From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH 1/2] dm: update table type check for dax Date: Tue, 28 Jun 2016 16:07:15 -0400 Message-ID: <20160628200714.GC8300@redhat.com> References: <1467142636-21094-1-git-send-email-toshi.kani@hpe.com> <1467142636-21094-2-git-send-email-toshi.kani@hpe.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1467142636-21094-2-git-send-email-toshi.kani-ZPxbGqLxI0U@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Toshi Kani Cc: linux-nvdimm-y27Ovi1pjclAfugRpC6u6w@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-raid-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, agk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org List-Id: linux-raid.ids On Tue, Jun 28 2016 at 3:37pm -0400, Toshi Kani wrote: > Allow table type DM_TYPE_BIO_BASED to extend with > DM_TYPE_DAX_BIO_BASED since DM_TYPE_DAX_BIO_BASED > supports bio-based requests. > > Signed-off-by: Toshi Kani > Cc: Mike Snitzer > Cc: Alasdair Kergon > Cc: Dan Williams > --- > drivers/md/dm-ioctl.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c > index b59e3459..0f32791 100644 > --- a/drivers/md/dm-ioctl.c > +++ b/drivers/md/dm-ioctl.c > @@ -1267,6 +1267,15 @@ static int populate_table(struct dm_table *table, > return dm_table_complete(table); > } > > +static bool is_valid_type(unsigned cur, unsigned new) > +{ > + if (cur == new || > + (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED)) > + return true; > + > + return false; > +} > + > static int table_load(struct dm_ioctl *param, size_t param_size) > { > int r; > @@ -1309,7 +1318,7 @@ static int table_load(struct dm_ioctl *param, size_t param_size) > DMWARN("unable to set up device queue for new table."); > goto err_unlock_md_type; > } > - } else if (dm_get_md_type(md) != dm_table_get_type(t)) { > + } else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) { > DMWARN("can't change device type after initial table load."); > r = -EINVAL; > goto err_unlock_md_type; > You said in the 0th header: "Patch 1 solves an error when lvremove is made to a snapshot device." I'm not seeing why this patch 1 fixes anything specific to snapshot device removal (but I can see why patch 2 makes snapshot creation "work"). I'll apply your 2nd patch and see if I can see what you mean. I actually see this error, without either of your 2 proposed patches applied, when I try to create a snapshot of a DAX capable LV: # lvcreate -s -n snap -L 100M pmem/lv device-mapper: reload ioctl on (253:7) failed: Invalid argument Failed to lock logical volume pmem/lv. Aborting. Manual intervention required. Jun 28 15:57:28 rhel-storage-02 kernel: device-mapper: ioctl: can't change device type after initial table load.