Re: Upcoming: Notifications, FS notifications and fsinfo()

From: Karel Zak
Date: Wed Apr 01 2020 - 05:05:21 EST


On Tue, Mar 31, 2020 at 10:52:52PM +0100, David Howells wrote:
> Christian Brauner <christian.brauner@xxxxxxxxxx> wrote:
>
> > querying all properties of a mount atomically all-at-once,
>
> I don't actually offer that, per se.
>
> Having an atomic all-at-once query for a single mount is actually quite a
> burden on the system. There's potentially a lot of state involved, much of
> which you don't necessarily need.

If all means "all possible attributes" than it is unnecessary, for
example ext4 timestamps or volume uuid/label are rarely necessary.
We usually need together (as consistent set):

source
mountpoint
FS type
FS root (FSINFO_ATTR_MOUNT_PATH)
FS options (FSINFO_ATTR_CONFIGURATION)
VFS attributes
VFS propagation flags
mount ID
parent ID
devno (or maj:min)

Karel

--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com