, ok;
 
 	ok = 0;
-	flush = 0;
 	for(i = 0; i < ix->narenas; i++){
 		trace(TraceProc, "syncindex start %d", i);
 		arena = ix->arenas[i];
-		/*
-		 * Syncarena will scan through the arena looking for blocks
-		 * that have been forgotten.  It will update arena->memstats.used,
-		 * so save the currenct copy as the place to start the 
-		 * syncarenaindex scan.
-		 */
-		a = arena->memstats.used;
-		e = syncarena(arena, ix->amap[i].start, TWID32, fix, fix);
+		e = syncarena(arena, TWID32, 1, 1);
 		e1 = e;
-		if(fix)
-			e1 &= ~(SyncHeader|SyncCIZero|SyncCIErr);
-		if(e1 == SyncHeader)
+		e1 &= ~(SyncHeader|SyncCIZero|SyncCIErr);
+		if(e & SyncHeader)
 			fprint(2, "arena %s: header is out-of-date\n", arena->name);
-		if(e1)
+		if(e1){
+			fprint(2, "arena %s: %x\n", arena->name, e1);
 			ok = -1;
-		else{
-			/*
-			 * use diskstats not memstats here, because diskstats
-			 * is what has been indexed; memstats is what has 
-			 * made it to disk (confusing names).
-			 */
-			ok1 = syncarenaindex(ix, arena,
-					arena->diskstats.clumps,
-					ix->amap[i].start + arena->diskstats.used,
-					fix, &flush, check);
-			if(ok1 < 0)
-				fprint(2, "syncarenaindex: %r\n");
-			if(fix && ok1==0 && (e & SyncHeader) && wbarena(arena) < 0)
-				fprint(2, "arena=%s header write failed: %r\n", arena->name);
-			ok |= ok1;
+			continue;
+		}
+		flushdcache();
+		
+		if(arena->memstats.clumps == arena->diskstats.clumps)
+			continue;
+		
+		fprint(2, "%T %s: indexing %d clumps...\n",
+			arena->name,
+			arena->memstats.clumps - arena->diskstats.clumps);
 
-			as.arena = arena;
-			as.aa = ix->amap[i].start + arena->memstats.used;
-			as.stats = arena->memstats;
-			setdcachestate(&as);
+		if(syncarenaindex(arena, ix->amap[i].start) < 0){
+			fprint(2, "arena %s: syncarenaindex: %r\n", arena->name);
+			ok = -1;
+			continue;
+		}
+		if(wbarena(arena) < 0){
+			fprint(2, "arena %s: wbarena: %r\n", arena->name);
+			ok = -1;
+			continue;
 		}
-	}
-	if(missing || wrong)
-		fprint(2, "syncindex: %d missing entries, %d wrong entries (flush=%d)\n", missing, wrong, flush);
-	if(fix && wbindex(ix) < 0){
-		fprint(2, "can't write back index header for %s: %r\n", ix->name);
-		return -1;
-	}
-	if(fix && flush){
 		flushdcache();
-		if(mustflush){
-			flushicache();
-			flushdcache();
-		}else
-			kickicache();
+		delaykickicache();
 	}
 	return ok;
 }