/*
* __wt_backup_list_uri_append --
* Append a new file name to the list, allocate space as necessary.
* Called via the schema_worker function.
*/
int
__wt_backup_list_uri_append(
WT_SESSION_IMPL *session, const char *name, int *skip)
{
WT_CURSOR_BACKUP *cb;
char *value;
cb = session->bkp_cursor;
WT_UNUSED(skip);
if (WT_PREFIX_MATCH(name, "log:")) {
WT_RET(__backup_log_append(session, cb, 0));
return (0);
}
/* Add the metadata entry to the backup file. */
WT_RET(__wt_metadata_search(session, name, &value));
WT_RET_TEST(
(fprintf(cb->bfp, "%s\n%s\n", name, value) < 0), __wt_errno());
__wt_free(session, value);
/* Add file type objects to the list of files to be copied. */
if (WT_PREFIX_MATCH(name, "file:"))
WT_RET(__backup_list_append(session, cb, name));
return (0);
}
/*
* __backup_list_uri_append --
* Append a new file name to the list, allocate space as necessary.
* Called via the schema_worker function.
*/
static int
__backup_list_uri_append(
WT_SESSION_IMPL *session, const char *name, bool *skip)
{
WT_CURSOR_BACKUP *cb;
char *value;
cb = session->bkp_cursor;
WT_UNUSED(skip);
/*
* While reading the metadata file, check there are no data sources
* that can't support hot backup. This checks for a data source that's
* non-standard, which can't be backed up, but is also sanity checking:
* if there's an entry backed by anything other than a file or lsm
* entry, we're confused.
*/
if (WT_PREFIX_MATCH(name, "log:")) {
WT_RET(__backup_log_append(session, cb, false));
return (0);
}
if (!WT_PREFIX_MATCH(name, "file:") &&
!WT_PREFIX_MATCH(name, "colgroup:") &&
!WT_PREFIX_MATCH(name, "index:") &&
!WT_PREFIX_MATCH(name, "lsm:") &&
!WT_PREFIX_MATCH(name, "table:"))
WT_RET_MSG(session, ENOTSUP,
"hot backup is not supported for objects of type %s",
name);
/* Ignore the lookaside table. */
if (strcmp(name, WT_LAS_URI) == 0)
return (0);
/* Add the metadata entry to the backup file. */
WT_RET(__wt_metadata_search(session, name, &value));
WT_RET(__wt_fprintf(cb->bfp, "%s\n%s\n", name, value));
__wt_free(session, value);
/* Add file type objects to the list of files to be copied. */
if (WT_PREFIX_MATCH(name, "file:"))
WT_RET(__backup_list_append(session, cb, name));
return (0);
}
/*
* __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;
int exist, log_only, target_list;
conn = S2C(session);
cb->next = 0;
cb->list = NULL;
/*
* 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, 0));
/* 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, &log_only));
if (!target_list) {
WT_ERR(__backup_log_append(session, cb, 1));
WT_ERR(__backup_all(session, cb));
}
/* Add the hot backup and standard WiredTiger files to the list. */
if (log_only) {
/*
* Close any hot backup file.
* We're about to open the incremental backup file.
*/
if (cb->bfp != NULL) {
WT_TRET(fclose(cb->bfp) == 0 ? 0 : __wt_errno());
cb->bfp = NULL;
}
WT_ERR(__backup_file_create(session, cb, log_only));
WT_ERR(__backup_list_append(
session, cb, WT_INCREMENTAL_BACKUP));
} else {
WT_ERR(__backup_list_append(
session, cb, WT_METADATA_BACKUP));
WT_ERR(__wt_exist(session, WT_BASECONFIG, &exist));
if (exist)
WT_ERR(__backup_list_append(
session, cb, WT_BASECONFIG));
WT_ERR(__wt_exist(session, WT_USERCONFIG, &exist));
if (exist)
WT_ERR(__backup_list_append(
session, cb, WT_USERCONFIG));
WT_ERR(__backup_list_append(session, cb, WT_WIREDTIGER));
}
err: /* Close the hot backup file. */
if (cb->bfp != NULL) {
WT_TRET(fclose(cb->bfp) == 0 ? 0 : __wt_errno());
cb->bfp = NULL;
}
if (ret != 0) {
WT_TRET(__backup_cleanup_handles(session, cb));
WT_TRET(__backup_stop(session));
}
return (ret);
}
/*
* __backup_uri --
* Backup a list of objects.
*/
static int
__backup_uri(WT_SESSION_IMPL *session,
const char *cfg[], bool *foundp, bool *log_only)
{
WT_CONFIG targetconf;
WT_CONFIG_ITEM cval, k, v;
WT_DECL_ITEM(tmp);
WT_DECL_RET;
bool target_list;
const char *uri;
*foundp = *log_only = false;
/*
* If we find a non-empty target configuration string, we have a job,
* otherwise it's not our problem.
*/
WT_RET(__wt_config_gets(session, cfg, "target", &cval));
__wt_config_subinit(session, &targetconf, &cval);
for (target_list = false;
(ret = __wt_config_next(&targetconf, &k, &v)) == 0;
target_list = true) {
/* If it is our first time through, allocate. */
if (!target_list) {
*foundp = true;
WT_ERR(__wt_scr_alloc(session, 512, &tmp));
}
WT_ERR(__wt_buf_fmt(session, tmp, "%.*s", (int)k.len, k.str));
uri = tmp->data;
if (v.len != 0)
WT_ERR_MSG(session, EINVAL,
"%s: invalid backup target: URIs may need quoting",
uri);
/*
* Handle log targets. We do not need to go through the schema
* worker, just call the function to append them. Set log_only
* only if it is our only URI target.
*/
if (WT_PREFIX_MATCH(uri, "log:")) {
/*
* Log archive cannot mix with incremental backup, don't
* let that happen.
*/
if (FLD_ISSET(
S2C(session)->log_flags, WT_CONN_LOG_ARCHIVE))
WT_ERR_MSG(session, EINVAL,
"incremental backup not possible when "
"automatic log archival configured");
*log_only = !target_list;
WT_ERR(__backup_log_append(
session, session->bkp_cursor, false));
} else {
*log_only = false;
WT_ERR(__wt_schema_worker(session,
uri, NULL, __backup_list_uri_append, cfg, 0));
}
}
WT_ERR_NOTFOUND_OK(ret);
err: __wt_scr_free(session, &tmp);
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;
WT_FSTREAM *srcfs;
const char *dest;
bool exist, log_only, target_list;
conn = S2C(session);
srcfs = NULL;
dest = NULL;
cb->next = 0;
cb->list = NULL;
cb->list_next = 0;
WT_RET(__wt_inmem_unsupported_op(session, "backup cursor"));
/*
* 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.
*
* We are holding the checkpoint and schema locks so schema operations
* will not see the backup file list until it is complete and valid.
*/
__wt_writelock(session, &conn->hot_backup_lock);
conn->hot_backup = true;
conn->hot_backup_list = NULL;
__wt_writeunlock(session, &conn->hot_backup_lock);
/* We're the lock holder, we own cleanup. */
F_SET(cb, WT_CURBACKUP_LOCKER);
/*
* Create a temporary backup file. This must be opened before
* generating the list of targets in backup_uri. This file will
* later be renamed to the correct name depending on whether or not
* we're doing an incremental backup. We need a temp file so that if
* we fail or crash while filling it, the existence of a partial file
* doesn't confuse restarting in the source database.
*/
WT_ERR(__wt_fopen(session, WT_BACKUP_TMP,
WT_FS_OPEN_CREATE, WT_STREAM_WRITE, &cb->bfs));
/*
* 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 = false;
WT_ERR(__backup_uri(session, cfg, &target_list, &log_only));
if (!target_list) {
WT_ERR(__backup_log_append(session, cb, true));
WT_ERR(__backup_all(session));
}
/* Add the hot backup and standard WiredTiger files to the list. */
if (log_only) {
/*
* We also open an incremental backup source file so that we
* can detect a crash with an incremental backup existing in
* the source directory versus an improper destination.
*/
dest = WT_INCREMENTAL_BACKUP;
WT_ERR(__wt_fopen(session, WT_INCREMENTAL_SRC,
WT_FS_OPEN_CREATE, WT_STREAM_WRITE, &srcfs));
WT_ERR(__backup_list_append(
session, cb, WT_INCREMENTAL_BACKUP));
} else {
dest = WT_METADATA_BACKUP;
WT_ERR(__backup_list_append(session, cb, WT_METADATA_BACKUP));
WT_ERR(__wt_fs_exist(session, WT_BASECONFIG, &exist));
if (exist)
WT_ERR(__backup_list_append(
session, cb, WT_BASECONFIG));
WT_ERR(__wt_fs_exist(session, WT_USERCONFIG, &exist));
if (exist)
WT_ERR(__backup_list_append(
session, cb, WT_USERCONFIG));
WT_ERR(__backup_list_append(session, cb, WT_WIREDTIGER));
}
err: /* Close the hot backup file. */
WT_TRET(__wt_fclose(session, &cb->bfs));
if (srcfs != NULL)
WT_TRET(__wt_fclose(session, &srcfs));
if (ret == 0) {
WT_ASSERT(session, dest != NULL);
WT_TRET(__wt_fs_rename(session, WT_BACKUP_TMP, dest, false));
__wt_writelock(session, &conn->hot_backup_lock);
conn->hot_backup_list = cb->list;
__wt_writeunlock(session, &conn->hot_backup_lock);
}
return (ret);
}
