dilim/git
1
0
Fork 0
mirror of https://github.com/git/git.git synced 2026-08-08 09:02:01 +00:00
Code Issues Packages Projects Releases Wiki Activity

http: permit unlinking partial packs on Windows

Browse Source 
On Windows, an open file must permit FILE_SHARE_DELETE before another
process can unlink it. MinGW's non-append O_RDWR open enables that
sharing mode only for an existing file; adding O_CREAT falls back to
_wopen(), which cannot set it.

First try opening the partial pack without O_CREAT. If it does not
exist, create it exclusively, close that descriptor, and retry through
the existing-file path. A racing creator retries after EEXIST.

This ensures that every retained descriptor permits another downloader
to unlink the staging path. Add an unlink-while-indexing test that does
not require FIFOs and can therefore run on MinGW.

Signed-off-by: Ted Nyman <tnyman@openai.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Ted Nyman
2026-07-26 17:28:42 -07:00
committed by Junio C Hamano
parent 5e855d9b42
commit e92a518a74
2 changed files with 37 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
http.c
View File

@@ -2746,7 +2746,22 @@ struct http_pack_request *new_direct_http_pack_request(
odb_pack_name(the_repository, &preq->tmpfile, packed_git_hash, "pack");
strbuf_addstr(&preq->tmpfile, ".temp");
fd = open(preq->tmpfile.buf, O_RDWR | O_CREAT, 0666);
/*
* MinGW's non-append O_RDWR open grants FILE_SHARE_DELETE only for an
* existing file; reopen a newly created file so others may unlink it.
*/
for (;;) {
fd = open(preq->tmpfile.buf, O_RDWR);
if (fd >= 0 || errno != ENOENT)
break;
fd = open(preq->tmpfile.buf, O_RDWR | O_CREAT | O_EXCL, 0666);
if (fd >= 0) {
close(fd);
continue;
}
if (errno != EEXIST)
break;
}
if (fd < 0) {
error_errno("unable to open local file %s for pack",
preq->tmpfile.buf);

21
t/t5550-http-fetch-dumb.sh
View File

@@ -328,6 +328,27 @@ test_expect_success 'http-fetch --packfile resumes a partial download' '
git -C packfileclient-resume cat-file -e "$HASH"
'
test_expect_success 'http-fetch --packfile permits unlink while indexing' '
git init packfileclient-unlink &&
p=$(cd "$HTTPD_DOCUMENT_ROOT_PATH"/repo_pack.git &&
ls objects/pack/pack-*.pack) &&
tmpfile="packfileclient-unlink/.git/objects/pack/pack-$ARBITRARY.pack.temp" &&
write_script git-unlink-index-pack <<-\EOF &&
test -f "$GIT_TEST_PACK_TEMP" || exit 1
rm "$GIT_TEST_PACK_TEMP" || exit 1
exec git index-pack "$@"
EOF
test_when_finished "rm -f git-unlink-index-pack" &&
PATH="$TRASH_DIRECTORY:$PATH" \
GIT_TEST_PACK_TEMP="$TRASH_DIRECTORY/$tmpfile" \
git -C packfileclient-unlink http-fetch --packfile="$ARBITRARY" \
--index-pack-arg=unlink-index-pack \
--index-pack-arg=--stdin --index-pack-arg=--keep \
"$HTTPD_URL/dumb/repo_pack.git/$p" >out &&
test_path_is_missing "$tmpfile" &&
git -C packfileclient-unlink cat-file -e "$HASH"
'
test_expect_success PERL,PIPE 'concurrent http-fetch --packfile cannot corrupt an overlapping download' '
git init packfileclient-overlap &&
blob=$(test-tool genrandom pack-overlap 2m |