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Re: help



Hi,

On Thu, 2003-03-06 at 14:48, ravindra singh mahala wrote:

> i'm implementing journaling support in vfat,
> basically i'want to know that how kernel come to
> know about unclean unmount at the time of reboot,
> if i'm not wrong it must be checking this before
> mounting a filesystem.

For ext2/3, the kernel sets a flag in the superblock on disk when the
filesystem is mounted, and clears it on unmount.  (On ext2, it's a "this
filesystem is unclean" flag; on ext3, it's a different "this filesystem
needs journal recovery" flag, but the mechanism is basically the same.)

So, if you see the flag already set at boot time or mount time, you know
that the fs was not cleanly unmounted.

You'll need a similar on-disk mark for vfat, but I've no idea where
would be the right place to record that info on a vfat partition.

--Stephen






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