File systemtap-update-the-runtime-to-handle-a-struct-inode-change.patch of Package systemtap.12680

From: David Smith <dsmith@redhat.com>
Subject: update the runtime to handle a 'struct inode' change
Date: Mon May 23 13:56:29 2016 -0500
Git-commit: 8f888904d8de9a798e4664caa373ea552366b304
References: bsc#1125906
Signed-off-by: Tony Jones <tonyj@suse.de>

    Fix PR20132 by updating the runtime to handle a 'struct inode' change.
    
    * runtime/transport/transport.c (_stp_lock_inode): Use the new inode
      lock/unlock routines.
      (_stp_unlock_inode): Ditto.
    * buildrun.cxx (compile_pass): Add autoconf-inode-rwsem test.
    * runtime/linux/autoconf-inode-rwsem.c: New 'autoconf' test.

diff --git a/buildrun.cxx b/buildrun.cxx
index 8cf4b36b1..27e2be6a2 100644
--- a/buildrun.cxx
+++ b/buildrun.cxx
@@ -321,6 +321,7 @@ compile_pass (systemtap_session& s)
   output_autoconf(s, o, "autoconf-generated-compile.c", "STAPCONF_GENERATED_COMPILE", NULL);
   output_autoconf(s, o, "autoconf-hrtimer-getset-expires.c", "STAPCONF_HRTIMER_GETSET_EXPIRES", NULL);
   output_autoconf(s, o, "autoconf-inode-private.c", "STAPCONF_INODE_PRIVATE", NULL);
+  output_autoconf(s, o, "autoconf-inode-rwsem.c", "STAPCONF_INODE_RWSEM", NULL);
   output_autoconf(s, o, "autoconf-constant-tsc.c", "STAPCONF_CONSTANT_TSC", NULL);
   output_autoconf(s, o, "autoconf-ktime-get-real.c", "STAPCONF_KTIME_GET_REAL", NULL);
   output_autoconf(s, o, "autoconf-x86-uniregs.c", "STAPCONF_X86_UNIREGS", NULL);
diff --git a/runtime/linux/autoconf-inode-rwsem.c b/runtime/linux/autoconf-inode-rwsem.c
new file mode 100644
index 000000000..8ca4a4acc
--- /dev/null
+++ b/runtime/linux/autoconf-inode-rwsem.c
@@ -0,0 +1,5 @@
+#include <linux/fs.h>
+
+// check for 4.6 inode patch which changed i_mutex to i_rwsem
+
+struct inode i  __attribute__ ((unused)) = {.i_rwsem=__RWSEM_INITIALIZER(i.i_rwsem)};
diff --git a/runtime/transport/transport.c b/runtime/transport/transport.c
index bbc61d258..d19eb1ee3 100644
--- a/runtime/transport/transport.c
+++ b/runtime/transport/transport.c
@@ -490,20 +490,28 @@ err0:
 
 static inline void _stp_lock_inode(struct inode *inode)
 {
+#ifdef STAPCONF_INODE_RWSEM
+	inode_lock(inode);
+#else
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 	mutex_lock(&inode->i_mutex);
 #else
 	down(&inode->i_sem);
 #endif
+#endif
 }
 
 static inline void _stp_unlock_inode(struct inode *inode)
 {
+#ifdef STAPCONF_INODE_RWSEM
+	inode_unlock(inode);
+#else
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 	mutex_unlock(&inode->i_mutex);
 #else
 	up(&inode->i_sem);
 #endif
+#endif
 }
 
 static struct dentry *_stp_lockfile = NULL;