src/common/index/index.c

   1 /*
   2  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   3  *                      David Goulet <dgoulet@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License, version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 51
  16  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <assert.h>
  21 #include <sys/stat.h>
  22
  23 #include <common/common.h>
  24 #include <common/defaults.h>
  25 #include <common/utils.h>
  26
  27 #include "index.h"
  28
  29 /*
  30  * Create the index file associated with a trace file.
  31  *
  32  * Return fd on success, a negative value on error.
  33  */
  34 int index_create_file(char *path_name, char *stream_name, int uid, int gid,
  35                 uint64_t size, uint64_t count)
  36 {
  37         int ret, fd = -1;
  38         ssize_t size_ret;
  39         struct lttng_packet_index_file_hdr hdr;
  40         char fullpath[PATH_MAX];
  41
  42         ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR,
  43                         path_name);
  44         if (ret < 0) {
  45                 PERROR("snprintf index path");
  46                 goto error;
  47         }
  48
  49         /* Create index directory if necessary. */
  50         ret = run_as_mkdir(fullpath, S_IRWXU | S_IRWXG, uid, gid);
  51         if (ret < 0) {
  52                 if (ret != -EEXIST) {
  53                         ERR("Index trace directory creation error");
  54                         goto error;
  55                 }
  56         }
  57
  58         ret = utils_create_stream_file(fullpath, stream_name, size, count, uid,
  59                         gid, DEFAULT_INDEX_FILE_SUFFIX);
  60         if (ret < 0) {
  61                 goto error;
  62         }
  63         fd = ret;
  64
  65         memcpy(hdr.magic, INDEX_MAGIC, sizeof(hdr.magic));
  66         hdr.index_major = htobe32(INDEX_MAJOR);
  67         hdr.index_minor = htobe32(INDEX_MINOR);
  68
  69         size_ret = lttng_write(fd, &hdr, sizeof(hdr));
  70         if (size_ret < sizeof(hdr)) {
  71                 PERROR("write index header");
  72                 ret = -1;
  73                 goto error;
  74         }
  75
  76         return fd;
  77
  78 error:
  79         if (fd >= 0) {
  80                 int close_ret;
  81
  82                 close_ret = close(fd);
  83                 if (close_ret < 0) {
  84                         PERROR("close index fd");
  85                 }
  86         }
  87         return ret;
  88 }
  89
  90 /*
  91  * Write index values to the given fd of size len.
  92  *
  93  * Return "len" on success or else < len on error. errno contains error
  94  * details.
  95  */
  96 ssize_t index_write(int fd, struct lttng_packet_index *index, size_t len)
  97 {
  98         ssize_t ret;
  99
 100         assert(fd >= 0);
 101         assert(index);
 102
 103         ret = lttng_write(fd, index, len);
 104         if (ret < len) {
 105                 PERROR("writing index file");
 106         }
 107
 108         return ret;
 109 }