[lttng-tools.git] / src / common / index / index.c

/*
 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
 *                      David Goulet <dgoulet@efficios.com>
 *               2016 - 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 _LGPL_SOURCE
#include <assert.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>

#include <lttng/constant.h>
#include <common/common.h>
#include <common/defaults.h>
#include <common/compat/endian.h>
#include <common/utils.h>

#include "index.h"

#define WRITE_FILE_FLAGS	(O_WRONLY | O_CREAT | O_TRUNC)
#define READ_ONLY_FILE_FLAGS	O_RDONLY

static struct lttng_index_file *_lttng_index_file_create_from_trace_chunk(
		struct lttng_trace_chunk *chunk,
		const char *channel_path, const char *stream_name,
		uint64_t stream_file_size, uint64_t stream_file_index,
		uint32_t index_major, uint32_t index_minor,
		bool unlink_existing_file,
		int flags)
{
	struct lttng_index_file *index_file;
	enum lttng_trace_chunk_status chunk_status;
	int ret, fd = -1;
	ssize_t size_ret;
	struct ctf_packet_index_file_hdr hdr;
	char index_directory_path[LTTNG_PATH_MAX];
	char index_file_path[LTTNG_PATH_MAX];
	const uint32_t element_len = ctf_packet_index_len(index_major,
			index_minor);
	const mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
	const bool acquired_reference = lttng_trace_chunk_get(chunk);

	assert(acquired_reference);

	index_file = zmalloc(sizeof(*index_file));
	if (!index_file) {
		PERROR("Failed to allocate lttng_index_file");
		goto error;
	}

	index_file->trace_chunk = chunk;
	ret = snprintf(index_directory_path, sizeof(index_directory_path),
			"%s/" DEFAULT_INDEX_DIR, channel_path);
	if (ret < 0 || ret >= sizeof(index_directory_path)) {
		ERR("Failed to format index directory path");
		goto error;
	}

	ret = utils_stream_file_path(index_directory_path, stream_name,
			stream_file_size, stream_file_index,
			DEFAULT_INDEX_FILE_SUFFIX,
			index_file_path, sizeof(index_file_path));
	if (ret) {
		goto error;
	}

	if (unlink_existing_file) {
		/*
		 * For tracefile rotation. We need to unlink the old
		 * file if present to synchronize with the tail of the
		 * live viewer which could be working on this same file.
		 * By doing so, any reference to the old index file
		 * stays valid even if we re-create a new file with the
		 * same name afterwards.
		 */
		chunk_status = lttng_trace_chunk_unlink_file(
				chunk, index_file_path);
		if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK &&
				!(chunk_status == LTTNG_TRACE_CHUNK_STATUS_ERROR &&
						errno == ENOENT)) {
			goto error;
		}
	}

	chunk_status = lttng_trace_chunk_open_file(chunk, index_file_path,
			flags, mode, &fd);
	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
		goto error;
	}

	ctf_packet_index_file_hdr_init(&hdr, index_major, index_minor);
	size_ret = lttng_write(fd, &hdr, sizeof(hdr));
	if (size_ret < sizeof(hdr)) {
		PERROR("Failed to write index header");
		goto error;
	}
	index_file->fd = fd;
	index_file->major = index_major;
	index_file->minor = index_minor;
	index_file->element_len = element_len;
	urcu_ref_init(&index_file->ref);

	return index_file;

error:
	if (fd >= 0) {
		ret = close(fd);
		if (ret < 0) {
			PERROR("Failed to close file descriptor of index file");
		}
	}
	free(index_file);
	return NULL;
}

struct lttng_index_file *lttng_index_file_create_from_trace_chunk(
		struct lttng_trace_chunk *chunk,
		const char *channel_path, const char *stream_name,
		uint64_t stream_file_size, uint64_t stream_file_index,
		uint32_t index_major, uint32_t index_minor,
		bool unlink_existing_file)
{
	return _lttng_index_file_create_from_trace_chunk(chunk, channel_path,
			stream_name, stream_file_size, stream_file_index,
			index_major, index_minor, unlink_existing_file,
			WRITE_FILE_FLAGS);
}

struct lttng_index_file *lttng_index_file_create_from_trace_chunk_read_only(
		struct lttng_trace_chunk *chunk,
		const char *channel_path, const char *stream_name,
		uint64_t stream_file_size, uint64_t stream_file_index,
		uint32_t index_major, uint32_t index_minor)
{
	return _lttng_index_file_create_from_trace_chunk(chunk, channel_path,
			stream_name, stream_file_size, stream_file_index,
			index_major, index_minor, false,
			READ_ONLY_FILE_FLAGS);
}

/*
 * Write index values to the given index file.
 *
 * Return 0 on success, -1 on error.
 */
int lttng_index_file_write(const struct lttng_index_file *index_file,
		const struct ctf_packet_index *element)
{
	int fd;
	size_t len;
	ssize_t ret;

	assert(index_file);
	assert(element);

	fd = index_file->fd;
	len = index_file->element_len;

	if (fd < 0) {
		goto error;
	}

	ret = lttng_write(fd, element, len);
	if (ret < len) {
		PERROR("writing index file");
		goto error;
	}
	return 0;

error:
	return -1;
}

/*
 * Read index values from the given index file.
 *
 * Return 0 on success, -1 on error.
 */
int lttng_index_file_read(const struct lttng_index_file *index_file,
		struct ctf_packet_index *element)
{
	ssize_t ret;
	int fd = index_file->fd;
	size_t len = index_file->element_len;

	assert(element);

	if (fd < 0) {
		goto error;
	}

	ret = lttng_read(fd, element, len);
	if (ret < 0) {
		PERROR("read index file");
		goto error;
	}
	if (ret < len) {
		ERR("lttng_read expected %zu, returned %zd", len, ret);
		goto error;
	}
	return 0;

error:
	return -1;
}

void lttng_index_file_get(struct lttng_index_file *index_file)
{
	urcu_ref_get(&index_file->ref);
}

static void lttng_index_file_release(struct urcu_ref *ref)
{
	struct lttng_index_file *index_file = caa_container_of(ref,
			struct lttng_index_file, ref);

	if (close(index_file->fd)) {
		PERROR("close index fd");
	}
	lttng_trace_chunk_put(index_file->trace_chunk);
	free(index_file);
}

void lttng_index_file_put(struct lttng_index_file *index_file)
{
	urcu_ref_put(&index_file->ref, lttng_index_file_release);
}
Commit	Line	Data
309167d2 JD	1	/*
	2	* Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
	3	* David Goulet <dgoulet@efficios.com>
f8f3885c	4	* 2016 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
309167d2 JD	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License, version 2 only, as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along with
	16	* this program; if not, write to the Free Software Foundation, Inc., 51
	17	* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	18	*/
	19
6c1c0768	20	#define _LGPL_SOURCE
309167d2	21	#include <assert.h>
1c20f0e2	22	#include <sys/stat.h>
2f8f53af DG	23	#include <sys/types.h>
2f8f53af DG	24	#include <fcntl.h>
309167d2	25
d2956687	26	#include <lttng/constant.h>
309167d2 JD	27	#include <common/common.h>
309167d2 JD	28	#include <common/defaults.h>
f263b7fd	29	#include <common/compat/endian.h>
309167d2 JD	30	#include <common/utils.h>
	31
	32	#include "index.h"
	33
2ef0da38	34	#define WRITE_FILE_FLAGS (O_WRONLY \| O_CREAT \| O_TRUNC)
ebb29c10 JG	35	#define READ_ONLY_FILE_FLAGS O_RDONLY
	36
	37	static struct lttng_index_file *_lttng_index_file_create_from_trace_chunk(
d2956687	38	struct lttng_trace_chunk *chunk,
ebb29c10	39	const char channel_path, const char stream_name,
c35f9726	40	uint64_t stream_file_size, uint64_t stream_file_index,
d2956687	41	uint32_t index_major, uint32_t index_minor,
ebb29c10 JG	42	bool unlink_existing_file,
ebb29c10 JG	43	int flags)
d2956687 JG	44	{
	45	struct lttng_index_file *index_file;
	46	enum lttng_trace_chunk_status chunk_status;
	47	int ret, fd = -1;
	48	ssize_t size_ret;
	49	struct ctf_packet_index_file_hdr hdr;
	50	char index_directory_path[LTTNG_PATH_MAX];
	51	char index_file_path[LTTNG_PATH_MAX];
	52	const uint32_t element_len = ctf_packet_index_len(index_major,
	53	index_minor);
d2956687	54	const mode_t mode = S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP;
ebb29c10	55	const bool acquired_reference = lttng_trace_chunk_get(chunk);
c35f9726 JG	56
c35f9726 JG	57	assert(acquired_reference);
d2956687 JG	58
	59	index_file = zmalloc(sizeof(*index_file));
	60	if (!index_file) {
	61	PERROR("Failed to allocate lttng_index_file");
	62	goto error;
	63	}
	64
c35f9726	65	index_file->trace_chunk = chunk;
d2956687 JG	66	ret = snprintf(index_directory_path, sizeof(index_directory_path),
	67	"%s/" DEFAULT_INDEX_DIR, channel_path);
	68	if (ret < 0 \|\| ret >= sizeof(index_directory_path)) {
	69	ERR("Failed to format index directory path");
	70	goto error;
	71	}
	72
	73	ret = utils_stream_file_path(index_directory_path, stream_name,
c35f9726	74	stream_file_size, stream_file_index,
d2956687 JG	75	DEFAULT_INDEX_FILE_SUFFIX,
	76	index_file_path, sizeof(index_file_path));
	77	if (ret) {
	78	goto error;
	79	}
	80
	81	if (unlink_existing_file) {
	82	/*
	83	* For tracefile rotation. We need to unlink the old
	84	* file if present to synchronize with the tail of the
	85	* live viewer which could be working on this same file.
	86	* By doing so, any reference to the old index file
	87	* stays valid even if we re-create a new file with the
	88	* same name afterwards.
	89	*/
348a81dc JG	90	chunk_status = lttng_trace_chunk_unlink_file(
	91	chunk, index_file_path);
	92	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK &&
	93	!(chunk_status == LTTNG_TRACE_CHUNK_STATUS_ERROR &&
	94	errno == ENOENT)) {
d2956687 JG	95	goto error;
d2956687 JG	96	}
348a81dc	97	}
d2956687 JG	98
	99	chunk_status = lttng_trace_chunk_open_file(chunk, index_file_path,
	100	flags, mode, &fd);
	101	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
	102	goto error;
	103	}
	104
	105	ctf_packet_index_file_hdr_init(&hdr, index_major, index_minor);
	106	size_ret = lttng_write(fd, &hdr, sizeof(hdr));
	107	if (size_ret < sizeof(hdr)) {
	108	PERROR("Failed to write index header");
	109	goto error;
	110	}
	111	index_file->fd = fd;
	112	index_file->major = index_major;
	113	index_file->minor = index_minor;
	114	index_file->element_len = element_len;
	115	urcu_ref_init(&index_file->ref);
	116
	117	return index_file;
	118
	119	error:
	120	if (fd >= 0) {
	121	ret = close(fd);
	122	if (ret < 0) {
	123	PERROR("Failed to close file descriptor of index file");
	124	}
	125	}
	126	free(index_file);
	127	return NULL;
	128	}
	129
ebb29c10 JG	130	struct lttng_index_file *lttng_index_file_create_from_trace_chunk(
	131	struct lttng_trace_chunk *chunk,
	132	const char channel_path, const char stream_name,
	133	uint64_t stream_file_size, uint64_t stream_file_index,
	134	uint32_t index_major, uint32_t index_minor,
	135	bool unlink_existing_file)
	136	{
	137	return _lttng_index_file_create_from_trace_chunk(chunk, channel_path,
	138	stream_name, stream_file_size, stream_file_index,
	139	index_major, index_minor, unlink_existing_file,
	140	WRITE_FILE_FLAGS);
	141	}
	142
	143	struct lttng_index_file *lttng_index_file_create_from_trace_chunk_read_only(
	144	struct lttng_trace_chunk *chunk,
	145	const char channel_path, const char stream_name,
	146	uint64_t stream_file_size, uint64_t stream_file_index,
	147	uint32_t index_major, uint32_t index_minor)
	148	{
	149	return _lttng_index_file_create_from_trace_chunk(chunk, channel_path,
	150	stream_name, stream_file_size, stream_file_index,
	151	index_major, index_minor, false,
	152	READ_ONLY_FILE_FLAGS);
	153	}
	154
309167d2	155	/*
f8f3885c	156	* Write index values to the given index file.
309167d2	157	*
f8f3885c	158	* Return 0 on success, -1 on error.
309167d2	159	*/
f8f3885c MD	160	int lttng_index_file_write(const struct lttng_index_file *index_file,
f8f3885c MD	161	const struct ctf_packet_index *element)
309167d2	162	{
0b0ac4a9 JR	163	int fd;
0b0ac4a9 JR	164	size_t len;
6cd525e8	165	ssize_t ret;
309167d2	166
0b0ac4a9	167	assert(index_file);
f8f3885c	168	assert(element);
309167d2	169
0b0ac4a9 JR	170	fd = index_file->fd;
	171	len = index_file->element_len;
	172
183f6fa2	173	if (fd < 0) {
183f6fa2 DG	174	goto error;
	175	}
	176
f8f3885c	177	ret = lttng_write(fd, element, len);
6cd525e8	178	if (ret < len) {
309167d2	179	PERROR("writing index file");
f8f3885c MD	180	goto error;
	181	}
	182	return 0;
	183
	184	error:
	185	return -1;
	186	}
	187
	188	/*
	189	* Read index values from the given index file.
	190	*
	191	* Return 0 on success, -1 on error.
	192	*/
	193	int lttng_index_file_read(const struct lttng_index_file *index_file,
	194	struct ctf_packet_index *element)
	195	{
	196	ssize_t ret;
	197	int fd = index_file->fd;
	198	size_t len = index_file->element_len;
	199
	200	assert(element);
	201
	202	if (fd < 0) {
	203	goto error;
	204	}
	205
	206	ret = lttng_read(fd, element, len);
2239b15a	207	if (ret < 0) {
f8f3885c MD	208	PERROR("read index file");
f8f3885c MD	209	goto error;
309167d2	210	}
2239b15a MD	211	if (ret < len) {
	212	ERR("lttng_read expected %zu, returned %zd", len, ret);
	213	goto error;
	214	}
f8f3885c	215	return 0;
309167d2	216
183f6fa2	217	error:
f8f3885c	218	return -1;
309167d2	219	}
2f8f53af	220
f8f3885c MD	221	void lttng_index_file_get(struct lttng_index_file *index_file)
	222	{
	223	urcu_ref_get(&index_file->ref);
	224	}
	225
	226	static void lttng_index_file_release(struct urcu_ref *ref)
	227	{
	228	struct lttng_index_file *index_file = caa_container_of(ref,
	229	struct lttng_index_file, ref);
	230
	231	if (close(index_file->fd)) {
	232	PERROR("close index fd");
	233	}
c35f9726	234	lttng_trace_chunk_put(index_file->trace_chunk);
f8f3885c MD	235	free(index_file);
	236	}
	237
	238	void lttng_index_file_put(struct lttng_index_file *index_file)
	239	{
	240	urcu_ref_put(&index_file->ref, lttng_index_file_release);
2f8f53af	241	}