From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Durgin Subject: Re: [PATCH 11/16] rbd: dynamically allocate snapshot name Date: Wed, 11 Jul 2012 13:53:41 -0700 Message-ID: <4FFDE7D5.3080106@inktank.com> References: <4FFD847C.7070205@inktank.com> <4FFD8773.4020402@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-gh0-f174.google.com ([209.85.160.174]:44373 "EHLO mail-gh0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030191Ab2GKUxo (ORCPT ); Wed, 11 Jul 2012 16:53:44 -0400 Received: by ghrr11 with SMTP id r11so1718353ghr.19 for ; Wed, 11 Jul 2012 13:53:43 -0700 (PDT) In-Reply-To: <4FFD8773.4020402@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Alex Elder Cc: ceph-devel@vger.kernel.org Reviewed-by: Josh Durgin On 07/11/2012 07:02 AM, Alex Elder wrote: > There is no need to impose a small limit the length of the snapshot > name recorded for an rbd image in a struct rbd_dev. Remove the > limitation by allocating space for the snapshot name dynamically. > > Signed-off-by: Alex Elder > --- > drivers/block/rbd.c | 26 ++++++++++++++++---------- > 1 files changed, 16 insertions(+), 10 deletions(-) > > diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c > index 28afff9..90fb388 100644 > --- a/drivers/block/rbd.c > +++ b/drivers/block/rbd.c > @@ -171,7 +171,7 @@ struct rbd_device { > > /* protects updating the header */ > struct rw_semaphore header_rwsem; > - char snap_name[RBD_MAX_SNAP_NAME_LEN]; > + char *snap_name; > u64 snap_id; /* current snapshot id */ > int read_only; > > @@ -587,8 +587,6 @@ static int rbd_header_set_snap(struct rbd_device > *dev, u64 *size) > struct ceph_snap_context *snapc = header->snapc; > int ret = -ENOENT; > > - BUILD_BUG_ON(sizeof (dev->snap_name)< sizeof (RBD_SNAP_HEAD_NAME)); > - > down_write(&dev->header_rwsem); > > if (!memcmp(dev->snap_name, RBD_SNAP_HEAD_NAME, > @@ -2381,16 +2379,22 @@ static char *rbd_add_parse_args(struct > rbd_device *rbd_dev, > sprintf(rbd_dev->obj_md_name, "%s%s", rbd_dev->obj, RBD_SUFFIX); > > /* > - * The snapshot name is optional, but it's an error if it's > - * too long. If no snapshot is supplied, fill in the default. > + * The snapshot name is optional. If none is is supplied, > + * we use the default value. > */ > - len = copy_token(&buf, rbd_dev->snap_name, sizeof (rbd_dev->snap_name)); > - if (!len) > + rbd_dev->snap_name = dup_token(&buf,&len); > + if (!rbd_dev->snap_name) > + goto out_err; > + if (!len) { > + /* Replace the empty name with the default */ > + kfree(rbd_dev->snap_name); > + rbd_dev->snap_name > + = kmalloc(sizeof (RBD_SNAP_HEAD_NAME), GFP_KERNEL); > + if (!rbd_dev->snap_name) > + goto out_err; > + > memcpy(rbd_dev->snap_name, RBD_SNAP_HEAD_NAME, > sizeof (RBD_SNAP_HEAD_NAME)); > - else if (len>= sizeof (rbd_dev->snap_name)) { > - ret = -EINVAL; > - goto out_err; > } > > return pool_name; > @@ -2505,6 +2509,7 @@ err_out_client: > rbd_put_client(rbd_dev); > err_put_id: > if (pool_name) { > + kfree(rbd_dev->snap_name); > kfree(rbd_dev->obj_md_name); > kfree(rbd_dev->obj); > kfree(pool_name); > @@ -2557,6 +2562,7 @@ static void rbd_dev_release(struct device *dev) > unregister_blkdev(rbd_dev->major, rbd_dev->name); > > /* done with the id, and with the rbd_dev */ > + kfree(rbd_dev->snap_name); > kfree(rbd_dev->obj_md_name); > kfree(rbd_dev->obj); > rbd_id_put(rbd_dev);