ENUM POSITIVE_AOP_RE(9)                   The Linux VFS                   ENUM POSITIVE_AOP_RE(9)



NAME
       enum_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.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                   ENUM POSITIVE_AOP_RE(9)