[PATCH v5 08/10] ceph: convert page cleanup loop in writepages_finish() to folios

[Tal Zussman]

Convert the page cleanup loop in writepages_finish() to work on folios.
Resolve the folio up front and unwrap any fscrypt bounce folio to its
page cache folio, storing the page cache page back into the array.

This removes a use of detach_page_private() and five calls to
compound_head() per page, while adding one back via page_folio().

While at it, remove the BUG_ON() in the num_pages loop, as it cannot be
triggered.

No functional change.

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

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 8e761144e8fb..f9741812e8a9 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -913,7 +913,6 @@ static void writepages_finish(struct ceph_osd_request *req)
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	struct ceph_client *cl = ceph_inode_to_client(inode);
 	struct ceph_osd_data *osd_data;
-	struct page *page;
 	int num_pages, total_pages = 0;
 	int i, j;
 	int rc = req->r_result;
@@ -960,35 +959,35 @@ static void writepages_finish(struct ceph_osd_request *req)
 					   (u64)osd_data->length);
 		total_pages += num_pages;
 		for (j = 0; j < num_pages; j++) {
-			page = osd_data->pages[j];
-			if (fscrypt_is_bounce_page(page)) {
-				page = fscrypt_pagecache_page(page);
+			struct folio *folio = page_folio(osd_data->pages[j]);
+
+			if (fscrypt_is_bounce_folio(folio)) {
+				folio = fscrypt_pagecache_folio(folio);
 				fscrypt_free_bounce_page(osd_data->pages[j]);
-				osd_data->pages[j] = page;
+				osd_data->pages[j] = &folio->page;
 			}
-			BUG_ON(!page);
-			WARN_ON(!PageUptodate(page));
+			WARN_ON(!folio_test_uptodate(folio));
 
 			if (atomic_long_dec_return(&fsc->writeback_count) <
 			     CONGESTION_OFF_THRESH(
 					fsc->mount_options->congestion_kb))
 				fsc->write_congested = false;
 
-			ceph_put_snap_context(detach_page_private(page));
-			end_page_writeback(page);
+			ceph_put_snap_context(folio_detach_private(folio));
+			folio_end_writeback(folio);
 
 			if (atomic64_dec_return(&mdsc->dirty_folios) <= 0) {
 				wake_up_all(&mdsc->flush_end_wq);
 				WARN_ON(atomic64_read(&mdsc->dirty_folios) < 0);
 			}
 
-			doutc(cl, "unlocking %p\n", page);
+			doutc(cl, "unlocking %p\n", folio);
 
 			if (remove_page)
 				generic_error_remove_folio(inode->i_mapping,
-							  page_folio(page));
+							  folio);
 
-			unlock_page(page);
+			folio_unlock(folio);
 		}
 		doutc(cl, "%llx.%llx wrote %llu bytes cleaned %d pages\n",
 		      ceph_vinop(inode), osd_data->length,

-- 
2.39.5