On Mon, Jan 17, 2022 at 12:44:33PM +0000, David Howells wrote:
> + if (ceph_caps_issued(ci) & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) {
> + folio = filemap_get_folio(inode->i_mapping, 0);
> + if (folio) {
> + if (folio_test_uptodate(folio)) {
> from_pagecache = true;
> - lock_page(page);
> + folio_lock(folio);
> } else {
> - put_page(page);
> - page = NULL;
> + folio_put(folio);
> + folio = NULL;
This all falls very much under "doing it the hard way", and quite
possibly under the "actively buggy with races" category.
read_mapping_folio() does what you want, as long as you pass 'filp'
as your 'void *data'. I should fix that type ...
