fd.h File Reference

#include <dirent.h>

Include dependency graph for fd.h:

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Go to the source code of this file.

Macros
#define	FILE_POSSIBLY_DELETED(err)   ((err) == ENOENT)
#define	PG_TEMP_FILES_DIR   "pgsql_tmp"
#define	PG_TEMP_FILE_PREFIX   "pgsql_tmp"

Typedefs
typedef int	File

Functions
File	PathNameOpenFile (const char *fileName, int fileFlags)
File	PathNameOpenFilePerm (const char *fileName, int fileFlags, mode_t fileMode)
File	OpenTemporaryFile (bool interXact)
void	FileClose (File file)
int	FilePrefetch (File file, off_t offset, int amount, uint32 wait_event_info)
int	FileRead (File file, char *buffer, int amount, off_t offset, uint32 wait_event_info)
int	FileWrite (File file, char *buffer, int amount, off_t offset, uint32 wait_event_info)
int	FileSync (File file, uint32 wait_event_info)
off_t	FileSize (File file)
int	FileTruncate (File file, off_t offset, uint32 wait_event_info)
void	FileWriteback (File file, off_t offset, off_t nbytes, uint32 wait_event_info)
char *	FilePathName (File file)
int	FileGetRawDesc (File file)
int	FileGetRawFlags (File file)
mode_t	FileGetRawMode (File file)
File	PathNameCreateTemporaryFile (const char *name, bool error_on_failure)
File	PathNameOpenTemporaryFile (const char *path, int mode)
bool	PathNameDeleteTemporaryFile (const char *name, bool error_on_failure)
void	PathNameCreateTemporaryDir (const char *base, const char *name)
void	PathNameDeleteTemporaryDir (const char *name)
void	TempTablespacePath (char *path, Oid tablespace)
FILE *	AllocateFile (const char *name, const char *mode)
int	FreeFile (FILE *file)
FILE *	OpenPipeStream (const char *command, const char *mode)
int	ClosePipeStream (FILE *file)
DIR *	AllocateDir (const char *dirname)
struct dirent *	ReadDir (DIR *dir, const char *dirname)
struct dirent *	ReadDirExtended (DIR *dir, const char *dirname, int elevel)
int	FreeDir (DIR *dir)
int	OpenTransientFile (const char *fileName, int fileFlags)
int	OpenTransientFilePerm (const char *fileName, int fileFlags, mode_t fileMode)
int	CloseTransientFile (int fd)
int	BasicOpenFile (const char *fileName, int fileFlags)
int	BasicOpenFilePerm (const char *fileName, int fileFlags, mode_t fileMode)
bool	AcquireExternalFD (void)
void	ReserveExternalFD (void)
void	ReleaseExternalFD (void)
int	MakePGDirectory (const char *directoryName)
void	InitFileAccess (void)
void	set_max_safe_fds (void)
void	closeAllVfds (void)
void	SetTempTablespaces (Oid *tableSpaces, int numSpaces)
bool	TempTablespacesAreSet (void)
int	GetTempTablespaces (Oid *tableSpaces, int numSpaces)
Oid	GetNextTempTableSpace (void)
void	AtEOXact_Files (bool isCommit)
void	AtEOSubXact_Files (bool isCommit, SubTransactionId mySubid, SubTransactionId parentSubid)
void	RemovePgTempFiles (void)
void	RemovePgTempFilesInDir (const char *tmpdirname, bool missing_ok, bool unlink_all)
bool	looks_like_temp_rel_name (const char *name)
int	pg_fsync (int fd)
int	pg_fsync_no_writethrough (int fd)
int	pg_fsync_writethrough (int fd)
int	pg_fdatasync (int fd)
void	pg_flush_data (int fd, off_t offset, off_t amount)
ssize_t	pg_pwritev_with_retry (int fd, const struct iovec *iov, int iovcnt, off_t offset)
int	pg_truncate (const char *path, off_t length)
void	fsync_fname (const char *fname, bool isdir)
int	fsync_fname_ext (const char *fname, bool isdir, bool ignore_perm, int elevel)
int	durable_rename (const char *oldfile, const char *newfile, int loglevel)
int	durable_unlink (const char *fname, int loglevel)
int	durable_rename_excl (const char *oldfile, const char *newfile, int loglevel)
void	SyncDataDirectory (void)
int	data_sync_elevel (int elevel)

Variables
PGDLLIMPORT int	max_files_per_process
PGDLLIMPORT bool	data_sync_retry
int	max_safe_fds

Macro Definition Documentation

FILE_POSSIBLY_DELETED

#define FILE_POSSIBLY_DELETED

(

err

)

((err) == ENOENT)

Definition at line 70 of file fd.h.

Referenced by _mdfd_getseg(), mdopenfork(), and ProcessSyncRequests().

PG_TEMP_FILE_PREFIX

#define PG_TEMP_FILE_PREFIX   "pgsql_tmp"

Definition at line 172 of file fd.h.

PG_TEMP_FILES_DIR

#define PG_TEMP_FILES_DIR   "pgsql_tmp"

Definition at line 171 of file fd.h.

Typedef Documentation

File

typedef int File

Definition at line 48 of file fd.h.

Function Documentation

AcquireExternalFD()

bool AcquireExternalFD

(

void

)

Definition at line 1076 of file fd.c.

References max_safe_fds, numExternalFDs, and ReserveExternalFD().

Referenced by connect_pg_server(), CreateWaitEventSet(), dblink_connect(), and dblink_get_conn().

{
    /*
     * We don't want more than max_safe_fds / 3 FDs to be consumed for
     * "external" FDs.
     */
    if (numExternalFDs < max_safe_fds / 3)
    {
        ReserveExternalFD();
        return true;
    }
    errno = EMFILE;
    return false;
}

AllocateDir()

DIR* AllocateDir

(

const char *

dirname

)

Definition at line 2615 of file fd.c.

References AllocateDescDir, AllocateDesc::create_subid, AllocateDesc::desc, AllocateDesc::dir, DO_DB, elog, ereport, errcode(), errmsg(), ERROR, GetCurrentSubTransactionId(), AllocateDesc::kind, LOG, maxAllocatedDescs, numAllocatedDescs, opendir(), ReleaseLruFile(), ReleaseLruFiles(), and reserveAllocatedDesc().

Referenced by calculate_database_size(), calculate_tablespace_size(), CheckPointLogicalRewriteHeap(), CheckPointSnapBuild(), CleanupBackupHistory(), copydir(), db_dir_size(), DeleteAllExportedSnapshotFiles(), destroy_tablespace_directories(), directory_is_empty(), do_pg_start_backup(), dsm_cleanup_for_mmap(), extension_file_exists(), get_ext_ver_list(), getInstallationPaths(), movedb(), ParseTzFile(), perform_base_backup(), pg_available_extension_versions(), pg_available_extensions(), pg_logdir_ls_internal(), pg_ls_dir(), pg_ls_dir_files(), pg_tablespace_databases(), pg_tzenumerate_next(), pg_tzenumerate_start(), pgarch_readyXlog(), pgstat_reset_remove_files(), RelationCacheInitFileRemove(), RelationCacheInitFileRemoveInDir(), RemoveNonParentXlogFiles(), RemoveOldXlogFiles(), RemovePgTempFiles(), RemovePgTempFilesInDir(), RemovePgTempRelationFiles(), RemovePgTempRelationFilesInDbspace(), RemoveTempXlogFiles(), ReorderBufferCleanupSerializedTXNs(), ResetUnloggedRelations(), ResetUnloggedRelationsInDbspaceDir(), ResetUnloggedRelationsInTablespaceDir(), restoreTwoPhaseData(), scan_directory_ci(), sendDir(), SlruScanDirectory(), StartupReorderBuffer(), StartupReplicationSlots(), UpdateLogicalMappings(), and walkdir().

{
    DIR        *dir;

    DO_DB(elog(LOG, "AllocateDir: Allocated %d (%s)",
               numAllocatedDescs, dirname));

    /* Can we allocate another non-virtual FD? */
    if (!reserveAllocatedDesc())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
                 errmsg("exceeded maxAllocatedDescs (%d) while trying to open directory \"%s\"",
                        maxAllocatedDescs, dirname)));

    /* Close excess kernel FDs. */
    ReleaseLruFiles();

TryAgain:
    if ((dir = opendir(dirname)) != NULL)
    {
        AllocateDesc *desc = &allocatedDescs[numAllocatedDescs];

        desc->kind = AllocateDescDir;
        desc->desc.dir = dir;
        desc->create_subid = GetCurrentSubTransactionId();
        numAllocatedDescs++;
        return desc->desc.dir;
    }

    if (errno == EMFILE || errno == ENFILE)
    {
        int         save_errno = errno;

        ereport(LOG,
                (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
                 errmsg("out of file descriptors: %m; release and retry")));
        errno = 0;
        if (ReleaseLruFile())
            goto TryAgain;
        errno = save_errno;
    }

    return NULL;
}

AllocateFile()

FILE* AllocateFile	(	const char *	name,
		const char *	mode
	)

Definition at line 2354 of file fd.c.

References AllocateDescFile, AllocateDesc::create_subid, AllocateDesc::desc, DO_DB, elog, ereport, errcode(), errmsg(), ERROR, AllocateDesc::file, GetCurrentSubTransactionId(), AllocateDesc::kind, LOG, maxAllocatedDescs, numAllocatedDescs, ReleaseLruFile(), ReleaseLruFiles(), and reserveAllocatedDesc().

Referenced by _ShowOption(), AlterSystemSetConfigFile(), apw_dump_now(), apw_load_buffers(), BackendRun(), BeginCopyFrom(), BeginCopyTo(), checkControlFile(), do_pg_start_backup(), do_pg_stop_backup(), entry_reset(), existsTimeLineHistory(), ExportSnapshot(), fill_hba_view(), gc_qtexts(), ImportSnapshot(), load_dh_file(), load_hba(), load_ident(), load_relcache_init_file(), parse_extension_control_file(), ParseTzFile(), pg_backup_start_time(), pg_current_logfile(), pg_file_write_internal(), pg_promote(), PGSharedMemoryAttach(), pgss_shmem_shutdown(), pgss_shmem_startup(), pgstat_read_db_statsfile(), pgstat_read_db_statsfile_timestamp(), pgstat_read_statsfiles(), pgstat_write_db_statsfile(), pgstat_write_statsfiles(), PostmasterMarkPIDForWorkerNotify(), read_backup_label(), read_binary_file(), read_tablespace_map(), read_whole_file(), readTimeLineHistory(), tokenize_inc_file(), tsearch_readline_begin(), ValidatePgVersion(), write_relcache_init_file(), XLogArchiveForceDone(), and XLogArchiveNotify().

{
    FILE       *file;

    DO_DB(elog(LOG, "AllocateFile: Allocated %d (%s)",
               numAllocatedDescs, name));

    /* Can we allocate another non-virtual FD? */
    if (!reserveAllocatedDesc())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
                 errmsg("exceeded maxAllocatedDescs (%d) while trying to open file \"%s\"",
                        maxAllocatedDescs, name)));

    /* Close excess kernel FDs. */
    ReleaseLruFiles();

TryAgain:
    if ((file = fopen(name, mode)) != NULL)
    {
        AllocateDesc *desc = &allocatedDescs[numAllocatedDescs];

        desc->kind = AllocateDescFile;
        desc->desc.file = file;
        desc->create_subid = GetCurrentSubTransactionId();
        numAllocatedDescs++;
        return desc->desc.file;
    }

    if (errno == EMFILE || errno == ENFILE)
    {
        int         save_errno = errno;

        ereport(LOG,
                (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
                 errmsg("out of file descriptors: %m; release and retry")));
        errno = 0;
        if (ReleaseLruFile())
            goto TryAgain;
        errno = save_errno;
    }

    return NULL;
}

AtEOSubXact_Files()

void AtEOSubXact_Files	(	bool	isCommit,
		SubTransactionId	mySubid,
		SubTransactionId	parentSubid
	)

Definition at line 2903 of file fd.c.

References AllocateDesc::create_subid, FreeDesc(), i, and numAllocatedDescs.

Referenced by AbortSubTransaction(), and CommitSubTransaction().

{
    Index       i;

    for (i = 0; i < numAllocatedDescs; i++)
    {
        if (allocatedDescs[i].create_subid == mySubid)
        {
            if (isCommit)
                allocatedDescs[i].create_subid = parentSubid;
            else
            {
                /* have to recheck the item after FreeDesc (ugly) */
                FreeDesc(&allocatedDescs[i--]);
            }
        }
    }
}

AtEOXact_Files()

void AtEOXact_Files

(

bool

isCommit

)

Definition at line 2936 of file fd.c.

References CleanupTempFiles(), numTempTableSpaces, and tempTableSpaces.

Referenced by AbortTransaction(), AutoVacLauncherMain(), BackgroundWriterMain(), CheckpointerMain(), CommitTransaction(), PrepareTransaction(), and WalWriterMain().

{
    CleanupTempFiles(isCommit, false);
    tempTableSpaces = NULL;
    numTempTableSpaces = -1;
}

BasicOpenFile()

int BasicOpenFile	(	const char *	fileName,
		int	fileFlags
	)

Definition at line 1014 of file fd.c.

References BasicOpenFilePerm(), and pg_file_create_mode.

Referenced by AlterSystemSetConfigFile(), ReadControlFile(), update_controlfile(), wal_segment_open(), WalSndSegmentOpen(), WriteControlFile(), XLogFileInit(), XLogFileOpen(), and XLogFileRead().

{
    return BasicOpenFilePerm(fileName, fileFlags, pg_file_create_mode);
}

BasicOpenFilePerm()

int BasicOpenFilePerm	(	const char *	fileName,
		int	fileFlags,
		mode_t	fileMode
	)

Definition at line 1036 of file fd.c.

References ereport, errcode(), errmsg(), vfd::fd, LOG, and ReleaseLruFile().

Referenced by BasicOpenFile(), LruInsert(), OpenTransientFilePerm(), PathNameOpenFilePerm(), and readRecoverySignalFile().

{
    int         fd;

tryAgain:
    fd = open(fileName, fileFlags, fileMode);

    if (fd >= 0)
        return fd;              /* success! */

    if (errno == EMFILE || errno == ENFILE)
    {
        int         save_errno = errno;

        ereport(LOG,
                (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
                 errmsg("out of file descriptors: %m; release and retry")));
        errno = 0;
        if (ReleaseLruFile())
            goto tryAgain;
        errno = save_errno;
    }

    return -1;                  /* failure */
}

closeAllVfds()

void closeAllVfds

(

void

)

Definition at line 2792 of file fd.c.

References Assert, FileIsNotOpen, i, LruDelete(), and SizeVfdCache.

Referenced by standard_ProcessUtility().

{
    Index       i;

    if (SizeVfdCache > 0)
    {
        Assert(FileIsNotOpen(0));   /* Make sure ring not corrupted */
        for (i = 1; i < SizeVfdCache; i++)
        {
            if (!FileIsNotOpen(i))
                LruDelete(i);
        }
    }
}

ClosePipeStream()

int ClosePipeStream

(

FILE *

file

)

Definition at line 2763 of file fd.c.

References AllocateDescPipe, AllocateDesc::desc, DO_DB, elog, AllocateDesc::file, FreeDesc(), i, AllocateDesc::kind, LOG, numAllocatedDescs, and WARNING.

Referenced by ClosePipeFromProgram(), ClosePipeToProgram(), pg_import_system_collations(), and run_ssl_passphrase_command().

{
    int         i;

    DO_DB(elog(LOG, "ClosePipeStream: Allocated %d", numAllocatedDescs));

    /* Remove file from list of allocated files, if it's present */
    for (i = numAllocatedDescs; --i >= 0;)
    {
        AllocateDesc *desc = &allocatedDescs[i];

        if (desc->kind == AllocateDescPipe && desc->desc.file == file)
            return FreeDesc(desc);
    }

    /* Only get here if someone passes us a file not in allocatedDescs */
    elog(WARNING, "file passed to ClosePipeStream was not obtained from OpenPipeStream");

    return pclose(file);
}

CloseTransientFile()

int CloseTransientFile

(

int

fd

)

Definition at line 2581 of file fd.c.

References AllocateDescRawFD, close, AllocateDesc::desc, DO_DB, elog, AllocateDesc::fd, FreeDesc(), i, AllocateDesc::kind, LOG, numAllocatedDescs, and WARNING.

Referenced by ApplyLogicalMappingFile(), be_lo_export(), CheckPointLogicalRewriteHeap(), CheckPointReplicationOrigin(), copy_file(), dsm_impl_mmap(), durable_rename(), fsync_fname_ext(), get_controlfile(), heap_xlog_logical_rewrite(), lo_import_internal(), load_relmap_file(), perform_base_backup(), pg_truncate(), qtext_load_file(), qtext_store(), ReadTwoPhaseFile(), RecreateTwoPhaseFile(), ReorderBufferSerializeChange(), ReorderBufferSerializeTXN(), RestoreSlotFromDisk(), SaveSlotToPath(), sendFile(), SendTimeLineHistory(), SimpleLruDoesPhysicalPageExist(), SimpleLruWriteAll(), SlruInternalWritePage(), SlruPhysicalReadPage(), SlruPhysicalWritePage(), SlruSyncFileTag(), SnapBuildRestore(), SnapBuildSerialize(), StartupReplicationOrigin(), walkdir(), write_relmap_file(), writeTimeLineHistory(), writeTimeLineHistoryFile(), and XLogFileCopy().

{
    int         i;

    DO_DB(elog(LOG, "CloseTransientFile: Allocated %d", numAllocatedDescs));

    /* Remove fd from list of allocated files, if it's present */
    for (i = numAllocatedDescs; --i >= 0;)
    {
        AllocateDesc *desc = &allocatedDescs[i];

        if (desc->kind == AllocateDescRawFD && desc->desc.fd == fd)
            return FreeDesc(desc);
    }

    /* Only get here if someone passes us a file not in allocatedDescs */
    elog(WARNING, "fd passed to CloseTransientFile was not obtained from OpenTransientFile");

    return close(fd);
}

data_sync_elevel()

int data_sync_elevel

(

int

elevel

)

Definition at line 3635 of file fd.c.

References data_sync_retry, elevel, and PANIC.

Referenced by CheckPointLogicalRewriteHeap(), FileClose(), fsync_fname(), heap_xlog_logical_rewrite(), logical_end_heap_rewrite(), LruDelete(), mdimmedsync(), pg_flush_data(), ProcessSyncRequests(), register_dirty_segment(), SlruReportIOError(), write_relmap_file(), writeTimeLineHistory(), writeTimeLineHistoryFile(), and XLogFileCopy().

{
    return data_sync_retry ? elevel : PANIC;
}

durable_rename()

int durable_rename	(	const char *	oldfile,
		const char *	newfile,
		int	loglevel
	)

Definition at line 687 of file fd.c.

References CloseTransientFile(), ereport, errcode_for_file_access(), errmsg(), vfd::fd, fsync_fname_ext(), fsync_parent_path(), OpenTransientFile(), PG_BINARY, and pg_fsync().

Referenced by AlterSystemSetConfigFile(), apw_dump_now(), BaseBackup(), CancelBackup(), CheckPointReplicationOrigin(), dir_close(), KeepFileRestoredFromArchive(), pgarch_archiveDone(), pgss_shmem_shutdown(), StartupXLOG(), and XLogArchiveForceDone().

{
    int         fd;

    /*
     * First fsync the old and target path (if it exists), to ensure that they
     * are properly persistent on disk. Syncing the target file is not
     * strictly necessary, but it makes it easier to reason about crashes;
     * because it's then guaranteed that either source or target file exists
     * after a crash.
     */
    if (fsync_fname_ext(oldfile, false, false, elevel) != 0)
        return -1;

    fd = OpenTransientFile(newfile, PG_BINARY | O_RDWR);
    if (fd < 0)
    {
        if (errno != ENOENT)
        {
            ereport(elevel,
                    (errcode_for_file_access(),
                     errmsg("could not open file \"%s\": %m", newfile)));
            return -1;
        }
    }
    else
    {
        if (pg_fsync(fd) != 0)
        {
            int         save_errno;

            /* close file upon error, might not be in transaction context */
            save_errno = errno;
            CloseTransientFile(fd);
            errno = save_errno;

            ereport(elevel,
                    (errcode_for_file_access(),
                     errmsg("could not fsync file \"%s\": %m", newfile)));
            return -1;
        }

        if (CloseTransientFile(fd) != 0)
        {
            ereport(elevel,
                    (errcode_for_file_access(),
                     errmsg("could not close file \"%s\": %m", newfile)));
            return -1;
        }
    }

    /* Time to do the real deal... */
    if (rename(oldfile, newfile) < 0)
    {
        ereport(elevel,
                (errcode_for_file_access(),
                 errmsg("could not rename file \"%s\" to \"%s\": %m",
                        oldfile, newfile)));
        return -1;
    }

    /*
     * To guarantee renaming the file is persistent, fsync the file with its
     * new name, and its containing directory.
     */
    if (fsync_fname_ext(newfile, false, false, elevel) != 0)
        return -1;

    if (fsync_parent_path(newfile, elevel) != 0)
        return -1;

    return 0;
}

durable_rename_excl()

int durable_rename_excl	(	const char *	oldfile,
		const char *	newfile,
		int	loglevel
	)

Definition at line 814 of file fd.c.

References ereport, errcode_for_file_access(), errmsg(), fsync_fname_ext(), fsync_parent_path(), and link().

Referenced by InstallXLogFileSegment(), writeTimeLineHistory(), and writeTimeLineHistoryFile().

{
    /*
     * Ensure that, if we crash directly after the rename/link, a file with
     * valid contents is moved into place.
     */
    if (fsync_fname_ext(oldfile, false, false, elevel) != 0)
        return -1;

    if (link(oldfile, newfile) < 0)
    {
        ereport(elevel,
                (errcode_for_file_access(),
                 errmsg("could not link file \"%s\" to \"%s\": %m",
                        oldfile, newfile)));
        return -1;
    }
    unlink(oldfile);

    /*
     * Make change persistent in case of an OS crash, both the new entry and
     * its parent directory need to be flushed.
     */
    if (fsync_fname_ext(newfile, false, false, elevel) != 0)
        return -1;

    /* Same for parent directory */
    if (fsync_parent_path(newfile, elevel) != 0)
        return -1;

    return 0;
}

durable_unlink()

int durable_unlink	(	const char *	fname,
		int	loglevel
	)

Definition at line 777 of file fd.c.

References ereport, errcode_for_file_access(), errmsg(), and fsync_parent_path().

Referenced by do_pg_stop_backup(), exitArchiveRecovery(), InstallXLogFileSegment(), and RemoveXlogFile().

{
    if (unlink(fname) < 0)
    {
        ereport(elevel,
                (errcode_for_file_access(),
                 errmsg("could not remove file \"%s\": %m",
                        fname)));
        return -1;
    }

    /*
     * To guarantee that the removal of the file is persistent, fsync its
     * parent directory.
     */
    if (fsync_parent_path(fname, elevel) != 0)
        return -1;

    return 0;
}

FileClose()

void FileClose

(

File

file

)

Definition at line 1854 of file fd.c.

References Assert, close, data_sync_elevel(), Delete(), DO_DB, elog, ereport, errcode_for_file_access(), errmsg(), vfd::fd, FD_DELETE_AT_CLOSE, FD_TEMP_FILE_LIMIT, vfd::fdstate, FileIsNotOpen, FileIsValid, vfd::fileName, vfd::fileSize, FreeVfd(), LOG, nfile, ReportTemporaryFileUsage(), ResourceOwnerForgetFile(), vfd::resowner, stat::st_size, stat, temporary_files_size, and VFD_CLOSED.

Referenced by BufFileClose(), BufFileTruncateShared(), CleanupTempFiles(), logical_end_heap_rewrite(), mdclose(), mdimmedsync(), mdsyncfiletag(), mdtruncate(), ReorderBufferIterTXNFinish(), ReorderBufferRestoreChanges(), and ResourceOwnerReleaseInternal().

{
    Vfd        *vfdP;

    Assert(FileIsValid(file));

    DO_DB(elog(LOG, "FileClose: %d (%s)",
               file, VfdCache[file].fileName));

    vfdP = &VfdCache[file];

    if (!FileIsNotOpen(file))
    {
        /* close the file */
        if (close(vfdP->fd) != 0)
        {
            /*
             * We may need to panic on failure to close non-temporary files;
             * see LruDelete.
             */
            elog(vfdP->fdstate & FD_TEMP_FILE_LIMIT ? LOG : data_sync_elevel(LOG),
                 "could not close file \"%s\": %m", vfdP->fileName);
        }

        --nfile;
        vfdP->fd = VFD_CLOSED;

        /* remove the file from the lru ring */
        Delete(file);
    }

    if (vfdP->fdstate & FD_TEMP_FILE_LIMIT)
    {
        /* Subtract its size from current usage (do first in case of error) */
        temporary_files_size -= vfdP->fileSize;
        vfdP->fileSize = 0;
    }

    /*
     * Delete the file if it was temporary, and make a log entry if wanted
     */
    if (vfdP->fdstate & FD_DELETE_AT_CLOSE)
    {
        struct stat filestats;
        int         stat_errno;

        /*
         * If we get an error, as could happen within the ereport/elog calls,
         * we'll come right back here during transaction abort.  Reset the
         * flag to ensure that we can't get into an infinite loop.  This code
         * is arranged to ensure that the worst-case consequence is failing to
         * emit log message(s), not failing to attempt the unlink.
         */
        vfdP->fdstate &= ~FD_DELETE_AT_CLOSE;


        /* first try the stat() */
        if (stat(vfdP->fileName, &filestats))
            stat_errno = errno;
        else
            stat_errno = 0;

        /* in any case do the unlink */
        if (unlink(vfdP->fileName))
            ereport(LOG,
                    (errcode_for_file_access(),
                     errmsg("could not delete file \"%s\": %m", vfdP->fileName)));

        /* and last report the stat results */
        if (stat_errno == 0)
            ReportTemporaryFileUsage(vfdP->fileName, filestats.st_size);
        else
        {
            errno = stat_errno;
            ereport(LOG,
                    (errcode_for_file_access(),
                     errmsg("could not stat file \"%s\": %m", vfdP->fileName)));
        }
    }

    /* Unregister it from the resource owner */
    if (vfdP->resowner)
        ResourceOwnerForgetFile(vfdP->resowner, file);

    /*
     * Return the Vfd slot to the free list
     */
    FreeVfd(file);
}

FileGetRawDesc()

int FileGetRawDesc

(

File

file

)

Definition at line 2248 of file fd.c.

References Assert, vfd::fd, and FileIsValid.

{
    Assert(FileIsValid(file));
    return VfdCache[file].fd;
}

FileGetRawFlags()

int FileGetRawFlags

(

File

file

)

Definition at line 2258 of file fd.c.

References Assert, vfd::fileFlags, and FileIsValid.

{
    Assert(FileIsValid(file));
    return VfdCache[file].fileFlags;
}

FileGetRawMode()

mode_t FileGetRawMode

(

File

file

)

Definition at line 2268 of file fd.c.

References Assert, FileIsValid, and vfd::fileMode.

{
    Assert(FileIsValid(file));
    return VfdCache[file].fileMode;
}

FilePathName()

char* FilePathName

(

File

file

)

Definition at line 2232 of file fd.c.

References Assert, FileIsValid, and vfd::fileName.

Referenced by _mdnblocks(), BufFileDumpBuffer(), BufFileLoadBuffer(), BufFileSeek(), BufFileSize(), BufFileTruncateShared(), mdextend(), mdimmedsync(), mdread(), mdsyncfiletag(), mdtruncate(), mdwrite(), and register_dirty_segment().

{
    Assert(FileIsValid(file));

    return VfdCache[file].fileName;
}

FilePrefetch()

int FilePrefetch	(	File	file,
		off_t	offset,
		int	amount,
		uint32	wait_event_info
	)

Definition at line 1954 of file fd.c.

References Assert, DO_DB, elog, vfd::fd, FileAccess(), FileIsValid, vfd::fileName, INT64_FORMAT, LOG, pgstat_report_wait_end(), and pgstat_report_wait_start().

Referenced by mdprefetch().

{
#if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_WILLNEED)
    int         returnCode;

    Assert(FileIsValid(file));

    DO_DB(elog(LOG, "FilePrefetch: %d (%s) " INT64_FORMAT " %d",
               file, VfdCache[file].fileName,
               (int64) offset, amount));

    returnCode = FileAccess(file);
    if (returnCode < 0)
        return returnCode;

    pgstat_report_wait_start(wait_event_info);
    returnCode = posix_fadvise(VfdCache[file].fd, offset, amount,
                               POSIX_FADV_WILLNEED);
    pgstat_report_wait_end();

    return returnCode;
#else
    Assert(FileIsValid(file));
    return 0;
#endif
}

FileRead()

int FileRead	(	File	file,
		char *	buffer,
		int	amount,
		off_t	offset,
		uint32	wait_event_info
	)

Definition at line 2005 of file fd.c.

References _dosmaperr(), Assert, DO_DB, EINTR, elog, error(), vfd::fd, FileAccess(), FileIsValid, vfd::fileName, INT64_FORMAT, LOG, pg_pread(), pg_usleep(), pgstat_report_wait_end(), and pgstat_report_wait_start().

Referenced by BufFileLoadBuffer(), mdread(), and ReorderBufferRestoreChanges().

{
    int         returnCode;
    Vfd        *vfdP;

    Assert(FileIsValid(file));

    DO_DB(elog(LOG, "FileRead: %d (%s) " INT64_FORMAT " %d %p",
               file, VfdCache[file].fileName,
               (int64) offset,
               amount, buffer));

    returnCode = FileAccess(file);
    if (returnCode < 0)
        return returnCode;

    vfdP = &VfdCache[file];

retry:
    pgstat_report_wait_start(wait_event_info);
    returnCode = pg_pread(vfdP->fd, buffer, amount, offset);
    pgstat_report_wait_end();

    if (returnCode < 0)
    {
        /*
         * Windows may run out of kernel buffers and return "Insufficient
         * system resources" error.  Wait a bit and retry to solve it.
         *
         * It is rumored that EINTR is also possible on some Unix filesystems,
         * in which case immediate retry is indicated.
         */
#ifdef WIN32
        DWORD       error = GetLastError();

        switch (error)
        {
            case ERROR_NO_SYSTEM_RESOURCES:
                pg_usleep(1000L);
                errno = EINTR;
                break;
            default:
                _dosmaperr(error);
                break;
        }
#endif
        /* OK to retry if interrupted */
        if (errno == EINTR)
            goto retry;
    }

    return returnCode;
}

FileSize()

off_t FileSize

(

File

file

)

Definition at line 2180 of file fd.c.

References Assert, DO_DB, elog, vfd::fd, FileAccess(), FileIsNotOpen, FileIsValid, vfd::fileName, and LOG.

Referenced by _mdnblocks(), BufFileSeek(), and BufFileSize().

{
    Assert(FileIsValid(file));

    DO_DB(elog(LOG, "FileSize %d (%s)",
               file, VfdCache[file].fileName));

    if (FileIsNotOpen(file))
    {
        if (FileAccess(file) < 0)
            return (off_t) -1;
    }

    return lseek(VfdCache[file].fd, 0, SEEK_END);
}

FileSync()

int FileSync	(	File	file,
		uint32	wait_event_info
	)

Definition at line 2159 of file fd.c.

References Assert, DO_DB, elog, vfd::fd, FileAccess(), FileIsValid, vfd::fileName, LOG, pg_fsync(), pgstat_report_wait_end(), and pgstat_report_wait_start().

Referenced by logical_end_heap_rewrite(), mdimmedsync(), mdsyncfiletag(), and register_dirty_segment().

{
    int         returnCode;

    Assert(FileIsValid(file));

    DO_DB(elog(LOG, "FileSync: %d (%s)",
               file, VfdCache[file].fileName));

    returnCode = FileAccess(file);
    if (returnCode < 0)
        return returnCode;

    pgstat_report_wait_start(wait_event_info);
    returnCode = pg_fsync(VfdCache[file].fd);
    pgstat_report_wait_end();

    return returnCode;
}

FileTruncate()

int FileTruncate	(	File	file,
		off_t	offset,
		uint32	wait_event_info
	)

Definition at line 2197 of file fd.c.

References Assert, DO_DB, elog, vfd::fd, FD_TEMP_FILE_LIMIT, vfd::fdstate, FileAccess(), FileIsValid, vfd::fileName, vfd::fileSize, ftruncate, LOG, pgstat_report_wait_end(), pgstat_report_wait_start(), and temporary_files_size.

Referenced by BufFileTruncateShared(), and mdtruncate().

{
    int         returnCode;

    Assert(FileIsValid(file));

    DO_DB(elog(LOG, "FileTruncate %d (%s)",
               file, VfdCache[file].fileName));

    returnCode = FileAccess(file);
    if (returnCode < 0)
        return returnCode;

    pgstat_report_wait_start(wait_event_info);
    returnCode = ftruncate(VfdCache[file].fd, offset);
    pgstat_report_wait_end();

    if (returnCode == 0 && VfdCache[file].fileSize > offset)
    {
        /* adjust our state for truncation of a temp file */
        Assert(VfdCache[file].fdstate & FD_TEMP_FILE_LIMIT);
        temporary_files_size -= VfdCache[file].fileSize - offset;
        VfdCache[file].fileSize = offset;
    }

    return returnCode;
}

FileWrite()

int FileWrite	(	File	file,
		char *	buffer,
		int	amount,
		off_t	offset,
		uint32	wait_event_info
	)

Definition at line 2061 of file fd.c.

References _dosmaperr(), Assert, DO_DB, EINTR, elog, ereport, errcode(), errmsg(), ERROR, error(), vfd::fd, FD_TEMP_FILE_LIMIT, vfd::fdstate, FileAccess(), FileIsValid, vfd::fileName, vfd::fileSize, INT64_FORMAT, LOG, pg_pwrite(), pg_usleep(), pgstat_report_wait_end(), pgstat_report_wait_start(), temp_file_limit, and temporary_files_size.

Referenced by BufFileDumpBuffer(), logical_heap_rewrite_flush_mappings(), mdextend(), and mdwrite().

{
    int         returnCode;
    Vfd        *vfdP;

    Assert(FileIsValid(file));

    DO_DB(elog(LOG, "FileWrite: %d (%s) " INT64_FORMAT " %d %p",
               file, VfdCache[file].fileName,
               (int64) offset,
               amount, buffer));

    returnCode = FileAccess(file);
    if (returnCode < 0)
        return returnCode;

    vfdP = &VfdCache[file];

    /*
     * If enforcing temp_file_limit and it's a temp file, check to see if the
     * write would overrun temp_file_limit, and throw error if so.  Note: it's
     * really a modularity violation to throw error here; we should set errno
     * and return -1.  However, there's no way to report a suitable error
     * message if we do that.  All current callers would just throw error
     * immediately anyway, so this is safe at present.
     */
    if (temp_file_limit >= 0 && (vfdP->fdstate & FD_TEMP_FILE_LIMIT))
    {
        off_t       past_write = offset + amount;

        if (past_write > vfdP->fileSize)
        {
            uint64      newTotal = temporary_files_size;

            newTotal += past_write - vfdP->fileSize;
            if (newTotal > (uint64) temp_file_limit * (uint64) 1024)
                ereport(ERROR,
                        (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
                         errmsg("temporary file size exceeds temp_file_limit (%dkB)",
                                temp_file_limit)));
        }
    }

retry:
    errno = 0;
    pgstat_report_wait_start(wait_event_info);
    returnCode = pg_pwrite(VfdCache[file].fd, buffer, amount, offset);
    pgstat_report_wait_end();

    /* if write didn't set errno, assume problem is no disk space */
    if (returnCode != amount && errno == 0)
        errno = ENOSPC;

    if (returnCode >= 0)
    {
        /*
         * Maintain fileSize and temporary_files_size if it's a temp file.
         */
        if (vfdP->fdstate & FD_TEMP_FILE_LIMIT)
        {
            off_t       past_write = offset + amount;

            if (past_write > vfdP->fileSize)
            {
                temporary_files_size += past_write - vfdP->fileSize;
                vfdP->fileSize = past_write;
            }
        }
    }
    else
    {
        /*
         * See comments in FileRead()
         */
#ifdef WIN32
        DWORD       error = GetLastError();

        switch (error)
        {
            case ERROR_NO_SYSTEM_RESOURCES:
                pg_usleep(1000L);
                errno = EINTR;
                break;
            default:
                _dosmaperr(error);
                break;
        }
#endif
        /* OK to retry if interrupted */
        if (errno == EINTR)
            goto retry;
    }

    return returnCode;
}

FileWriteback()

void FileWriteback	(	File	file,
		off_t	offset,
		off_t	nbytes,
		uint32	wait_event_info
	)

Definition at line 1982 of file fd.c.

References Assert, DO_DB, elog, vfd::fd, FileAccess(), FileIsValid, vfd::fileName, INT64_FORMAT, LOG, pg_flush_data(), pgstat_report_wait_end(), and pgstat_report_wait_start().

Referenced by mdwriteback().

{
    int         returnCode;

    Assert(FileIsValid(file));

    DO_DB(elog(LOG, "FileWriteback: %d (%s) " INT64_FORMAT " " INT64_FORMAT,
               file, VfdCache[file].fileName,
               (int64) offset, (int64) nbytes));

    if (nbytes <= 0)
        return;

    returnCode = FileAccess(file);
    if (returnCode < 0)
        return;

    pgstat_report_wait_start(wait_event_info);
    pg_flush_data(VfdCache[file].fd, offset, nbytes);
    pgstat_report_wait_end();
}

FreeDir()

int FreeDir

(

DIR *

dir

)

Definition at line 2733 of file fd.c.

References AllocateDescDir, closedir(), AllocateDesc::desc, AllocateDesc::dir, DO_DB, elog, FreeDesc(), i, AllocateDesc::kind, LOG, numAllocatedDescs, and WARNING.

Referenced by calculate_database_size(), calculate_tablespace_size(), CheckPointLogicalRewriteHeap(), CheckPointSnapBuild(), CleanupBackupHistory(), copydir(), db_dir_size(), DeleteAllExportedSnapshotFiles(), destroy_tablespace_directories(), directory_is_empty(), do_pg_start_backup(), dsm_cleanup_for_mmap(), extension_file_exists(), get_ext_ver_list(), getInstallationPaths(), movedb(), ParseTzFile(), perform_base_backup(), pg_available_extension_versions(), pg_available_extensions(), pg_logdir_ls_internal(), pg_ls_dir(), pg_ls_dir_files(), pg_tablespace_databases(), pg_tzenumerate_end(), pg_tzenumerate_next(), pgarch_readyXlog(), pgstat_reset_remove_files(), RelationCacheInitFileRemove(), RelationCacheInitFileRemoveInDir(), RemoveNonParentXlogFiles(), RemoveOldXlogFiles(), RemovePgTempFiles(), RemovePgTempFilesInDir(), RemovePgTempRelationFiles(), RemovePgTempRelationFilesInDbspace(), RemoveTempXlogFiles(), ReorderBufferCleanupSerializedTXNs(), ResetUnloggedRelations(), ResetUnloggedRelationsInDbspaceDir(), ResetUnloggedRelationsInTablespaceDir(), restoreTwoPhaseData(), scan_directory_ci(), sendDir(), SlruScanDirectory(), StartupReorderBuffer(), StartupReplicationSlots(), UpdateLogicalMappings(), and walkdir().

{
    int         i;

    /* Nothing to do if AllocateDir failed */
    if (dir == NULL)
        return 0;

    DO_DB(elog(LOG, "FreeDir: Allocated %d", numAllocatedDescs));

    /* Remove dir from list of allocated dirs, if it's present */
    for (i = numAllocatedDescs; --i >= 0;)
    {
        AllocateDesc *desc = &allocatedDescs[i];

        if (desc->kind == AllocateDescDir && desc->desc.dir == dir)
            return FreeDesc(desc);
    }

    /* Only get here if someone passes us a dir not in allocatedDescs */
    elog(WARNING, "dir passed to FreeDir was not obtained from AllocateDir");

    return closedir(dir);
}

FreeFile()

int FreeFile

(

FILE *

file

)

Definition at line 2553 of file fd.c.

References AllocateDescFile, AllocateDesc::desc, DO_DB, elog, AllocateDesc::file, FreeDesc(), i, AllocateDesc::kind, LOG, numAllocatedDescs, and WARNING.

Referenced by _ShowOption(), AlterSystemSetConfigFile(), apw_dump_now(), apw_load_buffers(), BackendRun(), checkControlFile(), do_pg_start_backup(), do_pg_stop_backup(), EndCopy(), EndCopyFrom(), entry_reset(), existsTimeLineHistory(), ExportSnapshot(), fill_hba_view(), gc_qtexts(), ImportSnapshot(), load_dh_file(), load_hba(), load_ident(), load_relcache_init_file(), parse_extension_control_file(), ParseTzFile(), pg_backup_start_time(), pg_current_logfile(), pg_file_write_internal(), pg_promote(), PGSharedMemoryAttach(), pgss_shmem_shutdown(), pgss_shmem_startup(), pgstat_read_db_statsfile(), pgstat_read_db_statsfile_timestamp(), pgstat_read_statsfiles(), pgstat_write_db_statsfile(), pgstat_write_statsfiles(), PostmasterMarkPIDForWorkerNotify(), read_backup_label(), read_binary_file(), read_tablespace_map(), read_whole_file(), readTimeLineHistory(), tokenize_inc_file(), tsearch_readline_end(), ValidatePgVersion(), write_relcache_init_file(), XLogArchiveForceDone(), and XLogArchiveNotify().

{
    int         i;

    DO_DB(elog(LOG, "FreeFile: Allocated %d", numAllocatedDescs));

    /* Remove file from list of allocated files, if it's present */
    for (i = numAllocatedDescs; --i >= 0;)
    {
        AllocateDesc *desc = &allocatedDescs[i];

        if (desc->kind == AllocateDescFile && desc->desc.file == file)
            return FreeDesc(desc);
    }

    /* Only get here if someone passes us a file not in allocatedDescs */
    elog(WARNING, "file passed to FreeFile was not obtained from AllocateFile");

    return fclose(file);
}

fsync_fname()

void fsync_fname	(	const char *	fname,
		bool	isdir
	)

Definition at line 661 of file fd.c.

References data_sync_elevel(), ERROR, and fsync_fname_ext().

Referenced by _CloseArchive(), CheckPointTwoPhase(), copydir(), CreateSlotOnDisk(), dir_close(), dir_finish(), dir_open_for_write(), main(), ReplicationSlotDropPtr(), ResetUnloggedRelationsInDbspaceDir(), RestoreSlotFromDisk(), SaveSlotToPath(), SimpleLruWriteAll(), SnapBuildRestore(), SnapBuildSerialize(), StartupReplicationSlots(), and tar_finish().

{
    fsync_fname_ext(fname, isdir, false, data_sync_elevel(ERROR));
}

fsync_fname_ext()

int fsync_fname_ext	(	const char *	fname,
		bool	isdir,
		bool	ignore_perm,
		int	elevel
	)

Definition at line 3496 of file fd.c.

References CloseTransientFile(), ereport, errcode_for_file_access(), errmsg(), vfd::fd, OpenTransientFile(), PG_BINARY, and pg_fsync().

Referenced by datadir_fsync_fname(), durable_rename(), durable_rename_excl(), fsync_fname(), fsync_parent_path(), and pg_file_sync().

{
    int         fd;
    int         flags;
    int         returncode;

    /*
     * Some OSs require directories to be opened read-only whereas other
     * systems don't allow us to fsync files opened read-only; so we need both
     * cases here.  Using O_RDWR will cause us to fail to fsync files that are
     * not writable by our userid, but we assume that's OK.
     */
    flags = PG_BINARY;
    if (!isdir)
        flags |= O_RDWR;
    else
        flags |= O_RDONLY;

    fd = OpenTransientFile(fname, flags);

    /*
     * Some OSs don't allow us to open directories at all (Windows returns
     * EACCES), just ignore the error in that case.  If desired also silently
     * ignoring errors about unreadable files. Log others.
     */
    if (fd < 0 && isdir && (errno == EISDIR || errno == EACCES))
        return 0;
    else if (fd < 0 && ignore_perm && errno == EACCES)
        return 0;
    else if (fd < 0)
    {
        ereport(elevel,
                (errcode_for_file_access(),
                 errmsg("could not open file \"%s\": %m", fname)));
        return -1;
    }

    returncode = pg_fsync(fd);

    /*
     * Some OSes don't allow us to fsync directories at all, so we can ignore
     * those errors. Anything else needs to be logged.
     */
    if (returncode != 0 && !(isdir && (errno == EBADF || errno == EINVAL)))
    {
        int         save_errno;

        /* close file upon error, might not be in transaction context */
        save_errno = errno;
        (void) CloseTransientFile(fd);
        errno = save_errno;

        ereport(elevel,
                (errcode_for_file_access(),
                 errmsg("could not fsync file \"%s\": %m", fname)));
        return -1;
    }

    if (CloseTransientFile(fd) != 0)
    {
        ereport(elevel,
                (errcode_for_file_access(),
                 errmsg("could not close file \"%s\": %m", fname)));
        return -1;
    }

    return 0;
}

GetNextTempTableSpace()

Oid GetNextTempTableSpace

(

void

)

Definition at line 2882 of file fd.c.

References InvalidOid, nextTempTableSpace, numTempTableSpaces, and tempTableSpaces.

Referenced by GetDefaultTablespace(), and OpenTemporaryFile().

{
    if (numTempTableSpaces > 0)
    {
        /* Advance nextTempTableSpace counter with wraparound */
        if (++nextTempTableSpace >= numTempTableSpaces)
            nextTempTableSpace = 0;
        return tempTableSpaces[nextTempTableSpace];
    }
    return InvalidOid;
}

GetTempTablespaces()

int GetTempTablespaces	(	Oid *	tableSpaces,
		int	numSpaces
	)

Definition at line 2864 of file fd.c.

References Assert, i, numTempTableSpaces, tempTableSpaces, and TempTablespacesAreSet().

Referenced by SharedFileSetInit().

{
    int         i;

    Assert(TempTablespacesAreSet());
    for (i = 0; i < numTempTableSpaces && i < numSpaces; ++i)
        tableSpaces[i] = tempTableSpaces[i];

    return i;
}

InitFileAccess()

void InitFileAccess

(

void

)

Definition at line 854 of file fd.c.

References Assert, AtProcExit_Files(), ereport, errcode(), errmsg(), FATAL, vfd::fd, malloc, MemSet, on_proc_exit(), SizeVfdCache, and VFD_CLOSED.

Referenced by BaseInit().

{
    Assert(SizeVfdCache == 0);  /* call me only once */

    /* initialize cache header entry */
    VfdCache = (Vfd *) malloc(sizeof(Vfd));
    if (VfdCache == NULL)
        ereport(FATAL,
                (errcode(ERRCODE_OUT_OF_MEMORY),
                 errmsg("out of memory")));

    MemSet((char *) &(VfdCache[0]), 0, sizeof(Vfd));
    VfdCache->fd = VFD_CLOSED;

    SizeVfdCache = 1;

    /* register proc-exit hook to ensure temp files are dropped at exit */
    on_proc_exit(AtProcExit_Files, 0);
}

looks_like_temp_rel_name()

bool looks_like_temp_rel_name

(

const char *

name

)

Definition at line 3219 of file fd.c.

References forkname_chars().

Referenced by RemovePgTempRelationFilesInDbspace(), and sendDir().

{
    int         pos;
    int         savepos;

    /* Must start with "t". */
    if (name[0] != 't')
        return false;

    /* Followed by a non-empty string of digits and then an underscore. */
    for (pos = 1; isdigit((unsigned char) name[pos]); ++pos)
        ;
    if (pos == 1 || name[pos] != '_')
        return false;

    /* Followed by another nonempty string of digits. */
    for (savepos = ++pos; isdigit((unsigned char) name[pos]); ++pos)
        ;
    if (savepos == pos)
        return false;

    /* We might have _forkname or .segment or both. */
    if (name[pos] == '_')
    {
        int         forkchar = forkname_chars(&name[pos + 1], NULL);

        if (forkchar <= 0)
            return false;
        pos += forkchar + 1;
    }
    if (name[pos] == '.')
    {
        int         segchar;

        for (segchar = 1; isdigit((unsigned char) name[pos + segchar]); ++segchar)
            ;
        if (segchar <= 1)
            return false;
        pos += segchar;
    }

    /* Now we should be at the end. */
    if (name[pos] != '\0')
        return false;
    return true;
}

MakePGDirectory()

int MakePGDirectory

(

const char *

directoryName

)

Definition at line 3612 of file fd.c.

References mkdir, and pg_dir_create_mode.

Referenced by BackendRun(), copydir(), create_tablespace_directories(), CreateSlotOnDisk(), OpenTemporaryFileInTablespace(), PathNameCreateTemporaryDir(), SysLogger_Start(), SysLoggerMain(), TablespaceCreateDbspace(), and ValidateXLOGDirectoryStructure().

{
    return mkdir(directoryName, pg_dir_create_mode);
}

OpenPipeStream()

FILE* OpenPipeStream	(	const char *	command,
		const char *	mode
	)

Definition at line 2457 of file fd.c.

References AllocateDescPipe, AllocateDesc::create_subid, AllocateDesc::desc, DO_DB, elog, ereport, errcode(), errmsg(), ERROR, AllocateDesc::file, GetCurrentSubTransactionId(), AllocateDesc::kind, LOG, maxAllocatedDescs, numAllocatedDescs, pqsignal(), ReleaseLruFile(), ReleaseLruFiles(), reserveAllocatedDesc(), SIG_DFL, SIG_IGN, SIGPIPE, and generate_unaccent_rules::stdout.

Referenced by BeginCopyFrom(), BeginCopyTo(), pg_import_system_collations(), and run_ssl_passphrase_command().

{
    FILE       *file;
    int         save_errno;

    DO_DB(elog(LOG, "OpenPipeStream: Allocated %d (%s)",
               numAllocatedDescs, command));

    /* Can we allocate another non-virtual FD? */
    if (!reserveAllocatedDesc())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
                 errmsg("exceeded maxAllocatedDescs (%d) while trying to execute command \"%s\"",
                        maxAllocatedDescs, command)));

    /* Close excess kernel FDs. */
    ReleaseLruFiles();

TryAgain:
    fflush(stdout);
    fflush(stderr);
    pqsignal(SIGPIPE, SIG_DFL);
    errno = 0;
    file = popen(command, mode);
    save_errno = errno;
    pqsignal(SIGPIPE, SIG_IGN);
    errno = save_errno;
    if (file != NULL)
    {
        AllocateDesc *desc = &allocatedDescs[numAllocatedDescs];

        desc->kind = AllocateDescPipe;
        desc->desc.file = file;
        desc->create_subid = GetCurrentSubTransactionId();
        numAllocatedDescs++;
        return desc->desc.file;
    }

    if (errno == EMFILE || errno == ENFILE)
    {
        ereport(LOG,
                (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
                 errmsg("out of file descriptors: %m; release and retry")));
        if (ReleaseLruFile())
            goto TryAgain;
        errno = save_errno;
    }

    return NULL;
}

OpenTemporaryFile()

File OpenTemporaryFile

(

bool

interXact

)

Definition at line 1606 of file fd.c.

References CurrentResourceOwner, FD_DELETE_AT_CLOSE, FD_TEMP_FILE_LIMIT, vfd::fdstate, GetNextTempTableSpace(), MyDatabaseTableSpace, numTempTableSpaces, OidIsValid, OpenTemporaryFileInTablespace(), RegisterTemporaryFile(), and ResourceOwnerEnlargeFiles().

Referenced by BufFileCreateTemp(), and extendBufFile().

{
    File        file = 0;

    /*
     * Make sure the current resource owner has space for this File before we
     * open it, if we'll be registering it below.
     */
    if (!interXact)
        ResourceOwnerEnlargeFiles(CurrentResourceOwner);

    /*
     * If some temp tablespace(s) have been given to us, try to use the next
     * one.  If a given tablespace can't be found, we silently fall back to
     * the database's default tablespace.
     *
     * BUT: if the temp file is slated to outlive the current transaction,
     * force it into the database's default tablespace, so that it will not
     * pose a threat to possible tablespace drop attempts.
     */
    if (numTempTableSpaces > 0 && !interXact)
    {
        Oid         tblspcOid = GetNextTempTableSpace();

        if (OidIsValid(tblspcOid))
            file = OpenTemporaryFileInTablespace(tblspcOid, false);
    }

    /*
     * If not, or if tablespace is bad, create in database's default
     * tablespace.  MyDatabaseTableSpace should normally be set before we get
     * here, but just in case it isn't, fall back to pg_default tablespace.
     */
    if (file <= 0)
        file = OpenTemporaryFileInTablespace(MyDatabaseTableSpace ?
                                             MyDatabaseTableSpace :
                                             DEFAULTTABLESPACE_OID,
                                             true);

    /* Mark it for deletion at close and temporary file size limit */
    VfdCache[file].fdstate |= FD_DELETE_AT_CLOSE | FD_TEMP_FILE_LIMIT;

    /* Register it with the current resource owner */
    if (!interXact)
        RegisterTemporaryFile(file);

    return file;
}

OpenTransientFile()

int OpenTransientFile	(	const char *	fileName,
		int	fileFlags
	)

Definition at line 2404 of file fd.c.

References OpenTransientFilePerm(), and pg_file_create_mode.

Referenced by ApplyLogicalMappingFile(), CheckPointLogicalRewriteHeap(), CheckPointReplicationOrigin(), copy_file(), dsm_impl_mmap(), durable_rename(), fsync_fname_ext(), get_controlfile(), heap_xlog_logical_rewrite(), lo_import_internal(), load_relmap_file(), perform_base_backup(), pg_truncate(), qtext_load_file(), qtext_store(), ReadTwoPhaseFile(), RecreateTwoPhaseFile(), ReorderBufferSerializeTXN(), RestoreSlotFromDisk(), SaveSlotToPath(), sendFile(), SendTimeLineHistory(), SimpleLruDoesPhysicalPageExist(), SlruPhysicalReadPage(), SlruPhysicalWritePage(), SlruSyncFileTag(), SnapBuildRestore(), SnapBuildSerialize(), StartupReplicationOrigin(), walkdir(), write_relmap_file(), writeTimeLineHistory(), writeTimeLineHistoryFile(), and XLogFileCopy().

{
    return OpenTransientFilePerm(fileName, fileFlags, pg_file_create_mode);
}

OpenTransientFilePerm()

int OpenTransientFilePerm	(	const char *	fileName,
		int	fileFlags,
		mode_t	fileMode
	)

Definition at line 2413 of file fd.c.

References AllocateDescRawFD, BasicOpenFilePerm(), AllocateDesc::create_subid, AllocateDesc::desc, DO_DB, elog, ereport, errcode(), errmsg(), ERROR, vfd::fd, AllocateDesc::fd, GetCurrentSubTransactionId(), AllocateDesc::kind, LOG, maxAllocatedDescs, numAllocatedDescs, ReleaseLruFiles(), and reserveAllocatedDesc().

Referenced by be_lo_export(), and OpenTransientFile().

{
    int         fd;

    DO_DB(elog(LOG, "OpenTransientFile: Allocated %d (%s)",
               numAllocatedDescs, fileName));

    /* Can we allocate another non-virtual FD? */
    if (!reserveAllocatedDesc())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
                 errmsg("exceeded maxAllocatedDescs (%d) while trying to open file \"%s\"",
                        maxAllocatedDescs, fileName)));

    /* Close excess kernel FDs. */
    ReleaseLruFiles();

    fd = BasicOpenFilePerm(fileName, fileFlags, fileMode);

    if (fd >= 0)
    {
        AllocateDesc *desc = &allocatedDescs[numAllocatedDescs];

        desc->kind = AllocateDescRawFD;
        desc->desc.fd = fd;
        desc->create_subid = GetCurrentSubTransactionId();
        numAllocatedDescs++;

        return fd;
    }

    return -1;                  /* failure */
}

PathNameCreateTemporaryDir()

void PathNameCreateTemporaryDir	(	const char *	base,
		const char *	name
	)

Definition at line 1542 of file fd.c.

References ereport, errcode_for_file_access(), errmsg(), ERROR, and MakePGDirectory().

Referenced by SharedFileSetCreate().

{
    if (MakePGDirectory(directory) < 0)
    {
        if (errno == EEXIST)
            return;

        /*
         * Failed.  Try to create basedir first in case it's missing. Tolerate
         * EEXIST to close a race against another process following the same
         * algorithm.
         */
        if (MakePGDirectory(basedir) < 0 && errno != EEXIST)
            ereport(ERROR,
                    (errcode_for_file_access(),
                     errmsg("cannot create temporary directory \"%s\": %m",
                            basedir)));

        /* Try again. */
        if (MakePGDirectory(directory) < 0 && errno != EEXIST)
            ereport(ERROR,
                    (errcode_for_file_access(),
                     errmsg("cannot create temporary subdirectory \"%s\": %m",
                            directory)));
    }
}

PathNameCreateTemporaryFile()

File PathNameCreateTemporaryFile	(	const char *	name,
		bool	error_on_failure
	)

Definition at line 1741 of file fd.c.

References CurrentResourceOwner, ereport, errcode_for_file_access(), errmsg(), ERROR, FD_TEMP_FILE_LIMIT, vfd::fdstate, PathNameOpenFile(), PG_BINARY, RegisterTemporaryFile(), and ResourceOwnerEnlargeFiles().

Referenced by SharedFileSetCreate().

{
    File        file;

    ResourceOwnerEnlargeFiles(CurrentResourceOwner);

    /*
     * Open the file.  Note: we don't use O_EXCL, in case there is an orphaned
     * temp file that can be reused.
     */
    file = PathNameOpenFile(path, O_RDWR | O_CREAT | O_TRUNC | PG_BINARY);
    if (file <= 0)
    {
        if (error_on_failure)
            ereport(ERROR,
                    (errcode_for_file_access(),
                     errmsg("could not create temporary file \"%s\": %m",
                            path)));
        else
            return file;
    }

    /* Mark it for temp_file_limit accounting. */
    VfdCache[file].fdstate |= FD_TEMP_FILE_LIMIT;

    /* Register it for automatic close. */
    RegisterTemporaryFile(file);

    return file;
}

PathNameDeleteTemporaryDir()

void PathNameDeleteTemporaryDir

(

const char *

name

)

Definition at line 1573 of file fd.c.

References LOG, stat, unlink_if_exists_fname(), and walkdir().

Referenced by SharedFileSetDeleteAll().

{
    struct stat statbuf;

    /* Silently ignore missing directory. */
    if (stat(dirname, &statbuf) != 0 && errno == ENOENT)
        return;

    /*
     * Currently, walkdir doesn't offer a way for our passed in function to
     * maintain state.  Perhaps it should, so that we could tell the caller
     * whether this operation succeeded or failed.  Since this operation is
     * used in a cleanup path, we wouldn't actually behave differently: we'll
     * just log failures.
     */
    walkdir(dirname, unlink_if_exists_fname, false, LOG);
}

PathNameDeleteTemporaryFile()

bool PathNameDeleteTemporaryFile	(	const char *	name,
		bool	error_on_failure
	)

Definition at line 1808 of file fd.c.

References ereport, errcode_for_file_access(), errmsg(), ERROR, LOG, ReportTemporaryFileUsage(), stat::st_size, and stat.

Referenced by SharedFileSetDelete(), and unlink_if_exists_fname().

{
    struct stat filestats;
    int         stat_errno;

    /* Get the final size for pgstat reporting. */
    if (stat(path, &filestats) != 0)
        stat_errno = errno;
    else
        stat_errno = 0;

    /*
     * Unlike FileClose's automatic file deletion code, we tolerate
     * non-existence to support BufFileDeleteShared which doesn't know how
     * many segments it has to delete until it runs out.
     */
    if (stat_errno == ENOENT)
        return false;

    if (unlink(path) < 0)
    {
        if (errno != ENOENT)
            ereport(error_on_failure ? ERROR : LOG,
                    (errcode_for_file_access(),
                     errmsg("could not unlink temporary file \"%s\": %m",
                            path)));
        return false;
    }

    if (stat_errno == 0)
        ReportTemporaryFileUsage(path, filestats.st_size);
    else
    {
        errno = stat_errno;
        ereport(LOG,
                (errcode_for_file_access(),
                 errmsg("could not stat file \"%s\": %m", path)));
    }

    return true;
}

PathNameOpenFile()

File PathNameOpenFile	(	const char *	fileName,
		int	fileFlags
	)

Definition at line 1465 of file fd.c.

References PathNameOpenFilePerm(), and pg_file_create_mode.

Referenced by _mdfd_openseg(), logical_rewrite_log_mapping(), mdcreate(), mdopenfork(), mdsyncfiletag(), OpenTemporaryFileInTablespace(), PathNameCreateTemporaryFile(), PathNameOpenTemporaryFile(), and ReorderBufferRestoreChanges().

{
    return PathNameOpenFilePerm(fileName, fileFlags, pg_file_create_mode);
}

PathNameOpenFilePerm()

File PathNameOpenFilePerm	(	const char *	fileName,
		int	fileFlags,
		mode_t	fileMode
	)

Definition at line 1478 of file fd.c.

References AllocateVfd(), BasicOpenFilePerm(), DO_DB, elog, ereport, errcode(), errmsg(), ERROR, vfd::fd, vfd::fdstate, vfd::fileFlags, vfd::fileMode, vfd::fileName, vfd::fileSize, free, FreeVfd(), Insert(), LOG, nfile, ReleaseLruFiles(), and vfd::resowner.

Referenced by PathNameOpenFile().

{
    char       *fnamecopy;
    File        file;
    Vfd        *vfdP;

    DO_DB(elog(LOG, "PathNameOpenFilePerm: %s %x %o",
               fileName, fileFlags, fileMode));

    /*
     * We need a malloc'd copy of the file name; fail cleanly if no room.
     */
    fnamecopy = strdup(fileName);
    if (fnamecopy == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_OUT_OF_MEMORY),
                 errmsg("out of memory")));

    file = AllocateVfd();
    vfdP = &VfdCache[file];

    /* Close excess kernel FDs. */
    ReleaseLruFiles();

    vfdP->fd = BasicOpenFilePerm(fileName, fileFlags, fileMode);

    if (vfdP->fd < 0)
    {
        int         save_errno = errno;

        FreeVfd(file);
        free(fnamecopy);
        errno = save_errno;
        return -1;
    }
    ++nfile;
    DO_DB(elog(LOG, "PathNameOpenFile: success %d",
               vfdP->fd));

    vfdP->fileName = fnamecopy;
    /* Saved flags are adjusted to be OK for re-opening file */
    vfdP->fileFlags = fileFlags & ~(O_CREAT | O_TRUNC | O_EXCL);
    vfdP->fileMode = fileMode;
    vfdP->fileSize = 0;
    vfdP->fdstate = 0x0;
    vfdP->resowner = NULL;

    Insert(file);

    return file;
}

PathNameOpenTemporaryFile()

File PathNameOpenTemporaryFile	(	const char *	path,
		int	mode
	)

Definition at line 1779 of file fd.c.

References CurrentResourceOwner, ereport, errcode_for_file_access(), errmsg(), ERROR, PathNameOpenFile(), PG_BINARY, RegisterTemporaryFile(), and ResourceOwnerEnlargeFiles().

Referenced by SharedFileSetOpen().

{
    File        file;

    ResourceOwnerEnlargeFiles(CurrentResourceOwner);

    file = PathNameOpenFile(path, mode | PG_BINARY);

    /* If no such file, then we don't raise an error. */
    if (file <= 0 && errno != ENOENT)
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not open temporary file \"%s\": %m",
                        path)));

    if (file > 0)
    {
        /* Register it for automatic close. */
        RegisterTemporaryFile(file);
    }

    return file;
}

pg_fdatasync()

int pg_fdatasync

(

int

fd

)

Definition at line 437 of file fd.c.

References enableFsync, and fsync.

Referenced by issue_xlog_fsync().

{
    if (enableFsync)
    {
#ifdef HAVE_FDATASYNC
        return fdatasync(fd);
#else
        return fsync(fd);
#endif
    }
    else
        return 0;
}

pg_flush_data()

void pg_flush_data	(	int	fd,
		off_t	offset,
		off_t	amount
	)

Definition at line 457 of file fd.c.

References data_sync_elevel(), elevel, enableFsync, ereport, errcode_for_file_access(), errmsg(), FATAL, MAP_FAILED, and WARNING.

Referenced by copy_file(), FileWriteback(), and walkdir().

{
    /*
     * Right now file flushing is primarily used to avoid making later
     * fsync()/fdatasync() calls have less impact. Thus don't trigger flushes
     * if fsyncs are disabled - that's a decision we might want to make
     * configurable at some point.
     */
    if (!enableFsync)
        return;

    /*
     * We compile all alternatives that are supported on the current platform,
     * to find portability problems more easily.
     */
#if defined(HAVE_SYNC_FILE_RANGE)
    {
        int         rc;
        static bool not_implemented_by_kernel = false;

        if (not_implemented_by_kernel)
            return;

        /*
         * sync_file_range(SYNC_FILE_RANGE_WRITE), currently linux specific,
         * tells the OS that writeback for the specified blocks should be
         * started, but that we don't want to wait for completion.  Note that
         * this call might block if too much dirty data exists in the range.
         * This is the preferable method on OSs supporting it, as it works
         * reliably when available (contrast to msync()) and doesn't flush out
         * clean data (like FADV_DONTNEED).
         */
        rc = sync_file_range(fd, offset, nbytes,
                             SYNC_FILE_RANGE_WRITE);
        if (rc != 0)
        {
            int         elevel;

            /*
             * For systems that don't have an implementation of
             * sync_file_range() such as Windows WSL, generate only one
             * warning and then suppress all further attempts by this process.
             */
            if (errno == ENOSYS)
            {
                elevel = WARNING;
                not_implemented_by_kernel = true;
            }
            else
                elevel = data_sync_elevel(WARNING);

            ereport(elevel,
                    (errcode_for_file_access(),
                     errmsg("could not flush dirty data: %m")));
        }

        return;
    }
#endif
#if !defined(WIN32) && defined(MS_ASYNC)
    {
        void       *p;
        static int  pagesize = 0;

        /*
         * On several OSs msync(MS_ASYNC) on a mmap'ed file triggers
         * writeback. On linux it only does so if MS_SYNC is specified, but
         * then it does the writeback synchronously. Luckily all common linux
         * systems have sync_file_range().  This is preferable over
         * FADV_DONTNEED because it doesn't flush out clean data.
         *
         * We map the file (mmap()), tell the kernel to sync back the contents
         * (msync()), and then remove the mapping again (munmap()).
         */

        /* mmap() needs actual length if we want to map whole file */
        if (offset == 0 && nbytes == 0)
        {
            nbytes = lseek(fd, 0, SEEK_END);
            if (nbytes < 0)
            {
                ereport(WARNING,
                        (errcode_for_file_access(),
                         errmsg("could not determine dirty data size: %m")));
                return;
            }
        }

        /*
         * Some platforms reject partial-page mmap() attempts.  To deal with
         * that, just truncate the request to a page boundary.  If any extra
         * bytes don't get flushed, well, it's only a hint anyway.
         */

        /* fetch pagesize only once */
        if (pagesize == 0)
            pagesize = sysconf(_SC_PAGESIZE);

        /* align length to pagesize, dropping any fractional page */
        if (pagesize > 0)
            nbytes = (nbytes / pagesize) * pagesize;

        /* fractional-page request is a no-op */
        if (nbytes <= 0)
            return;

        /*
         * mmap could well fail, particularly on 32-bit platforms where there
         * may simply not be enough address space.  If so, silently fall
         * through to the next implementation.
         */
        if (nbytes <= (off_t) SSIZE_MAX)
            p = mmap(NULL, nbytes, PROT_READ, MAP_SHARED, fd, offset);
        else
            p = MAP_FAILED;

        if (p != MAP_FAILED)
        {
            int         rc;

            rc = msync(p, (size_t) nbytes, MS_ASYNC);
            if (rc != 0)
            {
                ereport(data_sync_elevel(WARNING),
                        (errcode_for_file_access(),
                         errmsg("could not flush dirty data: %m")));
                /* NB: need to fall through to munmap()! */
            }

            rc = munmap(p, (size_t) nbytes);
            if (rc != 0)
            {
                /* FATAL error because mapping would remain */
                ereport(FATAL,
                        (errcode_for_file_access(),
                         errmsg("could not munmap() while flushing data: %m")));
            }

            return;
        }
    }
#endif
#if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED)
    {
        int         rc;

        /*
         * Signal the kernel that the passed in range should not be cached
         * anymore. This has the, desired, side effect of writing out dirty
         * data, and the, undesired, side effect of likely discarding useful
         * clean cached blocks.  For the latter reason this is the least
         * preferable method.
         */

        rc = posix_fadvise(fd, offset, nbytes, POSIX_FADV_DONTNEED);

        if (rc != 0)
        {
            /* don't error out, this is just a performance optimization */
            ereport(WARNING,
                    (errcode_for_file_access(),
                     errmsg("could not flush dirty data: %m")));
        }

        return;
    }
#endif
}

pg_fsync()

int pg_fsync

(

int

fd

)

Definition at line 347 of file fd.c.

References Assert, fstat, pg_fsync_no_writethrough(), pg_fsync_writethrough(), S_ISDIR, stat::st_mode, sync_method, and SYNC_METHOD_FSYNC_WRITETHROUGH.

Referenced by AddToDataDirLockFile(), assign_xlog_sync_method(), BootStrapXLOG(), CheckPointLogicalRewriteHeap(), CreateLockFile(), do_pg_start_backup(), durable_rename(), FileSync(), fsync_fname_ext(), heap_xlog_logical_rewrite(), readRecoverySignalFile(), RecreateTwoPhaseFile(), RestoreSlotFromDisk(), SaveSlotToPath(), SlruPhysicalWritePage(), SlruSyncFileTag(), SnapBuildSerialize(), update_controlfile(), write_auto_conf_file(), write_relmap_file(), WriteControlFile(), writeTimeLineHistory(), writeTimeLineHistoryFile(), XLogFileCopy(), and XLogFileInit().

{
#if !defined(WIN32) && defined(USE_ASSERT_CHECKING)
    struct stat st;

    /*
     * Some operating system implementations of fsync() have requirements
     * about the file access modes that were used when their file descriptor
     * argument was opened, and these requirements differ depending on whether
     * the file descriptor is for a directory.
     *
     * For any file descriptor that may eventually be handed to fsync(), we
     * should have opened it with access modes that are compatible with
     * fsync() on all supported systems, otherwise the code may not be
     * portable, even if it runs ok on the current system.
     *
     * We assert here that a descriptor for a file was opened with write
     * permissions (either O_RDWR or O_WRONLY) and for a directory without
     * write permissions (O_RDONLY).
     *
     * Ignore any fstat errors and let the follow-up fsync() do its work.
     * Doing this sanity check here counts for the case where fsync() is
     * disabled.
     */
    if (fstat(fd, &st) == 0)
    {
        int         desc_flags = fcntl(fd, F_GETFL);

        /*
         * O_RDONLY is historically 0, so just make sure that for directories
         * no write flags are used.
         */
        if (S_ISDIR(st.st_mode))
            Assert((desc_flags & (O_RDWR | O_WRONLY)) == 0);
        else
            Assert((desc_flags & (O_RDWR | O_WRONLY)) != 0);
    }
    errno = 0;
#endif

    /* #if is to skip the sync_method test if there's no need for it */
#if defined(HAVE_FSYNC_WRITETHROUGH) && !defined(FSYNC_WRITETHROUGH_IS_FSYNC)
    if (sync_method == SYNC_METHOD_FSYNC_WRITETHROUGH)
        return pg_fsync_writethrough(fd);
    else
#endif
        return pg_fsync_no_writethrough(fd);
}

pg_fsync_no_writethrough()

int pg_fsync_no_writethrough

(

int

fd

)

Definition at line 402 of file fd.c.

References enableFsync, and fsync.

Referenced by issue_xlog_fsync(), and pg_fsync().

{
    if (enableFsync)
        return fsync(fd);
    else
        return 0;
}

pg_fsync_writethrough()

int pg_fsync_writethrough

(

int

fd

)

Definition at line 414 of file fd.c.

References enableFsync.

Referenced by issue_xlog_fsync(), pg_fsync(), signal_cleanup(), and test_sync().

{
    if (enableFsync)
    {
#ifdef WIN32
        return _commit(fd);
#elif defined(F_FULLFSYNC)
        return (fcntl(fd, F_FULLFSYNC, 0) == -1) ? -1 : 0;
#else
        errno = ENOSYS;
        return -1;
#endif
    }
    else
        return 0;
}

pg_pwritev_with_retry()

ssize_t pg_pwritev_with_retry	(	int	fd,
		const struct iovec *	iov,
		int	iovcnt,
		off_t	offset
	)

Definition at line 3645 of file fd.c.

References Assert, iovec::iov_base, iovec::iov_len, Min, and pg_pwritev().

Referenced by XLogFileInit().

{
    struct iovec iov_copy[PG_IOV_MAX];
    ssize_t     sum = 0;
    ssize_t     part;

    /* We'd better have space to make a copy, in case we need to retry. */
    if (iovcnt > PG_IOV_MAX)
    {
        errno = EINVAL;
        return -1;
    }

    for (;;)
    {
        /* Write as much as we can. */
        part = pg_pwritev(fd, iov, iovcnt, offset);
        if (part < 0)
            return -1;

#ifdef SIMULATE_SHORT_WRITE
        part = Min(part, 4096);
#endif

        /* Count our progress. */
        sum += part;
        offset += part;

        /* Step over iovecs that are done. */
        while (iovcnt > 0 && iov->iov_len <= part)
        {
            part -= iov->iov_len;
            ++iov;
            --iovcnt;
        }

        /* Are they all done? */
        if (iovcnt == 0)
        {
            /* We don't expect the kernel to write more than requested. */
            Assert(part == 0);
            break;
        }

        /*
         * Move whatever's left to the front of our mutable copy and adjust
         * the leading iovec.
         */
        Assert(iovcnt > 0);
        memmove(iov_copy, iov, sizeof(*iov) * iovcnt);
        Assert(iov->iov_len > part);
        iov_copy[0].iov_base = (char *) iov_copy[0].iov_base + part;
        iov_copy[0].iov_len -= part;
        iov = iov_copy;
    }

    return sum;
}

pg_truncate()

int pg_truncate	(	const char *	path,
		off_t	length
	)

Definition at line 630 of file fd.c.

References CloseTransientFile(), vfd::fd, ftruncate, OpenTransientFile(), and PG_BINARY.

Referenced by do_truncate().

{
#ifdef WIN32
    int         save_errno;
    int         ret;
    int         fd;

    fd = OpenTransientFile(path, O_RDWR | PG_BINARY);
    if (fd >= 0)
    {
        ret = ftruncate(fd, 0);
        save_errno = errno;
        CloseTransientFile(fd);
        errno = save_errno;
    }
    else
        ret = -1;

    return ret;
#else
    return truncate(path, length);
#endif
}

ReadDir()

struct dirent* ReadDir	(	DIR *	dir,
		const char *	dirname
	)

Definition at line 2681 of file fd.c.

References ERROR, and ReadDirExtended().

Referenced by calculate_database_size(), calculate_tablespace_size(), CheckPointLogicalRewriteHeap(), CheckPointSnapBuild(), CleanupBackupHistory(), copydir(), db_dir_size(), destroy_tablespace_directories(), directory_is_empty(), do_pg_start_backup(), dsm_cleanup_for_mmap(), extension_file_exists(), get_ext_ver_list(), movedb(), perform_base_backup(), pg_available_extension_versions(), pg_available_extensions(), pg_logdir_ls_internal(), pg_ls_dir(), pg_ls_dir_files(), pg_tablespace_databases(), pg_tzenumerate_next(), pgarch_readyXlog(), pgstat_reset_remove_files(), RemoveNonParentXlogFiles(), RemoveOldXlogFiles(), RemoveTempXlogFiles(), ResetUnloggedRelations(), ResetUnloggedRelationsInDbspaceDir(), ResetUnloggedRelationsInTablespaceDir(), restoreTwoPhaseData(), sendDir(), SlruScanDirectory(), StartupReorderBuffer(), StartupReplicationSlots(), and UpdateLogicalMappings().

{
    return ReadDirExtended(dir, dirname, ERROR);
}

ReadDirExtended()

struct dirent* ReadDirExtended	(	DIR *	dir,
		const char *	dirname,
		int	elevel
	)

Definition at line 2696 of file fd.c.

References ereport, errcode_for_file_access(), errmsg(), and readdir().

Referenced by DeleteAllExportedSnapshotFiles(), ReadDir(), RelationCacheInitFileRemove(), RelationCacheInitFileRemoveInDir(), RemovePgTempFiles(), RemovePgTempFilesInDir(), RemovePgTempRelationFiles(), RemovePgTempRelationFilesInDbspace(), ReorderBufferCleanupSerializedTXNs(), scan_directory_ci(), and walkdir().

{
    struct dirent *dent;

    /* Give a generic message for AllocateDir failure, if caller didn't */
    if (dir == NULL)
    {
        ereport(elevel,
                (errcode_for_file_access(),
                 errmsg("could not open directory \"%s\": %m",
                        dirname)));
        return NULL;
    }

    errno = 0;
    if ((dent = readdir(dir)) != NULL)
        return dent;

    if (errno)
        ereport(elevel,
                (errcode_for_file_access(),
                 errmsg("could not read directory \"%s\": %m",
                        dirname)));
    return NULL;
}

ReleaseExternalFD()

void ReleaseExternalFD

(

void

)

Definition at line 1129 of file fd.c.

References Assert, buf, elog, LOG, vfd::lruLessRecently, numExternalFDs, and snprintf.

Referenced by ClosePostmasterPorts(), connect_pg_server(), createNewConnection(), CreateWaitEventSet(), dblink_connect(), dblink_disconnect(), dblink_exec(), dblink_get_conn(), dblink_record_internal(), dblink_security_check(), disconnect_pg_server(), dsm_impl_op(), FreeWaitEventSet(), InitializeLatchSupport(), and XLogFileClose().

{
    Assert(numExternalFDs > 0);
    numExternalFDs--;
}

RemovePgTempFiles()

void RemovePgTempFiles

(

void

)

Definition at line 3038 of file fd.c.

References AllocateDir(), dirent::d_name, FreeDir(), LOG, MAXPGPATH, PG_TEMP_FILES_DIR, ReadDirExtended(), RemovePgTempFilesInDir(), RemovePgTempRelationFiles(), snprintf, and TABLESPACE_VERSION_DIRECTORY.

Referenced by PostmasterMain().

{
    char        temp_path[MAXPGPATH + 10 + sizeof(TABLESPACE_VERSION_DIRECTORY) + sizeof(PG_TEMP_FILES_DIR)];
    DIR        *spc_dir;
    struct dirent *spc_de;

    /*
     * First process temp files in pg_default ($PGDATA/base)
     */
    snprintf(temp_path, sizeof(temp_path), "base/%s", PG_TEMP_FILES_DIR);
    RemovePgTempFilesInDir(temp_path, true, false);
    RemovePgTempRelationFiles("base");

    /*
     * Cycle through temp directories for all non-default tablespaces.
     */
    spc_dir = AllocateDir("pg_tblspc");

    while ((spc_de = ReadDirExtended(spc_dir, "pg_tblspc", LOG)) != NULL)
    {
        if (strcmp(spc_de->d_name, ".") == 0 ||
            strcmp(spc_de->d_name, "..") == 0)
            continue;

        snprintf(temp_path, sizeof(temp_path), "pg_tblspc/%s/%s/%s",
                 spc_de->d_name, TABLESPACE_VERSION_DIRECTORY, PG_TEMP_FILES_DIR);
        RemovePgTempFilesInDir(temp_path, true, false);

        snprintf(temp_path, sizeof(temp_path), "pg_tblspc/%s/%s",
                 spc_de->d_name, TABLESPACE_VERSION_DIRECTORY);
        RemovePgTempRelationFiles(temp_path);
    }

    FreeDir(spc_dir);

    /*
     * In EXEC_BACKEND case there is a pgsql_tmp directory at the top level of
     * DataDir as well.  However, that is *not* cleaned here because doing so
     * would create a race condition.  It's done separately, earlier in
     * postmaster startup.
     */
}

RemovePgTempFilesInDir()

void RemovePgTempFilesInDir	(	const char *	tmpdirname,
		bool	missing_ok,
		bool	unlink_all
	)

Definition at line 3097 of file fd.c.

References AllocateDir(), dirent::d_name, ereport, errcode_for_file_access(), errmsg(), FreeDir(), LOG, lstat, MAXPGPATH, PG_TEMP_FILE_PREFIX, ReadDirExtended(), RemovePgTempFilesInDir(), S_ISDIR, snprintf, and stat::st_mode.

Referenced by PostmasterMain(), RemovePgTempFiles(), and RemovePgTempFilesInDir().

{
    DIR        *temp_dir;
    struct dirent *temp_de;
    char        rm_path[MAXPGPATH * 2];

    temp_dir = AllocateDir(tmpdirname);

    if (temp_dir == NULL && errno == ENOENT && missing_ok)
        return;

    while ((temp_de = ReadDirExtended(temp_dir, tmpdirname, LOG)) != NULL)
    {
        if (strcmp(temp_de->d_name, ".") == 0 ||
            strcmp(temp_de->d_name, "..") == 0)
            continue;

        snprintf(rm_path, sizeof(rm_path), "%s/%s",
                 tmpdirname, temp_de->d_name);

        if (unlink_all ||
            strncmp(temp_de->d_name,
                    PG_TEMP_FILE_PREFIX,
                    strlen(PG_TEMP_FILE_PREFIX)) == 0)
        {
            struct stat statbuf;

            if (lstat(rm_path, &statbuf) < 0)
            {
                ereport(LOG,
                        (errcode_for_file_access(),
                         errmsg("could not stat file \"%s\": %m", rm_path)));
                continue;
            }

            if (S_ISDIR(statbuf.st_mode))
            {
                /* recursively remove contents, then directory itself */
                RemovePgTempFilesInDir(rm_path, false, true);

                if (rmdir(rm_path) < 0)
                    ereport(LOG,
                            (errcode_for_file_access(),
                             errmsg("could not remove directory \"%s\": %m",
                                    rm_path)));
            }
            else
            {
                if (unlink(rm_path) < 0)
                    ereport(LOG,
                            (errcode_for_file_access(),
                             errmsg("could not remove file \"%s\": %m",
                                    rm_path)));
            }
        }
        else
            ereport(LOG,
                    (errmsg("unexpected file found in temporary-files directory: \"%s\"",
                            rm_path)));
    }

    FreeDir(temp_dir);
}

ReserveExternalFD()

void ReserveExternalFD

(

void

)

Definition at line 1111 of file fd.c.

References numExternalFDs, and ReleaseLruFiles().

Referenced by AcquireExternalFD(), BackendInitialize(), dsm_impl_op(), InitializeLatchSupport(), InitPostmasterDeathWatchHandle(), pgstat_init(), PostmasterMarkPIDForWorkerNotify(), and XLogWrite().

{
    /*
     * Release VFDs if needed to stay safe.  Because we do this before
     * incrementing numExternalFDs, the final state will be as desired, i.e.,
     * nfile + numAllocatedDescs + numExternalFDs <= max_safe_fds.
     */
    ReleaseLruFiles();

    numExternalFDs++;
}

set_max_safe_fds()

void set_max_safe_fds

(

void

)

Definition at line 971 of file fd.c.

References count_usable_fds(), DEBUG2, elog, ereport, errcode(), errdetail(), errmsg(), FATAL, FD_MINFREE, max_files_per_process, max_safe_fds, Min, and NUM_RESERVED_FDS.

Referenced by PostmasterMain().

{
    int         usable_fds;
    int         already_open;

    /*----------
     * We want to set max_safe_fds to
     *          MIN(usable_fds, max_files_per_process - already_open)
     * less the slop factor for files that are opened without consulting
     * fd.c.  This ensures that we won't exceed either max_files_per_process
     * or the experimentally-determined EMFILE limit.
     *----------
     */
    count_usable_fds(max_files_per_process,
                     &usable_fds, &already_open);

    max_safe_fds = Min(usable_fds, max_files_per_process - already_open);

    /*
     * Take off the FDs reserved for system() etc.
     */
    max_safe_fds -= NUM_RESERVED_FDS;

    /*
     * Make sure we still have enough to get by.
     */
    if (max_safe_fds < FD_MINFREE)
        ereport(FATAL,
                (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
                 errmsg("insufficient file descriptors available to start server process"),
                 errdetail("System allows %d, we need at least %d.",
                           max_safe_fds + NUM_RESERVED_FDS,
                           FD_MINFREE + NUM_RESERVED_FDS)));

    elog(DEBUG2, "max_safe_fds = %d, usable_fds = %d, already_open = %d",
         max_safe_fds, usable_fds, already_open);
}

SetTempTablespaces()

void SetTempTablespaces	(	Oid *	tableSpaces,
		int	numSpaces
	)

Definition at line 2821 of file fd.c.

References Assert, nextTempTableSpace, numTempTableSpaces, random(), and tempTableSpaces.

Referenced by assign_temp_tablespaces(), and PrepareTempTablespaces().

{
    Assert(numSpaces >= 0);
    tempTableSpaces = tableSpaces;
    numTempTableSpaces = numSpaces;

    /*
     * Select a random starting point in the list.  This is to minimize
     * conflicts between backends that are most likely sharing the same list
     * of temp tablespaces.  Note that if we create multiple temp files in the
     * same transaction, we'll advance circularly through the list --- this
     * ensures that large temporary sort files are nicely spread across all
     * available tablespaces.
     */
    if (numSpaces > 1)
        nextTempTableSpace = random() % numSpaces;
    else
        nextTempTableSpace = 0;
}

SyncDataDirectory()

void SyncDataDirectory

(

void

)

Definition at line 3289 of file fd.c.

References datadir_fsync_fname(), DEBUG1, enableFsync, ereport, errcode_for_file_access(), errmsg(), LOG, lstat, pgwin32_is_junction(), stat::st_mode, and walkdir().

Referenced by StartupXLOG().

{
    bool        xlog_is_symlink;

    /* We can skip this whole thing if fsync is disabled. */
    if (!enableFsync)
        return;

    /*
     * If pg_wal is a symlink, we'll need to recurse into it separately,
     * because the first walkdir below will ignore it.
     */
    xlog_is_symlink = false;

#ifndef WIN32
    {
        struct stat st;

        if (lstat("pg_wal", &st) < 0)
            ereport(LOG,
                    (errcode_for_file_access(),
                     errmsg("could not stat file \"%s\": %m",
                            "pg_wal")));
        else if (S_ISLNK(st.st_mode))
            xlog_is_symlink = true;
    }
#else
    if (pgwin32_is_junction("pg_wal"))
        xlog_is_symlink = true;
#endif

    /*
     * If possible, hint to the kernel that we're soon going to fsync the data
     * directory and its contents.  Errors in this step are even less
     * interesting than normal, so log them only at DEBUG1.
     */
#ifdef PG_FLUSH_DATA_WORKS
    walkdir(".", pre_sync_fname, false, DEBUG1);
    if (xlog_is_symlink)
        walkdir("pg_wal", pre_sync_fname, false, DEBUG1);
    walkdir("pg_tblspc", pre_sync_fname, true, DEBUG1);
#endif

    /*
     * Now we do the fsync()s in the same order.
     *
     * The main call ignores symlinks, so in addition to specially processing
     * pg_wal if it's a symlink, pg_tblspc has to be visited separately with
     * process_symlinks = true.  Note that if there are any plain directories
     * in pg_tblspc, they'll get fsync'd twice.  That's not an expected case
     * so we don't worry about optimizing it.
     */
    walkdir(".", datadir_fsync_fname, false, LOG);
    if (xlog_is_symlink)
        walkdir("pg_wal", datadir_fsync_fname, false, LOG);
    walkdir("pg_tblspc", datadir_fsync_fname, true, LOG);
}

TempTablespacePath()

void TempTablespacePath	(	char *	path,
		Oid	tablespace
	)

Definition at line 1659 of file fd.c.

References InvalidOid, MAXPGPATH, PG_TEMP_FILES_DIR, snprintf, and TABLESPACE_VERSION_DIRECTORY.

Referenced by OpenTemporaryFileInTablespace(), pg_ls_tmpdir(), SharedFileSetCreate(), and SharedFileSetPath().

{
    /*
     * Identify the tempfile directory for this tablespace.
     *
     * If someone tries to specify pg_global, use pg_default instead.
     */
    if (tablespace == InvalidOid ||
        tablespace == DEFAULTTABLESPACE_OID ||
        tablespace == GLOBALTABLESPACE_OID)
        snprintf(path, MAXPGPATH, "base/%s", PG_TEMP_FILES_DIR);
    else
    {
        /* All other tablespaces are accessed via symlinks */
        snprintf(path, MAXPGPATH, "pg_tblspc/%u/%s/%s",
                 tablespace, TABLESPACE_VERSION_DIRECTORY,
                 PG_TEMP_FILES_DIR);
    }
}

TempTablespacesAreSet()

bool TempTablespacesAreSet

(

void

)

Definition at line 2849 of file fd.c.

References numTempTableSpaces.

Referenced by GetTempTablespaces(), and PrepareTempTablespaces().

{
    return (numTempTableSpaces >= 0);
}

Variable Documentation

data_sync_retry

PGDLLIMPORT bool data_sync_retry

Definition at line 159 of file fd.c.

Referenced by data_sync_elevel().

max_files_per_process

PGDLLIMPORT int max_files_per_process

Definition at line 143 of file fd.c.

Referenced by set_max_safe_fds().

max_safe_fds

int max_safe_fds

Definition at line 156 of file fd.c.

Referenced by AcquireExternalFD(), PostmasterMarkPIDForWorkerNotify(), ReleaseLruFiles(), reserveAllocatedDesc(), and set_max_safe_fds().