f2fs: refactor flush_nat_entries to remove costly reorganizing ops

Previously, f2fs tries to reorganize the dirty nat entries into multiple sets
according to its nid ranges. This can improve the flushing nat pages, however,
if there are a lot of cached nat entries, it becomes a bottleneck.

This patch introduces a new set management flow by removing dirty nat list and
adding a series of set operations when the nat entry becomes dirty.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 3 insertions, 6 deletions

diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index b8ba63c..bd826d9 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -43,6 +43,7 @@ enum {
 	IS_CHECKPOINTED,	/* is it checkpointed before? */
 	HAS_FSYNCED_INODE,	/* is the inode fsynced before? */
 	HAS_LAST_FSYNC,		/* has the latest node fsync mark? */
+	IS_DIRTY,		/* this nat entry is dirty? */
 };
 
 struct nat_entry {
@@ -60,10 +61,6 @@ struct nat_entry {
 #define nat_get_version(nat)		(nat->ni.version)
 #define nat_set_version(nat, v)		(nat->ni.version = v)
 
-#define __set_nat_cache_dirty(nm_i, ne)					\
-		list_move_tail(&ne->list, &nm_i->dirty_nat_entries);
-#define __clear_nat_cache_dirty(nm_i, ne)				\
-		list_move_tail(&ne->list, &nm_i->nat_entries);
 #define inc_node_version(version)	(++version)
 
 static inline void set_nat_flag(struct nat_entry *ne,
@@ -113,9 +110,9 @@ enum mem_type {
 };
 
 struct nat_entry_set {
-	struct list_head set_list;	/* link with all nat sets */
+	struct list_head set_list;	/* link with other nat sets */
 	struct list_head entry_list;	/* link with dirty nat entries */
-	nid_t start_nid;		/* start nid of nats in set */
+	nid_t set;			/* set number*/
 	unsigned int entry_cnt;		/* the # of nat entries in set */
 };