From 7e9a7ceaa9d3851963f92f99ce012f7cd99e742b Mon Sep 17 00:00:00 2001
From: Zhihao Cheng <chengzhihao1@huawei.com>
Date: Mon, 11 Nov 2024 17:08:00 +0800
Subject: fsck.ubifs: Move common functions and data structures into
 fsck.ubifs.c

This is a preparation for adding TNC checking support. Following data
structures and functions are moved into fsck.ubifs.c:
 1. Move 'scanned_files' and 'used_lebs' from rebuild module, make them
    resuable for non-rebuild_fs modes.
 2. Move function 'handle_error' from load_fs.c, it could be reused in
    other steps.
 3. Add new function ubifs_tnc_remove_node in libubifs, which could
    remove index entry for a node by given position.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---
 ubifs-utils/libubifs/tnc.c   | 64 ++++++++++++++++++++++++++++++++++++++++++++
 ubifs-utils/libubifs/ubifs.h |  2 ++
 2 files changed, 66 insertions(+)

(limited to 'ubifs-utils/libubifs')

diff --git a/ubifs-utils/libubifs/tnc.c b/ubifs-utils/libubifs/tnc.c
index cd1013d..9277062 100644
--- a/ubifs-utils/libubifs/tnc.c
+++ b/ubifs-utils/libubifs/tnc.c
@@ -2456,6 +2456,70 @@ int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
 	return ubifs_tnc_remove_range(c, &key1, &key2);
 }
 
+/**
+ * ubifs_tnc_remove_node - remove an index entry of a node by given position.
+ * @c: UBIFS file-system description object
+ * @key: key of node
+ * @lnum: LEB number of node
+ * @offs: node offset
+ *
+ * Returns %0 on success or negative error code on failure.
+ */
+int ubifs_tnc_remove_node(struct ubifs_info *c, const union ubifs_key *key,
+			  int lnum, int offs)
+{
+	int found, n, err = 0;
+	struct ubifs_znode *znode;
+
+	mutex_lock(&c->tnc_mutex);
+	dbg_tnck(key, "pos %d:%d, key ", lnum, offs);
+	found = lookup_level0_dirty(c, key, &znode, &n);
+	if (found < 0) {
+		err = found;
+		goto out_unlock;
+	}
+	if (found == 1) {
+		struct ubifs_zbranch *zbr = &znode->zbranch[n];
+
+		if (zbr->lnum == lnum && zbr->offs == offs) {
+			err = tnc_delete(c, znode, n);
+		} else if (is_hash_key(c, key)) {
+			found = resolve_collision_directly(c, key, &znode, &n,
+							   lnum, offs);
+			if (found < 0) {
+				err = found;
+				goto out_unlock;
+			}
+
+			if (found) {
+				/* Ensure the znode is dirtied */
+				if (znode->cnext || !ubifs_zn_dirty(znode)) {
+					znode = dirty_cow_bottom_up(c, znode);
+					if (IS_ERR(znode)) {
+						err = PTR_ERR(znode);
+						goto out_unlock;
+					}
+				}
+				err = tnc_delete(c, znode, n);
+			} else {
+				goto not_found;
+			}
+		} else {
+			goto not_found;
+		}
+	} else {
+not_found:
+		/* Impossible, the node has been found before being deleted. */
+		ubifs_assert(c, 0);
+	}
+	if (!err)
+		err = dbg_check_tnc(c, 0);
+
+out_unlock:
+	mutex_unlock(&c->tnc_mutex);
+	return err;
+}
+
 /**
  * ubifs_tnc_next_ent - walk directory or extended attribute entries.
  * @c: UBIFS file-system description object
diff --git a/ubifs-utils/libubifs/ubifs.h b/ubifs-utils/libubifs/ubifs.h
index 8a506a8..03150cd 100644
--- a/ubifs-utils/libubifs/ubifs.h
+++ b/ubifs-utils/libubifs/ubifs.h
@@ -1661,6 +1661,8 @@ int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key,
 int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key,
 			   union ubifs_key *to_key);
 int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum);
+int ubifs_tnc_remove_node(struct ubifs_info *c, const union ubifs_key *key,
+			  int lnum, int offs);
 struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c,
 					   union ubifs_key *key,
 					   const struct fscrypt_name *nm);
-- 
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