Fix: add missing buffer registry cleanup on error

Fixes #542

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: remove one too many metadata refcount increment

The refcount increment is removed from the add metadata stream function
so for both kernel and UST, the increment is done once the stream is
allocated and the channel reference is set.

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: skip metadata flushed check if write failed

On a metadata cache write failure, we now skip the metadata flushed
check or else an infinite loop could have been possible.

Acked-by: Julien Desfossez <julien.desfossez@efficios.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: set metadata closed on a push/close metadata error

Check the metadata closed flag before pushing and closing the metadata
on the consumer side. On any error from those two actions, the closed
flag is set to indicate to stop using the metadata registry until a
destroy is done.

Also, before creating a metadata, a check is done to see if the registry
metadata was closed previously or else a new metadata key is created and
the old values from the previous channel in the registry are used
causing a bad state on the consumer.

With per UID buffers, the metadata cache is shared accross multiple
applications so if the metadata buffers were deleted on the consumer for
whatever reasons, we must STOP using it or else undesired behaviors have
been observed such as causing synchronization issues between the state
of the consumer and sessiond.

A destroy session command will wipe the faulty metadata.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: add more conditions and a lock to metadata cache flushed

Some more conditions applies to return if the metadata cache is indeed
flushed. If no metadata stream is found or the endpoint status is set to
something other than ACTIVE, this means the channel is being (or will
be) destroyed thus the metadata cache can't be updated so is indeed
"flushed".

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
Revert "Improve channel listing output format"

This changed the text output *after* rc1. We'll keep this in the back
burner for 2.3.

This reverts commit e78de861055e6288d11348866681d1373ed81aec.
Fix: Missing RCU locks on access to consumerd's channel ht

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: add missing ht iter node assignment in channel thread

Fixes #547

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: remove nonblock flag of sessiond socket in consumer

There is no need for non blocking socket. Furthermore, we have observed
unstable behaviors with a non blocking side (consumer) and a blocking
side (sessiond).

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: poll compat layer reallocation new size

The size was doubled but in fact it should have been checked for the
maximum between the number of fd doubled and the alloc size doubled
(divised by two when shrinking the buffer).

Same goes for the shrink process. For that, get_count_order_u32() is
added to utils.c/.h.

Signed-off-by: David Goulet <dgoulet@efficios.com>
Add a lttng-ctl header to facilitate code separation

In order for lttng-ctl.c not to grow into an uncontrollable monster of
code, add this helper header and remove static declaration of some
functions to be exported out of the C file and set them hidden.

Future work on snapshot and trigger will use it in order to better split
the code into different files.

Signed-off-by: David Goulet <dgoulet@efficios.com>
Move multiple URLs parsing fct from lttng-ctl to uri.c

Just move some functions around so we can use the multiple URLs parsing
to URIs function outside of liblttng-ctl.

Signed-off-by: David Goulet <dgoulet@efficios.com>
Add consumer-stream.c/.h in libconsumer

This new file contains relevant calls to a lttng_consumer_stream object
and for now breaks down consumer_del_stream() in consumer.c that got out
of hand in terms of size and can not be used if the stream was not
previously successfully added to a thread which makes difficult the
deletion of a stream in some error path or in no monitor mode (future
mode for streams with snapshots).

It helps also modularize the consumer object a bit better and makes this
code a bit easier to maintain and to evolve better.

At this commit, no components use this yet. Future work will
incrementaly move every consumer stream specific actions to that file
and of course use those calls.

Signed-off-by: David Goulet <dgoulet@efficios.com>
Use the consumer stream API in consumer_del_stream()

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Snapshot API

Every call has been coded in liblttng-ctl. Nothing on the session daemon
side yet apart from adding the case to the process client command
subsystem.

!!Need comments!! before mergin that commit.

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Add snapshot command to lttng UI

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Snapshot commands in sessiond

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] lttng snapshot command fails if session is not in no output mode

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Flight recorder feature

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Kernel snapshot support

**ADD CHANGELOG**

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>