From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Whitehouse Date: Fri, 30 Oct 2015 14:25:12 +0000 Subject: [Cluster-devel] [GFS2 PATCH v2] GFS2: Protect freeing directory hash table with i_lock spin_lock In-Reply-To: <93040260.67926194.1446148072277.JavaMail.zimbra@redhat.com> References: <93040260.67926194.1446148072277.JavaMail.zimbra@redhat.com> Message-ID: <56337DC8.90205@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 29/10/15 19:47, Bob Peterson wrote: > Hi, > > This is a re-spin of a patch I posted earlier today. > Andy Price pointed out that my comment was wrong: The race concerns > gfs2_evict_inode, not gfs2_clear_inode (as the previous version's > comment indicated). Function gfs2_clear_inode exists in RHEL6 and > earlier, but not in upstream. > > Revised patch description: > > This patch changes function gfs2_dir_hash_inval so it uses the > i_lock spin_lock to protect the in-core hash table, i_hash_cache. > This will prevent double-frees due to a race between gfs2_evict_inode > and inode invalidation. > > Signed-off-by: Bob Peterson > --- > diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c > index 487527b..ad8a5b7 100644 > --- a/fs/gfs2/dir.c > +++ b/fs/gfs2/dir.c > @@ -388,8 +388,13 @@ static __be64 *gfs2_dir_get_hash_table(struct gfs2_inode *ip) > */ > void gfs2_dir_hash_inval(struct gfs2_inode *ip) > { > - __be64 *hc = ip->i_hash_cache; > + __be64 *hc; > + > + spin_lock(&ip->i_inode.i_lock); > + hc = ip->i_hash_cache; > ip->i_hash_cache = NULL; > + spin_unlock(&ip->i_inode.i_lock); > + > kvfree(hc); > } > >