enum positive_aop_returns — aop return codes with specific semantics
enum positive_aop_returns {
AOP_WRITEPAGE_ACTIVATE,
AOP_TRUNCATED_PAGE
};
Informs the caller that page writeback has
completed, that the page is still locked, and
should be considered active. The VM uses this hint
to return the page to the active list -- it won't
be a candidate for writeback again in the near
future. Other callers must be careful to unlock
the page if they get this return. Returned by
writepage;
The AOP method that was handed a locked page has
unlocked it and the page might have been truncated.
The caller should back up to acquiring a new page and
trying again. The aop will be taking reasonable
precautions not to livelock. If the caller held a page
reference, it should drop it before retrying. Returned
by readpage, prepare_write, and commit_write.