#include <linux/compiler.h>#include <linux/kernel.h>#include <sys/types.h>#include <sys/stat.h>#include <unistd.h>#include <string.h> #include "data.h"#include "util.h" static bool check_pipe(struct perf_data_file *file){	struct stat st;	bool is_pipe = false;	int fd = perf_data_file__is_read(file) ?		 STDIN_FILENO : STDOUT_FILENO; 	if (!file->path) {		if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))			is_pipe = true;	} else {		if (!strcmp(file->path, "-"))			is_pipe = true;	} 	if (is_pipe)		file->fd = fd; 	return file->is_pipe = is_pipe;} static int check_backup(struct perf_data_file *file){	struct stat st; 	if (!stat(file->path, &st) && st.st_size) {		/* TODO check errors properly */		char oldname[PATH_MAX];		snprintf(oldname, sizeof(oldname), "%s.old",			 file->path);		unlink(oldname);		rename(file->path, oldname);	} 	return 0;} static int open_file_read(struct perf_data_file *file){	struct stat st;	int fd; 	fd = open(file->path, O_RDONLY);	if (fd < 0) {		int err = errno; 		pr_err("failed to open %s: %s", file->path, strerror(err));		if (err == ENOENT && !strcmp(file->path, "perf.data"))			pr_err("  (try 'perf record' first)");		pr_err("\n");		return -err;	} 	if (fstat(fd, &st) < 0)		goto out_close; 	if (!file->force && st.st_uid && (st.st_uid != geteuid())) {		pr_err("file %s not owned by current user or root\n",		       file->path);		goto out_close;	} 	if (!st.st_size) {		pr_info("zero-sized file (%s), nothing to do!\n",			file->path);		goto out_close;	} 	file->size = st.st_size;	return fd;  out_close:	close(fd);	return -1;} static int open_file_write(struct perf_data_file *file){	if (check_backup(file))		return -1; 	return open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);} static int open_file(struct perf_data_file *file){	int fd; 	fd = perf_data_file__is_read(file) ?	     open_file_read(file) : open_file_write(file); 	file->fd = fd;	return fd < 0 ? -1 : 0;} int perf_data_file__open(struct perf_data_file *file){	if (check_pipe(file))		return 0; 	if (!file->path)		file->path = "perf.data"; 	return open_file(file);} void perf_data_file__close(struct perf_data_file *file){	close(file->fd);}