1 /* Copyright (c) 2009, 2010, 2011, 2012 Nicira, Inc.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
30 #include "ovsdb-error.h"
32 #include "socket-util.h"
35 #include "transaction.h"
40 VLOG_DEFINE_THIS_MODULE(ovsdb_file
);
42 /* Minimum number of milliseconds between database compactions. */
43 #define COMPACT_MIN_MSEC (10 * 60 * 1000) /* 10 minutes. */
45 /* Minimum number of milliseconds between trying to compact the database if
46 * compacting fails. */
47 #define COMPACT_RETRY_MSEC (60 * 1000) /* 1 minute. */
49 /* A transaction being converted to JSON for writing to a file. */
50 struct ovsdb_file_txn
{
51 struct json
*json
; /* JSON for the whole transaction. */
52 struct json
*table_json
; /* JSON for 'table''s transaction. */
53 struct ovsdb_table
*table
; /* Table described in 'table_json'. */
56 static void ovsdb_file_txn_init(struct ovsdb_file_txn
*);
57 static void ovsdb_file_txn_add_row(struct ovsdb_file_txn
*,
58 const struct ovsdb_row
*old
,
59 const struct ovsdb_row
*new,
60 const unsigned long int *changed
);
61 static struct ovsdb_error
*ovsdb_file_txn_commit(struct json
*,
66 static struct ovsdb_error
*ovsdb_file_open__(const char *file_name
,
67 const struct ovsdb_schema
*,
68 bool read_only
, struct ovsdb
**,
69 struct ovsdb_file
**);
70 static struct ovsdb_error
*ovsdb_file_txn_from_json(
71 struct ovsdb
*, const struct json
*, bool converting
,
72 long long int *date
, struct ovsdb_txn
**);
73 static struct ovsdb_error
*ovsdb_file_create(struct ovsdb
*,
75 const char *file_name
,
76 long long int oldest_commit
,
77 unsigned int n_transactions
,
78 struct ovsdb_file
**filep
);
80 /* Opens database 'file_name' and stores a pointer to the new database in
81 * '*dbp'. If 'read_only' is false, then the database will be locked and
82 * changes to the database will be written to disk. If 'read_only' is true,
83 * the database will not be locked and changes to the database will persist
84 * only as long as the "struct ovsdb".
86 * If 'filep' is nonnull and 'read_only' is false, then on success sets
87 * '*filep' to an ovsdb_file that represents the open file. This ovsdb_file
88 * persists until '*dbp' is destroyed.
90 * On success, returns NULL. On failure, returns an ovsdb_error (which the
91 * caller must destroy) and sets '*dbp' and '*filep' to NULL. */
93 ovsdb_file_open(const char *file_name
, bool read_only
,
94 struct ovsdb
**dbp
, struct ovsdb_file
**filep
)
96 return ovsdb_file_open__(file_name
, NULL
, read_only
, dbp
, filep
);
99 /* Opens database 'file_name' with an alternate schema. The specified 'schema'
100 * is used to interpret the data in 'file_name', ignoring the schema actually
101 * stored in the file. Data in the file for tables or columns that do not
102 * exist in 'schema' are ignored, but the ovsdb file format must otherwise be
103 * observed, including column constraints.
105 * This function can be useful for upgrading or downgrading databases to
106 * "almost-compatible" formats.
108 * The database will not be locked. Changes to the database will persist only
109 * as long as the "struct ovsdb".
111 * On success, stores a pointer to the new database in '*dbp' and returns a
112 * null pointer. On failure, returns an ovsdb_error (which the caller must
113 * destroy) and sets '*dbp' to NULL. */
115 ovsdb_file_open_as_schema(const char *file_name
,
116 const struct ovsdb_schema
*schema
,
119 return ovsdb_file_open__(file_name
, schema
, true, dbp
, NULL
);
122 static struct ovsdb_error
*
123 ovsdb_file_open_log(const char *file_name
, enum ovsdb_log_open_mode open_mode
,
124 struct ovsdb_log
**logp
, struct ovsdb_schema
**schemap
)
126 struct ovsdb_schema
*schema
= NULL
;
127 struct ovsdb_log
*log
= NULL
;
128 struct ovsdb_error
*error
;
129 struct json
*json
= NULL
;
131 ovs_assert(logp
|| schemap
);
133 error
= ovsdb_log_open(file_name
, open_mode
, -1, &log
);
138 error
= ovsdb_log_read(log
, &json
);
142 error
= ovsdb_io_error(EOF
, "%s: database file contains no schema",
148 error
= ovsdb_schema_from_json(json
, &schema
);
150 error
= ovsdb_wrap_error(error
,
151 "failed to parse \"%s\" as ovsdb schema",
161 ovsdb_log_close(log
);
169 ovsdb_log_close(log
);
180 static struct ovsdb_error
*
181 ovsdb_file_open__(const char *file_name
,
182 const struct ovsdb_schema
*alternate_schema
,
183 bool read_only
, struct ovsdb
**dbp
,
184 struct ovsdb_file
**filep
)
186 enum ovsdb_log_open_mode open_mode
;
187 long long int oldest_commit
;
188 unsigned int n_transactions
;
189 struct ovsdb_schema
*schema
= NULL
;
190 struct ovsdb_error
*error
;
191 struct ovsdb_log
*log
;
193 struct ovsdb
*db
= NULL
;
195 /* In read-only mode there is no ovsdb_file so 'filep' must be null. */
196 ovs_assert(!(read_only
&& filep
));
198 open_mode
= read_only
? OVSDB_LOG_READ_ONLY
: OVSDB_LOG_READ_WRITE
;
199 error
= ovsdb_file_open_log(file_name
, open_mode
, &log
,
200 alternate_schema
? NULL
: &schema
);
205 db
= ovsdb_create(schema
? schema
: ovsdb_schema_clone(alternate_schema
));
207 oldest_commit
= LLONG_MAX
;
209 while ((error
= ovsdb_log_read(log
, &json
)) == NULL
&& json
) {
210 struct ovsdb_txn
*txn
;
213 error
= ovsdb_file_txn_from_json(db
, json
, alternate_schema
!= NULL
,
217 ovsdb_log_unread(log
);
222 if (date
< oldest_commit
) {
223 oldest_commit
= date
;
226 error
= ovsdb_txn_commit(txn
, false);
228 ovsdb_log_unread(log
);
233 /* Log error but otherwise ignore it. Probably the database just got
234 * truncated due to power failure etc. and we should use its current
236 char *msg
= ovsdb_error_to_string(error
);
240 ovsdb_error_destroy(error
);
244 struct ovsdb_file
*file
;
246 error
= ovsdb_file_create(db
, log
, file_name
, oldest_commit
,
247 n_transactions
, &file
);
255 ovsdb_log_close(log
);
267 ovsdb_log_close(log
);
271 static struct ovsdb_error
*
272 ovsdb_file_update_row_from_json(struct ovsdb_row
*row
, bool converting
,
273 const struct json
*json
)
275 struct ovsdb_table_schema
*schema
= row
->table
->schema
;
276 struct ovsdb_error
*error
;
277 struct shash_node
*node
;
279 if (json
->type
!= JSON_OBJECT
) {
280 return ovsdb_syntax_error(json
, NULL
, "row must be JSON object");
283 SHASH_FOR_EACH (node
, json_object(json
)) {
284 const char *column_name
= node
->name
;
285 const struct ovsdb_column
*column
;
286 struct ovsdb_datum datum
;
288 column
= ovsdb_table_schema_get_column(schema
, column_name
);
293 return ovsdb_syntax_error(json
, "unknown column",
294 "No column %s in table %s.",
295 column_name
, schema
->name
);
298 error
= ovsdb_datum_from_json(&datum
, &column
->type
, node
->data
, NULL
);
302 ovsdb_datum_swap(&row
->fields
[column
->index
], &datum
);
303 ovsdb_datum_destroy(&datum
, &column
->type
);
309 static struct ovsdb_error
*
310 ovsdb_file_txn_row_from_json(struct ovsdb_txn
*txn
, struct ovsdb_table
*table
,
312 const struct uuid
*row_uuid
, struct json
*json
)
314 const struct ovsdb_row
*row
= ovsdb_table_get_row(table
, row_uuid
);
315 if (json
->type
== JSON_NULL
) {
317 return ovsdb_syntax_error(NULL
, NULL
, "transaction deletes "
318 "row "UUID_FMT
" that does not exist",
319 UUID_ARGS(row_uuid
));
321 ovsdb_txn_row_delete(txn
, row
);
324 return ovsdb_file_update_row_from_json(ovsdb_txn_row_modify(txn
, row
),
327 struct ovsdb_error
*error
;
328 struct ovsdb_row
*new;
330 new = ovsdb_row_create(table
);
331 *ovsdb_row_get_uuid_rw(new) = *row_uuid
;
332 error
= ovsdb_file_update_row_from_json(new, converting
, json
);
334 ovsdb_row_destroy(new);
336 ovsdb_txn_row_insert(txn
, new);
342 static struct ovsdb_error
*
343 ovsdb_file_txn_table_from_json(struct ovsdb_txn
*txn
,
344 struct ovsdb_table
*table
,
345 bool converting
, struct json
*json
)
347 struct shash_node
*node
;
349 if (json
->type
!= JSON_OBJECT
) {
350 return ovsdb_syntax_error(json
, NULL
, "object expected");
353 SHASH_FOR_EACH (node
, json
->u
.object
) {
354 const char *uuid_string
= node
->name
;
355 struct json
*txn_row_json
= node
->data
;
356 struct ovsdb_error
*error
;
357 struct uuid row_uuid
;
359 if (!uuid_from_string(&row_uuid
, uuid_string
)) {
360 return ovsdb_syntax_error(json
, NULL
, "\"%s\" is not a valid UUID",
364 error
= ovsdb_file_txn_row_from_json(txn
, table
, converting
,
365 &row_uuid
, txn_row_json
);
374 /* Converts 'json' to an ovsdb_txn for 'db', storing the new transaction in
375 * '*txnp'. Returns NULL if successful, otherwise an error.
377 * If 'converting' is true, then unknown table and column names are ignored
378 * (which can ease upgrading and downgrading schemas); otherwise, they are
381 * If successful, the date associated with the transaction, as the number of
382 * milliseconds since the epoch, is stored in '*date'. If the transaction does
383 * not include a date, LLONG_MAX is stored. */
384 static struct ovsdb_error
*
385 ovsdb_file_txn_from_json(struct ovsdb
*db
, const struct json
*json
,
386 bool converting
, long long int *date
,
387 struct ovsdb_txn
**txnp
)
389 struct ovsdb_error
*error
;
390 struct shash_node
*node
;
391 struct ovsdb_txn
*txn
;
396 if (json
->type
!= JSON_OBJECT
) {
397 return ovsdb_syntax_error(json
, NULL
, "object expected");
400 txn
= ovsdb_txn_create(db
);
401 SHASH_FOR_EACH (node
, json
->u
.object
) {
402 const char *table_name
= node
->name
;
403 struct json
*node_json
= node
->data
;
404 struct ovsdb_table
*table
;
406 table
= shash_find_data(&db
->tables
, table_name
);
408 if (!strcmp(table_name
, "_date")
409 && node_json
->type
== JSON_INTEGER
) {
410 *date
= json_integer(node_json
);
412 } else if (!strcmp(table_name
, "_comment") || converting
) {
416 error
= ovsdb_syntax_error(json
, "unknown table",
417 "No table named %s.", table_name
);
421 error
= ovsdb_file_txn_table_from_json(txn
, table
, converting
,
431 ovsdb_txn_abort(txn
);
435 static struct ovsdb_error
*
436 ovsdb_file_save_copy__(const char *file_name
, int locking
,
437 const char *comment
, const struct ovsdb
*db
,
438 struct ovsdb_log
**logp
)
440 const struct shash_node
*node
;
441 struct ovsdb_file_txn ftxn
;
442 struct ovsdb_error
*error
;
443 struct ovsdb_log
*log
;
446 error
= ovsdb_log_open(file_name
, OVSDB_LOG_CREATE
, locking
, &log
);
452 json
= ovsdb_schema_to_json(db
->schema
);
453 error
= ovsdb_log_write(log
, json
);
460 ovsdb_file_txn_init(&ftxn
);
461 SHASH_FOR_EACH (node
, &db
->tables
) {
462 const struct ovsdb_table
*table
= node
->data
;
463 const struct ovsdb_row
*row
;
465 HMAP_FOR_EACH (row
, hmap_node
, &table
->rows
) {
466 ovsdb_file_txn_add_row(&ftxn
, NULL
, row
, NULL
);
469 error
= ovsdb_file_txn_commit(ftxn
.json
, comment
, true, log
);
480 ovsdb_log_close(log
);
487 /* Saves a snapshot of 'db''s current contents as 'file_name'. If 'comment' is
488 * nonnull, then it is added along with the data contents and can be viewed
489 * with "ovsdb-tool show-log".
491 * 'locking' is passed along to ovsdb_log_open() untouched. */
493 ovsdb_file_save_copy(const char *file_name
, int locking
,
494 const char *comment
, const struct ovsdb
*db
)
496 return ovsdb_file_save_copy__(file_name
, locking
, comment
, db
, NULL
);
499 /* Opens database 'file_name', reads its schema, and closes it. On success,
500 * stores the schema into '*schemap' and returns NULL; the caller then owns the
501 * schema. On failure, returns an ovsdb_error (which the caller must destroy)
502 * and sets '*dbp' to NULL. */
504 ovsdb_file_read_schema(const char *file_name
, struct ovsdb_schema
**schemap
)
506 ovs_assert(schemap
!= NULL
);
507 return ovsdb_file_open_log(file_name
, OVSDB_LOG_READ_ONLY
, NULL
, schemap
);
510 /* Replica implementation. */
513 struct ovsdb_replica replica
;
515 struct ovsdb_log
*log
;
517 long long int oldest_commit
;
518 long long int next_compact
;
519 unsigned int n_transactions
;
522 static const struct ovsdb_replica_class ovsdb_file_class
;
524 static struct ovsdb_error
*
525 ovsdb_file_create(struct ovsdb
*db
, struct ovsdb_log
*log
,
526 const char *file_name
,
527 long long int oldest_commit
,
528 unsigned int n_transactions
,
529 struct ovsdb_file
**filep
)
531 long long int now
= time_msec();
532 struct ovsdb_file
*file
;
536 /* Use the absolute name of the file because ovsdb-server opens its
537 * database before daemonize() chdirs to "/". */
538 deref_name
= follow_symlinks(file_name
);
539 abs_name
= abs_file_name(NULL
, deref_name
);
543 return ovsdb_io_error(0, "could not determine current "
544 "working directory");
547 file
= xmalloc(sizeof *file
);
548 ovsdb_replica_init(&file
->replica
, &ovsdb_file_class
);
551 file
->file_name
= abs_name
;
552 file
->oldest_commit
= MIN(oldest_commit
, now
);
553 file
->next_compact
= file
->oldest_commit
+ COMPACT_MIN_MSEC
;
554 file
->n_transactions
= n_transactions
;
555 ovsdb_add_replica(db
, &file
->replica
);
561 static struct ovsdb_file
*
562 ovsdb_file_cast(struct ovsdb_replica
*replica
)
564 ovs_assert(replica
->class == &ovsdb_file_class
);
565 return CONTAINER_OF(replica
, struct ovsdb_file
, replica
);
569 ovsdb_file_change_cb(const struct ovsdb_row
*old
,
570 const struct ovsdb_row
*new,
571 const unsigned long int *changed
,
574 struct ovsdb_file_txn
*ftxn
= ftxn_
;
575 ovsdb_file_txn_add_row(ftxn
, old
, new, changed
);
579 static struct ovsdb_error
*
580 ovsdb_file_commit(struct ovsdb_replica
*replica
,
581 const struct ovsdb_txn
*txn
, bool durable
)
583 struct ovsdb_file
*file
= ovsdb_file_cast(replica
);
584 struct ovsdb_file_txn ftxn
;
585 struct ovsdb_error
*error
;
587 ovsdb_file_txn_init(&ftxn
);
588 ovsdb_txn_for_each_change(txn
, ovsdb_file_change_cb
, &ftxn
);
590 /* Nothing to commit. */
594 error
= ovsdb_file_txn_commit(ftxn
.json
, ovsdb_txn_get_comment(txn
),
599 file
->n_transactions
++;
601 /* If it has been at least COMPACT_MIN_MSEC ms since the last time we
602 * compacted (or at least COMPACT_RETRY_MSEC ms since the last time we
603 * tried), and if there are at least 100 transactions in the database, and
604 * if the database is at least 10 MB, then compact the database. */
605 if (time_msec() >= file
->next_compact
606 && file
->n_transactions
>= 100
607 && ovsdb_log_get_offset(file
->log
) >= 10 * 1024 * 1024)
609 error
= ovsdb_file_compact(file
);
611 char *s
= ovsdb_error_to_string(error
);
612 ovsdb_error_destroy(error
);
613 VLOG_WARN("%s: compacting database failed (%s), retrying in "
615 file
->file_name
, s
, COMPACT_RETRY_MSEC
/ 1000);
618 file
->next_compact
= time_msec() + COMPACT_RETRY_MSEC
;
626 ovsdb_file_compact(struct ovsdb_file
*file
)
628 struct ovsdb_log
*new_log
= NULL
;
629 struct lockfile
*tmp_lock
= NULL
;
630 struct ovsdb_error
*error
;
631 char *tmp_name
= NULL
;
632 char *comment
= NULL
;
635 comment
= xasprintf("compacting database online "
636 "(%.3f seconds old, %u transactions, %llu bytes)",
637 (time_msec() - file
->oldest_commit
) / 1000.0,
638 file
->n_transactions
,
639 (unsigned long long) ovsdb_log_get_offset(file
->log
));
640 VLOG_INFO("%s: %s", file
->file_name
, comment
);
642 /* Commit the old version, so that we can be assured that we'll eventually
643 * have either the old or the new version. */
644 error
= ovsdb_log_commit(file
->log
);
649 /* Lock temporary file. */
650 tmp_name
= xasprintf("%s.tmp", file
->file_name
);
651 retval
= lockfile_lock(tmp_name
, &tmp_lock
);
653 error
= ovsdb_io_error(retval
, "could not get lock on %s", tmp_name
);
657 /* Remove temporary file. (It might not exist.) */
658 if (unlink(tmp_name
) < 0 && errno
!= ENOENT
) {
659 error
= ovsdb_io_error(errno
, "failed to remove %s", tmp_name
);
664 error
= ovsdb_file_save_copy__(tmp_name
, false, comment
, file
->db
,
670 /* Replace original by temporary. */
671 if (rename(tmp_name
, file
->file_name
)) {
672 error
= ovsdb_io_error(errno
, "failed to rename \"%s\" to \"%s\"",
673 tmp_name
, file
->file_name
);
676 fsync_parent_dir(file
->file_name
);
680 ovsdb_log_close(file
->log
);
682 file
->oldest_commit
= time_msec();
683 file
->next_compact
= file
->oldest_commit
+ COMPACT_MIN_MSEC
;
684 file
->n_transactions
= 1;
686 ovsdb_log_close(new_log
);
692 lockfile_unlock(tmp_lock
);
700 ovsdb_file_destroy(struct ovsdb_replica
*replica
)
702 struct ovsdb_file
*file
= ovsdb_file_cast(replica
);
704 ovsdb_log_close(file
->log
);
705 free(file
->file_name
);
709 static const struct ovsdb_replica_class ovsdb_file_class
= {
715 ovsdb_file_txn_init(struct ovsdb_file_txn
*ftxn
)
718 ftxn
->table_json
= NULL
;
723 ovsdb_file_txn_add_row(struct ovsdb_file_txn
*ftxn
,
724 const struct ovsdb_row
*old
,
725 const struct ovsdb_row
*new,
726 const unsigned long int *changed
)
731 row
= json_null_create();
733 struct shash_node
*node
;
735 row
= old
? NULL
: json_object_create();
736 SHASH_FOR_EACH (node
, &new->table
->schema
->columns
) {
737 const struct ovsdb_column
*column
= node
->data
;
738 const struct ovsdb_type
*type
= &column
->type
;
739 unsigned int idx
= column
->index
;
741 if (idx
!= OVSDB_COL_UUID
&& column
->persistent
743 ? bitmap_is_set(changed
, idx
)
744 : !ovsdb_datum_is_default(&new->fields
[idx
], type
)))
747 row
= json_object_create();
749 json_object_put(row
, column
->name
,
750 ovsdb_datum_to_json(&new->fields
[idx
], type
));
756 struct ovsdb_table
*table
= new ? new->table
: old
->table
;
757 char uuid
[UUID_LEN
+ 1];
759 if (table
!= ftxn
->table
) {
760 /* Create JSON object for transaction overall. */
762 ftxn
->json
= json_object_create();
765 /* Create JSON object for transaction on this table. */
766 ftxn
->table_json
= json_object_create();
768 json_object_put(ftxn
->json
, table
->schema
->name
, ftxn
->table_json
);
771 /* Add row to transaction for this table. */
772 snprintf(uuid
, sizeof uuid
,
773 UUID_FMT
, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old
)));
774 json_object_put(ftxn
->table_json
, uuid
, row
);
778 static struct ovsdb_error
*
779 ovsdb_file_txn_commit(struct json
*json
, const char *comment
,
780 bool durable
, struct ovsdb_log
*log
)
782 struct ovsdb_error
*error
;
785 json
= json_object_create();
788 json_object_put_string(json
, "_comment", comment
);
790 json_object_put(json
, "_date", json_integer_create(time_wall()));
792 error
= ovsdb_log_write(log
, json
);
795 return ovsdb_wrap_error(error
, "writing transaction failed");
799 error
= ovsdb_log_commit(log
);
801 return ovsdb_wrap_error(error
, "committing transaction failed");