2013-09-03 18:16:26

by Milosz Tanski

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Subject: Question on vma_operations readpages and locking

Can anyone help me reason about the readpages() callback in vma_operations?

Do the pages that come in the argument list from readahead come
locked? The documentation in the kernel says nothing about locking on
the way in (Documentation/filesystems/Locking) unlike readpage. It
does say that the pages should be unlocked when the operation is done.

Should I assume that the readpages implementer needs to take care to
lock those pages her / his self?

I've been reading through the code for different filesystems to
understand what should happen but I'm not a 100% clear on it. Thanks
in advance,

- Milosz