Inside Bitcoin

1#!/usr/bin/env python3
2# Copyright (c) 2023-present The Bitcoin Core developers
3# Distributed under the MIT software license, see the accompanying
4# file COPYING or http://www.opensource.org/licenses/mit-license.php.
5"""Test running bitcoind with -reindex from a read-only blockstore
6- Start a node, generate blocks, then restart with -reindex after setting blk files to read-only
7"""
8
9import os
10import stat
11import subprocess
12from test_framework.test_framework import BitcoinTestFramework
13from test_framework.util import assert_equal
14
15
16class BlockstoreReindexTest(BitcoinTestFramework):
17    def set_test_params(self):
18        self.setup_clean_chain = True
19        self.num_nodes = 1
20        self.extra_args = [["-fastprune"]]
21
22    def reindex_readonly(self):
23        self.log.debug("Generate block big enough to start second block file")
24        fastprune_blockfile_size = 0x10000
25        opreturn = "6a"
26        nulldata = fastprune_blockfile_size * "ff"
27        self.generateblock(self.nodes[0], output=f"raw({opreturn}{nulldata})", transactions=[])
28        block_count = self.nodes[0].getblockcount()
29        self.stop_node(0)
30
31        assert (self.nodes[0].chain_path / "blocks" / "blk00000.dat").exists()
32        assert (self.nodes[0].chain_path / "blocks" / "blk00001.dat").exists()
33
34        self.log.debug("Make the first block file read-only")
35        filename = self.nodes[0].chain_path / "blocks" / "blk00000.dat"
36        filename.chmod(stat.S_IREAD)
37
38        undo_immutable_cmd = None
39        should_reindex = True
40        # Linux
41        try:
42            subprocess.run(['chattr'], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
43            try:
44                subprocess.run(['chattr', '+i', filename], capture_output=True, check=True)
45                undo_immutable_cmd = ['chattr', '-i', filename]
46                self.log.info("Made file immutable with chattr")
47            except subprocess.CalledProcessError as e:
48                self.log.warning(str(e))
49                if e.stdout:
50                    self.log.warning(f"stdout: {e.stdout}")
51                if e.stderr:
52                    self.log.warning(f"stderr: {e.stderr}")
53                if os.getuid() == 0:
54                    self.log.warning("Return early on Linux under root, because chattr failed.")
55                    self.log.warning("This should only happen due to missing capabilities in a container.")
56                    self.log.warning("Make sure to --cap-add LINUX_IMMUTABLE if you want to run this test.")
57                    should_reindex = False
58        except Exception:
59            # macOS, and *BSD
60            try:
61                subprocess.run(['chflags'], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
62                try:
63                    subprocess.run(['chflags', 'uchg', filename], capture_output=True, check=True)
64                    undo_immutable_cmd = ['chflags', 'nouchg', filename]
65                    self.log.info("Made file immutable with chflags")
66                except subprocess.CalledProcessError as e:
67                    self.log.warning(str(e))
68                    if e.stdout:
69                        self.log.warning(f"stdout: {e.stdout}")
70                    if e.stderr:
71                        self.log.warning(f"stderr: {e.stderr}")
72                    if os.getuid() == 0:
73                        self.log.warning("Return early on BSD under root, because chflags failed.")
74                        should_reindex = False
75            except Exception:
76                pass
77
78        if should_reindex:
79            self.log.debug("Attempt to restart and reindex the node with the unwritable block file")
80            with self.nodes[0].assert_debug_log(["Reindexing finished"], timeout=60):
81                self.start_node(0, extra_args=['-reindex', '-fastprune'])
82            assert_equal(block_count, self.nodes[0].getblockcount())
83            if undo_immutable_cmd is not None:
84                subprocess.check_call(undo_immutable_cmd)
85
86        filename.chmod(0o777)
87
88    def run_test(self):
89        self.reindex_readonly()
90
91
92if __name__ == '__main__':
93    BlockstoreReindexTest(__file__).main()
94