diff --git a/ChangeLog b/ChangeLog
index 75c430b..b927022 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,18 @@
 2015-04-24  Florian Weimer  <fweimer@redhat.com>
 
+	* sysdeps/unix/sysv/linux/posix_fallocate.c (posix_fallocate):
+	Assume __ASSUME_FALLOCATE is always true.
+	* sysdeps/unix/sysv/linux/posix_fallocate64.c
+	(__posix_fallocate64_l64): Likweise.
+	* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate.c
+	(posix_fallocate): Likewise.
+	* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate64.c
+	(__posix_fallocate64_l64): Likewise.
+	* sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate.c
+	[!__ASSUME_FALLOCATE]: Add comment.
+
+2015-04-24  Florian Weimer  <fweimer@redhat.com>
+
 	* sysdeps/unix/sysv/linux/i386/Makefile (sysdep_routines) [misc]:
 	Remove call_fallocate.
 	(sysdep_routines) [io]: Add libc-do-syscall.
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate.c b/sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate.c
index be08323..a9c8d73 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate.c
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate.c
@@ -16,42 +16,22 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <fcntl.h>
-#include <kernel-features.h>
 #include <sysdep.h>
 
 #define posix_fallocate static internal_fallocate
 #include <sysdeps/posix/posix_fallocate.c>
 #undef posix_fallocate
 
-#if !defined __ASSUME_FALLOCATE && defined __NR_fallocate
-int __have_fallocate attribute_hidden;
-#endif
-
-
 /* Reserve storage for the data of the file associated with FD.  */
 int
 posix_fallocate (int fd, __off_t offset, __off_t len)
 {
-#ifdef __NR_fallocate
-# ifndef __ASSUME_FALLOCATE
-  if (__builtin_expect (__have_fallocate >= 0, 1))
-# endif
-    {
-      INTERNAL_SYSCALL_DECL (err);
-      int res = INTERNAL_SYSCALL (fallocate, err, 4, fd, 0, offset, len);
-
-      if (! INTERNAL_SYSCALL_ERROR_P (res, err))
-	return 0;
-
-# ifndef __ASSUME_FALLOCATE
-      if (__builtin_expect (INTERNAL_SYSCALL_ERRNO (res, err) == ENOSYS, 0))
-	__have_fallocate = -1;
-      else
-# endif
-	if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
-	  return INTERNAL_SYSCALL_ERRNO (res, err);
-    }
-#endif
+  INTERNAL_SYSCALL_DECL (err);
+  int res = INTERNAL_SYSCALL (fallocate, err, 4, fd, 0, offset, len);
 
+  if (! INTERNAL_SYSCALL_ERROR_P (res, err))
+    return 0;
+  if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
+    return INTERNAL_SYSCALL_ERRNO (res, err);
   return internal_fallocate (fd, offset, len);
 }
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate64.c b/sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate64.c
index 0934550..503e918 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate64.c
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate64.c
@@ -16,7 +16,6 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <fcntl.h>
-#include <kernel-features.h>
 #include <sysdep.h>
 
 extern int __posix_fallocate64_l64 (int fd, __off64_t offset, __off64_t len);
@@ -24,36 +23,16 @@ extern int __posix_fallocate64_l64 (int fd, __off64_t offset, __off64_t len);
 #include <sysdeps/posix/posix_fallocate64.c>
 #undef __posix_fallocate64_l64
 
-#if !defined __ASSUME_FALLOCATE && defined __NR_fallocate
-/* Defined in posix_fallocate.c.  */
-extern int __have_fallocate attribute_hidden;
-#endif
-
-
 /* Reserve storage for the data of the file associated with FD.  */
 int
 __posix_fallocate64_l64 (int fd, __off64_t offset, __off64_t len)
 {
-#ifdef __NR_fallocate
-# ifndef __ASSUME_FALLOCATE
-  if (__builtin_expect (__have_fallocate >= 0, 1))
-# endif
-    {
-      INTERNAL_SYSCALL_DECL (err);
-      int res = INTERNAL_SYSCALL (fallocate, err, 4, fd, 0, offset, len);
-
-      if (! INTERNAL_SYSCALL_ERROR_P (res, err))
-	return 0;
-
-# ifndef __ASSUME_FALLOCATE
-      if (__builtin_expect (INTERNAL_SYSCALL_ERRNO (res, err) == ENOSYS, 0))
-	__have_fallocate = -1;
-      else
-# endif
-	if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
-	  return INTERNAL_SYSCALL_ERRNO (res, err);
-    }
-#endif
+  INTERNAL_SYSCALL_DECL (err);
+  int res = INTERNAL_SYSCALL (fallocate, err, 4, fd, 0, offset, len);
 
+  if (! INTERNAL_SYSCALL_ERROR_P (res, err))
+    return 0;
+  if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
+    return INTERNAL_SYSCALL_ERRNO (res, err);
   return internal_fallocate64 (fd, offset, len);
 }
diff --git a/sysdeps/unix/sysv/linux/posix_fallocate.c b/sysdeps/unix/sysv/linux/posix_fallocate.c
index 13d4afd..4587029 100644
--- a/sysdeps/unix/sysv/linux/posix_fallocate.c
+++ b/sysdeps/unix/sysv/linux/posix_fallocate.c
@@ -16,44 +16,24 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <fcntl.h>
-#include <kernel-features.h>
 #include <sysdep.h>
 
 #define posix_fallocate static internal_fallocate
 #include <sysdeps/posix/posix_fallocate.c>
 #undef posix_fallocate
 
-#if !defined __ASSUME_FALLOCATE && defined __NR_fallocate
-int __have_fallocate attribute_hidden;
-#endif
-
-
 /* Reserve storage for the data of the file associated with FD.  */
 int
 posix_fallocate (int fd, __off_t offset, __off_t len)
 {
-#ifdef __NR_fallocate
-# ifndef __ASSUME_FALLOCATE
-  if (__glibc_likely (__have_fallocate >= 0))
-# endif
-    {
-      INTERNAL_SYSCALL_DECL (err);
-      int res = INTERNAL_SYSCALL (fallocate, err, 6, fd, 0,
-				  __LONG_LONG_PAIR (offset >> 31, offset),
-				  __LONG_LONG_PAIR (len >> 31, len));
-
-      if (! INTERNAL_SYSCALL_ERROR_P (res, err))
-	return 0;
-
-# ifndef __ASSUME_FALLOCATE
-      if (__glibc_unlikely (INTERNAL_SYSCALL_ERRNO (res, err) == ENOSYS))
-	__have_fallocate = -1;
-      else
-# endif
-	if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
-	  return INTERNAL_SYSCALL_ERRNO (res, err);
-    }
-#endif
-
+  INTERNAL_SYSCALL_DECL (err);
+  int res = INTERNAL_SYSCALL (fallocate, err, 6, fd, 0,
+			      __LONG_LONG_PAIR (offset >> 31, offset),
+			      __LONG_LONG_PAIR (len >> 31, len));
+
+  if (! INTERNAL_SYSCALL_ERROR_P (res, err))
+    return 0;
+  if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
+    return INTERNAL_SYSCALL_ERRNO (res, err);
   return internal_fallocate (fd, offset, len);
 }
diff --git a/sysdeps/unix/sysv/linux/posix_fallocate64.c b/sysdeps/unix/sysv/linux/posix_fallocate64.c
index 9545459..771e59c 100644
--- a/sysdeps/unix/sysv/linux/posix_fallocate64.c
+++ b/sysdeps/unix/sysv/linux/posix_fallocate64.c
@@ -16,7 +16,6 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <fcntl.h>
-#include <kernel-features.h>
 #include <sysdep.h>
 
 extern int __posix_fallocate64_l64 (int fd, __off64_t offset, __off64_t len);
@@ -24,40 +23,20 @@ extern int __posix_fallocate64_l64 (int fd, __off64_t offset, __off64_t len);
 #include <sysdeps/posix/posix_fallocate64.c>
 #undef __posix_fallocate64_l64
 
-#if !defined __ASSUME_FALLOCATE && defined __NR_fallocate
-/* Defined in posix_fallocate.c.  */
-extern int __have_fallocate attribute_hidden;
-#endif
-
-
 /* Reserve storage for the data of the file associated with FD.  */
 int
 __posix_fallocate64_l64 (int fd, __off64_t offset, __off64_t len)
 {
-#ifdef __NR_fallocate
-# ifndef __ASSUME_FALLOCATE
-  if (__glibc_likely (__have_fallocate >= 0))
-# endif
-    {
-      INTERNAL_SYSCALL_DECL (err);
-      int res = INTERNAL_SYSCALL (fallocate, err, 6, fd, 0,
-				  __LONG_LONG_PAIR ((long int) (offset >> 32),
-						    (long int) offset),
-				  __LONG_LONG_PAIR ((long int) (len >> 32),
-						    (long int) len));
-
-      if (! INTERNAL_SYSCALL_ERROR_P (res, err))
-	return 0;
-
-# ifndef __ASSUME_FALLOCATE
-      if (__glibc_unlikely (INTERNAL_SYSCALL_ERRNO (res, err) == ENOSYS))
-	__have_fallocate = -1;
-      else
-# endif
-	if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
-	  return INTERNAL_SYSCALL_ERRNO (res, err);
-    }
-#endif
-
+  INTERNAL_SYSCALL_DECL (err);
+  int res = INTERNAL_SYSCALL (fallocate, err, 6, fd, 0,
+			      __LONG_LONG_PAIR ((long int) (offset >> 32),
+						(long int) offset),
+			      __LONG_LONG_PAIR ((long int) (len >> 32),
+						(long int) len));
+
+  if (! INTERNAL_SYSCALL_ERROR_P (res, err))
+    return 0;
+  if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
+    return INTERNAL_SYSCALL_ERRNO (res, err);
   return internal_fallocate64 (fd, offset, len);
 }
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate.c b/sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate.c
index ecc6505..8ae8a29 100644
--- a/sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate.c
+++ b/sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate.c
@@ -23,6 +23,8 @@
 #include <sysdeps/posix/posix_fallocate.c>
 #undef posix_fallocate
 
+/* The alpha architecture introduced the fallocate system call in
+   2.6.33-rc1, so we still need the fallback code.  */
 #if !defined __ASSUME_FALLOCATE && defined __NR_fallocate
 static int __have_fallocate;
 #endif
