diff options
Diffstat (limited to 'src/dd.c')
| -rw-r--r-- | src/dd.c | 69 |
1 files changed, 49 insertions, 20 deletions
@@ -627,22 +627,14 @@ Each FLAG symbol may be:\n\ "), stdout); { - char const *siginfo_name = (SIGINFO == SIGUSR1 ? "USR1" : "INFO"); printf (_("\ \n\ Sending a %s signal to a running 'dd' process makes it\n\ print I/O statistics to standard error and then resume copying.\n\ \n\ - $ dd if=/dev/zero of=/dev/null& pid=$!\n\ - $ kill -%s $pid; sleep 1; kill $pid\n\ - 18335302+0 records in\n\ - 18335302+0 records out\n\ - 9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s\n\ -\n\ Options are:\n\ \n\ -"), - siginfo_name, siginfo_name); +"), SIGINFO == SIGUSR1 ? "USR1" : "INFO"); } fputs (HELP_OPTION_DESCRIPTION, stdout); @@ -830,11 +822,7 @@ install_signal_handlers (void) struct sigaction act; sigemptyset (&caught_signals); if (catch_siginfo) - { - sigaction (SIGINFO, NULL, &act); - if (act.sa_handler != SIG_IGN) - sigaddset (&caught_signals, SIGINFO); - } + sigaddset (&caught_signals, SIGINFO); sigaction (SIGINT, NULL, &act); if (act.sa_handler != SIG_IGN) sigaddset (&caught_signals, SIGINT); @@ -843,6 +831,9 @@ install_signal_handlers (void) if (sigismember (&caught_signals, SIGINFO)) { act.sa_handler = siginfo_handler; + /* Note we don't use SA_RESTART here and instead + handle EINTR explicitly in iftruncate() etc. + to avoid blocking on noncommitted read()/write() calls. */ act.sa_flags = 0; sigaction (SIGINFO, &act, NULL); } @@ -856,7 +847,7 @@ install_signal_handlers (void) #else - if (catch_siginfo && signal (SIGINFO, SIG_IGN) != SIG_IGN) + if (catch_siginfo) { signal (SIGINFO, siginfo_handler); siginterrupt (SIGINFO, 1); @@ -1033,6 +1024,10 @@ iread (int fd, char *buf, size_t size) } while (nread < 0 && errno == EINTR); + /* Short read may be due to received signal. */ + if (0 < nread && nread < size) + process_signals (); + if (0 < nread && warn_partial_read) { static ssize_t prev_nread; @@ -1173,6 +1168,40 @@ write_output (void) oc = 0; } +/* Restart on EINTR from fd_reopen(). */ + +static int +ifd_reopen (int desired_fd, char const *file, int flag, mode_t mode) +{ + int ret; + + do + { + process_signals (); + ret = fd_reopen (desired_fd, file, flag, mode); + } + while (ret < 0 && errno == EINTR); + + return ret; +} + +/* Restart on EINTR from ftruncate(). */ + +static int +iftruncate (int fd, off_t length) +{ + int ret; + + do + { + process_signals (); + ret = ftruncate (fd, length); + } + while (ret < 0 && errno == EINTR); + + return ret; +} + /* Return true if STR is of the form "PATTERN" or "PATTERNDELIM...". */ static bool _GL_ATTRIBUTE_PURE @@ -2172,7 +2201,7 @@ dd_copy (void) off_t output_offset = lseek (STDOUT_FILENO, 0, SEEK_CUR); if (output_offset > stdout_stat.st_size) { - if (ftruncate (STDOUT_FILENO, output_offset) != 0) + if (iftruncate (STDOUT_FILENO, output_offset) != 0) { error (0, errno, _("failed to truncate to %" PRIdMAX " bytes" @@ -2248,7 +2277,7 @@ main (int argc, char **argv) } else { - if (fd_reopen (STDIN_FILENO, input_file, O_RDONLY | input_flags, 0) < 0) + if (ifd_reopen (STDIN_FILENO, input_file, O_RDONLY | input_flags, 0) < 0) error (EXIT_FAILURE, errno, _("failed to open %s"), quote (input_file)); } @@ -2275,8 +2304,8 @@ main (int argc, char **argv) need to read to satisfy a 'seek=' request. If we can't read the file, go ahead with write-only access; it might work. */ if ((! seek_records - || fd_reopen (STDOUT_FILENO, output_file, O_RDWR | opts, perms) < 0) - && (fd_reopen (STDOUT_FILENO, output_file, O_WRONLY | opts, perms) + || ifd_reopen (STDOUT_FILENO, output_file, O_RDWR | opts, perms) < 0) + && (ifd_reopen (STDOUT_FILENO, output_file, O_WRONLY | opts, perms) < 0)) error (EXIT_FAILURE, errno, _("failed to open %s"), quote (output_file)); @@ -2293,7 +2322,7 @@ main (int argc, char **argv) " (%lu-byte) blocks"), seek_records, obs); - if (ftruncate (STDOUT_FILENO, size) != 0) + if (iftruncate (STDOUT_FILENO, size) != 0) { /* Complain only when ftruncate fails on a regular file, a directory, or a shared memory object, as POSIX 1003.1-2004 |