From 60c6f7ec4186c15043a4c4b3ecd2297b9b11531c Mon Sep 17 00:00:00 2001 From: Thomas Braun Date: Thu, 8 May 2014 21:43:24 +0200 Subject: [PATCH] transport: optionally disable side-band-64k Since commit 0c499ea60fda (send-pack: demultiplex a sideband stream with status data, 2010-02-05) the send-pack builtin uses the side-band-64k capability if advertised by the server. Unfortunately this breaks pushing over the dump git protocol if used over a network connection. The detailed reasons for this breakage are (by courtesy of Jeff Preshing, quoted from https://groups.google.com/d/msg/msysgit/at8D7J-h7mw/eaLujILGUWoJ): MinGW wraps Windows sockets in CRT file descriptors in order to mimic the functionality of POSIX sockets. This causes msvcrt.dll to treat sockets as Installable File System (IFS) handles, calling ReadFile, WriteFile, DuplicateHandle and CloseHandle on them. This approach works well in simple cases on recent versions of Windows, but does not support all usage patterns. In particular, using this approach, any attempt to read & write concurrently on the same socket (from one or more processes) will deadlock in a scenario where the read waits for a response from the server which is only invoked after the write. This is what send_pack currently attempts to do in the use_sideband codepath. The new config option `sendpack.sideband` allows to override the side-band-64k capability of the server, and thus makes the dumb git protocol work. Other transportation methods like ssh and http/https still benefit from the sideband channel, therefore the default value of `sendpack.sideband` is still true. Signed-off-by: Thomas Braun Signed-off-by: Oliver Schneider Signed-off-by: Johannes Schindelin --- Documentation/config.txt | 2 ++ Documentation/config/sendpack.txt | 5 +++++ send-pack.c | 6 +++--- 3 files changed, 10 insertions(+), 3 deletions(-) create mode 100644 Documentation/config/sendpack.txt diff --git a/Documentation/config.txt b/Documentation/config.txt index 8c0b3ed8075214..3ad4956fe48944 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -518,6 +518,8 @@ include::config/safe.txt[] include::config/sendemail.txt[] +include::config/sendpack.txt[] + include::config/sequencer.txt[] include::config/showbranch.txt[] diff --git a/Documentation/config/sendpack.txt b/Documentation/config/sendpack.txt new file mode 100644 index 00000000000000..e306f657fba7dd --- /dev/null +++ b/Documentation/config/sendpack.txt @@ -0,0 +1,5 @@ +sendpack.sideband:: + Allows to disable the side-band-64k capability for send-pack even + when it is advertised by the server. Makes it possible to work + around a limitation in the git for windows implementation together + with the dump git protocol. Defaults to true. diff --git a/send-pack.c b/send-pack.c index fa2f5eec17bba1..f9e6255ee13328 100644 --- a/send-pack.c +++ b/send-pack.c @@ -488,7 +488,7 @@ int send_pack(struct send_pack_args *args, int need_pack_data = 0; int allow_deleting_refs = 0; int status_report = 0; - int use_sideband = 0; + int use_sideband = 1; int quiet_supported = 0; int agent_supported = 0; int advertise_sid = 0; @@ -511,6 +511,7 @@ int send_pack(struct send_pack_args *args, return 0; } + git_config_get_bool("sendpack.sideband", &use_sideband); git_config_get_bool("push.negotiate", &push_negotiate); if (push_negotiate) get_commons_through_negotiation(args->url, remote_refs, &commons); @@ -529,8 +530,7 @@ int send_pack(struct send_pack_args *args, allow_deleting_refs = 1; if (server_supports("ofs-delta")) args->use_ofs_delta = 1; - if (server_supports("side-band-64k")) - use_sideband = 1; + use_sideband = use_sideband && server_supports("side-band-64k"); if (server_supports("quiet")) quiet_supported = 1; if (server_supports("agent"))