On Thu, Mar 25, 2021 at 4:10 PM Joao Martins <joao.m.martins@xxxxxxxxxx> wrote: > > memory_failure_dev_pagemap() at the moment assumes base pages (e.g. > dax_lock_page()). For pagemap with compound pages fetch the > compound_head in case we are handling a tail page memory failure. > > Currently this is a nop, but in the advent of compound pages in > dev_pagemap it allows memory_failure_dev_pagemap() to keep working. > > Reported-by: Jane Chu <jane.chu@xxxxxxxxxx> > Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx> > --- > mm/memory-failure.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 24210c9bd843..94240d772623 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1318,6 +1318,8 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, > goto out; > } > > + page = compound_head(page); Unless / until we do compound pages for the filesystem-dax case, I would add a comment like: /* pages instantiated by device-dax (not filesystem-dax) may be compound pages */
