Cleanup XXXdir functions to eliminate global hash table of

telldir positions.  This will allow (future) locking on a
per-DIR basis (for MT-safety).  For now, this change does
the following:

  o Remove the hash table from telldir.c.  Recode to use queue
    macros.

  o Remove 'const' from 'telldir(const DIR *)'.

  o Remove 'register' variables as suggested in a recent
    thread.

No response from: -current

lib/libc/gen/closedir.c

@@ -42,14 +42,14 @@ static char sccsid[] = "@(#)closedir.c	8.1 (Berkeley) 6/10/93";
 #include <stdlib.h>
 #include <unistd.h>
 
-extern void _reclaim_telldir __P(( const DIR * ));
+extern void _reclaim_telldir __P((DIR *));
 
 /*
  * close a directory.
  */
 int
 closedir(dirp)
-	register DIR *dirp;
+	DIR *dirp;
 {
 	int fd;
 
@@ -58,7 +58,7 @@ closedir(dirp)
 	dirp->dd_fd = -1;
 	dirp->dd_loc = 0;
 	free((void *)dirp->dd_buf);
-	free((void *)dirp);
 	_reclaim_telldir(dirp);
+	free((void *)dirp);
 	return(_close(fd));
 }

lib/libc/gen/directory.3

@@ -57,7 +57,7 @@
 .Ft int
 .Fn readdir_r "DIR *dirp" "struct dirent *entry" "struct dirent **result"
 .Ft long
-.Fn telldir "const DIR *dirp"
+.Fn telldir "DIR *dirp"
 .Ft void
 .Fn seekdir "DIR *dirp" "long  loc"
 .Ft void

lib/libc/gen/opendir.c

@@ -259,6 +259,8 @@ __opendir2(name, flags)
 	dirp->dd_loc = 0;
 	dirp->dd_fd = fd;
 	dirp->dd_flags = flags;
+	dirp->dd_loccnt = 0;
+	LIST_INIT(&dirp->dd_locq);
 
 	/*
 	 * Set up seek point for rewinddir.

lib/libc/gen/readdir.c

@@ -52,9 +52,9 @@ static char sccsid[] = "@(#)readdir.c	8.3 (Berkeley) 9/29/94";
  */
 struct dirent *
 readdir(dirp)
-	register DIR *dirp;
+	DIR *dirp;
 {
-	register struct dirent *dp;
+	struct dirent *dp;
 
 	for (;;) {
 		if (dirp->dd_loc >= dirp->dd_size) {
@@ -90,9 +90,10 @@ readdir_r(dirp, entry, result)
 	struct dirent **result;
 {
 	struct dirent *dp;
-	int ret, saved_errno;
-
+	int saved_errno;
 #ifdef _THREAD_SAFE
+	int ret;
+
 	if ((ret = _FD_LOCK(dirp->dd_fd, FD_READ, NULL)) != 0)
 		return (ret);
 #endif

lib/libc/gen/telldir.c

@@ -29,6 +29,8 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
+ *
+ * $FreeBSD$
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
@@ -53,40 +55,29 @@ static char sccsid[] = "@(#)telldir.c	8.1 (Berkeley) 6/4/93";
  * cookie returned by getdirentries and the offset within the buffer
  * associated with that return value.
  */
-struct ddloc {
-	struct	ddloc *loc_next;/* next structure in list */
+struct _ddloc {
+	LIST_ENTRY(_ddloc) loc_lqe; /* entry in list */
 	long	loc_index;	/* key associated with structure */
 	long	loc_seek;	/* magic cookie returned by getdirentries */
 	long	loc_loc;	/* offset of entry in buffer */
-	const DIR* loc_dirp;	/* directory which used this entry */
 };
 
-#define	NDIRHASH	32	/* Num of hash lists, must be a power of 2 */
-#define	LOCHASH(i)	((i)&(NDIRHASH-1))
-
-static long	dd_loccnt;	/* Index of entry for sequential readdir's */
-static struct	ddloc *dd_hash[NDIRHASH];   /* Hash list heads for ddlocs */
-
 /*
  * return a pointer into a directory
  */
 long
 telldir(dirp)
-	const DIR *dirp;
+	DIR *dirp;
 {
-	register int index;
-	register struct ddloc *lp;
+	struct _ddloc *lp;
 
-	if ((lp = (struct ddloc *)malloc(sizeof(struct ddloc))) == NULL)
+	if ((lp = (struct _ddloc *)malloc(sizeof(struct _ddloc))) == NULL)
 		return (-1);
-	index = dd_loccnt++;
-	lp->loc_index = index;
+	lp->loc_index = dirp->dd_loccnt++;
 	lp->loc_seek = dirp->dd_seek;
 	lp->loc_loc = dirp->dd_loc;
-	lp->loc_dirp = dirp;
-	lp->loc_next = dd_hash[LOCHASH(index)];
-	dd_hash[LOCHASH(index)] = lp;
-	return (index);
+	LIST_INSERT_HEAD(&dirp->dd_locq, lp, loc_lqe);
+	return (lp->loc_index);
 }
 
 /*
@@ -95,20 +86,15 @@ telldir(dirp)
  */
 void
 _seekdir(dirp, loc)
-	register DIR *dirp;
+	DIR *dirp;
 	long loc;
 {
-	register struct ddloc *lp;
-	register struct ddloc **prevlp;
+	struct _ddloc *lp;
 	struct dirent *dp;
 
-	prevlp = &dd_hash[LOCHASH(loc)];
-	lp = *prevlp;
-	while (lp != NULL) {
+	LIST_FOREACH(lp, &dirp->dd_locq, loc_lqe) {
 		if (lp->loc_index == loc)
 			break;
-		prevlp = &lp->loc_next;
-		lp = lp->loc_next;
 	}
 	if (lp == NULL)
 		return;
@@ -124,7 +110,7 @@ _seekdir(dirp, loc)
 	}
 found:
 #ifdef SINGLEUSE
-	*prevlp = lp->loc_next;
+	LIST_REMOVE(lp, loc_lqe);
 	free((caddr_t)lp);
 #endif
 }
@@ -134,24 +120,16 @@ found:
  */
 void
 _reclaim_telldir(dirp)
-	register const DIR *dirp;
+	DIR *dirp;
 {
-	register struct ddloc *lp;
-	register struct ddloc **prevlp;
-	int i;
+	struct _ddloc *lp;
+	struct _ddloc *templp;
 
-	for (i = 0; i < NDIRHASH; i++) {
-		prevlp = &dd_hash[i];
-		lp = *prevlp;
-		while (lp != NULL) {
-			if (lp->loc_dirp == dirp) {
-				*prevlp = lp->loc_next;
-				free((caddr_t)lp);
-				lp = *prevlp;
-				continue;
-			}
-			prevlp = &lp->loc_next;
-			lp = lp->loc_next;
-		}
+	lp = LIST_FIRST(&dirp->dd_locq);
+	while (lp != NULL) {
+		templp = lp;
+		lp = LIST_NEXT(lp, loc_lqe);
+		free(templp);
 	}
+	LIST_INIT(&dirp->dd_locq);
 }