f2fs: fix conditions to remain recovery information in f2fs_sync_file

This patch revisited whole the recovery information during the f2fs_sync_file.

In this patch, there are three information to make a decision.

a) IS_CHECKPOINTED,	/* is it checkpointed before? */
b) HAS_FSYNCED_INODE,	/* is the inode fsynced before? */
c) HAS_LAST_FSYNC,	/* has the latest node fsync mark? */

And, the scenarios for our rule are based on:

[Term] F: fsync_mark, D: dentry_mark

1. inode(x) | CP | inode(x) | dnode(F)
2. inode(x) | CP | inode(F) | dnode(F)
3. inode(x) | CP | dnode(F) | inode(x) | inode(F)
4. inode(x) | CP | dnode(F) | inode(F)
5. CP | inode(x) | dnode(F) | inode(DF)
6. CP | inode(DF) | dnode(F)
7. CP | dnode(F) | inode(DF)
8. CP | dnode(F) | inode(x) | inode(DF)

For example, #3, the three conditions should be changed as follows.

   inode(x) | CP | dnode(F) | inode(x) | inode(F)
a)    x       o      o          o          o
b)    x       x      x          x          o
c)    x       o      o          x          o

If f2fs_sync_file stops   ------^,
 it should write inode(F)    --------------^

So, the need_inode_block_update should return true, since
 c) get_nat_flag(e, HAS_LAST_FSYNC), is false.

For example, #8,
      CP | alloc | dnode(F) | inode(x) | inode(DF)
a)    o      x        x          x          x
b)    x               x          x          o
c)    o               o          x          o

If f2fs_sync_file stops   -------^,
 it should write inode(DF)    --------------^

Note that, the roll-forward policy should follow this rule, which means,
if there are any missing blocks, we doesn't need to recover that inode.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -1089,9 +1089,6 @@ static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
 	if (check_direct_IO(inode, rw, iter, offset))
 		return 0;
 
-	/* clear fsync mark to recover these blocks */
-	fsync_mark_clear(F2FS_I_SB(inode), inode->i_ino);
-
 	trace_f2fs_direct_IO_enter(inode, offset, count, rw);
 
 	err = blockdev_direct_IO(rw, iocb, inode, iter, offset, get_data_block);

fs/f2fs/f2fs.h

@@ -1224,9 +1224,9 @@ struct dnode_of_data;
 struct node_info;
 
 bool available_free_memory(struct f2fs_sb_info *, int);
-int is_checkpointed_node(struct f2fs_sb_info *, nid_t);
-bool fsync_mark_done(struct f2fs_sb_info *, nid_t);
-void fsync_mark_clear(struct f2fs_sb_info *, nid_t);
+bool is_checkpointed_node(struct f2fs_sb_info *, nid_t);
+bool has_fsynced_inode(struct f2fs_sb_info *, nid_t);
+bool need_inode_block_update(struct f2fs_sb_info *, nid_t);
 void get_node_info(struct f2fs_sb_info *, nid_t, struct node_info *);
 int get_dnode_of_data(struct dnode_of_data *, pgoff_t, int);
 int truncate_inode_blocks(struct inode *, pgoff_t);

fs/f2fs/file.c

@@ -207,15 +207,17 @@ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 			up_write(&fi->i_sem);
 		}
 	} else {
-		/* if there is no written node page, write its inode page */
-		while (!sync_node_pages(sbi, ino, &wbc)) {
-			if (fsync_mark_done(sbi, ino))
-				goto out;
+sync_nodes:
+		sync_node_pages(sbi, ino, &wbc);
+
+		if (need_inode_block_update(sbi, ino)) {
 			mark_inode_dirty_sync(inode);
 			ret = f2fs_write_inode(inode, NULL);
 			if (ret)
 				goto out;
+			goto sync_nodes;
 		}
+
 		ret = wait_on_node_pages_writeback(sbi, ino);
 		if (ret)
 			goto out;

fs/f2fs/node.c

@@ -123,44 +123,48 @@ static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
 	kmem_cache_free(nat_entry_slab, e);
 }
 
-int is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
+bool is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct nat_entry *e;
-	int is_cp = 1;
+	bool is_cp = true;
 
 	read_lock(&nm_i->nat_tree_lock);
 	e = __lookup_nat_cache(nm_i, nid);
 	if (e && !get_nat_flag(e, IS_CHECKPOINTED))
-		is_cp = 0;
+		is_cp = false;
 	read_unlock(&nm_i->nat_tree_lock);
 	return is_cp;
 }
 
-bool fsync_mark_done(struct f2fs_sb_info *sbi, nid_t nid)
+bool has_fsynced_inode(struct f2fs_sb_info *sbi, nid_t ino)
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct nat_entry *e;
-	bool fsync_done = false;
+	bool fsynced = false;
 
 	read_lock(&nm_i->nat_tree_lock);
-	e = __lookup_nat_cache(nm_i, nid);
-	if (e)
-		fsync_done = get_nat_flag(e, HAS_FSYNC_MARK);
+	e = __lookup_nat_cache(nm_i, ino);
+	if (e && get_nat_flag(e, HAS_FSYNCED_INODE))
+		fsynced = true;
 	read_unlock(&nm_i->nat_tree_lock);
-	return fsync_done;
+	return fsynced;
 }
 
-void fsync_mark_clear(struct f2fs_sb_info *sbi, nid_t nid)
+bool need_inode_block_update(struct f2fs_sb_info *sbi, nid_t ino)
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct nat_entry *e;
+	bool need_update = true;
 
-	write_lock(&nm_i->nat_tree_lock);
-	e = __lookup_nat_cache(nm_i, nid);
-	if (e)
-		set_nat_flag(e, HAS_FSYNC_MARK, false);
-	write_unlock(&nm_i->nat_tree_lock);
+	read_lock(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, ino);
+	if (e && get_nat_flag(e, HAS_LAST_FSYNC) &&
+			(get_nat_flag(e, IS_CHECKPOINTED) ||
+			 get_nat_flag(e, HAS_FSYNCED_INODE)))
+		need_update = false;
+	read_unlock(&nm_i->nat_tree_lock);
+	return need_update;
 }
 
 static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
@@ -176,7 +180,7 @@ static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
 	}
 	memset(new, 0, sizeof(struct nat_entry));
 	nat_set_nid(new, nid);
-	set_nat_flag(new, IS_CHECKPOINTED, true);
+	nat_reset_flag(new);
 	list_add_tail(&new->list, &nm_i->nat_entries);
 	nm_i->nat_cnt++;
 	return new;
@@ -244,12 +248,17 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
 
 	/* change address */
 	nat_set_blkaddr(e, new_blkaddr);
+	if (new_blkaddr == NEW_ADDR || new_blkaddr == NULL_ADDR)
+		set_nat_flag(e, IS_CHECKPOINTED, false);
 	__set_nat_cache_dirty(nm_i, e);
 
 	/* update fsync_mark if its inode nat entry is still alive */
 	e = __lookup_nat_cache(nm_i, ni->ino);
-	if (e)
-		set_nat_flag(e, HAS_FSYNC_MARK, fsync_done);
+	if (e) {
+		if (fsync_done && ni->nid == ni->ino)
+			set_nat_flag(e, HAS_FSYNCED_INODE, true);
+		set_nat_flag(e, HAS_LAST_FSYNC, fsync_done);
+	}
 	write_unlock(&nm_i->nat_tree_lock);
 }
 
@@ -1121,10 +1130,14 @@ int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
 
 			/* called by fsync() */
 			if (ino && IS_DNODE(page)) {
-				int mark = !is_checkpointed_node(sbi, ino);
 				set_fsync_mark(page, 1);
-				if (IS_INODE(page))
-					set_dentry_mark(page, mark);
+				if (IS_INODE(page)) {
+					if (!is_checkpointed_node(sbi, ino) &&
+						!has_fsynced_inode(sbi, ino))
+						set_dentry_mark(page, 1);
+					else
+						set_dentry_mark(page, 0);
+				}
 				nwritten++;
 			} else {
 				set_fsync_mark(page, 0);
@@ -1912,6 +1925,7 @@ void flush_nat_entries(struct f2fs_sb_info *sbi)
 				write_unlock(&nm_i->nat_tree_lock);
 			} else {
 				write_lock(&nm_i->nat_tree_lock);
+				nat_reset_flag(ne);
 				__clear_nat_cache_dirty(nm_i, ne);
 				write_unlock(&nm_i->nat_tree_lock);
 			}

fs/f2fs/node.h

@@ -41,7 +41,8 @@ struct node_info {
 
 enum {
 	IS_CHECKPOINTED,	/* is it checkpointed before? */
-	HAS_FSYNC_MARK,		/* has the latest node fsync mark? */
+	HAS_FSYNCED_INODE,	/* is the inode fsynced before? */
+	HAS_LAST_FSYNC,		/* has the latest node fsync mark? */
 };
 
 struct nat_entry {
@@ -60,15 +61,9 @@ struct nat_entry {
 #define nat_set_version(nat, v)		(nat->ni.version = v)
 
 #define __set_nat_cache_dirty(nm_i, ne)					\
-	do {								\
-		set_nat_flag(ne, IS_CHECKPOINTED, false);		\
-		list_move_tail(&ne->list, &nm_i->dirty_nat_entries);	\
-	} while (0)
+		list_move_tail(&ne->list, &nm_i->dirty_nat_entries);
 #define __clear_nat_cache_dirty(nm_i, ne)				\
-	do {								\
-		set_nat_flag(ne, IS_CHECKPOINTED, true);		\
-		list_move_tail(&ne->list, &nm_i->nat_entries);		\
-	} while (0)
+		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,
@@ -87,6 +82,14 @@ static inline bool get_nat_flag(struct nat_entry *ne, unsigned int type)
 	return ne->flag & mask;
 }
 
+static inline void nat_reset_flag(struct nat_entry *ne)
+{
+	/* these states can be set only after checkpoint was done */
+	set_nat_flag(ne, IS_CHECKPOINTED, true);
+	set_nat_flag(ne, HAS_FSYNCED_INODE, false);
+	set_nat_flag(ne, HAS_LAST_FSYNC, true);
+}
+
 static inline void node_info_from_raw_nat(struct node_info *ni,
 						struct f2fs_nat_entry *raw_ne)
 {