X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/907e6a32a00ace7cf1e96f9c9132f83f4a208430..f8e1fa627219873be6d37244dc70fbfd157f1e9c:/io.c diff --git a/io.c b/io.c index 9b1cdbcb..d142a1a6 100644 --- a/io.c +++ b/io.c @@ -69,6 +69,7 @@ int ignore_timeout = 0; int batch_fd = -1; int msgdone_cnt = 0; int forward_flist_data = 0; +BOOL flist_receiving_enabled = False; /* Ignore an EOF error if non-zero. See whine_about_eof(). */ int kluge_around_eof = 0; @@ -83,7 +84,7 @@ static struct { xbuf in, out, msg; int in_fd; int out_fd; /* Both "out" and "msg" go to this fd. */ - BOOL in_multiplexed; + int in_multiplexed; unsigned out_empty_len; size_t raw_data_header_pos; /* in the out xbuf */ size_t raw_flushing_ends_before; /* in the out xbuf */ @@ -126,7 +127,8 @@ static char int_byte_extra[64] = { #define IOBUF_WAS_REDUCED(siz) ((siz) & 0xFF) #define IOBUF_RESTORE_SIZE(siz) (((siz) | 0xFF) + 1) -#define IN_MULTIPLEXED (iobuf.in_multiplexed) +#define IN_MULTIPLEXED (iobuf.in_multiplexed != 0) +#define IN_MULTIPLEXED_AND_READY (iobuf.in_multiplexed > 0) #define OUT_MULTIPLEXED (iobuf.out_empty_len != 0) #define PIO_NEED_INPUT (1<<0) /* The *_NEED_* flags are mutually exclusive. */ @@ -147,6 +149,7 @@ enum festatus { FES_SUCCESS, FES_REDO, FES_NO_SEND }; static flist_ndx_list redo_list, hlink_list; +static void read_a_msg(void); static void drain_multiplex_messages(void); static void sleep_for_bwlimit(int bytes_written); @@ -500,10 +503,11 @@ void restore_iobuf_size(xbuf *out) * The iobuf.out and iobuf.msg buffers are circular, so some writes into them * will need to be split when the data needs to wrap around to the start. In * order to help make this easier for some operations (such as the use of - * SIVAL() into the buffer) the buffers MUST have 4 bytes of overflow space at - * the end that is not not counted in the "size". The iobuf.in buffer is not - * (currently) circular. To facilitate the handling of MSG_DATA bytes as they - * are read-from/written-into the buffers, see the three raw_* iobuf vars. + * SIVAL() into the buffer) a buffer may be temporarily shortened, but the + * original size will be automatically restored. The iobuf.in buffer is also + * circular, so callers may need to split their reading of the data if it spans + * the end. See also the 3 raw_* iobuf vars that are used in the handling of + * MSG_DATA bytes as they are read-from/written-into the buffers. * * When writing, we flush data in the following priority order: * @@ -520,8 +524,6 @@ void restore_iobuf_size(xbuf *out) * * - Make this routine able to read the generator-to-receiver batch flow? * - * - Make the input buffer circular? - * * Unlike the old routines that this replaces, it is OK to read ahead as far as * we can because the read_a_msg() routine now reads its bytes out of the input * buffer. In the old days, only raw data was in the input buffer, and any @@ -543,35 +545,17 @@ static char *perform_io(size_t needed, int flags) switch (flags & PIO_NEED_FLAGS) { case PIO_NEED_INPUT: + /* We never resize the circular input buffer. */ + if (iobuf.in.size < needed) { + rprintf(FERROR, "need to read %ld bytes, iobuf.in.buf is only %ld bytes.\n", + (long)needed, (long)iobuf.in.size); + exit_cleanup(RERR_PROTOCOL); + } + if (DEBUG_GTE(IO, 3)) { rprintf(FINFO, "[%s] perform_io(%ld, %sinput)\n", who_am_i(), (long)needed, flags & PIO_CONSUME_INPUT ? "consume&" : ""); } - - /* Make sure the input buffer is big enough to hold "needed" bytes. - * Also make sure it will fit in the free space at the end, or - * else we need to shift some bytes. */ - if (needed && iobuf.in.size < needed) { - size_t new_size = ROUND_UP_1024(needed); - if (DEBUG_GTE(IO, 4)) { - rprintf(FINFO, "[%s] resizing input buffer from %ld to %ld bytes.\n", - who_am_i(), (long)iobuf.in.size, (long)new_size); - } - realloc_xbuf(&iobuf.in, new_size); - } - if (iobuf.in.size - iobuf.in.pos < needed - || (iobuf.in.len < needed && iobuf.in.len < 1024 - && iobuf.in.size - (iobuf.in.pos + iobuf.in.len) < 1024)) { - memmove(iobuf.in.buf, iobuf.in.buf + iobuf.in.pos, iobuf.in.len); - if (DEBUG_GTE(IO, 4)) { - rprintf(FINFO, - "[%s] moved %ld bytes from %ld to 0 in the input buffer (size=%ld, needed=%ld).\n", - who_am_i(), (long)iobuf.in.len, (long)iobuf.in.pos, (long)iobuf.in.size, (long)needed); - } - if (iobuf.raw_input_ends_before) - iobuf.raw_input_ends_before -= iobuf.in.pos; - iobuf.in.pos = 0; - } break; case PIO_NEED_OUTROOM: @@ -637,7 +621,7 @@ static char *perform_io(size_t needed, int flags) FD_ZERO(&r_fds); FD_ZERO(&e_fds); - if (iobuf.in_fd >= 0 && iobuf.in.size - (iobuf.in.pos + iobuf.in.len)) { + if (iobuf.in_fd >= 0 && iobuf.in.size - iobuf.in.len) { if (!read_batch || batch_fd >= 0) { FD_SET(iobuf.in_fd, &r_fds); FD_SET(iobuf.in_fd, &e_fds); @@ -754,9 +738,13 @@ static char *perform_io(size_t needed, int flags) } if (iobuf.in_fd >= 0 && FD_ISSET(iobuf.in_fd, &r_fds)) { - size_t pos = iobuf.in.pos + iobuf.in.len; - size_t len = iobuf.in.size - pos; + size_t len, pos = iobuf.in.pos + iobuf.in.len; int n; + if (pos >= iobuf.in.size) { + pos -= iobuf.in.size; + len = iobuf.in.size - iobuf.in.len; + } else + len = iobuf.in.size - pos; if ((n = read(iobuf.in_fd, iobuf.in.buf + pos, len)) <= 0) { if (n == 0) { /* Signal that input has become invalid. */ @@ -788,7 +776,7 @@ static char *perform_io(size_t needed, int flags) iobuf.in.len += n; } - if (iobuf.out_fd >= 0 && FD_ISSET(iobuf.out_fd, &w_fds)) { + if (out && FD_ISSET(iobuf.out_fd, &w_fds)) { size_t len = iobuf.raw_flushing_ends_before ? iobuf.raw_flushing_ends_before - out->pos : out->len; int n; @@ -837,6 +825,15 @@ static char *perform_io(size_t needed, int flags) } } + /* We need to help prevent deadlock by doing what reading + * we can whenever we are here trying to write. */ + if (IN_MULTIPLEXED_AND_READY && !(flags & PIO_NEED_INPUT)) { + while (!iobuf.raw_input_ends_before && iobuf.in.len > 512) + read_a_msg(); + if (flist_receiving_enabled && iobuf.in.len > 512) + wait_for_receiver(); /* generator only */ + } + if (ff_forward_fd >= 0 && FD_ISSET(ff_forward_fd, &r_fds)) { /* This can potentially flush all output and enable * multiplexed output, so keep this last in the loop @@ -852,11 +849,40 @@ static char *perform_io(size_t needed, int flags) if (flags & PIO_CONSUME_INPUT) { iobuf.in.len -= needed; iobuf.in.pos += needed; + if (iobuf.in.pos == iobuf.raw_input_ends_before) + iobuf.raw_input_ends_before = 0; + if (iobuf.in.pos >= iobuf.in.size) { + iobuf.in.pos -= iobuf.in.size; + if (iobuf.raw_input_ends_before) + iobuf.raw_input_ends_before -= iobuf.in.size; + } } return data; } +static void raw_read_buf(char *buf, size_t len) +{ + size_t pos = iobuf.in.pos; + char *data = perform_io(len, PIO_INPUT_AND_CONSUME); + if (iobuf.in.pos <= pos && len) { + size_t siz = len - iobuf.in.pos; + memcpy(buf, data, siz); + memcpy(buf + siz, iobuf.in.buf, iobuf.in.pos); + } else + memcpy(buf, data, len); +} + +static int32 raw_read_int(void) +{ + char *data, buf[4]; + if (iobuf.in.size - iobuf.in.pos >= 4) + data = perform_io(4, PIO_INPUT_AND_CONSUME); + else + raw_read_buf(data = buf, 4); + return IVAL(data, 0); +} + void noop_io_until_death(void) { char buf[1024]; @@ -1322,17 +1348,22 @@ void stop_flist_forward(void) /* Read a message from a multiplexed source. */ static void read_a_msg(void) { - char *data, line[BIGPATHBUFLEN]; + char data[BIGPATHBUFLEN]; int tag, val; size_t msg_bytes; - data = perform_io(4, PIO_INPUT_AND_CONSUME); - tag = IVAL(data, 0); + /* This ensures that perform_io() does not try to do any message reading + * until we've read all of the data for this message. We should also + * try to avoid calling things that will cause data to be written via + * perform_io() prior to this being reset to 1. */ + iobuf.in_multiplexed = -1; + + tag = raw_read_int(); msg_bytes = tag & 0xFFFFFF; tag = (tag >> 24) - MPLEX_BASE; - if (DEBUG_GTE(IO, 1) && (msgs2stderr || tag != MSG_INFO)) + if (DEBUG_GTE(IO, 1) && msgs2stderr) rprintf(FINFO, "[%s] got msg=%d, len=%ld\n", who_am_i(), (int)tag, (long)msg_bytes); switch (tag) { @@ -1344,24 +1375,26 @@ static void read_a_msg(void) * which case the gradual reading of the input stream will * cause this value to decrease and eventually become real. */ iobuf.raw_input_ends_before = iobuf.in.pos + msg_bytes; + iobuf.in_multiplexed = 1; break; case MSG_STATS: if (msg_bytes != sizeof stats.total_read || !am_generator) goto invalid_msg; - data = perform_io(sizeof stats.total_read, PIO_INPUT_AND_CONSUME); - memcpy((char*)&stats.total_read, data, sizeof stats.total_read); + raw_read_buf((char*)&stats.total_read, sizeof stats.total_read); + iobuf.in_multiplexed = 1; break; case MSG_REDO: if (msg_bytes != 4 || !am_generator) goto invalid_msg; - data = perform_io(4, PIO_INPUT_AND_CONSUME); - got_flist_entry_status(FES_REDO, IVAL(data, 0)); + val = raw_read_int(); + iobuf.in_multiplexed = 1; + got_flist_entry_status(FES_REDO, val); break; case MSG_IO_ERROR: if (msg_bytes != 4 || am_sender) goto invalid_msg; - data = perform_io(4, PIO_INPUT_AND_CONSUME); - val = IVAL(data, 0); + val = raw_read_int(); + iobuf.in_multiplexed = 1; io_error |= val; if (!am_generator) send_msg_int(MSG_IO_ERROR, val); @@ -1369,8 +1402,8 @@ static void read_a_msg(void) case MSG_IO_TIMEOUT: if (msg_bytes != 4 || am_server || am_generator) goto invalid_msg; - data = perform_io(4, PIO_INPUT_AND_CONSUME); - val = IVAL(data, 0); + val = raw_read_int(); + iobuf.in_multiplexed = 1; if (!io_timeout || io_timeout > val) { if (INFO_GTE(MISC, 2)) rprintf(FINFO, "Setting --timeout=%d to match server\n", val); @@ -1380,13 +1413,15 @@ static void read_a_msg(void) case MSG_NOOP: if (am_sender) maybe_send_keepalive(); + iobuf.in_multiplexed = 1; break; case MSG_DELETED: - if (msg_bytes >= sizeof line) + if (msg_bytes >= sizeof data) goto overflow; if (am_generator) { - memcpy(line, perform_io(msg_bytes, PIO_INPUT_AND_CONSUME), msg_bytes); - send_msg(MSG_DELETED, line, msg_bytes, 1); + raw_read_buf(data, msg_bytes); + iobuf.in_multiplexed = 1; + send_msg(MSG_DELETED, data, msg_bytes, 1); break; } #ifdef ICONV_OPTION @@ -1396,12 +1431,12 @@ static void read_a_msg(void) int add_null = 0; int flags = ICB_INCLUDE_BAD | ICB_INIT; - INIT_CONST_XBUF(outbuf, line); + INIT_CONST_XBUF(outbuf, data); INIT_XBUF(inbuf, ibuf, 0, (size_t)-1); while (msg_bytes) { size_t len = msg_bytes > sizeof ibuf - inbuf.len ? sizeof ibuf - inbuf.len : msg_bytes; - memcpy(ibuf + inbuf.len, perform_io(len, PIO_INPUT_AND_CONSUME), len); + raw_read_buf(ibuf + inbuf.len, len); inbuf.pos = 0; inbuf.len += len; if (!(msg_bytes -= len) && !ibuf[inbuf.len-1]) @@ -1423,13 +1458,14 @@ static void read_a_msg(void) msg_bytes = outbuf.len; } else #endif - memcpy(line, perform_io(msg_bytes, PIO_INPUT_AND_CONSUME), msg_bytes); + raw_read_buf(data, msg_bytes); + iobuf.in_multiplexed = 1; /* A directory name was sent with the trailing null */ - if (msg_bytes > 0 && !line[msg_bytes-1]) - log_delete(line, S_IFDIR); + if (msg_bytes > 0 && !data[msg_bytes-1]) + log_delete(data, S_IFDIR); else { - line[msg_bytes] = '\0'; - log_delete(line, S_IFREG); + data[msg_bytes] = '\0'; + log_delete(data, S_IFREG); } break; case MSG_SUCCESS: @@ -1440,8 +1476,8 @@ static void read_a_msg(void) inc_recurse ? "/inc" : ""); exit_cleanup(RERR_STREAMIO); } - data = perform_io(4, PIO_INPUT_AND_CONSUME); - val = IVAL(data, 0); + val = raw_read_int(); + iobuf.in_multiplexed = 1; if (am_generator) got_flist_entry_status(FES_SUCCESS, val); else @@ -1450,8 +1486,8 @@ static void read_a_msg(void) case MSG_NO_SEND: if (msg_bytes != 4) goto invalid_msg; - data = perform_io(4, PIO_INPUT_AND_CONSUME); - val = IVAL(data, 0); + val = raw_read_int(); + iobuf.in_multiplexed = 1; if (am_generator) got_flist_entry_status(FES_NO_SEND, val); else @@ -1470,7 +1506,7 @@ static void read_a_msg(void) case MSG_ERROR: case MSG_ERROR_XFER: case MSG_WARNING: - if (msg_bytes >= sizeof line) { + if (msg_bytes >= sizeof data) { overflow: rprintf(FERROR, "multiplexing overflow %d:%lu [%s%s]\n", @@ -1478,34 +1514,55 @@ static void read_a_msg(void) inc_recurse ? "/inc" : ""); exit_cleanup(RERR_STREAMIO); } - memcpy(line, perform_io(msg_bytes, PIO_INPUT_AND_CONSUME), msg_bytes); - rwrite((enum logcode)tag, line, msg_bytes, !am_generator); + raw_read_buf(data, msg_bytes); + iobuf.in_multiplexed = 1; + rwrite((enum logcode)tag, data, msg_bytes, !am_generator); if (first_message) { - if (list_only && !am_sender && tag == 1 && msg_bytes < sizeof line) { - line[msg_bytes] = '\0'; - check_for_d_option_error(line); + if (list_only && !am_sender && tag == 1 && msg_bytes < sizeof data) { + data[msg_bytes] = '\0'; + check_for_d_option_error(data); } first_message = 0; } break; case MSG_ERROR_EXIT: + if (msg_bytes == 4) + val = raw_read_int(); + else if (msg_bytes == 0) + val = 0; + else + goto invalid_msg; + iobuf.in_multiplexed = 1; + if (DEBUG_GTE(EXIT, 3)) + rprintf(FINFO, "[%s] got MSG_ERROR_EXIT with %ld bytes\n", who_am_i(), (long)msg_bytes); if (msg_bytes == 0) { if (!am_sender && !am_generator) { + if (DEBUG_GTE(EXIT, 3)) { + rprintf(FINFO, "[%s] sending MSG_ERROR_EXIT (len 0)\n", + who_am_i()); + } send_msg(MSG_ERROR_EXIT, "", 0, 0); io_flush(FULL_FLUSH); } val = 0; - } else if (msg_bytes == 4) { - data = perform_io(4, PIO_INPUT_AND_CONSUME); - val = IVAL(data, 0); + } else { + val = raw_read_int(); if (protocol_version >= 31) { - if (am_generator) + if (am_generator) { + if (DEBUG_GTE(EXIT, 3)) { + rprintf(FINFO, "[%s] sending MSG_ERROR_EXIT with exit_code %d\n", + who_am_i(), val); + } send_msg_int(MSG_ERROR_EXIT, val); - else + } else { + if (DEBUG_GTE(EXIT, 3)) { + rprintf(FINFO, "[%s] sending MSG_ERROR_EXIT (len 0)\n", + who_am_i()); + } send_msg(MSG_ERROR_EXIT, "", 0, 0); + } } - } else - goto invalid_msg; + } /* Send a negative linenum so that we don't end up * with a duplicate exit message. */ _exit_cleanup(val, __FILE__, 0 - __LINE__); @@ -1514,11 +1571,13 @@ static void read_a_msg(void) tag, who_am_i(), inc_recurse ? "/inc" : ""); exit_cleanup(RERR_STREAMIO); } + + assert(iobuf.in_multiplexed > 0); } static void drain_multiplex_messages(void) { - while (IN_MULTIPLEXED && iobuf.in.len) { + while (IN_MULTIPLEXED_AND_READY && iobuf.in.len) { if (iobuf.raw_input_ends_before) { size_t raw_len = iobuf.raw_input_ends_before - iobuf.in.pos; iobuf.raw_input_ends_before = 0; @@ -1526,8 +1585,9 @@ static void drain_multiplex_messages(void) iobuf.in.len = 0; break; } - iobuf.in.pos += raw_len; iobuf.in.len -= raw_len; + if ((iobuf.in.pos += raw_len) >= iobuf.in.size) + iobuf.in.pos -= iobuf.in.size; } read_a_msg(); } @@ -1555,6 +1615,7 @@ void wait_for_receiver(void) } } else { struct file_list *flist; + flist_receiving_enabled = False; if (DEBUG_GTE(FLIST, 2)) { rprintf(FINFO, "[%s] receiving flist for dir %d\n", who_am_i(), ndx); @@ -1565,6 +1626,7 @@ void wait_for_receiver(void) if (preserve_hard_links) match_hard_links(flist); #endif + flist_receiving_enabled = True; } } } @@ -1691,7 +1753,7 @@ void read_buf(int f, char *buf, size_t len) } if (!IN_MULTIPLEXED) { - memcpy(buf, perform_io(len, PIO_INPUT_AND_CONSUME), len); + raw_read_buf(buf, len); total_data_read += len; if (forward_flist_data) write_buf(iobuf.out_fd, buf, len); @@ -1702,20 +1764,15 @@ void read_buf(int f, char *buf, size_t len) } while (1) { - char *data; size_t siz; while (!iobuf.raw_input_ends_before) read_a_msg(); siz = MIN(len, iobuf.raw_input_ends_before - iobuf.in.pos); - data = perform_io(siz, PIO_INPUT_AND_CONSUME); - if (iobuf.in.pos == iobuf.raw_input_ends_before) - iobuf.raw_input_ends_before = 0; - - /* The bytes at the "data" pointer will survive long - * enough to make a copy, but not past future I/O. */ - memcpy(buf, data, siz); + if (siz >= iobuf.in.size) + siz = iobuf.in.size; + raw_read_buf(buf, siz); total_data_read += siz; if (forward_flist_data) @@ -2177,7 +2234,7 @@ void io_start_multiplex_in(int fd) if (msgs2stderr && DEBUG_GTE(IO, 2)) rprintf(FINFO, "[%s] io_start_multiplex_in(%d)\n", who_am_i(), fd); - iobuf.in_multiplexed = True; /* See also IN_MULTIPLEXED */ + iobuf.in_multiplexed = 1; /* See also IN_MULTIPLEXED */ io_start_buffering_in(fd); } @@ -2188,7 +2245,7 @@ int io_end_multiplex_in(int mode) if (msgs2stderr && DEBUG_GTE(IO, 2)) rprintf(FINFO, "[%s] io_end_multiplex_in(mode=%d)\n", who_am_i(), mode); - iobuf.in_multiplexed = False; + iobuf.in_multiplexed = 0; if (mode == MPLX_SWITCHING) iobuf.raw_input_ends_before = 0; else