On Thu, Aug 01, 2019 at 11:42:44AM -0700, Song Liu wrote:
> In previous patch, an application could put part of its text section in
> THP via madvise(). These THPs will be protected from writes when the
> application is still running (TXTBSY). However, after the application
> exits, the file is available for writes.
>
> This patch avoids writes to file THP by dropping page cache for the file
> when the file is open for write. A new counter nr_thps is added to struct
> address_space. In do_dentry_open(), if the file is open for write and
> nr_thps is non-zero, we drop page cache for the whole file.
>
> Cc: Johannes Weiner <[email protected]>
> Reported-by: kbuild test robot <[email protected]>
> Acked-by: Rik van Riel <[email protected]>
> Acked-by: Kirill A. Shutemov <[email protected]>
> Signed-off-by: Song Liu <[email protected]>
Acked-by: Johannes Weiner <[email protected]>