1 files changed, 26 insertions, 10 deletions

diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 3298c29b5548..6d49319c82c6 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -10,8 +10,11 @@
 #include "internal.h"
 
 /*
- * Unlock the folios in a read operation.  We need to set PG_fscache on any
+ * Unlock the folios in a read operation.  We need to set PG_writeback on any
  * folios we're going to write back before we unlock them.
+ *
+ * Note that if the deprecated NETFS_RREQ_USE_PGPRIV2 is set then we use
+ * PG_private_2 and do a direct write to the cache from here instead.
  */
 void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
 {
@@ -48,14 +51,14 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
 	xas_for_each(&xas, folio, last_page) {
 		loff_t pg_end;
 		bool pg_failed = false;
-		bool folio_started;
+		bool wback_to_cache = false;
+		bool folio_started = false;
 
 		if (xas_retry(&xas, folio))
 			continue;
 
 		pg_end = folio_pos(folio) + folio_size(folio) - 1;
 
-		folio_started = false;
 		for (;;) {
 			loff_t sreq_end;
 
@@ -63,10 +66,16 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
 				pg_failed = true;
 				break;
 			}
-			if (!folio_started && test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {
-				trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache);
-				folio_start_fscache(folio);
-				folio_started = true;
+			if (test_bit(NETFS_RREQ_USE_PGPRIV2, &rreq->flags)) {
+				if (!folio_started && test_bit(NETFS_SREQ_COPY_TO_CACHE,
+							       &subreq->flags)) {
+					trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache);
+					folio_start_fscache(folio);
+					folio_started = true;
+				}
+			} else {
+				wback_to_cache |=
+					test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
 			}
 			pg_failed |= subreq_failed;
 			sreq_end = subreq->start + subreq->len - 1;
@@ -98,6 +107,11 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
 				kfree(finfo);
 			}
 			folio_mark_uptodate(folio);
+			if (wback_to_cache && !WARN_ON_ONCE(folio_get_private(folio) != NULL)) {
+				trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache);
+				folio_attach_private(folio, NETFS_FOLIO_COPY_TO_CACHE);
+				filemap_dirty_folio(folio->mapping, folio);
+			}
 		}
 
 		if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) {
@@ -491,9 +505,11 @@ retry:
 	netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
 
 have_folio:
-	ret = folio_wait_fscache_killable(folio);
-	if (ret < 0)
-		goto error;
+	if (test_bit(NETFS_ICTX_USE_PGPRIV2, &ctx->flags)) {
+		ret = folio_wait_fscache_killable(folio);
+		if (ret < 0)
+			goto error;
+	}
 have_folio_no_wait:
 	*_folio = folio;
 	_leave(" = 0");