From b7787a7d1e6ec6f8211efccdefc7de0340b4a472 Mon Sep 17 00:00:00 2001 From: Julien Rouhaud Date: Mon, 4 Nov 2019 08:40:23 +0100 Subject: [PATCH v6] Add a pg_check_relation() function. This functions checks the validity of the checksums for all non-dirty blocks of a given relation, and optionally a given fork, and returns the list of all blocks that don't match, along with the expected and found checksums. Author: Julien Rouhaud Reviewed-by: Michael Paquier, Masahiko Sawada Discussion: https://postgr.es/m/CAOBaU_aVvMjQn%3Dge5qPiJOPMmOj5%3Dii3st5Q0Y%2BWuLML5sR17w%40mail.gmail.com --- doc/src/sgml/config.sgml | 85 ++++ doc/src/sgml/func.sgml | 51 +++ src/backend/catalog/system_views.sql | 7 + src/backend/storage/page/checksum.c | 424 +++++++++++++++++- src/backend/utils/adt/Makefile | 1 + src/backend/utils/adt/checksumfuncs.c | 96 ++++ src/backend/utils/init/globals.c | 7 + src/backend/utils/misc/guc.c | 33 ++ src/backend/utils/misc/postgresql.conf.sample | 6 + src/include/catalog/pg_proc.dat | 8 + src/include/miscadmin.h | 7 + src/include/storage/checksum.h | 7 + src/include/utils/guc_tables.h | 1 + src/test/Makefile | 3 +- src/test/check_relation/.gitignore | 2 + src/test/check_relation/Makefile | 23 + src/test/check_relation/README | 23 + .../check_relation/t/01_checksums_check.pl | 276 ++++++++++++ 18 files changed, 1056 insertions(+), 4 deletions(-) create mode 100644 src/backend/utils/adt/checksumfuncs.c create mode 100644 src/test/check_relation/.gitignore create mode 100644 src/test/check_relation/Makefile create mode 100644 src/test/check_relation/README create mode 100644 src/test/check_relation/t/01_checksums_check.pl diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 2de21903a1..377ca700b0 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -2043,6 +2043,91 @@ include_dir 'conf.d' + + + + + During the execution of + function, the system maintains an internal counter that keeps track of + the estimated cost of the various I/O operations that are performed. + When the accumulated cost reaches a limit (specified by + checksum_cost_limit), the process performing the + operation will sleep for a short period of time, as specified by + checksum_cost_delay. Then it will reset the counter + and continue execution. + + + + This feature is disabled by default. To enable it, set the + checksum_cost_delay variable to a nonzero + value. + + + + + checksum_cost_delay (floating point) + + checksum_cost_delay configuration parameter + + + + + The amount of time that the process will sleep + when the cost limit has been exceeded. + If this value is specified without units, it is taken as milliseconds. + The default value is zero, which disables the cost-based checksum + verification delay feature. Positive values enable cost-based + checksum verification. + + + + + + checksum_cost_page (integer) + + checksum_cost_page configuration parameter + + + + + The estimated cost for verifying a buffer, whether it's found in the + shared buffer cache or not. It represents the cost to lock the buffer + pool, lookup the shared hash table, read the content of the page from + disk and compute its checksum. The default value is 10. + + + + + + checksum_cost_limit (integer) + + checksum_cost_limit configuration parameter + + + + + The accumulated cost that will cause the verification process to sleep. + The default value is 200. + + + + + + + + There are certain operations that hold critical locks and should + therefore complete as quickly as possible. Cost-based checksum + verification delays do not occur during such operations. Therefore it + is possible that the cost accumulates far higher than the specified + limit. To avoid uselessly long delays in such cases, the actual delay + is calculated as checksum_cost_delay * + accumulated_balance / + checksum_cost_limit with a maximum of + checksum_cost_delay * 4. + + + + diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7a0bb0c70a..1187ea6b98 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21849,6 +21849,57 @@ SELECT (pg_stat_file('filename')).modification; + + + + + The functions shown in + provide means to check for health of data file in a cluster. + + + + + + + Name Return Type Description + + + + + + + pg_check_relation(relation oid[, fork text]) + + setof record + Validate the checksums for all blocks of a given relation, and + optionally the given fork. + + + + + + + pg_check_relation + + + pg_check_relation iterates over all the blocks of a + given relation and verify their checksum. If provided, + fork should be 'main' for the + main data fork, 'fsm' for the free space map, + 'vm' for the visibility map, or + 'init' for the initialization fork, and only this + specific fork will be verifies, otherwise all forks will. The function + returns the list of blocks for which the found checksum doesn't match the + expected one. See for + information on how to configure cost-based verification delay. You must be + a member of the pg_read_all_stats role to use this + function. It can only be used if data checksums are enabled. See for more information. + + + + diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 83d00c6cde..071aa5aa2b 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -1387,6 +1387,13 @@ LANGUAGE INTERNAL STRICT STABLE PARALLEL SAFE AS 'jsonb_path_query_first_tz'; +CREATE OR REPLACE FUNCTION pg_check_relation( + IN relation regclass, IN fork text DEFAULT NULL::text, + OUT relid oid, OUT forknum integer, OUT failed_blocknum bigint, + OUT expected_checksum integer, OUT found_checksum integer) + RETURNS SETOF record VOLATILE LANGUAGE internal AS 'pg_check_relation' + PARALLEL RESTRICTED; + -- -- The default permissions for functions mean that anyone can execute them. -- A number of functions shouldn't be executable by just anyone, but rather diff --git a/src/backend/storage/page/checksum.c b/src/backend/storage/page/checksum.c index e010691c9f..09d453afa6 100644 --- a/src/backend/storage/page/checksum.c +++ b/src/backend/storage/page/checksum.c @@ -15,8 +15,426 @@ #include "storage/checksum.h" /* - * The actual code is in storage/checksum_impl.h. This is done so that - * external programs can incorporate the checksum code by #include'ing - * that file from the exported Postgres headers. (Compare our CRC code.) + * The actual checksum computation code is in storage/checksum_impl.h. This + * is done so that external programs can incorporate the checksum code by + * #include'ing that file from the exported Postgres headers. (Compare our + * CRC code.) */ #include "storage/checksum_impl.h" + +#include "access/heapam.h" +#include "access/htup_details.h" +#include "catalog/pg_authid_d.h" +#include "commands/dbcommands.h" +#include "funcapi.h" +#include "miscadmin.h" +#include "pgstat.h" +#include "storage/buf_internals.h" +#include "storage/checksum.h" +#include "storage/lockdefs.h" +#include "utils/acl.h" +#include "utils/builtins.h" +#include "utils/guc.h" +#include "utils/lsyscache.h" +#include "utils/rel.h" +#include "utils/syscache.h" + +/* + * A zero checksum can never be computed, see pg_checksum_page() */ +#define NoComputedChecksum 0 + +/* ---------------- + * The rest of this module provides a set of functions that can be used to + * safely check all checksums on a running cluster. + * + * Please note that those only perform standard buffered reads, and don't try + * to bypass or discard the operating system cache. If you want to check the + * actual storage, you have to discard the operating system cache before + * running those functions. + * + * To avoid torn page and possible false positive when reading data, and + * keeping overhead as low as possible, the following heuristics are used: + * + * - a shared LWLock is taken on the target buffer pool partition mapping, and + * we detect if a block is in shared_buffers or not. See check_get_buffer() + * comments for more details about the locking strategy. + * + * - if a block is dirty in shared_buffers, it's ignored as it'll be flushed to + * disk either before the end of the next checkpoint or during recovery in + * case of unsafe shutdown + * + * - if a block is otherwise found in shared_buffers, an IO lock is taken on + * the block and the block is then read from storage, ignoring the block in + * shared_buffers + * + * - if a block is not found in shared_buffers, the LWLock is released and the + * block is read from disk without taking any lock. If an error is detected, + * the read block will be discarded and retrieved again while holding the + * LWLock. This is because an error due to concurrent write is possible but + * very unlikely, so it's better to have an optimistic approach to limit + * locking overhead + * + * The check can be performed using an SQL function, returning the list of + * problematic blocks. + * ---------------- + */ + +static bool check_buffer(char *buffer, uint32 blkno, uint16 *chk_expected, + uint16 *chk_found); +static void check_relation_fork(TupleDesc tupdesc, Tuplestorestate *tupstore, + Relation relation, ForkNumber forknum); +static void check_delay_point(void); +static bool check_get_buffer(Relation relation, ForkNumber forknum, + BlockNumber blkno, char *buffer, bool needlock, + bool *found_in_sb); + +/* + * Perform a checksum check on the passed page. Returns whether the page is + * valid or not, and assign the expected and found checksum in chk_expected and + * chk_found, respectively. Note that a page can look like new but could be + * the result of a corruption. We still check for this case, but we can't + * compute its checksum as pg_checksum_page() is explicitly checking for non-new + * pages, so NoComputedChecksum will be set in chk_found. + */ +static bool +check_buffer(char *buffer, uint32 blkno, uint16 *chk_expected, + uint16 *chk_found) +{ + PageHeader hdr = (PageHeader) buffer; + + Assert(chk_expected && chk_found); + + if (PageIsNew(hdr)) + { + /* + * Check if the page is really new or if there's a corruption that + * affected PageIsNew detection. Note that PageIsVerified won't try to + * detect checksum corruption in this case, so there's no risk of + * duplicated corruption report. + */ + if (PageIsVerified(buffer, blkno)) + { + /* No corruption. */ + *chk_expected = *chk_found = NoComputedChecksum; + return true; + } + else + { + /* + * There's a corruption, but since this affect PageIsNew, we + * can't compute a checksum, so set NoComputedChecksum for the + * expected checksum. + */ + *chk_expected = NoComputedChecksum; + *chk_found = hdr->pd_checksum; + } + return false; + } + + *chk_expected = pg_checksum_page(buffer, blkno); + *chk_found = hdr->pd_checksum; + + return (*chk_expected == *chk_found); +} + +/* + * Perform the check on a single relation, possibly filtered with a single + * fork. This function will check if the given relation exists or not, as + * a relation could be dropped after checking for the list of relations and + * before getting here, and we don't want to error out in this case. + */ +void +check_one_relation(TupleDesc tupdesc, Tuplestorestate *tupstore, + Oid relid, ForkNumber single_forknum) +{ + Relation relation = NULL; + ForkNumber forknum; + + /* Open the relation if it exists. */ + if (SearchSysCacheExists1(RELOID, ObjectIdGetDatum(relid))) + { + relation = relation_open(relid, AccessShareLock); + } + + /* sanity checks */ + if (!RelationIsValid(relation)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_TABLE), + errmsg("could not open relation with OID %u", relid))); + + if (!RELKIND_HAS_STORAGE(relation->rd_rel->relkind)) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("relation \"%s\" does not have storage to be checked", + quote_qualified_identifier( + get_namespace_name(get_rel_namespace(relid)), + get_rel_name(relid))))); + + if (RELATION_IS_OTHER_TEMP(relation)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot verify temporary tables of other sessions"))); + + RelationOpenSmgr(relation); + + for (forknum = 0; forknum <= MAX_FORKNUM; forknum++) + { + if (single_forknum != InvalidForkNumber && single_forknum != forknum) + continue; + + if (smgrexists(relation->rd_smgr, forknum)) + check_relation_fork(tupdesc, tupstore, relation, forknum); + } + + relation_close(relation, AccessShareLock); /* release the lock */ +} + +/* + * For a given relation and fork, Do the real work of iterating over all pages + * and doing the check. Caller must hold an AccessShareLock lock on the given + * relation. + */ +static void +check_relation_fork(TupleDesc tupdesc, Tuplestorestate *tupstore, + Relation relation, ForkNumber forknum) +{ + BlockNumber blkno, + nblocks; + char buffer[BLCKSZ]; + bool found_in_sb; + + /* + * We remember the number of blocks here. Since caller must hold a lock on + * the relation, we know that it won't be truncated while we're iterating + * over the blocks. Any block added after this function started won't be + * checked, but this is out of scope as such pages will be flushed before + * the next checkpoint's completion. + */ + nblocks = RelationGetNumberOfBlocksInFork(relation, forknum); + +#define SRF_COLS 5 /* Number of output arguments in the SRF */ + for (blkno = 0; blkno < nblocks; blkno++) + { + bool force_lock = false; + uint16 chk_expected, + chk_found; + Datum values[SRF_COLS]; + bool nulls[SRF_COLS]; + int i = 0; + + memset(values, 0, sizeof(values)); + memset(nulls, 0, sizeof(nulls)); + + /* + * To avoid too much overhead, the buffer will be first read without + * the locks that would guarantee the lack of false positive, as such + * events should be quite rare. + */ +Retry: + if (!check_get_buffer(relation, forknum, blkno, buffer, force_lock, + &found_in_sb)) + continue; + + if (check_buffer(buffer, blkno, &chk_expected, &chk_found)) + continue; + + /* + * If we get a failure and the buffer wasn't found in shared buffers, + * reread the buffer with suitable lock to avoid false positive. See + * check_get_buffer for more details. + */ + if (!found_in_sb && !force_lock) + { + force_lock = true; + goto Retry; + } + + values[i++] = ObjectIdGetDatum(relation->rd_id); + values[i++] = Int32GetDatum(forknum); + values[i++] = UInt32GetDatum(blkno); + /* + * This can happen if a corruption makes the block appears as + * PageIsNew() but isn't a new page. + */ + if (chk_expected == NoComputedChecksum) + nulls[i++] = true; + else + values[i++] = UInt16GetDatum(chk_expected); + values[i++] = UInt16GetDatum(chk_found); + + Assert(i == SRF_COLS); + + /* Report the failure to the stat collector and the logs. */ + pgstat_report_checksum_failure(); + ereport(WARNING, + (errcode(ERRCODE_DATA_CORRUPTED), + errmsg("invalid page in block %u of relation %s", + blkno, + relpath(relation->rd_smgr->smgr_rnode, forknum)))); + + /* Save the corrupted blocks in the tuplestore. */ + tuplestore_putvalues(tupstore, tupdesc, values, nulls); + } +} + +/* + * Check for interrupts and cost-based delay. + */ +static void +check_delay_point(void) +{ + /* Always check for interrupts */ + CHECK_FOR_INTERRUPTS(); + + if (!ChecksumCostActive || InterruptPending) + return; + + /* Nap if appropriate */ + if (ChecksumCostBalance >= ChecksumCostLimit) + { + int msec; + + msec = ChecksumCostDelay * ChecksumCostBalance / ChecksumCostLimit; + if (msec > ChecksumCostDelay * 4) + msec = ChecksumCostDelay * 4; + + pg_usleep(msec * 1000L); + + ChecksumCostBalance = 0; + + /* Might have gotten an interrupt while sleeping */ + CHECK_FOR_INTERRUPTS(); + } +} + +/* + *------------------------- + * Safely read the wanted buffer from disk, dealing with possible concurrency + * issue. Note that if a buffer is found dirty in shared_buffers, no read will + * be performed and the caller will be informed that no check should be done. + * We can safely ignore such buffers as they'll be written before next + * checkpoint's completion.. + * + * The following locks can be used in this function: + * + * - shared LWLock on the target buffer pool partition mapping. + * - IOLock on the buffer + * + * The IOLock is taken when reading the buffer from disk if it exists in + * shared_buffers, to avoid torn pages. + * + * If the buffer isn't in shared_buffers, it'll be read from disk without any + * lock unless caller asked otherwise, setting needlock. In this case, the + * read will be done while the buffer mapping partition LWLock is still being + * held. Reading with this lock is to avoid the unlikely but possible case + * that a buffer wasn't present in shared buffers when we checked but it then + * alloc'ed in shared_buffers, modified and flushed concurrently when we + * later try to read it, leading to false positive due to torn page. Caller + * can read first the buffer without holding the target buffer mapping + * partition LWLock to have an optimistic approach, and reread the buffer + * from disk in case of error. + * + * Caller should hold an AccessShareLock on the Relation + *------------------------- + */ +static bool +check_get_buffer(Relation relation, ForkNumber forknum, + BlockNumber blkno, char *buffer, bool needlock, + bool *found_in_sb) +{ + bool checkit = true; + BufferTag buf_tag; /* identity of requested block */ + uint32 buf_hash; /* hash value for buf_tag */ + LWLock *partLock; /* buffer partition lock for the buffer */ + BufferDesc *bufdesc; + int buf_id; + + *found_in_sb = false; + + /* Check for interrupts and take throttling into account. */ + check_delay_point(); + + /* create a tag so we can lookup the buffer */ + INIT_BUFFERTAG(buf_tag, relation->rd_smgr->smgr_rnode.node, forknum, blkno); + + /* determine its hash code and partition lock ID */ + buf_hash = BufTableHashCode(&buf_tag); + partLock = BufMappingPartitionLock(buf_hash); + + /* see if the block is in the buffer pool already */ + LWLockAcquire(partLock, LW_SHARED); + buf_id = BufTableLookup(&buf_tag, buf_hash); + if (buf_id >= 0) + { + uint32 buf_state; + + *found_in_sb = true; + + /* + * Found it. Now, retrieve its state to know what to do with it, and + * release the pin immediately. We do so to limit overhead as much + * as possible. We'll keep the shared lightweight lock on the target + * buffer mapping partition, so this buffer can't be evicted, and + * we'll acquire an IOLock on the buffer if we need to read the + * content on disk. + */ + bufdesc = GetBufferDescriptor(buf_id); + + buf_state = LockBufHdr(bufdesc); + UnlockBufHdr(bufdesc, buf_state); + + /* Dirty pages are ignored as they'll be flushed soon. */ + if (buf_state & BM_DIRTY) + checkit = false; + + /* + * Read the buffer from disk, taking on IO lock to prevent torn-page + * reads, in the unlikely event that it was concurrently dirtied and + * flushed. + */ + if (checkit) + { + LWLockAcquire(BufferDescriptorGetIOLock(bufdesc), LW_SHARED); + smgrread(relation->rd_smgr, forknum, blkno, buffer); + LWLockRelease(BufferDescriptorGetIOLock(bufdesc)); + + /* Add a page cost. */ + ChecksumCostBalance += ChecksumCostPage; + } + } + else if (needlock) + { + /* + * Caller asked to read the buffer while we have a lock on the target + * partition. + */ + smgrread(relation->rd_smgr, forknum, blkno, buffer); + + /* + * Add a page miss cost, as we're always reading outside the shared + * buffers. + */ + /* Add a page cost. */ + ChecksumCostBalance += ChecksumCostPage; + } + + LWLockRelease(partLock); + + if (*found_in_sb || needlock) + return checkit; + + /* + * Didn't find it in the buffer pool and didn't read it while holding the + * buffer mapping partition lock. We'll have to try to read it from + * disk, after releasing the target partition lock to avoid too much + * overhead. It means that it's possible to get a torn page later, so + * we'll have to retry with a suitable lock in case of error to avoid + * false positive. + */ + smgrread(relation->rd_smgr, forknum, blkno, buffer); + + /* Add a page cost. */ + ChecksumCostBalance += ChecksumCostPage; + + return checkit; +} diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile index 13efa9338c..27dc524e00 100644 --- a/src/backend/utils/adt/Makefile +++ b/src/backend/utils/adt/Makefile @@ -22,6 +22,7 @@ OBJS = \ bool.o \ cash.o \ char.o \ + checksumfuncs.o \ cryptohashes.o \ date.o \ datetime.o \ diff --git a/src/backend/utils/adt/checksumfuncs.c b/src/backend/utils/adt/checksumfuncs.c new file mode 100644 index 0000000000..b53b4c0bbf --- /dev/null +++ b/src/backend/utils/adt/checksumfuncs.c @@ -0,0 +1,96 @@ +/*------------------------------------------------------------------------- + * + * checksumfuncs.c + * Functions for checksums related feature such as online verification + * + * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/utils/adt/checksumfuncs.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/xlog.h" +#include "catalog/pg_authid_d.h" +#include "funcapi.h" +#include "miscadmin.h" +#include "storage/checksum.h" +#include "utils/acl.h" +#include "utils/builtins.h" + +Datum +pg_check_relation(PG_FUNCTION_ARGS) +{ + ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + TupleDesc tupdesc; + Tuplestorestate *tupstore; + MemoryContext per_query_ctx; + MemoryContext oldcontext; + ForkNumber forknum = InvalidForkNumber; + Oid relid = InvalidOid; + const char *forkname; + + if (!DataChecksumsEnabled()) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("data checksums are not enabled in cluster"))); + + if (!is_member_of_role(GetUserId(), DEFAULT_ROLE_READ_SERVER_FILES)) + ereport(ERROR, + (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), + errmsg("only superuser or a member of the pg_read_server_files role may use this function"))); + + if (PG_ARGISNULL(0)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("relation cannot be null"))); + + /* check to see if caller supports us returning a tuplestore */ + if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("set-valued function called in context that cannot accept a set"))); + if (!(rsinfo->allowedModes & SFRM_Materialize)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("materialize mode required, but it is not " \ + "allowed in this context"))); + + /* Switch into long-lived context to construct returned data structures */ + per_query_ctx = rsinfo->econtext->ecxt_per_query_memory; + oldcontext = MemoryContextSwitchTo(per_query_ctx); + + /* Build a tuple descriptor for our result type */ + if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) + elog(ERROR, "return type must be a row type"); + + tupstore = tuplestore_begin_heap(true, false, work_mem); + rsinfo->returnMode = SFRM_Materialize; + rsinfo->setResult = tupstore; + rsinfo->setDesc = tupdesc; + + MemoryContextSwitchTo(oldcontext); + + relid = PG_GETARG_OID(0); + + if (PG_NARGS() == 2 && !PG_ARGISNULL(1)) + { + forkname = TextDatumGetCString(PG_GETARG_TEXT_PP(1)); + forknum = forkname_to_number(forkname); + } + + /* Set cost-based vacuum delay */ + ChecksumCostActive = (ChecksumCostDelay > 0); + ChecksumCostBalance = 0; + + check_one_relation(tupdesc, tupstore, relid, forknum); + + tuplestore_donestoring(tupstore); + + return (Datum) 0; +} + diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c index eb19644419..8683343619 100644 --- a/src/backend/utils/init/globals.c +++ b/src/backend/utils/init/globals.c @@ -134,6 +134,13 @@ int max_worker_processes = 8; int max_parallel_workers = 8; int MaxBackends = 0; +int ChecksumCostPage = 10; /* GUC parameters for checksum check */ +int ChecksumCostLimit = 200; +double ChecksumCostDelay = 0; + +int ChecksumCostBalance = 0; /* working state for checksums check */ +bool ChecksumCostActive = false; + int VacuumCostPageHit = 1; /* GUC parameters for vacuum */ int VacuumCostPageMiss = 10; int VacuumCostPageDirty = 20; diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 79bc7ac8ca..a4e1fb0f77 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -693,6 +693,8 @@ const char *const config_group_names[] = gettext_noop("Resource Usage / Disk"), /* RESOURCES_KERNEL */ gettext_noop("Resource Usage / Kernel Resources"), + /* RESOURCES_CHECKSUM_DELAY */ + gettext_noop("Resource Usage / Cost-Based Checksum Verification Delay"), /* RESOURCES_VACUUM_DELAY */ gettext_noop("Resource Usage / Cost-Based Vacuum Delay"), /* RESOURCES_BGWRITER */ @@ -2396,6 +2398,26 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"checksum_cost_page", PGC_USERSET, RESOURCES_CHECKSUM_DELAY, + gettext_noop("Checksum cost for verifying a page found."), + NULL + }, + &ChecksumCostPage, + 10, 0, 10000, + NULL, NULL, NULL + }, + + { + {"checksum_cost_limit", PGC_USERSET, RESOURCES_CHECKSUM_DELAY, + gettext_noop("Checksum cost amount available before napping."), + NULL + }, + &ChecksumCostLimit, + 200, 1, 10000, + NULL, NULL, NULL + }, + { {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES_VACUUM_DELAY, gettext_noop("Vacuum cost for a page found in the buffer cache."), @@ -3527,6 +3549,17 @@ static struct config_real ConfigureNamesReal[] = check_random_seed, assign_random_seed, show_random_seed }, + { + {"checksum_cost_delay", PGC_USERSET, RESOURCES_CHECKSUM_DELAY, + gettext_noop("Checksum cost delay in milliseconds."), + NULL, + GUC_UNIT_MS + }, + &ChecksumCostDelay, + 0, 0, 100, + NULL, NULL, NULL + }, + { {"vacuum_cost_delay", PGC_USERSET, RESOURCES_VACUUM_DELAY, gettext_noop("Vacuum cost delay in milliseconds."), diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index e9f8ca775d..36120787fd 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -156,6 +156,12 @@ #max_files_per_process = 1000 # min 64 # (change requires restart) +# - Cost-Based Checksum Verification Delay - + +#checksum_cost_delay = 0 # 0-100 milliseconds (0 disables) +#checksum_cost_page = 10 # 0-10000 credits +#checksum_cost_limit = 200 # 1-10000 credits + # - Cost-Based Vacuum Delay - #vacuum_cost_delay = 0 # 0-100 milliseconds (0 disables) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index ac8ad8dbf0..7cd005b891 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -10798,6 +10798,14 @@ proallargtypes => '{oid,text,int8,timestamptz}', proargmodes => '{i,o,o,o}', proargnames => '{tablespace,name,size,modification}', prosrc => 'pg_ls_tmpdir_1arg' }, +{ oid => '9147', descr => 'check data integrity for one or all relations', + proname => 'pg_check_relation', proisstrict => 'f', procost => '10000', + prorows => '20', proretset => 't', proparallel => 'r', + provolatile => 'v', prorettype => 'record', proargtypes => 'regclass text', + proallargtypes => '{regclass,text,oid,int4,int8,int4,int4}', + proargmodes => '{i,i,o,o,o,o,o}', + proargnames => '{relation,fork,relid,forknum,failed_blocknum,expected_checksum,found_checksum}', + prosrc => 'pg_check_relation' }, # hash partitioning constraint function { oid => '5028', descr => 'hash partition CHECK constraint', diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h index 14fa127ab1..8d4605efc8 100644 --- a/src/include/miscadmin.h +++ b/src/include/miscadmin.h @@ -246,6 +246,13 @@ extern PGDLLIMPORT int work_mem; extern PGDLLIMPORT int maintenance_work_mem; extern PGDLLIMPORT int max_parallel_maintenance_workers; +extern int ChecksumCostPage; +extern int ChecksumCostLimit; +extern double ChecksumCostDelay; + +extern int ChecksumCostBalance; +extern bool ChecksumCostActive; + extern int VacuumCostPageHit; extern int VacuumCostPageMiss; extern int VacuumCostPageDirty; diff --git a/src/include/storage/checksum.h b/src/include/storage/checksum.h index 6e77744cbc..29ca52d8c9 100644 --- a/src/include/storage/checksum.h +++ b/src/include/storage/checksum.h @@ -13,8 +13,15 @@ #ifndef CHECKSUM_H #define CHECKSUM_H +#include "postgres.h" + +#include "access/tupdesc.h" +#include "common/relpath.h" #include "storage/block.h" +#include "utils/tuplestore.h" +extern void check_one_relation(TupleDesc tupdesc, Tuplestorestate *tupstore, + Oid relid, ForkNumber single_forknum); /* * Compute the checksum for a Postgres page. The page must be aligned on a * 4-byte boundary. diff --git a/src/include/utils/guc_tables.h b/src/include/utils/guc_tables.h index 454c2df487..84965d3f09 100644 --- a/src/include/utils/guc_tables.h +++ b/src/include/utils/guc_tables.h @@ -62,6 +62,7 @@ enum config_group RESOURCES_MEM, RESOURCES_DISK, RESOURCES_KERNEL, + RESOURCES_CHECKSUM_DELAY, RESOURCES_VACUUM_DELAY, RESOURCES_BGWRITER, RESOURCES_ASYNCHRONOUS, diff --git a/src/test/Makefile b/src/test/Makefile index efb206aa75..832868099f 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 check_relation \ + recovery subscription # 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/check_relation/.gitignore b/src/test/check_relation/.gitignore new file mode 100644 index 0000000000..871e943d50 --- /dev/null +++ b/src/test/check_relation/.gitignore @@ -0,0 +1,2 @@ +# Generated by test suite +/tmp_check/ diff --git a/src/test/check_relation/Makefile b/src/test/check_relation/Makefile new file mode 100644 index 0000000000..792098fa65 --- /dev/null +++ b/src/test/check_relation/Makefile @@ -0,0 +1,23 @@ +#------------------------------------------------------------------------- +# +# Makefile for src/test/check_relation +# +# Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group +# Portions Copyright (c) 1994, Regents of the University of California +# +# src/test/check_relation/Makefile +# +#------------------------------------------------------------------------- + +subdir = src/test/check_relation +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/check_relation/README b/src/test/check_relation/README new file mode 100644 index 0000000000..415c4b21ad --- /dev/null +++ b/src/test/check_relation/README @@ -0,0 +1,23 @@ +src/test/check_relation/README + +Regression tests for online checksums verification +================================================== + +This directory contains a test suite for online checksums verification. + +Running the tests +================= + +NOTE: You must have given the --enable-tap-tests argument to configure. + +Run + make check +or + make installcheck +You can use "make installcheck" if you previously did "make install". +In that case, the code in the installation tree is tested. With +"make check", a temporary installation tree is built from the current +sources and then tested. + +Either way, this test initializes, starts, and stops a test Postgres +cluster. diff --git a/src/test/check_relation/t/01_checksums_check.pl b/src/test/check_relation/t/01_checksums_check.pl new file mode 100644 index 0000000000..af67252ea1 --- /dev/null +++ b/src/test/check_relation/t/01_checksums_check.pl @@ -0,0 +1,276 @@ +use strict; +use warnings; + +use PostgresNode; +use TestLib; +use Test::More tests => 59; + +our $CHECKSUM_UINT16_OFFSET = 4; +our $PD_UPPER_UINT16_OFFSET = 7; +our $BLOCKSIZE; +our $TOTAL_NB_ERR = 0; + +sub get_block +{ + my ($filename, $blkno) = @_; + my $block; + + open(my $infile, '<', $filename) or die; + binmode($infile); + + my $success = read($infile, $block, $BLOCKSIZE, ($blkno * $BLOCKSIZE)); + die($!) if not defined $success; + + close($infile); + + return($block); +} + +sub overwrite_block +{ + my ($filename, $block, $blkno) = @_; + + open(my $outfile, '>', $filename) or die; + binmode ($outfile); + + my $nb = syswrite($outfile, $block, $BLOCKSIZE, ($blkno * $BLOCKSIZE)); + + die($!) if not defined $nb; + die("Write error") if ($nb != $BLOCKSIZE); + + $outfile->flush(); + + close($outfile); +} + +sub get_uint16_from_page +{ + my ($block, $offset) = @_; + + return (unpack("S*", $block))[$offset]; +} + +sub set_uint16_to_page +{ + my ($block, $data, $offset) = @_; + + my $pack = pack("S", $data); + + # vec with 16B or more won't preserve endianness + vec($block, 2*$offset, 8) = (unpack('C*', $pack))[0]; + vec($block, (2*$offset) + 1, 8) = (unpack('C*', $pack))[1]; + + return $block; +} + +sub check_checksums_call +{ + my ($node, $relname) = @_; + + my ($cmdret, $stdout, $stderr) = $node->psql('postgres', "SELECT COUNT(*)" + . " FROM pg_catalog.pg_check_relation('$relname')" + ); + + return ($stderr eq ''); +} + +sub check_checksums_nb_error +{ + my ($node, $nb, $pattern) = @_; + + my ($cmdret, $stdout, $stderr) = $node->psql('postgres', "SELECT COUNT(*)" + . " FROM (SELECT pg_catalog.pg_check_relation(oid)" + . " FROM pg_class WHERE relkind in ('r', 'i', 'm')) AS s" + ); + + is($cmdret, 0, 'Function should run successfully'); + like($stderr, $pattern, 'Error output should match expectations'); + is($stdout, $nb, "Should have $nb error"); + + $TOTAL_NB_ERR += $nb; +} + +sub check_pg_stat_database_nb_error +{ + my ($node) = @_; + + my ($cmdret, $stdout, $stderr) = $node->psql('postgres', "SELECT " + . " sum(checksum_failures)" + . " FROM pg_catalog.pg_stat_database" + ); + + is($cmdret, 0, 'Function should run successfully'); + is($stderr, '', 'Function should run successfully'); + is($stdout, $TOTAL_NB_ERR, "Should have $TOTAL_NB_ERR error"); +} + +sub get_checksums_errors +{ + my ($node, $nb, $pattern) = @_; + + my ($cmdret, $stdout, $stderr) = $node->psql('postgres', "SELECT" + . " relid::regclass::text, forknum, failed_blocknum," + . " expected_checksum, found_checksum" + . " FROM (SELECT (pg_catalog.pg_check_relation(oid)).*" + . " FROM pg_class WHERE relkind in ('r','i', 'm')) AS s" + ); + + is($cmdret, '0', 'Function should run successfully'); + like($stderr, $pattern, 'Error output should match expectations'); + + $TOTAL_NB_ERR += $nb; + + return $stdout; +} + +# This function will perform various test by modifying the specified block at +# the specified uint16 offset, checking that the corruption is correctly +# detected, and finally restore the specified block to its original content. +sub corrupt_and_test_block +{ + my ($node, $filename, $blkno, $offset, $fake_data) = @_; + + check_checksums_nb_error($node, 0, qr/^$/); + +check_pg_stat_database_nb_error($node); + + $node->stop(); + + my $original_block = get_block($filename, 0); + my $original_data = get_uint16_from_page($original_block, $offset); + + isnt($original_data, $fake_data, + "The fake data at offset $offset should be different" + . " from the existing one"); + + my $new_block = set_uint16_to_page($original_block, $fake_data, $offset); + isnt($original_data, get_uint16_from_page($new_block, $offset), + "The fake data at offset $offset should have been changed in memory"); + + overwrite_block($filename, $new_block, 0); + + my $written_data = get_uint16_from_page(get_block($filename, 0), $offset); + isnt($original_data, $written_data, + "The data written at offset $offset should be different" + . " from the original one"); + is(get_uint16_from_page($new_block, $offset), $written_data, + "The data written at offset $offset should be the same" + . " as the one in memory"); + is($written_data, $fake_data, + "The data written at offset $offset should be the one" + . " we wanted to write"); + + $node->start(); + + check_checksums_nb_error($node, 1, qr/invalid page in block $blkno/); + + my $expected_checksum; + my $found_checksum = get_uint16_from_page($new_block, + $CHECKSUM_UINT16_OFFSET); + if ($offset == $PD_UPPER_UINT16_OFFSET) + { + # A checksum can't be computed if it's detected as PageIsNew(), so the + # function returns NULL for the computed checksum + $expected_checksum = ''; + } + else + { + $expected_checksum = get_uint16_from_page($original_block, + $CHECKSUM_UINT16_OFFSET); + } + + my $det = get_checksums_errors($node, 1, qr/invalid page in block $blkno/); + is($det, "t1|0|0|$expected_checksum|$found_checksum", + "The checksums error for modification at offset $offset" + . " should be detected"); + + $node->stop(); + + $new_block = set_uint16_to_page($original_block, $original_data, $offset); + is($original_data, get_uint16_from_page($new_block, $offset), + "The data at offset $offset should have been restored in memory"); + + overwrite_block($filename, $new_block, 0); + is($original_data, get_uint16_from_page(get_block($filename, $blkno), + $offset), + "The data at offset $offset should have been restored on disk"); + + $node->start(); + + check_checksums_nb_error($node, 0, qr/^$/); +} + +if (exists $ENV{MY_PG_REGRESS}) +{ + $ENV{PG_REGRESS} = $ENV{MY_PG_REGRESS}; +} + +my $node = get_new_node('main'); + +my %params; +$params{'extra'} = ['--data-checksums']; +$node->init(%params); + +$node->start(); + +$ENV{PGOPTIONS} = '--client-min-messages=WARNING'; + +my ($cmdret, $stdout, $stderr) = $node->psql('postgres', "SELECT" + . " current_setting('data_checksums')"); + +is($stdout, 'on', 'Data checksums shoud be enabled'); + +($cmdret, $stdout, $stderr) = $node->psql('postgres', "SELECT" + . " current_setting('block_size')"); + +$BLOCKSIZE = $stdout; + +$node->safe_psql( + 'postgres', q| + CREATE TABLE public.t1(id integer); + CREATE INDEX t1_id_idx ON public.t1 (id); + INSERT INTO public.t1 SELECT generate_series(1, 100); + CREATE VIEW public.v1 AS SELECT * FROM t1; + CREATE MATERIALIZED VIEW public.mv1 AS SELECT * FROM t1; + CREATE SEQUENCE public.s1; + CREATE UNLOGGED TABLE public.u_t1(id integer); + CREATE INDEX u_t1_id_idx ON public.u_t1 (id); + INSERT INTO public.u_t1 SELECT generate_series(1, 100); + CHECKPOINT; +|); + +# Check sane behavior on various objects type, including those that don't have +# a storage. +is(check_checksums_call($node, 't1'), '1', 'Can check a table'); +is(check_checksums_call($node, 't1_id_idx'), '1', 'Can check an index'); +is(check_checksums_call($node, 'v1'), '', 'Cannot check a view'); +is(check_checksums_call($node, 'mv1'), '1', 'Can check a materialized view'); +is(check_checksums_call($node, 's1'), '1', 'Can check a sequence'); +is(check_checksums_call($node, 'u_t1'), '1', 'Can check an unlogged table'); +is(check_checksums_call($node, 'u_t1_id_idx'), '1', 'Can check an unlogged index'); + +# get the underlying heap absolute path +($cmdret, $stdout, $stderr) = $node->psql('postgres', "SELECT" + . " current_setting('data_directory') || '/' || pg_relation_filepath('t1')" +); + +isnt($stdout, '', 'A relfinode should be returned'); + +my $filename = $stdout; + +check_checksums_nb_error($node, 0, qr/^$/); + +check_pg_stat_database_nb_error($node); + +my $fake_uint16 = hex '0x0000'; + +# Test with a modified checksum. We use a zero checksum here as it's the only +# one that cannot exist on a checksummed page. We also don't have an easy way +# to compute what the checksum would be after a modification in a random place +# in the block. +corrupt_and_test_block($node, $filename, 0, $CHECKSUM_UINT16_OFFSET, + $fake_uint16); + +# Test corruption making the block looks like it's PageIsNew(). +corrupt_and_test_block($node, $filename, 0, $PD_UPPER_UINT16_OFFSET, + $fake_uint16); -- 2.20.1