xref: /linux/tools/perf/util/data.c (revision 44f57d78) 
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/compiler.h>
3 #include <linux/kernel.h>
4 #include <sys/types.h>
5 #include <sys/stat.h>
6 #include <errno.h>
7 #include <fcntl.h>
8 #include <unistd.h>
9 #include <string.h>
10 #include <asm/bug.h>
11 #include <sys/types.h>
12 #include <dirent.h>
13 
14 #include "data.h"
15 #include "util.h"
16 #include "debug.h"
17 #include "header.h"
18 
19 static void close_dir(struct perf_data_file *files, int nr)
20 {
21 	while (--nr >= 1) {
22 		close(files[nr].fd);
23 		free(files[nr].path);
24 	}
25 	free(files);
26 }
27 
28 void perf_data__close_dir(struct perf_data *data)
29 {
30 	close_dir(data->dir.files, data->dir.nr);
31 }
32 
33 int perf_data__create_dir(struct perf_data *data, int nr)
34 {
35 	struct perf_data_file *files = NULL;
36 	int i, ret = -1;
37 
38 	if (WARN_ON(!data->is_dir))
39 		return -EINVAL;
40 
41 	files = zalloc(nr * sizeof(*files));
42 	if (!files)
43 		return -ENOMEM;
44 
45 	data->dir.version = PERF_DIR_VERSION;
46 	data->dir.files   = files;
47 	data->dir.nr      = nr;
48 
49 	for (i = 0; i < nr; i++) {
50 		struct perf_data_file *file = &files[i];
51 
52 		if (asprintf(&file->path, "%s/data.%d", data->path, i) < 0)
53 			goto out_err;
54 
55 		ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
56 		if (ret < 0)
57 			goto out_err;
58 
59 		file->fd = ret;
60 	}
61 
62 	return 0;
63 
64 out_err:
65 	close_dir(files, i);
66 	return ret;
67 }
68 
69 int perf_data__open_dir(struct perf_data *data)
70 {
71 	struct perf_data_file *files = NULL;
72 	struct dirent *dent;
73 	int ret = -1;
74 	DIR *dir;
75 	int nr = 0;
76 
77 	if (WARN_ON(!data->is_dir))
78 		return -EINVAL;
79 
80 	/* The version is provided by DIR_FORMAT feature. */
81 	if (WARN_ON(data->dir.version != PERF_DIR_VERSION))
82 		return -1;
83 
84 	dir = opendir(data->path);
85 	if (!dir)
86 		return -EINVAL;
87 
88 	while ((dent = readdir(dir)) != NULL) {
89 		struct perf_data_file *file;
90 		char path[PATH_MAX];
91 		struct stat st;
92 
93 		snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name);
94 		if (stat(path, &st))
95 			continue;
96 
97 		if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data", 4))
98 			continue;
99 
100 		ret = -ENOMEM;
101 
102 		file = realloc(files, (nr + 1) * sizeof(*files));
103 		if (!file)
104 			goto out_err;
105 
106 		files = file;
107 		file = &files[nr++];
108 
109 		file->path = strdup(path);
110 		if (!file->path)
111 			goto out_err;
112 
113 		ret = open(file->path, O_RDONLY);
114 		if (ret < 0)
115 			goto out_err;
116 
117 		file->fd = ret;
118 		file->size = st.st_size;
119 	}
120 
121 	if (!files)
122 		return -EINVAL;
123 
124 	data->dir.files = files;
125 	data->dir.nr    = nr;
126 	return 0;
127 
128 out_err:
129 	close_dir(files, nr);
130 	return ret;
131 }
132 
133 int perf_data__update_dir(struct perf_data *data)
134 {
135 	int i;
136 
137 	if (WARN_ON(!data->is_dir))
138 		return -EINVAL;
139 
140 	for (i = 0; i < data->dir.nr; i++) {
141 		struct perf_data_file *file = &data->dir.files[i];
142 		struct stat st;
143 
144 		if (fstat(file->fd, &st))
145 			return -1;
146 
147 		file->size = st.st_size;
148 	}
149 
150 	return 0;
151 }
152 
153 static bool check_pipe(struct perf_data *data)
154 {
155 	struct stat st;
156 	bool is_pipe = false;
157 	int fd = perf_data__is_read(data) ?
158 		 STDIN_FILENO : STDOUT_FILENO;
159 
160 	if (!data->path) {
161 		if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
162 			is_pipe = true;
163 	} else {
164 		if (!strcmp(data->path, "-"))
165 			is_pipe = true;
166 	}
167 
168 	if (is_pipe)
169 		data->file.fd = fd;
170 
171 	return data->is_pipe = is_pipe;
172 }
173 
174 static int check_backup(struct perf_data *data)
175 {
176 	struct stat st;
177 
178 	if (perf_data__is_read(data))
179 		return 0;
180 
181 	if (!stat(data->path, &st) && st.st_size) {
182 		char oldname[PATH_MAX];
183 		int ret;
184 
185 		snprintf(oldname, sizeof(oldname), "%s.old",
186 			 data->path);
187 
188 		ret = rm_rf_perf_data(oldname);
189 		if (ret) {
190 			pr_err("Can't remove old data: %s (%s)\n",
191 			       ret == -2 ?
192 			       "Unknown file found" : strerror(errno),
193 			       oldname);
194 			return -1;
195 		}
196 
197 		if (rename(data->path, oldname)) {
198 			pr_err("Can't move data: %s (%s to %s)\n",
199 			       strerror(errno),
200 			       data->path, oldname);
201 			return -1;
202 		}
203 	}
204 
205 	return 0;
206 }
207 
208 static bool is_dir(struct perf_data *data)
209 {
210 	struct stat st;
211 
212 	if (stat(data->path, &st))
213 		return false;
214 
215 	return (st.st_mode & S_IFMT) == S_IFDIR;
216 }
217 
218 static int open_file_read(struct perf_data *data)
219 {
220 	struct stat st;
221 	int fd;
222 	char sbuf[STRERR_BUFSIZE];
223 
224 	fd = open(data->file.path, O_RDONLY);
225 	if (fd < 0) {
226 		int err = errno;
227 
228 		pr_err("failed to open %s: %s", data->file.path,
229 			str_error_r(err, sbuf, sizeof(sbuf)));
230 		if (err == ENOENT && !strcmp(data->file.path, "perf.data"))
231 			pr_err("  (try 'perf record' first)");
232 		pr_err("\n");
233 		return -err;
234 	}
235 
236 	if (fstat(fd, &st) < 0)
237 		goto out_close;
238 
239 	if (!data->force && st.st_uid && (st.st_uid != geteuid())) {
240 		pr_err("File %s not owned by current user or root (use -f to override)\n",
241 		       data->file.path);
242 		goto out_close;
243 	}
244 
245 	if (!st.st_size) {
246 		pr_info("zero-sized data (%s), nothing to do!\n",
247 			data->file.path);
248 		goto out_close;
249 	}
250 
251 	data->file.size = st.st_size;
252 	return fd;
253 
254  out_close:
255 	close(fd);
256 	return -1;
257 }
258 
259 static int open_file_write(struct perf_data *data)
260 {
261 	int fd;
262 	char sbuf[STRERR_BUFSIZE];
263 
264 	fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,
265 		  S_IRUSR|S_IWUSR);
266 
267 	if (fd < 0)
268 		pr_err("failed to open %s : %s\n", data->file.path,
269 			str_error_r(errno, sbuf, sizeof(sbuf)));
270 
271 	return fd;
272 }
273 
274 static int open_file(struct perf_data *data)
275 {
276 	int fd;
277 
278 	fd = perf_data__is_read(data) ?
279 	     open_file_read(data) : open_file_write(data);
280 
281 	if (fd < 0) {
282 		zfree(&data->file.path);
283 		return -1;
284 	}
285 
286 	data->file.fd = fd;
287 	return 0;
288 }
289 
290 static int open_file_dup(struct perf_data *data)
291 {
292 	data->file.path = strdup(data->path);
293 	if (!data->file.path)
294 		return -ENOMEM;
295 
296 	return open_file(data);
297 }
298 
299 static int open_dir(struct perf_data *data)
300 {
301 	int ret;
302 
303 	/*
304 	 * So far we open only the header, so we can read the data version and
305 	 * layout.
306 	 */
307 	if (asprintf(&data->file.path, "%s/header", data->path) < 0)
308 		return -1;
309 
310 	if (perf_data__is_write(data) &&
311 	    mkdir(data->path, S_IRWXU) < 0)
312 		return -1;
313 
314 	ret = open_file(data);
315 
316 	/* Cleanup whatever we managed to create so far. */
317 	if (ret && perf_data__is_write(data))
318 		rm_rf_perf_data(data->path);
319 
320 	return ret;
321 }
322 
323 int perf_data__open(struct perf_data *data)
324 {
325 	if (check_pipe(data))
326 		return 0;
327 
328 	if (!data->path)
329 		data->path = "perf.data";
330 
331 	if (check_backup(data))
332 		return -1;
333 
334 	if (perf_data__is_read(data))
335 		data->is_dir = is_dir(data);
336 
337 	return perf_data__is_dir(data) ?
338 	       open_dir(data) : open_file_dup(data);
339 }
340 
341 void perf_data__close(struct perf_data *data)
342 {
343 	if (perf_data__is_dir(data))
344 		perf_data__close_dir(data);
345 
346 	zfree(&data->file.path);
347 	close(data->file.fd);
348 }
349 
350 ssize_t perf_data_file__write(struct perf_data_file *file,
351 			      void *buf, size_t size)
352 {
353 	return writen(file->fd, buf, size);
354 }
355 
356 ssize_t perf_data__write(struct perf_data *data,
357 			      void *buf, size_t size)
358 {
359 	return perf_data_file__write(&data->file, buf, size);
360 }
361 
362 int perf_data__switch(struct perf_data *data,
363 			   const char *postfix,
364 			   size_t pos, bool at_exit,
365 			   char **new_filepath)
366 {
367 	int ret;
368 
369 	if (check_pipe(data))
370 		return -EINVAL;
371 	if (perf_data__is_read(data))
372 		return -EINVAL;
373 
374 	if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
375 		return -ENOMEM;
376 
377 	/*
378 	 * Only fire a warning, don't return error, continue fill
379 	 * original file.
380 	 */
381 	if (rename(data->path, *new_filepath))
382 		pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
383 
384 	if (!at_exit) {
385 		close(data->file.fd);
386 		ret = perf_data__open(data);
387 		if (ret < 0)
388 			goto out;
389 
390 		if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
391 			ret = -errno;
392 			pr_debug("Failed to lseek to %zu: %s",
393 				 pos, strerror(errno));
394 			goto out;
395 		}
396 	}
397 	ret = data->file.fd;
398 out:
399 	return ret;
400 }
401 
402 unsigned long perf_data__size(struct perf_data *data)
403 {
404 	u64 size = data->file.size;
405 	int i;
406 
407 	if (!data->is_dir)
408 		return size;
409 
410 	for (i = 0; i < data->dir.nr; i++) {
411 		struct perf_data_file *file = &data->dir.files[i];
412 
413 		size += file->size;
414 	}
415 
416 	return size;
417 }
418