/*
* __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);
}
/*
* __wt_remove_if_exists --
* Remove a file if it exists.
*/
int
__wt_remove_if_exists(WT_SESSION_IMPL *session, const char *name, bool durable)
{
bool exist;
WT_RET(__wt_fs_exist(session, name, &exist));
if (exist)
WT_RET(__wt_fs_remove(session, name, durable));
return (0);
}
/*
* __wt_turtle_read --
* Read the turtle file.
*/
int
__wt_turtle_read(WT_SESSION_IMPL *session, const char *key, char **valuep)
{
WT_DECL_ITEM(buf);
WT_DECL_RET;
WT_FSTREAM *fs;
bool exist, match;
*valuep = NULL;
/*
* Open the turtle file; there's one case where we won't find the turtle
* file, yet still succeed. We create the metadata file before creating
* the turtle file, and that means returning the default configuration
* string for the metadata file.
*/
WT_RET(__wt_fs_exist(session, WT_METADATA_TURTLE, &exist));
if (!exist)
return (strcmp(key, WT_METAFILE_URI) == 0 ?
__metadata_config(session, valuep) : WT_NOTFOUND);
WT_RET(__wt_fopen(session, WT_METADATA_TURTLE, 0, WT_STREAM_READ, &fs));
/* Search for the key. */
WT_ERR(__wt_scr_alloc(session, 512, &buf));
for (match = false;;) {
WT_ERR(__wt_getline(session, fs, buf));
if (buf->size == 0)
WT_ERR(WT_NOTFOUND);
if (strcmp(key, buf->data) == 0)
match = true;
/* Key matched: read the subsequent line for the value. */
WT_ERR(__wt_getline(session, fs, buf));
if (buf->size == 0)
WT_ERR(__wt_illegal_value(session, WT_METADATA_TURTLE));
if (match)
break;
}
/* Copy the value for the caller. */
WT_ERR(__wt_strdup(session, buf->data, valuep));
err: WT_TRET(__wt_fclose(session, &fs));
__wt_scr_free(session, &buf);
if (ret != 0)
__wt_free(session, *valuep);
return (ret);
}
/*
* __metadata_load_bulk --
* Create any bulk-loaded file stubs.
*/
static int
__metadata_load_bulk(WT_SESSION_IMPL *session)
{
WT_CURSOR *cursor;
WT_DECL_RET;
uint32_t allocsize;
bool exist;
const char *filecfg[] = {
WT_CONFIG_BASE(session, file_meta), NULL, NULL };
const char *key, *value;
/*
* If a file was being bulk-loaded during the hot backup, it will appear
* in the metadata file, but the file won't exist. Create on demand.
*/
WT_RET(__wt_metadata_cursor(session, &cursor));
while ((ret = cursor->next(cursor)) == 0) {
WT_ERR(cursor->get_key(cursor, &key));
if (!WT_PREFIX_SKIP(key, "file:"))
continue;
/* If the file exists, it's all good. */
WT_ERR(__wt_fs_exist(session, key, &exist));
if (exist)
continue;
/*
* If the file doesn't exist, assume it's a bulk-loaded file;
* retrieve the allocation size and re-create the file.
*/
WT_ERR(cursor->get_value(cursor, &value));
filecfg[1] = value;
WT_ERR(__wt_direct_io_size_check(
session, filecfg, "allocation_size", &allocsize));
WT_ERR(__wt_block_manager_create(session, key, allocsize));
}
WT_ERR_NOTFOUND_OK(ret);
err: WT_TRET(__wt_metadata_cursor_release(session, &cursor));
return (ret);
}
/*
* __metadata_load_hot_backup --
* Load the contents of any hot backup file.
*/
static int
__metadata_load_hot_backup(WT_SESSION_IMPL *session)
{
WT_DECL_ITEM(key);
WT_DECL_ITEM(value);
WT_DECL_RET;
WT_FSTREAM *fs;
bool exist;
/* Look for a hot backup file: if we find it, load it. */
WT_RET(__wt_fs_exist(session, WT_METADATA_BACKUP, &exist));
if (!exist)
return (0);
WT_RET(__wt_fopen(session,
WT_METADATA_BACKUP, 0, WT_STREAM_READ, &fs));
/* Read line pairs and load them into the metadata file. */
WT_ERR(__wt_scr_alloc(session, 512, &key));
WT_ERR(__wt_scr_alloc(session, 512, &value));
for (;;) {
WT_ERR(__wt_getline(session, fs, key));
if (key->size == 0)
break;
WT_ERR(__wt_getline(session, fs, value));
if (value->size == 0)
WT_ERR(__wt_illegal_value(session, WT_METADATA_BACKUP));
WT_ERR(__wt_metadata_update(session, key->data, value->data));
}
F_SET(S2C(session), WT_CONN_WAS_BACKUP);
err: WT_TRET(__wt_fclose(session, &fs));
__wt_scr_free(session, &key);
__wt_scr_free(session, &value);
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);
}
/*
* __wt_turtle_init --
* Check the turtle file and create if necessary.
*/
int
__wt_turtle_init(WT_SESSION_IMPL *session)
{
WT_DECL_RET;
bool exist_backup, exist_incr, exist_isrc, exist_turtle, load;
char *metaconf;
metaconf = NULL;
load = false;
/*
* Discard any turtle setup file left-over from previous runs. This
* doesn't matter for correctness, it's just cleaning up random files.
*/
WT_RET(__wt_remove_if_exists(session, WT_METADATA_TURTLE_SET, false));
/*
* We could die after creating the turtle file and before creating the
* metadata file, or worse, the metadata file might be in some random
* state. Make sure that doesn't happen: if we don't find the turtle
* file, first create the metadata file, load any hot backup, and then
* create the turtle file. No matter what happens, if metadata file
* creation doesn't fully complete, we won't have a turtle file and we
* will repeat the process until we succeed.
*
* Incremental backups can occur only if recovery is run and it becomes
* live. So, if there is a turtle file and an incremental backup file,
* that is an error. Otherwise, if there's already a turtle file, we're
* done.
*/
WT_RET(__wt_fs_exist(session, WT_INCREMENTAL_BACKUP, &exist_incr));
WT_RET(__wt_fs_exist(session, WT_INCREMENTAL_SRC, &exist_isrc));
WT_RET(__wt_fs_exist(session, WT_METADATA_BACKUP, &exist_backup));
WT_RET(__wt_fs_exist(session, WT_METADATA_TURTLE, &exist_turtle));
if (exist_turtle) {
/*
* We need to detect the difference between a source database
* that may have crashed with an incremental backup file
* and a destination database that incorrectly ran recovery.
*/
if (exist_incr && !exist_isrc)
WT_RET_MSG(session, EINVAL,
"Incremental backup after running recovery "
"is not allowed");
/*
* If we have a backup file and metadata and turtle files,
* we want to recreate the metadata from the backup.
*/
if (exist_backup) {
WT_RET(__wt_msg(session,
"Both %s and %s exist; recreating metadata from "
"backup",
WT_METADATA_TURTLE, WT_METADATA_BACKUP));
WT_RET(
__wt_remove_if_exists(session, WT_METAFILE, false));
WT_RET(__wt_remove_if_exists(
session, WT_METADATA_TURTLE, false));
load = true;
}
} else
load = true;
if (load) {
if (exist_incr)
F_SET(S2C(session), WT_CONN_WAS_BACKUP);
/* Create the metadata file. */
WT_RET(__metadata_init(session));
/* Load any hot-backup information. */
WT_RET(__metadata_load_hot_backup(session));
/* Create any bulk-loaded file stubs. */
WT_RET(__metadata_load_bulk(session));
/* Create the turtle file. */
WT_RET(__metadata_config(session, &metaconf));
WT_WITH_TURTLE_LOCK(session, ret,
ret = __wt_turtle_update(
session, WT_METAFILE_URI, metaconf));
WT_ERR(ret);
}
/* Remove the backup files, we'll never read them again. */
WT_ERR(__wt_backup_file_remove(session));
err: __wt_free(session, metaconf);
return (ret);
}
