Re: Thoughts on mounting the rootfs from a udev rule

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Victor Lowther wrote:
It seems that there are two major use cases that make mounting the root
file system directly from a udev rule an inadvisable design decision:

The first is when your root filesystem does not reside on a block
device, as in the nfsroot case.  In this case, there is no backing
device for the filesystem for udev to detect, so we would still need a
non-udev method of mounting the root filesystem in order to handle any
case where there is no backing device for the root filesystem.

The second is when we are asked to resume from hibernate.  In this case,
we must not attempt to mount the root filesystem (or any other
filesystem, for that matter) until we have either attempted to resume
(and failed) or we have determined that resuming is impossible.  Udev
does not make any guarantees about the order in which devices are
discovered, which leads to all sorts of interesting potential failure
modes when you have either or both of resume handling and rootfs
handling in a udev rule.

Thoughts?

From experience with other software projects, having an event driven
system which asks 'something happened, what should I do' is preferrable
to having to write all the glue code yourself. And one of dracut's goals
is to get rid of as much shell code as possible no?

Question is: Are the described cases exlusive? I mean if udev does
something does it make thawing impossible? Of so, can we prevent it? Or
maybe just postpone starting udev or restart udev at a later point.

Regards,
Philippe



--
To unsubscribe from this list: send the line "unsubscribe initramfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Kernel]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux SCSI]

  Powered by Linux