nilfs2: decrement inodes count only if raw inode was successfully deleted

This fixes the issue that inodes count will not add up after removal
of raw inodes fails.  Hence, this prevents possible under flow of the
inodes count.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/inode.c

@@ -707,6 +707,7 @@ void nilfs_evict_inode(struct inode *inode)
 	struct nilfs_transaction_info ti;
 	struct super_block *sb = inode->i_sb;
 	struct nilfs_inode_info *ii = NILFS_I(inode);
+	int ret;
 
 	if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 		if (inode->i_data.nrpages)
@@ -725,8 +726,9 @@ void nilfs_evict_inode(struct inode *inode)
 	nilfs_mark_inode_dirty(inode);
 	end_writeback(inode);
 
-	nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
-	atomic_dec(&ii->i_root->inodes_count);
+	ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
+	if (!ret)
+		atomic_dec(&ii->i_root->inodes_count);
 
 	nilfs_clear_inode(inode);