On Wed, Feb 12, 2020 at 11:13:56AM +0100, Jan Kara wrote:
> When handling a page fault, we drop mmap_sem to start async readahead so
> that we don't block on IO submission with mmap_sem held. However
> there's no point to drop mmap_sem in case readahead is disabled. Handle
> that case to avoid pointless dropping of mmap_sem and retrying the
> fault. This was actually reported to block mlockall(MCL_CURRENT)
> indefinitely.
>
> Fixes: 6b4c9f446981 ("filemap: drop the mmap_sem for all blocking operations")
> Reported-by: Minchan Kim <minchan@xxxxxxxxxx>
> Reported-by: Robert Stupp <snazy@xxxxxx>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
Reveiewed-by: Minchan Kim <minchan@xxxxxxxxxx>
