ocfs2: clear dinode links count in case of error

In ocfs2_mknod(), if error occurs after dinode successfully allocated,
ocfs2 i_links_count will not be 0.

So even though we clear inode i_nlink before iput in error handling, it
still won't wipe inode since we'll refresh inode from dinode during inode
lock.  So just like clear inode i_nlink, we clear ocfs2 i_links_count as
well.  Also do the same change for ocfs2_symlink().

Link: https://lkml.kernel.org/r/20221017130227.234480-2-joseph.qi@linux.alibaba.com
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: Yan Wang <wangyan122@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: josephhz

fs/ocfs2/namei.c

@@ -232,6 +232,7 @@ static int ocfs2_mknod(struct user_namespace *mnt_userns,
 	handle_t *handle = NULL;
 	struct ocfs2_super *osb;
 	struct ocfs2_dinode *dirfe;
+	struct ocfs2_dinode *fe = NULL;
 	struct buffer_head *new_fe_bh = NULL;
 	struct inode *inode = NULL;
 	struct ocfs2_alloc_context *inode_ac = NULL;
@@ -382,6 +383,7 @@ static int ocfs2_mknod(struct user_namespace *mnt_userns,
 		goto leave;
 	}
 
+	fe = (struct ocfs2_dinode *) new_fe_bh->b_data;
 	if (S_ISDIR(mode)) {
 		status = ocfs2_fill_new_dir(osb, handle, dir, inode,
 					    new_fe_bh, data_ac, meta_ac);
@@ -454,8 +456,11 @@ static int ocfs2_mknod(struct user_namespace *mnt_userns,
 leave:
 	if (status < 0 && did_quota_inode)
 		dquot_free_inode(inode);
-	if (handle)
+	if (handle) {
+		if (status < 0 && fe)
+			ocfs2_set_links_count(fe, 0);
 		ocfs2_commit_trans(osb, handle);
+	}
 
 	ocfs2_inode_unlock(dir, 1);
 	if (did_block_signals)
@@ -2019,8 +2024,11 @@ static int ocfs2_symlink(struct user_namespace *mnt_userns,
 					ocfs2_clusters_to_bytes(osb->sb, 1));
 	if (status < 0 && did_quota_inode)
 		dquot_free_inode(inode);
-	if (handle)
+	if (handle) {
+		if (status < 0 && fe)
+			ocfs2_set_links_count(fe, 0);
 		ocfs2_commit_trans(osb, handle);
+	}
 
 	ocfs2_inode_unlock(dir, 1);
 	if (did_block_signals)