Query on mm/folio-compat: pagecache_get_page

From: Deepak R Varma
Date: Tue Feb 14 2023 - 13:23:50 EST


Hello,
Could someone comment if it is safe to access the page member variable as
written on line #100 when folio is NULL as returned from the
__filemap_get_folio() function call? Is this kind of intentional page-fault
trigger for the system to handle a new/fresh page allocation?

2 folio = __filemap_get_folio(mapping, index, fgp_flags, gfp);
1 if (!folio || xa_is_value(folio))
100 return &folio->page;
1 return folio_file_page(folio, index);

The code is part of commit ID c5255b421fd04

Thank you,
./drv