From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: [PATCH v7 11/17] locks: report l_pid as -1 for FL_FILE_PVT locks Date: Mon, 24 Mar 2014 20:30:04 -0400 Message-ID: <20140325003004.GG12979@fieldses.org> References: <1395261961-10855-1-git-send-email-jlayton@redhat.com> <1395261961-10855-12-git-send-email-jlayton@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: viro@ZenIV.linux.org.uk, linux-fsdevel@vger.kernel.org To: Jeff Layton Return-path: Received: from fieldses.org ([174.143.236.118]:54095 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750875AbaCYAaK (ORCPT ); Mon, 24 Mar 2014 20:30:10 -0400 Content-Disposition: inline In-Reply-To: <1395261961-10855-12-git-send-email-jlayton@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, Mar 19, 2014 at 04:45:55PM -0400, Jeff Layton wrote: > FL_FILE_PVT locks are no longer tied to a particular pid, and are > instead inheritable by child processes. Report a l_pid of '-1' for > these sorts of locks since the pid is somewhat meaningless for them. > > This precedent comes from FreeBSD. There, POSIX and flock() locks can > conflict with one another. If fcntl(F_GETLK, ...) returns a lock set > with flock() then the l_pid member cannot be a process ID because the > lock is not held by a process as such. ACK.--b. > > Signed-off-by: Jeff Layton > --- > fs/locks.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/locks.c b/fs/locks.c > index f1b9b149dd39..5953b2cdef9c 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -1864,7 +1864,7 @@ EXPORT_SYMBOL_GPL(vfs_test_lock); > > static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) > { > - flock->l_pid = fl->fl_pid; > + flock->l_pid = IS_FILE_PVT(fl) ? -1 : fl->fl_pid; > #if BITS_PER_LONG == 32 > /* > * Make sure we can represent the posix lock via > @@ -1886,7 +1886,7 @@ static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) > #if BITS_PER_LONG == 32 > static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) > { > - flock->l_pid = fl->fl_pid; > + flock->l_pid = IS_FILE_PVT(fl) ? -1 : fl->fl_pid; > flock->l_start = fl->fl_start; > flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : > fl->fl_end - fl->fl_start + 1; > -- > 1.8.5.3 >