Re: [libvirt] [PATCH] build: avoid compile failure on linux kernels older than 2.6.19

Daniel P. Berrange wrote: > On Mon, May 17, 2010 at 04:25:43PM +0200, Jim Meyering wrote: >> This is required for any kernel prior to 2.6.19, >> since <linux/magic.h> didn't exist back then. >> Now that file is provided by the kernel-headers package. >> >> >From d14ef1669968ffeb65076b007e318934ed99aa61 Mon Sep 17 00:00:00 2001 >> From: Jim Meyering <meyering(a)redhat.com&gt; >> Date: Mon, 17 May 2010 16:17:08 +0200 >> Subject: [PATCH] build: avoid compile failure on linux kernels older than 2.6.19 >> >> * configure.ac: Check for <linux/magic.h>. >> * src/util/storage_file.c: Include <linux/magic.h> only if present. >> Linux kernels prior to 2.6.19 lacked it. >> [__linux__] (NFS_SUPER_MAGIC): Define if not already defined. >> --- >> configure.ac | 2 +- >> src/util/storage_file.c | 7 ++++++- >> 2 files changed, 7 insertions(+), 2 deletions(-) >> >> diff --git a/configure.ac b/configure.ac >> index c187420..ebd2082 100644 >> --- a/configure.ac >> +++ b/configure.ac >> @@ -108,7 +108,7 @@ LIBS=$old_libs >> >> dnl Availability of various common headers (non-fatal if missing). >> AC_CHECK_HEADERS([pwd.h paths.h regex.h sys/syslimits.h \ >> - termios.h sys/poll.h syslog.h mntent.h net/ethernet.h]) >> + termios.h sys/poll.h syslog.h mntent.h net/ethernet.h linux/magic.h]) >> >> dnl Where are the XDR functions? >> dnl If portablexdr is installed, prefer that. >> diff --git a/src/util/storage_file.c b/src/util/storage_file.c >> index 5f15a64..a07bedc 100644 >> --- a/src/util/storage_file.c >> +++ b/src/util/storage_file.c >> @@ -27,7 +27,9 @@ >> #include <unistd.h> >> #include <fcntl.h> >> #ifdef __linux__ >> -# include <linux/magic.h> >> +# if HAVE_LINUX_MAGIC_H >> +# include <linux/magic.h> >> +# endif > > Don't bother with this - just kill this include off completely. It is a > waste of time using it if we can't rely on it existing & have to re-define > everything ourselves. I admit that those numbers will probably never change, but I see including the recommended/modern header as the preferred approach. Then, eventually when the old systems are no longer relevant (yeah, in a long time) we'll be able to remove our hackish define-if-required code.