[PATCH 1/1] pack-write, pack-bitmap-write: register tmp pack files for cleanup

[Royce Remer <royceremer@gmail.com>]

`git repack` correctly uses `register_tempfile()` via
`collect_pack_filenames()` for the `.tmp-<pid>-pack-*` files it
creates, so they are removed when the process exits gracefully.

The lower-level pack-writing functions invoked by `git gc` and
`git maintenance` do not. They call `odb_mkstemp()` which wraps
`mkstemp(2)` directly, bypassing the tempfile subsystem entirely.
A SIGTERM leaves these files stranded on disk where they accumulate
and can exhaust available space:

  objects/pack/tmp_pack_XXXXXX   (create_tmp_packfile)
  objects/pack/tmp_idx_XXXXXX    (write_idx_file)
  objects/pack/tmp_rev_XXXXXX    (write_rev_file_order)
  objects/pack/tmp_mtimes_XXXXXX (write_mtimes_file)
  objects/pack/tmp_bitmap_XXXXXX (bitmap_writer_finish)

Call `register_tempfile()` immediately after each `odb_mkstemp()` so
that the atexit(3) and signal handlers unlink the file on abnormal
exit.

Signed-off-by: Royce Remer <royceremer@gmail.com>
---
 pack-bitmap-write.c | 3 +++
 pack-write.c        | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c
index 1bcb3f98a4..c566419690 100644
--- a/pack-bitmap-write.c
+++ b/pack-bitmap-write.c
@@ -23,6 +23,7 @@
 #include "oid-array.h"
 #include "config.h"
 #include "alloc.h"
+#include "tempfile.h"
 #include "refs.h"
 #include "strmap.h"
 #include "midx.h"
@@ -1378,6 +1379,7 @@ void bitmap_writer_finish(struct bitmap_writer *writer,
 
 	int fd = odb_mkstemp(writer->repo->objects, &tmp_file,
 			     "pack/tmp_bitmap_XXXXXX");
+	struct tempfile *tmp = register_tempfile(tmp_file.buf);
 
 	if (writer->pseudo_merges_nr)
 		options |= BITMAP_OPT_PSEUDO_MERGES;
@@ -1435,6 +1437,7 @@ void bitmap_writer_finish(struct bitmap_writer *writer,
 
 	if (rename(tmp_file.buf, filename))
 		die_errno("unable to rename temporary bitmap file to '%s'", filename);
+	delete_tempfile(&tmp);
 
 	strbuf_release(&tmp_file);
 	free(offsets);
diff --git a/pack-write.c b/pack-write.c
index 83eaf88541..fa6b532230 100644
--- a/pack-write.c
+++ b/pack-write.c
@@ -13,6 +13,7 @@
 #include "path.h"
 #include "repository.h"
 #include "strbuf.h"
+#include "tempfile.h"
 
 void reset_pack_idx_option(struct pack_idx_option *opts)
 {
@@ -87,6 +88,7 @@ const char *write_idx_file(struct repository *repo,
 			fd = odb_mkstemp(repo->objects, &tmp_file,
 					 "pack/tmp_idx_XXXXXX");
 			index_name = strbuf_detach(&tmp_file, NULL);
+			(void)register_tempfile(index_name);
 		} else {
 			unlink(index_name);
 			fd = xopen(index_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
@@ -263,6 +265,7 @@ char *write_rev_file_order(struct repository *repo,
 			fd = odb_mkstemp(repo->objects, &tmp_file,
 					 "pack/tmp_rev_XXXXXX");
 			path = strbuf_detach(&tmp_file, NULL);
+			(void)register_tempfile(path);
 		} else {
 			unlink(rev_name);
 			fd = xopen(rev_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
@@ -346,6 +349,7 @@ static char *write_mtimes_file(struct repository *repo,
 
 	fd = odb_mkstemp(repo->objects, &tmp_file, "pack/tmp_mtimes_XXXXXX");
 	mtimes_name = strbuf_detach(&tmp_file, NULL);
+	(void)register_tempfile(mtimes_name);
 	f = hashfd(repo->hash_algo, fd, mtimes_name);
 
 	write_mtimes_header(repo->hash_algo, f);
@@ -535,6 +539,7 @@ struct hashfile *create_tmp_packfile(struct repository *repo,
 
 	fd = odb_mkstemp(repo->objects, &tmpname, "pack/tmp_pack_XXXXXX");
 	*pack_tmp_name = strbuf_detach(&tmpname, NULL);
+	(void)register_tempfile(*pack_tmp_name);
 	return hashfd(repo->hash_algo, fd, *pack_tmp_name);
 }
 
-- 
2.55.0.1.ga30d533ec0