From 670fe40df53b44056845045b757d0d04f2fe28de Mon Sep 17 00:00:00 2001 From: Kyotaro Horiguchi Date: Tue, 12 Apr 2022 18:00:07 +0900 Subject: [PATCH v2] Fix ABI/API break Commit 1ce14b6b2f caused ABI break by changing the type and width of PGPROC.delayChkpt and API break by changing the signature of some public functions. Restore the member and function signature to previous state and add delayChkptEnd to an existing gap in PGPROC struct. Backpatch to 10, all supported branches. --- src/backend/access/transam/multixact.c | 6 +-- src/backend/access/transam/twophase.c | 13 +++--- src/backend/access/transam/xact.c | 5 +-- src/backend/access/transam/xlog.c | 10 ++--- src/backend/access/transam/xloginsert.c | 2 +- src/backend/catalog/storage.c | 6 +-- src/backend/storage/buffer/bufmgr.c | 6 +-- src/backend/storage/ipc/procarray.c | 59 +++++++++++++++++++------ src/backend/storage/lmgr/proc.c | 6 ++- src/include/storage/proc.h | 43 +++--------------- src/include/storage/procarray.h | 9 ++-- 11 files changed, 82 insertions(+), 83 deletions(-) diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c index 3e6443fd41..7990b5e5dd 100644 --- a/src/backend/access/transam/multixact.c +++ b/src/backend/access/transam/multixact.c @@ -3071,8 +3071,8 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB) * crash/basebackup, even though the state of the data directory would * require it. */ - Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0); - MyProc->delayChkpt |= DELAY_CHKPT_START; + Assert(!MyProc->delayChkpt); + MyProc->delayChkpt = true; /* WAL log truncation */ WriteMTruncateXlogRec(newOldestMultiDB, @@ -3098,7 +3098,7 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB) /* Then offsets */ PerformOffsetsTruncation(oldestMulti, newOldestMulti); - MyProc->delayChkpt &= ~DELAY_CHKPT_START; + MyProc->delayChkpt = false; END_CRIT_SECTION(); LWLockRelease(MultiXactTruncationLock); diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c index 716c17c98f..4c58c7579a 100644 --- a/src/backend/access/transam/twophase.c +++ b/src/backend/access/transam/twophase.c @@ -476,7 +476,8 @@ MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid, } pgxact->xid = xid; pgxact->xmin = InvalidTransactionId; - proc->delayChkpt = 0; + proc->delayChkpt = false; + proc->delayChkptEnd = false; pgxact->vacuumFlags = 0; proc->pid = 0; proc->databaseId = databaseid; @@ -1170,8 +1171,7 @@ EndPrepare(GlobalTransaction gxact) START_CRIT_SECTION(); - Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0); - MyProc->delayChkpt |= DELAY_CHKPT_START; + MyProc->delayChkpt = true; XLogBeginInsert(); for (record = records.head; record != NULL; record = record->next) @@ -1214,7 +1214,7 @@ EndPrepare(GlobalTransaction gxact) * checkpoint starting after this will certainly see the gxact as a * candidate for fsyncing. */ - MyProc->delayChkpt &= ~DELAY_CHKPT_START; + MyProc->delayChkpt = false; /* * Remember that we have this GlobalTransaction entry locked for us. If @@ -2287,8 +2287,7 @@ RecordTransactionCommitPrepared(TransactionId xid, START_CRIT_SECTION(); /* See notes in RecordTransactionCommit */ - Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0); - MyProc->delayChkpt |= DELAY_CHKPT_START; + MyProc->delayChkpt = true; /* * Emit the XLOG commit record. Note that we mark 2PC commits as @@ -2336,7 +2335,7 @@ RecordTransactionCommitPrepared(TransactionId xid, TransactionIdCommitTree(xid, nchildren, children); /* Checkpoint can proceed now */ - MyProc->delayChkpt &= ~DELAY_CHKPT_START; + MyProc->delayChkpt = false; END_CRIT_SECTION(); diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index da6ce5a09e..fb6220e491 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1308,9 +1308,8 @@ RecordTransactionCommit(void) * This makes checkpoint's determination of which xacts are delayChkpt * a bit fuzzy, but it doesn't matter. */ - Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0); START_CRIT_SECTION(); - MyProc->delayChkpt |= DELAY_CHKPT_START; + MyProc->delayChkpt = true; SetCurrentTransactionStopTimestamp(); @@ -1411,7 +1410,7 @@ RecordTransactionCommit(void) */ if (markXidCommitted) { - MyProc->delayChkpt &= ~DELAY_CHKPT_START; + MyProc->delayChkpt = false; END_CRIT_SECTION(); } diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 5ac45e612e..ffc1b8e995 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -9028,27 +9028,25 @@ CreateCheckPoint(int flags) * and we will correctly flush the update below. So we cannot miss any * xacts we need to wait for. */ - vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_START); + vxids = GetVirtualXIDsDelayingChkpt(&nvxids); if (nvxids > 0) { do { pg_usleep(10000L); /* wait for 10 msec */ - } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids, - DELAY_CHKPT_START)); + } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids)); } pfree(vxids); CheckPointGuts(checkPoint.redo, flags); - vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_COMPLETE); + vxids = GetVirtualXIDsDelayingChkptEnd(&nvxids); if (nvxids > 0) { do { pg_usleep(10000L); /* wait for 10 msec */ - } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids, - DELAY_CHKPT_COMPLETE)); + } while (HaveVirtualXIDsDelayingChkptEnd(vxids, nvxids)); } pfree(vxids); diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c index 5cff486d9e..b21679f09e 100644 --- a/src/backend/access/transam/xloginsert.c +++ b/src/backend/access/transam/xloginsert.c @@ -904,7 +904,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std) /* * Ensure no checkpoint can change our view of RedoRecPtr. */ - Assert((MyProc->delayChkpt & DELAY_CHKPT_START) != 0); + Assert(MyProc->delayChkpt); /* * Update RedoRecPtr so that we can make the right decision diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c index 0eb14cc885..d7c74105a4 100644 --- a/src/backend/catalog/storage.c +++ b/src/backend/catalog/storage.c @@ -338,8 +338,8 @@ RelationTruncate(Relation rel, BlockNumber nblocks) * the blocks to not exist on disk at all, but not for them to have the * wrong contents. */ - Assert((MyProc->delayChkpt & DELAY_CHKPT_COMPLETE) == 0); - MyProc->delayChkpt |= DELAY_CHKPT_COMPLETE; + Assert(!MyProc->delayChkptEnd); + MyProc->delayChkptEnd = true; /* * We WAL-log the truncation before actually truncating, which means @@ -387,7 +387,7 @@ RelationTruncate(Relation rel, BlockNumber nblocks) smgrtruncate(rel->rd_smgr, forks, nforks, blocks); /* We've done all the critical work, so checkpoints are OK now. */ - MyProc->delayChkpt &= ~DELAY_CHKPT_COMPLETE; + MyProc->delayChkptEnd = false; /* * Update upper-level FSM pages to account for the truncation. This is diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index 033ef46811..597afedef7 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -3647,9 +3647,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std) * essential that CreateCheckpoint waits for virtual transactions * rather than full transactionids. */ - Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0); - MyProc->delayChkpt |= DELAY_CHKPT_START; - delayChkpt = true; + MyProc->delayChkpt = delayChkpt = true; lsn = XLogSaveBufferForHint(buffer, buffer_std); } @@ -3682,7 +3680,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std) UnlockBufHdr(bufHdr, buf_state); if (delayChkpt) - MyProc->delayChkpt &= ~DELAY_CHKPT_START; + MyProc->delayChkpt = false; if (dirtied) { diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 725680f34f..88853d25c6 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -175,6 +175,10 @@ static void KnownAssignedXidsReset(void); static inline void ProcArrayEndTransactionInternal(PGPROC *proc, PGXACT *pgxact, TransactionId latestXid); static void ProcArrayGroupClearXid(PGPROC *proc, TransactionId latestXid); +static VirtualTransactionId *GetVirtualXIDsDelayingChkptGuts(int *nvxids, + bool start); +static bool HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids, + int nvxids, bool start); /* * Report shared-memory space needed by CreateSharedProcArray. @@ -435,8 +439,9 @@ ProcArrayEndTransaction(PGPROC *proc, TransactionId latestXid) /* must be cleared with xid/xmin: */ pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK; - /* be sure this is cleared in abort */ - proc->delayChkpt = 0; + /* be sure these are cleared in abort */ + proc->delayChkpt = false; + proc->delayChkptEnd = false; proc->recoveryConflictPending = false; @@ -460,8 +465,9 @@ ProcArrayEndTransactionInternal(PGPROC *proc, PGXACT *pgxact, /* must be cleared with xid/xmin: */ pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK; - /* be sure this is cleared in abort */ - proc->delayChkpt = 0; + /* be sure these are cleared in abort */ + proc->delayChkpt = false; + proc->delayChkptEnd = false; proc->recoveryConflictPending = false; @@ -2278,8 +2284,9 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly) * delaying checkpoint because they have critical actions in progress. * * Constructs an array of VXIDs of transactions that are currently in commit - * critical sections, as shown by having specified delayChkpt bits set in their - * PGPROC. + * critical sections, as shown by having the corresponding flag set in + * their PGPROC. GetVirtualXIDsDelayingChkpt checks delayChkpt, and + * GetVirtualXIDsDelayingChkptEnd checks delayChkptEnd. * * Returns a palloc'd array that should be freed by the caller. * *nvxids is the number of valid entries. @@ -2293,15 +2300,25 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly) * for clearing of delayChkpt to propagate is unimportant for correctness. */ VirtualTransactionId * -GetVirtualXIDsDelayingChkpt(int *nvxids, int type) +GetVirtualXIDsDelayingChkpt(int *nvxids) +{ + return GetVirtualXIDsDelayingChkptGuts(nvxids, true); +} + +VirtualTransactionId * +GetVirtualXIDsDelayingChkptEnd(int *nvxids) +{ + return GetVirtualXIDsDelayingChkptGuts(nvxids, false); +} + +static VirtualTransactionId * +GetVirtualXIDsDelayingChkptGuts(int *nvxids, bool start) { VirtualTransactionId *vxids; ProcArrayStruct *arrayP = procArray; int count = 0; int index; - Assert(type != 0); - /* allocate what's certainly enough result space */ vxids = (VirtualTransactionId *) palloc(sizeof(VirtualTransactionId) * arrayP->maxProcs); @@ -2313,7 +2330,7 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type) int pgprocno = arrayP->pgprocnos[index]; PGPROC *proc = &allProcs[pgprocno]; - if ((proc->delayChkpt & type) != 0) + if (start ? proc->delayChkpt : proc->delayChkptEnd) { VirtualTransactionId vxid; @@ -2335,18 +2352,32 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type) * This is used with the results of GetVirtualXIDsDelayingChkpt to see if any * of the specified VXIDs are still in critical sections of code. * + * HaveVirtualXIDsDelayingChkptEnd corresponds to + * GetVirtualXIDsDelayingChkptEnd above. + * * Note: this is O(N^2) in the number of vxacts that are/were delaying, but * those numbers should be small enough for it not to be a problem. */ bool -HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type) +HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids) +{ + return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, true); +} + +bool +HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids, int nvxids) +{ + return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, false); +} + +static bool +HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids, int nvxids, + bool start) { bool result = false; ProcArrayStruct *arrayP = procArray; int index; - Assert(type != 0); - LWLockAcquire(ProcArrayLock, LW_SHARED); for (index = 0; index < arrayP->numProcs; index++) @@ -2357,7 +2388,7 @@ HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type) GET_VXID_FROM_PGPROC(vxid, *proc); - if ((proc->delayChkpt & type) != 0 && + if ((start ? proc->delayChkpt : proc->delayChkptEnd) && VirtualTransactionIdIsValid(vxid)) { int i; diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index f3a6c598bf..3d8b0c7098 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -396,7 +396,8 @@ InitProcess(void) MyProc->roleId = InvalidOid; MyProc->tempNamespaceId = InvalidOid; MyProc->isBackgroundWorker = IsBackgroundWorker; - MyProc->delayChkpt = 0; + MyProc->delayChkpt = false; + MyProc->delayChkptEnd = false; MyPgXact->vacuumFlags = 0; /* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */ if (IsAutoVacuumWorkerProcess()) @@ -578,7 +579,8 @@ InitAuxiliaryProcess(void) MyProc->roleId = InvalidOid; MyProc->tempNamespaceId = InvalidOid; MyProc->isBackgroundWorker = IsBackgroundWorker; - MyProc->delayChkpt = 0; + MyProc->delayChkpt = false; + MyProc->delayChkptEnd = false; MyPgXact->vacuumFlags = 0; MyProc->lwWaiting = false; MyProc->lwWaitMode = 0; diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index 5798b91186..878a6b12e8 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -83,41 +83,6 @@ struct XidCache */ #define INVALID_PGPROCNO PG_INT32_MAX -/* - * Flags for PGPROC.delayChkpt - * - * These flags can be used to delay the start or completion of a checkpoint - * for short periods. A flag is in effect if the corresponding bit is set in - * the PGPROC of any backend. - * - * For our purposes here, a checkpoint has three phases: (1) determine the - * location to which the redo pointer will be moved, (2) write all the - * data durably to disk, and (3) WAL-log the checkpoint. - * - * Setting DELAY_CHKPT_START prevents the system from moving from phase 1 - * to phase 2. This is useful when we are performing a WAL-logged modification - * of data that will be flushed to disk in phase 2. By setting this flag - * before writing WAL and clearing it after we've both written WAL and - * performed the corresponding modification, we ensure that if the WAL record - * is inserted prior to the new redo point, the corresponding data changes will - * also be flushed to disk before the checkpoint can complete. (In the - * extremely common case where the data being modified is in shared buffers - * and we acquire an exclusive content lock on the relevant buffers before - * writing WAL, this mechanism is not needed, because phase 2 will block - * until we release the content lock and then flush the modified data to - * disk.) - * - * Setting DELAY_CHKPT_COMPLETE prevents the system from moving from phase 2 - * to phase 3. This is useful if we are performing a WAL-logged operation that - * might invalidate buffers, such as relation truncation. In this case, we need - * to ensure that any buffers which were invalidated and thus not flushed by - * the checkpoint are actaully destroyed on disk. Replay can cope with a file - * or block that doesn't exist, but not with a block that has the wrong - * contents. - */ -#define DELAY_CHKPT_START (1<<0) -#define DELAY_CHKPT_COMPLETE (1<<1) - /* * Each backend has a PGPROC struct in shared memory. There is also a list of * currently-unused PGPROC structs that will be reallocated to new backends. @@ -184,7 +149,13 @@ struct PGPROC LOCKMASK heldLocks; /* bitmask for lock types already held on this * lock object by this backend */ - int delayChkpt; /* for DELAY_CHKPT_* flags */ + bool delayChkpt; /* true if this proc delays checkpoint start */ + + /* + * delayChkptEnd is placed here to prevent ABI breakage by moving other + * struct members around. + */ + bool delayChkptEnd; /* true if this proc delays checkpoint end */ /* * Info to allow us to wait for synchronous replication, if needed. diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h index 4dee2dab10..e6b5fe6153 100644 --- a/src/include/storage/procarray.h +++ b/src/include/storage/procarray.h @@ -91,10 +91,11 @@ extern bool TransactionIdIsActive(TransactionId xid); extern TransactionId GetOldestXmin(Relation rel, int flags); extern TransactionId GetOldestActiveTransactionId(void); extern TransactionId GetOldestSafeDecodingTransactionId(bool catalogOnly); - -extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids, int type); -extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, - int nvxids, int type); +extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids); +extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids); +extern VirtualTransactionId *GetVirtualXIDsDelayingChkptEnd(int *nvxids); +extern bool HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids, + int nvxids); extern PGPROC *BackendPidGetProc(int pid); extern PGPROC *BackendPidGetProcWithLock(int pid); -- 2.27.0