perf fs: Add procfs support

Adding procfs support into fs class.

The interface function:
  const char *procfs__mountpoint(void);

provides existing mountpoint path for procfs.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1383660887-1734-3-git-send-email-jolsa@redhat.com
[ Fixup namespace ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/fs.c

@@ -9,6 +9,11 @@ static const char * const sysfs__fs_known_mountpoints[] = {
 	0,
 };
 
+static const char * const procfs__known_mountpoints[] = {
+	"/proc",
+	0,
+};
+
 struct fs {
 	const char		*name;
 	const char * const	*mounts;
@@ -18,7 +23,8 @@ struct fs {
 };
 
 enum {
-	FS__SYSFS = 0,
+	FS__SYSFS  = 0,
+	FS__PROCFS = 1,
 };
 
 static struct fs fs__entries[] = {
@@ -27,6 +33,11 @@ static struct fs fs__entries[] = {
 		.mounts	= sysfs__fs_known_mountpoints,
 		.magic	= SYSFS_MAGIC,
 	},
+	[FS__PROCFS] = {
+		.name	= "proc",
+		.mounts	= procfs__known_mountpoints,
+		.magic	= PROC_SUPER_MAGIC,
+	},
 };
 
 static bool fs__read_mounts(struct fs *fs)
@@ -104,4 +115,5 @@ const char *name##__mountpoint(void)	\
 	return fs__mountpoint(idx);	\
 }
 
-FS__MOUNTPOINT(sysfs, FS__SYSFS);
+FS__MOUNTPOINT(sysfs,  FS__SYSFS);
+FS__MOUNTPOINT(procfs, FS__PROCFS);

tools/perf/util/fs.h

@@ -2,5 +2,6 @@
 #define __PERF_FS
 
 const char *sysfs__mountpoint(void);
+const char *procfs__mountpoint(void);
 
 #endif /* __PERF_FS */

tools/perf/util/include/linux/magic.h

@@ -9,4 +9,8 @@
 #define SYSFS_MAGIC            0x62656572
 #endif
 
+#ifndef PROC_SUPER_MAGIC
+#define PROC_SUPER_MAGIC       0x9fa0
+#endif
+
 #endif