From: Karel Zak <kzak@redhat.com>
To: Qu Wenruo <quwenruo@cn.fujitsu.com>
Cc: util-linux@vger.kernel.org
Subject: Re: libblkid: Idea to force given cached entry to be invalidated?
Date: Fri, 18 Apr 2014 13:02:44 +0200 [thread overview]
Message-ID: <20140418110244.GL5786@x2.net.home> (raw)
In-Reply-To: <534F90D2.1030807@cn.fujitsu.com>
On Thu, Apr 17, 2014 at 04:29:06PM +0800, Qu Wenruo wrote:
> >>So if someone (maybe insane) use mknod to create as block device file and
> >>use 'btrfs dev del' on the newly created
> >>block device file, libblkid will still be unable to detect the change since
> >>the ctime/mtime of block device file in /dev/
> >>does not change.
> >Not sure if I understand, it would be nice to have complete example.
> >
> > Karel
> >
> Sorry for my poor English.
> Use /dev/sda6(major 8, minor 6) as an example.
> ------
> # stat /dev/sda6
> File: '/dev/sda6'
> Size: 0 Blocks: 0 IO Block: 4096 block special file
> Device: 5h/5d Inode: 7289 Links: 1 Device type: 8,6
> Access: (0660/brw-rw----) Uid: ( 0/ root) Gid: ( 6/ disk)
> Access: 2014-04-17 12:30:08.981732698 +0800
> Modify: 2014-04-17 12:30:08.981732698 +0800
> Change: 2014-04-17 12:30:08.981732698 +0800
> ^^^^^^^^^^^^^^^^^
> Birth: -
> # mknod sda6 b 8 6
> # mkfs.ext4 ./sda6 <<< Not /dev/sda6
Ah... it's too crazy to support this scenario :-)
Karel
--
Karel Zak <kzak@redhat.com>
http://karelzak.blogspot.com
prev parent reply other threads:[~2014-04-18 11:02 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-15 2:15 libblkid: Idea to force given cached entry to be invalidated? Qu Wenruo
2014-04-15 4:27 ` Theodore Ts'o
2014-04-15 4:52 ` Qu Wenruo
2014-04-15 11:21 ` Karel Zak
2014-04-16 0:53 ` Qu Wenruo
2014-04-16 9:03 ` Karel Zak
2014-04-17 1:17 ` Qu Wenruo
2014-04-17 8:21 ` Karel Zak
2014-04-17 8:29 ` Qu Wenruo
2014-04-18 11:02 ` Karel Zak [this message]
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