git/reachable.c
Phillip Wood bc7f5db896 prune: mark rebase autostash and orig-head as reachable
Rebase records the oid of HEAD before rebasing and the commit created by
"--autostash" in files in the rebase state directory. This means that
the autostash commit is never reachable from any ref or reflog and when
rebasing a detached HEAD the original HEAD can become unreachable if the
user expires HEAD's the reflog while the rebase is running. Fix this by
reading the relevant files when marking reachable commits.

Note that it is possible for the commit recorded in
.git/rebase-merge/amend to be unreachable but pruning that object does
not affect the operation of "git rebase --continue" as we're only
interested in the object id, not in the object itself.

Reported-by: Orgad Shaneh <orgads@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-09 10:04:59 -08:00

404 lines
9.4 KiB
C

#include "git-compat-util.h"
#include "gettext.h"
#include "hex.h"
#include "refs.h"
#include "commit.h"
#include "blob.h"
#include "diff.h"
#include "revision.h"
#include "reachable.h"
#include "cache-tree.h"
#include "progress.h"
#include "list-objects.h"
#include "packfile.h"
#include "worktree.h"
#include "object-store-ll.h"
#include "pack-bitmap.h"
#include "pack-mtimes.h"
#include "config.h"
#include "run-command.h"
#include "sequencer.h"
struct connectivity_progress {
struct progress *progress;
unsigned long count;
};
static void update_progress(struct connectivity_progress *cp)
{
cp->count++;
if ((cp->count & 1023) == 0)
display_progress(cp->progress, cp->count);
}
static void add_one_file(const char *path, struct rev_info *revs)
{
struct strbuf buf = STRBUF_INIT;
struct object_id oid;
struct object *object;
if (!read_oneliner(&buf, path, READ_ONELINER_SKIP_IF_EMPTY)) {
strbuf_release(&buf);
return;
}
strbuf_trim(&buf);
if (!get_oid_hex(buf.buf, &oid)) {
object = parse_object_or_die(&oid, buf.buf);
add_pending_object(revs, object, "");
}
strbuf_release(&buf);
}
/* Mark objects recorded in rebase state files as reachable. */
static void add_rebase_files(struct rev_info *revs)
{
struct strbuf buf = STRBUF_INIT;
size_t len;
const char *path[] = {
"rebase-apply/autostash",
"rebase-apply/orig-head",
"rebase-merge/autostash",
"rebase-merge/orig-head",
};
struct worktree **worktrees = get_worktrees();
for (struct worktree **wt = worktrees; *wt; wt++) {
strbuf_reset(&buf);
strbuf_addstr(&buf, get_worktree_git_dir(*wt));
strbuf_complete(&buf, '/');
len = buf.len;
for (size_t i = 0; i < ARRAY_SIZE(path); i++) {
strbuf_setlen(&buf, len);
strbuf_addstr(&buf, path[i]);
add_one_file(buf.buf, revs);
}
}
strbuf_release(&buf);
free_worktrees(worktrees);
}
static int add_one_ref(const char *path, const struct object_id *oid,
int flag, void *cb_data)
{
struct rev_info *revs = (struct rev_info *)cb_data;
struct object *object;
if ((flag & REF_ISSYMREF) && (flag & REF_ISBROKEN)) {
warning("symbolic ref is dangling: %s", path);
return 0;
}
object = parse_object_or_die(oid, path);
add_pending_object(revs, object, "");
return 0;
}
/*
* The traversal will have already marked us as SEEN, so we
* only need to handle any progress reporting here.
*/
static void mark_object(struct object *obj UNUSED,
const char *name UNUSED,
void *data)
{
update_progress(data);
}
static void mark_commit(struct commit *c, void *data)
{
mark_object(&c->object, NULL, data);
}
struct recent_data {
struct rev_info *revs;
timestamp_t timestamp;
report_recent_object_fn *cb;
int ignore_in_core_kept_packs;
struct oidset extra_recent_oids;
int extra_recent_oids_loaded;
};
static int run_one_gc_recent_objects_hook(struct oidset *set,
const char *args)
{
struct child_process cmd = CHILD_PROCESS_INIT;
struct strbuf buf = STRBUF_INIT;
FILE *out;
int ret = 0;
cmd.use_shell = 1;
cmd.out = -1;
strvec_push(&cmd.args, args);
if (start_command(&cmd))
return -1;
out = xfdopen(cmd.out, "r");
while (strbuf_getline(&buf, out) != EOF) {
struct object_id oid;
const char *rest;
if (parse_oid_hex(buf.buf, &oid, &rest) || *rest) {
ret = error(_("invalid extra cruft tip: '%s'"), buf.buf);
break;
}
oidset_insert(set, &oid);
}
fclose(out);
ret |= finish_command(&cmd);
strbuf_release(&buf);
return ret;
}
static void load_gc_recent_objects(struct recent_data *data)
{
const struct string_list *programs;
int ret = 0;
size_t i;
data->extra_recent_oids_loaded = 1;
if (git_config_get_string_multi("gc.recentobjectshook", &programs))
return;
for (i = 0; i < programs->nr; i++) {
ret = run_one_gc_recent_objects_hook(&data->extra_recent_oids,
programs->items[i].string);
if (ret)
die(_("unable to enumerate additional recent objects"));
}
}
static int obj_is_recent(const struct object_id *oid, timestamp_t mtime,
struct recent_data *data)
{
if (mtime > data->timestamp)
return 1;
if (!data->extra_recent_oids_loaded)
load_gc_recent_objects(data);
return oidset_contains(&data->extra_recent_oids, oid);
}
static void add_recent_object(const struct object_id *oid,
struct packed_git *pack,
off_t offset,
timestamp_t mtime,
struct recent_data *data)
{
struct object *obj;
enum object_type type;
if (!obj_is_recent(oid, mtime, data))
return;
/*
* We do not want to call parse_object here, because
* inflating blobs and trees could be very expensive.
* However, we do need to know the correct type for
* later processing, and the revision machinery expects
* commits and tags to have been parsed.
*/
type = oid_object_info(the_repository, oid, NULL);
if (type < 0)
die("unable to get object info for %s", oid_to_hex(oid));
switch (type) {
case OBJ_TAG:
case OBJ_COMMIT:
obj = parse_object_or_die(oid, NULL);
break;
case OBJ_TREE:
obj = (struct object *)lookup_tree(the_repository, oid);
break;
case OBJ_BLOB:
obj = (struct object *)lookup_blob(the_repository, oid);
break;
default:
die("unknown object type for %s: %s",
oid_to_hex(oid), type_name(type));
}
if (!obj)
die("unable to lookup %s", oid_to_hex(oid));
add_pending_object(data->revs, obj, "");
if (data->cb)
data->cb(obj, pack, offset, mtime);
}
static int want_recent_object(struct recent_data *data,
const struct object_id *oid)
{
if (data->ignore_in_core_kept_packs &&
has_object_kept_pack(oid, IN_CORE_KEEP_PACKS))
return 0;
return 1;
}
static int add_recent_loose(const struct object_id *oid,
const char *path, void *data)
{
struct stat st;
struct object *obj;
if (!want_recent_object(data, oid))
return 0;
obj = lookup_object(the_repository, oid);
if (obj && obj->flags & SEEN)
return 0;
if (stat(path, &st) < 0) {
/*
* It's OK if an object went away during our iteration; this
* could be due to a simultaneous repack. But anything else
* we should abort, since we might then fail to mark objects
* which should not be pruned.
*/
if (errno == ENOENT)
return 0;
return error_errno("unable to stat %s", oid_to_hex(oid));
}
add_recent_object(oid, NULL, 0, st.st_mtime, data);
return 0;
}
static int add_recent_packed(const struct object_id *oid,
struct packed_git *p,
uint32_t pos,
void *data)
{
struct object *obj;
timestamp_t mtime = p->mtime;
if (!want_recent_object(data, oid))
return 0;
obj = lookup_object(the_repository, oid);
if (obj && obj->flags & SEEN)
return 0;
if (p->is_cruft) {
if (load_pack_mtimes(p) < 0)
die(_("could not load cruft pack .mtimes"));
mtime = nth_packed_mtime(p, pos);
}
add_recent_object(oid, p, nth_packed_object_offset(p, pos), mtime, data);
return 0;
}
int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
timestamp_t timestamp,
report_recent_object_fn *cb,
int ignore_in_core_kept_packs)
{
struct recent_data data;
enum for_each_object_flags flags;
int r;
data.revs = revs;
data.timestamp = timestamp;
data.cb = cb;
data.ignore_in_core_kept_packs = ignore_in_core_kept_packs;
oidset_init(&data.extra_recent_oids, 0);
data.extra_recent_oids_loaded = 0;
r = for_each_loose_object(add_recent_loose, &data,
FOR_EACH_OBJECT_LOCAL_ONLY);
if (r)
goto done;
flags = FOR_EACH_OBJECT_LOCAL_ONLY | FOR_EACH_OBJECT_PACK_ORDER;
if (ignore_in_core_kept_packs)
flags |= FOR_EACH_OBJECT_SKIP_IN_CORE_KEPT_PACKS;
r = for_each_packed_object(add_recent_packed, &data, flags);
done:
oidset_clear(&data.extra_recent_oids);
return r;
}
static int mark_object_seen(const struct object_id *oid,
enum object_type type,
int exclude UNUSED,
uint32_t name_hash UNUSED,
struct packed_git *found_pack UNUSED,
off_t found_offset UNUSED)
{
struct object *obj = lookup_object_by_type(the_repository, oid, type);
if (!obj)
die("unable to create object '%s'", oid_to_hex(oid));
obj->flags |= SEEN;
return 0;
}
void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
timestamp_t mark_recent, struct progress *progress)
{
struct connectivity_progress cp;
struct bitmap_index *bitmap_git;
/*
* Set up revision parsing, and mark us as being interested
* in all object types, not just commits.
*/
revs->tag_objects = 1;
revs->blob_objects = 1;
revs->tree_objects = 1;
/* Add all refs from the index file */
add_index_objects_to_pending(revs, 0);
/* Add all external refs */
for_each_ref(add_one_ref, revs);
/* detached HEAD is not included in the list above */
head_ref(add_one_ref, revs);
other_head_refs(add_one_ref, revs);
/* rebase autostash and orig-head */
add_rebase_files(revs);
/* Add all reflog info */
if (mark_reflog)
add_reflogs_to_pending(revs, 0);
cp.progress = progress;
cp.count = 0;
bitmap_git = prepare_bitmap_walk(revs, 0);
if (bitmap_git) {
traverse_bitmap_commit_list(bitmap_git, revs, mark_object_seen);
free_bitmap_index(bitmap_git);
} else {
if (prepare_revision_walk(revs))
die("revision walk setup failed");
traverse_commit_list(revs, mark_commit, mark_object, &cp);
}
if (mark_recent) {
revs->ignore_missing_links = 1;
if (add_unseen_recent_objects_to_traversal(revs, mark_recent,
NULL, 0))
die("unable to mark recent objects");
if (prepare_revision_walk(revs))
die("revision walk setup failed");
traverse_commit_list(revs, mark_commit, mark_object, &cp);
}
display_progress(cp.progress, cp.count);
}