From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id E18E57F6D for ; Wed, 25 Jun 2014 23:53:36 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay1.corp.sgi.com (Postfix) with ESMTP id B80978F8054 for ; Wed, 25 Jun 2014 21:53:36 -0700 (PDT) Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id ofuuVWptODoYITyB for ; Wed, 25 Jun 2014 21:53:34 -0700 (PDT) Date: Thu, 26 Jun 2014 14:52:56 +1000 From: Dave Chinner Subject: Re: [PATCH 5/6] xfs: add log attributes for log lsn and grant head data Message-ID: <20140626045256.GY4453@dastard> References: <1402060414-22075-1-git-send-email-bfoster@redhat.com> <1402060414-22075-6-git-send-email-bfoster@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1402060414-22075-6-git-send-email-bfoster@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Brian Foster Cc: xfs@oss.sgi.com On Fri, Jun 06, 2014 at 09:13:33AM -0400, Brian Foster wrote: > Create log attributes to export the current runtime state of the log to > sysfs. Note that the filesystem should be frozen for consistency across > attributes. > > The following per-mount attributes are created: log_head_lsn, > log_tail_lsn, reserve_grant_head and write_grant_head. These represent > the physical log head, tail and reserve and write grant heads > respectively. Attribute values are exported in the following format: > > "cycle:[block,byte]" > > ... where cycle represents the log cycle and [block,bytes] represents > either the basic block or byte offset of the log, depending on the > attribute. Log sequence number (LSN) values are encoded in basic blocks > and grant heads are encoded in bytes. All values are in decimal format. > > Signed-off-by: Brian Foster > --- > fs/xfs/xfs_sysfs.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 66 insertions(+) > > diff --git a/fs/xfs/xfs_sysfs.c b/fs/xfs/xfs_sysfs.c > index f837527..fbd82d5 100644 > --- a/fs/xfs/xfs_sysfs.c > +++ b/fs/xfs/xfs_sysfs.c > @@ -23,6 +23,9 @@ > #include "xfs_trans_resv.h" > #include "xfs_ag.h" > #include "xfs_mount.h" > +#include "xfs_log_format.h" > +#include "xfs_log.h" > +#include "xfs_log_priv.h" > > struct xfs_sysfs_attr { > struct attribute attr; > @@ -57,7 +60,70 @@ struct kobj_type xfs_mp_ktype = { > > /* xlog */ > > +STATIC ssize_t > +log_head_lsn_show( > + char *buf, > + void *data) > +{ > + struct xlog *log = data; > + int ret; > + > + spin_lock(&log->l_icloglock); > + ret = snprintf(buf, PAGE_SIZE, "%d:%d\n", log->l_curr_cycle, > + log->l_curr_block); > + spin_unlock(&log->l_icloglock); I'd keep the snprintf() outside the iclog lock, just so sampling perturbs behaviour as little as possible. i.e. use cycle/block locals as per all the others. Otherwise, looks good. Reviewed-by: Dave Chinner -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs