The DT_* values returned by getdents (readdir) are only hints and
not required. In fact, some Linux filesystems return DT_UNKNOWN
for most entries, regardless of actual type. This causes make
to mis-match patterns with a trailing slash (via GLOB_ONLYDIR)
(see make's functions/wildcard test case). Thus, this patch
detects that case and uses is_dir() to make the type known enough
for proper operation.
Performance in non-DT_UNKNOWN cases is not affected.
The lack of DT_* is a well known issue on older XFS installations
(for example, RHEL 7 and 8, Fedora 28) but can be recreated by
creating an XFS filesystem with flags that mimic older behavior:
$ fallocate -l 10G /xfs.fs
$ mkfs.xfs -n ftype=0 -m crc=0 -f /xfs.fs
$ mkdir /xfs
$ mount -o loop /xfs.fs /xfs
[tested by importing this change to glibc, and using that to run make's
testsuite]
diff --git a/lib/glob.c b/lib/glob.c
index 22c459574..d0521bb4a 100644
--- a/lib/glob.c
+++ b/lib/glob.c
@@ -1381,7 +1381,26 @@ glob_in_dir (const char *pattern, const char *directory,
int flags,
if (flags & GLOB_ONLYDIR)
switch (readdir_result_type (d))
{
- case DT_DIR: case DT_LNK: case DT_UNKNOWN: break;
+ case DT_DIR: case DT_LNK: break;
+ case DT_UNKNOWN:
+ {
+ /* The filesystem was too lazy to give us a hint,
+ so we have to do it the hard way. */
+ char *fullpath, *p;
+ bool isdir;
+ fullpath = malloc (strlen (directory) + strlen (d.name) +
2);
+ if (fullpath == NULL)
+ /* This matches old behavior wrt DT_UNKNOWN. */
+ break;
+ p = stpcpy (fullpath, directory);
+ *p++ = '/';
+ strcpy (p, d.name);
+ isdir = is_dir (fullpath);
+ free (fullpath);
+ if (isdir)
+ break;
+ continue;
+ }
default: continue;
}
