/*
* __wt_log_get_active_files --
* Retrieve the list of active log files (those that are not candidates
* for archiving).
*/
int
__wt_log_get_active_files(
WT_SESSION_IMPL *session, char ***filesp, u_int *countp)
{
WT_DECL_RET;
WT_LOG *log;
char **files;
uint32_t id;
u_int count, i;
id = 0;
log = S2C(session)->log;
WT_RET(__wt_log_get_files(session, &files, &count));
/* Filter out any files that are below the checkpoint LSN. */
for (i = 0; i < count; ) {
WT_ERR(__wt_log_extract_lognum(session, files[i], &id));
if (id < log->ckpt_lsn.file) {
__wt_free(session, files[i]);
files[i] = files[count - 1];
files[--count] = NULL;
} else
i++;
}
*filesp = files;
*countp = count;
if (0) {
err: __wt_log_files_free(session, files, count);
}
return (ret);
}
/*
* __log_truncate --
* Truncate the log to the given LSN. If this_log is set, it will only
* truncate the log file indicated in the given LSN. If not set,
* it will truncate between the given LSN and the trunc_lsn. That is,
* since we pre-allocate log files, it will free that space and allow the
* log to be traversed. We use the trunc_lsn because logging has already
* opened the new/next log file before recovery ran. This function assumes
* we are in recovery or other dedicated time and not during live running.
*/
static int
__log_truncate(WT_SESSION_IMPL *session, WT_LSN *lsn, uint32_t this_log)
{
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
WT_FH *log_fh, *tmp_fh;
WT_LOG *log;
uint32_t lognum;
u_int i, logcount;
char **logfiles;
conn = S2C(session);
log = conn->log;
log_fh = NULL;
logcount = 0;
logfiles = NULL;
/*
* Truncate the log file to the given LSN.
*/
WT_ERR(__log_openfile(session, 0, &log_fh, lsn->file));
WT_ERR(__wt_ftruncate(session, log_fh, lsn->offset));
tmp_fh = log_fh;
log_fh = NULL;
WT_ERR(__wt_close(session, tmp_fh));
/*
* If we just want to truncate the current log, return and skip
* looking for intervening logs.
*/
if (this_log)
goto err;
WT_ERR(__wt_log_get_files(session, &logfiles, &logcount));
for (i = 0; i < logcount; i++) {
WT_ERR(__wt_log_extract_lognum(session, logfiles[i], &lognum));
if (lognum > lsn->file && lognum < log->trunc_lsn.file) {
WT_ERR(__log_openfile(session, 0, &log_fh, lognum));
/*
* If there are intervening files pre-allocated,
* truncate them to the end of the log file header.
*/
WT_ERR(__wt_ftruncate(session,
log_fh, LOG_FIRST_RECORD));
tmp_fh = log_fh;
log_fh = NULL;
WT_ERR(__wt_close(session, tmp_fh));
}
}
err: if (log_fh != NULL)
WT_TRET(__wt_close(session, log_fh));
if (logfiles != NULL)
__wt_log_files_free(session, logfiles, logcount);
return (ret);
}
/*
* __wt_log_open --
* Open the appropriate log file for the connection. The purpose is
* to find the last log file that exists, open it and set our initial
* LSNs to the end of that file. If none exist, call __wt_log_newfile
* to create it.
*/
int
__wt_log_open(WT_SESSION_IMPL *session)
{
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
WT_LOG *log;
uint32_t firstlog, lastlog, lognum;
u_int i, logcount;
char **logfiles;
conn = S2C(session);
log = conn->log;
lastlog = 0;
firstlog = UINT32_MAX;
WT_RET(__wt_log_get_files(session, &logfiles, &logcount));
for (i = 0; i < logcount; i++) {
WT_ERR(__wt_log_extract_lognum(session, logfiles[i], &lognum));
lastlog = WT_MAX(lastlog, lognum);
firstlog = WT_MIN(firstlog, lognum);
}
log->fileid = lastlog;
WT_ERR(__wt_verbose(session, WT_VERB_LOG,
"log_open: first log %d last log %d", firstlog, lastlog));
log->first_lsn.file = firstlog;
log->first_lsn.offset = 0;
/*
* Start logging at the beginning of the next log file, no matter
* where the previous log file ends.
*/
WT_ERR(__wt_log_newfile(session, 1));
/*
* If there were log files, run recovery.
* XXX belongs at a higher level than this.
*/
if (logcount > 0) {
log->trunc_lsn = log->alloc_lsn;
WT_ERR(__wt_txn_recover(session));
}
err: __wt_log_files_free(session, logfiles, logcount);
return (ret);
}
/*
* __backup_log_append --
* Append log files needed for backup.
*/
static int
__backup_log_append(WT_SESSION_IMPL *session, WT_CURSOR_BACKUP *cb, int active)
{
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
u_int i, logcount;
char **logfiles;
conn = S2C(session);
logfiles = NULL;
logcount = 0;
ret = 0;
if (conn->log) {
WT_ERR(__wt_log_get_all_files(
session, &logfiles, &logcount, &cb->maxid, active));
for (i = 0; i < logcount; i++)
WT_ERR(__backup_list_append(session, cb, logfiles[i]));
}
err: if (logfiles != NULL)
__wt_log_files_free(session, logfiles, logcount);
return (ret);
}
/*
* __log_archive_once --
* Perform one iteration of log archiving. Must be called with the
* log archive lock held.
*/
static int
__log_archive_once(WT_SESSION_IMPL *session, uint32_t backup_file)
{
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
WT_LOG *log;
uint32_t lognum, min_lognum;
u_int i, locked, logcount;
char **logfiles;
conn = S2C(session);
log = conn->log;
logcount = 0;
logfiles = NULL;
/*
* If we're coming from a backup cursor we want the smaller of
* the last full log file copied in backup or the checkpoint LSN.
* Otherwise we want the minimum of the last log file written to
* disk and the checkpoint LSN.
*/
if (backup_file != 0)
min_lognum = WT_MIN(log->ckpt_lsn.file, backup_file);
else
min_lognum = WT_MIN(log->ckpt_lsn.file, log->sync_lsn.file);
WT_RET(__wt_verbose(session, WT_VERB_LOG,
"log_archive: archive to log number %" PRIu32, min_lognum));
/*
* Main archive code. Get the list of all log files and
* remove any earlier than the minimum log number.
*/
WT_RET(__wt_dirlist(session, conn->log_path,
WT_LOG_FILENAME, WT_DIRLIST_INCLUDE, &logfiles, &logcount));
/*
* We can only archive files if a hot backup is not in progress or
* if we are the backup.
*/
WT_RET(__wt_readlock(session, conn->hot_backup_lock));
locked = 1;
if (conn->hot_backup == 0 || backup_file != 0) {
for (i = 0; i < logcount; i++) {
WT_ERR(__wt_log_extract_lognum(
session, logfiles[i], &lognum));
if (lognum < min_lognum)
WT_ERR(__wt_log_remove(
session, WT_LOG_FILENAME, lognum));
}
}
WT_ERR(__wt_readunlock(session, conn->hot_backup_lock));
locked = 0;
__wt_log_files_free(session, logfiles, logcount);
logfiles = NULL;
logcount = 0;
/*
* Indicate what is our new earliest LSN. It is the start
* of the log file containing the last checkpoint.
*/
log->first_lsn.file = min_lognum;
log->first_lsn.offset = 0;
if (0)
err: __wt_err(session, ret, "log archive server error");
if (locked)
WT_TRET(__wt_readunlock(session, conn->hot_backup_lock));
if (logfiles != NULL)
__wt_log_files_free(session, logfiles, logcount);
return (ret);
}
/*
* __wt_log_scan --
* Scan the logs, calling a function on each record found.
*/
int
__wt_log_scan(WT_SESSION_IMPL *session, WT_LSN *lsnp, uint32_t flags,
int (*func)(WT_SESSION_IMPL *session,
WT_ITEM *record, WT_LSN *lsnp, void *cookie), void *cookie)
{
WT_CONNECTION_IMPL *conn;
WT_ITEM buf;
WT_DECL_RET;
WT_FH *log_fh;
WT_LOG *log;
WT_LOG_RECORD *logrec;
WT_LSN end_lsn, rd_lsn, start_lsn;
off_t log_size;
uint32_t allocsize, cksum, firstlog, lastlog, lognum, rdup_len, reclen;
u_int i, logcount;
int eol;
char **logfiles;
conn = S2C(session);
log = conn->log;
log_fh = NULL;
logcount = 0;
logfiles = NULL;
eol = 0;
WT_CLEAR(buf);
/*
* If the caller did not give us a callback function there is nothing
* to do.
*/
if (func == NULL)
return (0);
if (LF_ISSET(WT_LOGSCAN_RECOVER))
WT_RET(__wt_verbose(session, WT_VERB_LOG,
"__wt_log_scan truncating to %u/%" PRIuMAX,
log->trunc_lsn.file, (uintmax_t)log->trunc_lsn.offset));
if (log != NULL) {
allocsize = log->allocsize;
if (lsnp == NULL) {
if (LF_ISSET(WT_LOGSCAN_FIRST))
start_lsn = log->first_lsn;
else if (LF_ISSET(WT_LOGSCAN_FROM_CKP))
start_lsn = log->ckpt_lsn;
else
return (WT_ERROR); /* Illegal usage */
} else {
if (LF_ISSET(WT_LOGSCAN_FIRST|WT_LOGSCAN_FROM_CKP))
WT_RET_MSG(session, WT_ERROR,
"choose either a start LSN or a start flag");
/* Offsets must be on allocation boundaries. */
if (lsnp->offset % allocsize != 0 ||
lsnp->file > log->fileid)
return (WT_NOTFOUND);
/*
* Log cursors may not know the starting LSN. If an
* LSN pointer is passed in, but it is the INIT_LSN,
* start from the first_lsn.
*/
start_lsn = *lsnp;
if (IS_INIT_LSN(&start_lsn))
start_lsn = log->first_lsn;
}
end_lsn = log->alloc_lsn;
} else {
/*
* If logging is not configured, we can still print out the log
* if log files exist. We just need to set the LSNs from what
* is in the files versus what is in the live connection.
*/
/*
* Set allocsize to the minimum alignment it could be. Larger
* records and larger allocation boundaries should always be
* a multiple of this.
*/
allocsize = LOG_ALIGN;
lastlog = 0;
firstlog = UINT32_MAX;
WT_RET(__wt_log_get_files(session, &logfiles, &logcount));
if (logcount == 0)
/*
* Return it is not supported if none don't exist.
*/
return (ENOTSUP);
for (i = 0; i < logcount; i++) {
WT_ERR(__wt_log_extract_lognum(session, logfiles[i],
&lognum));
lastlog = WT_MAX(lastlog, lognum);
firstlog = WT_MIN(firstlog, lognum);
}
start_lsn.file = firstlog;
end_lsn.file = lastlog;
start_lsn.offset = end_lsn.offset = 0;
__wt_log_files_free(session, logfiles, logcount);
logfiles = NULL;
}
WT_ERR(__log_openfile(session, 0, &log_fh, start_lsn.file));
WT_ERR(__log_filesize(session, log_fh, &log_size));
rd_lsn = start_lsn;
WT_ERR(__wt_buf_initsize(session, &buf, LOG_ALIGN));
for (;;) {
if (rd_lsn.offset + allocsize > log_size) {
advance:
/*
* If we read the last record, go to the next file.
*/
WT_ERR(__wt_close(session, log_fh));
log_fh = NULL;
eol = 1;
/*
* Truncate this log file before we move to the next.
*/
if (LF_ISSET(WT_LOGSCAN_RECOVER))
WT_ERR(__log_truncate(session, &rd_lsn, 1));
rd_lsn.file++;
rd_lsn.offset = 0;
/*
* Avoid an error message when we reach end of log
* by checking here.
*/
if (rd_lsn.file > end_lsn.file)
break;
WT_ERR(__log_openfile(
session, 0, &log_fh, rd_lsn.file));
WT_ERR(__log_filesize(session, log_fh, &log_size));
continue;
}
/*
* Read the minimum allocation size a record could be.
*/
WT_ASSERT(session, buf.memsize >= allocsize);
WT_ERR(__wt_read(session,
log_fh, rd_lsn.offset, (size_t)allocsize, buf.mem));
/*
* First 8 bytes is the real record length. See if we
* need to read more than the allocation size. We expect
* that we rarely will have to read more. Most log records
* will be fairly small.
*/
reclen = *(uint32_t *)buf.mem;
/*
* Log files are pre-allocated. We never expect a zero length
* unless we've reached the end of the log. The log can be
* written out of order, so when recovery finds the end of
* the log, truncate the file and remove any later log files
* that may exist.
*/
if (reclen == 0) {
/* This LSN is the end. */
break;
}
rdup_len = __wt_rduppo2(reclen, allocsize);
if (reclen > allocsize) {
/*
* The log file end could be the middle of this
* log record.
*/
if (rd_lsn.offset + rdup_len > log_size)
goto advance;
/*
* We need to round up and read in the full padded
* record, especially for direct I/O.
*/
WT_ERR(__wt_buf_grow(session, &buf, rdup_len));
WT_ERR(__wt_read(session,
log_fh, rd_lsn.offset, (size_t)rdup_len, buf.mem));
WT_STAT_FAST_CONN_INCR(session, log_scan_rereads);
}
/*
* We read in the record, verify checksum.
*/
buf.size = reclen;
logrec = (WT_LOG_RECORD *)buf.mem;
cksum = logrec->checksum;
logrec->checksum = 0;
logrec->checksum = __wt_cksum(logrec, logrec->len);
if (logrec->checksum != cksum) {
/*
* A checksum mismatch means we have reached the end of
* the useful part of the log. This should be found on
* the first pass through recovery. In the second pass
* where we truncate the log, this is where it should
* end.
*/
if (log != NULL)
log->trunc_lsn = rd_lsn;
break;
}
/*
* We have a valid log record. If it is not the log file
* header, invoke the callback.
*/
WT_STAT_FAST_CONN_INCR(session, log_scan_records);
if (rd_lsn.offset != 0) {
WT_ERR((*func)(session, &buf, &rd_lsn, cookie));
if (LF_ISSET(WT_LOGSCAN_ONE))
break;
}
rd_lsn.offset += (off_t)rdup_len;
}
/* Truncate if we're in recovery. */
if (LF_ISSET(WT_LOGSCAN_RECOVER) &&
LOG_CMP(&rd_lsn, &log->trunc_lsn) < 0)
WT_ERR(__log_truncate(session, &rd_lsn, 0));
err: WT_STAT_FAST_CONN_INCR(session, log_scans);
if (logfiles != NULL)
__wt_log_files_free(session, logfiles, logcount);
__wt_buf_free(session, &buf);
/*
* If the caller wants one record and it is at the end of log,
* return WT_NOTFOUND.
*/
if (LF_ISSET(WT_LOGSCAN_ONE) && eol && ret == 0)
ret = WT_NOTFOUND;
if (ret == ENOENT)
ret = 0;
if (log_fh != NULL)
WT_TRET(__wt_close(session, log_fh));
return (ret);
}
/*
* __backup_start --
* Start a backup.
*/
static int
__backup_start(
WT_SESSION_IMPL *session, WT_CURSOR_BACKUP *cb, const char *cfg[])
{
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
u_int i, logcount;
int target_list;
char **logfiles;
conn = S2C(session);
cb->next = 0;
cb->list = NULL;
logfiles = NULL;
logcount = 0;
/*
* Single thread hot backups: we're holding the schema lock, so we
* know we'll serialize with other attempts to start a hot backup.
*/
if (conn->hot_backup)
WT_RET_MSG(
session, EINVAL, "there is already a backup cursor open");
/*
* The hot backup copy is done outside of WiredTiger, which means file
* blocks can't be freed and re-allocated until the backup completes.
* The checkpoint code checks the backup flag, and if a backup cursor
* is open checkpoints aren't discarded. We release the lock as soon
* as we've set the flag, we don't want to block checkpoints, we just
* want to make sure no checkpoints are deleted. The checkpoint code
* holds the lock until it's finished the checkpoint, otherwise we
* could start a hot backup that would race with an already-started
* checkpoint.
*/
__wt_spin_lock(session, &conn->hot_backup_lock);
conn->hot_backup = 1;
__wt_spin_unlock(session, &conn->hot_backup_lock);
/* Create the hot backup file. */
WT_ERR(__backup_file_create(session, cb));
/* Add log files if logging is enabled. */
/*
* If a list of targets was specified, work our way through them.
* Else, generate a list of all database objects.
*
* Include log files if doing a full backup, and copy them before
* copying data files to avoid rolling the metadata forward across
* a checkpoint that completes during the backup.
*/
target_list = 0;
WT_ERR(__backup_uri(session, cb, cfg, &target_list));
if (!target_list) {
if (conn->log) {
WT_ERR(__wt_log_get_active_files(
session, &logfiles, &logcount));
for (i = 0; i < logcount; i++)
WT_ERR(__backup_list_append(
session, cb, logfiles[i]));
}
WT_ERR(__backup_all(session, cb));
}
/* Add the hot backup and single-threading file to the list. */
WT_ERR(__backup_list_append(session, cb, WT_METADATA_BACKUP));
WT_ERR(__backup_list_append(session, cb, WT_SINGLETHREAD));
err: /* Close the hot backup file. */
if (cb->bfp != NULL) {
WT_TRET(fclose(cb->bfp) == 0 ? 0 : __wt_errno());
cb->bfp = NULL;
}
if (logfiles != NULL)
__wt_log_files_free(session, logfiles, logcount);
if (ret != 0) {
WT_TRET(__backup_cleanup_handles(session, cb));
WT_TRET(__backup_stop(session));
}
return (ret);
}
