file.c File Reference

#include "postgres_fe.h"
#include <sys/stat.h>
#include <fcntl.h>
#include "access/visibilitymapdefs.h"
#include "common/file_perm.h"
#include "pg_upgrade.h"
#include "storage/bufpage.h"
#include "storage/checksum.h"
#include "storage/checksum_impl.h"

Include dependency graph for file.c:

Go to the source code of this file.

Macros
#define	COPY_BUF_SIZE   (50 * BLCKSZ)

Functions
void	cloneFile (const char *src, const char *dst, const char *schemaName, const char *relName)
void	copyFile (const char *src, const char *dst, const char *schemaName, const char *relName)
void	linkFile (const char *src, const char *dst, const char *schemaName, const char *relName)
void	rewriteVisibilityMap (const char *fromfile, const char *tofile, const char *schemaName, const char *relName)
void	check_file_clone (void)
void	check_hard_link (void)

Macro Definition Documentation

COPY_BUF_SIZE

#define COPY_BUF_SIZE   (50 * BLCKSZ)

Function Documentation

check_file_clone()

void check_file_clone

(

void

)

Definition at line 320 of file file.c.

{
    char        existing_file[MAXPGPATH];
    char        new_link_file[MAXPGPATH];
 
    snprintf(existing_file, sizeof(existing_file), "%s/PG_VERSION", old_cluster.pgdata);
    snprintf(new_link_file, sizeof(new_link_file), "%s/PG_VERSION.clonetest", new_cluster.pgdata);
    unlink(new_link_file);      /* might fail */
 
#if defined(HAVE_COPYFILE) && defined(COPYFILE_CLONE_FORCE)
    if (copyfile(existing_file, new_link_file, NULL, COPYFILE_CLONE_FORCE) < 0)
        pg_fatal("could not clone file between old and new data directories: %s",
                 strerror(errno));
#elif defined(__linux__) && defined(FICLONE)
    {
        int         src_fd;
        int         dest_fd;
 
        if ((src_fd = open(existing_file, O_RDONLY | PG_BINARY, 0)) < 0)
            pg_fatal("could not open file \"%s\": %s",
                     existing_file, strerror(errno));
 
        if ((dest_fd = open(new_link_file, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
                            pg_file_create_mode)) < 0)
            pg_fatal("could not create file \"%s\": %s",
                     new_link_file, strerror(errno));
 
        if (ioctl(dest_fd, FICLONE, src_fd) < 0)
            pg_fatal("could not clone file between old and new data directories: %s",
                     strerror(errno));
 
        close(src_fd);
        close(dest_fd);
    }
#else
    pg_fatal("file cloning not supported on this platform");
#endif
 
    unlink(new_link_file);
}

References close, MAXPGPATH, new_cluster, old_cluster, PG_BINARY, pg_fatal, pg_file_create_mode, ClusterInfo::pgdata, snprintf, and strerror.

Referenced by check_new_cluster().

check_hard_link()

void check_hard_link

(

void

)

Definition at line 362 of file file.c.

{
    char        existing_file[MAXPGPATH];
    char        new_link_file[MAXPGPATH];
 
    snprintf(existing_file, sizeof(existing_file), "%s/PG_VERSION", old_cluster.pgdata);
    snprintf(new_link_file, sizeof(new_link_file), "%s/PG_VERSION.linktest", new_cluster.pgdata);
    unlink(new_link_file);      /* might fail */
 
    if (link(existing_file, new_link_file) < 0)
        pg_fatal("could not create hard link between old and new data directories: %s\n"
                 "In link mode the old and new data directories must be on the same file system.",
                 strerror(errno));
 
    unlink(new_link_file);
}

References link(), MAXPGPATH, new_cluster, old_cluster, pg_fatal, ClusterInfo::pgdata, snprintf, and strerror.

Referenced by check_new_cluster().

cloneFile()

void cloneFile	(	const char *	src,
		const char *	dst,
		const char *	schemaName,
		const char *	relName
	)

Definition at line 38 of file file.c.

{
#if defined(HAVE_COPYFILE) && defined(COPYFILE_CLONE_FORCE)
    if (copyfile(src, dst, NULL, COPYFILE_CLONE_FORCE) < 0)
        pg_fatal("error while cloning relation \"%s.%s\" (\"%s\" to \"%s\"): %s",
                 schemaName, relName, src, dst, strerror(errno));
#elif defined(__linux__) && defined(FICLONE)
    int         src_fd;
    int         dest_fd;
 
    if ((src_fd = open(src, O_RDONLY | PG_BINARY, 0)) < 0)
        pg_fatal("error while cloning relation \"%s.%s\": could not open file \"%s\": %s",
                 schemaName, relName, src, strerror(errno));
 
    if ((dest_fd = open(dst, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
                        pg_file_create_mode)) < 0)
        pg_fatal("error while cloning relation \"%s.%s\": could not create file \"%s\": %s",
                 schemaName, relName, dst, strerror(errno));
 
    if (ioctl(dest_fd, FICLONE, src_fd) < 0)
    {
        int         save_errno = errno;
 
        unlink(dst);
 
        pg_fatal("error while cloning relation \"%s.%s\" (\"%s\" to \"%s\"): %s",
                 schemaName, relName, src, dst, strerror(save_errno));
    }
 
    close(src_fd);
    close(dest_fd);
#endif
}

References close, PG_BINARY, pg_fatal, pg_file_create_mode, and strerror.

Referenced by transfer_relfile().

copyFile()

void copyFile	(	const char *	src,
		const char *	dst,
		const char *	schemaName,
		const char *	relName
	)

Definition at line 81 of file file.c.

{
#ifndef WIN32
    int         src_fd;
    int         dest_fd;
    char       *buffer;
 
    if ((src_fd = open(src, O_RDONLY | PG_BINARY, 0)) < 0)
        pg_fatal("error while copying relation \"%s.%s\": could not open file \"%s\": %s",
                 schemaName, relName, src, strerror(errno));
 
    if ((dest_fd = open(dst, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
                        pg_file_create_mode)) < 0)
        pg_fatal("error while copying relation \"%s.%s\": could not create file \"%s\": %s",
                 schemaName, relName, dst, strerror(errno));
 
    /* copy in fairly large chunks for best efficiency */
#define COPY_BUF_SIZE (50 * BLCKSZ)
 
    buffer = (char *) pg_malloc(COPY_BUF_SIZE);
 
    /* perform data copying i.e read src source, write to destination */
    while (true)
    {
        ssize_t     nbytes = read(src_fd, buffer, COPY_BUF_SIZE);
 
        if (nbytes < 0)
            pg_fatal("error while copying relation \"%s.%s\": could not read file \"%s\": %s",
                     schemaName, relName, src, strerror(errno));
 
        if (nbytes == 0)
            break;
 
        errno = 0;
        if (write(dest_fd, buffer, nbytes) != nbytes)
        {
            /* if write didn't set errno, assume problem is no disk space */
            if (errno == 0)
                errno = ENOSPC;
            pg_fatal("error while copying relation \"%s.%s\": could not write file \"%s\": %s",
                     schemaName, relName, dst, strerror(errno));
        }
    }
 
    pg_free(buffer);
    close(src_fd);
    close(dest_fd);
 
#else                           /* WIN32 */
 
    if (CopyFile(src, dst, true) == 0)
    {
        _dosmaperr(GetLastError());
        pg_fatal("error while copying relation \"%s.%s\" (\"%s\" to \"%s\"): %s",
                 schemaName, relName, src, dst, strerror(errno));
    }
 
#endif                          /* WIN32 */
}

References _dosmaperr(), close, COPY_BUF_SIZE, PG_BINARY, pg_fatal, pg_file_create_mode, pg_free(), pg_malloc(), read, strerror, and write.

Referenced by transfer_relfile().

linkFile()

void linkFile	(	const char *	src,
		const char *	dst,
		const char *	schemaName,
		const char *	relName
	)

Definition at line 150 of file file.c.

{
    if (link(src, dst) < 0)
        pg_fatal("error while creating link for relation \"%s.%s\" (\"%s\" to \"%s\"): %s",
                 schemaName, relName, src, dst, strerror(errno));
}

References link(), pg_fatal, and strerror.

Referenced by transfer_relfile().

rewriteVisibilityMap()

void rewriteVisibilityMap	(	const char *	fromfile,
		const char *	tofile,
		const char *	schemaName,
		const char *	relName
	)

Definition at line 176 of file file.c.

{
    int         src_fd;
    int         dst_fd;
    PGAlignedBlock buffer;
    PGAlignedBlock new_vmbuf;
    ssize_t     totalBytesRead = 0;
    ssize_t     src_filesize;
    int         rewriteVmBytesPerPage;
    BlockNumber new_blkno = 0;
    struct stat statbuf;
 
    /* Compute number of old-format bytes per new page */
    rewriteVmBytesPerPage = (BLCKSZ - SizeOfPageHeaderData) / 2;
 
    if ((src_fd = open(fromfile, O_RDONLY | PG_BINARY, 0)) < 0)
        pg_fatal("error while copying relation \"%s.%s\": could not open file \"%s\": %s",
                 schemaName, relName, fromfile, strerror(errno));
 
    if (fstat(src_fd, &statbuf) != 0)
        pg_fatal("error while copying relation \"%s.%s\": could not stat file \"%s\": %s",
                 schemaName, relName, fromfile, strerror(errno));
 
    if ((dst_fd = open(tofile, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
                       pg_file_create_mode)) < 0)
        pg_fatal("error while copying relation \"%s.%s\": could not create file \"%s\": %s",
                 schemaName, relName, tofile, strerror(errno));
 
    /* Save old file size */
    src_filesize = statbuf.st_size;
 
    /*
     * Turn each visibility map page into 2 pages one by one. Each new page
     * has the same page header as the old one.  If the last section of the
     * last page is empty, we skip it, mostly to avoid turning one-page
     * visibility maps for small relations into two pages needlessly.
     */
    while (totalBytesRead < src_filesize)
    {
        ssize_t     bytesRead;
        char       *old_cur;
        char       *old_break;
        char       *old_blkend;
        PageHeaderData pageheader;
        bool        old_lastblk;
 
        if ((bytesRead = read(src_fd, buffer.data, BLCKSZ)) != BLCKSZ)
        {
            if (bytesRead < 0)
                pg_fatal("error while copying relation \"%s.%s\": could not read file \"%s\": %s",
                         schemaName, relName, fromfile, strerror(errno));
            else
                pg_fatal("error while copying relation \"%s.%s\": partial page found in file \"%s\"",
                         schemaName, relName, fromfile);
        }
 
        totalBytesRead += BLCKSZ;
        old_lastblk = (totalBytesRead == src_filesize);
 
        /* Save the page header data */
        memcpy(&pageheader, buffer.data, SizeOfPageHeaderData);
 
        /*
         * These old_* variables point to old visibility map page. old_cur
         * points to current position on old page. old_blkend points to end of
         * old block.  old_break is the end+1 position on the old page for the
         * data that will be transferred to the current new page.
         */
        old_cur = buffer.data + SizeOfPageHeaderData;
        old_blkend = buffer.data + bytesRead;
        old_break = old_cur + rewriteVmBytesPerPage;
 
        while (old_break <= old_blkend)
        {
            char       *new_cur;
            bool        empty = true;
            bool        old_lastpart;
 
            /* First, copy old page header to new page */
            memcpy(new_vmbuf.data, &pageheader, SizeOfPageHeaderData);
 
            /* Rewriting the last part of the last old page? */
            old_lastpart = old_lastblk && (old_break == old_blkend);
 
            new_cur = new_vmbuf.data + SizeOfPageHeaderData;
 
            /* Process old page bytes one by one, and turn it into new page. */
            while (old_cur < old_break)
            {
                uint8       byte = *(uint8 *) old_cur;
                uint16      new_vmbits = 0;
                int         i;
 
                /* Generate new format bits while keeping old information */
                for (i = 0; i < BITS_PER_BYTE; i++)
                {
                    if (byte & (1 << i))
                    {
                        empty = false;
                        new_vmbits |=
                            VISIBILITYMAP_ALL_VISIBLE << (BITS_PER_HEAPBLOCK * i);
                    }
                }
 
                /* Copy new visibility map bytes to new-format page */
                new_cur[0] = (char) (new_vmbits & 0xFF);
                new_cur[1] = (char) (new_vmbits >> 8);
 
                old_cur++;
                new_cur += BITS_PER_HEAPBLOCK;
            }
 
            /* If the last part of the last page is empty, skip writing it */
            if (old_lastpart && empty)
                break;
 
            /* Set new checksum for visibility map page, if enabled */
            if (new_cluster.controldata.data_checksum_version != 0)
                ((PageHeader) new_vmbuf.data)->pd_checksum =
                    pg_checksum_page(new_vmbuf.data, new_blkno);
 
            errno = 0;
            if (write(dst_fd, new_vmbuf.data, BLCKSZ) != BLCKSZ)
            {
                /* if write didn't set errno, assume problem is no disk space */
                if (errno == 0)
                    errno = ENOSPC;
                pg_fatal("error while copying relation \"%s.%s\": could not write file \"%s\": %s",
                         schemaName, relName, tofile, strerror(errno));
            }
 
            /* Advance for next new page */
            old_break += rewriteVmBytesPerPage;
            new_blkno++;
        }
    }
 
    /* Clean up */
    close(dst_fd);
    close(src_fd);
}

References BITS_PER_BYTE, BITS_PER_HEAPBLOCK, close, ClusterInfo::controldata, PGAlignedBlock::data, ControlData::data_checksum_version, fstat, i, new_cluster, PG_BINARY, pg_checksum_page(), pg_fatal, pg_file_create_mode, read, SizeOfPageHeaderData, stat::st_size, strerror, VISIBILITYMAP_ALL_VISIBLE, and write.

Referenced by transfer_relfile().