From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Whitehouse Date: Wed, 6 Jul 2016 17:01:25 +0100 Subject: [Cluster-devel] [GFS2 PATCH] GFS2: Check rs_free with rd_rsspin protection In-Reply-To: <1537255470.7048688.1467820347281.JavaMail.zimbra@redhat.com> References: <1537255470.7048688.1467820347281.JavaMail.zimbra@redhat.com> Message-ID: <577D2B55.9090103@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi, Acked-by: Steven Whitehouse Steve. On 06/07/16 16:52, Bob Peterson wrote: > Hi, > > For the last process to close a file opened for write, function > gfs2_rsqa_delete was deleting the file's inode's block reservation > out of the rgrp reservations tree. Then it was checking to make sure > rs_free was 0, but it was performing the check outside the protection > of rd_rsspin spin_lock. The rd_rsspin spin_lock protection is needed > to prevent a race between the process freeing the reservation and > another who is allocating a new set of blocks inside the same rgrp > for the same inode, thus changing its value. > > Signed-off-by: Bob Peterson > > Regards, > > Bob Peterson > Red Hat File Systems > --- > diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c > index fba38ca..86ccc015 100644 > --- a/fs/gfs2/rgrp.c > +++ b/fs/gfs2/rgrp.c > @@ -658,6 +658,7 @@ void gfs2_rs_deltree(struct gfs2_blkreserv *rs) > if (rgd) { > spin_lock(&rgd->rd_rsspin); > __rs_deltree(rs); > + BUG_ON(rs->rs_free); > spin_unlock(&rgd->rd_rsspin); > } > } > @@ -671,10 +672,8 @@ void gfs2_rs_deltree(struct gfs2_blkreserv *rs) > void gfs2_rsqa_delete(struct gfs2_inode *ip, atomic_t *wcount) > { > down_write(&ip->i_rw_mutex); > - if ((wcount == NULL) || (atomic_read(wcount) <= 1)) { > + if ((wcount == NULL) || (atomic_read(wcount) <= 1)) > gfs2_rs_deltree(&ip->i_res); > - BUG_ON(ip->i_res.rs_free); > - } > up_write(&ip->i_rw_mutex); > gfs2_qa_delete(ip, wcount); > } >