tools lib api fs: Add bpf_fs filesystem detector

Allow mounting of the BPF filesystem at /sys/fs/bpf.

Signed-off-by: Joe Stringer <[e-mail]>
Cc: Alexei Starovoitov <[e-mail]>
Cc: Daniel Borkmann <[e-mail]>
Cc: Wang Nan <[e-mail]>
Cc: [e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/lib/api/fs/fs.c

···
 #define HUGETLBFS_MAGIC        0x958458f6
 #endif
 
+#ifndef BPF_FS_MAGIC
+#define BPF_FS_MAGIC           0xcafe4a11
+#endif
+
 static const char * const sysfs__fs_known_mountpoints[] = {
 	"/sys",
 	0,
···
 	0,
 };
 
+static const char * const bpf_fs__known_mountpoints[] = {
+	"/sys/fs/bpf",
+	0,
+};
+
 struct fs {
 	const char		*name;
 	const char * const	*mounts;
···
 	FS__DEBUGFS = 2,
 	FS__TRACEFS = 3,
 	FS__HUGETLBFS = 4,
+	FS__BPF_FS = 5,
 };
 
 #ifndef TRACEFS_MAGIC
···
 		.name	= "hugetlbfs",
 		.mounts = hugetlbfs__known_mountpoints,
 		.magic	= HUGETLBFS_MAGIC,
+	},
+	[FS__BPF_FS] = {
+		.name	= "bpf",
+		.mounts = bpf_fs__known_mountpoints,
+		.magic	= BPF_FS_MAGIC,
 	},
 };
 
···
 FS(debugfs, FS__DEBUGFS);
 FS(tracefs, FS__TRACEFS);
 FS(hugetlbfs, FS__HUGETLBFS);
+FS(bpf_fs, FS__BPF_FS);
 
 int filename__read_int(const char *filename, int *value)
 {

tools/lib/api/fs/fs.h

···
 FS(debugfs)
 FS(tracefs)
 FS(hugetlbfs)
+FS(bpf_fs)
 
 #undef FS