From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zeniv.linux.org.uk ([195.92.253.2]:42619 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754828AbcCBUMQ (ORCPT ); Wed, 2 Mar 2016 15:12:16 -0500 Date: Wed, 2 Mar 2016 20:12:15 +0000 From: Al Viro To: Frank Sorenson Cc: linux-fsdevel@vger.kernel.org, dwysocha@redhat.com, lvaz@redhat.com Subject: Re: [PATCH 3/5] fs: add trace events for freeze_super() and thaw_super() Message-ID: <20160302201215.GL17997@ZenIV.linux.org.uk> References: <1456945319-16283-1-git-send-email-sorenson@redhat.com> <1456945319-16283-4-git-send-email-sorenson@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1456945319-16283-4-git-send-email-sorenson@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, Mar 02, 2016 at 01:01:57PM -0600, Frank Sorenson wrote: > There is currently no visibility into when or how > a filesystem became frozen, and no record of freeze/ > thaw activity. Add tracepoints for these events. NAK. > + TP_fast_assign( > + memcpy(__entry->comm, current->comm, TASK_COMM_LEN); > + memcpy(__entry->super_id, sb->s_id, SUPER_ID_MAX_LEN); > + memcpy(__entry->fstype, sb->s_type->name, FSTYPE_MAX_LEN); > + __entry->dev = sb->s_dev; > + __entry->frozen = sb->s_writers.frozen; This turns the value of ->s_writers.frozen into a fucking userland ABI. Committing us to maintain it forever. No, thanks. BTW, how is your "record the pid" supposed to interact with containers and pidns?