Cc: Christian Borntraeger <borntraeger@...>, Andrew Morton <akpm@...>, Nick Piggin <nickpiggin@...>, <linux-mm@...>, <linux-kernel@...>, Martin Schwidefsky <schwidefsky@...>, Theodore Ts'o <tytso@...>, <stable@...>
Ok. So the journal code here fundamentally depends on being able to
control the order of the writes, and something else being able to set
the buffer head dirty messes up that control.
It makes no sense to implement a ramdisk in a way that requires this.
Looks like it. There are even comments in jbd about the same class
of problems. Apparently dump and tune2fs on mounted filesystems have
triggered some of these issues. The practical question is any of this
trouble worth handling.
Thinking about it. I don't believe anyone has ever intentionally built
a filesystem tool that depends on being able to modify a file systems
metadata buffer heads while the filesystem is running, and doing that
would seem to be fragile as it would require a lot of cooperation
between the tool and the filesystem about how the filesystem uses and
implement things.
Now I guess I need to see how difficult a patch would be to give
filesystems magic inodes to keep their metadata buffer heads in.
Eric
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