From 5f771fcc396ba21171bff8b15e7c49d437f6bf85 Mon Sep 17 00:00:00 2001 From: Daniel Gustafsson Date: Mon, 16 Dec 2019 15:06:25 +0100 Subject: [PATCH] Online enable and disable of data checksums This allows data checksums to be enabled, or disabled, in a running cluster without requiring a restart. The data checksum mode will be set to "inprogress" while the checksumhelper background worker walks the database and rewrites all the data pages to include checksums. Once all pages have been checksummed, the data checksum mode turns to "on". The synchronization of the checksumhelper is based on the procbarrier infrastructure. This adds a new section in the documention for checksums, covering the basics on how to enable and disable with the various means that are possible. More information can probably be added covering other aspects of data checksums. In passing, this patch removes the SAMPLE procbarrier and replaces it with the CHECKSUM procbarrier, as there is now a consumer of the procbarrier API and the "dummy" barrier can be removed (it was needed to keep the enum with something). --- doc/src/sgml/func.sgml | 65 ++ doc/src/sgml/ref/initdb.sgml | 1 + doc/src/sgml/wal.sgml | 96 +++ src/backend/access/rmgrdesc/xlogdesc.c | 16 + src/backend/access/transam/xlog.c | 130 ++- src/backend/access/transam/xlogfuncs.c | 57 ++ src/backend/catalog/system_views.sql | 5 + src/backend/postmaster/Makefile | 1 + src/backend/postmaster/bgworker.c | 7 + src/backend/postmaster/checksumhelper.c | 909 ++++++++++++++++++++ src/backend/postmaster/pgstat.c | 6 + src/backend/replication/basebackup.c | 2 +- src/backend/replication/logical/decode.c | 1 + src/backend/storage/ipc/ipci.c | 2 + src/backend/storage/ipc/procsignal.c | 20 +- src/backend/storage/lmgr/lwlocknames.txt | 1 + src/backend/storage/page/README | 3 +- src/backend/storage/page/bufpage.c | 6 +- src/backend/utils/adt/pgstatfuncs.c | 4 +- src/backend/utils/misc/guc.c | 36 +- src/bin/pg_upgrade/controldata.c | 9 + src/bin/pg_upgrade/pg_upgrade.h | 2 +- src/include/access/xlog.h | 10 +- src/include/access/xlog_internal.h | 7 + src/include/catalog/pg_control.h | 1 + src/include/catalog/pg_proc.dat | 16 + src/include/pgstat.h | 4 +- src/include/postmaster/checksumhelper.h | 31 + src/include/storage/bufpage.h | 1 + src/include/storage/checksum.h | 7 + src/include/storage/procsignal.h | 2 +- src/test/Makefile | 3 +- src/test/checksum/.gitignore | 2 + src/test/checksum/Makefile | 24 + src/test/checksum/README | 22 + src/test/checksum/t/001_standby_checksum.pl | 104 +++ 36 files changed, 1570 insertions(+), 43 deletions(-) create mode 100644 src/backend/postmaster/checksumhelper.c create mode 100644 src/include/postmaster/checksumhelper.h create mode 100644 src/test/checksum/.gitignore create mode 100644 src/test/checksum/Makefile create mode 100644 src/test/checksum/README create mode 100644 src/test/checksum/t/001_standby_checksum.pl diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 57a1539506..05a1c393ed 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21265,6 +21265,71 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup()); + + Data Checksum Functions + + + The functions shown in can + be used to enable or disable data checksums in a running cluster. + See for details. + + + + Checksum <acronym>SQL</acronym> Functions + + + + Function + Return Type + Description + + + + + + + pg_enable_data_checksums + + pg_enable_data_checksums(cost_delay int, cost_limit int) + + + void + + + + Initiates data checksums for the cluster. This will switch the data checksums mode + to inprogress as well as start a background worker that will process + all data in the database and enable checksums for it. When all data pages have had + checksums enabled, the cluster will automatically switch data checksums mode to + on. + + + If cost_delay and cost_limit are + specified, the speed of the process is throttled using the same principles as + Cost-based Vacuum Delay. + + + + + + + pg_disable_data_checksums + + pg_disable_data_checksums() + + + void + + + Disables data checksums for the cluster. + + + + +
+ + + Database Object Management Functions diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml index da5c8f5307..69b7f91cbc 100644 --- a/doc/src/sgml/ref/initdb.sgml +++ b/doc/src/sgml/ref/initdb.sgml @@ -220,6 +220,7 @@ PostgreSQL documentation are calculated for all objects, in all databases. All checksum failures will be reported in the view. + See for details. diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml index 4eb8feb903..505c422af2 100644 --- a/doc/src/sgml/wal.sgml +++ b/doc/src/sgml/wal.sgml @@ -230,6 +230,102 @@ + + Data Checksums + + checksums + + + + Data pages are not checksum protected by default, but this can optionally be + enabled for a cluster. When enabled, each data page will be assigned a + checksum that is updated when the page is written and verified every time + the page is read. Only data pages are protected by checksums, internal data + structures and temporary files are not. + + + + Checksums are normally enabled when the cluster is initialized using initdb. + They can also be enabled or disabled at a later timne, either as an offline + operation or in a running cluster. In all cases, checksums are enabled or + disabled at the full cluster level, and cannot be specified individually for + databases or tables. + + + + The current state of checksums in the cluster can be verified by viewing the + value of the read-only configuration variable by issuing the command SHOW + data_checksums. + + + + When attempting to recover from corrupt data it may be necessary to bypass + the checksum protection in order to recover data. To do this, temporarily + set the configuration parameter . + + + + On-line Enabling of Checksums + + + Checksums can be enabled or disabled online, by calling the appropriate + functions. + Disabling of checksums takes effect immediately when the function is called. + + + + Enabling checksums will put the cluster checksum mode in + inprogress mode. During this time, checksums will be + written but not verified. In addition to this, a background worker process + is started that enables checksums on all existing data in the cluster. Once + this worker has completed processing all databases in the cluster, the + checksum mode will automatically switch to on. + + + + The process will initially wait for all open transactions to finish before + it starts, so that it can be certain that there are no tables that have been + created inside a transaction that has not committed yet and thus would not + be visible to the process enabling checksums. It will also, for each database, + wait for all pre-existing temporary tables to get removed before it finishes. + If long-lived temporary tables are used in the application it may be necessary + to terminate these application connections to allow the process to complete. + Information about open transactions and connections with temporary tables is + written to log. + + + + If the cluster is stopped while in inprogress mode, for + any reason, then this process must be restarted manually. To do this, + re-execute the function pg_enable_data_checksums() + once the cluster has been restarted. It is not possible to resume the work, + the process has to start over from the beginning. + + + + + Enabling checksums can cause significant I/O to the system, as most of the + database pages will need to be rewritten, and will be written both to the + data files and the WAL. + + + + + + + Off-line Enabling of Checksums + + + The pg_checksums + application can be used to enable or disable data checksums, as well as + verify checksums, on an offline cluster. + + + + + Write-Ahead Logging (<acronym>WAL</acronym>) diff --git a/src/backend/access/rmgrdesc/xlogdesc.c b/src/backend/access/rmgrdesc/xlogdesc.c index 33060f3042..ced4ab6d78 100644 --- a/src/backend/access/rmgrdesc/xlogdesc.c +++ b/src/backend/access/rmgrdesc/xlogdesc.c @@ -18,6 +18,7 @@ #include "access/xlog.h" #include "access/xlog_internal.h" #include "catalog/pg_control.h" +#include "storage/bufpage.h" #include "utils/guc.h" #include "utils/timestamp.h" @@ -140,6 +141,18 @@ xlog_desc(StringInfo buf, XLogReaderState *record) xlrec.ThisTimeLineID, xlrec.PrevTimeLineID, timestamptz_to_str(xlrec.end_time)); } + else if (info == XLOG_CHECKSUMS) + { + xl_checksum_state xlrec; + + memcpy(&xlrec, rec, sizeof(xl_checksum_state)); + if (xlrec.new_checksumtype == PG_DATA_CHECKSUM_VERSION) + appendStringInfo(buf, "on"); + else if (xlrec.new_checksumtype == PG_DATA_CHECKSUM_INPROGRESS_VERSION) + appendStringInfo(buf, "inprogress"); + else + appendStringInfo(buf, "off"); + } } const char * @@ -185,6 +198,9 @@ xlog_identify(uint8 info) case XLOG_FPI_FOR_HINT: id = "FPI_FOR_HINT"; break; + case XLOG_CHECKSUMS: + id = "CHECKSUMS"; + break; } return id; diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 6bc1a6b46d..5d5b2ea2d9 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -867,6 +867,7 @@ static void SetLatestXTime(TimestampTz xtime); static void SetCurrentChunkStartTime(TimestampTz xtime); static void CheckRequiredParameterValues(void); static void XLogReportParameters(void); +static void XlogChecksums(ChecksumType new_type); static void checkTimeLineSwitch(XLogRecPtr lsn, TimeLineID newTLI, TimeLineID prevTLI); static void LocalSetXLogInsertAllowed(void); @@ -1049,7 +1050,7 @@ XLogInsertRecord(XLogRecData *rdata, Assert(RedoRecPtr < Insert->RedoRecPtr); RedoRecPtr = Insert->RedoRecPtr; } - doPageWrites = (Insert->fullPageWrites || Insert->forcePageWrites); + doPageWrites = (Insert->fullPageWrites || Insert->forcePageWrites || DataChecksumsInProgress()); if (doPageWrites && (!prevDoPageWrites || @@ -4776,10 +4777,6 @@ ReadControlFile(void) (SizeOfXLogLongPHD - SizeOfXLogShortPHD); CalculateCheckpointSegments(); - - /* Make the initdb settings visible as GUC variables, too */ - SetConfigOption("data_checksums", DataChecksumsEnabled() ? "yes" : "no", - PGC_INTERNAL, PGC_S_OVERRIDE); } /* @@ -4816,12 +4813,93 @@ GetMockAuthenticationNonce(void) * Are checksums enabled for data pages? */ bool -DataChecksumsEnabled(void) +DataChecksumsNeedWrite(void) { Assert(ControlFile != NULL); return (ControlFile->data_checksum_version > 0); } +bool +DataChecksumsNeedVerify(void) +{ + Assert(ControlFile != NULL); + + /* + * Only verify checksums if they are fully enabled in the cluster. In + * inprogress state they are only updated, not verified. + */ + return (ControlFile->data_checksum_version == PG_DATA_CHECKSUM_VERSION); +} + +bool +DataChecksumsInProgress(void) +{ + Assert(ControlFile != NULL); + return (ControlFile->data_checksum_version == PG_DATA_CHECKSUM_INPROGRESS_VERSION); +} + +void +SetDataChecksumsInProgress(void) +{ + Assert(ControlFile != NULL); + if (ControlFile->data_checksum_version > 0) + return; + + XlogChecksums(PG_DATA_CHECKSUM_INPROGRESS_VERSION); + + LWLockAcquire(ControlFileLock, LW_EXCLUSIVE); + ControlFile->data_checksum_version = PG_DATA_CHECKSUM_INPROGRESS_VERSION; + UpdateControlFile(); + LWLockRelease(ControlFileLock); + WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_CHECKSUM)); +} + +void +SetDataChecksumsOn(void) +{ + Assert(ControlFile != NULL); + + LWLockAcquire(ControlFileLock, LW_EXCLUSIVE); + + if (ControlFile->data_checksum_version != PG_DATA_CHECKSUM_INPROGRESS_VERSION) + { + LWLockRelease(ControlFileLock); + elog(ERROR, "Checksums not in inprogress mode"); + } + + ControlFile->data_checksum_version = PG_DATA_CHECKSUM_VERSION; + UpdateControlFile(); + LWLockRelease(ControlFileLock); + WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_CHECKSUM)); + + XlogChecksums(PG_DATA_CHECKSUM_VERSION); +} + +void +SetDataChecksumsOff(void) +{ + LWLockAcquire(ControlFileLock, LW_EXCLUSIVE); + + ControlFile->data_checksum_version = 0; + UpdateControlFile(); + LWLockRelease(ControlFileLock); + WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_CHECKSUM)); + + XlogChecksums(0); +} + +/* guc hook */ +const char * +show_data_checksums(void) +{ + if (ControlFile->data_checksum_version == PG_DATA_CHECKSUM_VERSION) + return "on"; + else if (ControlFile->data_checksum_version == PG_DATA_CHECKSUM_INPROGRESS_VERSION) + return "inprogress"; + else + return "off"; +} + /* * Returns a fake LSN for unlogged relations. * @@ -7782,6 +7860,17 @@ StartupXLOG(void) */ CompleteCommitTsInitialization(); + /* + * If we reach this point with checksums in inprogress state, we notify + * the user that they need to manually restart the process to enable + * checksums. This is because we cannot launch a dynamic background worker + * directly from here, it has to be launched from a regular backend. + */ + if (ControlFile->data_checksum_version == PG_DATA_CHECKSUM_INPROGRESS_VERSION) + ereport(WARNING, + (errmsg("checksum state is \"inprogress\" with no worker"), + errhint("Either disable or enable checksums by calling the pg_disable_data_checksums() or pg_enable_data_checksums() functions."))); + /* * All done with end-of-recovery actions. * @@ -9505,6 +9594,24 @@ XLogReportParameters(void) } } +/* + * Log the new state of checksums + */ +static void +XlogChecksums(ChecksumType new_type) +{ + xl_checksum_state xlrec; + XLogRecPtr recptr; + + xlrec.new_checksumtype = new_type; + + XLogBeginInsert(); + XLogRegisterData((char *) &xlrec, sizeof(xl_checksum_state)); + + recptr = XLogInsert(RM_XLOG_ID, XLOG_CHECKSUMS); + XLogFlush(recptr); +} + /* * Update full_page_writes in shared memory, and write an * XLOG_FPW_CHANGE record if necessary. @@ -9956,6 +10063,17 @@ xlog_redo(XLogReaderState *record) /* Keep track of full_page_writes */ lastFullPageWrites = fpw; } + else if (info == XLOG_CHECKSUMS) + { + xl_checksum_state state; + + memcpy(&state, XLogRecGetData(record), sizeof(xl_checksum_state)); + + LWLockAcquire(ControlFileLock, LW_EXCLUSIVE); + ControlFile->data_checksum_version = state.new_checksumtype; + UpdateControlFile(); + LWLockRelease(ControlFileLock); + } } #ifdef WAL_DEBUG diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c index 1fccf29a36..02dd3cf383 100644 --- a/src/backend/access/transam/xlogfuncs.c +++ b/src/backend/access/transam/xlogfuncs.c @@ -25,6 +25,7 @@ #include "catalog/pg_type.h" #include "funcapi.h" #include "miscadmin.h" +#include "postmaster/checksumhelper.h" #include "pgstat.h" #include "replication/walreceiver.h" #include "storage/fd.h" @@ -784,3 +785,59 @@ pg_promote(PG_FUNCTION_ARGS) (errmsg("server did not promote within %d seconds", wait_seconds))); PG_RETURN_BOOL(false); } + +/* + * Disables checksums for the cluster, unless already disabled. + * + * Has immediate effect - the checksums are set to off right away. + */ +Datum +disable_data_checksums(PG_FUNCTION_ARGS) +{ + /* + * If we don't need to write new checksums, then clearly they are already + * disabled. + */ + if (!DataChecksumsNeedWrite()) + ereport(ERROR, + (errmsg("data checksums already disabled"))); + + ShutdownChecksumHelperIfRunning(); + + SetDataChecksumsOff(); + + PG_RETURN_VOID(); +} + +/* + * Enables checksums for the cluster, unless already enabled. + * + * Supports vacuum-like cost-based throttling, to limit system load. + * Starts a background worker that updates checksums on existing data. + */ +Datum +enable_data_checksums(PG_FUNCTION_ARGS) +{ + int cost_delay = PG_GETARG_INT32(0); + int cost_limit = PG_GETARG_INT32(1); + + if (cost_delay < 0) + ereport(ERROR, + (errmsg("cost delay cannot be less than zero"))); + if (cost_limit <= 0) + ereport(ERROR, + (errmsg("cost limit must be a positive value"))); + + /* + * Allow state change from "off" or from "inprogress", since this is how + * we restart the worker if necessary. + */ + if (DataChecksumsNeedVerify()) + ereport(ERROR, + (errmsg("data checksums already enabled"))); + + SetDataChecksumsInProgress(); + StartChecksumHelperLauncher(cost_delay, cost_limit); + + PG_RETURN_VOID(); +} diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index f7800f01a6..1d4660597a 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -1160,6 +1160,11 @@ CREATE OR REPLACE FUNCTION RETURNS boolean STRICT VOLATILE LANGUAGE INTERNAL AS 'pg_promote' PARALLEL SAFE; +CREATE OR REPLACE FUNCTION pg_enable_data_checksums ( + cost_delay int DEFAULT 0, cost_limit int DEFAULT 100) + RETURNS void STRICT VOLATILE LANGUAGE internal AS 'enable_data_checksums' + PARALLEL RESTRICTED; + -- legacy definition for compatibility with 9.3 CREATE OR REPLACE FUNCTION json_populate_record(base anyelement, from_json json, use_json_as_text boolean DEFAULT false) diff --git a/src/backend/postmaster/Makefile b/src/backend/postmaster/Makefile index bfdf6a833d..73df17e5f3 100644 --- a/src/backend/postmaster/Makefile +++ b/src/backend/postmaster/Makefile @@ -17,6 +17,7 @@ OBJS = \ bgworker.o \ bgwriter.o \ checkpointer.o \ + checksumhelper.o \ fork_process.o \ interrupt.o \ pgarch.o \ diff --git a/src/backend/postmaster/bgworker.c b/src/backend/postmaster/bgworker.c index a4c347d524..1bf1e1a49e 100644 --- a/src/backend/postmaster/bgworker.c +++ b/src/backend/postmaster/bgworker.c @@ -18,6 +18,7 @@ #include "pgstat.h" #include "port/atomics.h" #include "postmaster/bgworker_internals.h" +#include "postmaster/checksumhelper.h" #include "postmaster/interrupt.h" #include "postmaster/postmaster.h" #include "replication/logicallauncher.h" @@ -128,6 +129,12 @@ static const struct }, { "ApplyWorkerMain", ApplyWorkerMain + }, + { + "ChecksumHelperLauncherMain", ChecksumHelperLauncherMain + }, + { + "ChecksumHelperWorkerMain", ChecksumHelperWorkerMain } }; diff --git a/src/backend/postmaster/checksumhelper.c b/src/backend/postmaster/checksumhelper.c new file mode 100644 index 0000000000..f5c9ac3283 --- /dev/null +++ b/src/backend/postmaster/checksumhelper.c @@ -0,0 +1,909 @@ +/*------------------------------------------------------------------------- + * + * checksumhelper.c + * Background worker to walk the database and write checksums to pages + * + * When enabling data checksums on a database at initdb time or with + * pg_checksums, no extra process is required as each page is checksummed, and + * verified, at accesses. When enabling checksums on an already running + * cluster, which was not initialized with checksums, this helper worker will + * ensure that all pages are checksummed before verification of the checksums + * is turned on. + * + * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/postmaster/checksumhelper.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/heapam.h" +#include "access/htup_details.h" +#include "access/xact.h" +#include "catalog/pg_database.h" +#include "commands/vacuum.h" +#include "common/relpath.h" +#include "miscadmin.h" +#include "pgstat.h" +#include "postmaster/bgworker.h" +#include "postmaster/bgwriter.h" +#include "postmaster/checksumhelper.h" +#include "storage/bufmgr.h" +#include "storage/checksum.h" +#include "storage/lmgr.h" +#include "storage/ipc.h" +#include "storage/procarray.h" +#include "storage/smgr.h" +#include "tcop/tcopprot.h" +#include "utils/lsyscache.h" +#include "utils/ps_status.h" + + +typedef enum +{ + SUCCESSFUL = 0, + ABORTED, + FAILED +} ChecksumHelperResult; + +typedef struct ChecksumHelperShmemStruct +{ + /* + * Access to launcher_started and abort must be protected by + * ChecksumHelperLock. + */ + bool launcher_started; + bool abort; + + /* + * Access to other members can be done without a lock, as while they are + * in shared memory, they are never concurrently accessed. When a worker + * is running, the launcher is only waiting for that worker to finish. + */ + ChecksumHelperResult success; + bool process_shared_catalogs; + /* Parameter values set on start */ + int cost_delay; + int cost_limit; +} ChecksumHelperShmemStruct; + +/* Shared memory segment for checksumhelper */ +static ChecksumHelperShmemStruct * ChecksumHelperShmem; + +/* Bookkeeping for work to do */ +typedef struct ChecksumHelperDatabase +{ + Oid dboid; + char *dbname; +} ChecksumHelperDatabase; + +typedef struct ChecksumHelperRelation +{ + Oid reloid; + char relkind; +} ChecksumHelperRelation; + +/* Prototypes */ +static List *BuildDatabaseList(void); +static List *BuildRelationList(bool include_shared); +static List *BuildTempTableList(void); +static ChecksumHelperResult ProcessDatabase(ChecksumHelperDatabase * db); +static void launcher_cancel_handler(SIGNAL_ARGS); + +/* + * Main entry point for checksumhelper launcher process. + */ +void +StartChecksumHelperLauncher(int cost_delay, int cost_limit) +{ + BackgroundWorker bgw; + BackgroundWorkerHandle *bgw_handle; + + LWLockAcquire(ChecksumHelperLock, LW_EXCLUSIVE); + if (ChecksumHelperShmem->abort) + { + LWLockRelease(ChecksumHelperLock); + ereport(ERROR, + (errmsg("could not start checksumhelper: has been canceled"))); + } + + if (ChecksumHelperShmem->launcher_started) + { + /* Failed to set means somebody else started */ + LWLockRelease(ChecksumHelperLock); + ereport(ERROR, + (errmsg("could not start checksumhelper: already running"))); + } + + ChecksumHelperShmem->cost_delay = cost_delay; + ChecksumHelperShmem->cost_limit = cost_limit; + + memset(&bgw, 0, sizeof(bgw)); + bgw.bgw_flags = BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION; + bgw.bgw_start_time = BgWorkerStart_RecoveryFinished; + snprintf(bgw.bgw_library_name, BGW_MAXLEN, "postgres"); + snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ChecksumHelperLauncherMain"); + snprintf(bgw.bgw_name, BGW_MAXLEN, "checksumhelper launcher"); + snprintf(bgw.bgw_type, BGW_MAXLEN, "checksumhelper launcher"); + bgw.bgw_restart_time = BGW_NEVER_RESTART; + bgw.bgw_notify_pid = MyProcPid; + bgw.bgw_main_arg = (Datum) 0; + + ChecksumHelperShmem->launcher_started = true; + LWLockRelease(ChecksumHelperLock); + + if (!RegisterDynamicBackgroundWorker(&bgw, &bgw_handle)) + { + LWLockAcquire(ChecksumHelperLock, LW_EXCLUSIVE); + ChecksumHelperShmem->launcher_started = false; + LWLockRelease(ChecksumHelperLock); + ereport(ERROR, + (errmsg("failed to start checksum helper launcher"))); + } +} + +/* + * ShutdownChecksumHelperIfRunning + * Request shutdown of the checksumhelper + * + * This does not turn off processing immediately, it signals the checksum + * process to end when done with the current block. + */ +void +ShutdownChecksumHelperIfRunning(void) +{ + /* If the launcher isn't started, there is nothing to shut down */ + LWLockAcquire(ChecksumHelperLock, LW_EXCLUSIVE); + if (ChecksumHelperShmem->launcher_started) + ChecksumHelperShmem->abort = true; + LWLockRelease(ChecksumHelperLock); +} + +/* + * ProcessSingleRelationFork + * Enable checksums in a single relation/fork. + * + * Returns true if successful, and false if *aborted*. On error, an actual + * error is raised in the lower levels. + */ +static bool +ProcessSingleRelationFork(Relation reln, ForkNumber forkNum, BufferAccessStrategy strategy) +{ + BlockNumber numblocks = RelationGetNumberOfBlocksInFork(reln, forkNum); + BlockNumber b; + char activity[NAMEDATALEN * 2 + 128]; + + for (b = 0; b < numblocks; b++) + { + Buffer buf = ReadBufferExtended(reln, forkNum, b, RBM_NORMAL, strategy); + + /* + * Report to pgstat every 100 blocks (so as not to "spam") + */ + if ((b % 100) == 0) + { + snprintf(activity, sizeof(activity) - 1, "processing: %s.%s (%s block %d/%d)", + get_namespace_name(RelationGetNamespace(reln)), RelationGetRelationName(reln), + forkNames[forkNum], b, numblocks); + pgstat_report_activity(STATE_RUNNING, activity); + } + + /* Need to get an exclusive lock before we can flag as dirty */ + LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE); + + /* + * Mark the buffer as dirty and force a full page write. We have to + * re-write the page to WAL even if the checksum hasn't changed, + * because if there is a replica it might have a slightly different + * version of the page with an invalid checksum, caused by unlogged + * changes (e.g. hintbits) on the master happening while checksums + * were off. This can happen if there was a valid checksum on the page + * at one point in the past, so only when checksums are first on, then + * off, and then turned on again. + */ + START_CRIT_SECTION(); + MarkBufferDirty(buf); + log_newpage_buffer(buf, false); + END_CRIT_SECTION(); + + UnlockReleaseBuffer(buf); + + /* + * This is the only place where we check if we are asked to abort, the + * abortion will bubble up from here. It's safe to check this without + * a lock, because if we miss it being set, we will try again soon. + */ + if (ChecksumHelperShmem->abort) + return false; + + vacuum_delay_point(); + } + + return true; +} + +/* + * ProcessSingleRelationByOid + * Process a single relation based on oid. + * + * Returns true if successful, and false if *aborted*. On error, an actual error + * is raised in the lower levels. + */ +static bool +ProcessSingleRelationByOid(Oid relationId, BufferAccessStrategy strategy) +{ + Relation rel; + ForkNumber fnum; + bool aborted = false; + + StartTransactionCommand(); + + elog(DEBUG2, "Checksumhelper starting to process relation %d", relationId); + rel = try_relation_open(relationId, AccessShareLock); + if (rel == NULL) + { + /* + * Relation no longer exist. We consider this a success, since there + * are no pages in it that need checksums, and thus return true. + */ + elog(DEBUG1, "Checksumhelper skipping relation %d as it no longer exists", relationId); + CommitTransactionCommand(); + pgstat_report_activity(STATE_IDLE, NULL); + return true; + } + RelationOpenSmgr(rel); + + for (fnum = 0; fnum <= MAX_FORKNUM; fnum++) + { + if (smgrexists(rel->rd_smgr, fnum)) + { + if (!ProcessSingleRelationFork(rel, fnum, strategy)) + { + aborted = true; + break; + } + } + } + relation_close(rel, AccessShareLock); + elog(DEBUG2, "Checksumhelper done with relation %d: %s", + relationId, (aborted ? "aborted" : "finished")); + + CommitTransactionCommand(); + + pgstat_report_activity(STATE_IDLE, NULL); + + return !aborted; +} + +/* + * ProcessDatabase + * Enable checksums in a single database. + * + * We do this by launching a dynamic background worker into this database, and + * waiting for it to finish. We have to do this in a separate worker, since + * each process can only be connected to one database during its lifetime. + */ +static ChecksumHelperResult +ProcessDatabase(ChecksumHelperDatabase * db) +{ + BackgroundWorker bgw; + BackgroundWorkerHandle *bgw_handle; + BgwHandleStatus status; + pid_t pid; + char activity[NAMEDATALEN + 64]; + + ChecksumHelperShmem->success = FAILED; + + memset(&bgw, 0, sizeof(bgw)); + bgw.bgw_flags = BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION; + bgw.bgw_start_time = BgWorkerStart_RecoveryFinished; + snprintf(bgw.bgw_library_name, BGW_MAXLEN, "postgres"); + snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ChecksumHelperWorkerMain"); + snprintf(bgw.bgw_name, BGW_MAXLEN, "checksumhelper worker"); + snprintf(bgw.bgw_type, BGW_MAXLEN, "checksumhelper worker"); + bgw.bgw_restart_time = BGW_NEVER_RESTART; + bgw.bgw_notify_pid = MyProcPid; + bgw.bgw_main_arg = ObjectIdGetDatum(db->dboid); + + if (!RegisterDynamicBackgroundWorker(&bgw, &bgw_handle)) + { + ereport(LOG, + (errmsg("failed to start worker for checksumhelper in \"%s\"", + db->dbname))); + return FAILED; + } + + status = WaitForBackgroundWorkerStartup(bgw_handle, &pid); + if (status != BGWH_STARTED) + { + ereport(LOG, + (errmsg("failed to wait for worker startup for checksumhelper in \"%s\"", + db->dbname))); + return FAILED; + } + + ereport(DEBUG1, + (errmsg("started background worker for checksums in \"%s\"", + db->dbname))); + + snprintf(activity, sizeof(activity) - 1, + "Waiting for worker in database %s (pid %d)", db->dbname, pid); + pgstat_report_activity(STATE_RUNNING, activity); + + + status = WaitForBackgroundWorkerShutdown(bgw_handle); + if (status != BGWH_STOPPED) + { + ereport(LOG, + (errmsg("failed to wait for worker shutdown for checksumhelper in \"%s\"", + db->dbname))); + return FAILED; + } + + if (ChecksumHelperShmem->success == ABORTED) + ereport(LOG, + (errmsg("checksumhelper was aborted during processing in \"%s\"", + db->dbname))); + + ereport(DEBUG1, + (errmsg("background worker for checksums in \"%s\" completed", + db->dbname))); + + pgstat_report_activity(STATE_IDLE, NULL); + + return ChecksumHelperShmem->success; +} + +static void +launcher_exit(int code, Datum arg) +{ + LWLockAcquire(ChecksumHelperLock, LW_EXCLUSIVE); + ChecksumHelperShmem->abort = false; + ChecksumHelperShmem->launcher_started = false; + LWLockRelease(ChecksumHelperLock); +} + +static void +launcher_cancel_handler(SIGNAL_ARGS) +{ + LWLockAcquire(ChecksumHelperLock, LW_EXCLUSIVE); + ChecksumHelperShmem->abort = true; + LWLockRelease(ChecksumHelperLock); +} + +static void +WaitForAllTransactionsToFinish(void) +{ + TransactionId waitforxid; + + LWLockAcquire(XidGenLock, LW_SHARED); + waitforxid = XidFromFullTransactionId(ShmemVariableCache->nextFullXid); + LWLockRelease(XidGenLock); + + while (true) + { + TransactionId oldestxid = GetOldestActiveTransactionId(); + + elog(DEBUG1, "Checking old transactions"); + if (TransactionIdPrecedes(oldestxid, waitforxid)) + { + char activity[64]; + + /* Oldest running xid is older than us, so wait */ + snprintf(activity, sizeof(activity), "Waiting for current transactions to finish (waiting for %d)", waitforxid); + pgstat_report_activity(STATE_RUNNING, activity); + + /* Retry every 5 seconds */ + ResetLatch(MyLatch); + (void) WaitLatch(MyLatch, + WL_LATCH_SET | WL_TIMEOUT, + 5000, + WAIT_EVENT_PG_SLEEP); + } + else + { + pgstat_report_activity(STATE_IDLE, NULL); + return; + } + } +} + +void +ChecksumHelperLauncherMain(Datum arg) +{ + List *DatabaseList; + HTAB *ProcessedDatabases = NULL; + List *FailedDatabases = NIL; + ListCell *lc, + *lc2; + HASHCTL hash_ctl; + bool found_failed = false; + + on_shmem_exit(launcher_exit, 0); + + ereport(DEBUG1, + (errmsg("checksumhelper launcher started"))); + + pqsignal(SIGTERM, die); + pqsignal(SIGINT, launcher_cancel_handler); + + BackgroundWorkerUnblockSignals(); + + init_ps_display(pgstat_get_backend_desc(B_CHECKSUMHELPER_LAUNCHER), "", "", ""); + + memset(&hash_ctl, 0, sizeof(hash_ctl)); + hash_ctl.keysize = sizeof(Oid); + hash_ctl.entrysize = sizeof(ChecksumHelperResult); + ProcessedDatabases = hash_create("Processed databases", + 64, + &hash_ctl, + HASH_ELEM); + + /* + * Initialize a connection to shared catalogs only. + */ + BackgroundWorkerInitializeConnection(NULL, NULL, 0); + + /* + * Set up so first run processes shared catalogs, but not once in every + * db. + */ + ChecksumHelperShmem->process_shared_catalogs = true; + + while (true) + { + int processed_databases; + + /* + * Get a list of all databases to process. This may include databases + * that were created during our runtime. + * + * Since a database can be created as a copy of any other database + * (which may not have existed in our last run), we have to repeat + * this loop until no new databases show up in the list. Since we wait + * for all pre-existing transactions finish, this way we can be + * certain that there are no databases left without checksums. + */ + DatabaseList = BuildDatabaseList(); + + /* + * If there are no databases at all to checksum, we can exit + * immediately as there is no work to do. This can probably never + * happen, but just in case. + */ + if (DatabaseList == NIL || list_length(DatabaseList) == 0) + return; + + processed_databases = 0; + + foreach(lc, DatabaseList) + { + ChecksumHelperDatabase *db = (ChecksumHelperDatabase *) lfirst(lc); + ChecksumHelperResult result; + Oid *oid; + + /* Skup if this database has been processed already */ + if (hash_search(ProcessedDatabases, (void *) &db->dboid, HASH_FIND, NULL)) + { + pfree(db->dbname); + pfree(db); + continue; + } + + result = ProcessDatabase(db); + + /* Make a copy of the oid so we can free the rest of the structure */ + oid = palloc(sizeof(Oid)); + *oid = db->dboid; + pfree(db->dbname); + pfree(db); + + hash_search(ProcessedDatabases, (void *) oid, HASH_ENTER, NULL); + processed_databases++; + + if (result == SUCCESSFUL) + { + /* + * If one database has completed shared catalogs, we don't + * have to process them again. + */ + if (ChecksumHelperShmem->process_shared_catalogs) + ChecksumHelperShmem->process_shared_catalogs = false; + } + else if (result == FAILED) + { + /* + * Put failed databases on the remaining list. + */ + FailedDatabases = lappend(FailedDatabases, db); + } + else + /* Abort flag set, so exit the whole process */ + return; + } + + elog(DEBUG1, "Completed one loop of checksum enabling, %i databases processed", processed_databases); + + list_free(DatabaseList); + + /* + * If no databases were processed in this run of the loop, we have now + * finished all databases and no concurrently created ones can exist. + */ + if (processed_databases == 0) + break; + } + + /* + * FailedDatabases now has all databases that failed one way or another. + * This can be because they actually failed for some reason, or because + * the database was dropped between us getting the database list and + * trying to process it. Get a fresh list of databases to detect the + * second case where the database was dropped before we had started + * processing it. If a database still exists, but enabling checksums + * failed then we fail the entire checksumming process and exit with an + * error. + */ + DatabaseList = BuildDatabaseList(); + + foreach(lc, FailedDatabases) + { + ChecksumHelperDatabase *db = (ChecksumHelperDatabase *) lfirst(lc); + bool found = false; + + foreach(lc2, DatabaseList) + { + ChecksumHelperDatabase *db2 = (ChecksumHelperDatabase *) lfirst(lc2); + + if (db->dboid == db2->dboid) + { + found = true; + ereport(WARNING, + (errmsg("failed to enable checksums in \"%s\"", + db->dbname))); + break; + } + } + + if (found) + found_failed = true; + else + { + ereport(LOG, + (errmsg("database \"%s\" has been dropped, skipping", + db->dbname))); + } + } + + if (found_failed) + { + /* Disable checksums on cluster, because we failed */ + SetDataChecksumsOff(); + ereport(ERROR, + (errmsg("checksumhelper failed to enable checksums in all databases, aborting"))); + } + + /* + * Force a checkpoint to get everything out to disk. XXX: this should + * probably not be an IMMEDIATE checkpoint, but leave it there for now for + * testing. + */ + RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_IMMEDIATE); + + /* + * Everything has been processed, so flag checksums enabled. + */ + SetDataChecksumsOn(); + + ereport(LOG, + (errmsg("checksums enabled, checksumhelper launcher shutting down"))); +} + +/* + * ChecksumHelperShmemSize + * Compute required space for checksumhelper-related shared memory + */ +Size +ChecksumHelperShmemSize(void) +{ + Size size; + + size = sizeof(ChecksumHelperShmemStruct); + size = MAXALIGN(size); + + return size; +} + +/* + * ChecksumHelperShmemInit + * Allocate and initialize checksumhelper-related shared memory + */ +void +ChecksumHelperShmemInit(void) +{ + bool found; + + ChecksumHelperShmem = (ChecksumHelperShmemStruct *) + ShmemInitStruct("ChecksumHelper Data", + ChecksumHelperShmemSize(), + &found); + + if (!found) + { + MemSet(ChecksumHelperShmem, 0, ChecksumHelperShmemSize()); + } +} + +/* + * BuildDatabaseList + * Compile a list of all currently available databases in the cluster + * + * This creates the list of databases for the checksumhelper workers to add + * checksums to. + */ +static List * +BuildDatabaseList(void) +{ + List *DatabaseList = NIL; + Relation rel; + TableScanDesc scan; + HeapTuple tup; + MemoryContext ctx = CurrentMemoryContext; + MemoryContext oldctx; + + StartTransactionCommand(); + + rel = table_open(DatabaseRelationId, AccessShareLock); + + /* + * Before we do this, wait for all pending transactions to finish. This + * will ensure there are no concurrently running CREATE DATABASE, which + * could cause us to miss the creation of a database that was copied + * without checksums. + */ + WaitForAllTransactionsToFinish(); + + scan = table_beginscan_catalog(rel, 0, NULL); + + while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection))) + { + Form_pg_database pgdb = (Form_pg_database) GETSTRUCT(tup); + ChecksumHelperDatabase *db; + + oldctx = MemoryContextSwitchTo(ctx); + + db = (ChecksumHelperDatabase *) palloc(sizeof(ChecksumHelperDatabase)); + + db->dboid = pgdb->oid; + db->dbname = pstrdup(NameStr(pgdb->datname)); + + DatabaseList = lappend(DatabaseList, db); + + MemoryContextSwitchTo(oldctx); + } + + table_endscan(scan); + table_close(rel, AccessShareLock); + + CommitTransactionCommand(); + + return DatabaseList; +} + +/* + * BuildRelationList + * Compile a list of all relations in the database + * + * If shared is true, both shared relations and local ones are returned, else + * all non-shared relations are returned. + * Temp tables are not included. + */ +static List * +BuildRelationList(bool include_shared) +{ + List *RelationList = NIL; + Relation rel; + TableScanDesc scan; + HeapTuple tup; + MemoryContext ctx = CurrentMemoryContext; + MemoryContext oldctx; + + StartTransactionCommand(); + + rel = table_open(RelationRelationId, AccessShareLock); + scan = table_beginscan_catalog(rel, 0, NULL); + + while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection))) + { + Form_pg_class pgc = (Form_pg_class) GETSTRUCT(tup); + ChecksumHelperRelation *relentry; + + if (pgc->relpersistence == 't') + continue; + + if (pgc->relisshared && !include_shared) + continue; + + /* + * Only include relations types that have local storage + */ + if (pgc->relkind == RELKIND_VIEW || + pgc->relkind == RELKIND_COMPOSITE_TYPE || + pgc->relkind == RELKIND_FOREIGN_TABLE) + continue; + + oldctx = MemoryContextSwitchTo(ctx); + relentry = (ChecksumHelperRelation *) palloc(sizeof(ChecksumHelperRelation)); + + relentry->reloid = pgc->oid; + relentry->relkind = pgc->relkind; + + RelationList = lappend(RelationList, relentry); + + MemoryContextSwitchTo(oldctx); + } + + table_endscan(scan); + table_close(rel, AccessShareLock); + + CommitTransactionCommand(); + + return RelationList; +} + +/* + * BuildTempTableList + * Compile a list of all temporary tables in database + * + * Returns a List of oids. + */ +static List * +BuildTempTableList(void) +{ + List *RelationList = NIL; + Relation rel; + TableScanDesc scan; + HeapTuple tup; + MemoryContext ctx = CurrentMemoryContext; + MemoryContext oldctx; + + StartTransactionCommand(); + + rel = table_open(RelationRelationId, AccessShareLock); + scan = table_beginscan_catalog(rel, 0, NULL); + + while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection))) + { + Form_pg_class pgc = (Form_pg_class) GETSTRUCT(tup); + + if (pgc->relpersistence != 't') + continue; + + oldctx = MemoryContextSwitchTo(ctx); + RelationList = lappend_oid(RelationList, pgc->oid); + MemoryContextSwitchTo(oldctx); + } + + table_endscan(scan); + table_close(rel, AccessShareLock); + + CommitTransactionCommand(); + + return RelationList; +} + +/* + * Main function for enabling checksums in a single database + */ +void +ChecksumHelperWorkerMain(Datum arg) +{ + Oid dboid = DatumGetObjectId(arg); + List *RelationList = NIL; + List *InitialTempTableList = NIL; + ListCell *lc; + BufferAccessStrategy strategy; + bool aborted = false; + + pqsignal(SIGTERM, die); + + BackgroundWorkerUnblockSignals(); + + init_ps_display(pgstat_get_backend_desc(B_CHECKSUMHELPER_WORKER), "", "", ""); + + ereport(DEBUG1, + (errmsg("checksum worker starting for database oid %d", dboid))); + + BackgroundWorkerInitializeConnectionByOid(dboid, InvalidOid, BGWORKER_BYPASS_ALLOWCONN); + + /* + * Get a list of all temp tables present as we start in this database. We + * need to wait until they are all gone until we are done, since we cannot + * access those files and modify them. + */ + InitialTempTableList = BuildTempTableList(); + + /* + * Enable vacuum cost delay, if any. + */ + VacuumCostDelay = ChecksumHelperShmem->cost_delay; + VacuumCostLimit = ChecksumHelperShmem->cost_limit; + VacuumCostActive = (VacuumCostDelay > 0); + VacuumCostBalance = 0; + VacuumPageHit = 0; + VacuumPageMiss = 0; + VacuumPageDirty = 0; + + /* + * Create and set the vacuum strategy as our buffer strategy. + */ + strategy = GetAccessStrategy(BAS_VACUUM); + + RelationList = BuildRelationList(ChecksumHelperShmem->process_shared_catalogs); + foreach(lc, RelationList) + { + ChecksumHelperRelation *rel = (ChecksumHelperRelation *) lfirst(lc); + + if (!ProcessSingleRelationByOid(rel->reloid, strategy)) + { + aborted = true; + break; + } + } + list_free_deep(RelationList); + + if (aborted) + { + ChecksumHelperShmem->success = ABORTED; + ereport(DEBUG1, + (errmsg("checksum worker aborted in database oid %d", dboid))); + return; + } + + /* + * Wait for all temp tables that existed when we started to go away. This + * is necessary since we cannot "reach" them to enable checksums. Any temp + * tables created after we started will already have checksums in them + * (due to the inprogress state), so those are safe. + */ + while (true) + { + List *CurrentTempTables; + ListCell *lc; + int numleft; + char activity[64]; + + CurrentTempTables = BuildTempTableList(); + numleft = 0; + foreach(lc, InitialTempTableList) + { + if (list_member_oid(CurrentTempTables, lfirst_oid(lc))) + numleft++; + } + list_free(CurrentTempTables); + + if (numleft == 0) + break; + + /* At least one temp table left to wait for */ + snprintf(activity, sizeof(activity), "Waiting for %d temp tables to be removed", numleft); + pgstat_report_activity(STATE_RUNNING, activity); + + /* Retry every 5 seconds */ + ResetLatch(MyLatch); + (void) WaitLatch(MyLatch, + WL_LATCH_SET | WL_TIMEOUT, + 5000, + WAIT_EVENT_PG_SLEEP); + } + + list_free(InitialTempTableList); + + ChecksumHelperShmem->success = SUCCESSFUL; + ereport(DEBUG1, + (errmsg("checksum worker completed in database oid %d", dboid))); +} diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c index 7410b2ff5e..0008879acc 100644 --- a/src/backend/postmaster/pgstat.c +++ b/src/backend/postmaster/pgstat.c @@ -4303,6 +4303,12 @@ pgstat_get_backend_desc(BackendType backendType) case B_WAL_WRITER: backendDesc = "walwriter"; break; + case B_CHECKSUMHELPER_LAUNCHER: + backendDesc = "checksumhelper launcher"; + break; + case B_CHECKSUMHELPER_WORKER: + backendDesc = "checksumhelper worker"; + break; } return backendDesc; diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c index 1fa4551eff..c18b0b4ecb 100644 --- a/src/backend/replication/basebackup.c +++ b/src/backend/replication/basebackup.c @@ -1397,7 +1397,7 @@ sendFile(const char *readfilename, const char *tarfilename, struct stat *statbuf _tarWriteHeader(tarfilename, NULL, statbuf, false); - if (!noverify_checksums && DataChecksumsEnabled()) + if (!noverify_checksums && DataChecksumsNeedVerify()) { char *filename; diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c index bc532d027b..5951f3250d 100644 --- a/src/backend/replication/logical/decode.c +++ b/src/backend/replication/logical/decode.c @@ -196,6 +196,7 @@ DecodeXLogOp(LogicalDecodingContext *ctx, XLogRecordBuffer *buf) case XLOG_FPW_CHANGE: case XLOG_FPI_FOR_HINT: case XLOG_FPI: + case XLOG_CHECKSUMS: break; default: elog(ERROR, "unexpected RM_XLOG_ID record type: %u", info); diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c index 4829953ee6..4a9822a19d 100644 --- a/src/backend/storage/ipc/ipci.c +++ b/src/backend/storage/ipc/ipci.c @@ -27,6 +27,7 @@ #include "postmaster/autovacuum.h" #include "postmaster/bgworker_internals.h" #include "postmaster/bgwriter.h" +#include "postmaster/checksumhelper.h" #include "postmaster/postmaster.h" #include "replication/logicallauncher.h" #include "replication/origin.h" @@ -255,6 +256,7 @@ CreateSharedMemoryAndSemaphores(void) WalSndShmemInit(); WalRcvShmemInit(); ApplyLauncherShmemInit(); + ChecksumHelperShmemInit(); /* * Set up other modules that need some shared memory space diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 9399ab0be4..96d257c9f6 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -456,8 +456,14 @@ ProcessProcSignalBarrier(void) * unconditionally, but it's more efficient to call only the ones that * might need us to do something based on the flags. */ - if (BARRIER_SHOULD_CHECK(flags, PROCSIGNAL_BARRIER_SAMPLE)) - ProcessBarrierSample(); + if (BARRIER_SHOULD_CHECK(flags, PROCSIGNAL_BARRIER_CHECKSUM)) + { + /* + * By virtue of getting here (i.e. interrupts being processed), we + * know that this backend won't have any in-progress writes (which + * might have missed the checksum change). + */ + } /* * State changes related to all types of barriers that might have been @@ -469,16 +475,6 @@ ProcessProcSignalBarrier(void) pg_atomic_write_u64(&MyProcSignalSlot->pss_barrierGeneration, generation); } -static void -ProcessBarrierSample(void) -{ - /* - * XXX. This should be something no-fail, which elog() is not, but this is - * just for testing purposes. - */ - elog(LOG, "ProcessBarrierSample"); -} - /* * CheckProcSignal - check to see if a particular reason has been * signaled, and clear the signal flag. Should be called after receiving diff --git a/src/backend/storage/lmgr/lwlocknames.txt b/src/backend/storage/lmgr/lwlocknames.txt index db47843229..d50b4b13e1 100644 --- a/src/backend/storage/lmgr/lwlocknames.txt +++ b/src/backend/storage/lmgr/lwlocknames.txt @@ -49,3 +49,4 @@ MultiXactTruncationLock 41 OldSnapshotTimeMapLock 42 LogicalRepWorkerLock 43 CLogTruncationLock 44 +ChecksumHelperLock 45 diff --git a/src/backend/storage/page/README b/src/backend/storage/page/README index 5127d98da3..f873fb0eea 100644 --- a/src/backend/storage/page/README +++ b/src/backend/storage/page/README @@ -9,7 +9,8 @@ have a very low measured incidence according to research on large server farms, http://www.cs.toronto.edu/~bianca/papers/sigmetrics09.pdf, discussed 2010/12/22 on -hackers list. -Current implementation requires this be enabled system-wide at initdb time. +Checksums can be enabled at initdb time, but can also be turned on and off +using pg_enable_data_checksums()/pg_disable_data_checksums() at runtime. The checksum is not valid at all times on a data page!! The checksum is valid when the page leaves the shared pool and is checked diff --git a/src/backend/storage/page/bufpage.c b/src/backend/storage/page/bufpage.c index 6b49810e37..6e3bfa045a 100644 --- a/src/backend/storage/page/bufpage.c +++ b/src/backend/storage/page/bufpage.c @@ -94,7 +94,7 @@ PageIsVerified(Page page, BlockNumber blkno) */ if (!PageIsNew(page)) { - if (DataChecksumsEnabled()) + if (DataChecksumsNeedVerify()) { checksum = pg_checksum_page((char *) page, blkno); @@ -1171,7 +1171,7 @@ PageSetChecksumCopy(Page page, BlockNumber blkno) static char *pageCopy = NULL; /* If we don't need a checksum, just return the passed-in data */ - if (PageIsNew(page) || !DataChecksumsEnabled()) + if (PageIsNew(page) || !DataChecksumsNeedWrite()) return (char *) page; /* @@ -1198,7 +1198,7 @@ void PageSetChecksumInplace(Page page, BlockNumber blkno) { /* If we don't need a checksum, just return */ - if (PageIsNew(page) || !DataChecksumsEnabled()) + if (PageIsNew(page) || !DataChecksumsNeedWrite()) return; ((PageHeader) page)->pd_checksum = pg_checksum_page((char *) page, blkno); diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 05240bfd14..61e856deac 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1527,7 +1527,7 @@ pg_stat_get_db_checksum_failures(PG_FUNCTION_ARGS) int64 result; PgStat_StatDBEntry *dbentry; - if (!DataChecksumsEnabled()) + if (!DataChecksumsNeedWrite()) PG_RETURN_NULL(); if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL) @@ -1545,7 +1545,7 @@ pg_stat_get_db_checksum_last_failure(PG_FUNCTION_ARGS) TimestampTz result; PgStat_StatDBEntry *dbentry; - if (!DataChecksumsEnabled()) + if (!DataChecksumsNeedWrite()) PG_RETURN_NULL(); if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL) diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 8d951ce404..7a8228be4b 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -33,6 +33,7 @@ #include "access/transam.h" #include "access/twophase.h" #include "access/xact.h" +#include "access/xlog.h" #include "access/xlog_internal.h" #include "catalog/namespace.h" #include "catalog/pg_authid.h" @@ -72,6 +73,7 @@ #include "replication/walreceiver.h" #include "replication/walsender.h" #include "storage/bufmgr.h" +#include "storage/checksum.h" #include "storage/dsm_impl.h" #include "storage/fd.h" #include "storage/large_object.h" @@ -473,6 +475,16 @@ static struct config_enum_entry shared_memory_options[] = { {NULL, 0, false} }; +/* + * Options for data_checksums enum. + */ +static const struct config_enum_entry data_checksum_options[] = { + {"on", DATA_CHECKSUMS_ON, true}, + {"off", DATA_CHECKSUMS_OFF, true}, + {"inprogress", DATA_CHECKSUMS_INPROGRESS, true}, + {NULL, 0, false} +}; + /* * Options for enum values stored in other modules */ @@ -580,7 +592,7 @@ static int max_identifier_length; static int block_size; static int segment_size; static int wal_block_size; -static bool data_checksums; +static int data_checksums_tmp; static bool integer_datetimes; static bool assert_enabled; static char *recovery_target_timeline_string; @@ -1840,17 +1852,6 @@ static struct config_bool ConfigureNamesBool[] = NULL, NULL, NULL }, - { - {"data_checksums", PGC_INTERNAL, PRESET_OPTIONS, - gettext_noop("Shows whether data checksums are turned on for this cluster."), - NULL, - GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE - }, - &data_checksums, - false, - NULL, NULL, NULL - }, - { {"syslog_sequence_numbers", PGC_SIGHUP, LOGGING_WHERE, gettext_noop("Add sequence number to syslog messages to avoid duplicate suppression."), @@ -4600,6 +4601,17 @@ static struct config_enum ConfigureNamesEnum[] = NULL, NULL, NULL }, + { + {"data_checksums", PGC_INTERNAL, PRESET_OPTIONS, + gettext_noop("Shows whether data checksums are turned on for this cluster."), + NULL, + GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE + }, + &data_checksums_tmp, + DATA_CHECKSUMS_OFF, data_checksum_options, + NULL, NULL, show_data_checksums + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL, NULL diff --git a/src/bin/pg_upgrade/controldata.c b/src/bin/pg_upgrade/controldata.c index 93f3c34b74..4fed2450fc 100644 --- a/src/bin/pg_upgrade/controldata.c +++ b/src/bin/pg_upgrade/controldata.c @@ -657,6 +657,15 @@ check_control_data(ControlData *oldctrl, * check_for_isn_and_int8_passing_mismatch(). */ + /* + * If checksums have been turned on in the old cluster, but the + * checksumhelper have yet to finish, then disallow upgrading. The user + * should either let the process finish, or turn off checksums, before + * retrying. + */ + if (oldctrl->data_checksum_version == 2) + pg_fatal("checksum enabling in old cluster is in progress\n"); + /* * We might eventually allow upgrades from checksum to no-checksum * clusters. diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h index 729f86aa32..97fc7b4de7 100644 --- a/src/bin/pg_upgrade/pg_upgrade.h +++ b/src/bin/pg_upgrade/pg_upgrade.h @@ -220,7 +220,7 @@ typedef struct uint32 large_object; bool date_is_int; bool float8_pass_by_value; - bool data_checksum_version; + uint32 data_checksum_version; } ControlData; /* diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index 9b588c87a5..dda9c9abad 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -189,7 +189,7 @@ extern PGDLLIMPORT int wal_level; * of the bits make it to disk, but the checksum wouldn't match. Also WAL-log * them if forced by wal_log_hints=on. */ -#define XLogHintBitIsNeeded() (DataChecksumsEnabled() || wal_log_hints) +#define XLogHintBitIsNeeded() (DataChecksumsNeedWrite() || wal_log_hints) /* Do we need to WAL-log information required only for Hot Standby and logical replication? */ #define XLogStandbyInfoActive() (wal_level >= WAL_LEVEL_REPLICA) @@ -292,7 +292,13 @@ extern TimestampTz GetCurrentChunkReplayStartTime(void); extern void UpdateControlFile(void); extern uint64 GetSystemIdentifier(void); extern char *GetMockAuthenticationNonce(void); -extern bool DataChecksumsEnabled(void); +extern bool DataChecksumsNeedWrite(void); +extern bool DataChecksumsNeedVerify(void); +extern bool DataChecksumsInProgress(void); +extern void SetDataChecksumsInProgress(void); +extern void SetDataChecksumsOn(void); +extern void SetDataChecksumsOff(void); +extern const char *show_data_checksums(void); extern XLogRecPtr GetFakeLSNForUnloggedRel(void); extern Size XLOGShmemSize(void); extern void XLOGShmemInit(void); diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h index e295dc65fb..a588cb7ed9 100644 --- a/src/include/access/xlog_internal.h +++ b/src/include/access/xlog_internal.h @@ -25,6 +25,7 @@ #include "lib/stringinfo.h" #include "pgtime.h" #include "storage/block.h" +#include "storage/checksum.h" #include "storage/relfilenode.h" @@ -245,6 +246,12 @@ typedef struct xl_restore_point char rp_name[MAXFNAMELEN]; } xl_restore_point; +/* Information logged when checksum level is changed */ +typedef struct xl_checksum_state +{ + ChecksumType new_checksumtype; +} xl_checksum_state; + /* End of recovery mark, when we don't do an END_OF_RECOVERY checkpoint */ typedef struct xl_end_of_recovery { diff --git a/src/include/catalog/pg_control.h b/src/include/catalog/pg_control.h index cf7d4485e9..c79b3fa365 100644 --- a/src/include/catalog/pg_control.h +++ b/src/include/catalog/pg_control.h @@ -76,6 +76,7 @@ typedef struct CheckPoint #define XLOG_END_OF_RECOVERY 0x90 #define XLOG_FPI_FOR_HINT 0xA0 #define XLOG_FPI 0xB0 +#define XLOG_CHECKSUMS 0xC0 /* diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index ac8f64b219..5ea54f968d 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -10663,6 +10663,22 @@ proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}', prosrc => 'pg_control_init' }, +{ oid => '4142', + descr => 'disable data checksums', + proname => 'pg_disable_data_checksums', provolatile => 'v', prorettype => 'bool', + proparallel => 'r', + proargtypes => '', + prosrc => 'disable_data_checksums' }, + +{ oid => '4035', + descr => 'enable data checksums', + proname => 'pg_enable_data_checksums', provolatile => 'v', prorettype => 'void', + proparallel => 'r', + proargtypes => 'int4 int4', proallargtypes => '{int4,int4}', + proargmodes => '{i,i}', + proargnames => '{cost_delay,cost_limit}', + prosrc => 'enable_data_checksums' }, + # collation management functions { oid => '3445', descr => 'import collations from operating system', proname => 'pg_import_system_collations', procost => '100', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index f2e873d048..8704b68de8 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -727,7 +727,9 @@ typedef enum BackendType B_STARTUP, B_WAL_RECEIVER, B_WAL_SENDER, - B_WAL_WRITER + B_WAL_WRITER, + B_CHECKSUMHELPER_LAUNCHER, + B_CHECKSUMHELPER_WORKER } BackendType; diff --git a/src/include/postmaster/checksumhelper.h b/src/include/postmaster/checksumhelper.h new file mode 100644 index 0000000000..556f801668 --- /dev/null +++ b/src/include/postmaster/checksumhelper.h @@ -0,0 +1,31 @@ +/*------------------------------------------------------------------------- + * + * checksumhelper.h + * header file for checksum helper background worker + * + * + * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/postmaster/checksumhelper.h + * + *------------------------------------------------------------------------- + */ +#ifndef CHECKSUMHELPER_H +#define CHECKSUMHELPER_H + +/* Shared memory */ +extern Size ChecksumHelperShmemSize(void); +extern void ChecksumHelperShmemInit(void); + +/* Start the background processes for enabling checksums */ +void StartChecksumHelperLauncher(int cost_delay, int cost_limit); + +/* Shutdown the background processes, if any */ +void ShutdownChecksumHelperIfRunning(void); + +/* Background worker entrypoints */ +void ChecksumHelperLauncherMain(Datum arg); +void ChecksumHelperWorkerMain(Datum arg); + +#endif /* CHECKSUMHELPER_H */ diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h index 4ef6d8ddd4..cf31f24b01 100644 --- a/src/include/storage/bufpage.h +++ b/src/include/storage/bufpage.h @@ -198,6 +198,7 @@ typedef PageHeaderData *PageHeader; */ #define PG_PAGE_LAYOUT_VERSION 4 #define PG_DATA_CHECKSUM_VERSION 1 +#define PG_DATA_CHECKSUM_INPROGRESS_VERSION 2 /* ---------------------------------------------------------------- * page support macros diff --git a/src/include/storage/checksum.h b/src/include/storage/checksum.h index 7ef32a3baa..2c414aa1e7 100644 --- a/src/include/storage/checksum.h +++ b/src/include/storage/checksum.h @@ -15,6 +15,13 @@ #include "storage/block.h" +typedef enum ChecksumType +{ + DATA_CHECKSUMS_OFF = 0, + DATA_CHECKSUMS_ON, + DATA_CHECKSUMS_INPROGRESS +} ChecksumType; + /* * Compute the checksum for a Postgres page. The page must be aligned on a * 4-byte boundary. diff --git a/src/include/storage/procsignal.h b/src/include/storage/procsignal.h index 90eda29d15..02e22f38f5 100644 --- a/src/include/storage/procsignal.h +++ b/src/include/storage/procsignal.h @@ -47,7 +47,7 @@ typedef enum typedef enum { - PROCSIGNAL_BARRIER_SAMPLE = 0 + PROCSIGNAL_BARRIER_CHECKSUM = 0 } ProcSignalBarrierType; /* diff --git a/src/test/Makefile b/src/test/Makefile index efb206aa75..6469ac94a4 100644 --- a/src/test/Makefile +++ b/src/test/Makefile @@ -12,7 +12,8 @@ subdir = src/test top_builddir = ../.. include $(top_builddir)/src/Makefile.global -SUBDIRS = perl regress isolation modules authentication recovery subscription +SUBDIRS = perl regress isolation modules authentication recovery subscription \ + checksum # Test suites that are not safe by default but can be run if selected # by the user via the whitespace-separated list in variable diff --git a/src/test/checksum/.gitignore b/src/test/checksum/.gitignore new file mode 100644 index 0000000000..871e943d50 --- /dev/null +++ b/src/test/checksum/.gitignore @@ -0,0 +1,2 @@ +# Generated by test suite +/tmp_check/ diff --git a/src/test/checksum/Makefile b/src/test/checksum/Makefile new file mode 100644 index 0000000000..22a3b64dd8 --- /dev/null +++ b/src/test/checksum/Makefile @@ -0,0 +1,24 @@ +#------------------------------------------------------------------------- +# +# Makefile for src/test/checksum +# +# Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group +# Portions Copyright (c) 1994, Regents of the University of California +# +# src/test/checksum/Makefile +# +#------------------------------------------------------------------------- + +subdir = src/test/checksum +top_builddir = ../../.. +include $(top_builddir)/src/Makefile.global + +check: + $(prove_check) + +installcheck: + $(prove_installcheck) + +clean distclean maintainer-clean: + rm -rf tmp_check + diff --git a/src/test/checksum/README b/src/test/checksum/README new file mode 100644 index 0000000000..e3fbd2bdb5 --- /dev/null +++ b/src/test/checksum/README @@ -0,0 +1,22 @@ +src/test/checksum/README + +Regression tests for data checksums +=================================== + +This directory contains a test suite for enabling data checksums +in a running cluster with streaming replication. + +Running the tests +================= + + make check + +or + + make installcheck + +NOTE: This creates a temporary installation (in the case of "check"), +with multiple nodes, be they master or standby(s) for the purpose of +the tests. + +NOTE: This requires the --enable-tap-tests argument to configure. diff --git a/src/test/checksum/t/001_standby_checksum.pl b/src/test/checksum/t/001_standby_checksum.pl new file mode 100644 index 0000000000..891743fa6c --- /dev/null +++ b/src/test/checksum/t/001_standby_checksum.pl @@ -0,0 +1,104 @@ +# Test suite for testing enabling data checksums with streaming replication +use strict; +use warnings; +use PostgresNode; +use TestLib; +use Test::More tests => 10; + +my $MAX_TRIES = 30; + +# Initialize master node +my $node_master = get_new_node('master'); +$node_master->init(allows_streaming => 1); +$node_master->start; +my $backup_name = 'my_backup'; + +# Take backup +$node_master->backup($backup_name); + +# Create streaming standby linking to master +my $node_standby_1 = get_new_node('standby_1'); +$node_standby_1->init_from_backup($node_master, $backup_name, + has_streaming => 1); +$node_standby_1->start; + +# Create some content on master to have un-checksummed data in the cluster +$node_master->safe_psql('postgres', + "CREATE TABLE t AS SELECT generate_series(1,10000) AS a;"); + +# Wait for standbys to catch up +$node_master->wait_for_catchup($node_standby_1, 'replay', + $node_master->lsn('insert')); + +# Check that checksums are turned off +my $result = $node_master->safe_psql('postgres', + "SELECT setting FROM pg_catalog.pg_settings WHERE name = 'data_checksums';"); +is($result, "off", 'ensure checksums are turned off on master'); + +$result = $node_standby_1->safe_psql('postgres', + "SELECT setting FROM pg_catalog.pg_settings WHERE name = 'data_checksums';"); +is($result, "off", 'ensure checksums are turned off on standby_1'); + +# Enable checksums for the cluster +$node_master->safe_psql('postgres', "SELECT pg_enable_data_checksums();"); + +# Ensure that the master has switched to inprogress immediately +$result = $node_master->safe_psql('postgres', + "SELECT setting FROM pg_catalog.pg_settings WHERE name = 'data_checksums';"); +is($result, "inprogress", 'ensure checksums are in progress on master'); + +# Wait for checksum enable to be replayed +$node_master->wait_for_catchup($node_standby_1, 'replay'); + +# Ensure that the standby has switched to inprogress or on +# Normally it would be "inprogress", but it is theoretically possible for the master +# to complete the checksum enabling *and* have the standby replay that record before +# we reach the check below. +$result = $node_standby_1->safe_psql('postgres', + "SELECT setting FROM pg_catalog.pg_settings WHERE name = 'data_checksums';"); +cmp_ok($result, '~~', ["inprogress", "on"], 'ensure checksums are on or in progress on standby_1'); + +# Insert some more data which should be checksummed on INSERT +$node_master->safe_psql('postgres', + "INSERT INTO t VALUES (generate_series(1,10000));"); + +# Wait for checksums enabled on the master +for (my $i = 0; $i < $MAX_TRIES; $i++) +{ + $result = $node_master->safe_psql('postgres', + "SELECT setting FROM pg_catalog.pg_settings WHERE name = 'data_checksums';"); + last if ($result eq 'on'); + sleep(1); +} +is ($result, "on", 'ensure checksums are enabled on master'); + +# Wait for checksums enabled on the standby +for (my $i = 0; $i < $MAX_TRIES; $i++) +{ + $result = $node_standby_1->safe_psql('postgres', + "SELECT setting FROM pg_catalog.pg_settings WHERE name = 'data_checksums';"); + last if ($result eq 'on'); + sleep(1); +} +is ($result, "on", 'ensure checksums are enabled on standby'); + +$result = $node_master->safe_psql('postgres', "SELECT count(a) FROM t"); +is ($result, "20000", 'ensure we can safely read all data with checksums'); + +# Disable checksums and ensure it's propagated to standby and that we can +# still read all data +$node_master->safe_psql('postgres', "SELECT pg_disable_data_checksums();"); +$result = $node_master->safe_psql('postgres', + "SELECT setting FROM pg_catalog.pg_settings WHERE name = 'data_checksums';"); +is($result, "off", 'ensure checksums are off on master'); + +# Wait for checksum disable to be replayed +$node_master->wait_for_catchup($node_standby_1, 'replay'); + +# Ensure that the standby has switched to off +$result = $node_standby_1->safe_psql('postgres', + "SELECT setting FROM pg_catalog.pg_settings WHERE name = 'data_checksums';"); +is($result, "off", 'ensure checksums are off on standby_1'); + +$result = $node_master->safe_psql('postgres', "SELECT count(a) FROM t"); +is ($result, "20000", 'ensure we can safely read all data without checksums'); -- 2.21.0 (Apple Git-122.2)