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to write out data that we are about to tell the filesystem to drop. smgr_internal_unlink already had a DropRelFileNodeBuffers call to get rid of dead buffers without a write after it's no longer possible to roll back the deleting transaction. Adding a similar call in smgrtruncate simplifies callers and makes the overall division of labor clearer. This patch removes the former behavior that VACUUM would write all dirty buffers of a relation unconditionally.
946 lines
26 KiB
C
946 lines
26 KiB
C
/*-------------------------------------------------------------------------
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*
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* smgr.c
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* public interface routines to storage manager switch.
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*
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* All file system operations in POSTGRES dispatch through these
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* routines.
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*
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* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.86 2005/03/20 22:00:53 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/xact.h"
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#include "commands/tablespace.h"
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#include "storage/bufmgr.h"
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#include "storage/freespace.h"
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#include "storage/ipc.h"
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#include "storage/smgr.h"
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#include "utils/hsearch.h"
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#include "utils/memutils.h"
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/*
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* This struct of function pointers defines the API between smgr.c and
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* any individual storage manager module. Note that smgr subfunctions are
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* generally expected to return TRUE on success, FALSE on error. (For
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* nblocks and truncate we instead say that returning InvalidBlockNumber
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* indicates an error.)
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*/
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typedef struct f_smgr
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{
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bool (*smgr_init) (void); /* may be NULL */
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bool (*smgr_shutdown) (void); /* may be NULL */
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bool (*smgr_close) (SMgrRelation reln);
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bool (*smgr_create) (SMgrRelation reln, bool isRedo);
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bool (*smgr_unlink) (RelFileNode rnode, bool isRedo);
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bool (*smgr_extend) (SMgrRelation reln, BlockNumber blocknum,
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char *buffer, bool isTemp);
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bool (*smgr_read) (SMgrRelation reln, BlockNumber blocknum,
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char *buffer);
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bool (*smgr_write) (SMgrRelation reln, BlockNumber blocknum,
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char *buffer, bool isTemp);
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BlockNumber (*smgr_nblocks) (SMgrRelation reln);
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BlockNumber (*smgr_truncate) (SMgrRelation reln, BlockNumber nblocks,
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bool isTemp);
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bool (*smgr_immedsync) (SMgrRelation reln);
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bool (*smgr_commit) (void); /* may be NULL */
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bool (*smgr_abort) (void); /* may be NULL */
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bool (*smgr_sync) (void); /* may be NULL */
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} f_smgr;
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static const f_smgr smgrsw[] = {
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/* magnetic disk */
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{mdinit, NULL, mdclose, mdcreate, mdunlink, mdextend,
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mdread, mdwrite, mdnblocks, mdtruncate, mdimmedsync,
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NULL, NULL, mdsync
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}
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};
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static const int NSmgr = lengthof(smgrsw);
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/*
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* Each backend has a hashtable that stores all extant SMgrRelation objects.
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*/
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static HTAB *SMgrRelationHash = NULL;
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/*
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* We keep a list of all relations (represented as RelFileNode values)
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* that have been created or deleted in the current transaction. When
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* a relation is created, we create the physical file immediately, but
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* remember it so that we can delete the file again if the current
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* transaction is aborted. Conversely, a deletion request is NOT
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* executed immediately, but is just entered in the list. When and if
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* the transaction commits, we can delete the physical file.
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*
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* To handle subtransactions, every entry is marked with its transaction
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* nesting level. At subtransaction commit, we reassign the subtransaction's
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* entries to the parent nesting level. At subtransaction abort, we can
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* immediately execute the abort-time actions for all entries of the current
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* nesting level.
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*
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* NOTE: the list is kept in TopMemoryContext to be sure it won't disappear
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* unbetimes. It'd probably be OK to keep it in TopTransactionContext,
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* but I'm being paranoid.
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*/
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typedef struct PendingRelDelete
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{
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RelFileNode relnode; /* relation that may need to be deleted */
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int which; /* which storage manager? */
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bool isTemp; /* is it a temporary relation? */
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bool atCommit; /* T=delete at commit; F=delete at abort */
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int nestLevel; /* xact nesting level of request */
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struct PendingRelDelete *next; /* linked-list link */
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} PendingRelDelete;
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static PendingRelDelete *pendingDeletes = NULL; /* head of linked list */
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/*
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* Declarations for smgr-related XLOG records
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*
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* Note: we log file creation and truncation here, but logging of deletion
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* actions is handled by xact.c, because it is part of transaction commit.
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*/
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/* XLOG gives us high 4 bits */
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#define XLOG_SMGR_CREATE 0x10
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#define XLOG_SMGR_TRUNCATE 0x20
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typedef struct xl_smgr_create
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{
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RelFileNode rnode;
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} xl_smgr_create;
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typedef struct xl_smgr_truncate
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{
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BlockNumber blkno;
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RelFileNode rnode;
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} xl_smgr_truncate;
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/* local function prototypes */
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static void smgrshutdown(int code, Datum arg);
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static void smgr_internal_unlink(RelFileNode rnode, int which,
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bool isTemp, bool isRedo);
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/*
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* smgrinit(), smgrshutdown() -- Initialize or shut down all storage
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* managers.
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*
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* Note: in the normal multiprocess scenario with a postmaster, these are
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* called at postmaster start and stop, not per-backend.
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*/
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void
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smgrinit(void)
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{
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int i;
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for (i = 0; i < NSmgr; i++)
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{
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if (smgrsw[i].smgr_init)
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{
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if (!(*(smgrsw[i].smgr_init)) ())
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elog(FATAL, "smgr initialization failed on %s: %m",
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DatumGetCString(DirectFunctionCall1(smgrout,
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Int16GetDatum(i))));
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}
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}
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/* register the shutdown proc */
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on_proc_exit(smgrshutdown, 0);
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}
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static void
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smgrshutdown(int code, Datum arg)
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{
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int i;
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for (i = 0; i < NSmgr; i++)
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{
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if (smgrsw[i].smgr_shutdown)
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{
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if (!(*(smgrsw[i].smgr_shutdown)) ())
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elog(FATAL, "smgr shutdown failed on %s: %m",
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DatumGetCString(DirectFunctionCall1(smgrout,
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Int16GetDatum(i))));
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}
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}
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}
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/*
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* smgropen() -- Return an SMgrRelation object, creating it if need be.
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*
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* This does not attempt to actually open the object.
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*/
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SMgrRelation
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smgropen(RelFileNode rnode)
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{
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SMgrRelation reln;
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bool found;
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if (SMgrRelationHash == NULL)
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{
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/* First time through: initialize the hash table */
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HASHCTL ctl;
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MemSet(&ctl, 0, sizeof(ctl));
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ctl.keysize = sizeof(RelFileNode);
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ctl.entrysize = sizeof(SMgrRelationData);
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ctl.hash = tag_hash;
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SMgrRelationHash = hash_create("smgr relation table", 400,
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&ctl, HASH_ELEM | HASH_FUNCTION);
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}
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/* Look up or create an entry */
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reln = (SMgrRelation) hash_search(SMgrRelationHash,
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(void *) &rnode,
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HASH_ENTER, &found);
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if (reln == NULL)
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ereport(ERROR,
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(errcode(ERRCODE_OUT_OF_MEMORY),
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errmsg("out of memory")));
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/* Initialize it if not present before */
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if (!found)
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{
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/* hash_search already filled in the lookup key */
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reln->smgr_owner = NULL;
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reln->smgr_which = 0; /* we only have md.c at present */
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reln->md_fd = NULL; /* mark it not open */
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}
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return reln;
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}
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/*
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* smgrsetowner() -- Establish a long-lived reference to an SMgrRelation object
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*
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* There can be only one owner at a time; this is sufficient since currently
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* the only such owners exist in the relcache.
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*/
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void
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smgrsetowner(SMgrRelation *owner, SMgrRelation reln)
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{
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/*
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* First, unhook any old owner. (Normally there shouldn't be any, but
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* it seems possible that this can happen during swap_relation_files()
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* depending on the order of processing. It's ok to close the old
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* relcache entry early in that case.)
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*/
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if (reln->smgr_owner)
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*(reln->smgr_owner) = NULL;
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/* Now establish the ownership relationship. */
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reln->smgr_owner = owner;
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*owner = reln;
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}
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/*
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* smgrclose() -- Close and delete an SMgrRelation object.
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*/
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void
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smgrclose(SMgrRelation reln)
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{
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SMgrRelation *owner;
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if (!(*(smgrsw[reln->smgr_which].smgr_close)) (reln))
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ereport(ERROR,
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(errcode_for_file_access(),
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errmsg("could not close relation %u/%u/%u: %m",
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reln->smgr_rnode.spcNode,
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reln->smgr_rnode.dbNode,
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reln->smgr_rnode.relNode)));
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owner = reln->smgr_owner;
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if (hash_search(SMgrRelationHash,
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(void *) &(reln->smgr_rnode),
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HASH_REMOVE, NULL) == NULL)
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elog(ERROR, "SMgrRelation hashtable corrupted");
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/*
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* Unhook the owner pointer, if any. We do this last since in the
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* remote possibility of failure above, the SMgrRelation object will still
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* exist.
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*/
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if (owner)
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*owner = NULL;
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}
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/*
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* smgrcloseall() -- Close all existing SMgrRelation objects.
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*/
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void
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smgrcloseall(void)
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{
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HASH_SEQ_STATUS status;
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SMgrRelation reln;
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/* Nothing to do if hashtable not set up */
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if (SMgrRelationHash == NULL)
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return;
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hash_seq_init(&status, SMgrRelationHash);
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while ((reln = (SMgrRelation) hash_seq_search(&status)) != NULL)
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smgrclose(reln);
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}
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/*
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* smgrclosenode() -- Close SMgrRelation object for given RelFileNode,
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* if one exists.
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*
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* This has the same effects as smgrclose(smgropen(rnode)), but it avoids
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* uselessly creating a hashtable entry only to drop it again when no
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* such entry exists already.
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*/
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void
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smgrclosenode(RelFileNode rnode)
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{
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SMgrRelation reln;
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/* Nothing to do if hashtable not set up */
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if (SMgrRelationHash == NULL)
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return;
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reln = (SMgrRelation) hash_search(SMgrRelationHash,
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(void *) &rnode,
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HASH_FIND, NULL);
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if (reln != NULL)
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smgrclose(reln);
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}
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/*
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* smgrcreate() -- Create a new relation.
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*
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* Given an already-created (but presumably unused) SMgrRelation,
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* cause the underlying disk file or other storage to be created.
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*
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* If isRedo is true, it is okay for the underlying file to exist
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* already because we are in a WAL replay sequence. In this case
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* we should make no PendingRelDelete entry; the WAL sequence will
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* tell whether to drop the file.
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*/
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void
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smgrcreate(SMgrRelation reln, bool isTemp, bool isRedo)
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{
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XLogRecPtr lsn;
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XLogRecData rdata;
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xl_smgr_create xlrec;
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PendingRelDelete *pending;
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/*
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* We may be using the target table space for the first time in this
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* database, so create a per-database subdirectory if needed.
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*
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* XXX this is a fairly ugly violation of module layering, but this seems
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* to be the best place to put the check. Maybe
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* TablespaceCreateDbspace should be here and not in
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* commands/tablespace.c? But that would imply importing a lot of
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* stuff that smgr.c oughtn't know, either.
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*/
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TablespaceCreateDbspace(reln->smgr_rnode.spcNode,
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reln->smgr_rnode.dbNode,
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isRedo);
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if (!(*(smgrsw[reln->smgr_which].smgr_create)) (reln, isRedo))
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ereport(ERROR,
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(errcode_for_file_access(),
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errmsg("could not create relation %u/%u/%u: %m",
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reln->smgr_rnode.spcNode,
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reln->smgr_rnode.dbNode,
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reln->smgr_rnode.relNode)));
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if (isRedo)
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return;
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/*
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* Make a non-transactional XLOG entry showing the file creation. It's
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* non-transactional because we should replay it whether the
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* transaction commits or not; if not, the file will be dropped at
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* abort time.
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*/
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xlrec.rnode = reln->smgr_rnode;
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rdata.buffer = InvalidBuffer;
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rdata.data = (char *) &xlrec;
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rdata.len = sizeof(xlrec);
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rdata.next = NULL;
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lsn = XLogInsert(RM_SMGR_ID, XLOG_SMGR_CREATE | XLOG_NO_TRAN, &rdata);
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/* Add the relation to the list of stuff to delete at abort */
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pending = (PendingRelDelete *)
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MemoryContextAlloc(TopMemoryContext, sizeof(PendingRelDelete));
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pending->relnode = reln->smgr_rnode;
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pending->which = reln->smgr_which;
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pending->isTemp = isTemp;
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pending->atCommit = false; /* delete if abort */
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pending->nestLevel = GetCurrentTransactionNestLevel();
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pending->next = pendingDeletes;
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pendingDeletes = pending;
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}
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/*
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* smgrscheduleunlink() -- Schedule unlinking a relation at xact commit.
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*
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* The relation is marked to be removed from the store if we
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* successfully commit the current transaction.
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*
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* This also implies smgrclose() on the SMgrRelation object.
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*/
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void
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smgrscheduleunlink(SMgrRelation reln, bool isTemp)
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{
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PendingRelDelete *pending;
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/* Add the relation to the list of stuff to delete at commit */
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pending = (PendingRelDelete *)
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MemoryContextAlloc(TopMemoryContext, sizeof(PendingRelDelete));
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pending->relnode = reln->smgr_rnode;
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pending->which = reln->smgr_which;
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pending->isTemp = isTemp;
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pending->atCommit = true; /* delete if commit */
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pending->nestLevel = GetCurrentTransactionNestLevel();
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pending->next = pendingDeletes;
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pendingDeletes = pending;
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/*
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* NOTE: if the relation was created in this transaction, it will now
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* be present in the pending-delete list twice, once with atCommit
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* true and once with atCommit false. Hence, it will be physically
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* deleted at end of xact in either case (and the other entry will be
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* ignored by smgrDoPendingDeletes, so no error will occur). We could
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* instead remove the existing list entry and delete the physical file
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* immediately, but for now I'll keep the logic simple.
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*/
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/* Now close the file and throw away the hashtable entry */
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smgrclose(reln);
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}
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|
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/*
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* smgrdounlink() -- Immediately unlink a relation.
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*
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* The relation is removed from the store. This should not be used
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* during transactional operations, since it can't be undone.
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*
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* If isRedo is true, it is okay for the underlying file to be gone
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* already. (In practice isRedo will always be true.)
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*
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* This also implies smgrclose() on the SMgrRelation object.
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*/
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void
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smgrdounlink(SMgrRelation reln, bool isTemp, bool isRedo)
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{
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RelFileNode rnode = reln->smgr_rnode;
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int which = reln->smgr_which;
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/* Close the file and throw away the hashtable entry */
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smgrclose(reln);
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smgr_internal_unlink(rnode, which, isTemp, isRedo);
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}
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|
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/*
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* Shared subroutine that actually does the unlink ...
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*/
|
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static void
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smgr_internal_unlink(RelFileNode rnode, int which, bool isTemp, bool isRedo)
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{
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/*
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* Get rid of any remaining buffers for the relation. bufmgr will just
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* drop them without bothering to write the contents.
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*/
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DropRelFileNodeBuffers(rnode, isTemp, 0);
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|
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/*
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* Tell the free space map to forget this relation. It won't be
|
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* accessed any more anyway, but we may as well recycle the map space
|
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* quickly.
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*/
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|
FreeSpaceMapForgetRel(&rnode);
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|
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/*
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|
* And delete the physical files.
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*
|
|
* Note: we treat deletion failure as a WARNING, not an error, because
|
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* we've already decided to commit or abort the current xact.
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*/
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if (!(*(smgrsw[which].smgr_unlink)) (rnode, isRedo))
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ereport(WARNING,
|
|
(errcode_for_file_access(),
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errmsg("could not remove relation %u/%u/%u: %m",
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rnode.spcNode,
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rnode.dbNode,
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rnode.relNode)));
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}
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|
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/*
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* smgrextend() -- Add a new block to a file.
|
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*
|
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* The semantics are basically the same as smgrwrite(): write at the
|
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* specified position. However, we are expecting to extend the
|
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* relation (ie, blocknum is the current EOF), and so in case of
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* failure we clean up by truncating.
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*/
|
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void
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smgrextend(SMgrRelation reln, BlockNumber blocknum, char *buffer, bool isTemp)
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|
{
|
|
if (!(*(smgrsw[reln->smgr_which].smgr_extend)) (reln, blocknum, buffer,
|
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isTemp))
|
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ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not extend relation %u/%u/%u: %m",
|
|
reln->smgr_rnode.spcNode,
|
|
reln->smgr_rnode.dbNode,
|
|
reln->smgr_rnode.relNode),
|
|
errhint("Check free disk space.")));
|
|
}
|
|
|
|
/*
|
|
* smgrread() -- read a particular block from a relation into the supplied
|
|
* buffer.
|
|
*
|
|
* This routine is called from the buffer manager in order to
|
|
* instantiate pages in the shared buffer cache. All storage managers
|
|
* return pages in the format that POSTGRES expects.
|
|
*/
|
|
void
|
|
smgrread(SMgrRelation reln, BlockNumber blocknum, char *buffer)
|
|
{
|
|
if (!(*(smgrsw[reln->smgr_which].smgr_read)) (reln, blocknum, buffer))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read block %u of relation %u/%u/%u: %m",
|
|
blocknum,
|
|
reln->smgr_rnode.spcNode,
|
|
reln->smgr_rnode.dbNode,
|
|
reln->smgr_rnode.relNode)));
|
|
}
|
|
|
|
/*
|
|
* smgrwrite() -- Write the supplied buffer out.
|
|
*
|
|
* This is not a synchronous write -- the block is not necessarily
|
|
* on disk at return, only dumped out to the kernel. However,
|
|
* provisions will be made to fsync the write before the next checkpoint.
|
|
*
|
|
* isTemp indicates that the relation is a temp table (ie, is managed
|
|
* by the local-buffer manager). In this case no provisions need be
|
|
* made to fsync the write before checkpointing.
|
|
*/
|
|
void
|
|
smgrwrite(SMgrRelation reln, BlockNumber blocknum, char *buffer, bool isTemp)
|
|
{
|
|
if (!(*(smgrsw[reln->smgr_which].smgr_write)) (reln, blocknum, buffer,
|
|
isTemp))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write block %u of relation %u/%u/%u: %m",
|
|
blocknum,
|
|
reln->smgr_rnode.spcNode,
|
|
reln->smgr_rnode.dbNode,
|
|
reln->smgr_rnode.relNode)));
|
|
}
|
|
|
|
/*
|
|
* smgrnblocks() -- Calculate the number of blocks in the
|
|
* supplied relation.
|
|
*
|
|
* Returns the number of blocks on success, aborts the current
|
|
* transaction on failure.
|
|
*/
|
|
BlockNumber
|
|
smgrnblocks(SMgrRelation reln)
|
|
{
|
|
BlockNumber nblocks;
|
|
|
|
nblocks = (*(smgrsw[reln->smgr_which].smgr_nblocks)) (reln);
|
|
|
|
/*
|
|
* NOTE: if a relation ever did grow to 2^32-1 blocks, this code would
|
|
* fail --- but that's a good thing, because it would stop us from
|
|
* extending the rel another block and having a block whose number
|
|
* actually is InvalidBlockNumber.
|
|
*/
|
|
if (nblocks == InvalidBlockNumber)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not count blocks of relation %u/%u/%u: %m",
|
|
reln->smgr_rnode.spcNode,
|
|
reln->smgr_rnode.dbNode,
|
|
reln->smgr_rnode.relNode)));
|
|
|
|
return nblocks;
|
|
}
|
|
|
|
/*
|
|
* smgrtruncate() -- Truncate supplied relation to the specified number
|
|
* of blocks
|
|
*
|
|
* Returns the number of blocks on success, aborts the current
|
|
* transaction on failure.
|
|
*/
|
|
BlockNumber
|
|
smgrtruncate(SMgrRelation reln, BlockNumber nblocks, bool isTemp)
|
|
{
|
|
BlockNumber newblks;
|
|
|
|
/*
|
|
* Get rid of any buffers for the about-to-be-deleted blocks.
|
|
* bufmgr will just drop them without bothering to write the contents.
|
|
*/
|
|
DropRelFileNodeBuffers(reln->smgr_rnode, isTemp, nblocks);
|
|
|
|
/*
|
|
* Tell the free space map to forget anything it may have stored for
|
|
* the about-to-be-deleted blocks. We want to be sure it won't return
|
|
* bogus block numbers later on.
|
|
*/
|
|
FreeSpaceMapTruncateRel(&reln->smgr_rnode, nblocks);
|
|
|
|
/* Do the truncation */
|
|
newblks = (*(smgrsw[reln->smgr_which].smgr_truncate)) (reln, nblocks,
|
|
isTemp);
|
|
if (newblks == InvalidBlockNumber)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not truncate relation %u/%u/%u to %u blocks: %m",
|
|
reln->smgr_rnode.spcNode,
|
|
reln->smgr_rnode.dbNode,
|
|
reln->smgr_rnode.relNode,
|
|
nblocks)));
|
|
|
|
if (!isTemp)
|
|
{
|
|
/*
|
|
* Make a non-transactional XLOG entry showing the file
|
|
* truncation. It's non-transactional because we should replay it
|
|
* whether the transaction commits or not; the underlying file
|
|
* change is certainly not reversible.
|
|
*/
|
|
XLogRecPtr lsn;
|
|
XLogRecData rdata;
|
|
xl_smgr_truncate xlrec;
|
|
|
|
xlrec.blkno = newblks;
|
|
xlrec.rnode = reln->smgr_rnode;
|
|
|
|
rdata.buffer = InvalidBuffer;
|
|
rdata.data = (char *) &xlrec;
|
|
rdata.len = sizeof(xlrec);
|
|
rdata.next = NULL;
|
|
|
|
lsn = XLogInsert(RM_SMGR_ID, XLOG_SMGR_TRUNCATE | XLOG_NO_TRAN,
|
|
&rdata);
|
|
}
|
|
|
|
return newblks;
|
|
}
|
|
|
|
/*
|
|
* smgrimmedsync() -- Force the specified relation to stable storage.
|
|
*
|
|
* Synchronously force all of the specified relation down to disk.
|
|
*
|
|
* This is useful for building completely new relations (eg, new
|
|
* indexes). Instead of incrementally WAL-logging the index build
|
|
* steps, we can just write completed index pages to disk with smgrwrite
|
|
* or smgrextend, and then fsync the completed index file before
|
|
* committing the transaction. (This is sufficient for purposes of
|
|
* crash recovery, since it effectively duplicates forcing a checkpoint
|
|
* for the completed index. But it is *not* sufficient if one wishes
|
|
* to use the WAL log for PITR or replication purposes: in that case
|
|
* we have to make WAL entries as well.)
|
|
*
|
|
* The preceding writes should specify isTemp = true to avoid
|
|
* duplicative fsyncs.
|
|
*/
|
|
void
|
|
smgrimmedsync(SMgrRelation reln)
|
|
{
|
|
if (!(*(smgrsw[reln->smgr_which].smgr_immedsync)) (reln))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not sync relation %u/%u/%u: %m",
|
|
reln->smgr_rnode.spcNode,
|
|
reln->smgr_rnode.dbNode,
|
|
reln->smgr_rnode.relNode)));
|
|
}
|
|
|
|
/*
|
|
* smgrDoPendingDeletes() -- Take care of relation deletes at end of xact.
|
|
*
|
|
* This also runs when aborting a subxact; we want to clean up a failed
|
|
* subxact immediately.
|
|
*/
|
|
void
|
|
smgrDoPendingDeletes(bool isCommit)
|
|
{
|
|
int nestLevel = GetCurrentTransactionNestLevel();
|
|
PendingRelDelete *pending;
|
|
PendingRelDelete *prev;
|
|
PendingRelDelete *next;
|
|
|
|
prev = NULL;
|
|
for (pending = pendingDeletes; pending != NULL; pending = next)
|
|
{
|
|
next = pending->next;
|
|
if (pending->nestLevel < nestLevel)
|
|
{
|
|
/* outer-level entries should not be processed yet */
|
|
prev = pending;
|
|
}
|
|
else
|
|
{
|
|
/* unlink list entry first, so we don't retry on failure */
|
|
if (prev)
|
|
prev->next = next;
|
|
else
|
|
pendingDeletes = next;
|
|
/* do deletion if called for */
|
|
if (pending->atCommit == isCommit)
|
|
smgr_internal_unlink(pending->relnode,
|
|
pending->which,
|
|
pending->isTemp,
|
|
false);
|
|
/* must explicitly free the list entry */
|
|
pfree(pending);
|
|
/* prev does not change */
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* smgrGetPendingDeletes() -- Get a list of relations to be deleted.
|
|
*
|
|
* The return value is the number of relations scheduled for termination.
|
|
* *ptr is set to point to a freshly-palloc'd array of RelFileNodes.
|
|
* If there are no relations to be deleted, *ptr is set to NULL.
|
|
*
|
|
* Note that the list does not include anything scheduled for termination
|
|
* by upper-level transactions.
|
|
*/
|
|
int
|
|
smgrGetPendingDeletes(bool forCommit, RelFileNode **ptr)
|
|
{
|
|
int nestLevel = GetCurrentTransactionNestLevel();
|
|
int nrels;
|
|
RelFileNode *rptr;
|
|
PendingRelDelete *pending;
|
|
|
|
nrels = 0;
|
|
for (pending = pendingDeletes; pending != NULL; pending = pending->next)
|
|
{
|
|
if (pending->nestLevel >= nestLevel && pending->atCommit == forCommit)
|
|
nrels++;
|
|
}
|
|
if (nrels == 0)
|
|
{
|
|
*ptr = NULL;
|
|
return 0;
|
|
}
|
|
rptr = (RelFileNode *) palloc(nrels * sizeof(RelFileNode));
|
|
*ptr = rptr;
|
|
for (pending = pendingDeletes; pending != NULL; pending = pending->next)
|
|
{
|
|
if (pending->nestLevel >= nestLevel && pending->atCommit == forCommit)
|
|
*rptr++ = pending->relnode;
|
|
}
|
|
return nrels;
|
|
}
|
|
|
|
/*
|
|
* AtSubCommit_smgr() --- Take care of subtransaction commit.
|
|
*
|
|
* Reassign all items in the pending-deletes list to the parent transaction.
|
|
*/
|
|
void
|
|
AtSubCommit_smgr(void)
|
|
{
|
|
int nestLevel = GetCurrentTransactionNestLevel();
|
|
PendingRelDelete *pending;
|
|
|
|
for (pending = pendingDeletes; pending != NULL; pending = pending->next)
|
|
{
|
|
if (pending->nestLevel >= nestLevel)
|
|
pending->nestLevel = nestLevel - 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* AtSubAbort_smgr() --- Take care of subtransaction abort.
|
|
*
|
|
* Delete created relations and forget about deleted relations.
|
|
* We can execute these operations immediately because we know this
|
|
* subtransaction will not commit.
|
|
*/
|
|
void
|
|
AtSubAbort_smgr(void)
|
|
{
|
|
smgrDoPendingDeletes(false);
|
|
}
|
|
|
|
/*
|
|
* smgrcommit() -- Prepare to commit changes made during the current
|
|
* transaction.
|
|
*
|
|
* This is called before we actually commit.
|
|
*/
|
|
void
|
|
smgrcommit(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NSmgr; i++)
|
|
{
|
|
if (smgrsw[i].smgr_commit)
|
|
{
|
|
if (!(*(smgrsw[i].smgr_commit)) ())
|
|
elog(ERROR, "transaction commit failed on %s: %m",
|
|
DatumGetCString(DirectFunctionCall1(smgrout,
|
|
Int16GetDatum(i))));
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* smgrabort() -- Clean up after transaction abort.
|
|
*/
|
|
void
|
|
smgrabort(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NSmgr; i++)
|
|
{
|
|
if (smgrsw[i].smgr_abort)
|
|
{
|
|
if (!(*(smgrsw[i].smgr_abort)) ())
|
|
elog(ERROR, "transaction abort failed on %s: %m",
|
|
DatumGetCString(DirectFunctionCall1(smgrout,
|
|
Int16GetDatum(i))));
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* smgrsync() -- Sync files to disk at checkpoint time.
|
|
*/
|
|
void
|
|
smgrsync(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NSmgr; i++)
|
|
{
|
|
if (smgrsw[i].smgr_sync)
|
|
{
|
|
if (!(*(smgrsw[i].smgr_sync)) ())
|
|
elog(ERROR, "storage sync failed on %s: %m",
|
|
DatumGetCString(DirectFunctionCall1(smgrout,
|
|
Int16GetDatum(i))));
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
void
|
|
smgr_redo(XLogRecPtr lsn, XLogRecord *record)
|
|
{
|
|
uint8 info = record->xl_info & ~XLR_INFO_MASK;
|
|
|
|
if (info == XLOG_SMGR_CREATE)
|
|
{
|
|
xl_smgr_create *xlrec = (xl_smgr_create *) XLogRecGetData(record);
|
|
SMgrRelation reln;
|
|
|
|
reln = smgropen(xlrec->rnode);
|
|
smgrcreate(reln, false, true);
|
|
}
|
|
else if (info == XLOG_SMGR_TRUNCATE)
|
|
{
|
|
xl_smgr_truncate *xlrec = (xl_smgr_truncate *) XLogRecGetData(record);
|
|
SMgrRelation reln;
|
|
BlockNumber newblks;
|
|
|
|
reln = smgropen(xlrec->rnode);
|
|
|
|
/* Can't use smgrtruncate because it would try to xlog */
|
|
|
|
/*
|
|
* First, force bufmgr to drop any buffers it has for the to-be-
|
|
* truncated blocks. We must do this, else subsequent
|
|
* XLogReadBuffer operations will not re-extend the file properly.
|
|
*/
|
|
DropRelFileNodeBuffers(xlrec->rnode, false, xlrec->blkno);
|
|
|
|
/*
|
|
* Tell the free space map to forget anything it may have stored
|
|
* for the about-to-be-deleted blocks. We want to be sure it
|
|
* won't return bogus block numbers later on.
|
|
*/
|
|
FreeSpaceMapTruncateRel(&reln->smgr_rnode, xlrec->blkno);
|
|
|
|
/* Do the truncation */
|
|
newblks = (*(smgrsw[reln->smgr_which].smgr_truncate)) (reln,
|
|
xlrec->blkno,
|
|
false);
|
|
if (newblks == InvalidBlockNumber)
|
|
ereport(WARNING,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not truncate relation %u/%u/%u to %u blocks: %m",
|
|
reln->smgr_rnode.spcNode,
|
|
reln->smgr_rnode.dbNode,
|
|
reln->smgr_rnode.relNode,
|
|
xlrec->blkno)));
|
|
}
|
|
else
|
|
elog(PANIC, "smgr_redo: unknown op code %u", info);
|
|
}
|
|
|
|
void
|
|
smgr_undo(XLogRecPtr lsn, XLogRecord *record)
|
|
{
|
|
/* Since we have no transactional WAL entries, should never undo */
|
|
elog(PANIC, "smgr_undo: cannot undo");
|
|
}
|
|
|
|
void
|
|
smgr_desc(char *buf, uint8 xl_info, char *rec)
|
|
{
|
|
uint8 info = xl_info & ~XLR_INFO_MASK;
|
|
|
|
if (info == XLOG_SMGR_CREATE)
|
|
{
|
|
xl_smgr_create *xlrec = (xl_smgr_create *) rec;
|
|
|
|
sprintf(buf + strlen(buf), "file create: %u/%u/%u",
|
|
xlrec->rnode.spcNode, xlrec->rnode.dbNode,
|
|
xlrec->rnode.relNode);
|
|
}
|
|
else if (info == XLOG_SMGR_TRUNCATE)
|
|
{
|
|
xl_smgr_truncate *xlrec = (xl_smgr_truncate *) rec;
|
|
|
|
sprintf(buf + strlen(buf), "file truncate: %u/%u/%u to %u blocks",
|
|
xlrec->rnode.spcNode, xlrec->rnode.dbNode,
|
|
xlrec->rnode.relNode, xlrec->blkno);
|
|
}
|
|
else
|
|
strcat(buf, "UNKNOWN");
|
|
}
|