ceph: drop usage of page_index

page_index is needed for mixed usage of page cache and swap cache, for
pure page cache usage, the caller can just use page->index instead.

It can't be a swap cache page here, so just drop it.

Link: https://lkml.kernel.org/r/20240521175854.96038-4-ryncsn@gmail.comSigned-off-by: Kairui Song <kasong@tencent.com>
Cc: Xiubo Li <xiubli@redhat.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Marc Dionne <marc.dionne@auristor.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/ceph/dir.c

@@ -141,7 +141,7 @@ __dcache_find_get_entry(struct dentry *parent, u64 idx,
 	if (ptr_pos >= i_size_read(dir))
 		return NULL;
 
-	if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
+	if (!cache_ctl->page || ptr_pgoff != cache_ctl->page->index) {
 		ceph_readdir_cache_release(cache_ctl);
 		cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
 		if (!cache_ctl->page) {

fs/ceph/inode.c

@@ -1863,7 +1863,7 @@ static int fill_readdir_cache(struct inode *dir, struct dentry *dn,
 	unsigned idx = ctl->index % nsize;
 	pgoff_t pgoff = ctl->index / nsize;
 
-	if (!ctl->page || pgoff != page_index(ctl->page)) {
+	if (!ctl->page || pgoff != ctl->page->index) {
 		ceph_readdir_cache_release(ctl);
 		if (idx == 0)
 			ctl->page = grab_cache_page(&dir->i_data, pgoff);