[PATCH v2 2/2] builtin/repack.c: avoid dir traversal in `collect_pack_filenames()`
When repacking, the function `collect_pack_filenames()` is responsible for collecting the set of existing packs in the repository, and partitioning them into "kept" (if the pack has a ".keep" file or was given via `--keep-pack`) and "nonkept" (otherwise) lists.
This function comes from the original C port of git-repack.sh from back in a1bbc6c0176 (repack: rewrite the shell script in C, 2013-09-15), where it first appears as `get_non_kept_pack_filenames()`. At the time, the implementation was a fairly direct translation from the relevant portion of git-repack.sh, which looped over the results of
find "$PACKDIR" -type f -name '*.pack'
either ignoring the pack as kept, or adding it to the list of existing packs.
So the choice to directly translate this function in terms of `readdir()` in a1bbc6c0176 made sense. At the time, it was possible to refine the C version in terms of packed_git structs, but was never done.
However, manually enumerating a repository's packs via `readdir()` is confusing and error-prone. It leads to frustrating inconsistencies between which packs Git considers to be part of a repository (i.e., could be found in the list of packs from `get_all_packs()`), and which packs `collect_pack_filenames()` considers to meet the same criteria.
This bit us in 73320e49ad (builtin/repack.c: only collect fully-formed packs, 2023-06-07), and again in the previous commit.
Prevent these issues from biting us in the future by implementing the `collect_pack_filenames()` function by looping over an array of pointers to `packed_git` structs, ensuring that we use the same criteria to determine the set of available packs.
One gotcha here is that we have to ignore non-local packs, since the original version of `collect_pack_filenames()` only looks at the local pack directory to collect existing packs.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
builtin/repack.c | 41 +++++++++++++++--------------------------
1 file changed, 15 insertions(+), 26 deletions(-)
Show changes to builtin/repack.c +15 −26
diff --git a/builtin/repack.c b/builtin/repack.c
index 724e09536e..ac9fc61d2e 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -106,49 +106,38 @@ static void collect_pack_filenames(struct string_list *fname_nonkept_list,
struct string_list *fname_kept_list,
const struct string_list *extra_keep)
{
- DIR *dir;
- struct dirent *e;
- char *fname;
+ struct packed_git *p;
struct strbuf buf = STRBUF_INIT;
- if (!(dir = opendir(packdir)))
- return;
-
- while ((e = readdir(dir)) != NULL) {
- size_t len;
+ for (p = get_all_packs(the_repository); p; p = p->next) {
int i;
+ const char *base;
- if (!strip_suffix(e->d_name, ".idx", &len))
+ if (!p->pack_local)
continue;
- strbuf_reset(&buf);
- strbuf_add(&buf, e->d_name, len);
- strbuf_addstr(&buf, ".pack");
-
- if (!file_exists(mkpath("%s/%s", packdir, buf.buf)))
- continue;
+ base = pack_basename(p);
for (i = 0; i < extra_keep->nr; i++)
- if (!fspathcmp(buf.buf, extra_keep->items[i].string))
+ if (!fspathcmp(base, extra_keep->items[i].string))
break;
- fname = xmemdupz(e->d_name, len);
+ strbuf_reset(&buf);
+ strbuf_addstr(&buf, base);
+ strbuf_strip_suffix(&buf, ".pack");
- if ((extra_keep->nr > 0 && i < extra_keep->nr) ||
- (file_exists(mkpath("%s/%s.keep", packdir, fname)))) {
- string_list_append_nodup(fname_kept_list, fname);
- } else {
+ if ((extra_keep->nr > 0 && i < extra_keep->nr) || p->pack_keep)
+ string_list_append(fname_kept_list, buf.buf);
+ else {
struct string_list_item *item;
- item = string_list_append_nodup(fname_nonkept_list,
- fname);
- if (file_exists(mkpath("%s/%s.mtimes", packdir, fname)))
+ item = string_list_append(fname_nonkept_list, buf.buf);
+ if (p->is_cruft)
item->util = (void*)(uintptr_t)CRUFT_PACK;
}
}
- closedir(dir);
- strbuf_release(&buf);
string_list_sort(fname_kept_list);
+ strbuf_release(&buf);
}
static void remove_redundant_pack(const char *dir_name, const char *base_name)
--
2.41.0.329.gffdf85f6d39
Taylor Blau