[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c

/*
 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
 *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * 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 <assert.h>
#include <poll.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <lttng/ust-ctl.h>

#include <common/common.h>
#include <common/sessiond-comm/sessiond-comm.h>
#include <common/relayd/relayd.h>
#include <common/compat/fcntl.h>

#include "ust-consumer.h"

extern struct lttng_consumer_global_data consumer_data;
extern int consumer_poll_timeout;
extern volatile int consumer_quit;

/*
 * Mmap the ring buffer, read it and write the data to the tracefile.
 *
 * Returns the number of bytes written, else negative value on error.
 */
ssize_t lttng_ustconsumer_on_read_subbuffer_mmap(
		struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream, unsigned long len)
{
	unsigned long mmap_offset;
	long ret = 0, written = 0;
	off_t orig_offset = stream->out_fd_offset;
	int outfd = stream->out_fd;
	uint64_t metadata_id;
	struct consumer_relayd_sock_pair *relayd = NULL;

	/* RCU lock for the relayd pointer */
	rcu_read_lock();

	/* Flag that the current stream if set for network streaming. */
	if (stream->net_seq_idx != -1) {
		relayd = consumer_find_relayd(stream->net_seq_idx);
		if (relayd == NULL) {
			ERR("UST consumer mmap(), unable to find relay for index %d",
					stream->net_seq_idx);
			goto end;
		}
	}

	/* get the offset inside the fd to mmap */
	ret = ustctl_get_mmap_read_offset(stream->chan->handle,
		stream->buf, &mmap_offset);
	if (ret != 0) {
		errno = -ret;
		PERROR("ustctl_get_mmap_read_offset");
		written = ret;
		goto end;
	}

	/* Handle stream on the relayd if the output is on the network */
	if (relayd) {
		if (stream->metadata_flag) {
			/* Only lock if metadata since we use the control socket. */
			pthread_mutex_lock(&relayd->ctrl_sock_mutex);
		}

		ret = consumer_handle_stream_before_relayd(stream, len);
		if (ret >= 0) {
			outfd = ret;

			/* Write metadata stream id before payload */
			if (stream->metadata_flag) {
				metadata_id = htobe64(stream->relayd_stream_id);
				do {
					ret = write(outfd, (void *) &metadata_id,
							sizeof(stream->relayd_stream_id));
				} while (ret < 0 && errno == EINTR);
				if (ret < 0) {
					PERROR("write metadata stream id");
					written = ret;
					goto end;
				}
				DBG("Metadata stream id %zu written before data",
						stream->relayd_stream_id);
			}
		}
		/* Else, use the default set before which is the filesystem. */
	}

	while (len > 0) {
		do {
			ret = write(outfd, stream->mmap_base + mmap_offset, len);
		} while (ret < 0 && errno == EINTR);
		if (ret < 0) {
			PERROR("Error in file write");
			if (written == 0) {
				written = ret;
			}
			goto end;
		} else if (ret > len) {
			PERROR("ret %ld > len %lu", ret, len);
			written += ret;
			goto end;
		} else {
			len -= ret;
			mmap_offset += ret;
		}
		DBG("UST mmap write() ret %ld (len %lu)", ret, len);

		/* This call is useless on a socket so better save a syscall. */
		if (!relayd) {
			/* This won't block, but will start writeout asynchronously */
			lttng_sync_file_range(outfd, stream->out_fd_offset, ret,
					SYNC_FILE_RANGE_WRITE);
			stream->out_fd_offset += ret;
		}
		written += ret;
	}
	lttng_consumer_sync_trace_file(stream, orig_offset);

end:
	if (relayd && stream->metadata_flag) {
		pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
	}
	rcu_read_unlock();
	return written;
}

/*
 * Splice the data from the ring buffer to the tracefile.
 *
 * Returns the number of bytes spliced.
 */
ssize_t lttng_ustconsumer_on_read_subbuffer_splice(
		struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream, unsigned long len)
{
	return -ENOSYS;
}

/*
 * Take a snapshot for a specific fd
 *
 * Returns 0 on success, < 0 on error
 */
int lttng_ustconsumer_take_snapshot(struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream)
{
	int ret = 0;

	ret = ustctl_snapshot(stream->chan->handle, stream->buf);
	if (ret != 0) {
		errno = -ret;
		PERROR("Getting sub-buffer snapshot.");
	}

	return ret;
}

/*
 * Get the produced position
 *
 * Returns 0 on success, < 0 on error
 */
int lttng_ustconsumer_get_produced_snapshot(
		struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream,
		unsigned long *pos)
{
	int ret;

	ret = ustctl_snapshot_get_produced(stream->chan->handle,
			stream->buf, pos);
	if (ret != 0) {
		errno = -ret;
		PERROR("kernctl_snapshot_get_produced");
	}

	return ret;
}

int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
		int sock, struct pollfd *consumer_sockpoll)
{
	ssize_t ret;
	struct lttcomm_consumer_msg msg;

	ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
	if (ret != sizeof(msg)) {
		lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
		return ret;
	}
	if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
		return -ENOENT;
	}

	/* relayd need RCU read-side lock */
	rcu_read_lock();

	switch (msg.cmd_type) {
	case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
	{
		int fd;
		struct consumer_relayd_sock_pair *relayd;

		DBG("UST Consumer adding relayd socket");

		/* Get relayd reference if exists. */
		relayd = consumer_find_relayd(msg.u.relayd_sock.net_index);
		if (relayd == NULL) {
			/* Not found. Allocate one. */
			relayd = consumer_allocate_relayd_sock_pair(
					msg.u.relayd_sock.net_index);
			if (relayd == NULL) {
				lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
				goto end_nosignal;
			}
		}

		/* Poll on consumer socket. */
		if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
			return -EINTR;
		}

		/* Get relayd socket from session daemon */
		ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
		if (ret != sizeof(fd)) {
			lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
			goto end_nosignal;
		}

		/* Copy socket information and received FD */
		switch (msg.u.relayd_sock.type) {
		case LTTNG_STREAM_CONTROL:
			/* Copy received lttcomm socket */
			lttcomm_copy_sock(&relayd->control_sock, &msg.u.relayd_sock.sock);
			ret = lttcomm_create_sock(&relayd->control_sock);
			if (ret < 0) {
				goto end_nosignal;
			}

			/* Close the created socket fd which is useless */
			close(relayd->control_sock.fd);

			/* Assign new file descriptor */
			relayd->control_sock.fd = fd;
			break;
		case LTTNG_STREAM_DATA:
			/* Copy received lttcomm socket */
			lttcomm_copy_sock(&relayd->data_sock, &msg.u.relayd_sock.sock);
			ret = lttcomm_create_sock(&relayd->data_sock);
			if (ret < 0) {
				goto end_nosignal;
			}

			/* Close the created socket fd which is useless */
			close(relayd->data_sock.fd);

			/* Assign new file descriptor */
			relayd->data_sock.fd = fd;
			break;
		default:
			ERR("Unknown relayd socket type");
			goto end_nosignal;
		}

		DBG("Consumer %s socket created successfully with net idx %d (fd: %d)",
				msg.u.relayd_sock.type == LTTNG_STREAM_CONTROL ? "control" : "data",
				relayd->net_seq_idx, fd);

		/*
		 * Add relayd socket pair to consumer data hashtable. If object already
		 * exists or on error, the function gracefully returns.
		 */
		consumer_add_relayd(relayd);

		goto end_nosignal;
	}
	case LTTNG_CONSUMER_ADD_CHANNEL:
	{
		struct lttng_consumer_channel *new_channel;
		int fds[1];
		size_t nb_fd = 1;

		/* block */
		if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
			return -EINTR;
		}
		ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
		if (ret != sizeof(fds)) {
			lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
			return ret;
		}

		DBG("consumer_add_channel %d", msg.u.channel.channel_key);

		new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
				fds[0], -1,
				msg.u.channel.mmap_len,
				msg.u.channel.max_sb_size);
		if (new_channel == NULL) {
			lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
			goto end_nosignal;
		}
		if (ctx->on_recv_channel != NULL) {
			ret = ctx->on_recv_channel(new_channel);
			if (ret == 0) {
				consumer_add_channel(new_channel);
			} else if (ret < 0) {
				goto end_nosignal;
			}
		} else {
			consumer_add_channel(new_channel);
		}
		goto end_nosignal;
	}
	case LTTNG_CONSUMER_ADD_STREAM:
	{
		struct lttng_consumer_stream *new_stream;
		int fds[2];
		size_t nb_fd = 2;
		struct consumer_relayd_sock_pair *relayd = NULL;

		/* block */
		if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
			return -EINTR;
		}
		ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
		if (ret != sizeof(fds)) {
			lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
			return ret;
		}

		assert(msg.u.stream.output == LTTNG_EVENT_MMAP);
		new_stream = consumer_allocate_stream(msg.u.channel.channel_key,
				msg.u.stream.stream_key,
				fds[0], fds[1],
				msg.u.stream.state,
				msg.u.stream.mmap_len,
				msg.u.stream.output,
				msg.u.stream.path_name,
				msg.u.stream.uid,
				msg.u.stream.gid,
				msg.u.stream.net_index,
				msg.u.stream.metadata_flag);
		if (new_stream == NULL) {
			lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
			goto end;
		}

		/* The stream is not metadata. Get relayd reference if exists. */
		relayd = consumer_find_relayd(msg.u.stream.net_index);
		if (relayd != NULL) {
			pthread_mutex_lock(&relayd->ctrl_sock_mutex);
			/* Add stream on the relayd */
			ret = relayd_add_stream(&relayd->control_sock,
					msg.u.stream.name, msg.u.stream.path_name,
					&new_stream->relayd_stream_id);
			pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
			if (ret < 0) {
				goto end;
			}
		} else if (msg.u.stream.net_index != -1) {
			ERR("Network sequence index %d unknown. Not adding stream.",
					msg.u.stream.net_index);
			free(new_stream);
			goto end;
		}

		if (ctx->on_recv_stream != NULL) {
			ret = ctx->on_recv_stream(new_stream);
			if (ret == 0) {
				consumer_add_stream(new_stream);
			} else if (ret < 0) {
				goto end;
			}
		} else {
			consumer_add_stream(new_stream);
		}

		DBG("UST consumer_add_stream %s (%d,%d) with relayd id %lu",
				msg.u.stream.path_name, fds[0], fds[1],
				new_stream->relayd_stream_id);
		break;
	}
	case LTTNG_CONSUMER_UPDATE_STREAM:
	{
		return -ENOSYS;
#if 0
		if (ctx->on_update_stream != NULL) {
			ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state);
			if (ret == 0) {
				consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state);
			} else if (ret < 0) {
				goto end;
			}
		} else {
			consumer_change_stream_state(msg.u.stream.stream_key,
				msg.u.stream.state);
		}
#endif
		break;
	}
	default:
		break;
	}
end:
	/*
	 * Wake-up the other end by writing a null byte in the pipe
	 * (non-blocking). Important note: Because writing into the
	 * pipe is non-blocking (and therefore we allow dropping wakeup
	 * data, as long as there is wakeup data present in the pipe
	 * buffer to wake up the other end), the other end should
	 * perform the following sequence for waiting:
	 * 1) empty the pipe (reads).
	 * 2) perform update operation.
	 * 3) wait on the pipe (poll).
	 */
	do {
		ret = write(ctx->consumer_poll_pipe[1], "", 1);
	} while (ret < 0 && errno == EINTR);
end_nosignal:
	rcu_read_unlock();
	return 0;
}

int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
{
	struct lttng_ust_object_data obj;

	obj.handle = -1;
	obj.shm_fd = chan->shm_fd;
	obj.wait_fd = chan->wait_fd;
	obj.memory_map_size = chan->mmap_len;
	chan->handle = ustctl_map_channel(&obj);
	if (!chan->handle) {
		return -ENOMEM;
	}
	chan->wait_fd_is_copy = 1;
	chan->shm_fd = -1;

	return 0;
}

void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
{
	ustctl_flush_buffer(stream->chan->handle, stream->buf, 0);
	stream->hangup_flush_done = 1;
}

void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
{
	ustctl_unmap_channel(chan->handle);
}

int lttng_ustconsumer_allocate_stream(struct lttng_consumer_stream *stream)
{
	struct lttng_ust_object_data obj;
	int ret;

	obj.handle = -1;
	obj.shm_fd = stream->shm_fd;
	obj.wait_fd = stream->wait_fd;
	obj.memory_map_size = stream->mmap_len;
	ret = ustctl_add_stream(stream->chan->handle, &obj);
	if (ret)
		return ret;
	stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu);
	if (!stream->buf)
		return -EBUSY;
	/* ustctl_open_stream_read has closed the shm fd. */
	stream->wait_fd_is_copy = 1;
	stream->shm_fd = -1;

	stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf);
	if (!stream->mmap_base) {
		return -EINVAL;
	}

	return 0;
}

void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
{
	ustctl_close_stream_read(stream->chan->handle, stream->buf);
}


int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
		struct lttng_consumer_local_data *ctx)
{
	unsigned long len;
	int err;
	long ret = 0;
	struct lttng_ust_shm_handle *handle;
	struct lttng_ust_lib_ring_buffer *buf;
	char dummy;
	ssize_t readlen;

	DBG("In read_subbuffer (wait_fd: %d, stream key: %d)",
		stream->wait_fd, stream->key);

	/* We can consume the 1 byte written into the wait_fd by UST */
	if (!stream->hangup_flush_done) {
		do {
			readlen = read(stream->wait_fd, &dummy, 1);
		} while (readlen == -1 && errno == EINTR);
		if (readlen == -1) {
			ret = readlen;
			goto end;
		}
	}

	buf = stream->buf;
	handle = stream->chan->handle;
	/* Get the next subbuffer */
	err = ustctl_get_next_subbuf(handle, buf);
	if (err != 0) {
		ret = -ret;	/* ustctl_get_next_subbuf returns negative, caller expect positive. */
		/*
		 * This is a debug message even for single-threaded consumer,
		 * because poll() have more relaxed criterions than get subbuf,
		 * so get_subbuf may fail for short race windows where poll()
		 * would issue wakeups.
		 */
		DBG("Reserving sub buffer failed (everything is normal, "
				"it is due to concurrency)");
		goto end;
	}
	assert(stream->output == LTTNG_EVENT_MMAP);
	/* read the used subbuffer size */
	err = ustctl_get_padded_subbuf_size(handle, buf, &len);
	assert(err == 0);
	/* write the subbuffer to the tracefile */
	ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len);
	if (ret != len) {
		/*
		 * display the error but continue processing to try
		 * to release the subbuffer
		 */
		ERR("Error writing to tracefile");
	}
	err = ustctl_put_next_subbuf(handle, buf);
	assert(err == 0);
end:
	return ret;
}

int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
{
	int ret;

	/* Opening the tracefile in write mode */
	if (stream->path_name != NULL && stream->net_seq_idx == -1) {
		ret = run_as_open(stream->path_name,
				O_WRONLY|O_CREAT|O_TRUNC,
				S_IRWXU|S_IRWXG|S_IRWXO,
				stream->uid, stream->gid);
		if (ret < 0) {
			ERR("Opening %s", stream->path_name);
			PERROR("open");
			goto error;
		}
		stream->out_fd = ret;
	}

	/* we return 0 to let the library handle the FD internally */
	return 0;

error:
	return ret;
}
Commit	Line	Data
3bd1e081 MD	1	/*
	2	* Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
	3	* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	4	*
d14d33bf AM	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License, version 2 only,
	7	* as published by the Free Software Foundation.
3bd1e081 MD	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
d14d33bf AM	14	* You should have received a copy of the GNU General Public License along
	15	* with this program; if not, write to the Free Software Foundation, Inc.,
	16	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
3bd1e081 MD	17	*/
	18
	19	#define _GNU_SOURCE
	20	#include <assert.h>
3bd1e081 MD	21	#include <poll.h>
	22	#include <pthread.h>
	23	#include <stdlib.h>
	24	#include <string.h>
	25	#include <sys/mman.h>
	26	#include <sys/socket.h>
dbb5dfe6	27	#include <sys/stat.h>
3bd1e081 MD	28	#include <sys/types.h>
3bd1e081 MD	29	#include <unistd.h>
9df8df5e	30	#include <lttng/ust-ctl.h>
0857097f	31
990570ed	32	#include <common/common.h>
10a8a223	33	#include <common/sessiond-comm/sessiond-comm.h>
00e2e675	34	#include <common/relayd/relayd.h>
dbb5dfe6	35	#include <common/compat/fcntl.h>
10a8a223 DG	36
10a8a223 DG	37	#include "ust-consumer.h"
3bd1e081 MD	38
	39	extern struct lttng_consumer_global_data consumer_data;
	40	extern int consumer_poll_timeout;
	41	extern volatile int consumer_quit;
	42
	43	/*
	44	* Mmap the ring buffer, read it and write the data to the tracefile.
	45	*
4078b776	46	* Returns the number of bytes written, else negative value on error.
3bd1e081	47	*/
4078b776	48	ssize_t lttng_ustconsumer_on_read_subbuffer_mmap(
3bd1e081 MD	49	struct lttng_consumer_local_data *ctx,
	50	struct lttng_consumer_stream *stream, unsigned long len)
	51	{
	52	unsigned long mmap_offset;
47e81c02	53	long ret = 0, written = 0;
3bd1e081 MD	54	off_t orig_offset = stream->out_fd_offset;
3bd1e081 MD	55	int outfd = stream->out_fd;
00e2e675 DG	56	uint64_t metadata_id;
	57	struct consumer_relayd_sock_pair *relayd = NULL;
	58
b0b335c8 MD	59	/* RCU lock for the relayd pointer */
	60	rcu_read_lock();
	61
00e2e675 DG	62	/* Flag that the current stream if set for network streaming. */
	63	if (stream->net_seq_idx != -1) {
	64	relayd = consumer_find_relayd(stream->net_seq_idx);
	65	if (relayd == NULL) {
87c1611d DG	66	ERR("UST consumer mmap(), unable to find relay for index %d",
87c1611d DG	67	stream->net_seq_idx);
00e2e675 DG	68	goto end;
	69	}
	70	}
3bd1e081 MD	71
	72	/* get the offset inside the fd to mmap */
	73	ret = ustctl_get_mmap_read_offset(stream->chan->handle,
	74	stream->buf, &mmap_offset);
	75	if (ret != 0) {
87dc6a9c	76	errno = -ret;
4c462e79	77	PERROR("ustctl_get_mmap_read_offset");
47e81c02	78	written = ret;
3bd1e081 MD	79	goto end;
3bd1e081 MD	80	}
00e2e675 DG	81
	82	/* Handle stream on the relayd if the output is on the network */
	83	if (relayd) {
	84	if (stream->metadata_flag) {
	85	/* Only lock if metadata since we use the control socket. */
	86	pthread_mutex_lock(&relayd->ctrl_sock_mutex);
	87	}
	88
	89	ret = consumer_handle_stream_before_relayd(stream, len);
	90	if (ret >= 0) {
	91	outfd = ret;
	92
	93	/* Write metadata stream id before payload */
	94	if (stream->metadata_flag) {
	95	metadata_id = htobe64(stream->relayd_stream_id);
	96	do {
	97	ret = write(outfd, (void *) &metadata_id,
	98	sizeof(stream->relayd_stream_id));
6f94560a MD	99	} while (ret < 0 && errno == EINTR);
	100	if (ret < 0) {
	101	PERROR("write metadata stream id");
	102	written = ret;
	103	goto end;
	104	}
00e2e675 DG	105	DBG("Metadata stream id %zu written before data",
	106	stream->relayd_stream_id);
	107	}
	108	}
	109	/* Else, use the default set before which is the filesystem. */
	110	}
	111
3bd1e081	112	while (len > 0) {
6f94560a MD	113	do {
	114	ret = write(outfd, stream->mmap_base + mmap_offset, len);
	115	} while (ret < 0 && errno == EINTR);
47e81c02	116	if (ret < 0) {
6f94560a MD	117	PERROR("Error in file write");
	118	if (written == 0) {
	119	written = ret;
47e81c02	120	}
6f94560a	121	goto end;
47e81c02	122	} else if (ret > len) {
00e2e675	123	PERROR("ret %ld > len %lu", ret, len);
47e81c02	124	written += ret;
3bd1e081	125	goto end;
47e81c02 MD	126	} else {
	127	len -= ret;
	128	mmap_offset += ret;
3bd1e081	129	}
00e2e675 DG	130	DBG("UST mmap write() ret %ld (len %lu)", ret, len);
	131
	132	/* This call is useless on a socket so better save a syscall. */
	133	if (!relayd) {
	134	/* This won't block, but will start writeout asynchronously */
	135	lttng_sync_file_range(outfd, stream->out_fd_offset, ret,
	136	SYNC_FILE_RANGE_WRITE);
	137	stream->out_fd_offset += ret;
	138	}
47e81c02	139	written += ret;
3bd1e081	140	}
3bd1e081	141	lttng_consumer_sync_trace_file(stream, orig_offset);
00e2e675	142
3bd1e081	143	end:
00e2e675 DG	144	if (relayd && stream->metadata_flag) {
	145	pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
	146	}
b0b335c8	147	rcu_read_unlock();
47e81c02	148	return written;
3bd1e081 MD	149	}
	150
	151	/*
	152	* Splice the data from the ring buffer to the tracefile.
	153	*
	154	* Returns the number of bytes spliced.
	155	*/
4078b776	156	ssize_t lttng_ustconsumer_on_read_subbuffer_splice(
3bd1e081 MD	157	struct lttng_consumer_local_data *ctx,
	158	struct lttng_consumer_stream *stream, unsigned long len)
	159	{
	160	return -ENOSYS;
	161	}
	162
	163	/*
	164	* Take a snapshot for a specific fd
	165	*
	166	* Returns 0 on success, < 0 on error
	167	*/
	168	int lttng_ustconsumer_take_snapshot(struct lttng_consumer_local_data *ctx,
	169	struct lttng_consumer_stream *stream)
	170	{
	171	int ret = 0;
	172
	173	ret = ustctl_snapshot(stream->chan->handle, stream->buf);
	174	if (ret != 0) {
87dc6a9c	175	errno = -ret;
4c462e79	176	PERROR("Getting sub-buffer snapshot.");
3bd1e081 MD	177	}
	178
	179	return ret;
	180	}
	181
	182	/*
	183	* Get the produced position
	184	*
	185	* Returns 0 on success, < 0 on error
	186	*/
	187	int lttng_ustconsumer_get_produced_snapshot(
	188	struct lttng_consumer_local_data *ctx,
	189	struct lttng_consumer_stream *stream,
	190	unsigned long *pos)
	191	{
	192	int ret;
	193
	194	ret = ustctl_snapshot_get_produced(stream->chan->handle,
	195	stream->buf, pos);
	196	if (ret != 0) {
87dc6a9c	197	errno = -ret;
4c462e79	198	PERROR("kernctl_snapshot_get_produced");
3bd1e081 MD	199	}
	200
	201	return ret;
	202	}
	203
	204	int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
	205	int sock, struct pollfd *consumer_sockpoll)
	206	{
	207	ssize_t ret;
	208	struct lttcomm_consumer_msg msg;
	209
	210	ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
	211	if (ret != sizeof(msg)) {
	212	lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
	213	return ret;
	214	}
	215	if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
	216	return -ENOENT;
	217	}
	218
b0b335c8 MD	219	/* relayd need RCU read-side lock */
	220	rcu_read_lock();
	221
3bd1e081	222	switch (msg.cmd_type) {
00e2e675 DG	223	case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
	224	{
	225	int fd;
	226	struct consumer_relayd_sock_pair *relayd;
	227
	228	DBG("UST Consumer adding relayd socket");
	229
	230	/* Get relayd reference if exists. */
	231	relayd = consumer_find_relayd(msg.u.relayd_sock.net_index);
	232	if (relayd == NULL) {
	233	/* Not found. Allocate one. */
	234	relayd = consumer_allocate_relayd_sock_pair(
	235	msg.u.relayd_sock.net_index);
	236	if (relayd == NULL) {
	237	lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
	238	goto end_nosignal;
	239	}
	240	}
	241
	242	/* Poll on consumer socket. */
	243	if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
	244	return -EINTR;
	245	}
	246
	247	/* Get relayd socket from session daemon */
	248	ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
	249	if (ret != sizeof(fd)) {
	250	lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
	251	goto end_nosignal;
	252	}
	253
	254	/* Copy socket information and received FD */
	255	switch (msg.u.relayd_sock.type) {
	256	case LTTNG_STREAM_CONTROL:
	257	/* Copy received lttcomm socket */
	258	lttcomm_copy_sock(&relayd->control_sock, &msg.u.relayd_sock.sock);
	259	ret = lttcomm_create_sock(&relayd->control_sock);
	260	if (ret < 0) {
	261	goto end_nosignal;
	262	}
	263
	264	/* Close the created socket fd which is useless */
	265	close(relayd->control_sock.fd);
	266
	267	/* Assign new file descriptor */
	268	relayd->control_sock.fd = fd;
	269	break;
	270	case LTTNG_STREAM_DATA:
	271	/* Copy received lttcomm socket */
	272	lttcomm_copy_sock(&relayd->data_sock, &msg.u.relayd_sock.sock);
	273	ret = lttcomm_create_sock(&relayd->data_sock);
	274	if (ret < 0) {
	275	goto end_nosignal;
	276	}
	277
	278	/* Close the created socket fd which is useless */
	279	close(relayd->data_sock.fd);
	280
	281	/* Assign new file descriptor */
	282	relayd->data_sock.fd = fd;
	283	break;
	284	default:
	285	ERR("Unknown relayd socket type");
	286	goto end_nosignal;
287	}
288
289	DBG("Consumer %s socket created successfully with net idx %d (fd: %d)",
290	msg.u.relayd_sock.type == LTTNG_STREAM_CONTROL ? "control" : "data",
291	relayd->net_seq_idx, fd);
292
293	/*
294	* Add relayd socket pair to consumer data hashtable. If object already
295	* exists or on error, the function gracefully returns.
296	*/
297	consumer_add_relayd(relayd);
298
299	goto end_nosignal;
300	}
3bd1e081 MD	301	case LTTNG_CONSUMER_ADD_CHANNEL:
	302	{
	303	struct lttng_consumer_channel *new_channel;
	304	int fds[1];
	305	size_t nb_fd = 1;
	306
	307	/* block */
	308	if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
	309	return -EINTR;
	310	}
	311	ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
	312	if (ret != sizeof(fds)) {
	313	lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
	314	return ret;
	315	}
	316
	317	DBG("consumer_add_channel %d", msg.u.channel.channel_key);
	318
	319	new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
	320	fds[0], -1,
	321	msg.u.channel.mmap_len,
	322	msg.u.channel.max_sb_size);
	323	if (new_channel == NULL) {
	324	lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
	325	goto end_nosignal;
	326	}
	327	if (ctx->on_recv_channel != NULL) {
	328	ret = ctx->on_recv_channel(new_channel);
	329	if (ret == 0) {
	330	consumer_add_channel(new_channel);
	331	} else if (ret < 0) {
	332	goto end_nosignal;
	333	}
	334	} else {
	335	consumer_add_channel(new_channel);
	336	}
	337	goto end_nosignal;
	338	}
	339	case LTTNG_CONSUMER_ADD_STREAM:
	340	{
	341	struct lttng_consumer_stream *new_stream;
	342	int fds[2];
	343	size_t nb_fd = 2;
00e2e675	344	struct consumer_relayd_sock_pair *relayd = NULL;
3bd1e081 MD	345
	346	/* block */
	347	if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
	348	return -EINTR;
	349	}
	350	ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
	351	if (ret != sizeof(fds)) {
	352	lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
	353	return ret;
	354	}
	355
d41f73b7	356	assert(msg.u.stream.output == LTTNG_EVENT_MMAP);
7ad0a0cb	357	new_stream = consumer_allocate_stream(msg.u.channel.channel_key,
3bd1e081 MD	358	msg.u.stream.stream_key,
	359	fds[0], fds[1],
	360	msg.u.stream.state,
	361	msg.u.stream.mmap_len,
	362	msg.u.stream.output,
6df2e2c9 MD	363	msg.u.stream.path_name,
6df2e2c9 MD	364	msg.u.stream.uid,
00e2e675 DG	365	msg.u.stream.gid,
	366	msg.u.stream.net_index,
	367	msg.u.stream.metadata_flag);
3bd1e081 MD	368	if (new_stream == NULL) {
	369	lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
	370	goto end;
	371	}
00e2e675 DG	372
	373	/* The stream is not metadata. Get relayd reference if exists. */
	374	relayd = consumer_find_relayd(msg.u.stream.net_index);
	375	if (relayd != NULL) {
	376	pthread_mutex_lock(&relayd->ctrl_sock_mutex);
	377	/* Add stream on the relayd */
	378	ret = relayd_add_stream(&relayd->control_sock,
	379	msg.u.stream.name, msg.u.stream.path_name,
	380	&new_stream->relayd_stream_id);
	381	pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
	382	if (ret < 0) {
	383	goto end;
	384	}
	385	} else if (msg.u.stream.net_index != -1) {
	386	ERR("Network sequence index %d unknown. Not adding stream.",
	387	msg.u.stream.net_index);
	388	free(new_stream);
	389	goto end;
	390	}
	391
3bd1e081 MD	392	if (ctx->on_recv_stream != NULL) {
	393	ret = ctx->on_recv_stream(new_stream);
	394	if (ret == 0) {
	395	consumer_add_stream(new_stream);
	396	} else if (ret < 0) {
	397	goto end;
	398	}
	399	} else {
	400	consumer_add_stream(new_stream);
	401	}
00e2e675 DG	402
	403	DBG("UST consumer_add_stream %s (%d,%d) with relayd id %lu",
	404	msg.u.stream.path_name, fds[0], fds[1],
	405	new_stream->relayd_stream_id);
3bd1e081 MD	406	break;
	407	}
	408	case LTTNG_CONSUMER_UPDATE_STREAM:
	409	{
7ad0a0cb MD	410	return -ENOSYS;
7ad0a0cb MD	411	#if 0
3bd1e081 MD	412	if (ctx->on_update_stream != NULL) {
	413	ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state);
	414	if (ret == 0) {
	415	consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state);
	416	} else if (ret < 0) {
	417	goto end;
	418	}
	419	} else {
	420	consumer_change_stream_state(msg.u.stream.stream_key,
	421	msg.u.stream.state);
	422	}
7ad0a0cb	423	#endif
3bd1e081 MD	424	break;
	425	}
	426	default:
	427	break;
	428	}
	429	end:
04fdd819 MD	430	/*
	431	* Wake-up the other end by writing a null byte in the pipe
	432	* (non-blocking). Important note: Because writing into the
	433	* pipe is non-blocking (and therefore we allow dropping wakeup
	434	* data, as long as there is wakeup data present in the pipe
	435	* buffer to wake up the other end), the other end should
	436	* perform the following sequence for waiting:
	437	* 1) empty the pipe (reads).
	438	* 2) perform update operation.
	439	* 3) wait on the pipe (poll).
	440	*/
	441	do {
	442	ret = write(ctx->consumer_poll_pipe[1], "", 1);
6f94560a	443	} while (ret < 0 && errno == EINTR);
3bd1e081	444	end_nosignal:
b0b335c8	445	rcu_read_unlock();
3bd1e081 MD	446	return 0;
	447	}
	448
	449	int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
	450	{
13161846	451	struct lttng_ust_object_data obj;
3bd1e081 MD	452
	453	obj.handle = -1;
	454	obj.shm_fd = chan->shm_fd;
	455	obj.wait_fd = chan->wait_fd;
	456	obj.memory_map_size = chan->mmap_len;
	457	chan->handle = ustctl_map_channel(&obj);
	458	if (!chan->handle) {
	459	return -ENOMEM;
	460	}
b5c5fc29	461	chan->wait_fd_is_copy = 1;
2c1dd183	462	chan->shm_fd = -1;
b5c5fc29	463
3bd1e081 MD	464	return 0;
	465	}
	466
d056b477 MD	467	void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
	468	{
	469	ustctl_flush_buffer(stream->chan->handle, stream->buf, 0);
effcf122	470	stream->hangup_flush_done = 1;
d056b477 MD	471	}
d056b477 MD	472
3bd1e081 MD	473	void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
	474	{
	475	ustctl_unmap_channel(chan->handle);
	476	}
	477
	478	int lttng_ustconsumer_allocate_stream(struct lttng_consumer_stream *stream)
	479	{
13161846	480	struct lttng_ust_object_data obj;
3bd1e081 MD	481	int ret;
	482
	483	obj.handle = -1;
	484	obj.shm_fd = stream->shm_fd;
	485	obj.wait_fd = stream->wait_fd;
	486	obj.memory_map_size = stream->mmap_len;
	487	ret = ustctl_add_stream(stream->chan->handle, &obj);
	488	if (ret)
	489	return ret;
	490	stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu);
	491	if (!stream->buf)
	492	return -EBUSY;
2c1dd183 MD	493	/* ustctl_open_stream_read has closed the shm fd. */
	494	stream->wait_fd_is_copy = 1;
	495	stream->shm_fd = -1;
	496
3bd1e081 MD	497	stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf);
	498	if (!stream->mmap_base) {
	499	return -EINVAL;
	500	}
ee77a7b0	501
3bd1e081 MD	502	return 0;
	503	}
	504
	505	void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
	506	{
	507	ustctl_close_stream_read(stream->chan->handle, stream->buf);
	508	}
d41f73b7 MD	509
	510
	511	int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
	512	struct lttng_consumer_local_data *ctx)
	513	{
	514	unsigned long len;
	515	int err;
	516	long ret = 0;
	517	struct lttng_ust_shm_handle *handle;
	518	struct lttng_ust_lib_ring_buffer *buf;
	519	char dummy;
	520	ssize_t readlen;
	521
	522	DBG("In read_subbuffer (wait_fd: %d, stream key: %d)",
	523	stream->wait_fd, stream->key);
	524
	525	/* We can consume the 1 byte written into the wait_fd by UST */
effcf122 MD	526	if (!stream->hangup_flush_done) {
	527	do {
	528	readlen = read(stream->wait_fd, &dummy, 1);
87dc6a9c	529	} while (readlen == -1 && errno == EINTR);
effcf122 MD	530	if (readlen == -1) {
	531	ret = readlen;
	532	goto end;
	533	}
d41f73b7 MD	534	}
	535
	536	buf = stream->buf;
	537	handle = stream->chan->handle;
	538	/* Get the next subbuffer */
	539	err = ustctl_get_next_subbuf(handle, buf);
	540	if (err != 0) {
effcf122	541	ret = -ret; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
d41f73b7 MD	542	/*
	543	* This is a debug message even for single-threaded consumer,
	544	* because poll() have more relaxed criterions than get subbuf,
	545	* so get_subbuf may fail for short race windows where poll()
	546	* would issue wakeups.
	547	*/
	548	DBG("Reserving sub buffer failed (everything is normal, "
	549	"it is due to concurrency)");
	550	goto end;
	551	}
	552	assert(stream->output == LTTNG_EVENT_MMAP);
	553	/* read the used subbuffer size */
	554	err = ustctl_get_padded_subbuf_size(handle, buf, &len);
effcf122	555	assert(err == 0);
d41f73b7 MD	556	/* write the subbuffer to the tracefile */
d41f73b7 MD	557	ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len);
47e81c02	558	if (ret != len) {
d41f73b7 MD	559	/*
	560	* display the error but continue processing to try
	561	* to release the subbuffer
	562	*/
	563	ERR("Error writing to tracefile");
	564	}
	565	err = ustctl_put_next_subbuf(handle, buf);
effcf122	566	assert(err == 0);
d41f73b7 MD	567	end:
	568	return ret;
	569	}
	570
	571	int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
	572	{
	573	int ret;
	574
	575	/* Opening the tracefile in write mode */
00e2e675	576	if (stream->path_name != NULL && stream->net_seq_idx == -1) {
e11d277b	577	ret = run_as_open(stream->path_name,
60b6c79c MD	578	O_WRONLY\|O_CREAT\|O_TRUNC,
	579	S_IRWXU\|S_IRWXG\|S_IRWXO,
	580	stream->uid, stream->gid);
d41f73b7 MD	581	if (ret < 0) {
d41f73b7 MD	582	ERR("Opening %s", stream->path_name);
4c462e79	583	PERROR("open");
d41f73b7 MD	584	goto error;
	585	}
	586	stream->out_fd = ret;
	587	}
	588
	589	/* we return 0 to let the library handle the FD internally */
	590	return 0;
	591
	592	error:
	593	return ret;
	594	}