1 #include <linux/compiler.h> 2 #include <linux/kernel.h> 3 #include <sys/types.h> 4 #include <sys/stat.h> 5 #include <unistd.h> 6 #include <string.h> 7 8 #include "data.h" 9 #include "util.h" 10 #include "debug.h" 11 12 static bool check_pipe(struct perf_data_file *file) 13 { 14 struct stat st; 15 bool is_pipe = false; 16 int fd = perf_data_file__is_read(file) ? 17 STDIN_FILENO : STDOUT_FILENO; 18 19 if (!file->path) { 20 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode)) 21 is_pipe = true; 22 } else { 23 if (!strcmp(file->path, "-")) 24 is_pipe = true; 25 } 26 27 if (is_pipe) 28 file->fd = fd; 29 30 return file->is_pipe = is_pipe; 31 } 32 33 static int check_backup(struct perf_data_file *file) 34 { 35 struct stat st; 36 37 if (!stat(file->path, &st) && st.st_size) { 38 /* TODO check errors properly */ 39 char oldname[PATH_MAX]; 40 snprintf(oldname, sizeof(oldname), "%s.old", 41 file->path); 42 unlink(oldname); 43 rename(file->path, oldname); 44 } 45 46 return 0; 47 } 48 49 static int open_file_read(struct perf_data_file *file) 50 { 51 struct stat st; 52 int fd; 53 char sbuf[STRERR_BUFSIZE]; 54 55 fd = open(file->path, O_RDONLY); 56 if (fd < 0) { 57 int err = errno; 58 59 pr_err("failed to open %s: %s", file->path, 60 strerror_r(err, sbuf, sizeof(sbuf))); 61 if (err == ENOENT && !strcmp(file->path, "perf.data")) 62 pr_err(" (try 'perf record' first)"); 63 pr_err("\n"); 64 return -err; 65 } 66 67 if (fstat(fd, &st) < 0) 68 goto out_close; 69 70 if (!file->force && st.st_uid && (st.st_uid != geteuid())) { 71 pr_err("File %s not owned by current user or root (use -f to override)\n", 72 file->path); 73 goto out_close; 74 } 75 76 if (!st.st_size) { 77 pr_info("zero-sized file (%s), nothing to do!\n", 78 file->path); 79 goto out_close; 80 } 81 82 file->size = st.st_size; 83 return fd; 84 85 out_close: 86 close(fd); 87 return -1; 88 } 89 90 static int open_file_write(struct perf_data_file *file) 91 { 92 int fd; 93 char sbuf[STRERR_BUFSIZE]; 94 95 if (check_backup(file)) 96 return -1; 97 98 fd = open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR); 99 100 if (fd < 0) 101 pr_err("failed to open %s : %s\n", file->path, 102 strerror_r(errno, sbuf, sizeof(sbuf))); 103 104 return fd; 105 } 106 107 static int open_file(struct perf_data_file *file) 108 { 109 int fd; 110 111 fd = perf_data_file__is_read(file) ? 112 open_file_read(file) : open_file_write(file); 113 114 file->fd = fd; 115 return fd < 0 ? -1 : 0; 116 } 117 118 int perf_data_file__open(struct perf_data_file *file) 119 { 120 if (check_pipe(file)) 121 return 0; 122 123 if (!file->path) 124 file->path = "perf.data"; 125 126 return open_file(file); 127 } 128 129 void perf_data_file__close(struct perf_data_file *file) 130 { 131 close(file->fd); 132 } 133 134 ssize_t perf_data_file__write(struct perf_data_file *file, 135 void *buf, size_t size) 136 { 137 return writen(file->fd, buf, size); 138 } 139 140 int perf_data_file__switch(struct perf_data_file *file, 141 const char *postfix, 142 size_t pos, bool at_exit) 143 { 144 char *new_filepath; 145 int ret; 146 147 if (check_pipe(file)) 148 return -EINVAL; 149 if (perf_data_file__is_read(file)) 150 return -EINVAL; 151 152 if (asprintf(&new_filepath, "%s.%s", file->path, postfix) < 0) 153 return -ENOMEM; 154 155 /* 156 * Only fire a warning, don't return error, continue fill 157 * original file. 158 */ 159 if (rename(file->path, new_filepath)) 160 pr_warning("Failed to rename %s to %s\n", file->path, new_filepath); 161 162 if (!at_exit) { 163 close(file->fd); 164 ret = perf_data_file__open(file); 165 if (ret < 0) 166 goto out; 167 168 if (lseek(file->fd, pos, SEEK_SET) == (off_t)-1) { 169 ret = -errno; 170 pr_debug("Failed to lseek to %zu: %s", 171 pos, strerror(errno)); 172 goto out; 173 } 174 } 175 ret = file->fd; 176 out: 177 free(new_filepath); 178 return ret; 179 } 180