From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: /sys/block/md126 still exists even after stopping the array Date: Mon, 29 Sep 2014 14:47:07 +1000 Message-ID: <20140929144707.39fc5ec0@notabene.brown> References: <53A99B76.3020603@gmail.com> <20140625110348.48ab2d7a@notabene.brown> <54243ED7.6090904@gmail.com> <20140926103348.5f5ea568@notabene.brown> <54253E9F.4070505@gmail.com> <20140926204445.1ec830b9@notabene.brown> <54255A30.9010406@gmail.com> <54256100.3090507@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/stDl8EyCgutIBNCEQsVBu0Z"; protocol="application/pgp-signature" Return-path: In-Reply-To: <54256100.3090507@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: Francis Moreau Cc: linux-raid , sebastian.riemer@profitbricks.com List-Id: linux-raid.ids --Sig_/stDl8EyCgutIBNCEQsVBu0Z Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Fri, 26 Sep 2014 14:50:08 +0200 Francis Moreau wrote: > On 09/26/2014 02:21 PM, Francis Moreau wrote: > [...] >=20 > >=20 > >>>> mdadm --stop --scan <<< > >=20 > > [ 89.975162] md_open(): md125 opened by mdadm [930] > > [ 89.975305] md_release(): md125 released by mdadm [930] > > [ 89.977434] md_open(): md125 opened by mdadm [932] > > [ 89.978813] md_open(): md125 opened by mdadm [930] > > [ 89.979365] md_release(): md125 released by mdadm [932] > > [ 89.979693] md_open(): md125 opened by systemd-udevd [931] > > [ 89.985790] md_release(): md125 released by systemd-udevd [931] > > [ 90.179911] md_release(): md125 released by mdadm [930] > > [ 90.180168] md_open(): md127 opened by mdadm [459] > > [ 90.180187] md_release(): md127 released by mdadm [459] > > [ 90.180199] md_open(): md126 opened by mdadm [459] > > [ 90.180205] md_release(): md126 released by mdadm [459] > > [ 90.180556] md_open(): md126 opened by mdadm [930] > > [ 90.180653] md_release(): md126 released by mdadm [930] > > [ 90.180690] md_open(): md126 opened by mdadm [930] > > [ 90.180758] md_open(): mdX opened by mdadm [459] >=20 > What is this 'mdX' device that mdadm operates on ? >=20 > It also doesn't have a counterpart release() call. 'mdX' is the name used if mddev->gendisk is NULL. In that case, md_open() will return an error (ERESTARTSYS). As the 'open' failed, we wouldn't expect a matching close/release. NeilBrown >=20 >=20 > > [ 90.180995] md_open(): md125 opened by mdadm [459] > > [ 90.181056] md_release(): md125 released by mdadm [459] > > [ 90.182717] md_open(): md127 opened by mdadm [459] > > [ 90.182725] md_release(): md127 released by mdadm [459] > > [ 90.182732] md_open(): md126 opened by mdadm [459] > > [ 90.182761] md_release(): md126 released by mdadm [459] > > [ 90.182770] md_open(): md125 opened by mdadm [459] > > [ 90.182775] md_release(): md125 released by mdadm [459] > > [ 90.182940] md_release(): md126 released by mdadm [930] > > [ 90.183167] md_open(): md127 opened by mdadm [930] > > [ 90.183257] md_release(): md127 released by mdadm [930] > > [ 90.183288] md_open(): md127 opened by mdadm [930] > > [ 90.183461] md_open(): md127 opened by mdadm [459] > > [ 90.183488] md_release(): md127 released by mdadm [459] > > [ 90.183499] md_open(): md125 opened by mdadm [459] > > [ 90.183505] md_release(): md125 released by mdadm [459] > > [ 90.183686] md_release(): md127 released by mdadm [930] > >=20 > >=20 > >> Probably there is a 'change' event happening just before the 'remove' = event, > >> and udev runs "mdadm" on the 'change' event, and that ends up happenin= g after > >> the device has been removed. > >> > >> Is this really a problem? Can't you just ignore it and pretend it isn= 't > >> there? > >=20 > > Well, if you list the block devices that the kernel detected in order to > > operate on them, it could. I don't know exactly what would be the result > > to use it but it could confuse some tools. > >=20 > > Is there a way to check that the 'ghost' device has been removed by > > poking sysfs ? > >=20 > > Thanks > >=20 >=20 > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html --Sig_/stDl8EyCgutIBNCEQsVBu0Z Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIVAwUBVCjkSznsnt1WYoG5AQL+sxAAhU/BF27meg+y8HwHPNbok6d/2IGH0h3I kleBIfgmhyHWJINJgIo/f3xTQhS04IgtkXMN/PTJPYcAo9do+PNI4jrmIjDKYaIz t6+gfzQL0xADS2R0IeFR8X7v90dZxi/5qtxxMBtsgh8cohSVrcYRpC3b1TarzVyy 0IM/Nbx0weddL1joIjlbG6oYqyraNKMfOuDk/yF4kCxRQyFDK7Bf0+xV9RxIZkhg 6XAWjumIqb/p6RyhaZnO3fgX8lSNFqunMllge1X/VYUXx944lej3tGB/7k+XsFdv oBa4awrUWsmdvRg8aZp/Myvw6HYhVbMRYMQS61BwD0pWzHtkTo5cNikmtEvRRUL+ dyp9yYXTKyYNRX5EoNBstA4s5JGDazrIDAaxXmLx/70YpG8/3XDW0p2PeGRLsK7j 88XrqBvjdQN+GiiD9+geRvBsI/oaMh3ElMnIqm24a18iOeBs8LDUafS59r0FH381 gXgBLAswpTvFXkhLl4iVmAtx26jFUT+RkqBchuFmYW5qT0idZuokC0hw66zxPeXY fIh5xU2paACZ4SYnapub5D/x1pdgJB8tCcvkXoGxMgw8Ni3VK+NJkNfMy7jkgIp3 3mJfq+S9aMyNcdIoi8KhQFAo7wGT+QQvwuzIflzdYYuAucyuLst40Of4qm+0QF38 Qp215KcVCF8= =DO1h -----END PGP SIGNATURE----- --Sig_/stDl8EyCgutIBNCEQsVBu0Z--