f2fs: fix to set atomic write status more clear

1. After we start atomic write in a database file, before committing
all data, we'd better not set inode w/ vfs dirty status to avoid
redundant updates, instead, we only set inode w/ atomic dirty status.

2. After we commit all data, before committing metadata, we need to
clear atomic dirty status, and set vfs dirty status to allow vfs flush
dirty inode.

Cc: Daeho Jeong <daehojeong@google.com>
Reported-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Author: chaseyu

fs/f2fs/inode.c

@@ -34,7 +34,9 @@ void f2fs_mark_inode_dirty_sync(struct inode *inode, bool sync)
 	if (f2fs_inode_dirtied(inode, sync))
 		return;
 
-	if (f2fs_is_atomic_file(inode))
+	/* only atomic file w/ FI_ATOMIC_COMMITTED can be set vfs dirty */
+	if (f2fs_is_atomic_file(inode) &&
+			!is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
 		return;
 
 	mark_inode_dirty_sync(inode);

fs/f2fs/segment.c

@@ -376,7 +376,13 @@ static int __f2fs_commit_atomic_write(struct inode *inode)
 	} else {
 		sbi->committed_atomic_block += fi->atomic_write_cnt;
 		set_inode_flag(inode, FI_ATOMIC_COMMITTED);
+
+		/*
+		 * inode may has no FI_ATOMIC_DIRTIED flag due to no write
+		 * before commit.
+		 */
 		if (is_inode_flag_set(inode, FI_ATOMIC_DIRTIED)) {
+			/* clear atomic dirty status and set vfs dirty status */
 			clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
 			f2fs_mark_inode_dirty_sync(inode, true);
 		}

fs/f2fs/super.c

@@ -1532,7 +1532,9 @@ int f2fs_inode_dirtied(struct inode *inode, bool sync)
 	}
 	spin_unlock(&sbi->inode_lock[DIRTY_META]);
 
-	if (!ret && f2fs_is_atomic_file(inode))
+	/* if atomic write is not committed, set inode w/ atomic dirty */
+	if (!ret && f2fs_is_atomic_file(inode) &&
+			!is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
 		set_inode_flag(inode, FI_ATOMIC_DIRTIED);
 
 	return ret;