tools/perf/util/data.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/compiler.h>
   3 #include <linux/kernel.h>
   4 #include <linux/zalloc.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <errno.h>
   8 #include <fcntl.h>
   9 #include <unistd.h>
  10 #include <string.h>
  11 #include <asm/bug.h>
  12 #include <sys/types.h>
  13 #include <dirent.h>
  14
  15 #include "data.h"
  16 #include "util.h"
  17 #include "debug.h"
  18 #include "header.h"
  19
  20 static void close_dir(struct perf_data_file *files, int nr)
  21 {
  22         while (--nr >= 1) {
  23                 close(files[nr].fd);
  24                 zfree(&files[nr].path);
  25         }
  26         free(files);
  27 }
  28
  29 void perf_data__close_dir(struct perf_data *data)
  30 {
  31         close_dir(data->dir.files, data->dir.nr);
  32 }
  33
  34 int perf_data__create_dir(struct perf_data *data, int nr)
  35 {
  36         struct perf_data_file *files = NULL;
  37         int i, ret = -1;
  38
  39         if (WARN_ON(!data->is_dir))
  40                 return -EINVAL;
  41
  42         files = zalloc(nr * sizeof(*files));
  43         if (!files)
  44                 return -ENOMEM;
  45
  46         data->dir.version = PERF_DIR_VERSION;
  47         data->dir.files   = files;
  48         data->dir.nr      = nr;
  49
  50         for (i = 0; i < nr; i++) {
  51                 struct perf_data_file *file = &files[i];
  52
  53                 if (asprintf(&file->path, "%s/data.%d", data->path, i) < 0)
  54                         goto out_err;
  55
  56                 ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
  57                 if (ret < 0)
  58                         goto out_err;
  59
  60                 file->fd = ret;
  61         }
  62
  63         return 0;
  64
  65 out_err:
  66         close_dir(files, i);
  67         return ret;
  68 }
  69
  70 int perf_data__open_dir(struct perf_data *data)
  71 {
  72         struct perf_data_file *files = NULL;
  73         struct dirent *dent;
  74         int ret = -1;
  75         DIR *dir;
  76         int nr = 0;
  77
  78         if (WARN_ON(!data->is_dir))
  79                 return -EINVAL;
  80
  81         /* The version is provided by DIR_FORMAT feature. */
  82         if (WARN_ON(data->dir.version != PERF_DIR_VERSION))
  83                 return -1;
  84
  85         dir = opendir(data->path);
  86         if (!dir)
  87                 return -EINVAL;
  88
  89         while ((dent = readdir(dir)) != NULL) {
  90                 struct perf_data_file *file;
  91                 char path[PATH_MAX];
  92                 struct stat st;
  93
  94                 snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name);
  95                 if (stat(path, &st))
  96                         continue;
  97
  98                 if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data", 4))
  99                         continue;
 100
 101                 ret = -ENOMEM;
 102
 103                 file = realloc(files, (nr + 1) * sizeof(*files));
 104                 if (!file)
 105                         goto out_err;
 106
 107                 files = file;
 108                 file = &files[nr++];
 109
 110                 file->path = strdup(path);
 111                 if (!file->path)
 112                         goto out_err;
 113
 114                 ret = open(file->path, O_RDONLY);
 115                 if (ret < 0)
 116                         goto out_err;
 117
 118                 file->fd = ret;
 119                 file->size = st.st_size;
 120         }
 121
 122         if (!files)
 123                 return -EINVAL;
 124
 125         data->dir.files = files;
 126         data->dir.nr    = nr;
 127         return 0;
 128
 129 out_err:
 130         close_dir(files, nr);
 131         return ret;
 132 }
 133
 134 int perf_data__update_dir(struct perf_data *data)
 135 {
 136         int i;
 137
 138         if (WARN_ON(!data->is_dir))
 139                 return -EINVAL;
 140
 141         for (i = 0; i < data->dir.nr; i++) {
 142                 struct perf_data_file *file = &data->dir.files[i];
 143                 struct stat st;
 144
 145                 if (fstat(file->fd, &st))
 146                         return -1;
 147
 148                 file->size = st.st_size;
 149         }
 150
 151         return 0;
 152 }
 153
 154 static bool check_pipe(struct perf_data *data)
 155 {
 156         struct stat st;
 157         bool is_pipe = false;
 158         int fd = perf_data__is_read(data) ?
 159                  STDIN_FILENO : STDOUT_FILENO;
 160
 161         if (!data->path) {
 162                 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
 163                         is_pipe = true;
 164         } else {
 165                 if (!strcmp(data->path, "-"))
 166                         is_pipe = true;
 167         }
 168
 169         if (is_pipe)
 170                 data->file.fd = fd;
 171
 172         return data->is_pipe = is_pipe;
 173 }
 174
 175 static int check_backup(struct perf_data *data)
 176 {
 177         struct stat st;
 178
 179         if (perf_data__is_read(data))
 180                 return 0;
 181
 182         if (!stat(data->path, &st) && st.st_size) {
 183                 char oldname[PATH_MAX];
 184                 int ret;
 185
 186                 snprintf(oldname, sizeof(oldname), "%s.old",
 187                          data->path);
 188
 189                 ret = rm_rf_perf_data(oldname);
 190                 if (ret) {
 191                         pr_err("Can't remove old data: %s (%s)\n",
 192                                ret == -2 ?
 193                                "Unknown file found" : strerror(errno),
 194                                oldname);
 195                         return -1;
 196                 }
 197
 198                 if (rename(data->path, oldname)) {
 199                         pr_err("Can't move data: %s (%s to %s)\n",
 200                                strerror(errno),
 201                                data->path, oldname);
 202                         return -1;
 203                 }
 204         }
 205
 206         return 0;
 207 }
 208
 209 static bool is_dir(struct perf_data *data)
 210 {
 211         struct stat st;
 212
 213         if (stat(data->path, &st))
 214                 return false;
 215
 216         return (st.st_mode & S_IFMT) == S_IFDIR;
 217 }
 218
 219 static int open_file_read(struct perf_data *data)
 220 {
 221         struct stat st;
 222         int fd;
 223         char sbuf[STRERR_BUFSIZE];
 224
 225         fd = open(data->file.path, O_RDONLY);
 226         if (fd < 0) {
 227                 int err = errno;
 228
 229                 pr_err("failed to open %s: %s", data->file.path,
 230                         str_error_r(err, sbuf, sizeof(sbuf)));
 231                 if (err == ENOENT && !strcmp(data->file.path, "perf.data"))
 232                         pr_err("  (try 'perf record' first)");
 233                 pr_err("\n");
 234                 return -err;
 235         }
 236
 237         if (fstat(fd, &st) < 0)
 238                 goto out_close;
 239
 240         if (!data->force && st.st_uid && (st.st_uid != geteuid())) {
 241                 pr_err("File %s not owned by current user or root (use -f to override)\n",
 242                        data->file.path);
 243                 goto out_close;
 244         }
 245
 246         if (!st.st_size) {
 247                 pr_info("zero-sized data (%s), nothing to do!\n",
 248                         data->file.path);
 249                 goto out_close;
 250         }
 251
 252         data->file.size = st.st_size;
 253         return fd;
 254
 255  out_close:
 256         close(fd);
 257         return -1;
 258 }
 259
 260 static int open_file_write(struct perf_data *data)
 261 {
 262         int fd;
 263         char sbuf[STRERR_BUFSIZE];
 264
 265         fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,
 266                   S_IRUSR|S_IWUSR);
 267
 268         if (fd < 0)
 269                 pr_err("failed to open %s : %s\n", data->file.path,
 270                         str_error_r(errno, sbuf, sizeof(sbuf)));
 271
 272         return fd;
 273 }
 274
 275 static int open_file(struct perf_data *data)
 276 {
 277         int fd;
 278
 279         fd = perf_data__is_read(data) ?
 280              open_file_read(data) : open_file_write(data);
 281
 282         if (fd < 0) {
 283                 zfree(&data->file.path);
 284                 return -1;
 285         }
 286
 287         data->file.fd = fd;
 288         return 0;
 289 }
 290
 291 static int open_file_dup(struct perf_data *data)
 292 {
 293         data->file.path = strdup(data->path);
 294         if (!data->file.path)
 295                 return -ENOMEM;
 296
 297         return open_file(data);
 298 }
 299
 300 static int open_dir(struct perf_data *data)
 301 {
 302         int ret;
 303
 304         /*
 305          * So far we open only the header, so we can read the data version and
 306          * layout.
 307          */
 308         if (asprintf(&data->file.path, "%s/header", data->path) < 0)
 309                 return -1;
 310
 311         if (perf_data__is_write(data) &&
 312             mkdir(data->path, S_IRWXU) < 0)
 313                 return -1;
 314
 315         ret = open_file(data);
 316
 317         /* Cleanup whatever we managed to create so far. */
 318         if (ret && perf_data__is_write(data))
 319                 rm_rf_perf_data(data->path);
 320
 321         return ret;
 322 }
 323
 324 int perf_data__open(struct perf_data *data)
 325 {
 326         if (check_pipe(data))
 327                 return 0;
 328
 329         if (!data->path)
 330                 data->path = "perf.data";
 331
 332         if (check_backup(data))
 333                 return -1;
 334
 335         if (perf_data__is_read(data))
 336                 data->is_dir = is_dir(data);
 337
 338         return perf_data__is_dir(data) ?
 339                open_dir(data) : open_file_dup(data);
 340 }
 341
 342 void perf_data__close(struct perf_data *data)
 343 {
 344         if (perf_data__is_dir(data))
 345                 perf_data__close_dir(data);
 346
 347         zfree(&data->file.path);
 348         close(data->file.fd);
 349 }
 350
 351 ssize_t perf_data_file__write(struct perf_data_file *file,
 352                               void *buf, size_t size)
 353 {
 354         return writen(file->fd, buf, size);
 355 }
 356
 357 ssize_t perf_data__write(struct perf_data *data,
 358                               void *buf, size_t size)
 359 {
 360         return perf_data_file__write(&data->file, buf, size);
 361 }
 362
 363 int perf_data__switch(struct perf_data *data,
 364                            const char *postfix,
 365                            size_t pos, bool at_exit,
 366                            char **new_filepath)
 367 {
 368         int ret;
 369
 370         if (check_pipe(data))
 371                 return -EINVAL;
 372         if (perf_data__is_read(data))
 373                 return -EINVAL;
 374
 375         if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
 376                 return -ENOMEM;
 377
 378         /*
 379          * Only fire a warning, don't return error, continue fill
 380          * original file.
 381          */
 382         if (rename(data->path, *new_filepath))
 383                 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
 384
 385         if (!at_exit) {
 386                 close(data->file.fd);
 387                 ret = perf_data__open(data);
 388                 if (ret < 0)
 389                         goto out;
 390
 391                 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
 392                         ret = -errno;
 393                         pr_debug("Failed to lseek to %zu: %s",
 394                                  pos, strerror(errno));
 395                         goto out;
 396                 }
 397         }
 398         ret = data->file.fd;
 399 out:
 400         return ret;
 401 }
 402
 403 unsigned long perf_data__size(struct perf_data *data)
 404 {
 405         u64 size = data->file.size;
 406         int i;
 407
 408         if (!data->is_dir)
 409                 return size;
 410
 411         for (i = 0; i < data->dir.nr; i++) {
 412                 struct perf_data_file *file = &data->dir.files[i];
 413
 414                 size += file->size;
 415         }
 416
 417         return size;
 418 }