Add __folio_clear_dirty_for_io() which takes in an arg for whether the
folio and wb stats should be updated as part of the call or not.
Signed-off-by: Joanne Koong <joannelkoong@xxxxxxxxx>
---
mm/page-writeback.c | 47 +++++++++++++++++++++++++++------------------
1 file changed, 28 insertions(+), 19 deletions(-)
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index a3805988f3ad..77a46bf8052f 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2927,21 +2927,7 @@ void __folio_cancel_dirty(struct folio *folio)
}
EXPORT_SYMBOL(__folio_cancel_dirty);
-/*
- * Clear a folio's dirty flag, while caring for dirty memory accounting.
- * Returns true if the folio was previously dirty.
- *
- * This is for preparing to put the folio under writeout. We leave
- * the folio tagged as dirty in the xarray so that a concurrent
- * write-for-sync can discover it via a PAGECACHE_TAG_DIRTY walk.
- * The ->writepage implementation will run either folio_start_writeback()
- * or folio_mark_dirty(), at which stage we bring the folio's dirty flag
- * and xarray dirty tag back into sync.
- *
- * This incoherency between the folio's dirty flag and xarray tag is
- * unfortunate, but it only exists while the folio is locked.
- */
-bool folio_clear_dirty_for_io(struct folio *folio)
+static bool __folio_clear_dirty_for_io(struct folio *folio, bool update_stats)
{
struct address_space *mapping = folio_mapping(folio);
bool ret = false;
@@ -2990,10 +2976,14 @@ bool folio_clear_dirty_for_io(struct folio *folio)
*/
wb = unlocked_inode_to_wb_begin(inode, &cookie);
if (folio_test_clear_dirty(folio)) {
- long nr = folio_nr_pages(folio);
- lruvec_stat_mod_folio(folio, NR_FILE_DIRTY, -nr);
- zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
- wb_stat_mod(wb, WB_RECLAIMABLE, -nr);
+ if (update_stats) {
+ long nr = folio_nr_pages(folio);
+ lruvec_stat_mod_folio(folio, NR_FILE_DIRTY,
+ -nr);
+ zone_stat_mod_folio(folio,
+ NR_ZONE_WRITE_PENDING, -nr);
+ wb_stat_mod(wb, WB_RECLAIMABLE, -nr);
+ }
ret = true;
}
unlocked_inode_to_wb_end(inode, &cookie);
@@ -3001,6 +2991,25 @@ bool folio_clear_dirty_for_io(struct folio *folio)
}
return folio_test_clear_dirty(folio);
}
+
+/*
+ * Clear a folio's dirty flag, while caring for dirty memory accounting.
+ * Returns true if the folio was previously dirty.
+ *
+ * This is for preparing to put the folio under writeout. We leave
+ * the folio tagged as dirty in the xarray so that a concurrent
+ * write-for-sync can discover it via a PAGECACHE_TAG_DIRTY walk.
+ * The ->writepage implementation will run either folio_start_writeback()
+ * or folio_mark_dirty(), at which stage we bring the folio's dirty flag
+ * and xarray dirty tag back into sync.
+ *
+ * This incoherency between the folio's dirty flag and xarray tag is
+ * unfortunate, but it only exists while the folio is locked.
+ */
+bool folio_clear_dirty_for_io(struct folio *folio)
+{
+ return __folio_clear_dirty_for_io(folio, true);
+}
EXPORT_SYMBOL(folio_clear_dirty_for_io);
static void wb_inode_writeback_start(struct bdi_writeback *wb)
--
2.47.3
