ENUM POSITIVE_AOP_RE(9) The Linux VFS ENUM POSITIVE_AOP_RE(9)NAMEenum_positive_aop_returns - aop return codes with specific semantics
SYNOPSIS
enum positive_aop_returns {
AOP_WRITEPAGE_ACTIVATE,
AOP_TRUNCATED_PAGE
};
CONSTANTS
AOP_WRITEPAGE_ACTIVATE
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;
AOP_TRUNCATED_PAGE
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.
DESCRIPTION
address_space_operation functions return these large constants to
indicate special semantics to the caller. These are much larger than
the bytes in a page to allow for functions that return the number of
bytes operated on in a given page.
COPYRIGHTKernel Hackers Manual 2.6. November 2013 ENUM POSITIVE_AOP_RE(9)