Enable Postgres data checksums (neondatabase/cloud#536)

We need checksums to verify data integrity, when we read it from
untrusted place (e.g. local disk) or via untrusted communication channel
(e.g. network). At the same time, we trust pageserver <-> redo process
communication channel, as it is just a pipe.

Here we enable calculation of data checksums in the wal redo process and
when we extract FPI during WAL injestion. Compute node (Postgres) will
verify checksum of every page after receiving it back from pageserver.
So it is pretty similar to how vanilla Postgres checks them.

There are two other places where we should verify checksums to
detect data corruption earlier:
- when we receive WAL records from safekeepers (already implemented,
  see: WalStreamDecoder::poll_decode)
- when we write layer files to disk and read back in memory from local
  disk or S3

libs/postgres_ffi/wal_generate/src/lib.rs

@@ -55,6 +55,7 @@ impl Conf {
         let output = self
             .new_pg_command("initdb")?
             .arg("-D")
+            .arg("--data-checksums")
             .arg(self.datadir.as_os_str())
             .args(&["-U", "postgres", "--no-instructions", "--no-sync"])
             .output()?;

libs/utils/scripts/restore_from_wal.sh

@@ -5,7 +5,7 @@ DATA_DIR=$3
 PORT=$4
 SYSID=`od -A n -j 24 -N 8 -t d8 $WAL_PATH/000000010000000000000002* | cut -c 3-`
 rm -fr $DATA_DIR
-env -i LD_LIBRARY_PATH=$PG_BIN/../lib $PG_BIN/initdb -E utf8 -U cloud_admin -D $DATA_DIR --sysid=$SYSID
+env -i LD_LIBRARY_PATH=$PG_BIN/../lib $PG_BIN/initdb -E utf8 -U cloud_admin -D $DATA_DIR --data-checksums --sysid=$SYSID
 echo port=$PORT >> $DATA_DIR/postgresql.conf
 REDO_POS=0x`$PG_BIN/pg_controldata -D $DATA_DIR | fgrep "REDO location"| cut -c 42-`
 declare -i WAL_SIZE=$REDO_POS+114

pageserver/src/timelines.rs

@@ -253,6 +253,7 @@ fn run_initdb(conf: &'static PageServerConf, initdbpath: &Path) -> Result<()> {
         .args(&["-D", &initdbpath.to_string_lossy()])
         .args(&["-U", &conf.superuser])
         .args(&["-E", "utf8"])
+        .arg("--data-checksums")
         .arg("--no-instructions")
         // This is only used for a temporary installation that is deleted shortly after,
         // so no need to fsync it

pageserver/src/walredo.rs

@@ -619,6 +619,7 @@ impl PostgresRedoProcess {
         info!("running initdb in {:?}", datadir.display());
         let initdb = Command::new(conf.pg_bin_dir().join("initdb"))
             .args(&["-D", &datadir.to_string_lossy()])
+            .arg("--data-checksums")
             .arg("-N")
             .env_clear()
             .env("LD_LIBRARY_PATH", conf.pg_lib_dir())

test_runner/README.md

@@ -37,7 +37,7 @@ You can run all the tests with:
 
 If you want to run all the tests in a particular file:
 
-`./scripts/pytest test_pgbench.py`
+`./scripts/pytest test_runner/batch_others/test_restart_compute.py`
 
 If you want to run all tests that have the string "bench" in their names:
 

test_runner/batch_others/test_wal_acceptor.py

@@ -682,7 +682,7 @@ class ProposerPostgres(PgProtocol):
     def initdb(self):
         """ Run initdb """
 
-        args = ["initdb", "-U", "cloud_admin", "-D", self.pg_data_dir_path()]
+        args = ["initdb", "-U", "cloud_admin", "-D", self.pg_data_dir_path(), "--data-checksums"]
         self.pg_bin.run(args)
 
     def start(self):