From: =?ISO-8859-1?Q?P=E1draig_Brady?= Subject: Re: [PATCH 4/6] Ext4: fail if we try to use hole punch Date: Tue, 16 Nov 2010 16:20:43 +0000 Message-ID: <4CE2AF5B.7020500@draigBrady.com> References: <1289840723-3056-1-git-send-email-josef@redhat.com> <1289840723-3056-5-git-send-email-josef@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: david@fromorbit.com, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com, cmm@us.ibm.com, cluster-devel@redhat.com, ocfs2-devel@oss.oracle.com To: Josef Bacik Return-path: In-Reply-To: <1289840723-3056-5-git-send-email-josef@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On 15/11/10 17:05, Josef Bacik wrote: > Ext4 doesn't have the ability to punch holes yet, so make sure we ret= urn > EOPNOTSUPP if we try to use hole punching through fallocate. This su= pport can > be added later. Thanks, >=20 > Signed-off-by: Josef Bacik > --- > fs/ext4/extents.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) >=20 > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index 0554c48..35bca73 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -3622,6 +3622,10 @@ long ext4_fallocate(struct inode *inode, int m= ode, loff_t offset, loff_t len) > struct ext4_map_blocks map; > unsigned int credits, blkbits =3D inode->i_blkbits; > =20 > + /* We only support the FALLOC_FL_KEEP_SIZE mode */ > + if (mode && (mode !=3D FALLOC_FL_KEEP_SIZE)) > + return -EOPNOTSUPP; > + > /* > * currently supporting (pre)allocate mode for extent-based > * files _only_ So for older versions of ext4 or other filesystems, how do we know that fallocate(...,FALLOC_FL_PUNCH_HOLE) is not supported. I.E. how do we detect at runtime that the call succeeded and didn't just do a normal fallocate()? cheers, P=E1draig.