Until now, ovs-vswitchd has been unable to configure IP addresses and
routes for bridges whose Bridge records lack a Port and an Interface
record for the bridge's local port (e.g. OFPP_LOCAL, the port with the
same name as the bridge itself). When such a bridge was reconfigured,
ovs-vswitchd would output a log message that worried people.
This commit fixes the internal limitation that led to the message being
printed.
Bug #5385.
Until now, by default the IDL replicated all tables and all columns in the
database, and a few functions made it possible to avoid replicating
selected columns. This commit adds a mode in which nothing is replicated
by default and the client code is responsible for specifying each column
and table that it is interested in. The following commit adds a user for
this mode.
ovs-vswitchd has no need to replicate some parts of the database. In
particular, it doesn't need to replicate the bits that it never reads,
such as the external_ids column in the Open_vSwitch table. This saves
some memory, CPU time, and bandwidth to the database.
Another type of column that benefits from special treatment is "write-only
columns", that is, those that ovs-vswitchd writes and keeps up-to-date but
never expects another client to write, such as the cur_cfg column in the
Open_vSwitch table. If the IDL reports that the database has changed when
ovs-vswitchd updates such a column, then ovs-vswitchd reconfigures itself
for no reason, wasting CPU time. This commit also adds support for such
columns.
The existing ovsdb_idl_txn_read() was somewhat difficult and expensive to
use, because it always made a copy of the data in the column. This was
necessary at the time it was introduced, because there was no way for it
to return a "default" value for columns that had not yet been populated
without allocating data and hence requiring the caller to free it.
Now that ovsdb_datum_default() exists, this is no longer required. This
commit introduces a pair of new functions, ovsdb_idl_read() and
ovsdb_idl_get(), that return a pointer to existing data and do not do any
copying. It also transitions all of ovsdb_idl_txn_read()'s callers to
the new interfaces.
This makes it easy to create a bunch of records that are all related to
each other in a single ovs-vsctl invocation. It adds an example to the
ovs-vsctl manpage.
Before OVSDB was adopted in the vswitch, bridge ioctls were synchronous.
That is, an operation that, say, creates a new bridge was guaranteed to
have completed before brcompatd returned a success result to the kernel.
When OVSDB was adopted, however, we failed to maintain this property.
Instead, bridge creation (etc.) only happened some time after the return
value was passed back to the kernel. This causes a race condition against
software that creates or deletes bridges or ports and expects that the
operation is completed synchronously.
This commit restores the synchronous behavior.
Bug #2443.
The ovs-vsctl "create" command, and perhaps other commands, should print
the UUID of the newly created database row, but until now the IDL has not
provided a way to find that out. This commit adds the ability.
ovs-vsctl wants to use these functions directly, so make them available
through the ovsdb-idl public header instead of only through the private
one.
Also, change the prototypes to make them usable without casts.
The IDL is intended to allow clients easier access to data in the database
by providing an extra layer of abstraction. However, ovs-vsctl needs to
also provide generic access to database tables, rows, and columns, and
until now the IDL has not allowed this. In particular, there was no way
to modify the value of a database column by providing a "struct
ovsdb_datum" with the new value and then have that reflected in the IDL
structs, although the other direction was possible.
This commit fixes that problem, which requires a bit of refactoring of the
IDL layer. It also exposes the interface for iterating through table
records to clients directly, by moving it from the "private" IDL header to
the public one.
Until now the ovsdb-based vswitch has provided no way to know when it has
finished applying the configuration from the database. This commit
introduces a way:
* The client who wants to wait increments the "next_cfg" column of the
Open_vSwitch record.
* When ovs-vswitchd finishes reconfiguring, it sets the value of the
"cur_cfg" column to that of the "next_cfg" column.
* The client waits until the "cur_cfg" column is at least as great as
the value it set into "next_cfg".
This allows us to drop the 5-second sleep in interface-reconfigure.
The idea here is that transaction comments get copied to the ovsdb-server's
transaction log, which can then make it clear later why a particular change
was made to the database, to ease debugging.
