diff mbox series

[2/2] mm/filemap: rewrite mapping_needs_writeback in less fancy manner

Message ID 156378817069.1087.1302816672037672488.stgit@buzz (mailing list archive)
State New, archived
Headers show
Series [1/2] mm/filemap: don't initiate writeback if mapping has no dirty pages | expand

Commit Message

Konstantin Khlebnikov July 22, 2019, 9:36 a.m. UTC 
This actually checks that writeback is needed or in progress.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
 mm/filemap.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/mm/filemap.c b/mm/filemap.c
index d9572593e5c7..29f503ffd70b 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -618,10 +618,13 @@  int filemap_fdatawait_keep_errors(struct address_space *mapping)
 }
 EXPORT_SYMBOL(filemap_fdatawait_keep_errors);
 
+/* Returns true if writeback might be needed or already in progress. */
 static bool mapping_needs_writeback(struct address_space *mapping)
 {
-	return (!dax_mapping(mapping) && mapping->nrpages) ||
-	    (dax_mapping(mapping) && mapping->nrexceptional);
+	if (dax_mapping(mapping))
+		return mapping->nrexceptional;
+
+	return mapping->nrpages;
 }
 
 int filemap_write_and_wait(struct address_space *mapping)