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 <hannes@xxxxxxxxxxx> > Reported-by: kbuild test robot <lkp@xxxxxxxxx> > Acked-by: Rik van Riel <riel@xxxxxxxxxxx> > Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > Signed-off-by: Song Liu <songliubraving@xxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
