On Thu, 2019-06-20 at 13:53 -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_last(), if the file is open for write and > nr_thps > is non-zero, we drop page cache for the whole file. > > Signed-off-by: Song Liu <songliubraving@xxxxxx> Acked-by: Rik van Riel <riel@xxxxxxxxxxx> The comment for release_file_thp() is a little implementation specific, which is normally a bad thing (for code we expect to stick around for years), but probably the right thing for code that is just a step in the direction we want to go. Thank you for reworking these patches so quickly.
