Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 142 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/posix/posix_fallocate64.c b/REORG.TODO/sysdeps/posix/posix_fallocate64.c
new file mode 100644
index 0000000000..a637ebe0c6
--- /dev/null
+++ b/REORG.TODO/sysdeps/posix/posix_fallocate64.c
@@ -0,0 +1,142 @@
+/* Copyright (C) 2000-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <sys/fcntl.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+
+/* Reserve storage for the data of the file associated with FD.  This
+   emulation is far from perfect, but the kernel cannot do not much
+   better for network file systems, either.  */
+
+int
+__posix_fallocate64_l64 (int fd, __off64_t offset, __off64_t len)
+{
+  struct stat64 st;
+
+  if (offset < 0 || len < 0)
+    return EINVAL;
+
+  /* Perform overflow check.  The outer cast relies on a GCC
+     extension.  */
+  if ((__off64_t) ((uint64_t) offset + (uint64_t) len) < 0)
+    return EFBIG;
+
+  /* pwrite64 below will not do the right thing in O_APPEND mode.  */
+  {
+    int flags = __fcntl (fd, F_GETFL, 0);
+    if (flags < 0 || (flags & O_APPEND) != 0)
+      return EBADF;
+  }
+
+  /* We have to make sure that this is really a regular file.  */
+  if (__fxstat64 (_STAT_VER, fd, &st) != 0)
+    return EBADF;
+  if (S_ISFIFO (st.st_mode))
+    return ESPIPE;
+  if (! S_ISREG (st.st_mode))
+    return ENODEV;
+
+  if (len == 0)
+    {
+      /* This is racy, but there is no good way to satisfy a
+	 zero-length allocation request.  */
+      if (st.st_size < offset)
+	{
+	  int ret = __ftruncate64 (fd, offset);
+
+	  if (ret != 0)
+	    ret = errno;
+	  return ret;
+	}
+      return 0;
+    }
+
+  /* Minimize data transfer for network file systems, by issuing
+     single-byte write requests spaced by the file system block size.
+     (Most local file systems have fallocate support, so this fallback
+     code is not used there.)  */
+
+  unsigned increment;
+  {
+    struct statfs64 f;
+
+    if (__fstatfs64 (fd, &f) != 0)
+      return errno;
+    if (f.f_bsize == 0)
+      increment = 512;
+    else if (f.f_bsize < 4096)
+      increment = f.f_bsize;
+    else
+      /* NFS clients do not propagate the block size of the underlying
+	 storage and may report a much larger value which would still
+	 leave holes after the loop below, so we cap the increment at
+	 4096.  */
+      increment = 4096;
+  }
+
+  /* Write a null byte to every block.  This is racy; we currently
+     lack a better option.  Compare-and-swap against a file mapping
+     might address local races, but requires interposition of a signal
+     handler to catch SIGBUS.  */
+  for (offset += (len - 1) % increment; len > 0; offset += increment)
+    {
+      len -= increment;
+
+      if (offset < st.st_size)
+	{
+	  unsigned char c;
+	  ssize_t rsize = __libc_pread64 (fd, &c, 1, offset);
+
+	  if (rsize < 0)
+	    return errno;
+	  /* If there is a non-zero byte, the block must have been
+	     allocated already.  */
+	  else if (rsize == 1 && c != 0)
+	    continue;
+	}
+
+      if (__libc_pwrite64 (fd, "", 1, offset) != 1)
+	return errno;
+    }
+
+  return 0;
+}
+
+#undef __posix_fallocate64_l64
+#include <shlib-compat.h>
+#include <bits/wordsize.h>
+
+#if __WORDSIZE == 32 && SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3)
+
+int
+attribute_compat_text_section
+__posix_fallocate64_l32 (int fd, off64_t offset, size_t len)
+{
+  return __posix_fallocate64_l64 (fd, offset, len);
+}
+
+versioned_symbol (libc, __posix_fallocate64_l64, posix_fallocate64,
+		  GLIBC_2_3_3);
+compat_symbol (libc, __posix_fallocate64_l32, posix_fallocate64, GLIBC_2_2);
+#else
+strong_alias (__posix_fallocate64_l64, posix_fallocate64);
+#endif