From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 26 May 2011 17:27:55 +0000 (-0700)
Subject: Merge branch 'js/maint-send-pack-stateless-rpc-deadlock-fix' into maint-1.7.4
X-Git-Tag: v1.7.5.3~1^2~1
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=34df9fe36a3627e1c2a9ae244820fb61e3891b90;p=git.git

Merge branch 'js/maint-send-pack-stateless-rpc-deadlock-fix' into maint-1.7.4

* js/maint-send-pack-stateless-rpc-deadlock-fix:
  sideband_demux(): fix decl-after-stmt
  send-pack: unbreak push over stateless rpc
  send-pack: avoid deadlock when pack-object dies early
---

34df9fe36a3627e1c2a9ae244820fb61e3891b90
diff --cc builtin/send-pack.c
index 2cd1c40b7,000000000..eb38ab4e0
mode 100644,000000..100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@@ -1,534 -1,0 +1,539 @@@
 +#include "cache.h"
 +#include "commit.h"
 +#include "refs.h"
 +#include "pkt-line.h"
 +#include "sideband.h"
 +#include "run-command.h"
 +#include "remote.h"
 +#include "send-pack.h"
 +#include "quote.h"
 +#include "transport.h"
 +
 +static const char send_pack_usage[] =
 +"git send-pack [--all | --mirror] [--dry-run] [--force] [--receive-pack=<git-receive-pack>] [--verbose] [--thin] [<host>:]<directory> [<ref>...]\n"
 +"  --all and explicit <ref> specification are mutually exclusive.";
 +
 +static struct send_pack_args args;
 +
 +static int feed_object(const unsigned char *sha1, int fd, int negative)
 +{
 +	char buf[42];
 +
 +	if (negative && !has_sha1_file(sha1))
 +		return 1;
 +
 +	memcpy(buf + negative, sha1_to_hex(sha1), 40);
 +	if (negative)
 +		buf[0] = '^';
 +	buf[40 + negative] = '\n';
 +	return write_or_whine(fd, buf, 41 + negative, "send-pack: send refs");
 +}
 +
 +/*
 + * Make a pack stream and spit it out into file descriptor fd
 + */
 +static int pack_objects(int fd, struct ref *refs, struct extra_have_objects *extra, struct send_pack_args *args)
 +{
 +	/*
 +	 * The child becomes pack-objects --revs; we feed
 +	 * the revision parameters to it via its stdin and
 +	 * let its stdout go back to the other end.
 +	 */
 +	const char *argv[] = {
 +		"pack-objects",
 +		"--all-progress-implied",
 +		"--revs",
 +		"--stdout",
 +		NULL,
 +		NULL,
 +		NULL,
 +		NULL,
 +		NULL,
 +	};
 +	struct child_process po;
 +	int i;
 +
 +	i = 4;
 +	if (args->use_thin_pack)
 +		argv[i++] = "--thin";
 +	if (args->use_ofs_delta)
 +		argv[i++] = "--delta-base-offset";
 +	if (args->quiet)
 +		argv[i++] = "-q";
 +	if (args->progress)
 +		argv[i++] = "--progress";
 +	memset(&po, 0, sizeof(po));
 +	po.argv = argv;
 +	po.in = -1;
 +	po.out = args->stateless_rpc ? -1 : fd;
 +	po.git_cmd = 1;
 +	if (start_command(&po))
 +		die_errno("git pack-objects failed");
 +
 +	/*
 +	 * We feed the pack-objects we just spawned with revision
 +	 * parameters by writing to the pipe.
 +	 */
 +	for (i = 0; i < extra->nr; i++)
 +		if (!feed_object(extra->array[i], po.in, 1))
 +			break;
 +
 +	while (refs) {
 +		if (!is_null_sha1(refs->old_sha1) &&
 +		    !feed_object(refs->old_sha1, po.in, 1))
 +			break;
 +		if (!is_null_sha1(refs->new_sha1) &&
 +		    !feed_object(refs->new_sha1, po.in, 0))
 +			break;
 +		refs = refs->next;
 +	}
 +
 +	close(po.in);
 +
 +	if (args->stateless_rpc) {
 +		char *buf = xmalloc(LARGE_PACKET_MAX);
 +		while (1) {
 +			ssize_t n = xread(po.out, buf, LARGE_PACKET_MAX);
 +			if (n <= 0)
 +				break;
 +			send_sideband(fd, -1, buf, n, LARGE_PACKET_MAX);
 +		}
 +		free(buf);
 +		close(po.out);
 +		po.out = -1;
 +	}
 +
 +	if (finish_command(&po))
 +		return -1;
 +	return 0;
 +}
 +
 +static int receive_status(int in, struct ref *refs)
 +{
 +	struct ref *hint;
 +	char line[1000];
 +	int ret = 0;
 +	int len = packet_read_line(in, line, sizeof(line));
 +	if (len < 10 || memcmp(line, "unpack ", 7))
 +		return error("did not receive remote status");
 +	if (memcmp(line, "unpack ok\n", 10)) {
 +		char *p = line + strlen(line) - 1;
 +		if (*p == '\n')
 +			*p = '\0';
 +		error("unpack failed: %s", line + 7);
 +		ret = -1;
 +	}
 +	hint = NULL;
 +	while (1) {
 +		char *refname;
 +		char *msg;
 +		len = packet_read_line(in, line, sizeof(line));
 +		if (!len)
 +			break;
 +		if (len < 3 ||
 +		    (memcmp(line, "ok ", 3) && memcmp(line, "ng ", 3))) {
 +			fprintf(stderr, "protocol error: %s\n", line);
 +			ret = -1;
 +			break;
 +		}
 +
 +		line[strlen(line)-1] = '\0';
 +		refname = line + 3;
 +		msg = strchr(refname, ' ');
 +		if (msg)
 +			*msg++ = '\0';
 +
 +		/* first try searching at our hint, falling back to all refs */
 +		if (hint)
 +			hint = find_ref_by_name(hint, refname);
 +		if (!hint)
 +			hint = find_ref_by_name(refs, refname);
 +		if (!hint) {
 +			warning("remote reported status on unknown ref: %s",
 +					refname);
 +			continue;
 +		}
 +		if (hint->status != REF_STATUS_EXPECTING_REPORT) {
 +			warning("remote reported status on unexpected ref: %s",
 +					refname);
 +			continue;
 +		}
 +
 +		if (line[0] == 'o' && line[1] == 'k')
 +			hint->status = REF_STATUS_OK;
 +		else {
 +			hint->status = REF_STATUS_REMOTE_REJECT;
 +			ret = -1;
 +		}
 +		if (msg)
 +			hint->remote_status = xstrdup(msg);
 +		/* start our next search from the next ref */
 +		hint = hint->next;
 +	}
 +	return ret;
 +}
 +
 +static void print_helper_status(struct ref *ref)
 +{
 +	struct strbuf buf = STRBUF_INIT;
 +
 +	for (; ref; ref = ref->next) {
 +		const char *msg = NULL;
 +		const char *res;
 +
 +		switch(ref->status) {
 +		case REF_STATUS_NONE:
 +			res = "error";
 +			msg = "no match";
 +			break;
 +
 +		case REF_STATUS_OK:
 +			res = "ok";
 +			break;
 +
 +		case REF_STATUS_UPTODATE:
 +			res = "ok";
 +			msg = "up to date";
 +			break;
 +
 +		case REF_STATUS_REJECT_NONFASTFORWARD:
 +			res = "error";
 +			msg = "non-fast forward";
 +			break;
 +
 +		case REF_STATUS_REJECT_NODELETE:
 +		case REF_STATUS_REMOTE_REJECT:
 +			res = "error";
 +			break;
 +
 +		case REF_STATUS_EXPECTING_REPORT:
 +		default:
 +			continue;
 +		}
 +
 +		strbuf_reset(&buf);
 +		strbuf_addf(&buf, "%s %s", res, ref->name);
 +		if (ref->remote_status)
 +			msg = ref->remote_status;
 +		if (msg) {
 +			strbuf_addch(&buf, ' ');
 +			quote_two_c_style(&buf, "", msg, 0);
 +		}
 +		strbuf_addch(&buf, '\n');
 +
 +		safe_write(1, buf.buf, buf.len);
 +	}
 +	strbuf_release(&buf);
 +}
 +
 +static int sideband_demux(int in, int out, void *data)
 +{
- 	int *fd = data;
- 	int ret = recv_sideband("send-pack", fd[0], out);
++	int *fd = data, ret;
++#ifdef NO_PTHREADS
++	close(fd[1]);
++#endif
++	ret = recv_sideband("send-pack", fd[0], out);
 +	close(out);
 +	return ret;
 +}
 +
 +int send_pack(struct send_pack_args *args,
 +	      int fd[], struct child_process *conn,
 +	      struct ref *remote_refs,
 +	      struct extra_have_objects *extra_have)
 +{
 +	int in = fd[0];
 +	int out = fd[1];
 +	struct strbuf req_buf = STRBUF_INIT;
 +	struct ref *ref;
 +	int new_refs;
 +	int allow_deleting_refs = 0;
 +	int status_report = 0;
 +	int use_sideband = 0;
 +	unsigned cmds_sent = 0;
 +	int ret;
 +	struct async demux;
 +
 +	/* Does the other end support the reporting? */
 +	if (server_supports("report-status"))
 +		status_report = 1;
 +	if (server_supports("delete-refs"))
 +		allow_deleting_refs = 1;
 +	if (server_supports("ofs-delta"))
 +		args->use_ofs_delta = 1;
 +	if (server_supports("side-band-64k"))
 +		use_sideband = 1;
 +
 +	if (!remote_refs) {
 +		fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 +			"Perhaps you should specify a branch such as 'master'.\n");
 +		return 0;
 +	}
 +
 +	/*
 +	 * Finally, tell the other end!
 +	 */
 +	new_refs = 0;
 +	for (ref = remote_refs; ref; ref = ref->next) {
 +		if (!ref->peer_ref && !args->send_mirror)
 +			continue;
 +
 +		/* Check for statuses set by set_ref_status_for_push() */
 +		switch (ref->status) {
 +		case REF_STATUS_REJECT_NONFASTFORWARD:
 +		case REF_STATUS_UPTODATE:
 +			continue;
 +		default:
 +			; /* do nothing */
 +		}
 +
 +		if (ref->deletion && !allow_deleting_refs) {
 +			ref->status = REF_STATUS_REJECT_NODELETE;
 +			continue;
 +		}
 +
 +		if (!ref->deletion)
 +			new_refs++;
 +
 +		if (args->dry_run) {
 +			ref->status = REF_STATUS_OK;
 +		} else {
 +			char *old_hex = sha1_to_hex(ref->old_sha1);
 +			char *new_hex = sha1_to_hex(ref->new_sha1);
 +
 +			if (!cmds_sent && (status_report || use_sideband)) {
 +				packet_buf_write(&req_buf, "%s %s %s%c%s%s",
 +					old_hex, new_hex, ref->name, 0,
 +					status_report ? " report-status" : "",
 +					use_sideband ? " side-band-64k" : "");
 +			}
 +			else
 +				packet_buf_write(&req_buf, "%s %s %s",
 +					old_hex, new_hex, ref->name);
 +			ref->status = status_report ?
 +				REF_STATUS_EXPECTING_REPORT :
 +				REF_STATUS_OK;
 +			cmds_sent++;
 +		}
 +	}
 +
 +	if (args->stateless_rpc) {
 +		if (!args->dry_run && cmds_sent) {
 +			packet_buf_flush(&req_buf);
 +			send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
 +		}
 +	} else {
 +		safe_write(out, req_buf.buf, req_buf.len);
 +		packet_flush(out);
 +	}
 +	strbuf_release(&req_buf);
 +
 +	if (use_sideband && cmds_sent) {
 +		memset(&demux, 0, sizeof(demux));
 +		demux.proc = sideband_demux;
 +		demux.data = fd;
 +		demux.out = -1;
 +		if (start_async(&demux))
 +			die("receive-pack: unable to fork off sideband demultiplexer");
 +		in = demux.out;
 +	}
 +
 +	if (new_refs && cmds_sent) {
 +		if (pack_objects(out, remote_refs, extra_have, args) < 0) {
 +			for (ref = remote_refs; ref; ref = ref->next)
 +				ref->status = REF_STATUS_NONE;
++			if (args->stateless_rpc)
++				close(out);
 +			if (use_sideband)
 +				finish_async(&demux);
 +			return -1;
 +		}
 +	}
 +	if (args->stateless_rpc && cmds_sent)
 +		packet_flush(out);
 +
 +	if (status_report && cmds_sent)
 +		ret = receive_status(in, remote_refs);
 +	else
 +		ret = 0;
 +	if (args->stateless_rpc)
 +		packet_flush(out);
 +
 +	if (use_sideband && cmds_sent) {
 +		if (finish_async(&demux)) {
 +			error("error in sideband demultiplexer");
 +			ret = -1;
 +		}
 +		close(demux.out);
 +	}
 +
 +	if (ret < 0)
 +		return ret;
 +
 +	if (args->porcelain)
 +		return 0;
 +
 +	for (ref = remote_refs; ref; ref = ref->next) {
 +		switch (ref->status) {
 +		case REF_STATUS_NONE:
 +		case REF_STATUS_UPTODATE:
 +		case REF_STATUS_OK:
 +			break;
 +		default:
 +			return -1;
 +		}
 +	}
 +	return 0;
 +}
 +
 +int cmd_send_pack(int argc, const char **argv, const char *prefix)
 +{
 +	int i, nr_refspecs = 0;
 +	const char **refspecs = NULL;
 +	const char *remote_name = NULL;
 +	struct remote *remote = NULL;
 +	const char *dest = NULL;
 +	int fd[2];
 +	struct child_process *conn;
 +	struct extra_have_objects extra_have;
 +	struct ref *remote_refs, *local_refs;
 +	int ret;
 +	int helper_status = 0;
 +	int send_all = 0;
 +	const char *receivepack = "git-receive-pack";
 +	int flags;
 +	int nonfastforward = 0;
 +
 +	argv++;
 +	for (i = 1; i < argc; i++, argv++) {
 +		const char *arg = *argv;
 +
 +		if (*arg == '-') {
 +			if (!prefixcmp(arg, "--receive-pack=")) {
 +				receivepack = arg + 15;
 +				continue;
 +			}
 +			if (!prefixcmp(arg, "--exec=")) {
 +				receivepack = arg + 7;
 +				continue;
 +			}
 +			if (!prefixcmp(arg, "--remote=")) {
 +				remote_name = arg + 9;
 +				continue;
 +			}
 +			if (!strcmp(arg, "--all")) {
 +				send_all = 1;
 +				continue;
 +			}
 +			if (!strcmp(arg, "--dry-run")) {
 +				args.dry_run = 1;
 +				continue;
 +			}
 +			if (!strcmp(arg, "--mirror")) {
 +				args.send_mirror = 1;
 +				continue;
 +			}
 +			if (!strcmp(arg, "--force")) {
 +				args.force_update = 1;
 +				continue;
 +			}
 +			if (!strcmp(arg, "--verbose")) {
 +				args.verbose = 1;
 +				continue;
 +			}
 +			if (!strcmp(arg, "--thin")) {
 +				args.use_thin_pack = 1;
 +				continue;
 +			}
 +			if (!strcmp(arg, "--stateless-rpc")) {
 +				args.stateless_rpc = 1;
 +				continue;
 +			}
 +			if (!strcmp(arg, "--helper-status")) {
 +				helper_status = 1;
 +				continue;
 +			}
 +			usage(send_pack_usage);
 +		}
 +		if (!dest) {
 +			dest = arg;
 +			continue;
 +		}
 +		refspecs = (const char **) argv;
 +		nr_refspecs = argc - i;
 +		break;
 +	}
 +	if (!dest)
 +		usage(send_pack_usage);
 +	/*
 +	 * --all and --mirror are incompatible; neither makes sense
 +	 * with any refspecs.
 +	 */
 +	if ((refspecs && (send_all || args.send_mirror)) ||
 +	    (send_all && args.send_mirror))
 +		usage(send_pack_usage);
 +
 +	if (remote_name) {
 +		remote = remote_get(remote_name);
 +		if (!remote_has_url(remote, dest)) {
 +			die("Destination %s is not a uri for %s",
 +			    dest, remote_name);
 +		}
 +	}
 +
 +	if (args.stateless_rpc) {
 +		conn = NULL;
 +		fd[0] = 0;
 +		fd[1] = 1;
 +	} else {
 +		conn = git_connect(fd, dest, receivepack,
 +			args.verbose ? CONNECT_VERBOSE : 0);
 +	}
 +
 +	memset(&extra_have, 0, sizeof(extra_have));
 +
 +	get_remote_heads(fd[0], &remote_refs, 0, NULL, REF_NORMAL,
 +			 &extra_have);
 +
 +	transport_verify_remote_names(nr_refspecs, refspecs);
 +
 +	local_refs = get_local_heads();
 +
 +	flags = MATCH_REFS_NONE;
 +
 +	if (send_all)
 +		flags |= MATCH_REFS_ALL;
 +	if (args.send_mirror)
 +		flags |= MATCH_REFS_MIRROR;
 +
 +	/* match them up */
 +	if (match_refs(local_refs, &remote_refs, nr_refspecs, refspecs, flags))
 +		return -1;
 +
 +	set_ref_status_for_push(remote_refs, args.send_mirror,
 +		args.force_update);
 +
 +	ret = send_pack(&args, fd, conn, remote_refs, &extra_have);
 +
 +	if (helper_status)
 +		print_helper_status(remote_refs);
 +
 +	close(fd[1]);
 +	close(fd[0]);
 +
 +	ret |= finish_connect(conn);
 +
 +	if (!helper_status)
 +		transport_print_push_status(dest, remote_refs, args.verbose, 0, &nonfastforward);
 +
 +	if (!args.dry_run && remote) {
 +		struct ref *ref;
 +		for (ref = remote_refs; ref; ref = ref->next)
 +			transport_update_tracking_ref(remote, ref, args.verbose);
 +	}
 +
 +	if (!ret && !transport_refs_pushed(remote_refs))
 +		fprintf(stderr, "Everything up-to-date\n");
 +
 +	return ret;
 +}