Junio, Brian,
it seems that the stability of the "git tar" output is broken.
On Mon, Oct 20, 2014 at 4:59 AM, Konstantin Ryabitsev
<konstantin@xxxxxxxxxxxxxxxxxxx> wrote:
>
> Looks like 3.18-rc1 upload didn't work:
>
> This is why the front page still lists 3.17 as the latest mainline. Want
> to try again?
Ok, tried again, and failed again.
> If that still doesn't work, you may have to use version 1.7 of git when
> generating the tarball and signature -- I recall Greg having a similar
> problem in the past.
Ugh, yes, that seems to be it. Current git generates different
tar-files than older releases do:
tar-1.7.9.7 tar-cur differ: byte 107, line 1
and a quick bisection shows that it is due to commit 10f343ea814f
("archive: honor tar.umask even for pax headers") in the current git
development version.
Junio, quite frankly, I don't think that that fix was a good idea. I'd
suggest having a *separate* umask for the pax headers, so that we do
not break this long-lasting stability of "git archive" output in ways
that are unfixable and not compatible. kernel.org has relied (for a
*long* time) on being able to just upload the signature of the
resulting tar-file, because both sides can generate the same tar-fiel
bit-for-bit.
So instead of using "tar_umask", please make it use "tar_pax_umask",
and have that default to 000. Ok?
Something like the attached patch.
Or just revert 10f343ea814f entirely.
Linus
From d5ca7ae0a34e31c48397f59b03ecabda7c5c40b2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Mon, 20 Oct 2014 08:21:38 -0700
Subject: [PATCH] Don't use the default 'tar.umask' for pax headers
That wasn't the original behavior, and doing so breaks the fact that
tar-files are bit-for-bit compatible across git versions.
If you really want to work around broken receiving tar implementations
(dubious, we've not needed to do so before), use "[tar] paxumask" in the
git config file. Or maybe we could expose some command line flag to do
so. But don't break existing format compatibility for dubious gains.
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
---
archive-tar.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/archive-tar.c b/archive-tar.c
index df2f4c8a6437..40139ea4ee4e 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -14,6 +14,7 @@ static char block[BLOCKSIZE];
static unsigned long offset;
static int tar_umask = 002;
+static int tar_pax_umask = 000;
static int write_tar_filter_archive(const struct archiver *ar,
struct archiver_args *args);
@@ -192,7 +193,7 @@ static int write_extended_header(struct archiver_args *args,
unsigned int mode;
memset(&header, 0, sizeof(header));
*header.typeflag = TYPEFLAG_EXT_HEADER;
- mode = 0100666 & ~tar_umask;
+ mode = 0100666 & ~tar_pax_umask;
sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
prepare_header(args, &header, mode, size);
write_blocked(&header, sizeof(header));
@@ -300,7 +301,7 @@ static int write_global_extended_header(struct archiver_args *args)
strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
memset(&header, 0, sizeof(header));
*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
- mode = 0100666 & ~tar_umask;
+ mode = 0100666 & ~tar_pax_umask;
strcpy(header.name, "pax_global_header");
prepare_header(args, &header, mode, ext_header.len);
write_blocked(&header, sizeof(header));
@@ -374,6 +375,15 @@ static int git_tar_config(const char *var, const char *value, void *cb)
return 0;
}
+ if (!strcmp(var, "tar.paxumask")) {
+ if (value && !strcmp(value, "user")) {
+ tar_pax_umask = umask(0);
+ } else {
+ tar_pax_umask = git_config_int(var, value);
+ }
+ return 0;
+ }
+
return tar_filter_config(var, value, cb);
}
--
2.1.2.330.g565301e