tar: report error if child dies while writing out the end of tarball

(e.g. out of disk space).

diff --git a/archival/tar.c b/archival/tar.c
index ba7cb0f..7465e88 100644 (file)
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -504,7 +504,6 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
                volatile int vfork_exec_errno = 0;
                char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
 
-
                if (pipe(gzipDataPipe) < 0 || pipe(gzipStatusPipe) < 0)
                        bb_perror_msg_and_die("pipe");
 
@@ -585,10 +584,15 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
        if (errorFlag)
                bb_error_msg("error exit delayed from previous errors");
 
-       if (gzipPid && waitpid(gzipPid, NULL, 0) == -1)
-               bb_error_msg("waitpid failed");
-
-       return !errorFlag;
+       if (gzipPid) {
+               int status;
+               if (waitpid(gzipPid, &status, 0) == -1)
+                       bb_perror_msg("waitpid");
+               else if (!WIFEXITED(status) || WEXITSTATUS(status))
+                       /* gzip was killed or has exited with nonzero! */
+                       errorFlag = TRUE;
+       }
+       return errorFlag;
 }
 #else
 int writeTarFile(const int tar_fd, const int verboseFlag,
@@ -650,6 +654,29 @@ static char get_header_tar_Z(archive_handle_t *archive_handle)
 #define get_header_tar_Z       0
 #endif
 
+#ifdef CHECK_FOR_CHILD_EXITCODE
+/* Looks like it isn't needed - tar detects malformed (truncated)
+ * archive if e.g. bunzip2 fails */
+static int child_error;
+
+static void handle_SIGCHLD(int status)
+{
+       /* Actually, 'status' is a signo. We reuse it for other needs */
+
+       /* Wait for any child without blocking */
+       if (waitpid(-1, &status, WNOHANG) < 0)
+               /* wait failed?! I'm confused... */
+               return;
+
+       if (WIFEXITED(status) && WEXITSTATUS(status)==0)
+               /* child exited with 0 */
+               return;
+       /* Cannot happen? 
+       if(!WIFSIGNALED(status) && !WIFEXITED(status)) return; */
+       child_error = 1;
+}
+#endif
+
 enum {
        OPTBIT_KEEP_OLD = 7,
        USE_FEATURE_TAR_CREATE(  OPTBIT_CREATE      ,)
@@ -862,6 +889,11 @@ int tar_main(int argc, char **argv)
        if (base_dir)
                xchdir(base_dir);
 
+#ifdef CHECK_FOR_CHILD_EXITCODE
+       /* We need to know whether child (gzip/bzip/etc) exits abnormally */
+       signal(SIGCHLD, handle_SIGCHLD);
+#endif
+
        /* create an archive */
        if (opt & OPT_CREATE) {
                int zipMode = 0;
@@ -869,11 +901,10 @@ int tar_main(int argc, char **argv)
                        zipMode = 1;
                if (ENABLE_FEATURE_TAR_BZIP2 && get_header_ptr == get_header_tar_bz2)
                        zipMode = 2;
-               writeTarFile(tar_handle->src_fd, verboseFlag, opt & OPT_DEREFERENCE,
+               /* NB: writeTarFile() closes tar_handle->src_fd */
+               return writeTarFile(tar_handle->src_fd, verboseFlag, opt & OPT_DEREFERENCE,
                                tar_handle->accept,
                                tar_handle->reject, zipMode);
-               /* NB: writeTarFile() closes tar_handle->src_fd */
-               return EXIT_SUCCESS;
        }
 
        while (get_header_ptr(tar_handle) == EXIT_SUCCESS)