f2fs: introduce f2fs_i_links_write with mark_inode_dirty_sync

This patch introduces f2fs_i_links_write() to call mark_inode_dirty_sync() when
changing inode->i_links.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index aa8cb45..02e0522 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -535,6 +535,7 @@
 	}
 
 	clear_nlink(inode);
+	mark_inode_dirty_sync(inode);
 
 	/* truncate all the data during iput */
 	iput(inode);
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index dc4beae..f8ca0f3 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -437,7 +437,7 @@
 		 */
 		if (inode->i_nlink == 0)
 			remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
-		inc_nlink(inode);
+		f2fs_i_links_write(inode, true);
 	}
 	return page;
 
@@ -456,7 +456,7 @@
 {
 	if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) {
 		if (S_ISDIR(inode->i_mode)) {
-			inc_nlink(dir);
+			f2fs_i_links_write(dir, true);
 			set_inode_flag(dir, FI_UPDATE_DIR);
 		}
 		clear_inode_flag(inode, FI_NEW_INODE);
@@ -675,7 +675,7 @@
 	down_write(&F2FS_I(inode)->i_sem);
 
 	if (S_ISDIR(inode->i_mode)) {
-		drop_nlink(dir);
+		f2fs_i_links_write(dir, false);
 		if (page)
 			update_inode(dir, page);
 		else
@@ -683,9 +683,9 @@
 	}
 	inode->i_ctime = CURRENT_TIME;
 
-	drop_nlink(inode);
+	f2fs_i_links_write(inode, false);
 	if (S_ISDIR(inode->i_mode)) {
-		drop_nlink(inode);
+		f2fs_i_links_write(inode, false);
 		f2fs_i_size_write(inode, 0);
 	}
 	up_write(&F2FS_I(inode)->i_sem);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 9536e9e..d98aaf3 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1557,6 +1557,15 @@
 	set_inode_flag(inode, FI_ACL_MODE);
 }
 
+static inline void f2fs_i_links_write(struct inode *inode, bool inc)
+{
+	if (inc)
+		inc_nlink(inode);
+	else
+		drop_nlink(inode);
+	mark_inode_dirty_sync(inode);
+}
+
 static inline void f2fs_i_blocks_write(struct inode *inode,
 					blkcnt_t diff, bool add)
 {
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index cbf61a5..af7c75a 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -349,9 +349,6 @@
 	f2fs_delete_entry(de, page, dir, inode);
 	f2fs_unlock_op(sbi);
 
-	/* In order to evict this inode, we set it dirty */
-	mark_inode_dirty(inode);
-
 	if (IS_DIRSYNC(dir))
 		f2fs_sync_fs(sbi->sb, 1);
 fail:
@@ -597,16 +594,16 @@
 	 * remove all unused data of tmpfile after abnormal power-off.
 	 */
 	add_orphan_inode(sbi, inode->i_ino);
-	f2fs_unlock_op(sbi);
-
 	alloc_nid_done(sbi, inode->i_ino);
 
 	if (whiteout) {
-		inode_dec_link_count(inode);
+		f2fs_i_links_write(inode, false);
 		*whiteout = inode;
 	} else {
 		d_tmpfile(dentry, inode);
 	}
+	/* link_count was changed by d_tmpfile as well. */
+	f2fs_unlock_op(sbi);
 	unlock_new_inode(inode);
 	return 0;
 
@@ -704,12 +701,10 @@
 		new_inode->i_ctime = CURRENT_TIME;
 		down_write(&F2FS_I(new_inode)->i_sem);
 		if (old_dir_entry)
-			drop_nlink(new_inode);
-		drop_nlink(new_inode);
+			f2fs_i_links_write(new_inode, false);
+		f2fs_i_links_write(new_inode, false);
 		up_write(&F2FS_I(new_inode)->i_sem);
 
-		mark_inode_dirty(new_inode);
-
 		if (!new_inode->i_nlink)
 			add_orphan_inode(sbi, new_inode->i_ino);
 		else
@@ -729,7 +724,7 @@
 		}
 
 		if (old_dir_entry) {
-			inc_nlink(new_dir);
+			f2fs_i_links_write(new_dir, true);
 			update_inode_page(new_dir);
 		}
 
@@ -784,8 +779,7 @@
 			f2fs_dentry_kunmap(old_inode, old_dir_page);
 			f2fs_put_page(old_dir_page, 0);
 		}
-		drop_nlink(old_dir);
-		mark_inode_dirty(old_dir);
+		f2fs_i_links_write(old_dir, false);
 		update_inode_page(old_dir);
 	}
 
@@ -913,10 +907,7 @@
 	old_dir->i_ctime = CURRENT_TIME;
 	if (old_nlink) {
 		down_write(&F2FS_I(old_dir)->i_sem);
-		if (old_nlink < 0)
-			drop_nlink(old_dir);
-		else
-			inc_nlink(old_dir);
+		f2fs_i_links_write(old_dir, old_nlink > 0);
 		up_write(&F2FS_I(old_dir)->i_sem);
 	}
 	mark_inode_dirty(old_dir);
@@ -934,10 +925,7 @@
 	new_dir->i_ctime = CURRENT_TIME;
 	if (new_nlink) {
 		down_write(&F2FS_I(new_dir)->i_sem);
-		if (new_nlink < 0)
-			drop_nlink(new_dir);
-		else
-			inc_nlink(new_dir);
+		f2fs_i_links_write(new_dir, new_nlink > 0);
 		up_write(&F2FS_I(new_dir)->i_sem);
 	}
 	mark_inode_dirty(new_dir);