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/*-
* Copyright (c) 2014-2015 MongoDB, Inc.
* Copyright (c) 2008-2014 WiredTiger, Inc.
* All rights reserved.
*
* See the file LICENSE for redistribution information.
*/
#include "wt_internal.h"
/* State maintained during recovery. */
typedef struct {
WT_SESSION_IMPL *session;
/* Files from the metadata, indexed by file ID. */
struct WT_RECOVERY_FILE {
const char *uri; /* File URI. */
WT_CURSOR *c; /* Cursor used for recovery. */
WT_LSN ckpt_lsn; /* File's checkpoint LSN. */
} *files;
size_t file_alloc; /* Allocated size of files array. */
u_int max_fileid; /* Maximum file ID seen. */
u_int nfiles; /* Number of files in the metadata. */
WT_LSN ckpt_lsn; /* Start LSN for main recovery loop. */
int missing; /* Were there missing files? */
int modified; /* Did recovery make any changes? */
int metadata_only; /*
* Set during the first recovery pass,
* when only the metadata is recovered.
*/
} WT_RECOVERY;
/*
* __recovery_cursor --
* Get a cursor for a recovery operation.
*/
static int
__recovery_cursor(WT_SESSION_IMPL *session, WT_RECOVERY *r,
WT_LSN *lsnp, u_int id, int duplicate, WT_CURSOR **cp)
{
WT_CURSOR *c;
const char *cfg[] = { WT_CONFIG_BASE(session, session_open_cursor),
"overwrite", NULL };
int metadata_op;
c = NULL;
/*
* Metadata operations have an id of 0. Match operations based
* on the id and the current pass of recovery for metadata.
*
* Only apply operations in the correct metadata phase, and if the LSN
* is more recent than the last checkpoint. If there is no entry for a
* file, assume it was dropped or missing after a hot backup.
*/
metadata_op = (id == WT_METAFILE_ID);
if (r->metadata_only != metadata_op)
;
else if (id >= r->nfiles || r->files[id].uri == NULL) {
/* If a file is missing, output a verbose message once. */
if (!r->missing)
WT_RET(__wt_verbose(session, WT_VERB_RECOVERY,
"No file found with ID %u (max %u)",
id, r->nfiles));
r->missing = 1;
} else if (LOG_CMP(lsnp, &r->files[id].ckpt_lsn) >= 0) {
/*
* We're going to apply the operation. Get the cursor, opening
* one if none is cached.
*/
if ((c = r->files[id].c) == NULL) {
WT_RET(__wt_open_cursor(
session, r->files[id].uri, NULL, cfg, &c));
r->files[id].c = c;
}
}
if (duplicate && c != NULL)
WT_RET(__wt_open_cursor(
session, r->files[id].uri, NULL, cfg, &c));
*cp = c;
return (0);
}
/*
* Helper to a cursor if this operation is to be applied during recovery.
*/
#define GET_RECOVERY_CURSOR(session, r, lsnp, fileid, cp) \
WT_ERR(__recovery_cursor( \
(session), (r), (lsnp), (fileid), 0, (cp))); \
WT_ERR(__wt_verbose((session), WT_VERB_RECOVERY, \
"%s op %d to file %d at LSN %u/%" PRIuMAX, \
(cursor == NULL) ? "Skipping" : "Applying", \
optype, fileid, lsnp->file, (uintmax_t)lsnp->offset)); \
if (cursor == NULL) \
break
/*
* __txn_op_apply --
* Apply a transactional operation during recovery.
*/
static int
__txn_op_apply(
WT_RECOVERY *r, WT_LSN *lsnp, const uint8_t **pp, const uint8_t *end)
{
WT_CURSOR *cursor, *start, *stop;
WT_DECL_RET;
WT_ITEM key, start_key, stop_key, value;
WT_SESSION_IMPL *session;
uint64_t recno, start_recno, stop_recno;
uint32_t fileid, mode, optype, opsize;
session = r->session;
cursor = NULL;
/* Peek at the size and the type. */
WT_ERR(__wt_logop_read(session, pp, end, &optype, &opsize));
end = *pp + opsize;
switch (optype) {
case WT_LOGOP_COL_PUT:
WT_ERR(__wt_logop_col_put_unpack(session, pp, end,
&fileid, &recno, &value));
GET_RECOVERY_CURSOR(session, r, lsnp, fileid, &cursor);
cursor->set_key(cursor, recno);
__wt_cursor_set_raw_value(cursor, &value);
WT_ERR(cursor->insert(cursor));
break;
case WT_LOGOP_COL_REMOVE:
WT_ERR(__wt_logop_col_remove_unpack(session, pp, end,
&fileid, &recno));
GET_RECOVERY_CURSOR(session, r, lsnp, fileid, &cursor);
cursor->set_key(cursor, recno);
WT_ERR(cursor->remove(cursor));
break;
case WT_LOGOP_COL_TRUNCATE:
WT_ERR(__wt_logop_col_truncate_unpack(session, pp, end,
&fileid, &start_recno, &stop_recno));
GET_RECOVERY_CURSOR(session, r, lsnp, fileid, &cursor);
/* Set up the cursors. */
if (start_recno == 0) {
start = NULL;
stop = cursor;
} else if (stop_recno == 0) {
start = cursor;
stop = NULL;
} else {
start = cursor;
WT_ERR(__recovery_cursor(
session, r, lsnp, fileid, 1, &stop));
}
/* Set the keys. */
if (start != NULL)
start->set_key(start, start_recno);
if (stop != NULL)
stop->set_key(stop, stop_recno);
WT_TRET(session->iface.truncate(&session->iface, NULL,
start, stop, NULL));
/* If we opened a duplicate cursor, close it now. */
if (stop != NULL && stop != cursor)
WT_TRET(stop->close(stop));
WT_ERR(ret);
break;
case WT_LOGOP_ROW_PUT:
WT_ERR(__wt_logop_row_put_unpack(session, pp, end,
&fileid, &key, &value));
GET_RECOVERY_CURSOR(session, r, lsnp, fileid, &cursor);
__wt_cursor_set_raw_key(cursor, &key);
__wt_cursor_set_raw_value(cursor, &value);
WT_ERR(cursor->insert(cursor));
break;
case WT_LOGOP_ROW_REMOVE:
WT_ERR(__wt_logop_row_remove_unpack(session, pp, end,
&fileid, &key));
GET_RECOVERY_CURSOR(session, r, lsnp, fileid, &cursor);
__wt_cursor_set_raw_key(cursor, &key);
WT_ERR(cursor->remove(cursor));
break;
case WT_LOGOP_ROW_TRUNCATE:
WT_ERR(__wt_logop_row_truncate_unpack(session, pp, end,
&fileid, &start_key, &stop_key, &mode));
GET_RECOVERY_CURSOR(session, r, lsnp, fileid, &cursor);
/* Set up the cursors. */
start = stop = NULL;
switch (mode) {
case TXN_TRUNC_ALL:
/* Both cursors stay NULL. */
break;
case TXN_TRUNC_BOTH:
start = cursor;
WT_ERR(__recovery_cursor(
session, r, lsnp, fileid, 1, &stop));
break;
case TXN_TRUNC_START:
start = cursor;
break;
case TXN_TRUNC_STOP:
stop = cursor;
break;
WT_ILLEGAL_VALUE_ERR(session);
}
/* Set the keys. */
if (start != NULL)
__wt_cursor_set_raw_key(start, &start_key);
if (stop != NULL)
__wt_cursor_set_raw_key(stop, &stop_key);
WT_TRET(session->iface.truncate(&session->iface, NULL,
start, stop, NULL));
/* If we opened a duplicate cursor, close it now. */
if (stop != NULL && stop != cursor)
WT_TRET(stop->close(stop));
WT_ERR(ret);
break;
WT_ILLEGAL_VALUE_ERR(session);
}
/* Reset the cursor so it doesn't block eviction. */
if (cursor != NULL)
WT_ERR(cursor->reset(cursor));
r->modified = 1;
err: if (ret != 0)
__wt_err(session, ret, "Operation failed during recovery");
return (ret);
}
/*
* __txn_commit_apply --
* Apply a commit record during recovery.
*/
static int
__txn_commit_apply(
WT_RECOVERY *r, WT_LSN *lsnp, const uint8_t **pp, const uint8_t *end)
{
WT_UNUSED(lsnp);
/* The logging subsystem zero-pads records. */
while (*pp < end && **pp)
WT_RET(__txn_op_apply(r, lsnp, pp, end));
return (0);
}
/*
* __txn_log_recover --
* Roll the log forward to recover committed changes.
*/
static int
__txn_log_recover(WT_SESSION_IMPL *session,
WT_ITEM *logrec, WT_LSN *lsnp, void *cookie, int firstrecord)
{
WT_RECOVERY *r;
const uint8_t *end, *p;
uint64_t txnid;
uint32_t rectype;
r = cookie;
p = LOG_SKIP_HEADER(logrec->data);
end = (const uint8_t *)logrec->data + logrec->size;
WT_UNUSED(firstrecord);
/* First, peek at the log record type. */
WT_RET(__wt_logrec_read(session, &p, end, &rectype));
switch (rectype) {
case WT_LOGREC_CHECKPOINT:
if (r->metadata_only)
WT_RET(__wt_txn_checkpoint_logread(
session, &p, end, &r->ckpt_lsn));
break;
case WT_LOGREC_COMMIT:
WT_RET(__wt_vunpack_uint(&p, WT_PTRDIFF(end, p), &txnid));
WT_UNUSED(txnid);
WT_RET(__txn_commit_apply(r, lsnp, &p, end));
break;
}
return (0);
}
/*
* __recovery_setup_file --
* Set up the recovery slot for a file.
*/
static int
__recovery_setup_file(WT_RECOVERY *r, const char *uri, const char *config)
{
WT_CONFIG_ITEM cval;
WT_LSN lsn;
uint32_t fileid;
WT_RET(__wt_config_getones(r->session, config, "id", &cval));
fileid = (uint32_t)cval.val;
/* Track the largest file ID we have seen. */
if (fileid > r->max_fileid)
r->max_fileid = fileid;
if (r->nfiles <= fileid) {
WT_RET(__wt_realloc_def(
r->session, &r->file_alloc, fileid + 1, &r->files));
r->nfiles = fileid + 1;
}
WT_RET(__wt_strdup(r->session, uri, &r->files[fileid].uri));
WT_RET(
__wt_config_getones(r->session, config, "checkpoint_lsn", &cval));
/* If there is checkpoint logged for the file, apply everything. */
if (cval.type != WT_CONFIG_ITEM_STRUCT)
WT_INIT_LSN(&lsn);
else if (sscanf(cval.str, "(%" PRIu32 ",%" PRIdMAX ")",
&lsn.file, (intmax_t*)&lsn.offset) != 2)
WT_RET_MSG(r->session, EINVAL,
"Failed to parse checkpoint LSN '%.*s'",
(int)cval.len, cval.str);
r->files[fileid].ckpt_lsn = lsn;
WT_RET(__wt_verbose(r->session, WT_VERB_RECOVERY,
"Recovering %s with id %u @ (%" PRIu32 ", %" PRIu64 ")",
uri, fileid, lsn.file, lsn.offset));
return (0);
}
/*
* __recovery_free --
* Free the recovery state.
*/
static int
__recovery_free(WT_RECOVERY *r)
{
WT_CURSOR *c;
WT_DECL_RET;
WT_SESSION_IMPL *session;
u_int i;
session = r->session;
for (i = 0; i < r->nfiles; i++) {
__wt_free(session, r->files[i].uri);
if ((c = r->files[i].c) != NULL)
WT_TRET(c->close(c));
}
__wt_free(session, r->files);
return (ret);
}
/*
* __recovery_file_scan --
* Scan the files referenced from the metadata and gather information
* about them for recovery.
*/
static int
__recovery_file_scan(WT_RECOVERY *r)
{
WT_DECL_RET;
WT_CURSOR *c;
const char *uri, *config;
int cmp;
/* Scan through all files in the metadata. */
c = r->files[0].c;
c->set_key(c, "file:");
if ((ret = c->search_near(c, &cmp)) != 0) {
/* Is the metadata empty? */
if (ret == WT_NOTFOUND)
ret = 0;
goto err;
}
if (cmp < 0)
WT_ERR_NOTFOUND_OK(c->next(c));
for (; ret == 0; ret = c->next(c)) {
WT_ERR(c->get_key(c, &uri));
if (!WT_PREFIX_MATCH(uri, "file:"))
break;
WT_ERR(c->get_value(c, &config));
WT_ERR(__recovery_setup_file(r, uri, config));
}
WT_ERR_NOTFOUND_OK(ret);
err: return (ret);
}
/*
* __wt_txn_recover --
* Run recovery.
*/
int
__wt_txn_recover(WT_SESSION_IMPL *session)
{
WT_CONNECTION_IMPL *conn;
WT_CURSOR *metac;
WT_DECL_RET;
WT_RECOVERY r;
struct WT_RECOVERY_FILE *metafile;
char *config;
int needs_rec, was_backup;
conn = S2C(session);
WT_CLEAR(r);
WT_INIT_LSN(&r.ckpt_lsn);
was_backup = F_ISSET(conn, WT_CONN_WAS_BACKUP) ? 1 : 0;
/* We need a real session for recovery. */
WT_RET(__wt_open_session(conn, NULL, NULL, &session));
F_SET(session, WT_SESSION_NO_LOGGING);
r.session = session;
WT_ERR(__wt_metadata_search(session, WT_METAFILE_URI, &config));
WT_ERR(__recovery_setup_file(&r, WT_METAFILE_URI, config));
WT_ERR(__wt_metadata_cursor(session, NULL, &metac));
metafile = &r.files[WT_METAFILE_ID];
metafile->c = metac;
/*
* If no log was found (including if logging is disabled), or if the
* last checkpoint was done with logging disabled, recovery should not
* run. Scan the metadata to figure out the largest file ID.
*/
if (!FLD_ISSET(S2C(session)->log_flags, WT_CONN_LOG_EXISTED) ||
WT_IS_MAX_LSN(&metafile->ckpt_lsn)) {
WT_ERR(__recovery_file_scan(&r));
conn->next_file_id = r.max_fileid;
goto done;
}
/*
* First, do a pass through the log to recover the metadata, and
* establish the last checkpoint LSN. Skip this when opening a hot
* backup: we already have the correct metadata in that case.
*/
if (!was_backup) {
r.metadata_only = 1;
if (WT_IS_INIT_LSN(&metafile->ckpt_lsn))
WT_ERR(__wt_log_scan(session,
NULL, WT_LOGSCAN_FIRST, __txn_log_recover, &r));
else {
/*
* Start at the last checkpoint LSN referenced in the
* metadata. If we see the end of a checkpoint while
* scanning, we will change the full scan to start from
* there.
*/
r.ckpt_lsn = metafile->ckpt_lsn;
WT_ERR(__wt_log_scan(session,
&metafile->ckpt_lsn, 0, __txn_log_recover, &r));
}
}
/* Scan the metadata to find the live files and their IDs. */
WT_ERR(__recovery_file_scan(&r));
/*
* We no longer need the metadata cursor: close it to avoid pinning any
* resources that could block eviction during recovery.
*/
r.files[0].c = NULL;
WT_ERR(metac->close(metac));
/*
* Now, recover all the files apart from the metadata.
* Pass WT_LOGSCAN_RECOVER so that old logs get truncated.
*/
r.metadata_only = 0;
WT_ERR(__wt_verbose(session, WT_VERB_RECOVERY,
"Main recovery loop: starting at %u/%" PRIuMAX,
r.ckpt_lsn.file, (uintmax_t)r.ckpt_lsn.offset));
WT_ERR(__wt_log_needs_recovery(session, &r.ckpt_lsn, &needs_rec));
/*
* Check if the database was shut down cleanly. If not
* return an error if the user does not want automatic
* recovery.
*/
if (needs_rec && FLD_ISSET(conn->log_flags, WT_CONN_LOG_RECOVER_ERR))
WT_ERR(WT_RUN_RECOVERY);
/*
* Always run recovery even if it was a clean shutdown.
* We can consider skipping it in the future.
*/
if (WT_IS_INIT_LSN(&r.ckpt_lsn))
WT_ERR(__wt_log_scan(session, NULL,
WT_LOGSCAN_FIRST | WT_LOGSCAN_RECOVER,
__txn_log_recover, &r));
else
WT_ERR(__wt_log_scan(session, &r.ckpt_lsn,
WT_LOGSCAN_RECOVER, __txn_log_recover, &r));
conn->next_file_id = r.max_fileid;
/*
* If recovery ran successfully forcibly log a checkpoint so the next
* open is fast and keep the metadata up to date with the checkpoint
* LSN and archiving.
*/
WT_ERR(session->iface.checkpoint(&session->iface, "force=1"));
done:
err: WT_TRET(__recovery_free(&r));
__wt_free(session, config);
WT_TRET(session->iface.close(&session->iface, NULL));
return (ret);
}
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