tools lib api fs: Add hugetlbfs filesystem detector

Detect hugetlbfs. hugetlbfs__mountpoint() will be used during recording
to help identifying hugetlb mmaps: which should be recognized as anon
mapping.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Reviewed-by: Nilay Vaish <nilayvaish@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Hou Pengyang <houpengyang@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1473137909-142064-3-git-send-email-wangnan0@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/api/fs/fs.c

@@ -34,6 +34,10 @@
 #define TRACEFS_MAGIC          0x74726163
 #endif
 
+#ifndef HUGETLBFS_MAGIC
+#define HUGETLBFS_MAGIC        0x958458f6
+#endif
+
 static const char * const sysfs__fs_known_mountpoints[] = {
 	"/sys",
 	0,
@@ -67,6 +71,10 @@ static const char * const tracefs__known_mountpoints[] = {
 	0,
 };
 
+static const char * const hugetlbfs__known_mountpoints[] = {
+	0,
+};
+
 struct fs {
 	const char		*name;
 	const char * const	*mounts;
@@ -80,6 +88,7 @@ enum {
 	FS__PROCFS  = 1,
 	FS__DEBUGFS = 2,
 	FS__TRACEFS = 3,
+	FS__HUGETLBFS = 4,
 };
 
 #ifndef TRACEFS_MAGIC
@@ -107,6 +116,11 @@ static struct fs fs__entries[] = {
 		.mounts	= tracefs__known_mountpoints,
 		.magic	= TRACEFS_MAGIC,
 	},
+	[FS__HUGETLBFS] = {
+		.name	= "hugetlbfs",
+		.mounts = hugetlbfs__known_mountpoints,
+		.magic	= HUGETLBFS_MAGIC,
+	},
 };
 
 static bool fs__read_mounts(struct fs *fs)
@@ -265,6 +279,7 @@ FS(sysfs,   FS__SYSFS);
 FS(procfs,  FS__PROCFS);
 FS(debugfs, FS__DEBUGFS);
 FS(tracefs, FS__TRACEFS);
+FS(hugetlbfs, FS__HUGETLBFS);
 
 int filename__read_int(const char *filename, int *value)
 {

tools/lib/api/fs/fs.h

@@ -21,6 +21,7 @@ FS(sysfs)
 FS(procfs)
 FS(debugfs)
 FS(tracefs)
+FS(hugetlbfs)
 
 #undef FS