locks: rename file-private locks to "open file description locks"

File-private locks have been merged into Linux for v3.15, and *now*
people are commenting that the name and macro definitions for the new
file-private locks suck.

...and I can't even disagree. The names and command macros do suck.

We're going to have to live with these for a long time, so it's
important that we be happy with the names before we're stuck with them.
The consensus on the lists so far is that they should be rechristened as
"open file description locks".

The name isn't a big deal for the kernel, but the command macros are not
visually distinct enough from the traditional POSIX lock macros. The
glibc and documentation folks are recommending that we change them to
look like F_OFD_{GETLK|SETLK|SETLKW}. That lessens the chance that a
programmer will typo one of the commands wrong, and also makes it easier
to spot this difference when reading code.

This patch makes the following changes that I think are necessary before
v3.15 ships:

1) rename the command macros to their new names. These end up in the uapi
   headers and so are part of the external-facing API. It turns out that
   glibc doesn't actually use the fcntl.h uapi header, but it's hard to
   be sure that something else won't. Changing it now is safest.

2) make the the /proc/locks output display these as type "OFDLCK"

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Carlos O'Donell <carlos@redhat.com>
Cc: Stefan Metzmacher <metze@samba.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Frank Filz <ffilzlnx@mindspring.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
diff --git a/fs/locks.c b/fs/locks.c
index b380f55..e1023b5 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1941,7 +1941,7 @@
 	if (error)
 		goto out;
 
-	if (cmd == F_GETLKP) {
+	if (cmd == F_OFD_GETLK) {
 		error = -EINVAL;
 		if (flock.l_pid != 0)
 			goto out;
@@ -2076,7 +2076,7 @@
 	 * FL_FILE_PVT flag and override the owner.
 	 */
 	switch (cmd) {
-	case F_SETLKP:
+	case F_OFD_SETLK:
 		error = -EINVAL;
 		if (flock.l_pid != 0)
 			goto out;
@@ -2085,7 +2085,7 @@
 		file_lock->fl_flags |= FL_FILE_PVT;
 		file_lock->fl_owner = (fl_owner_t)filp;
 		break;
-	case F_SETLKPW:
+	case F_OFD_SETLKW:
 		error = -EINVAL;
 		if (flock.l_pid != 0)
 			goto out;
@@ -2143,7 +2143,7 @@
 	if (error)
 		goto out;
 
-	if (cmd == F_GETLKP) {
+	if (cmd == F_OFD_GETLK) {
 		error = -EINVAL;
 		if (flock.l_pid != 0)
 			goto out;
@@ -2211,7 +2211,7 @@
 	 * FL_FILE_PVT flag and override the owner.
 	 */
 	switch (cmd) {
-	case F_SETLKP:
+	case F_OFD_SETLK:
 		error = -EINVAL;
 		if (flock.l_pid != 0)
 			goto out;
@@ -2220,7 +2220,7 @@
 		file_lock->fl_flags |= FL_FILE_PVT;
 		file_lock->fl_owner = (fl_owner_t)filp;
 		break;
-	case F_SETLKPW:
+	case F_OFD_SETLKW:
 		error = -EINVAL;
 		if (flock.l_pid != 0)
 			goto out;
@@ -2413,7 +2413,7 @@
 		if (fl->fl_flags & FL_ACCESS)
 			seq_printf(f, "ACCESS");
 		else if (IS_FILE_PVT(fl))
-			seq_printf(f, "FLPVT ");
+			seq_printf(f, "OFDLCK");
 		else
 			seq_printf(f, "POSIX ");