Finally removed the stat() and fstat() calls from the opendir() code.

They were made excessive in r205424 by opening with O_DIRECTORY.
Also eliminated the fcntl() call used to set FD_CLOEXEC by opening
with O_CLOEXEC.

(fdopendir() still checks that the passed descriptor is a directory,
and sets FD_CLOEXEC on it.)

Reviewed by:	ed

1 files changed, 14 insertions, 24 deletions

diff --git a/lib/libc/gen/opendir.c b/lib/libc/gen/opendir.c
index 407c047..3beead7 100644
--- a/lib/libc/gen/opendir.c
+++ b/lib/libc/gen/opendir.c
@@ -66,7 +66,17 @@ opendir(const char *name)
 DIR *
 fdopendir(int fd)
 {
+	struct stat statb;
 
+	/* Check that fd is associated with a directory. */
+	if (_fstat(fd, &statb) != 0)
+		return (NULL);
+	if (!S_ISDIR(statb.st_mode)) {
+		errno = ENOTDIR;
+		return (NULL);
+	}
+	if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
+		return (NULL);
 	return (__opendir_common(fd, NULL, DTF_HIDEW|DTF_NODUP));
 }
 
@@ -74,21 +84,11 @@ DIR *
 __opendir2(const char *name, int flags)
 {
 	int fd;
-	struct stat statb;
 	DIR *dir;
 	int saved_errno;
 
-	/*
-	 * stat() before _open() because opening of special files may be
-	 * harmful.
-	 */
-	if (stat(name, &statb) != 0)
-		return (NULL);
-	if (!S_ISDIR(statb.st_mode)) {
-		errno = ENOTDIR;
-		return (NULL);
-	}
-	if ((fd = _open(name, O_RDONLY | O_NONBLOCK | O_DIRECTORY)) == -1)
+	if ((fd = _open(name,
+	    O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_CLOEXEC)) == -1)
 		return (NULL);
 
 	dir = __opendir_common(fd, name, flags);
@@ -119,19 +119,9 @@ __opendir_common(int fd, const char *name, int flags)
 	int saved_errno;
 	int unionstack;
 	int fd2;
-	struct stat statb;
 
-	dirp = NULL;
-	/* _fstat() the open handler because the file may have changed.  */
-	if (_fstat(fd, &statb) != 0)
-		goto fail;
-	if (!S_ISDIR(statb.st_mode)) {
-		errno = ENOTDIR;
-		goto fail;
-	}
-	if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 ||
-	    (dirp = malloc(sizeof(DIR) + sizeof(struct _telldir))) == NULL)
-		goto fail;
+	if ((dirp = malloc(sizeof(DIR) + sizeof(struct _telldir))) == NULL)
+		return (NULL);
 
 	dirp->dd_td = (struct _telldir *)((char *)dirp + sizeof(DIR));
 	LIST_INIT(&dirp->dd_td->td_locq);