ufs: fix handling of delete_entry and set_link failures

similar to minixfs series - make ufs_set_link() report failures,
lift folio_release_kmap() into the callers of ufs_set_link()
and ufs_delete_entry(), make ufs_rename() handle failures in both.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

fs/ufs/dir.c

@@ -81,28 +81,29 @@ ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
 }
 
 
-/* Releases the page */
-void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
-		  struct folio *folio, struct inode *inode,
-		  bool update_times)
+int ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
+		 struct folio *folio, struct inode *inode,
+		 bool update_times)
 {
 	loff_t pos = folio_pos(folio) + offset_in_folio(folio, de);
 	unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen);
 	int err;
 
 	folio_lock(folio);
 	err = ufs_prepare_chunk(folio, pos, len);
-	BUG_ON(err);
+	if (unlikely(err)) {
+		folio_unlock(folio);
+		return err;
+	}
 
 	de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
 	ufs_set_de_type(dir->i_sb, de, inode->i_mode);
 
 	ufs_commit_chunk(folio, pos, len);
-	folio_release_kmap(folio, de);
 	if (update_times)
 		inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 	mark_inode_dirty(dir);
-	ufs_handle_dirsync(dir);
+	return ufs_handle_dirsync(dir);
 }
 
 static bool ufs_check_folio(struct folio *folio, char *kaddr)
@@ -505,8 +506,7 @@ int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
 		if (de->d_reclen == 0) {
 			ufs_error(inode->i_sb, __func__,
 				  "zero-length directory entry");
-			err = -EIO;
-			goto out;
+			return -EIO;
 		}
 		pde = de;
 		de = ufs_next_entry(sb, de);
@@ -516,18 +516,17 @@ int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
 	pos = folio_pos(folio) + from;
 	folio_lock(folio);
 	err = ufs_prepare_chunk(folio, pos, to - from);
-	BUG_ON(err);
+	if (unlikely(err)) {
+		folio_unlock(folio);
+		return err;
+	}
 	if (pde)
 		pde->d_reclen = cpu_to_fs16(sb, to - from);
 	dir->d_ino = 0;
 	ufs_commit_chunk(folio, pos, to - from);
 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
 	mark_inode_dirty(inode);
-	err = ufs_handle_dirsync(inode);
-out:
-	folio_release_kmap(folio, kaddr);
-	UFSD("EXIT\n");
-	return err;
+	return ufs_handle_dirsync(inode);
 }
 
 int ufs_make_empty(struct inode * inode, struct inode *dir)

fs/ufs/namei.c

@@ -210,20 +210,18 @@ static int ufs_unlink(struct inode *dir, struct dentry *dentry)
 	struct inode * inode = d_inode(dentry);
 	struct ufs_dir_entry *de;
 	struct folio *folio;
-	int err = -ENOENT;
+	int err;
 
 	de = ufs_find_entry(dir, &dentry->d_name, &folio);
 	if (!de)
-		goto out;
+		return -ENOENT;
 
 	err = ufs_delete_entry(dir, de, folio);
-	if (err)
-		goto out;
-
-	inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
-	inode_dec_link_count(inode);
-	err = 0;
-out:
+	if (!err) {
+		inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
+		inode_dec_link_count(inode);
+	}
+	folio_release_kmap(folio, de);
 	return err;
 }
 
@@ -253,14 +251,14 @@ static int ufs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 	struct ufs_dir_entry * dir_de = NULL;
 	struct folio *old_folio;
 	struct ufs_dir_entry *old_de;
-	int err = -ENOENT;
+	int err;
 
 	if (flags & ~RENAME_NOREPLACE)
 		return -EINVAL;
 
 	old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_folio);
 	if (!old_de)
-		goto out;
+		return -ENOENT;
 
 	if (S_ISDIR(old_inode->i_mode)) {
 		err = -EIO;
@@ -281,7 +279,10 @@ static int ufs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_folio);
 		if (!new_de)
 			goto out_dir;
-		ufs_set_link(new_dir, new_de, new_folio, old_inode, 1);
+		err = ufs_set_link(new_dir, new_de, new_folio, old_inode, 1);
+		folio_release_kmap(new_folio, new_de);
+		if (err)
+			goto out_dir;
 		inode_set_ctime_current(new_inode);
 		if (dir_de)
 			drop_nlink(new_inode);
@@ -299,26 +300,20 @@ static int ufs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
  	 * rename.
 	 */
 	inode_set_ctime_current(old_inode);
-
-	ufs_delete_entry(old_dir, old_de, old_folio);
 	mark_inode_dirty(old_inode);
 
-	if (dir_de) {
+	err = ufs_delete_entry(old_dir, old_de, old_folio);
+	if (!err && dir_de) {
 		if (old_dir != new_dir)
-			ufs_set_link(old_inode, dir_de, dir_folio, new_dir, 0);
-		else
-			folio_release_kmap(dir_folio, dir_de);
+			err = ufs_set_link(old_inode, dir_de, dir_folio,
+					   new_dir, 0);
 		inode_dec_link_count(old_dir);
 	}
-	return 0;
-
-
 out_dir:
 	if (dir_de)
 		folio_release_kmap(dir_folio, dir_de);
 out_old:
 	folio_release_kmap(old_folio, old_de);
-out:
 	return err;
 }
 

fs/ufs/ufs.h

@@ -108,8 +108,8 @@ struct ufs_dir_entry *ufs_find_entry(struct inode *, const struct qstr *,
 int ufs_delete_entry(struct inode *, struct ufs_dir_entry *, struct folio *);
 int ufs_empty_dir(struct inode *);
 struct ufs_dir_entry *ufs_dotdot(struct inode *, struct folio **);
-void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
-		struct folio *folio, struct inode *inode, bool update_times);
+int ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
+		 struct folio *folio, struct inode *inode, bool update_times);
 
 /* file.c */
 extern const struct inode_operations ufs_file_inode_operations;