locks: ensure that fl_owner is always initialized properly in flock and lease codepaths

Currently, the fl_owner isn't set for flock locks. Some filesystems use
byte-range locks to simulate flock locks and there is a common idiom in
those that does:

fl->fl_owner = (fl_owner_t)filp;
fl->fl_start = 0;
fl->fl_end = OFFSET_MAX;

Since flock locks are generally "owned" by the open file description,
move this into the common flock lock setup code. The fl_start and fl_end
fields are already set appropriately, so remove the unneeded setting of
that in flock ops in those filesystems as well.

Finally, the lease code also sets the fl_owner as if they were owned by
the process and not the open file description. This is incorrect as
leases have the same ownership semantics as flock locks. Set them the
same way. The lease code doesn't actually use the fl_owner value for
anything, so this is more for consistency's sake than a bugfix.

Reported-by: Trond Myklebust <[e-mail]>
Signed-off-by: Jeff Layton <[e-mail]>
Acked-by: Greg Kroah-Hartman <[e-mail]> (Staging portion)
Acked-by: J. Bruce Fields <[e-mail]>

drivers/staging/lustre/lustre/llite/file.c

···
 
 	ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_FLOCK, 1);
 
-	if (file_lock->fl_flags & FL_FLOCK) {
+	if (file_lock->fl_flags & FL_FLOCK)
 		LASSERT((cmd == F_SETLKW) || (cmd == F_SETLK));
-		/* flocks are whole-file locks */
-		flock.l_flock.end = OFFSET_MAX;
-		/* For flocks owner is determined by the local file descriptor*/
-		flock.l_flock.owner = (unsigned long)file_lock->fl_file;
-	} else if (file_lock->fl_flags & FL_POSIX) {
-		flock.l_flock.owner = (unsigned long)file_lock->fl_owner;
-		flock.l_flock.start = file_lock->fl_start;
-		flock.l_flock.end = file_lock->fl_end;
-	} else {
+	else if (!(file_lock->fl_flags & FL_POSIX))
 		return -EINVAL;
-	}
+
+	flock.l_flock.owner = (unsigned long)file_lock->fl_owner;
 	flock.l_flock.pid = file_lock->fl_pid;
+	flock.l_flock.start = file_lock->fl_start;
+	flock.l_flock.end = file_lock->fl_end;
 
 	/* Somewhat ugly workaround for svc lockd.
 	 * lockd installs custom fl_lmops->lm_compare_owner that checks

fs/9p/vfs_file.c

···
 		invalidate_mapping_pages(&inode->i_data, 0, -1);
 	}
 	/* Convert flock to posix lock */
-	fl->fl_owner = (fl_owner_t)filp;
-	fl->fl_start = 0;
-	fl->fl_end = OFFSET_MAX;
 	fl->fl_flags |= FL_POSIX;
 	fl->fl_flags ^= FL_FLOCK;
 

fs/afs/flock.c

···
 		return -ENOLCK;
 
 	/* we're simulating flock() locks using posix locks on the server */
-	fl->fl_owner = (fl_owner_t) file;
-	fl->fl_start = 0;
-	fl->fl_end = OFFSET_MAX;
-
 	if (fl->fl_type == F_UNLCK)
 		return afs_do_unlk(file, fl);
 	return afs_do_setlk(file, fl);

fs/ceph/locks.c

···
 	else
 		length = fl->fl_end - fl->fl_start + 1;
 
-	if (lock_type == CEPH_LOCK_FCNTL)
-		owner = secure_addr(fl->fl_owner);
-	else
-		owner = secure_addr(fl->fl_file);
+	owner = secure_addr(fl->fl_owner);
 
 	dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, "
 	     "start: %llu, length: %llu, wait: %d, type: %d", (int)lock_type,
···
 	cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1);
 	cephlock->client = cpu_to_le64(0);
 	cephlock->pid = cpu_to_le64((u64)lock->fl_pid);
-	if (lock->fl_flags & FL_POSIX)
-		cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner));
-	else
-		cephlock->owner = cpu_to_le64(secure_addr(lock->fl_file));
+	cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner));
 
 	switch (lock->fl_type) {
 	case F_RDLCK:

fs/fuse/file.c

···
 		struct fuse_file *ff = file->private_data;
 
 		/* emulate flock with POSIX locks */
-		fl->fl_owner = (fl_owner_t) file;
 		ff->flock = true;
 		err = fuse_setlk(file, fl, 1);
 	}

fs/locks.c

···
 		return -ENOMEM;
 
 	fl->fl_file = filp;
+	fl->fl_owner = (fl_owner_t)filp;
 	fl->fl_pid = current->tgid;
 	fl->fl_flags = FL_FLOCK;
 	fl->fl_type = type;
···
 	if (assign_type(fl, type) != 0)
 		return -EINVAL;
 
-	fl->fl_owner = current->files;
+	fl->fl_owner = (fl_owner_t)filp;
 	fl->fl_pid = current->tgid;
 
 	fl->fl_file = filp;
···
 
 	if (filp->f_op->flock) {
 		struct file_lock fl = {
+			.fl_owner = (fl_owner_t)filp,
 			.fl_pid = current->tgid,
 			.fl_file = filp,
 			.fl_flags = FL_FLOCK,

fs/nfs/file.c

···
 		is_local = 1;
 
 	/* We're simulating flock() locks using posix locks on the server */
-	fl->fl_owner = (fl_owner_t)filp;
-	fl->fl_start = 0;
-	fl->fl_end = OFFSET_MAX;
-
 	if (fl->fl_type == F_UNLCK)
 		return do_unlk(filp, cmd, fl, is_local);
 	return do_setlk(filp, cmd, fl, is_local);