From: NU013809@NDSUVM1.BITNET (Greg Wettstein) Subject: Re: Linux file systems Date: 21 Jan 1993 13:30:06 GMT
I just wanted to offer a couple of comments. First a note of thanks to
Remy for supplying us with the original enhanced file system and for the
upcoming enhanced-enhanced :-) file system. I also applaud him for his
position on hoping that all filesystem maintainers/creators learn from
each others endeavors. Linux has profited much from previous associations
of this kind.
With the filesystems in such a state of flux I was wondering if anyone
has given some thought to incorporating a flag into their filesystems to
indicate the state of 'shutdown' of the filesystem. I suppose this would
be referred to as a filesystem 'dirty' flag for lack of a better word. This
may even already exist, although I have found no references to it.
The concept behind this is to provide some indication if the filesystem was
shut down in an orderly manner, ie sync'ed before the kernel dropped. Having
such a capability would allow the development of smart file system checkers
which could determine whether or not a filesystem had to be 'cleaned' upon
startup.
I would suspect that an ioctl or a kernel call would have to be implemented
which when called would mark all mounted filesystems that had this
attribute as clean. The reboot/halt/shutdown suites could be modified to
sync the kernel, then mark the filesystems and then either halt or reboot.
The first thing the configuration scripts would do would be to call the
file system checking programs which would in turn check the devices
status to determine whether or not there was the potential of a damaging
shutdown.
If I am overlooking something that already exists I would appreciate a
pointer on implementing this. I am re-writing our network's configuration
scripts and would like to include this functionality so that reboots will
be handled in an elegant fashion. Similar functionality can be kludged
via invisible files and the like but a kernel/filesystem based approach
has the flavor of a cleaner implementation. Comments, suggestions??
As always,
Dr. G.W. Wettstein
Oncology Research Division Computing Facility
Fargo Clinic / MeritCare
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