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#include <linux/compiler.h>
#include <linux/kernel.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include "data.h"
#include "util.h"
#include "debug.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;
char sbuf[STRERR_BUFSIZE];
fd = open(file->path, O_RDONLY);
if (fd < 0) {
int err = errno;
pr_err("failed to open %s: %s", file->path,
str_error_r(err, sbuf, sizeof(sbuf)));
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 (use -f to override)\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)
{
int fd;
char sbuf[STRERR_BUFSIZE];
if (check_backup(file))
return -1;
fd = open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
if (fd < 0)
pr_err("failed to open %s : %s\n", file->path,
str_error_r(errno, sbuf, sizeof(sbuf)));
return fd;
}
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);
}
ssize_t perf_data_file__write(struct perf_data_file *file,
void *buf, size_t size)
{
return writen(file->fd, buf, size);
}
int perf_data_file__switch(struct perf_data_file *file,
const char *postfix,
size_t pos, bool at_exit)
{
char *new_filepath;
int ret;
if (check_pipe(file))
return -EINVAL;
if (perf_data_file__is_read(file))
return -EINVAL;
if (asprintf(&new_filepath, "%s.%s", file->path, postfix) < 0)
return -ENOMEM;
/*
* Only fire a warning, don't return error, continue fill
* original file.
*/
if (rename(file->path, new_filepath))
pr_warning("Failed to rename %s to %s\n", file->path, new_filepath);
if (!at_exit) {
close(file->fd);
ret = perf_data_file__open(file);
if (ret < 0)
goto out;
if (lseek(file->fd, pos, SEEK_SET) == (off_t)-1) {
ret = -errno;
pr_debug("Failed to lseek to %zu: %s",
pos, strerror(errno));
goto out;
}
}
ret = file->fd;
out:
free(new_filepath);
return ret;
}
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