shithub: gefs

Info  •  Files  •  Log  •  Branches

snap: correct snap refcounting, relink open mounts

--- a/snap.c

+++ b/snap.c

@@ -271,10 +271,12 @@

 delsnap(Tree *t, vlong succ, char *name)

 {

 	char buf[4][Kvmax], *e;

+	int nm, deltree;

+	Mount *mnt;

 	Msg m[4];

-	int nm;

 	nm = 0;

+	deltree = 0;

 	if(name != nil){

 		if(strcmp(name, "dump") == 0

 		|| strcmp(name, "empty") == 0

@@ -293,6 +295,7 @@

 	}

 	if(t->nlbl == 0 && t->nref <= 1){

+		deltree = 1;

 		m[nm].op = Orelink;

 		retag2kv(t->pred, succ, 0, 0, &m[nm], buf[nm], sizeof(buf[nm]));

 		nm++;

@@ -309,10 +312,6 @@

 		m[nm].v = nil;

 		m[nm].nv = 0;

 		nm++;

-	}else{

-		m[nm].op = Oinsert;

-		tree2kv(t, &m[nm], buf[nm], sizeof(buf[nm]));

-		nm++;

 	}

 	assert(nm <= nelem(m));

 	if((e = flushdlcache(1)) != nil)

@@ -321,6 +320,14 @@

 		return e;

 	if((e = reclaimblocks(t->gen, succ, t->pred)) != nil)

 		return e;

+	if(deltree){

+		for(mnt = fs->mounts; mnt != nil; mnt = mnt->next){

+			if(mnt->root->gen == t->succ)

+				mnt->root->pred = t->pred;

+			if(mnt->root->gen == t->pred)

+				mnt->root->succ = t->succ;

+		}

+	}

 	return nil;

 }

@@ -417,10 +424,6 @@

 	t->ht = o->ht;

 	t->bp = o->bp;

 	t->succ = -1;

-	if(o->nlbl == 0 && o->nref == 1)

-		t->pred = o->pred;

-	else

-		t->pred = o->gen;

 	t->base = o->base;

 	t->gen = o->memgen;

 	t->memgen = aincv(&fs->nextgen, 1);

@@ -427,8 +430,15 @@

 	i = 0;

 	m[i].op = Orelink;

-	retag2kv(o->gen, t->gen, -1, 1, &m[i], buf[i], sizeof(buf[i]));

+	if(o->nlbl == 0 && o->nref == 1){

+		t->pred = o->pred;

+		retag2kv(t->pred, t->gen, 0, 0, &m[i], buf[i], sizeof(buf[i]));

+	}else{

+		t->pred = o->gen;

+		retag2kv(t->pred, t->gen, -1, 1, &m[i], buf[i], sizeof(buf[i]));

+	}

 	i++;

+

 	m[i].op = Oinsert;

 	tree2kv(t, &m[i], buf[i], sizeof(buf[i]));

 	i++;