filemap: add a per-mapping stable writes flag

[platform/kernel/linux-rpi.git] / include / linux / pagemap.h

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 351c3b7..8c9608b 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -204,6 +204,8 @@ enum mapping_flags {
        AS_NO_WRITEBACK_TAGS = 5,
        AS_LARGE_FOLIO_SUPPORT = 6,
        AS_RELEASE_ALWAYS,      /* Call ->release_folio(), even if no private data */
+       AS_STABLE_WRITES,       /* must wait for writeback before modifying
+                                  folio contents */
 };
 
 /**
@@ -289,6 +291,21 @@ static inline void mapping_clear_release_always(struct address_space *mapping)
        clear_bit(AS_RELEASE_ALWAYS, &mapping->flags);
 }
 
+static inline bool mapping_stable_writes(const struct address_space *mapping)
+{
+       return test_bit(AS_STABLE_WRITES, &mapping->flags);
+}
+
+static inline void mapping_set_stable_writes(struct address_space *mapping)
+{
+       set_bit(AS_STABLE_WRITES, &mapping->flags);
+}
+
+static inline void mapping_clear_stable_writes(struct address_space *mapping)
+{
+       clear_bit(AS_STABLE_WRITES, &mapping->flags);
+}
+
 static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
 {
        return mapping->gfp_mask;