From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Rajnoha Subject: Re: [mdadm PATCH] Create: tell udev md device is not ready when first created. Date: Wed, 3 May 2017 16:32:14 +0200 Message-ID: <2fb51c71-4398-e206-4a94-5dcd13d78603@redhat.com> References: <149265560315.31004.3851231165281498425.stgit@noble> <149265600601.31004.323865505557190368.stgit@noble> <87mvbasqx6.fsf@notabene.neil.brown.name> <40a5fbff-9eef-07b3-fe1b-fb9a888cfb8b@redhat.com> <87h919ruj5.fsf@notabene.neil.brown.name> <01f50f57-c55e-e87f-b5a1-ded4647368b2@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <01f50f57-c55e-e87f-b5a1-ded4647368b2@gmail.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Jes Sorensen , NeilBrown Cc: linux-raid@vger.kernel.org, dm-devel@redhat.com List-Id: linux-raid.ids On 05/02/2017 03:42 PM, Jes Sorensen wrote: > On 04/28/2017 01:05 AM, NeilBrown wrote: >> >> When an array is created the content is not initialized, >> so it could have remnants of an old filesystem or md array >> etc on it. >> udev will see this and might try to activate it, which is almost >> certainly not what is wanted. >> >> So create a mechanism for mdadm to communicate with udev to tell >> it that the device isn't ready. This mechanism is the existance >> of a file /run/mdadm/created-mdXXX where mdXXX is the md device name. >> >> When creating an array, mdadm will create the file. >> A new udev rule file, 01-md-raid-creating.rules, will detect the >> precense of thst file and set ENV{SYSTEMD_READY}="0". >> This is fairly uniformly used to suppress actions based on the >> contents of the device. >> >> Signed-off-by: NeilBrown >> --- >> Assemble.c | 2 +- >> Build.c | 2 +- >> Create.c | 9 +++++++- >> Incremental.c | 4 ++-- >> Makefile | 4 ++-- >> lib.c | 29 +++++++++++++++++++++++++ >> mdadm.h | 4 +++- >> mdopen.c | 52 >> ++++++++++++++++++++++++++++----------------- >> udev-md-raid-creating.rules | 7 ++++++ >> 9 files changed, 86 insertions(+), 27 deletions(-) >> create mode 100644 udev-md-raid-creating.rules > > Applied! > How is this solving the problem then? The patch is flagging a device as not ready, then clearing the flag after some time. Where does the wiping happen actually? -- Peter