diff --git a/libc/sysdeps/linux/common/posix_fallocate.c b/libc/sysdeps/linux/common/posix_fallocate.c
index 76771e3..cc4553c 100644
--- a/libc/sysdeps/linux/common/posix_fallocate.c
+++ b/libc/sysdeps/linux/common/posix_fallocate.c
@@ -12,12 +12,88 @@
 #include <fcntl.h>
 #include <bits/kernel-features.h>
 #include <stdint.h>
+#include <sys/statfs.h>
 
 #if defined __NR_fallocate
+/* Reserve storage for the data of the file associated with FD.  */
+/* Adapted from glibc */
+int
+internal_fallocate (int fd, __off_t offset, __off_t len)
+{
+  struct stat64 st;
+  struct statfs f;
+
+  /* `off_t' is a signed type.  Therefore we can determine whether
+     OFFSET + LEN is too large if it is a negative value.  */
+  if (offset < 0 || len < 0)
+    return EINVAL;
+  if (offset + len < 0)
+    return EFBIG;
+
+  /* First thing we have to make sure is that this is really a regular
+     file.  */
+  if (fstat64 (fd, &st) != 0)
+    return EBADF;
+  if (S_ISFIFO (st.st_mode))
+    return ESPIPE;
+  if (! S_ISREG (st.st_mode))
+    return ENODEV;
+
+  if (len == 0)
+    {
+      if (st.st_size < offset)
+	{
+	  int ret = ftruncate (fd, offset);
+
+	  if (ret != 0)
+	    ret = errno;
+	  return ret;
+	}
+      return 0;
+    }
+
+  /* We have to know the block size of the filesystem to get at least some
+     sort of performance.  */
+  if (__libc_fstatfs (fd, &f) != 0)
+    return errno;
+
+  /* Try to play safe.  */
+  if (f.f_bsize == 0)
+    f.f_bsize = 512;
+
+  /* Write something to every block.  */
+  for (offset += (len - 1) % f.f_bsize; len > 0; offset += f.f_bsize)
+    {
+      len -= f.f_bsize;
+
+      if (offset < st.st_size)
+	{
+	  unsigned char c;
+	  ssize_t rsize = __libc_pread (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_pwrite (fd, "", 1, offset) != 1)
+	return errno;
+    }
+
+  return 0;
+}
+
 extern __typeof(fallocate) __libc_fallocate attribute_hidden;
 int posix_fallocate(int fd, __off_t offset, __off_t len)
 {
-	return __libc_fallocate(fd, 0, offset, len);
+	int result = __libc_fallocate(fd, 0, offset, len);
+	if (result != EOPNOTSUPP)
+		return result;
+
+	return internal_fallocate(fd, offset, len);
 }
 # if defined __UCLIBC_HAS_LFS__ && __WORDSIZE == 64
 strong_alias(posix_fallocate,posix_fallocate64)
diff --git a/libc/sysdeps/linux/common/posix_fallocate64.c b/libc/sysdeps/linux/common/posix_fallocate64.c
index 12ddbc2..2f02626 100644
--- a/libc/sysdeps/linux/common/posix_fallocate64.c
+++ b/libc/sysdeps/linux/common/posix_fallocate64.c
@@ -12,15 +12,91 @@
 #include <fcntl.h>
 #include <bits/kernel-features.h>
 #include <stdint.h>
+#include <sys/statfs.h>
 
 #if defined __NR_fallocate
 # if __WORDSIZE == 64
 /* Can use normal posix_fallocate() */
 # elif __WORDSIZE == 32
+/* Reserve storage for the data of the file associated with FD.  */
+/* Adapted from glibc */
+static int
+internal_fallocate64 (int fd, __off64_t offset, __off64_t len)
+{
+  struct stat64 st;
+  struct statfs64 f;
+
+  /* `off64_t' is a signed type.  Therefore we can determine whether
+     OFFSET + LEN is too large if it is a negative value.  */
+  if (offset < 0 || len < 0)
+    return EINVAL;
+  if (offset + len < 0)
+    return EFBIG;
+
+  /* First thing we have to make sure is that this is really a regular
+     file.  */
+  if (fstat64 (fd, &st) != 0)
+    return EBADF;
+  if (S_ISFIFO (st.st_mode))
+    return ESPIPE;
+  if (! S_ISREG (st.st_mode))
+    return ENODEV;
+
+  if (len == 0)
+    {
+      if (st.st_size < offset)
+	{
+	  int ret = ftruncate64 (fd, offset);
+
+	  if (ret != 0)
+	    ret = errno;
+	  return ret;
+	}
+      return 0;
+    }
+
+  /* We have to know the block size of the filesystem to get at least some
+     sort of performance.  */
+  if (fstatfs64 (fd, &f) != 0)
+    return errno;
+
+  /* Try to play safe.  */
+  if (f.f_bsize == 0)
+    f.f_bsize = 512;
+
+  /* Write something to every block.  */
+  for (offset += (len - 1) % f.f_bsize; len > 0; offset += f.f_bsize)
+    {
+      len -= f.f_bsize;
+
+      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;
+}
+
 extern __typeof(fallocate64) __libc_fallocate64 attribute_hidden;
 int posix_fallocate64(int fd, __off64_t offset, __off64_t len)
 {
-	return __libc_fallocate64(fd, 0, offset, len);
+	int result = __libc_fallocate64(fd, 0, offset, len);
+	if (result != EOPNOTSUPP)
+		return result;
+
+	return internal_fallocate64(fd, offset, len);
 }
 # else
 #  error your machine is neither 32 bit or 64 bit ... it must be magical