Header And Logo
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#include "postgres.h"#include <fcntl.h>#include <unistd.h>#include <sys/stat.h>#include "storage/copydir.h"#include "storage/fd.h"#include "miscadmin.h"
Go to the source code of this file.
Defines | |
| #define | COPY_BUF_SIZE (8 * BLCKSZ) |
Functions | |
| static void | fsync_fname (char *fname, bool isdir) |
| void | copydir (char *fromdir, char *todir, bool recurse) |
| void | copy_file (char *fromfile, char *tofile) |
| #define COPY_BUF_SIZE (8 * BLCKSZ) |
| void copy_file | ( | char * | fromfile, | |
| char * | tofile | |||
| ) |
Definition at line 138 of file copydir.c.
References CHECK_FOR_INTERRUPTS, CloseTransientFile(), COPY_BUF_SIZE, ereport, errcode_for_file_access(), errmsg(), ERROR, OpenTransientFile(), palloc(), pfree(), PG_BINARY, pg_flush_data(), read, and write.
{
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 = OpenTransientFile(fromfile, O_RDONLY | PG_BINARY, 0);
if (srcfd < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\": %m", fromfile)));
dstfd = OpenTransientFile(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)
{
/* If we got a cancel signal during the copy of the file, quit */
CHECK_FOR_INTERRUPTS();
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. Ignore any error, since it's only a hint.
*/
(void) pg_flush_data(dstfd, offset, nbytes);
}
if (CloseTransientFile(dstfd))
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not close file \"%s\": %m", tofile)));
CloseTransientFile(srcfd);
pfree(buffer);
}
| void copydir | ( | char * | fromdir, | |
| char * | todir, | |||
| bool | recurse | |||
| ) |
Definition at line 40 of file copydir.c.
References AllocateDir(), CHECK_FOR_INTERRUPTS, copy_file(), copydir(), dirent::d_name, enableFsync, ereport, errcode_for_file_access(), errmsg(), ERROR, FreeDir(), fsync_fname(), lstat, MAXPGPATH, mkdir, NULL, ReadDir(), and snprintf().
Referenced by copydir(), createdb(), dbase_redo(), and movedb().
{
DIR *xldir;
struct dirent *xlde;
char fromfile[MAXPGPATH];
char tofile[MAXPGPATH];
if (mkdir(todir, S_IRWXU) != 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 we got a cancel signal during the copy of the directory, quit */
CHECK_FOR_INTERRUPTS();
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.
* But if fsync is disabled, we're done.
*/
if (!enableFsync)
return;
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, false);
}
FreeDir(xldir);
/*
* 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.
*/
fsync_fname(todir, true);
}
| static void fsync_fname | ( | char * | fname, | |
| bool | isdir | |||
| ) | [static] |
Definition at line 219 of file copydir.c.
References CloseTransientFile(), ereport, errcode_for_file_access(), errmsg(), ERROR, OpenTransientFile(), PG_BINARY, and pg_fsync().
Referenced by copydir().
{
int fd;
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
*/
if (!isdir)
fd = OpenTransientFile(fname,
O_RDWR | PG_BINARY,
S_IRUSR | S_IWUSR);
else
fd = OpenTransientFile(fname,
O_RDONLY | PG_BINARY,
S_IRUSR | S_IWUSR);
/*
* Some OSs don't allow us to open directories at all (Windows returns
* EACCES)
*/
if (fd < 0 && isdir && (errno == EISDIR || errno == EACCES))
return;
else if (fd < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\": %m", fname)));
returncode = pg_fsync(fd);
/* Some OSs don't allow us to fsync directories at all */
if (returncode != 0 && isdir && errno == EBADF)
{
CloseTransientFile(fd);
return;
}
if (returncode != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not fsync file \"%s\": %m", fname)));
CloseTransientFile(fd);
}
1.7.1