linux: Move posix dir implementations to Linux

This generic implementation already expects a getdents API which
is Linux specific.  It also allows simplify it by assuming
_DIRENT_HAVE_D_RECLEN and _DIRENT_HAVE_D_OFF support.

The readdir are also expanded on each required implementation,
futher fixes and improvements will make parametrize the
implementation more complex.

Checked on x86_64-linux-gnu, i686-linux-gnu, and with a build
for all affected ABIs.

1 files changed, 93 insertions, 2 deletions

diff --git a/sysdeps/unix/sysv/linux/readdir_r.c b/sysdeps/unix/sysv/linux/readdir_r.c
index 30f237dbcc..0069041394 100644
--- a/sysdeps/unix/sysv/linux/readdir_r.c
+++ b/sysdeps/unix/sysv/linux/readdir_r.c
@@ -19,5 +19,96 @@
 #include <dirent.h>
 
 #if !_DIRENT_MATCHES_DIRENT64
-# include <sysdeps/posix/readdir_r.c>
-#endif
+/* Read a directory entry from DIRP.  */
+int
+__readdir_r (DIR *dirp, struct dirent *entry, struct dirent **result)
+{
+  struct dirent *dp;
+  size_t reclen;
+  const int saved_errno = errno;
+  int ret;
+
+  __libc_lock_lock (dirp->lock);
+
+  do
+    {
+      if (dirp->offset >= dirp->size)
+	{
+	  /* We've emptied out our buffer.  Refill it.  */
+
+	  size_t maxread = dirp->allocation;
+	  ssize_t bytes;
+
+	  maxread = dirp->allocation;
+
+	  bytes = __getdents (dirp->fd, dirp->data, maxread);
+	  if (bytes <= 0)
+	    {
+	      /* On some systems getdents fails with ENOENT when the
+		 open directory has been rmdir'd already.  POSIX.1
+		 requires that we treat this condition like normal EOF.  */
+	      if (bytes < 0 && errno == ENOENT)
+		{
+		  bytes = 0;
+		  __set_errno (saved_errno);
+		}
+	      if (bytes < 0)
+		dirp->errcode = errno;
+
+	      dp = NULL;
+	      break;
+	    }
+	  dirp->size = (size_t) bytes;
+
+	  /* Reset the offset into the buffer.  */
+	  dirp->offset = 0;
+	}
+
+      dp = (struct dirent *) &dirp->data[dirp->offset];
+
+      reclen = dp->d_reclen;
+
+      dirp->offset += reclen;
+
+      dirp->filepos = dp->d_off;
+
+      if (reclen > offsetof (struct dirent, d_name) + NAME_MAX + 1)
+	{
+	  /* The record is very long.  It could still fit into the
+	     caller-supplied buffer if we can skip padding at the
+	     end.  */
+	  size_t namelen = _D_EXACT_NAMLEN (dp);
+	  if (namelen <= NAME_MAX)
+	    reclen = offsetof (struct dirent, d_name) + namelen + 1;
+	  else
+	    {
+	      /* The name is too long.  Ignore this file.  */
+	      dirp->errcode = ENAMETOOLONG;
+	      dp->d_ino = 0;
+	      continue;
+	    }
+	}
+
+      /* Skip deleted and ignored files.  */
+    }
+  while (dp->d_ino == 0);
+
+  if (dp != NULL)
+    {
+      *result = memcpy (entry, dp, reclen);
+      entry->d_reclen = reclen;
+      ret = 0;
+    }
+  else
+    {
+      *result = NULL;
+      ret = dirp->errcode;
+    }
+
+  __libc_lock_unlock (dirp->lock);
+
+  return ret;
+}
+
+weak_alias (__readdir_r, readdir_r)
+#endif /* _DIRENT_MATCHES_DIRENT64  */