[lttng-tools.git] / src / bin / lttng-sessiond / channel.c

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _GNU_SOURCE
#include <inttypes.h>
#include <string.h>
#include <unistd.h>

#include <common/common.h>
#include <common/defaults.h>
#include <common/sessiond-comm/sessiond-comm.h>

#include "channel.h"
#include "kernel.h"
#include "ust-ctl.h"
#include "utils.h"
#include "ust-app.h"

/*
 * Return allocated channel attributes.
 */
struct lttng_channel *channel_new_default_attr(int dom,
		enum lttng_buffer_type type)
{
	struct lttng_channel *chan;

	chan = zmalloc(sizeof(struct lttng_channel));
	if (chan == NULL) {
		PERROR("zmalloc channel init");
		goto error_alloc;
	}

	if (snprintf(chan->name, sizeof(chan->name), "%s",
				DEFAULT_CHANNEL_NAME) < 0) {
		PERROR("snprintf default channel name");
		goto error;
	}

	/* Same for all domains. */
	chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
	chan->attr.tracefile_size = DEFAULT_CHANNEL_TRACEFILE_SIZE;
	chan->attr.tracefile_count = DEFAULT_CHANNEL_TRACEFILE_COUNT;

	switch (dom) {
	case LTTNG_DOMAIN_KERNEL:
		assert(type == LTTNG_BUFFER_GLOBAL);
		chan->attr.subbuf_size =
			default_get_kernel_channel_subbuf_size();
		chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
		chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
		chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
		chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
		break;
	case LTTNG_DOMAIN_UST:
		switch (type) {
		case LTTNG_BUFFER_PER_UID:
			chan->attr.subbuf_size = default_get_ust_uid_channel_subbuf_size();
			chan->attr.num_subbuf = DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM;
			chan->attr.output = DEFAULT_UST_UID_CHANNEL_OUTPUT;
			chan->attr.switch_timer_interval =
				DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER;
			chan->attr.read_timer_interval =
				DEFAULT_UST_UID_CHANNEL_READ_TIMER;
			break;
		case LTTNG_BUFFER_PER_PID:
		default:
			chan->attr.subbuf_size = default_get_ust_pid_channel_subbuf_size();
			chan->attr.num_subbuf = DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM;
			chan->attr.output = DEFAULT_UST_PID_CHANNEL_OUTPUT;
			chan->attr.switch_timer_interval =
				DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER;
			chan->attr.read_timer_interval =
				DEFAULT_UST_PID_CHANNEL_READ_TIMER;
			break;
		}
		break;
	default:
		goto error;	/* Not implemented */
	}

	return chan;

error:
	free(chan);
error_alloc:
	return NULL;
}

/*
 * Disable kernel channel of the kernel session.
 */
int channel_kernel_disable(struct ltt_kernel_session *ksession,
		char *channel_name)
{
	int ret;
	struct ltt_kernel_channel *kchan;

	assert(ksession);
	assert(channel_name);

	kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
	if (kchan == NULL) {
		ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
		goto error;
	}

	/* Only if channel is enabled disable it. */
	if (kchan->enabled == 1) {
		ret = kernel_disable_channel(kchan);
		if (ret < 0 && ret != -EEXIST) {
			ret = LTTNG_ERR_KERN_CHAN_DISABLE_FAIL;
			goto error;
		}
	}

	ret = LTTNG_OK;

error:
	return ret;
}

/*
 * Enable kernel channel of the kernel session.
 */
int channel_kernel_enable(struct ltt_kernel_session *ksession,
		struct ltt_kernel_channel *kchan)
{
	int ret;

	assert(ksession);
	assert(kchan);

	if (kchan->enabled == 0) {
		ret = kernel_enable_channel(kchan);
		if (ret < 0) {
			ret = LTTNG_ERR_KERN_CHAN_ENABLE_FAIL;
			goto error;
		}
	} else {
		ret = LTTNG_ERR_KERN_CHAN_EXIST;
		goto error;
	}

	ret = LTTNG_OK;

error:
	return ret;
}

/*
 * Create kernel channel of the kernel session and notify kernel thread.
 */
int channel_kernel_create(struct ltt_kernel_session *ksession,
		struct lttng_channel *attr, int kernel_pipe)
{
	int ret;
	struct lttng_channel *defattr = NULL;

	assert(ksession);

	/* Creating channel attributes if needed */
	if (attr == NULL) {
		defattr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
				LTTNG_BUFFER_GLOBAL);
		if (defattr == NULL) {
			ret = LTTNG_ERR_FATAL;
			goto error;
		}
		attr = defattr;
	}

	/* Channel not found, creating it */
	ret = kernel_create_channel(ksession, attr);
	if (ret < 0) {
		ret = LTTNG_ERR_KERN_CHAN_FAIL;
		goto error;
	}

	/* Notify kernel thread that there is a new channel */
	ret = notify_thread_pipe(kernel_pipe);
	if (ret < 0) {
		ret = LTTNG_ERR_FATAL;
		goto error;
	}

	ret = LTTNG_OK;
error:
	free(defattr);
	return ret;
}

/*
 * Enable UST channel for session and domain.
 */
int channel_ust_enable(struct ltt_ust_session *usess,
		struct ltt_ust_channel *uchan)
{
	int ret = LTTNG_OK;

	assert(usess);
	assert(uchan);

	/* If already enabled, everything is OK */
	if (uchan->enabled) {
		DBG3("Channel %s already enabled. Skipping", uchan->name);
		ret = LTTNG_ERR_UST_CHAN_EXIST;
		goto end;
	}

	DBG2("Channel %s being enabled in UST domain", uchan->name);

	/*
	 * Enable channel for UST global domain on all applications. Ignore return
	 * value here since whatever error we got, it means that the channel was
	 * not created on one or many registered applications and we can not report
	 * this to the user yet. However, at this stage, the channel was
	 * successfully created on the session daemon side so the enable-channel
	 * command is a success.
	 */
	(void) ust_app_enable_channel_glb(usess, uchan);

	uchan->enabled = 1;
	DBG2("Channel %s enabled successfully", uchan->name);

end:
	return ret;
}

/*
 * Create UST channel for session and domain.
 */
int channel_ust_create(struct ltt_ust_session *usess,
		struct lttng_channel *attr, enum lttng_buffer_type type)
{
	int ret = LTTNG_OK;
	struct ltt_ust_channel *uchan = NULL;
	struct lttng_channel *defattr = NULL;

	assert(usess);

	/* Creating channel attributes if needed */
	if (attr == NULL) {
		defattr = channel_new_default_attr(LTTNG_DOMAIN_UST, type);
		if (defattr == NULL) {
			ret = LTTNG_ERR_FATAL;
			goto error;
		}
		attr = defattr;
	}

	/*
	 * Validate UST buffer size and number of buffers: must both be power of 2
	 * and nonzero. We validate right here for UST, because applications will
	 * not report the error to the user (unlike kernel tracing).
	 */
	if (!attr->attr.subbuf_size ||
			(attr->attr.subbuf_size & (attr->attr.subbuf_size - 1))) {
		ret = LTTNG_ERR_INVALID;
		goto error;
	}

	if (!attr->attr.num_subbuf ||
			(attr->attr.num_subbuf & (attr->attr.num_subbuf - 1))) {
		ret = LTTNG_ERR_INVALID;
		goto error;
	}

	if (attr->attr.output != LTTNG_EVENT_MMAP) {
		ret = LTTNG_ERR_NOT_SUPPORTED;
		goto error;
	}

	/*
	 * The tracefile_size should not be < to the subbuf_size, otherwise
	 * we won't be able to write the packets on disk
	 */
	if ((attr->attr.tracefile_size > 0) &&
			(attr->attr.tracefile_size < attr->attr.subbuf_size)) {
		ret = LTTNG_ERR_INVALID;
		goto error;
	}

	/* Validate buffer type. */
	switch (type) {
	case LTTNG_BUFFER_PER_PID:
		if (attr->attr.subbuf_size <
				default_get_ust_pid_channel_subbuf_size()) {
			ret = LTTNG_ERR_INVALID;
			goto error;
		}
		break;
	case LTTNG_BUFFER_PER_UID:
		if (attr->attr.subbuf_size <
				default_get_ust_uid_channel_subbuf_size()) {
			ret = LTTNG_ERR_INVALID;
			goto error;
		}
		break;
	default:
		ret = LTTNG_ERR_BUFFER_NOT_SUPPORTED;
		goto error;
	}

	/* Create UST channel */
	uchan = trace_ust_create_channel(attr);
	if (uchan == NULL) {
		ret = LTTNG_ERR_FATAL;
		goto error;
	}
	uchan->enabled = 1;
	if (trace_ust_is_max_id(usess->used_channel_id)) {
		ret = LTTNG_ERR_UST_CHAN_FAIL;
		goto error;
	}
	uchan->id = trace_ust_get_next_chan_id(usess);

	DBG2("Channel %s is being created for UST with buffer %d and id %" PRIu64,
			uchan->name, type, uchan->id);

	/* Flag session buffer type. */
	if (!usess->buffer_type_changed) {
		usess->buffer_type = type;
		usess->buffer_type_changed = 1;
	} else if (usess->buffer_type != type) {
		/* Buffer type was already set. Refuse to create channel. */
		ret = LTTNG_ERR_BUFFER_TYPE_MISMATCH;
		goto error_free_chan;
	}

	/* Enable channel for global domain */
	ret = ust_app_create_channel_glb(usess, uchan);
	if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
		ret = LTTNG_ERR_UST_CHAN_FAIL;
		goto error_free_chan;
	}

	/* Adding the channel to the channel hash table. */
	rcu_read_lock();
	lttng_ht_add_unique_str(usess->domain_global.channels, &uchan->node);
	rcu_read_unlock();

	DBG2("Channel %s created successfully", uchan->name);

	free(defattr);
	return LTTNG_OK;

error_free_chan:
	/*
	 * No need to remove the channel from the hash table because at this point
	 * it was not added hence the direct call and no call_rcu().
	 */
	trace_ust_destroy_channel(uchan);
error:
	free(defattr);
	return ret;
}

/*
 * Disable UST channel for session and domain.
 */
int channel_ust_disable(struct ltt_ust_session *usess,
		struct ltt_ust_channel *uchan)
{
	int ret = LTTNG_OK;

	assert(usess);
	assert(uchan);

	/* Already disabled */
	if (uchan->enabled == 0) {
		DBG2("Channel UST %s already disabled", uchan->name);
		goto end;
	}

	DBG2("Channel %s being disabled in UST global domain", uchan->name);
	/* Disable channel for global domain */
	ret = ust_app_disable_channel_glb(usess, uchan);
	if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
		ret = LTTNG_ERR_UST_CHAN_DISABLE_FAIL;
		goto error;
	}

	uchan->enabled = 0;

	DBG2("Channel %s disabled successfully", uchan->name);

	return LTTNG_OK;

end:
error:
	return ret;
}
Commit	Line	Data
54d01ffb DG	1	/*
	2	* Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
	3	*
d14d33bf AM	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License, version 2 only,
	6	* as published by the Free Software Foundation.
54d01ffb	7	*
d14d33bf AM	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	* GNU General Public License for more details.
54d01ffb	12	*
d14d33bf AM	13	* You should have received a copy of the GNU General Public License along
	14	* with this program; if not, write to the Free Software Foundation, Inc.,
	15	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
54d01ffb DG	16	*/
54d01ffb DG	17
7885e399	18	#define _GNU_SOURCE
7972aab2	19	#include <inttypes.h>
56fff090	20	#include <string.h>
54d01ffb DG	21	#include <unistd.h>
54d01ffb DG	22
990570ed DG	23	#include <common/common.h>
990570ed DG	24	#include <common/defaults.h>
db758600	25	#include <common/sessiond-comm/sessiond-comm.h>
54d01ffb DG	26
54d01ffb DG	27	#include "channel.h"
4771f025	28	#include "kernel.h"
44d3bd01	29	#include "ust-ctl.h"
54d01ffb	30	#include "utils.h"
7885e399	31	#include "ust-app.h"
54d01ffb DG	32
	33	/*
	34	* Return allocated channel attributes.
	35	*/
0a9c6494 DG	36	struct lttng_channel *channel_new_default_attr(int dom,
0a9c6494 DG	37	enum lttng_buffer_type type)
54d01ffb DG	38	{
	39	struct lttng_channel *chan;
	40
	41	chan = zmalloc(sizeof(struct lttng_channel));
	42	if (chan == NULL) {
7885e399	43	PERROR("zmalloc channel init");
54d01ffb DG	44	goto error_alloc;
	45	}
	46
44d3bd01 DG	47	if (snprintf(chan->name, sizeof(chan->name), "%s",
44d3bd01 DG	48	DEFAULT_CHANNEL_NAME) < 0) {
7885e399	49	PERROR("snprintf default channel name");
54d01ffb DG	50	goto error;
	51	}
	52
0a9c6494	53	/* Same for all domains. */
54d01ffb	54	chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
0a9c6494 DG	55	chan->attr.tracefile_size = DEFAULT_CHANNEL_TRACEFILE_SIZE;
0a9c6494 DG	56	chan->attr.tracefile_count = DEFAULT_CHANNEL_TRACEFILE_COUNT;
54d01ffb DG	57
54d01ffb DG	58	switch (dom) {
1b1c65fa	59	case LTTNG_DOMAIN_KERNEL:
0a9c6494	60	assert(type == LTTNG_BUFFER_GLOBAL);
3e230f92 SM	61	chan->attr.subbuf_size =
3e230f92 SM	62	default_get_kernel_channel_subbuf_size();
1b1c65fa MD	63	chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
1b1c65fa MD	64	chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
6bb9e85f MD	65	chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
6bb9e85f MD	66	chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
1b1c65fa MD	67	break;
1b1c65fa MD	68	case LTTNG_DOMAIN_UST:
0a9c6494 DG	69	switch (type) {
	70	case LTTNG_BUFFER_PER_UID:
	71	chan->attr.subbuf_size = default_get_ust_uid_channel_subbuf_size();
	72	chan->attr.num_subbuf = DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM;
	73	chan->attr.output = DEFAULT_UST_UID_CHANNEL_OUTPUT;
	74	chan->attr.switch_timer_interval =
	75	DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER;
	76	chan->attr.read_timer_interval =
	77	DEFAULT_UST_UID_CHANNEL_READ_TIMER;
	78	break;
	79	case LTTNG_BUFFER_PER_PID:
	80	default:
	81	chan->attr.subbuf_size = default_get_ust_pid_channel_subbuf_size();
	82	chan->attr.num_subbuf = DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM;
	83	chan->attr.output = DEFAULT_UST_PID_CHANNEL_OUTPUT;
	84	chan->attr.switch_timer_interval =
	85	DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER;
	86	chan->attr.read_timer_interval =
	87	DEFAULT_UST_PID_CHANNEL_READ_TIMER;
	88	break;
	89	}
1b1c65fa MD	90	break;
	91	default:
	92	goto error; /* Not implemented */
54d01ffb DG	93	}
	94
	95	return chan;
	96
	97	error:
	98	free(chan);
	99	error_alloc:
	100	return NULL;
	101	}
	102
	103	/*
	104	* Disable kernel channel of the kernel session.
	105	*/
	106	int channel_kernel_disable(struct ltt_kernel_session *ksession,
	107	char *channel_name)
	108	{
	109	int ret;
	110	struct ltt_kernel_channel *kchan;
	111
0525e9ae DG	112	assert(ksession);
	113	assert(channel_name);
	114
54d01ffb DG	115	kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
54d01ffb DG	116	if (kchan == NULL) {
f73fabfd	117	ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
54d01ffb	118	goto error;
0525e9ae DG	119	}
	120
	121	/* Only if channel is enabled disable it. */
	122	if (kchan->enabled == 1) {
54d01ffb	123	ret = kernel_disable_channel(kchan);
7885e399	124	if (ret < 0 && ret != -EEXIST) {
f73fabfd	125	ret = LTTNG_ERR_KERN_CHAN_DISABLE_FAIL;
54d01ffb DG	126	goto error;
	127	}
	128	}
	129
f73fabfd	130	ret = LTTNG_OK;
54d01ffb DG	131
	132	error:
	133	return ret;
	134	}
	135
	136	/*
	137	* Enable kernel channel of the kernel session.
	138	*/
	139	int channel_kernel_enable(struct ltt_kernel_session *ksession,
	140	struct ltt_kernel_channel *kchan)
	141	{
	142	int ret;
	143
0525e9ae DG	144	assert(ksession);
	145	assert(kchan);
	146
54d01ffb DG	147	if (kchan->enabled == 0) {
	148	ret = kernel_enable_channel(kchan);
	149	if (ret < 0) {
f73fabfd	150	ret = LTTNG_ERR_KERN_CHAN_ENABLE_FAIL;
54d01ffb DG	151	goto error;
54d01ffb DG	152	}
42224349	153	} else {
f73fabfd	154	ret = LTTNG_ERR_KERN_CHAN_EXIST;
42224349	155	goto error;
54d01ffb DG	156	}
54d01ffb DG	157
f73fabfd	158	ret = LTTNG_OK;
54d01ffb DG	159
	160	error:
	161	return ret;
	162	}
	163
	164	/*
	165	* Create kernel channel of the kernel session and notify kernel thread.
	166	*/
	167	int channel_kernel_create(struct ltt_kernel_session *ksession,
ff4d74e6	168	struct lttng_channel *attr, int kernel_pipe)
54d01ffb DG	169	{
54d01ffb DG	170	int ret;
ff4d74e6	171	struct lttng_channel *defattr = NULL;
54d01ffb	172
0525e9ae DG	173	assert(ksession);
0525e9ae DG	174
54d01ffb DG	175	/* Creating channel attributes if needed */
54d01ffb DG	176	if (attr == NULL) {
0a9c6494 DG	177	defattr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
0a9c6494 DG	178	LTTNG_BUFFER_GLOBAL);
ff4d74e6	179	if (defattr == NULL) {
f73fabfd	180	ret = LTTNG_ERR_FATAL;
54d01ffb DG	181	goto error;
54d01ffb DG	182	}
ff4d74e6	183	attr = defattr;
54d01ffb DG	184	}
	185
	186	/* Channel not found, creating it */
fdd9eb17	187	ret = kernel_create_channel(ksession, attr);
54d01ffb	188	if (ret < 0) {
f73fabfd	189	ret = LTTNG_ERR_KERN_CHAN_FAIL;
54d01ffb DG	190	goto error;
	191	}
	192
	193	/* Notify kernel thread that there is a new channel */
	194	ret = notify_thread_pipe(kernel_pipe);
	195	if (ret < 0) {
f73fabfd	196	ret = LTTNG_ERR_FATAL;
54d01ffb DG	197	goto error;
	198	}
	199
f73fabfd	200	ret = LTTNG_OK;
54d01ffb	201	error:
ff4d74e6	202	free(defattr);
54d01ffb DG	203	return ret;
54d01ffb DG	204	}
7885e399 DG	205
	206	/*
	207	* Enable UST channel for session and domain.
	208	*/
7972aab2	209	int channel_ust_enable(struct ltt_ust_session *usess,
7885e399 DG	210	struct ltt_ust_channel *uchan)
7885e399 DG	211	{
f73fabfd	212	int ret = LTTNG_OK;
7885e399	213
0525e9ae DG	214	assert(usess);
	215	assert(uchan);
	216
7885e399 DG	217	/* If already enabled, everything is OK */
	218	if (uchan->enabled) {
	219	DBG3("Channel %s already enabled. Skipping", uchan->name);
f73fabfd	220	ret = LTTNG_ERR_UST_CHAN_EXIST;
7885e399 DG	221	goto end;
	222	}
	223
7972aab2 DG	224	DBG2("Channel %s being enabled in UST domain", uchan->name);
	225
	226	/*
	227	* Enable channel for UST global domain on all applications. Ignore return
	228	* value here since whatever error we got, it means that the channel was
	229	* not created on one or many registered applications and we can not report
	230	* this to the user yet. However, at this stage, the channel was
	231	* successfully created on the session daemon side so the enable-channel
	232	* command is a success.
	233	*/
d54b4440	234	(void) ust_app_enable_channel_glb(usess, uchan);
7885e399	235
7885e399 DG	236	uchan->enabled = 1;
	237	DBG2("Channel %s enabled successfully", uchan->name);
	238
	239	end:
7885e399 DG	240	return ret;
	241	}
	242
	243	/*
	244	* Create UST channel for session and domain.
	245	*/
7972aab2 DG	246	int channel_ust_create(struct ltt_ust_session *usess,
7972aab2 DG	247	struct lttng_channel *attr, enum lttng_buffer_type type)
7885e399	248	{
f73fabfd	249	int ret = LTTNG_OK;
7885e399 DG	250	struct ltt_ust_channel *uchan = NULL;
	251	struct lttng_channel *defattr = NULL;
	252
0525e9ae DG	253	assert(usess);
0525e9ae DG	254
7885e399 DG	255	/* Creating channel attributes if needed */
7885e399 DG	256	if (attr == NULL) {
0a9c6494	257	defattr = channel_new_default_attr(LTTNG_DOMAIN_UST, type);
7885e399	258	if (defattr == NULL) {
f73fabfd	259	ret = LTTNG_ERR_FATAL;
7885e399 DG	260	goto error;
	261	}
	262	attr = defattr;
	263	}
	264
b024d072	265	/*
0525e9ae DG	266	* Validate UST buffer size and number of buffers: must both be power of 2
	267	* and nonzero. We validate right here for UST, because applications will
	268	* not report the error to the user (unlike kernel tracing).
b024d072	269	*/
0525e9ae DG	270	if (!attr->attr.subbuf_size \|\|
0525e9ae DG	271	(attr->attr.subbuf_size & (attr->attr.subbuf_size - 1))) {
f73fabfd	272	ret = LTTNG_ERR_INVALID;
b024d072 MD	273	goto error;
b024d072 MD	274	}
0525e9ae DG	275
	276	if (!attr->attr.num_subbuf \|\|
	277	(attr->attr.num_subbuf & (attr->attr.num_subbuf - 1))) {
f73fabfd	278	ret = LTTNG_ERR_INVALID;
b024d072 MD	279	goto error;
	280	}
	281
a79d84dd DG	282	if (attr->attr.output != LTTNG_EVENT_MMAP) {
	283	ret = LTTNG_ERR_NOT_SUPPORTED;
	284	goto error;
	285	}
	286
1624d5b7 JD	287	/*
	288	* The tracefile_size should not be < to the subbuf_size, otherwise
	289	* we won't be able to write the packets on disk
	290	*/
	291	if ((attr->attr.tracefile_size > 0) &&
	292	(attr->attr.tracefile_size < attr->attr.subbuf_size)) {
	293	ret = LTTNG_ERR_INVALID;
	294	goto error;
	295	}
	296
2e8269f7 DG	297	/* Validate buffer type. */
	298	switch (type) {
	299	case LTTNG_BUFFER_PER_PID:
0a9c6494 DG	300	if (attr->attr.subbuf_size <
	301	default_get_ust_pid_channel_subbuf_size()) {
	302	ret = LTTNG_ERR_INVALID;
	303	goto error;
	304	}
	305	break;
2e8269f7	306	case LTTNG_BUFFER_PER_UID:
0a9c6494 DG	307	if (attr->attr.subbuf_size <
	308	default_get_ust_uid_channel_subbuf_size()) {
	309	ret = LTTNG_ERR_INVALID;
	310	goto error;
	311	}
2e8269f7 DG	312	break;
	313	default:
	314	ret = LTTNG_ERR_BUFFER_NOT_SUPPORTED;
	315	goto error;
	316	}
	317
7885e399	318	/* Create UST channel */
dec56f6c	319	uchan = trace_ust_create_channel(attr);
7885e399	320	if (uchan == NULL) {
f73fabfd	321	ret = LTTNG_ERR_FATAL;
7885e399 DG	322	goto error;
7885e399 DG	323	}
58f3ca76	324	uchan->enabled = 1;
7972aab2 DG	325	if (trace_ust_is_max_id(usess->used_channel_id)) {
	326	ret = LTTNG_ERR_UST_CHAN_FAIL;
	327	goto error;
	328	}
	329	uchan->id = trace_ust_get_next_chan_id(usess);
	330
	331	DBG2("Channel %s is being created for UST with buffer %d and id %" PRIu64,
	332	uchan->name, type, uchan->id);
	333
	334	/* Flag session buffer type. */
	335	if (!usess->buffer_type_changed) {
	336	usess->buffer_type = type;
	337	usess->buffer_type_changed = 1;
	338	} else if (usess->buffer_type != type) {
	339	/* Buffer type was already set. Refuse to create channel. */
	340	ret = LTTNG_ERR_BUFFER_TYPE_MISMATCH;
7885e399 DG	341	goto error_free_chan;
	342	}
	343
7972aab2 DG	344	/* Enable channel for global domain */
7972aab2 DG	345	ret = ust_app_create_channel_glb(usess, uchan);
49c336c1	346	if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
f73fabfd	347	ret = LTTNG_ERR_UST_CHAN_FAIL;
7885e399 DG	348	goto error_free_chan;
	349	}
	350
fc34caaa DG	351	/* Adding the channel to the channel hash table. */
	352	rcu_read_lock();
	353	lttng_ht_add_unique_str(usess->domain_global.channels, &uchan->node);
	354	rcu_read_unlock();
	355
7885e399 DG	356	DBG2("Channel %s created successfully", uchan->name);
	357
	358	free(defattr);
f73fabfd	359	return LTTNG_OK;
7885e399 DG	360
7885e399 DG	361	error_free_chan:
24d1723f DG	362	/*
	363	* No need to remove the channel from the hash table because at this point
	364	* it was not added hence the direct call and no call_rcu().
	365	*/
7885e399 DG	366	trace_ust_destroy_channel(uchan);
	367	error:
	368	free(defattr);
	369	return ret;
	370	}
	371
	372	/*
	373	* Disable UST channel for session and domain.
	374	*/
7972aab2	375	int channel_ust_disable(struct ltt_ust_session *usess,
7885e399 DG	376	struct ltt_ust_channel *uchan)
7885e399 DG	377	{
f73fabfd	378	int ret = LTTNG_OK;
7885e399	379
0525e9ae DG	380	assert(usess);
	381	assert(uchan);
	382
7885e399 DG	383	/* Already disabled */
	384	if (uchan->enabled == 0) {
	385	DBG2("Channel UST %s already disabled", uchan->name);
	386	goto end;
	387	}
	388
7972aab2 DG	389	DBG2("Channel %s being disabled in UST global domain", uchan->name);
	390	/* Disable channel for global domain */
	391	ret = ust_app_disable_channel_glb(usess, uchan);
49c336c1	392	if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
f73fabfd	393	ret = LTTNG_ERR_UST_CHAN_DISABLE_FAIL;
7885e399 DG	394	goto error;
	395	}
	396
	397	uchan->enabled = 0;
	398
	399	DBG2("Channel %s disabled successfully", uchan->name);
	400
f73fabfd	401	return LTTNG_OK;
7885e399 DG	402
	403	end:
	404	error:
	405	return ret;
	406	}