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908 lines
24 KiB
C
908 lines
24 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) 1996-2007, 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 1.108 2007/11/15 21:14:38 momjian 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 "access/xlogutils.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 report problems via elog(ERROR). An exception is
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* that smgr_unlink should use elog(WARNING), rather than erroring out,
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* because we normally unlink relations during post-commit/abort cleanup,
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* and so it's too late to raise an error. Also, various conditions that
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* would normally be errors should be allowed during bootstrap and/or WAL
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* recovery --- see comments in md.c for details.
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*/
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typedef struct f_smgr
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{
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void (*smgr_init) (void); /* may be NULL */
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void (*smgr_shutdown) (void); /* may be NULL */
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void (*smgr_close) (SMgrRelation reln);
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void (*smgr_create) (SMgrRelation reln, bool isRedo);
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void (*smgr_unlink) (RelFileNode rnode, bool isRedo);
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void (*smgr_extend) (SMgrRelation reln, BlockNumber blocknum,
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char *buffer, bool isTemp);
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void (*smgr_read) (SMgrRelation reln, BlockNumber blocknum,
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char *buffer);
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void (*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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void (*smgr_truncate) (SMgrRelation reln, BlockNumber nblocks,
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bool isTemp);
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void (*smgr_immedsync) (SMgrRelation reln);
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void (*smgr_commit) (void); /* may be NULL */
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void (*smgr_abort) (void); /* may be NULL */
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void (*smgr_pre_ckpt) (void); /* may be NULL */
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void (*smgr_sync) (void); /* may be NULL */
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void (*smgr_post_ckpt) (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, mdpreckpt, mdsync, mdpostckpt
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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 storage
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* managers.
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*
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* Note: smgrinit is called during backend startup (normal or standalone
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* case), *not* during postmaster start. Therefore, any resources created
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* here or destroyed in smgrshutdown are backend-local.
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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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(*(smgrsw[i].smgr_init)) ();
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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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/*
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* on_proc_exit hook for smgr cleanup during backend shutdown
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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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(*(smgrsw[i].smgr_shutdown)) ();
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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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/* 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 it
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* 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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(*(smgrsw[reln->smgr_which].smgr_close)) (reln);
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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 remote
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* possibility of failure above, the SMgrRelation object will still 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 TablespaceCreateDbspace
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* should be here and not in commands/tablespace.c? But that would imply
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* importing a lot of 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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(*(smgrsw[reln->smgr_which].smgr_create)) (reln, isRedo);
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if (isRedo)
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return;
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/*
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* Make an XLOG entry showing the file creation. If we abort, the file
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* will be dropped at abort time.
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*/
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xlrec.rnode = reln->smgr_rnode;
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rdata.data = (char *) &xlrec;
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rdata.len = sizeof(xlrec);
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rdata.buffer = InvalidBuffer;
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rdata.next = NULL;
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lsn = XLogInsert(RM_SMGR_ID, XLOG_SMGR_CREATE, &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 be
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* present in the pending-delete list twice, once with atCommit true and
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* once with atCommit false. Hence, it will be physically deleted at end
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* of xact in either case (and the other entry will be ignored by
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* smgrDoPendingDeletes, so no error will occur). We could instead remove
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* the existing list entry and delete the physical file immediately, but
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* 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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* 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.
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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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* 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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* Tell the free space map to forget this relation. It won't be accessed
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* any more anyway, but we may as well recycle the map space quickly.
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*/
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FreeSpaceMapForgetRel(&rnode);
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/*
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* It'd be nice to tell the stats collector to forget it immediately, too.
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* But we can't because we don't know the OID (and in cases involving
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* relfilenode swaps, it's not always clear which table OID to forget,
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* anyway).
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*/
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/*
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* And delete the physical files.
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*
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* Note: smgr_unlink must treat deletion failure as a WARNING, not an
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* ERROR, because we've already decided to commit or abort the current
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* xact.
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*/
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(*(smgrsw[which].smgr_unlink)) (rnode, isRedo);
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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 nearly the same as smgrwrite(): write at the
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* specified position. However, this is to be used for the case of
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* extending a relation (i.e., blocknum is at or beyond the current
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* EOF). Note that we assume writing a block beyond current EOF
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* causes intervening file space to become filled with zeroes.
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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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{
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(*(smgrsw[reln->smgr_which].smgr_extend)) (reln, blocknum, buffer, isTemp);
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}
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/*
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* smgrread() -- read a particular block from a relation into the supplied
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* buffer.
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*
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* This routine is called from the buffer manager in order to
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* instantiate pages in the shared buffer cache. All storage managers
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* return pages in the format that POSTGRES expects.
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*/
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void
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smgrread(SMgrRelation reln, BlockNumber blocknum, char *buffer)
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{
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(*(smgrsw[reln->smgr_which].smgr_read)) (reln, blocknum, buffer);
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}
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/*
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* smgrwrite() -- Write the supplied buffer out.
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*
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* This is to be used only for updating already-existing blocks of a
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* relation (ie, those before the current EOF). To extend a relation,
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* use smgrextend().
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*
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* This is not a synchronous write -- the block is not necessarily
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* on disk at return, only dumped out to the kernel. However,
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* provisions will be made to fsync the write before the next checkpoint.
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*
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* isTemp indicates that the relation is a temp table (ie, is managed
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* by the local-buffer manager). In this case no provisions need be
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* made to fsync the write before checkpointing.
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*/
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void
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|
smgrwrite(SMgrRelation reln, BlockNumber blocknum, char *buffer, bool isTemp)
|
|
{
|
|
(*(smgrsw[reln->smgr_which].smgr_write)) (reln, blocknum, buffer, isTemp);
|
|
}
|
|
|
|
/*
|
|
* smgrnblocks() -- Calculate the number of blocks in the
|
|
* supplied relation.
|
|
*/
|
|
BlockNumber
|
|
smgrnblocks(SMgrRelation reln)
|
|
{
|
|
return (*(smgrsw[reln->smgr_which].smgr_nblocks)) (reln);
|
|
}
|
|
|
|
/*
|
|
* smgrtruncate() -- Truncate supplied relation to the specified number
|
|
* of blocks
|
|
*/
|
|
void
|
|
smgrtruncate(SMgrRelation reln, BlockNumber nblocks, bool isTemp)
|
|
{
|
|
/*
|
|
* 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 */
|
|
(*(smgrsw[reln->smgr_which].smgr_truncate)) (reln, nblocks, isTemp);
|
|
|
|
if (!isTemp)
|
|
{
|
|
/*
|
|
* Make an XLOG entry showing the file truncation.
|
|
*/
|
|
XLogRecPtr lsn;
|
|
XLogRecData rdata;
|
|
xl_smgr_truncate xlrec;
|
|
|
|
xlrec.blkno = nblocks;
|
|
xlrec.rnode = reln->smgr_rnode;
|
|
|
|
rdata.data = (char *) &xlrec;
|
|
rdata.len = sizeof(xlrec);
|
|
rdata.buffer = InvalidBuffer;
|
|
rdata.next = NULL;
|
|
|
|
lsn = XLogInsert(RM_SMGR_ID, XLOG_SMGR_TRUNCATE, &rdata);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* smgrimmedsync() -- Force the specified relation to stable storage.
|
|
*
|
|
* Synchronously force all previous writes to 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.
|
|
*
|
|
* Note that you need to do FlushRelationBuffers() first if there is
|
|
* any possibility that there are dirty buffers for the relation;
|
|
* otherwise the sync is not very meaningful.
|
|
*/
|
|
void
|
|
smgrimmedsync(SMgrRelation reln)
|
|
{
|
|
(*(smgrsw[reln->smgr_which].smgr_immedsync)) (reln);
|
|
}
|
|
|
|
|
|
/*
|
|
* PostPrepare_smgr -- Clean up after a successful PREPARE
|
|
*
|
|
* What we have to do here is throw away the in-memory state about pending
|
|
* relation deletes. It's all been recorded in the 2PC state file and
|
|
* it's no longer smgr's job to worry about it.
|
|
*/
|
|
void
|
|
PostPrepare_smgr(void)
|
|
{
|
|
PendingRelDelete *pending;
|
|
PendingRelDelete *next;
|
|
|
|
for (pending = pendingDeletes; pending != NULL; pending = next)
|
|
{
|
|
next = pending->next;
|
|
pendingDeletes = next;
|
|
/* must explicitly free the list entry */
|
|
pfree(pending);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* If haveNonTemp isn't NULL, the bool it points to gets set to true if
|
|
* there is any non-temp table pending to be deleted; false if not.
|
|
*
|
|
* Note that the list does not include anything scheduled for termination
|
|
* by upper-level transactions.
|
|
*/
|
|
int
|
|
smgrGetPendingDeletes(bool forCommit, RelFileNode **ptr, bool *haveNonTemp)
|
|
{
|
|
int nestLevel = GetCurrentTransactionNestLevel();
|
|
int nrels;
|
|
RelFileNode *rptr;
|
|
PendingRelDelete *pending;
|
|
|
|
nrels = 0;
|
|
if (haveNonTemp)
|
|
*haveNonTemp = false;
|
|
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;
|
|
if (haveNonTemp && !pending->isTemp)
|
|
*haveNonTemp = true;
|
|
}
|
|
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)
|
|
(*(smgrsw[i].smgr_commit)) ();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* smgrabort() -- Clean up after transaction abort.
|
|
*/
|
|
void
|
|
smgrabort(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NSmgr; i++)
|
|
{
|
|
if (smgrsw[i].smgr_abort)
|
|
(*(smgrsw[i].smgr_abort)) ();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* smgrpreckpt() -- Prepare for checkpoint.
|
|
*/
|
|
void
|
|
smgrpreckpt(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NSmgr; i++)
|
|
{
|
|
if (smgrsw[i].smgr_pre_ckpt)
|
|
(*(smgrsw[i].smgr_pre_ckpt)) ();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* smgrsync() -- Sync files to disk during checkpoint.
|
|
*/
|
|
void
|
|
smgrsync(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NSmgr; i++)
|
|
{
|
|
if (smgrsw[i].smgr_sync)
|
|
(*(smgrsw[i].smgr_sync)) ();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* smgrpostckpt() -- Post-checkpoint cleanup.
|
|
*/
|
|
void
|
|
smgrpostckpt(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NSmgr; i++)
|
|
{
|
|
if (smgrsw[i].smgr_post_ckpt)
|
|
(*(smgrsw[i].smgr_post_ckpt)) ();
|
|
}
|
|
}
|
|
|
|
|
|
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;
|
|
|
|
reln = smgropen(xlrec->rnode);
|
|
|
|
/*
|
|
* Forcibly create relation if it doesn't exist (which suggests that
|
|
* it was dropped somewhere later in the WAL sequence). As in
|
|
* XLogOpenRelation, we prefer to recreate the rel and replay the log
|
|
* as best we can until the drop is seen.
|
|
*/
|
|
smgrcreate(reln, false, true);
|
|
|
|
/* 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 */
|
|
(*(smgrsw[reln->smgr_which].smgr_truncate)) (reln,
|
|
xlrec->blkno,
|
|
false);
|
|
|
|
/* Also tell xlogutils.c about it */
|
|
XLogTruncateRelation(xlrec->rnode, xlrec->blkno);
|
|
}
|
|
else
|
|
elog(PANIC, "smgr_redo: unknown op code %u", info);
|
|
}
|
|
|
|
void
|
|
smgr_desc(StringInfo 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;
|
|
|
|
appendStringInfo(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;
|
|
|
|
appendStringInfo(buf, "file truncate: %u/%u/%u to %u blocks",
|
|
xlrec->rnode.spcNode, xlrec->rnode.dbNode,
|
|
xlrec->rnode.relNode, xlrec->blkno);
|
|
}
|
|
else
|
|
appendStringInfo(buf, "UNKNOWN");
|
|
}
|