Re: [PATCH] Use of getblk differs between locations

[Mikulas Patocka]

On Thu, 13 Oct 2005, Jamie Lokier wrote:

> Mikulas Patocka wrote:
> > But discarding data sometimes on USB unplug is even worse than discarding
> > data always --- users will by experimenting learn that linux doesn't
> > discard write-cached data and reminds them to replug the device --- and
> > one day, randomly, they lose their data because of some memory management
> > condition...
>
> It should not happen provided the total amount of dirty data for
> detachable devices is restricted to allow enough room for opening a
> dialog.

That is possible ... you must also make sure that you do not hold an 
important semaphore while waiting for some removable device (auditing VFS 
for this will be a bit harder...)

Mikulas

> That's no different, in principle, than the restrictions that are used
> to ensure some types of kernel memory allocation always succeed.
>
> There's no exact calculation, just a notion of "this many megabytes
> should be enough for a dialog".
>
> -- Jamie
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