Commit 3b6e2723 authored Jul 27, 2012 by Filipe Brandenburger Committed by J. Bruce Fields Jul 27, 2012

locks: prevent side-effects of locks_release_private before file_lock is initialized

When calling fcntl(fd, F_SETLEASE, lck) [with lck=F_WRLCK or F_RDLCK],
the custom signal or owner (if any were previously set using F_SETSIG
or F_SETOWN fcntls) would be reset when F_SETLEASE was called for the
second time on the same file descriptor.

This bug is a regression of 2.6.37 and is described here:
https://bugzilla.kernel.org/show_bug.cgi?id=43336



This patch reverts a commit from Oct 2004 (with subject "nfs4 lease:
move the f_delown processing") which originally introduced the
lm_release_private callback.

Signed-off-by: Filipe Brandenburger <filbranden@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

parent 57c8b13e

fs/locks.c

+6 −11

Original line number	Diff line number	Diff line
		@@ -427,18 +427,8 @@ static void lease_break_callback(struct file_lock *fl)
		kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG);
		}

		static void lease_release_private_callback(struct file_lock *fl)
		{
		if (!fl->fl_file)
		return;

		f_delown(fl->fl_file);
		fl->fl_file->f_owner.signum = 0;
		}

		static const struct lock_manager_operations lease_manager_ops = {
		.lm_break = lease_break_callback,
		.lm_release_private = lease_release_private_callback,
		.lm_change = lease_modify,
		};

		@@ -1155,8 +1145,13 @@ int lease_modify(struct file_lock **before, int arg)
		return error;
		lease_clear_pending(fl, arg);
		locks_wake_up_blocks(fl);
		if (arg == F_UNLCK)
		if (arg == F_UNLCK) {
		struct file *filp = fl->fl_file;

		f_delown(filp);
		filp->f_owner.signum = 0;
		locks_delete_lock(before);
		}
		return 0;
		}