static void
execute_pagemap(datapagemap_t *pagemap, const char *path)
{
datapagemap_iterator_t *iter;
BlockNumber blkno;
iter = datapagemap_iterate(pagemap);
while (datapagemap_next(iter, &blkno))
{
off_t offset = blkno * BLCKSZ;
copy_file_range(path, offset, offset + BLCKSZ);
}
}
static void
execute_pagemap(datapagemap_t *pagemap, const char *path)
{
datapagemap_iterator_t *iter;
BlockNumber blkno;
iter = datapagemap_iterate(pagemap);
while (datapagemap_next(iter, &blkno))
{
off_t offset = blkno * BLCKSZ;
copy_file_range(path, offset, offset + BLCKSZ, false);
/* Ok, this block has now been copied from new data dir to old */
}
}
/*
* Calculate the totals needed for progress reports.
*/
void
calculate_totals(void)
{
file_entry_t *entry;
int i;
filemap_t *map = filemap;
map->total_size = 0;
map->fetch_size = 0;
for (i = 0; i < map->narray; i++)
{
entry = map->array[i];
if (entry->type != FILE_TYPE_REGULAR)
continue;
map->total_size += entry->newsize;
if (entry->action == FILE_ACTION_COPY)
{
map->fetch_size += entry->newsize;
continue;
}
if (entry->action == FILE_ACTION_COPY_TAIL)
map->fetch_size += (entry->newsize - entry->oldsize);
if (entry->pagemap.bitmapsize > 0)
{
datapagemap_iterator_t *iter;
BlockNumber blk;
iter = datapagemap_iterate(&entry->pagemap);
while (datapagemap_next(iter, &blk))
map->fetch_size += BLCKSZ;
pg_free(iter);
}
}
}
/*
* Backup data file in the from_root directory to the to_root directory with
* same relative path.
* If lsn is not NULL, pages only which are modified after the lsn will be
* copied.
*/
bool
backup_data_file(const char *from_root, const char *to_root,
pgFile *file, const XLogRecPtr *lsn)
{
char to_path[MAXPGPATH];
FILE *in;
FILE *out;
BackupPageHeader header;
DataPage page; /* used as read buffer */
BlockNumber blknum = 0;
size_t read_len = 0;
pg_crc32 crc;
off_t offset;
INIT_CRC32C(crc);
/* reset size summary */
file->read_size = 0;
file->write_size = 0;
/* open backup mode file for read */
in = fopen(file->path, "r");
if (in == NULL)
{
FIN_CRC32C(crc);
file->crc = crc;
/* maybe vanished, it's not error */
if (errno == ENOENT)
return false;
elog(ERROR, "cannot open backup mode file \"%s\": %s",
file->path, strerror(errno));
}
/* open backup file for write */
if (check)
snprintf(to_path, lengthof(to_path), "%s/tmp", backup_path);
else
join_path_components(to_path, to_root, file->path + strlen(from_root) + 1);
out = fopen(to_path, "w");
if (out == NULL)
{
int errno_tmp = errno;
fclose(in);
elog(ERROR, "cannot open backup file \"%s\": %s",
to_path, strerror(errno_tmp));
}
/* confirm server version */
check_server_version();
/*
* Read each page and write the page excluding hole. If it has been
* determined that the page can be copied safely, but no page map
* has been built, it means that we are in presence of a relation
* file that needs to be completely scanned. If a page map is present
* only scan the blocks needed. In each case, pages are copied without
* their hole to ensure some basic level of compression.
*/
if (file->pagemap.bitmapsize == 0)
{
for (blknum = 0;
(read_len = fread(&page, 1, sizeof(page), in)) == sizeof(page);
++blknum)
{
XLogRecPtr page_lsn;
int upper_offset;
int upper_length;
header.block = blknum;
/*
* If an invalid data page was found, fallback to simple copy to ensure
* all pages in the file don't have BackupPageHeader.
*/
if (!parse_page(&page, &page_lsn,
&header.hole_offset, &header.hole_length))
{
elog(LOG, "%s fall back to simple copy", file->path);
fclose(in);
fclose(out);
file->is_datafile = false;
return copy_file(from_root, to_root, file);
}
file->read_size += read_len;
/* if the page has not been modified since last backup, skip it */
if (lsn && !XLogRecPtrIsInvalid(page_lsn) && page_lsn < *lsn)
continue;
upper_offset = header.hole_offset + header.hole_length;
upper_length = BLCKSZ - upper_offset;
/* write data page excluding hole */
if (fwrite(&header, 1, sizeof(header), out) != sizeof(header) ||
fwrite(page.data, 1, header.hole_offset, out) != header.hole_offset ||
fwrite(page.data + upper_offset, 1, upper_length, out) != upper_length)
{
int errno_tmp = errno;
/* oops */
fclose(in);
fclose(out);
elog(ERROR, "cannot write at block %u of \"%s\": %s",
blknum, to_path, strerror(errno_tmp));
}
/* update CRC */
COMP_CRC32C(crc, &header, sizeof(header));
COMP_CRC32C(crc, page.data, header.hole_offset);
COMP_CRC32C(crc, page.data + upper_offset, upper_length);
file->write_size += sizeof(header) + read_len - header.hole_length;
}
}
else
{
datapagemap_iterator_t *iter;
iter = datapagemap_iterate(&file->pagemap);
while (datapagemap_next(iter, &blknum))
{
XLogRecPtr page_lsn;
int upper_offset;
int upper_length;
int ret;
offset = blknum * BLCKSZ;
if (offset > 0)
{
ret = fseek(in, offset, SEEK_SET);
if (ret != 0)
elog(ERROR,
"Can't seek in file offset: %llu ret:%i\n",
(long long unsigned int) offset, ret);
}
read_len = fread(&page, 1, sizeof(page), in);
header.block = blknum;
/*
* If an invalid data page was found, fallback to simple copy to ensure
* all pages in the file don't have BackupPageHeader.
*/
if (!parse_page(&page, &page_lsn,
&header.hole_offset, &header.hole_length))
{
elog(LOG, "%s fall back to simple copy", file->path);
fclose(in);
fclose(out);
file->is_datafile = false;
return copy_file(from_root, to_root, file);
}
file->read_size += read_len;
/* if the page has not been modified since last backup, skip it */
if (lsn && !XLogRecPtrIsInvalid(page_lsn) && page_lsn < *lsn)
continue;
upper_offset = header.hole_offset + header.hole_length;
upper_length = BLCKSZ - upper_offset;
/* write data page excluding hole */
if (fwrite(&header, 1, sizeof(header), out) != sizeof(header) ||
fwrite(page.data, 1, header.hole_offset, out) != header.hole_offset ||
fwrite(page.data + upper_offset, 1, upper_length, out) != upper_length)
{
int errno_tmp = errno;
/* oops */
fclose(in);
fclose(out);
elog(ERROR, "cannot write at block %u of \"%s\": %s",
blknum, to_path, strerror(errno_tmp));
}
/* update CRC */
COMP_CRC32C(crc, &header, sizeof(header));
COMP_CRC32C(crc, page.data, header.hole_offset);
COMP_CRC32C(crc, page.data + upper_offset, upper_length);
file->write_size += sizeof(header) + read_len - header.hole_length;
}
pg_free(iter);
}
/*
* update file permission
* FIXME: Should set permission on open?
*/
if (!check && chmod(to_path, FILE_PERMISSION) == -1)
{
int errno_tmp = errno;
fclose(in);
fclose(out);
elog(ERROR, "cannot change mode of \"%s\": %s", file->path,
strerror(errno_tmp));
}
fclose(in);
fclose(out);
/* finish CRC calculation and store into pgFile */
FIN_CRC32C(crc);
file->crc = crc;
/* Treat empty file as not-datafile */
if (file->read_size == 0)
file->is_datafile = false;
/* We do not backup if all pages skipped. */
if (file->write_size == 0 && file->read_size > 0)
{
if (remove(to_path) == -1)
elog(ERROR, "cannot remove file \"%s\": %s", to_path,
strerror(errno));
return false;
}
/* remove $BACKUP_PATH/tmp created during check */
if (check)
remove(to_path);
return true;
}