hjfs: dentry qid checking, prevent newentry() from allocating already in use slot

always check if the directory entry qid from the loc still
matches the one on disk before doing anything. helps
catching bugs and is basically equivalent to what cwfs does
with its checktag.

make a haveloc() check in newentry() to make sure we dont
allocate a file slot thats still in use, but deleted.
this seems to fix the NPROC>1 build problems.

5 files changed, 136 insertions, 47 deletions

diff --git a/sys/src/cmd/hjfs/buf.c b/sys/src/cmd/hjfs/buf.c
index 23f533520..51fdff162 100644
--- a/sys/src/cmd/hjfs/buf.c
+++ b/sys/src/cmd/hjfs/buf.c
@@ -269,7 +269,8 @@ getbuf(Dev *d, uvlong off, int type, int nodata)
 	if(nodata)
 		b->type = type;
 	if(b->type != type && type != -1){
-		dprint("hjfs: type mismatch, dev %s, block %lld, got %T, want %T, caller %#p\n", d->name, off, b->type, type, getcallerpc(&d));
+		dprint("hjfs: type mismatch, dev %s, block %lld, got %T, want %T, caller %#p\n",
+			d->name, off, b->type, type, getcallerpc(&d));
 		werrstr("phase error -- type mismatch");
 		putbuf(b);
 		return nil;
diff --git a/sys/src/cmd/hjfs/dump.c b/sys/src/cmd/hjfs/dump.c
index ba6dd5fc0..210e57964 100644
--- a/sys/src/cmd/hjfs/dump.c
+++ b/sys/src/cmd/hjfs/dump.c
@@ -143,8 +143,8 @@ again:
 	p = getbuf(fs->d, l->next->blk, TDENTRY, 0);
 	if(p == nil)
 		goto err;
-	d = &p->de[l->next->deind];
-	for(i = 0; i < d->size; i++){
+	d = getdent(l->next, p);
+	if(d != nil) for(i = 0; i < d->size; i++){
 		rc = getblk(fs, l->next, p, i, &r, GBREAD);
 		if(rc <= 0)
 			continue;
diff --git a/sys/src/cmd/hjfs/fns.h b/sys/src/cmd/hjfs/fns.h
index 510392bc6..0a917191e 100644
--- a/sys/src/cmd/hjfs/fns.h
+++ b/sys/src/cmd/hjfs/fns.h
@@ -8,6 +8,7 @@ void	unpack(Buf *, uchar *);
 Dev*	newdev(char *);
 ThrData*	getthrdata(void);
 Fs*	initfs(Dev *, int, int);
+Dentry*	getdent(FLoc *, Buf *);
 int	getfree(Fs *, uvlong *);
 int	putfree(Fs *, uvlong);
 Chan*	chanattach(Fs *, int);
diff --git a/sys/src/cmd/hjfs/fs1.c b/sys/src/cmd/hjfs/fs1.c
index 472e8852d..b059a39ff 100644
--- a/sys/src/cmd/hjfs/fs1.c
+++ b/sys/src/cmd/hjfs/fs1.c
@@ -29,6 +29,35 @@ chref(Fs *fs, uvlong r, int stat)
 	return rc;
 }
 
+static int
+qidcmp(Qid *a, Qid *b)
+{
+	if(a->type != b->type)
+		return 1;
+	if(a->path != b->path)
+		return 1;
+	return 0;
+}
+
+Dentry*
+getdent(FLoc *l, Buf *b)
+{
+	Dentry *d;
+
+	d = &b->de[l->deind];
+	if((d->mode & (DGONE | DALLOC)) == 0){
+		dprint("hjfs: getdent: file gone, callerpc %#p\n", getcallerpc(&l));
+		werrstr("phase error -- getdent");
+		return nil;
+	}
+	if(qidcmp(d, l) != 0){
+		dprint("hjfs: getdent: wrong qid, callerpc %#p\n", getcallerpc(&l));
+		werrstr("phase error -- getdent");
+		return nil;
+	}
+	return d;
+}
+
 int
 getfree(Fs *fs, uvlong *r)
 {
@@ -364,13 +393,13 @@ haveloc(Fs *fs, uvlong blk, int deind, Loc *next)
 
 	qlock(&fs->loctree);
 	l = next->child;
-	do{
+	if(l != nil) do{
 		if(l->blk == blk && l->deind == deind){
 			qunlock(&fs->loctree);
 			return 1;
 		}
 		l = l->cnext;
-	}while(l != next->child);
+	} while(l != next->child);
 	qunlock(&fs->loctree);
 	return 0;
 }
@@ -511,7 +540,11 @@ getblk(Fs *fs, FLoc *L, Buf *bd, uvlong blk, uvlong *r, int mode)
 	Dentry *d;
 
 	b = bd;
-	d = &bd->de[L->deind];
+	d = getdent(L, b);
+	if(d == nil){
+		dprint("hjfs: getblk: dirent gone\n");
+		return -1;
+	}
 	if(blk < NDIRECT){
 		loc = &d->db[blk];
 		goto found;
@@ -696,7 +729,9 @@ trunc(Fs *fs, FLoc *ll, Buf *bd, uvlong size)
 	uvlong l;
 	int i, j;
 
-	d = &bd->de[ll->deind];
+	d = getdent(ll, bd);
+	if(d == nil)
+		return -1;
 	if(size >= d->size)
 		goto done;
 	blk = HOWMANY(size, RBLOCK);
@@ -758,7 +793,9 @@ findentry(Fs *fs, FLoc *l, Buf *b, char *name, FLoc *rl, int dump)
 	uvlong r;
 	Buf *c;
 	
-	d = &b->de[l->deind];
+	d = getdent(l, b);
+	if(d == nil)
+		return -1;
 	for(i = 0; i < d->size; i++){
 		if(getblk(fs, l, b, i, &r, GBREAD) <= 0)
 			continue;
@@ -816,7 +853,10 @@ deltraverse(Fs *fs, Del *p, Buf *b, Del **last)
 		if(b == nil)
 			return -1;
 	}
-	s = b->de[p->deind].size;
+	d = getdent(p, b);
+	if(d == nil)
+		return -1;
+	s = d->size;
 	for(i = 0; i < s; i++){
 		rc = getblk(fs, p, b, i, &r, GBREAD);
 		if(rc <= 0)
@@ -835,6 +875,7 @@ deltraverse(Fs *fs, Del *p, Buf *b, Del **last)
 					dd = emalloc(sizeof(Del));
 					dd->blk = i;
 					dd->deind = j;
+					dd->Qid = d->Qid;
 					dd->prev = *last;
 					(*last)->next = dd;
 					*last = dd;
@@ -854,8 +895,10 @@ delete(Fs *fs, FLoc *l, Buf *b)
 	Dentry *d;
 	Buf *c;
 	Del *first, *last, *p, *q;
-	
-	d = &b->de[l->deind];
+
+	d = getdent(l, b);
+	if(d == nil)
+		return -1;
 	if((d->type & QTDIR) == 0){
 		trunc(fs, l, b, 0);
 		memset(d, 0, sizeof(*d));
@@ -873,9 +916,12 @@ delete(Fs *fs, FLoc *l, Buf *b)
 			c = getbuf(fs->d, p->blk, TDENTRY, 0);
 		if(c == nil)
 			continue;
-		trunc(fs, p, c, 0);
-		memset(&c->de[p->deind], 0, sizeof(Dentry));
-		c->op |= BDELWRI;
+		d = getdent(p, c);
+		if(d != nil){
+			trunc(fs, p, c, 0);
+			memset(d, 0, sizeof(*d));
+			c->op |= BDELWRI;
+		}
 		if(p != first)
 			putbuf(c);
 	}
@@ -885,16 +931,16 @@ delete(Fs *fs, FLoc *l, Buf *b)
 int
 newentry(Fs *fs, Loc *l, Buf *b, char *name, FLoc *res)
 {
-	Dentry *d;
+	Dentry *d, *dd;
 	uvlong i, si, r;
 	int j, sj, rc;
 	Buf *c;
 	FLoc f;
 
 	si = sj = -1;
-	d = &b->de[l->deind];
-	for(i = 0; i <= d->size; i++){
-		if(i == d->size && si != -1)
+	d = getdent(l, b);
+	if(d != nil) for(i = 0; i <= d->size; i++){
+		if(i >= d->size && si != -1)
 			break;
 		rc = getblk(fs, l, b, i, &r, si == -1 ? GBCREATE : GBREAD);
 		if(rc < 0)
@@ -906,32 +952,34 @@ newentry(Fs *fs, Loc *l, Buf *b, char *name, FLoc *res)
 			continue;
 		if(rc == 0){
 			memset(c->de, 0, sizeof(c->de));
-			if(i == d->size){
-				d->size++;
+			if(i >= d->size){
+				d->size = i+1;
 				b->op |= BDELWRI;
 			}
 			c->op |= BDELWRI;
 		}
 		for(j = 0; j < DEPERBLK; j++){
-			if(si == -1 && (c->de[j].mode & DALLOC) == 0){
-				si = i;
-				sj = j;
+			dd = &c->de[j];
+			if((dd->mode & DALLOC) != 0){
+				if(strcmp(dd->name, name) == 0){
+					werrstr(Eexists);
+					putbuf(c);
+					return 0;
+				}
+				continue;
 			}
-			if(si == -1 && (c->de[j].mode & DGONE) != 0 && !haveloc(fs, r, j, l)){
+			if(si != -1 || haveloc(fs, r, j, l))
+				continue;
+			if((dd->mode & DGONE) != 0){
 				memset(&f, 0, sizeof(f));
 				f.blk = r;
 				f.deind = j;
-				if(delete(fs, &f, c) >= 0){
-					si = i;
-					sj = j;
-				}
-			}
-			if((c->de[j].mode & DALLOC) != 0 &&
-			   strcmp(c->de[j].name, name) == 0){
-				werrstr(Eexists);
-				putbuf(c);
-				return 0;
+				f.Qid = dd->Qid;
+				if(delete(fs, &f, c) < 0)
+					continue;
 			}
+			si = i;
+			sj = j;
 		}
 		putbuf(c);
 	}
@@ -942,5 +990,6 @@ newentry(Fs *fs, Loc *l, Buf *b, char *name, FLoc *res)
 	if(getblk(fs, l, b, si, &res->blk, GBWRITE) <= 0)
 		return -1;
 	res->deind = sj;
+	res->Qid = (Qid){0, 0, 0};
 	return 1;
 }
diff --git a/sys/src/cmd/hjfs/fs2.c b/sys/src/cmd/hjfs/fs2.c
index cdc7a6cd6..d2a4a8830 100644
--- a/sys/src/cmd/hjfs/fs2.c
+++ b/sys/src/cmd/hjfs/fs2.c
@@ -53,7 +53,9 @@ chanwalk(Chan *ch, char *name)
 		chend(ch);
 		return -1;
 	}
-	d = &b->de[ch->loc->deind];
+	d = getdent(ch->loc, b);
+	if(d == nil)
+		goto error;
 	if((d->type & QTDIR) == 0){
 		werrstr(Enotadir);
 		goto error;
@@ -132,7 +134,9 @@ chancreat(Chan *ch, char *name, int perm, int mode)
 		chend(ch);
 		return -1;
 	}
-	d = &b->de[ch->loc->deind];
+	d = getdent(ch->loc, b);
+	if(d == nil)
+		goto error;
 	if((d->type & QTDIR) == 0){
 		werrstr(Enotadir);
 		goto error;
@@ -146,9 +150,9 @@ chancreat(Chan *ch, char *name, int perm, int mode)
 	c = getbuf(ch->fs->d, f.blk, TDENTRY, 0);
 	if(c == nil)
 		goto error;
-	c->op |= BDELWRI;
-	b->op |= BDELWRI;
 	modified(ch, d);
+	b->op |= BDELWRI;
+	c->op |= BDELWRI;
 	if(isdir)
 		perm &= ~0777 | d->mode & 0777;
 	else
@@ -213,7 +217,9 @@ chanopen(Chan *ch, int mode)
 		chend(ch);
 		return -1;
 	}
-	d = &b->de[ch->loc->deind];
+	d = getdent(ch->loc, b);
+	if(d == nil)
+		goto err;
 	if(!permcheck(ch->fs, d, ch->uid, mode & OEXEC)){
 	permerr:
 		werrstr(Eperm);
@@ -325,7 +331,12 @@ chanwrite(Chan *ch, void *buf, ulong n, uvlong off)
 		chend(ch);
 		return -1;
 	}
-	d = &b->de[ch->loc->deind];
+	d = getdent(ch->loc, b);
+	if(d == nil){
+		putbuf(b);
+		chend(ch);
+		return -1;
+	}
 	if((d->type & QTAPPEND) != 0)
 		off = d->size;
 	e = off + n;
@@ -392,7 +403,12 @@ chanread(Chan *ch, void *buf, ulong n, uvlong off)
 		chend(ch);
 		return -1;
 	}
-	d = &b->de[ch->loc->deind];
+	d = getdent(ch->loc, b);
+	if(d == nil){
+		putbuf(b);
+		chend(ch);
+		return -1;
+	}
 	if(off >= d->size)
 		n = 0;
 	else if(off + n > d->size)
@@ -465,6 +481,7 @@ int
 chanstat(Chan *ch, Dir *di)
 {
 	Buf *b;
+	Dentry *d;
 	
 	chbegin(ch);
 	b = getbuf(ch->fs->d, ch->loc->blk, TDENTRY, 0);
@@ -472,7 +489,13 @@ chanstat(Chan *ch, Dir *di)
 		chend(ch);
 		return -1;
 	}
-	statbuf(ch->fs, &b->de[ch->loc->deind], di, nil);
+	d = getdent(ch->loc, b);
+	if(d == nil){
+		putbuf(b);
+		chend(ch);
+		return -1;
+	}
+	statbuf(ch->fs, d, di, nil);
 	putbuf(b);
 	chend(ch);
 	return 0;
@@ -504,7 +527,12 @@ chandirread(Chan *ch, void *buf, ulong n, uvlong off)
 		chend(ch);
 		return -1;
 	}
-	d = &b->de[ch->loc->deind];
+	d = getdent(ch->loc, b);
+	if(d == nil){
+		putbuf(b);
+		chend(ch);
+		return -1;
+	}
 	if(ch->dwblk >= d->size){
 		putbuf(b);
 		chend(ch);
@@ -590,11 +618,16 @@ chanclunk(Chan *ch)
 		b = getbuf(ch->fs->d, ch->loc->blk, TDENTRY, 0);
 		if(b == nil)
 			goto err;
-		if(!permcheck(ch->fs, &p->de[ch->loc->next->deind], ch->uid, OWRITE)){
+		d = getdent(ch->loc->next, p);
+		if(d == nil)
+			goto err;
+		if(!permcheck(ch->fs, d, ch->uid, OWRITE)){
 			werrstr(Eperm);
 			goto err;
 		}
-		d = &b->de[ch->loc->deind];
+		d = getdent(ch->loc, b);
+		if(d == nil)
+			goto err;
 		if((d->type & QTDIR) != 0 && findentry(ch->fs, ch->loc, b, nil, nil, ch->flags & CHFDUMP) != 0)
 			goto inval;
 		if((d->mode & DGONE) != 0)
@@ -653,7 +686,10 @@ chanwstat(Chan *ch, Dir *di)
 		pb = getbuf(ch->fs->d, ch->loc->next->blk, TDENTRY, 0);
 		if(pb == nil)
 			goto error;
-		if(!permcheck(ch->fs, &pb->de[ch->loc->next->deind], ch->uid, OWRITE))
+		d = getdent(ch->loc->next, pb);
+		if(d == nil)
+			goto error;
+		if(!permcheck(ch->fs, d, ch->uid, OWRITE))
 			goto perm;
 		rc = findentry(ch->fs, ch->loc->next, pb, di->name, nil, ch->flags & CHFDUMP);
 		if(rc > 0)
@@ -664,7 +700,9 @@ chanwstat(Chan *ch, Dir *di)
 	b = getbuf(ch->fs->d, ch->loc->blk, TDENTRY, 0);
 	if(b == nil)
 		goto error;
-	d = &b->de[ch->loc->deind];
+	d = getdent(ch->loc, b);
+	if(d == nil)
+		goto error;
 	isdir = (d->type & QTDIR) != 0;
 	owner = ch->uid == d->uid || ingroup(ch->fs, ch->uid, d->gid, 1) || (ch->fs->flags & FSNOPERM) != 0;
 	if((uvlong)~di->length){