Quote:
Originally Posted by eythian
At the risk of getting wildly off-topic and technical, this isn't the problem. The problem is that you would have two devices accessing one filesystem. Common operating systems use read/write caches on those filesystems, so what's on the disk doesn't necessarily match what's in memory.
Imagine two scenarios: device A has made changes to the FS in memory, but hasn't written them to the device when device B makes an update, then device A writes those cached versions that are now stale; and device A has a cached read of the FS that it's referring to to base changes on when device B writes to that area of disk behind its back. These would happen all the time, and would cause things to break in spectacular and interesting ways.
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I don't want to argue about semantics, but you
are talking about memory coherence here... as in 2 "devices" using some shared memory space. Your example is
Cache Coherence 101, which is a special case of memory coherence.
I
do understand what you're talking about, eythian. But my main point was, as you also mentioned, that it's nothing new and, is doable.
With regard to the Kobo though, our problem isn't as complex as your example. The USB connection only really needs access to the "user space" per say, which the device isn't going to be writing to at all. It could be done without changing filesystems or breaking the plug'n'play thumb-drive goodness.