+++ /dev/null
-/*
- * 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
- * as published by the Free Software Foundation; only version 2
- * of the License.
- *
- * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-
-#define _GNU_SOURCE
-#include <assert.h>
-#include <fcntl.h>
-#include <poll.h>
-#include <pthread.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/mman.h>
-#include <sys/socket.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include <lttng-kernel-ctl.h>
-#include <lttng-sessiond-comm.h>
-#include <lttng/lttng-kconsumer.h>
-#include <lttngerr.h>
-
-#include "common/runas.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
- */
-int lttng_kconsumer_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;
- off_t orig_offset = stream->out_fd_offset;
- int fd = stream->wait_fd;
- int outfd = stream->out_fd;
-
- /* get the offset inside the fd to mmap */
- ret = kernctl_get_mmap_read_offset(fd, &mmap_offset);
- if (ret != 0) {
- ret = -errno;
- perror("kernctl_get_mmap_read_offset");
- goto end;
- }
-
- while (len > 0) {
- ret = write(outfd, stream->mmap_base + mmap_offset, len);
- if (ret >= len) {
- len = 0;
- } else if (ret < 0) {
- ret = -errno;
- perror("Error in file write");
- goto end;
- }
- /* This won't block, but will start writeout asynchronously */
- sync_file_range(outfd, stream->out_fd_offset, ret,
- SYNC_FILE_RANGE_WRITE);
- stream->out_fd_offset += ret;
- }
-
- lttng_consumer_sync_trace_file(stream, orig_offset);
-
- goto end;
-
-end:
- return ret;
-}
-
-/*
- * Splice the data from the ring buffer to the tracefile.
- *
- * Returns the number of bytes spliced.
- */
-int lttng_kconsumer_on_read_subbuffer_splice(
- struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream, unsigned long len)
-{
- long ret = 0;
- loff_t offset = 0;
- off_t orig_offset = stream->out_fd_offset;
- int fd = stream->wait_fd;
- int outfd = stream->out_fd;
-
- while (len > 0) {
- DBG("splice chan to pipe offset %lu (fd : %d)",
- (unsigned long)offset, fd);
- ret = splice(fd, &offset, ctx->consumer_thread_pipe[1], NULL, len,
- SPLICE_F_MOVE | SPLICE_F_MORE);
- DBG("splice chan to pipe ret %ld", ret);
- if (ret < 0) {
- ret = errno;
- perror("Error in relay splice");
- goto splice_error;
- }
-
- ret = splice(ctx->consumer_thread_pipe[0], NULL, outfd, NULL, ret,
- SPLICE_F_MOVE | SPLICE_F_MORE);
- DBG("splice pipe to file %ld", ret);
- if (ret < 0) {
- ret = errno;
- perror("Error in file splice");
- goto splice_error;
- }
- len -= ret;
- /* This won't block, but will start writeout asynchronously */
- sync_file_range(outfd, stream->out_fd_offset, ret,
- SYNC_FILE_RANGE_WRITE);
- stream->out_fd_offset += ret;
- }
- lttng_consumer_sync_trace_file(stream, orig_offset);
-
- goto end;
-
-splice_error:
- /* send the appropriate error description to sessiond */
- switch(ret) {
- case EBADF:
- lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EBADF);
- break;
- case EINVAL:
- lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EINVAL);
- break;
- case ENOMEM:
- lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ENOMEM);
- break;
- case ESPIPE:
- lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ESPIPE);
- break;
- }
-
-end:
- return ret;
-}
-
-/*
- * Take a snapshot for a specific fd
- *
- * Returns 0 on success, < 0 on error
- */
-int lttng_kconsumer_take_snapshot(struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream)
-{
- int ret = 0;
- int infd = stream->wait_fd;
-
- ret = kernctl_snapshot(infd);
- if (ret != 0) {
- ret = errno;
- perror("Getting sub-buffer snapshot.");
- }
-
- return ret;
-}
-
-/*
- * Get the produced position
- *
- * Returns 0 on success, < 0 on error
- */
-int lttng_kconsumer_get_produced_snapshot(
- struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream,
- unsigned long *pos)
-{
- int ret;
- int infd = stream->wait_fd;
-
- ret = kernctl_snapshot_get_produced(infd, pos);
- if (ret != 0) {
- ret = errno;
- perror("kernctl_snapshot_get_produced");
- }
-
- return ret;
-}
-
-int lttng_kconsumer_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_CMD);
- return ret;
- }
- if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
- return -ENOENT;
- }
-
- switch (msg.cmd_type) {
- case LTTNG_CONSUMER_ADD_CHANNEL:
- {
- struct lttng_consumer_channel *new_channel;
-
- DBG("consumer_add_channel %d", msg.u.channel.channel_key);
- new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
- -1, -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 fd;
-
- /* block */
- if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
- return -EINTR;
- }
- ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
- if (ret != sizeof(fd)) {
- lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
- return ret;
- }
-
- DBG("consumer_add_stream %s (%d)", msg.u.stream.path_name,
- fd);
- new_stream = consumer_allocate_stream(msg.u.stream.channel_key,
- msg.u.stream.stream_key,
- fd, fd,
- 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);
- if (new_stream == NULL) {
- lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
- 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);
- }
- break;
- }
- case LTTNG_CONSUMER_UPDATE_STREAM:
- {
- 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);
- }
- break;
- }
- default:
- break;
- }
-end:
- /* signal the poll thread */
- ret = write(ctx->consumer_poll_pipe[1], "4", 1);
- if (ret < 0) {
- perror("write consumer poll");
- }
-end_nosignal:
- return 0;
-}
-
-/*
- * Consume data on a file descriptor and write it on a trace file.
- */
-int lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
- struct lttng_consumer_local_data *ctx)
-{
- unsigned long len;
- int err;
- long ret = 0;
- int infd = stream->wait_fd;
-
- DBG("In read_subbuffer (infd : %d)", infd);
- /* Get the next subbuffer */
- err = kernctl_get_next_subbuf(infd);
- if (err != 0) {
- ret = errno;
- /*
- * 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;
- }
-
- switch (stream->output) {
- case LTTNG_EVENT_SPLICE:
- /* read the whole subbuffer */
- err = kernctl_get_padded_subbuf_size(infd, &len);
- if (err != 0) {
- ret = errno;
- perror("Getting sub-buffer len failed.");
- goto end;
- }
-
- /* splice the subbuffer to the tracefile */
- ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, len);
- if (ret < 0) {
- /*
- * display the error but continue processing to try
- * to release the subbuffer
- */
- ERR("Error splicing to tracefile");
- }
- break;
- case LTTNG_EVENT_MMAP:
- /* read the used subbuffer size */
- err = kernctl_get_padded_subbuf_size(infd, &len);
- if (err != 0) {
- ret = errno;
- perror("Getting sub-buffer len failed.");
- goto end;
- }
- /* write the subbuffer to the tracefile */
- ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len);
- if (ret < 0) {
- /*
- * display the error but continue processing to try
- * to release the subbuffer
- */
- ERR("Error writing to tracefile");
- }
- break;
- default:
- ERR("Unknown output method");
- ret = -1;
- }
-
- err = kernctl_put_next_subbuf(infd);
- if (err != 0) {
- ret = errno;
- if (errno == EFAULT) {
- perror("Error in unreserving sub buffer\n");
- } else if (errno == EIO) {
- /* Should never happen with newer LTTng versions */
- perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
- }
- goto end;
- }
-
-end:
- return ret;
-}
-
-int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
-{
- int ret;
-
- /* Opening the tracefile in write mode */
- if (stream->path_name != NULL) {
- 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;
- }
-
- if (stream->output == LTTNG_EVENT_MMAP) {
- /* get the len of the mmap region */
- unsigned long mmap_len;
-
- ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len);
- if (ret != 0) {
- ret = errno;
- perror("kernctl_get_mmap_len");
- goto error_close_fd;
- }
- stream->mmap_len = (size_t) mmap_len;
-
- stream->mmap_base = mmap(NULL, stream->mmap_len,
- PROT_READ, MAP_PRIVATE, stream->wait_fd, 0);
- if (stream->mmap_base == MAP_FAILED) {
- perror("Error mmaping");
- ret = -1;
- goto error_close_fd;
- }
- }
-
- /* we return 0 to let the library handle the FD internally */
- return 0;
-
-error_close_fd:
- {
- int err;
-
- err = close(stream->out_fd);
- assert(!err);
- }
-error:
- return ret;
-}
-
projects / lttng-tools.git / blobdiff