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s3: separate tdb validation code out into its own source file
So this gets now linked only into its single user: winbindd (needed by winbindd_cache.c) Michael
This commit is contained in:
Michael Adam
@ -630,487 +630,3 @@ NTSTATUS map_nt_error_from_tdb(enum TDB_ERROR err)
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return NT_STATUS_INTERNAL_ERROR;
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}
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/*********************************************************************
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* the following is a generic validation mechanism for tdbs.
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*********************************************************************/
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/*
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* internal validation function, executed by the child.
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*/
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static int tdb_validate_child(struct tdb_context *tdb,
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tdb_validate_data_func validate_fn)
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{
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int ret = 1;
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int num_entries = 0;
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struct tdb_validation_status v_status;
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v_status.tdb_error = False;
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v_status.bad_freelist = False;
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v_status.bad_entry = False;
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v_status.unknown_key = False;
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v_status.success = True;
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if (!tdb) {
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v_status.tdb_error = True;
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v_status.success = False;
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goto out;
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}
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/* Check if the tdb's freelist is good. */
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if (tdb_validate_freelist(tdb, &num_entries) == -1) {
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v_status.bad_freelist = True;
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v_status.success = False;
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goto out;
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}
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DEBUG(10,("tdb_validate_child: tdb %s freelist has %d entries\n",
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tdb_name(tdb), num_entries));
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/* Now traverse the tdb to validate it. */
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num_entries = tdb_traverse(tdb, validate_fn, (void *)&v_status);
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if (!v_status.success) {
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goto out;
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} else if (num_entries == -1) {
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v_status.tdb_error = True;
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v_status.success = False;
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goto out;
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}
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DEBUG(10,("tdb_validate_child: tdb %s is good with %d entries\n",
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tdb_name(tdb), num_entries));
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ret = 0; /* Cache is good. */
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out:
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DEBUG(10, ("tdb_validate_child: summary of validation status:\n"));
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DEBUGADD(10,(" * tdb error: %s\n", v_status.tdb_error ? "yes" : "no"));
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DEBUGADD(10,(" * bad freelist: %s\n",v_status.bad_freelist?"yes":"no"));
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DEBUGADD(10,(" * bad entry: %s\n", v_status.bad_entry ? "yes" : "no"));
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DEBUGADD(10,(" * unknown key: %s\n", v_status.unknown_key?"yes":"no"));
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DEBUGADD(10,(" => overall success: %s\n", v_status.success?"yes":"no"));
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return ret;
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}
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/*
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* tdb validation function.
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* returns 0 if tdb is ok, != 0 if it isn't.
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* this function expects an opened tdb.
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*/
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int tdb_validate(struct tdb_context *tdb, tdb_validate_data_func validate_fn)
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{
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pid_t child_pid = -1;
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int child_status = 0;
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int wait_pid = 0;
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int ret = 1;
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if (tdb == NULL) {
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DEBUG(1, ("Error: tdb_validate called with tdb == NULL\n"));
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return ret;
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}
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DEBUG(5, ("tdb_validate called for tdb '%s'\n", tdb_name(tdb)));
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/* fork and let the child do the validation.
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* benefit: no need to twist signal handlers and panic functions.
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* just let the child panic. we catch the signal. */
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DEBUG(10, ("tdb_validate: forking to let child do validation.\n"));
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child_pid = sys_fork();
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if (child_pid == 0) {
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/* child code */
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DEBUG(10, ("tdb_validate (validation child): created\n"));
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DEBUG(10, ("tdb_validate (validation child): "
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"calling tdb_validate_child\n"));
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exit(tdb_validate_child(tdb, validate_fn));
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}
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else if (child_pid < 0) {
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DEBUG(1, ("tdb_validate: fork for validation failed.\n"));
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goto done;
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}
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/* parent */
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DEBUG(10, ("tdb_validate: fork succeeded, child PID = %d\n",child_pid));
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DEBUG(10, ("tdb_validate: waiting for child to finish...\n"));
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while ((wait_pid = sys_waitpid(child_pid, &child_status, 0)) < 0) {
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if (errno == EINTR) {
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DEBUG(10, ("tdb_validate: got signal during waitpid, "
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"retrying\n"));
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errno = 0;
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continue;
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}
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DEBUG(1, ("tdb_validate: waitpid failed with error '%s'.\n",
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strerror(errno)));
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goto done;
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}
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if (wait_pid != child_pid) {
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DEBUG(1, ("tdb_validate: waitpid returned pid %d, "
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"but %d was expected\n", wait_pid, child_pid));
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goto done;
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}
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DEBUG(10, ("tdb_validate: validating child returned.\n"));
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if (WIFEXITED(child_status)) {
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DEBUG(10, ("tdb_validate: child exited, code %d.\n",
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WEXITSTATUS(child_status)));
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ret = WEXITSTATUS(child_status);
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}
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if (WIFSIGNALED(child_status)) {
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DEBUG(10, ("tdb_validate: child terminated by signal %d\n",
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WTERMSIG(child_status)));
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#ifdef WCOREDUMP
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if (WCOREDUMP(child_status)) {
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DEBUGADD(10, ("core dumped\n"));
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}
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#endif
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ret = WTERMSIG(child_status);
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}
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if (WIFSTOPPED(child_status)) {
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DEBUG(10, ("tdb_validate: child was stopped by signal %d\n",
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WSTOPSIG(child_status)));
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ret = WSTOPSIG(child_status);
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}
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done:
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DEBUG(5, ("tdb_validate returning code '%d' for tdb '%s'\n", ret,
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tdb_name(tdb)));
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return ret;
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}
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/*
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* tdb validation function.
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* returns 0 if tdb is ok, != 0 if it isn't.
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* this is a wrapper around the actual validation function that opens and closes
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* the tdb.
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*/
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int tdb_validate_open(const char *tdb_path, tdb_validate_data_func validate_fn)
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{
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TDB_CONTEXT *tdb = NULL;
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int ret = 1;
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DEBUG(5, ("tdb_validate_open called for tdb '%s'\n", tdb_path));
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tdb = tdb_open_log(tdb_path, 0, TDB_DEFAULT, O_RDONLY, 0);
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if (!tdb) {
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DEBUG(1, ("Error opening tdb %s\n", tdb_path));
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return ret;
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}
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ret = tdb_validate(tdb, validate_fn);
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tdb_close(tdb);
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return ret;
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}
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/*
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* tdb backup function and helpers for tdb_validate wrapper with backup
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* handling.
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*/
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/* this structure eliminates the need for a global overall status for
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* the traverse-copy */
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struct tdb_copy_data {
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struct tdb_context *dst;
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bool success;
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};
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static int traverse_copy_fn(struct tdb_context *tdb, TDB_DATA key,
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TDB_DATA dbuf, void *private_data)
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{
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struct tdb_copy_data *data = (struct tdb_copy_data *)private_data;
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if (tdb_store(data->dst, key, dbuf, TDB_INSERT) != 0) {
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DEBUG(4, ("Failed to insert into %s: %s\n", tdb_name(data->dst),
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strerror(errno)));
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data->success = False;
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return 1;
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}
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return 0;
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}
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static int tdb_copy(struct tdb_context *src, struct tdb_context *dst)
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{
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struct tdb_copy_data data;
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int count;
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data.dst = dst;
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data.success = True;
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count = tdb_traverse(src, traverse_copy_fn, (void *)(&data));
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if ((count < 0) || (data.success == False)) {
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return -1;
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}
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return count;
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}
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static int tdb_verify_basic(struct tdb_context *tdb)
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{
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return tdb_traverse(tdb, NULL, NULL);
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}
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/* this backup function is essentially taken from lib/tdb/tools/tdbbackup.tdb
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*/
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static int tdb_backup(TALLOC_CTX *ctx, const char *src_path,
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const char *dst_path, int hash_size)
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{
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struct tdb_context *src_tdb = NULL;
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struct tdb_context *dst_tdb = NULL;
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char *tmp_path = NULL;
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struct stat st;
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int count1, count2;
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int saved_errno = 0;
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int ret = -1;
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if (stat(src_path, &st) != 0) {
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DEBUG(3, ("Could not stat '%s': %s\n", src_path,
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strerror(errno)));
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goto done;
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}
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/* open old tdb RDWR - so we can lock it */
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src_tdb = tdb_open_log(src_path, 0, TDB_DEFAULT, O_RDWR, 0);
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if (src_tdb == NULL) {
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DEBUG(3, ("Failed to open tdb '%s'\n", src_path));
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goto done;
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}
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if (tdb_lockall(src_tdb) != 0) {
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DEBUG(3, ("Failed to lock tdb '%s'\n", src_path));
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goto done;
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}
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tmp_path = talloc_asprintf(ctx, "%s%s", dst_path, ".tmp");
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unlink(tmp_path);
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dst_tdb = tdb_open_log(tmp_path,
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hash_size ? hash_size : tdb_hash_size(src_tdb),
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TDB_DEFAULT, O_RDWR | O_CREAT | O_EXCL,
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st.st_mode & 0777);
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if (dst_tdb == NULL) {
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DEBUG(3, ("Error creating tdb '%s': %s\n", tmp_path,
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strerror(errno)));
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saved_errno = errno;
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unlink(tmp_path);
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goto done;
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}
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count1 = tdb_copy(src_tdb, dst_tdb);
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if (count1 < 0) {
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DEBUG(3, ("Failed to copy tdb '%s': %s\n", src_path,
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strerror(errno)));
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tdb_close(dst_tdb);
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goto done;
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}
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/* reopen ro and do basic verification */
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tdb_close(dst_tdb);
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dst_tdb = tdb_open_log(tmp_path, 0, TDB_DEFAULT, O_RDONLY, 0);
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if (!dst_tdb) {
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DEBUG(3, ("Failed to reopen tdb '%s': %s\n", tmp_path,
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strerror(errno)));
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goto done;
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}
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count2 = tdb_verify_basic(dst_tdb);
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if (count2 != count1) {
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DEBUG(3, ("Failed to verify result of copying tdb '%s'.\n",
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src_path));
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tdb_close(dst_tdb);
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goto done;
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}
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DEBUG(10, ("tdb_backup: successfully copied %d entries\n", count1));
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/* make sure the new tdb has reached stable storage
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* then rename it to its destination */
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fsync(tdb_fd(dst_tdb));
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tdb_close(dst_tdb);
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unlink(dst_path);
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if (rename(tmp_path, dst_path) != 0) {
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DEBUG(3, ("Failed to rename '%s' to '%s': %s\n",
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tmp_path, dst_path, strerror(errno)));
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goto done;
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}
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/* success */
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ret = 0;
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done:
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if (src_tdb != NULL) {
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tdb_close(src_tdb);
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}
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if (tmp_path != NULL) {
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unlink(tmp_path);
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TALLOC_FREE(tmp_path);
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}
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if (saved_errno != 0) {
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errno = saved_errno;
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}
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return ret;
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}
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static int rename_file_with_suffix(TALLOC_CTX *ctx, const char *path,
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const char *suffix)
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{
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int ret = -1;
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char *dst_path;
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dst_path = talloc_asprintf(ctx, "%s%s", path, suffix);
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ret = (rename(path, dst_path) != 0);
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if (ret == 0) {
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DEBUG(5, ("moved '%s' to '%s'\n", path, dst_path));
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} else if (errno == ENOENT) {
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DEBUG(3, ("file '%s' does not exist - so not moved\n", path));
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ret = 0;
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} else {
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DEBUG(3, ("error renaming %s to %s: %s\n", path, dst_path,
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strerror(errno)));
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}
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TALLOC_FREE(dst_path);
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return ret;
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}
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/*
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* do a backup of a tdb, moving the destination out of the way first
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*/
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static int tdb_backup_with_rotate(TALLOC_CTX *ctx, const char *src_path,
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const char *dst_path, int hash_size,
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const char *rotate_suffix,
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bool retry_norotate_if_nospc,
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bool rename_as_last_resort_if_nospc)
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{
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int ret;
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rename_file_with_suffix(ctx, dst_path, rotate_suffix);
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ret = tdb_backup(ctx, src_path, dst_path, hash_size);
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if (ret != 0) {
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DEBUG(10, ("backup of %s failed: %s\n", src_path, strerror(errno)));
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}
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if ((ret != 0) && (errno == ENOSPC) && retry_norotate_if_nospc)
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{
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char *rotate_path = talloc_asprintf(ctx, "%s%s", dst_path,
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rotate_suffix);
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DEBUG(10, ("backup of %s failed due to lack of space\n",
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src_path));
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DEBUGADD(10, ("trying to free some space by removing rotated "
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"dst %s\n", rotate_path));
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if (unlink(rotate_path) == -1) {
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DEBUG(10, ("unlink of %s failed: %s\n", rotate_path,
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strerror(errno)));
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} else {
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ret = tdb_backup(ctx, src_path, dst_path, hash_size);
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}
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TALLOC_FREE(rotate_path);
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}
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if ((ret != 0) && (errno == ENOSPC) && rename_as_last_resort_if_nospc)
|
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{
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DEBUG(10, ("backup of %s failed due to lack of space\n",
|
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src_path));
|
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DEBUGADD(10, ("using 'rename' as a last resort\n"));
|
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ret = rename(src_path, dst_path);
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
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/*
|
||||
* validation function with backup handling:
|
||||
*
|
||||
* - calls tdb_validate
|
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* - if the tdb is ok, create a backup "name.bak", possibly moving
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* existing backup to name.bak.old,
|
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* return 0 (success) even if the backup fails
|
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* - if the tdb is corrupt:
|
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* - move the tdb to "name.corrupt"
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* - check if there is valid backup.
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* if so, restore the backup.
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* if restore is successful, return 0 (success),
|
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* - otherwise return -1 (failure)
|
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*/
|
||||
int tdb_validate_and_backup(const char *tdb_path,
|
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tdb_validate_data_func validate_fn)
|
||||
{
|
||||
int ret = -1;
|
||||
const char *backup_suffix = ".bak";
|
||||
const char *corrupt_suffix = ".corrupt";
|
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const char *rotate_suffix = ".old";
|
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char *tdb_path_backup;
|
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struct stat st;
|
||||
TALLOC_CTX *ctx = NULL;
|
||||
|
||||
ctx = talloc_new(NULL);
|
||||
if (ctx == NULL) {
|
||||
DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
|
||||
goto done;
|
||||
}
|
||||
|
||||
tdb_path_backup = talloc_asprintf(ctx, "%s%s", tdb_path, backup_suffix);
|
||||
|
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ret = tdb_validate_open(tdb_path, validate_fn);
|
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|
||||
if (ret == 0) {
|
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DEBUG(1, ("tdb '%s' is valid\n", tdb_path));
|
||||
ret = tdb_backup_with_rotate(ctx, tdb_path, tdb_path_backup, 0,
|
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rotate_suffix, True, False);
|
||||
if (ret != 0) {
|
||||
DEBUG(1, ("Error creating backup of tdb '%s'\n",
|
||||
tdb_path));
|
||||
/* the actual validation was successful: */
|
||||
ret = 0;
|
||||
} else {
|
||||
DEBUG(1, ("Created backup '%s' of tdb '%s'\n",
|
||||
tdb_path_backup, tdb_path));
|
||||
}
|
||||
} else {
|
||||
DEBUG(1, ("tdb '%s' is invalid\n", tdb_path));
|
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|
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ret =stat(tdb_path_backup, &st);
|
||||
if (ret != 0) {
|
||||
DEBUG(5, ("Could not stat '%s': %s\n", tdb_path_backup,
|
||||
strerror(errno)));
|
||||
DEBUG(1, ("No backup found.\n"));
|
||||
} else {
|
||||
DEBUG(1, ("backup '%s' found.\n", tdb_path_backup));
|
||||
ret = tdb_validate_open(tdb_path_backup, validate_fn);
|
||||
if (ret != 0) {
|
||||
DEBUG(1, ("Backup '%s' is invalid.\n",
|
||||
tdb_path_backup));
|
||||
}
|
||||
}
|
||||
|
||||
if (ret != 0) {
|
||||
int renamed = rename_file_with_suffix(ctx, tdb_path,
|
||||
corrupt_suffix);
|
||||
if (renamed != 0) {
|
||||
DEBUG(1, ("Error moving tdb to '%s%s'\n",
|
||||
tdb_path, corrupt_suffix));
|
||||
} else {
|
||||
DEBUG(1, ("Corrupt tdb stored as '%s%s'\n",
|
||||
tdb_path, corrupt_suffix));
|
||||
}
|
||||
goto done;
|
||||
}
|
||||
|
||||
DEBUG(1, ("valid backup '%s' found\n", tdb_path_backup));
|
||||
ret = tdb_backup_with_rotate(ctx, tdb_path_backup, tdb_path, 0,
|
||||
corrupt_suffix, True, True);
|
||||
if (ret != 0) {
|
||||
DEBUG(1, ("Error restoring backup from '%s'\n",
|
||||
tdb_path_backup));
|
||||
} else {
|
||||
DEBUG(1, ("Restored tdb backup from '%s'\n",
|
||||
tdb_path_backup));
|
||||
}
|
||||
}
|
||||
|
||||
done:
|
||||
TALLOC_FREE(ctx);
|
||||
return ret;
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user