X wcfs/fusetrace: Update to recent bpftrace

- don't need to manually declare iov_iter struct
- can use enums
- have to use `struct` in casts.

wcfs/fusetrace

 #!/usr/bin/env -S bpftrace
-// Copyright (C) 2019  Nexedi SA and Contributors.
-//                     Kirill Smelkov <kirr@nexedi.com>
+// Copyright (C) 2019-2020  Nexedi SA and Contributors.
+//                          Kirill Smelkov <kirr@nexedi.com>
 //
 // This program is free software: you can Use, Study, Modify and Redistribute
 // it under the terms of the GNU General Public License version 3, or (at your
@@ -24,26 +24,6 @@
 #include <linux/fuse.h>
 #include <linux/uio.h>
 
-// FIXME https://github.com/iovisor/bpftrace/issues/406
-struct xiov_iter {
-        unsigned int type;
-        size_t iov_offset;
-        size_t count;
-        union {
-                struct iovec *iov;
-                struct kvec *kvec;
-                struct bio_vec *bvec;
-                struct pipe_inode_info *pipe;
-        };
-        union {
-                unsigned long nr_segs;
-                struct {
-                        int idx;
-                        int start_idx;
-                };
-        };
-};
-
 
 BEGIN {
 	@tstart = nsecs;
@@ -58,59 +38,59 @@ BEGIN {
 	//clear(@rpending);	// {} (tid,#nr) -> ustack
 	//clear(@wpending);	// {} (tid,#nw) -> ustack
 
-	// XXX bpftrace does not recognize enum
-	@opcode[ 1] = "LOOKUP";
-	@opcode[ 2] = "FORGET";
-	@opcode[ 3] = "GETATTR";
-	@opcode[ 4] = "SETATTR";
-	@opcode[ 5] = "READLINK";
-	@opcode[ 6] = "SYMLINK";
-	@opcode[ 8] = "MKNOD";
-	@opcode[ 9] = "MKDIR";
-	@opcode[10] = "UNLINK";
-	@opcode[11] = "RMDIR";
-	@opcode[12] = "RENAME";
-	@opcode[13] = "LINK";
-	@opcode[14] = "OPEN";
-	@opcode[15] = "READ";
-	@opcode[16] = "WRITE";
-	@opcode[17] = "STATFS";
-	@opcode[18] = "RELEASE";
-	@opcode[20] = "FSYNC";
-	@opcode[21] = "SETXATTR";
-	@opcode[22] = "GETXATTR";
-	@opcode[23] = "LISTXATTR";
-	@opcode[24] = "REMOVEXATTR";
-	@opcode[25] = "FLUSH";
-	@opcode[26] = "INIT";
-	@opcode[27] = "OPENDIR";
-	@opcode[28] = "READDIR";
-	@opcode[29] = "RELEASEDIR";
-	@opcode[30] = "FSYNCDIR";
-	@opcode[31] = "GETLK";
-	@opcode[32] = "SETLK";
-	@opcode[33] = "SETLKW";
-	@opcode[34] = "ACCESS";
-	@opcode[35] = "CREATE";
-	@opcode[36] = "INTERRUPT";
-	@opcode[37] = "BMAP";
-	@opcode[38] = "DESTROY";
-	@opcode[39] = "IOCTL";
-	@opcode[40] = "POLL";
-	@opcode[41] = "NOTIFY_REPLY";
-	@opcode[42] = "BATCH_FORGET";
-	@opcode[43] = "FALLOCATE";
-	@opcode[44] = "READDIRPLUS";
-	@opcode[45] = "RENAME2";
-	@opcode[46] = "LSEEK";
-	@opcode[47] = "COPY_FILE_RANGE";
-
-	@notify[1] = "NOTIFY_POLL";
-	@notify[2] = "NOTIFY_INVAL_INODE";
-	@notify[3] = "NOTIFY_INVAL_ENTRY";
-	@notify[4] = "NOTIFY_STORE";
-	@notify[5] = "NOTIFY_RETRIEVE";
-	@notify[6] = "NOTIFY_DELETE";
+	@opcode [FUSE_LOOKUP]		= "LOOKUP";
+	@opcode [FUSE_FORGET]		= "FORGET";
+	@opcode [FUSE_GETATTR]		= "GETATTR";
+	@opcode [FUSE_SETATTR]		= "SETATTR";
+	@opcode [FUSE_READLINK]		= "READLINK";
+	@opcode [FUSE_SYMLINK]		= "SYMLINK";
+	@opcode [FUSE_MKNOD]		= "MKNOD";
+	@opcode [FUSE_MKDIR]		= "MKDIR";
+	@opcode [FUSE_UNLINK]		= "UNLINK";
+	@opcode [FUSE_RMDIR]		= "RMDIR";
+	@opcode [FUSE_RENAME]		= "RENAME";
+	@opcode [FUSE_LINK]		= "LINK";
+	@opcode [FUSE_OPEN]		= "OPEN";
+	@opcode [FUSE_READ]		= "READ";
+	@opcode [FUSE_WRITE]		= "WRITE";
+	@opcode [FUSE_STATFS]		= "STATFS";
+	@opcode [FUSE_RELEASE]		= "RELEASE";
+	@opcode [FUSE_FSYNC]		= "FSYNC";
+	@opcode [FUSE_SETXATTR]		= "SETXATTR";
+	@opcode [FUSE_GETXATTR]		= "GETXATTR";
+	@opcode [FUSE_LISTXATTR] 	= "LISTXATTR";
+	@opcode [FUSE_REMOVEXATTR]	= "REMOVEXATTR";
+	@opcode [FUSE_FLUSH]		= "FLUSH";
+	@opcode [FUSE_INIT]		= "INIT";
+	@opcode [FUSE_OPENDIR]		= "OPENDIR";
+	@opcode [FUSE_READDIR]		= "READDIR";
+	@opcode [FUSE_RELEASEDIR]	= "RELEASEDIR";
+	@opcode [FUSE_FSYNCDIR]		= "FSYNCDIR";
+	@opcode [FUSE_GETLK]		= "GETLK";
+	@opcode [FUSE_SETLK]		= "SETLK";
+	@opcode [FUSE_SETLKW]		= "SETLKW";
+	@opcode [FUSE_ACCESS]		= "ACCESS";
+	@opcode [FUSE_CREATE]		= "CREATE";
+	@opcode [FUSE_INTERRUPT]	= "INTERRUPT";
+	@opcode [FUSE_BMAP]		= "BMAP";
+	@opcode [FUSE_DESTROY]		= "DESTROY";
+	@opcode [FUSE_IOCTL]		= "IOCTL";
+	@opcode [FUSE_POLL]		= "POLL";
+	@opcode [FUSE_NOTIFY_REPLY]	= "NOTIFY_REPLY";
+	@opcode [FUSE_BATCH_FORGET]	= "BATCH_FORGET";
+	@opcode [FUSE_FALLOCATE]	= "FALLOCATE";
+	@opcode [FUSE_READDIRPLUS]	= "READDIRPLUS";
+	@opcode [FUSE_RENAME2]		= "RENAME2";
+	@opcode [FUSE_LSEEK]		= "LSEEK";
+	// XXX >= Linux x
+	//@opcode[FUSE_COPY_FILE_RANGE] = "COPY_FILE_RANGE";
+
+	@notify [FUSE_NOTIFY_POLL]		= "NOTIFY_POLL";
+	@notify [FUSE_NOTIFY_INVAL_INODE]	= "NOTIFY_INVAL_INODE";
+	@notify [FUSE_NOTIFY_INVAL_ENTRY]	= "NOTIFY_INVAL_ENTRY";
+	@notify [FUSE_NOTIFY_STORE]		= "NOTIFY_STORE";
+	@notify [FUSE_NOTIFY_RETRIEVE]		= "NOTIFY_RETRIEVE";
+	@notify [FUSE_NOTIFY_DELETE]		= "NOTIFY_DELETE";
 }
 
 END {
@@ -133,7 +113,7 @@ kprobe::fuse_dev_read {
 	@rpending[tid,$nr] = ustack;
 
 	// fuse_dev_do_read advances `to` - fetch/remember buffer pointer before.
-	$to = (xiov_iter *)arg1;
+	$to = (struct iov_iter *)arg1;
 	$buf = $to->iov->iov_base;
 	@rbuf[tid] = $buf;
 
@@ -149,7 +129,7 @@ kretprobe::fuse_dev_read {
 	@nread[tid] = $rr + 1;
 	delete(@rpending[tid,$rr]);
 
-	$h = (fuse_in_header *)@rbuf[tid];
+	$h = (struct fuse_in_header *)@rbuf[tid];
 	delete(@rbuf[tid]);
 
 	$op = @opcode[$h->opcode];
@@ -165,9 +145,9 @@ kprobe::fuse_dev_write {
 	$nw = @nwrite[tid];
 	@wpending[tid,$nw] = ustack;
 
-	$from = (xiov_iter *)arg1;
+	$from = (struct iov_iter *)arg1;
 	$wbuf = $from->iov->iov_base;
-	$wh = (fuse_out_header *)$wbuf;
+	$wh = (struct fuse_out_header *)$wbuf;
 
 	printf("P%d %d.%d /dev/fuse <- write      %s/%d_%d_w:\n", cpu, $tw/1000000, $tw%1000000, comm, tid, $nw);