/*
* __rename_file --
* WT_SESSION::rename for a file.
*/
static int
__rename_file(
WT_SESSION_IMPL *session, const char *uri, const char *newuri)
{
WT_DECL_RET;
bool exist;
const char *filename, *newfile;
char *newvalue, *oldvalue;
newvalue = oldvalue = NULL;
filename = uri;
newfile = newuri;
if (!WT_PREFIX_SKIP(filename, "file:") ||
!WT_PREFIX_SKIP(newfile, "file:"))
return (EINVAL);
/* Close any btree handles in the file. */
WT_WITH_HANDLE_LIST_LOCK(session,
ret = __wt_conn_dhandle_close_all(session, uri, false));
WT_ERR(ret);
/*
* First, check if the file being renamed exists in the system. Doing
* this check first matches the table rename behavior because we return
* WT_NOTFOUND when the renamed file doesn't exist (subsequently mapped
* to ENOENT by the session layer).
*/
WT_ERR(__wt_metadata_search(session, uri, &oldvalue));
/*
* Check to see if the proposed name is already in use, in either the
* metadata or the filesystem.
*/
switch (ret = __wt_metadata_search(session, newuri, &newvalue)) {
case 0:
WT_ERR_MSG(session, EEXIST, "%s", newuri);
/* NOTREACHED */
case WT_NOTFOUND:
break;
default:
WT_ERR(ret);
}
WT_ERR(__wt_fs_exist(session, newfile, &exist));
if (exist)
WT_ERR_MSG(session, EEXIST, "%s", newfile);
/* Replace the old file entries with new file entries. */
WT_ERR(__wt_metadata_remove(session, uri));
WT_ERR(__wt_metadata_insert(session, newuri, oldvalue));
/* Rename the underlying file. */
WT_ERR(__wt_fs_rename(session, filename, newfile, false));
if (WT_META_TRACKING(session))
WT_ERR(__wt_meta_track_fileop(session, uri, newuri));
err: __wt_free(session, newvalue);
__wt_free(session, oldvalue);
return (ret);
}
/*
* __meta_track_unroll --
* Undo the changes in a metadata tracking record.
*/
static int
__meta_track_unroll(WT_SESSION_IMPL *session, WT_META_TRACK *trk)
{
WT_DECL_RET;
switch (trk->op) {
case WT_ST_EMPTY: /* Unused slot */
break;
case WT_ST_CHECKPOINT: /* Checkpoint, see above */
break;
case WT_ST_DROP_COMMIT:
break;
case WT_ST_LOCK: /* Handle lock, see above */
if (trk->created)
F_SET(trk->dhandle, WT_DHANDLE_DISCARD);
WT_WITH_DHANDLE(session, trk->dhandle,
ret = __wt_session_release_btree(session));
break;
case WT_ST_FILEOP: /* File operation */
/*
* For renames, both a and b are set.
* For creates, a is NULL.
* For removes, b is NULL.
*/
if (trk->a != NULL && trk->b != NULL &&
(ret = __wt_fs_rename(session,
trk->b + strlen("file:"), trk->a + strlen("file:"),
true)) != 0)
__wt_err(session, ret,
"metadata unroll rename %s to %s", trk->b, trk->a);
if (trk->a == NULL &&
(ret = __wt_fs_remove(session,
trk->b + strlen("file:"), false)) != 0)
__wt_err(session, ret,
"metadata unroll create %s", trk->b);
/*
* We can't undo removes yet: that would imply
* some kind of temporary rename and remove in
* roll forward.
*/
break;
case WT_ST_REMOVE: /* Remove trk.a */
if ((ret = __wt_metadata_remove(session, trk->a)) != 0)
__wt_err(session, ret,
"metadata unroll remove: %s", trk->a);
break;
case WT_ST_SET: /* Set trk.a to trk.b */
if ((ret = __wt_metadata_update(session, trk->a, trk->b)) != 0)
__wt_err(session, ret,
"metadata unroll update %s to %s", trk->a, trk->b);
break;
}
__meta_track_clear(session, trk);
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);
}
