X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=ovsdb%2Ftransaction.c;h=c07541ed3a049579d4db1325a98f48d8a77120d5;hb=a56104575c4db202bfc5db3079ea969820d77867;hp=218fbce3edd34710422192f14e7966d18c3e99c7;hpb=a0bc29a541fc7dc6e20137d5558e2094d614e6ab;p=openvswitch diff --git a/ovsdb/transaction.c b/ovsdb/transaction.c index 218fbce3..c07541ed 100644 --- a/ovsdb/transaction.c +++ b/ovsdb/transaction.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2009, 2010 Nicira Networks +/* Copyright (c) 2009, 2010, 2011 Nicira Networks * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -57,9 +57,11 @@ struct ovsdb_txn_table { * * - A row modified by a transaction will have non-null 'old' and 'new'. * - * - 'old' and 'new' both null is invalid. It would indicate that a row - * was added then deleted within a single transaction, but we instead - * handle that case by deleting the txn_row entirely. + * - 'old' and 'new' both null indicates that a row was added then deleted + * within a single transaction. Most of the time we instead delete the + * ovsdb_txn_row entirely, but inside a for_each_txn_row() callback + * there are restrictions that sometimes mean we have to leave the + * ovsdb_txn_row in place. */ struct ovsdb_txn_row { struct hmap_node hmap_node; /* In ovsdb_txn_table's txn_rows hmap. */ @@ -67,12 +69,20 @@ struct ovsdb_txn_row { struct ovsdb_row *new; /* The new row. */ size_t n_refs; /* Number of remaining references. */ + /* These members are the same as the corresponding members of 'old' or + * 'new'. They are present here for convenience and because occasionally + * there can be an ovsdb_txn_row where both 'old' and 'new' are NULL. */ + struct uuid uuid; + struct ovsdb_table *table; + /* Used by for_each_txn_row(). */ unsigned int serial; /* Serial number of in-progress commit. */ unsigned long changed[]; /* Bits set to 1 for columns that changed. */ }; +static struct ovsdb_error * WARN_UNUSED_RESULT +delete_garbage_row(struct ovsdb_txn *txn, struct ovsdb_txn_row *r); static void ovsdb_txn_row_prefree(struct ovsdb_txn_row *); static struct ovsdb_error * WARN_UNUSED_RESULT for_each_txn_row(struct ovsdb_txn *txn, @@ -110,7 +120,9 @@ ovsdb_txn_row_abort(struct ovsdb_txn *txn OVS_UNUSED, ovsdb_txn_row_prefree(txn_row); if (!old) { - hmap_remove(&new->table->rows, &new->hmap_node); + if (new) { + hmap_remove(&new->table->rows, &new->hmap_node); + } } else if (!new) { hmap_insert(&old->table->rows, &old->hmap_node, ovsdb_row_hash(old)); } else { @@ -138,12 +150,9 @@ find_txn_row(const struct ovsdb_table *table, const struct uuid *uuid) return NULL; } - HMAP_FOR_EACH_WITH_HASH (txn_row, struct ovsdb_txn_row, hmap_node, + HMAP_FOR_EACH_WITH_HASH (txn_row, hmap_node, uuid_hash(uuid), &table->txn_table->txn_rows) { - const struct ovsdb_row *row; - - row = txn_row->old ? txn_row->old : txn_row->new; - if (uuid_equals(uuid, ovsdb_row_get_uuid(row))) { + if (uuid_equals(uuid, &txn_row->uuid)) { return txn_row; } } @@ -151,8 +160,23 @@ find_txn_row(const struct ovsdb_table *table, const struct uuid *uuid) return NULL; } +static struct ovsdb_txn_row * +find_or_make_txn_row(struct ovsdb_txn *txn, const struct ovsdb_table *table, + const struct uuid *uuid) +{ + struct ovsdb_txn_row *txn_row = find_txn_row(table, uuid); + if (!txn_row) { + const struct ovsdb_row *row = ovsdb_table_get_row(table, uuid); + if (row) { + txn_row = ovsdb_txn_row_modify(txn, row)->txn_row; + } + } + return txn_row; +} + static struct ovsdb_error * WARN_UNUSED_RESULT -ovsdb_txn_adjust_atom_refs(struct ovsdb_txn *txn, +ovsdb_txn_adjust_atom_refs(struct ovsdb_txn *txn, const struct ovsdb_row *r, + const struct ovsdb_column *c, const struct ovsdb_base_type *base, const union ovsdb_atom *atoms, unsigned int n, int delta) @@ -167,16 +191,22 @@ ovsdb_txn_adjust_atom_refs(struct ovsdb_txn *txn, table = base->u.uuid.refTable; for (i = 0; i < n; i++) { const struct uuid *uuid = &atoms[i].uuid; - struct ovsdb_txn_row *txn_row = find_txn_row(table, uuid); + struct ovsdb_txn_row *txn_row; + + if (uuid_equals(uuid, ovsdb_row_get_uuid(r))) { + /* Self-references don't count. */ + continue; + } + + txn_row = find_or_make_txn_row(txn, table, uuid); if (!txn_row) { - const struct ovsdb_row *row = ovsdb_table_get_row(table, uuid); - if (row) { - txn_row = ovsdb_txn_row_modify(txn, row)->txn_row; - } else { - return ovsdb_error("referential integrity violation", - "reference to nonexistent row " - UUID_FMT, UUID_ARGS(uuid)); - } + return ovsdb_error("referential integrity violation", + "Table %s column %s row "UUID_FMT" " + "references nonexistent row "UUID_FMT" in " + "table %s.", + r->table->schema->name, c->name, + UUID_ARGS(ovsdb_row_get_uuid(r)), + UUID_ARGS(uuid), table->schema->name); } txn_row->n_refs += delta; } @@ -191,10 +221,10 @@ ovsdb_txn_adjust_row_refs(struct ovsdb_txn *txn, const struct ovsdb_row *r, const struct ovsdb_datum *field = &r->fields[column->index]; struct ovsdb_error *error; - error = ovsdb_txn_adjust_atom_refs(txn, &column->type.key, + error = ovsdb_txn_adjust_atom_refs(txn, r, column, &column->type.key, field->keys, field->n, delta); if (!error) { - error = ovsdb_txn_adjust_atom_refs(txn, &column->type.value, + error = ovsdb_txn_adjust_atom_refs(txn, r, column, &column->type.value, field->values, field->n, delta); } return error; @@ -203,7 +233,7 @@ ovsdb_txn_adjust_row_refs(struct ovsdb_txn *txn, const struct ovsdb_row *r, static struct ovsdb_error * WARN_UNUSED_RESULT update_row_ref_count(struct ovsdb_txn *txn, struct ovsdb_txn_row *r) { - struct ovsdb_table *table = r->old ? r->old->table : r->new->table; + struct ovsdb_table *table = r->table; struct shash_node *node; SHASH_FOR_EACH (node, &table->schema->columns) { @@ -213,8 +243,7 @@ update_row_ref_count(struct ovsdb_txn *txn, struct ovsdb_txn_row *r) if (r->old) { error = ovsdb_txn_adjust_row_refs(txn, r->old, column, -1); if (error) { - ovsdb_error_destroy(error); - return OVSDB_BUG("error decreasing refcount"); + return OVSDB_WRAP_BUG("error decreasing refcount", error); } } if (r->new) { @@ -237,12 +266,97 @@ check_ref_count(struct ovsdb_txn *txn OVS_UNUSED, struct ovsdb_txn_row *r) return ovsdb_error("referential integrity violation", "cannot delete %s row "UUID_FMT" because " "of %zu remaining reference(s)", - r->old->table->schema->name, - UUID_ARGS(ovsdb_row_get_uuid(r->old)), + r->table->schema->name, UUID_ARGS(&r->uuid), r->n_refs); } } +static struct ovsdb_error * WARN_UNUSED_RESULT +delete_row_refs(struct ovsdb_txn *txn, const struct ovsdb_row *row, + const struct ovsdb_base_type *base, + const union ovsdb_atom *atoms, unsigned int n) +{ + const struct ovsdb_table *table; + unsigned int i; + + if (!ovsdb_base_type_is_strong_ref(base)) { + return NULL; + } + + table = base->u.uuid.refTable; + for (i = 0; i < n; i++) { + const struct uuid *uuid = &atoms[i].uuid; + struct ovsdb_txn_row *txn_row; + + if (uuid_equals(uuid, ovsdb_row_get_uuid(row))) { + /* Self-references don't count. */ + continue; + } + + txn_row = find_or_make_txn_row(txn, table, uuid); + if (!txn_row) { + return OVSDB_BUG("strong ref target missing"); + } else if (!txn_row->n_refs) { + return OVSDB_BUG("strong ref target has zero n_refs"); + } else if (!txn_row->new) { + return OVSDB_BUG("deleted strong ref target"); + } + + if (--txn_row->n_refs == 0) { + struct ovsdb_error *error = delete_garbage_row(txn, txn_row); + if (error) { + return error; + } + } + } + + return NULL; +} + +static struct ovsdb_error * WARN_UNUSED_RESULT +delete_garbage_row(struct ovsdb_txn *txn, struct ovsdb_txn_row *txn_row) +{ + struct shash_node *node; + struct ovsdb_row *row; + + if (txn_row->table->schema->is_root) { + return NULL; + } + + row = txn_row->new; + txn_row->new = NULL; + hmap_remove(&txn_row->table->rows, &row->hmap_node); + SHASH_FOR_EACH (node, &txn_row->table->schema->columns) { + const struct ovsdb_column *column = node->data; + const struct ovsdb_datum *field = &row->fields[column->index]; + struct ovsdb_error *error; + + error = delete_row_refs(txn, row, + &column->type.key, field->keys, field->n); + if (error) { + return error; + } + + error = delete_row_refs(txn, row, + &column->type.value, field->values, field->n); + if (error) { + return error; + } + } + ovsdb_row_destroy(row); + + return NULL; +} + +static struct ovsdb_error * WARN_UNUSED_RESULT +collect_garbage(struct ovsdb_txn *txn, struct ovsdb_txn_row *txn_row) +{ + if (txn_row->new && !txn_row->n_refs) { + return delete_garbage_row(txn, txn_row); + } + return NULL; +} + static struct ovsdb_error * WARN_UNUSED_RESULT update_ref_counts(struct ovsdb_txn *txn) { @@ -310,8 +424,7 @@ assess_weak_refs(struct ovsdb_txn *txn, struct ovsdb_txn_row *txn_row) * that their weak references will get reassessed. */ struct ovsdb_weak_ref *weak, *next; - LIST_FOR_EACH_SAFE (weak, next, struct ovsdb_weak_ref, dst_node, - &txn_row->old->dst_refs) { + LIST_FOR_EACH_SAFE (weak, next, dst_node, &txn_row->old->dst_refs) { if (!weak->src->txn_row) { ovsdb_txn_row_modify(txn, weak->src); } @@ -325,7 +438,7 @@ assess_weak_refs(struct ovsdb_txn *txn, struct ovsdb_txn_row *txn_row) return NULL; } - table = txn_row->new->table; + table = txn_row->table; SHASH_FOR_EACH (node, &table->schema->columns) { const struct ovsdb_column *column = node->data; struct ovsdb_datum *datum = &txn_row->new->fields[column->index]; @@ -409,9 +522,8 @@ assess_weak_refs(struct ovsdb_txn *txn, struct ovsdb_txn_row *txn_row) static struct ovsdb_error * WARN_UNUSED_RESULT determine_changes(struct ovsdb_txn *txn, struct ovsdb_txn_row *txn_row) { - struct ovsdb_table *table; + struct ovsdb_table *table = txn_row->table; - table = (txn_row->old ? txn_row->old : txn_row->new)->table; if (txn_row->old && txn_row->new) { struct shash_node *node; bool changed = false; @@ -446,7 +558,7 @@ check_max_rows(struct ovsdb_txn *txn) { struct ovsdb_txn_table *t; - LIST_FOR_EACH (t, struct ovsdb_txn_table, node, &txn->txn_tables) { + LIST_FOR_EACH (t, node, &txn->txn_tables) { size_t n_rows = hmap_count(&t->table->rows); unsigned int max_rows = t->table->schema->max_rows; @@ -472,23 +584,29 @@ ovsdb_txn_commit(struct ovsdb_txn *txn, bool durable) * was really a no-op. */ error = for_each_txn_row(txn, determine_changes); if (error) { - ovsdb_error_destroy(error); - return OVSDB_BUG("can't happen"); + return OVSDB_WRAP_BUG("can't happen", error); } if (list_is_empty(&txn->txn_tables)) { ovsdb_txn_abort(txn); return NULL; } - /* Check maximum rows table constraints. */ - error = check_max_rows(txn); + /* Update reference counts and check referential integrity. */ + error = update_ref_counts(txn); if (error) { ovsdb_txn_abort(txn); return error; } - /* Update reference counts and check referential integrity. */ - error = update_ref_counts(txn); + /* Delete unreferenced, non-root rows. */ + error = for_each_txn_row(txn, collect_garbage); + if (error) { + ovsdb_txn_abort(txn); + return OVSDB_WRAP_BUG("can't happen", error); + } + + /* Check maximum rows table constraints. */ + error = check_max_rows(txn); if (error) { ovsdb_txn_abort(txn); return error; @@ -503,7 +621,7 @@ ovsdb_txn_commit(struct ovsdb_txn *txn, bool durable) } /* Send the commit to each replica. */ - LIST_FOR_EACH (replica, struct ovsdb_replica, node, &txn->db->replicas) { + LIST_FOR_EACH (replica, node, &txn->db->replicas) { error = (replica->class->commit)(replica, txn, durable); if (error) { /* We don't support two-phase commit so only the first replica is @@ -530,9 +648,9 @@ ovsdb_txn_for_each_change(const struct ovsdb_txn *txn, struct ovsdb_txn_table *t; struct ovsdb_txn_row *r; - LIST_FOR_EACH (t, struct ovsdb_txn_table, node, &txn->txn_tables) { - HMAP_FOR_EACH (r, struct ovsdb_txn_row, hmap_node, &t->txn_rows) { - if (!cb(r->old, r->new, r->changed, aux)) { + LIST_FOR_EACH (t, node, &txn->txn_tables) { + HMAP_FOR_EACH (r, hmap_node, &t->txn_rows) { + if ((r->old || r->new) && !cb(r->old, r->new, r->changed, aux)) { break; } } @@ -558,6 +676,7 @@ static struct ovsdb_txn_row * ovsdb_txn_row_create(struct ovsdb_txn *txn, struct ovsdb_table *table, const struct ovsdb_row *old_, struct ovsdb_row *new) { + const struct ovsdb_row *row = old_ ? old_ : new; struct ovsdb_row *old = (struct ovsdb_row *) old_; size_t n_columns = shash_count(&table->schema->columns); struct ovsdb_txn_table *txn_table; @@ -565,7 +684,9 @@ ovsdb_txn_row_create(struct ovsdb_txn *txn, struct ovsdb_table *table, txn_row = xzalloc(offsetof(struct ovsdb_txn_row, changed) + bitmap_n_bytes(n_columns)); - txn_row->old = (struct ovsdb_row *) old; + txn_row->uuid = *ovsdb_row_get_uuid(row); + txn_row->table = row->table; + txn_row->old = old; txn_row->new = new; txn_row->n_refs = old ? old->n_refs : 0; txn_row->serial = serial - 1; @@ -661,8 +782,7 @@ ovsdb_txn_get_comment(const struct ovsdb_txn *txn) static void ovsdb_txn_row_prefree(struct ovsdb_txn_row *txn_row) { - struct ovsdb_row *row = txn_row->old ? txn_row->old : txn_row->new; - struct ovsdb_txn_table *txn_table = row->table->txn_table; + struct ovsdb_txn_table *txn_table = txn_row->table->txn_table; txn_table->n_processed--; hmap_remove(&txn_table->txn_rows, &txn_row->hmap_node); @@ -695,6 +815,9 @@ ovsdb_txn_table_destroy(struct ovsdb_txn_table *txn_table) * in within the same txn_table. It may *not* delete any txn_tables. As long * as these rules are followed, 'cb' will be called exactly once for each * txn_row in 'txn', even those added by 'cb'. + * + * (Even though 'cb' is not allowed to delete some txn_rows, it can still + * delete any actual row by clearing a txn_row's 'new' member.) */ static struct ovsdb_error * WARN_UNUSED_RESULT for_each_txn_row(struct ovsdb_txn *txn, @@ -709,8 +832,7 @@ for_each_txn_row(struct ovsdb_txn *txn, struct ovsdb_txn_table *t, *next_txn_table; any_work = false; - LIST_FOR_EACH_SAFE (t, next_txn_table, struct ovsdb_txn_table, node, - &txn->txn_tables) { + LIST_FOR_EACH_SAFE (t, next_txn_table, node, &txn->txn_tables) { if (t->serial != serial) { t->serial = serial; t->n_processed = 0; @@ -719,9 +841,7 @@ for_each_txn_row(struct ovsdb_txn *txn, while (t->n_processed < hmap_count(&t->txn_rows)) { struct ovsdb_txn_row *r, *next_txn_row; - HMAP_FOR_EACH_SAFE (r, next_txn_row, - struct ovsdb_txn_row, hmap_node, - &t->txn_rows) { + HMAP_FOR_EACH_SAFE (r, next_txn_row, hmap_node, &t->txn_rows) { if (r->serial != serial) { struct ovsdb_error *error;