[PATCH 2/6] ceph: use a folio in the inline read branch of ceph_filemap_fault()

[Tal Zussman]

Convert find_or_create_page() to __filemap_get_folio(), keeping the
existing GFP constraint. Saves three calls to compound_head().

The __ceph_do_getattr() locked page plumbing is converted separately,
so pass &folio->page for now.

Signed-off-by: Tal Zussman <tz2294@xxxxxxxxxxxx>
---
 fs/ceph/addr.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index c05bdf5d7273..988ead716991 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -2054,29 +2054,30 @@ static vm_fault_t ceph_filemap_fault(struct vm_fault *vmf)
 		ret = VM_FAULT_SIGBUS;
 	} else {
 		struct address_space *mapping = inode->i_mapping;
-		struct page *page;
+		struct folio *folio;
 
 		filemap_invalidate_lock_shared(mapping);
-		page = find_or_create_page(mapping, 0,
+		folio = __filemap_get_folio(mapping, 0,
+				FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
 				mapping_gfp_constraint(mapping, ~__GFP_FS));
-		if (!page) {
+		if (IS_ERR(folio)) {
 			ret = VM_FAULT_OOM;
 			goto out_inline;
 		}
-		err = __ceph_do_getattr(inode, page,
+		err = __ceph_do_getattr(inode, &folio->page,
 					 CEPH_STAT_CAP_INLINE_DATA, true);
 		if (err < 0 || off >= i_size_read(inode)) {
-			unlock_page(page);
-			put_page(page);
+			folio_unlock(folio);
+			folio_put(folio);
 			ret = vmf_error(err);
 			goto out_inline;
 		}
-		if (err < PAGE_SIZE)
-			zero_user_segment(page, err, PAGE_SIZE);
+		if (err < folio_size(folio))
+			folio_zero_segment(folio, err, folio_size(folio));
 		else
-			flush_dcache_page(page);
-		SetPageUptodate(page);
-		vmf->page = page;
+			flush_dcache_folio(folio);
+		folio_mark_uptodate(folio);
+		vmf->page = folio_page(folio, 0);
 		ret = VM_FAULT_MAJOR | VM_FAULT_LOCKED;
 out_inline:
 		filemap_invalidate_unlock_shared(mapping);

-- 
2.39.5