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/*-------------------------------------------------------------------------
*
* copydir.c
* copies a directory
*
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* While "xcopy /e /i /q" works fine for copying directories, on Windows XP
* it requires a Window handle which prevents it from working when invoked
* as a service.
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/port/copydir.c,v 1.31 2010/02/22 15:29:46 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include "storage/fd.h"
/*
* On Windows, call non-macro versions of palloc; we can't reference
* CurrentMemoryContext in this file because of PGDLLIMPORT conflict.
*/
#if defined(WIN32) || defined(__CYGWIN__)
#undef palloc
#undef pstrdup
#define palloc(sz) pgport_palloc(sz)
#define pstrdup(str) pgport_pstrdup(str)
#endif
static void copy_file(char *fromfile, char *tofile);
static void fsync_fname(char *fname);
/*
* copydir: copy a directory
*
* If recurse is false, subdirectories are ignored. Anything that's not
* a directory or a regular file is ignored.
*/
void
copydir(char *fromdir, char *todir, bool recurse)
{
DIR *xldir;
struct dirent *xlde;
char fromfile[MAXPGPATH];
char tofile[MAXPGPATH];
if (mkdir(todir, S_IRUSR | S_IWUSR | S_IXUSR) != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create directory \"%s\": %m", todir)));
xldir = AllocateDir(fromdir);
if (xldir == NULL)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open directory \"%s\": %m", fromdir)));
while ((xlde = ReadDir(xldir, fromdir)) != NULL)
{
struct stat fst;
if (strcmp(xlde->d_name, ".") == 0 ||
strcmp(xlde->d_name, "..") == 0)
continue;
snprintf(fromfile, MAXPGPATH, "%s/%s", fromdir, xlde->d_name);
snprintf(tofile, MAXPGPATH, "%s/%s", todir, xlde->d_name);
if (lstat(fromfile, &fst) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not stat file \"%s\": %m", fromfile)));
if (S_ISDIR(fst.st_mode))
{
/* recurse to handle subdirectories */
if (recurse)
copydir(fromfile, tofile, true);
}
else if (S_ISREG(fst.st_mode))
copy_file(fromfile, tofile);
}
FreeDir(xldir);
/*
* Be paranoid here and fsync all files to ensure the copy is really done.
*/
xldir = AllocateDir(todir);
if (xldir == NULL)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open directory \"%s\": %m", todir)));
while ((xlde = ReadDir(xldir, todir)) != NULL)
{
struct stat fst;
if (strcmp(xlde->d_name, ".") == 0 ||
strcmp(xlde->d_name, "..") == 0)
continue;
snprintf(tofile, MAXPGPATH, "%s/%s", todir, xlde->d_name);
/*
* We don't need to sync subdirectories here since the recursive
* copydir will do it before it returns
*/
if (lstat(tofile, &fst) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not stat file \"%s\": %m", tofile)));
if (S_ISREG(fst.st_mode))
fsync_fname(tofile);
}
FreeDir(xldir);
#ifdef NOTYET
/*
* It's important to fsync the destination directory itself as
* individual file fsyncs don't guarantee that the directory entry
* for the file is synced. Recent versions of ext4 have made the
* window much wider but it's been true for ext3 and other
* filesystems in the past.
*
* However we can't do this just yet, it has portability issues.
*/
fsync_fname(todir);
#endif
}
/*
* copy one file
*/
static void
copy_file(char *fromfile, char *tofile)
{
char *buffer;
int srcfd;
int dstfd;
int nbytes;
off_t offset;
/* Use palloc to ensure we get a maxaligned buffer */
#define COPY_BUF_SIZE (8 * BLCKSZ)
buffer = palloc(COPY_BUF_SIZE);
/*
* Open the files
*/
srcfd = BasicOpenFile(fromfile, O_RDONLY | PG_BINARY, 0);
if (srcfd < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\": %m", fromfile)));
dstfd = BasicOpenFile(tofile, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
S_IRUSR | S_IWUSR);
if (dstfd < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create file \"%s\": %m", tofile)));
/*
* Do the data copying.
*/
for (offset=0; ; offset+=nbytes)
{
nbytes = read(srcfd, buffer, COPY_BUF_SIZE);
if (nbytes < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not read file \"%s\": %m", fromfile)));
if (nbytes == 0)
break;
errno = 0;
if ((int) write(dstfd, buffer, nbytes) != nbytes)
{
/* if write didn't set errno, assume problem is no disk space */
if (errno == 0)
errno = ENOSPC;
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not write to file \"%s\": %m", tofile)));
}
/*
* We fsync the files later but first flush them to avoid spamming
* the cache and hopefully get the kernel to start writing them
* out before the fsync comes.
*/
pg_flush_data(dstfd, offset, nbytes);
}
if (close(dstfd))
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not close file \"%s\": %m", tofile)));
close(srcfd);
pfree(buffer);
}
/*
* fsync a file
*/
static void
fsync_fname(char *fname)
{
int fd = BasicOpenFile(fname,
O_RDONLY | PG_BINARY,
S_IRUSR | S_IWUSR);
if (fd < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\": %m", fname)));
errno = 0;
if (pg_fsync(fd) != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not fsync file \"%s\": %m", fname)));
close(fd);
}
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