> -----Original Messages----- > From: wuzhouhui <wuzhouhui14@xxxxxxxxxxxxxxxx> > Sent Time: 2018-04-11 22:03:39 (Wednesday) > To: "Robert Wolfe" <robert.wolfe@xxxxxxxxxxxxxxx>, linux-newbie@xxxxxxxxxxxxxxx > Cc: > Subject: Re: FW: who create files under /dev/ > > I encountered an issue when developing md. When I using "mdadm -S > dev/md0" to destroy md device, the data structure (such as gendisk, > request_queue, kobject and mkdev_s) in kernel are destroyed but /dev/md0 > remained. So I want to know who is responsible to remove /dev/md0. Finally, I found the reason. Generally, the device file under /dev/ is created by kernel thread kdevtmpfs. When device driver request kdevtmpfs to delete a device file (by del_gendisk()), the kdevtmpfs will not delete it if this device file is not created by itself (see handle_remove() in linux/drivers/base/devtmpfs.c). In CentOS 7, I use old mdadm to create md device. In this version of mdadm, the codes that check udev availability have bugs in CentOS 7, this upstream commit fix it: 5ffdc2dd443d (Update test for "is udev active"). When mdadm found udev is not available, it will create /dev/md0 by itself, but it will not delete /dev/md0 when stop md device. Thank for everyone! > > On 04/11/2018 09:56 PM, Robert Wolfe wrote: > > From: Robert Wolfe [mailto:robert.wolfe@xxxxxxxxxxxxxxx] > > Sent: Wednesday, April 11, 2018 8:53 AM > > To: 'wuzhouhui' <wuzhouhui14@xxxxxxxxxxxxxxxx>; > > 'linux-newbie@xxxxxxxxxxxxxxx' <linux-newbie@xxxxxxxxxxxxxxx> > > Subject: RE: who create files under /dev/ > > > > These are usually created during the OS installation. The best way I would > > think to find this out is to do an ‘ls –lrt’ on the files in the /dev > > directory to see what user the directories were created by. Although, I am > > not quite sure why you would want to know this? > > > > From: linux-newbie-owner@xxxxxxxxxxxxxxx > > [mailto:linux-newbie-owner@xxxxxxxxxxxxxxx] On Behalf Of wuzhouhui > > Sent: Wednesday, April 11, 2018 4:48 AM > > To: linux-newbie@xxxxxxxxxxxxxxx > > Subject: Re: who create files under /dev/ > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-newbie" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.linux-learn.org/faqs ��.n��������+%������w��{.n�����{��w�n'��{ay� ʇڙ���f���h������_�(�階�ݢj"��������G����?���&���iO����v��m������)�^j����?}��
