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, 3 deletions

diff --git a/libglusterfs/src/common-utils.h b/libglusterfs/src/common-utils.h
index d7277e6e834..aacf2c5a32c 100644
--- a/libglusterfs/src/common-utils.h
+++ b/libglusterfs/src/common-utils.h
@@ -396,15 +396,15 @@ union gf_sock_union {
 
 #define IOV_MIN(n) min(IOV_MAX,n)
 
-#define GF_FOR_EACH_ENTRY_IN_DIR(entry, dir) \
+#define GF_FOR_EACH_ENTRY_IN_DIR(entry, dir, scr) \
         do {\
                 entry = NULL;\
                 if (dir) { \
-                        entry = sys_readdir (dir); \
+                        entry = sys_readdir (dir, scr); \
                         while (entry && (!strcmp (entry->d_name, ".") || \
                             !fnmatch ("*.tmp", entry->d_name, 0) || \
                             !strcmp (entry->d_name, ".."))) { \
-                                entry = sys_readdir (dir); \
+                                entry = sys_readdir (dir, scr); \
                         } \
                 } \
         } while (0)