netfs, ceph: Revert "netfs: Remove deprecated use of PG_private_2 as a second writeback flag"

This reverts commit ae678317b95e760607c7b20b97c9cd4ca9ed6e1a.

Revert the patch that removes the deprecated use of PG_private_2 in
netfslib for the moment as Ceph is actually still using this to track
data copied to the cache.

Fixes: ae678317b95e ("netfs: Remove deprecated use of PG_private_2 as a second writeback flag")
Reported-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Xiubo Li <xiubli@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Matthew Wilcox <willy@infradead.org>
cc: ceph-devel@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
https: //lore.kernel.org/r/3575457.1722355300@warthog.procyon.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 18 insertions, 1 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 8c16bc5250ef..73b5a07bf94d 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -498,6 +498,11 @@ const struct netfs_request_ops ceph_netfs_ops = {
 };
 
 #ifdef CONFIG_CEPH_FSCACHE
+static void ceph_set_page_fscache(struct page *page)
+{
+	folio_start_private_2(page_folio(page)); /* [DEPRECATED] */
+}
+
 static void ceph_fscache_write_terminated(void *priv, ssize_t error, bool was_async)
 {
 	struct inode *inode = priv;
@@ -515,6 +520,10 @@ static void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, b
 			       ceph_fscache_write_terminated, inode, true, caching);
 }
 #else
+static inline void ceph_set_page_fscache(struct page *page)
+{
+}
+
 static inline void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, bool caching)
 {
 }
@@ -706,6 +715,8 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 		len = wlen;
 
 	set_page_writeback(page);
+	if (caching)
+		ceph_set_page_fscache(page);
 	ceph_fscache_write_to_cache(inode, page_off, len, caching);
 
 	if (IS_ENCRYPTED(inode)) {
@@ -789,6 +800,8 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc)
 		return AOP_WRITEPAGE_ACTIVATE;
 	}
 
+	folio_wait_private_2(page_folio(page)); /* [DEPRECATED] */
+
 	err = writepage_nounlock(page, wbc);
 	if (err == -ERESTARTSYS) {
 		/* direct memory reclaimer was killed by SIGKILL. return 0
@@ -1062,7 +1075,8 @@ get_more_pages:
 				unlock_page(page);
 				break;
 			}
-			if (PageWriteback(page)) {
+			if (PageWriteback(page) ||
+			    PagePrivate2(page) /* [DEPRECATED] */) {
 				if (wbc->sync_mode == WB_SYNC_NONE) {
 					doutc(cl, "%p under writeback\n", page);
 					unlock_page(page);
@@ -1070,6 +1084,7 @@ get_more_pages:
 				}
 				doutc(cl, "waiting on writeback %p\n", page);
 				wait_on_page_writeback(page);
+				folio_wait_private_2(page_folio(page)); /* [DEPRECATED] */
 			}
 
 			if (!clear_page_dirty_for_io(page)) {
@@ -1254,6 +1269,8 @@ new_request:
 			}
 
 			set_page_writeback(page);
+			if (caching)
+				ceph_set_page_fscache(page);
 			len += thp_size(page);
 		}
 		ceph_fscache_write_to_cache(inode, offset, len, caching);