core: use readdir(3) with glibc, and associated cleanup

Starting with glibc-2.23 (i.e. what's in Fedora 25), readdir_r(3)
is marked as deprecated. Specifically the function decl in <dirent.h>
has the deprecated attribute, and now warnings are thrown during the
compile on Fedora 25 builds.

The readdir(_r)(3) man page (on Fedora 25 at least) and World+Dog say
that glibc's readdir(3) is, and always has been, MT-SAFE as long as
only one thread is accessing the directory object returned by opendir().
World+Dog also says there is a potential buffer overflow in readdir_r().
World+Dog suggests that it is preferable to simply use readdir(). There's
an implication that eventually readdir_r(3) will be removed from glibc.
POSIX has, apparently deprecated it in the standard, or even removed it
entirely.

Over and above that, our source near the various uses of readdir(_r)(3)
has a few unsafe uses of strcpy()+strcat().

(AFAIK nobody has looked at the readdir(3) implemenation in *BSD to see
if the same is true on those platforms, and we can't be sure of MacOS
even though we know it's based on *BSD.)

Change-Id: I5481f18ba1eebe7ee177895eecc9a80a71b60568
BUG: 1356998
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>
Reviewed-on: http://review.gluster.org/14838
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Kotresh HR <khiremat@redhat.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/libglusterfs/src/common-utils.c b/libglusterfs/src/common-utils.c
index b2d5a279dc8..3529ad7f897 100644
--- a/libglusterfs/src/common-utils.c
+++ b/libglusterfs/src/common-utils.c
@@ -4084,6 +4084,7 @@ recursive_rmdir (const char *delete_path)
         struct stat     st              = {0,};
         DIR            *dir             = NULL;
         struct dirent  *entry           = NULL;
+        struct dirent   scratch[2]      = {{0,},};
         xlator_t       *this            = NULL;
 
         this = THIS;
@@ -4098,7 +4099,7 @@ recursive_rmdir (const char *delete_path)
                 goto out;
         }
 
-        GF_FOR_EACH_ENTRY_IN_DIR (entry, dir);
+        GF_FOR_EACH_ENTRY_IN_DIR (entry, dir, scratch);
         while (entry) {
                 snprintf (path, PATH_MAX, "%s/%s", delete_path, entry->d_name);
                 ret = sys_lstat (path, &st);
@@ -4121,7 +4122,7 @@ recursive_rmdir (const char *delete_path)
                 gf_msg_debug (this->name, 0, "%s %s", ret ?
                               "Failed to remove" : "Removed", entry->d_name);
 
-                GF_FOR_EACH_ENTRY_IN_DIR (entry, dir);
+                GF_FOR_EACH_ENTRY_IN_DIR (entry, dir, scratch);
         }
 
         ret = sys_closedir (dir);