{
struct object_directory *odb;
+ obj_read_lock();
for (odb = r->objects->odb; odb; odb = odb->next)
odb_clear_loose_cache(odb);
r->objects->approximate_object_count_valid = 0;
r->objects->packed_git_initialized = 0;
prepare_packed_git(r);
+ obj_read_unlock();
}
struct packed_git *get_packed_git(struct repository *r)
do {
in = use_pack(p, w_curs, curpos, &stream.avail_in);
stream.next_in = in;
+ /*
+ * Note: the window section returned by use_pack() must be
+ * available throughout git_inflate()'s unlocked execution. To
+ * ensure no other thread will modify the window in the
+ * meantime, we rely on the packed_window.inuse_cnt. This
+ * counter is incremented before window reading and checked
+ * before window disposal.
+ *
+ * Other worrying sections could be the call to close_pack_fd(),
+ * which can close packs even with in-use windows, and to
+ * reprepare_packed_git(). Regarding the former, mmap doc says:
+ * "closing the file descriptor does not unmap the region". And
+ * for the latter, it won't re-open already available packs.
+ */
+ obj_read_unlock();
st = git_inflate(&stream, Z_FINISH);
+ obj_read_lock();
curpos += stream.next_in - in;
} while ((st == Z_OK || st == Z_BUF_ERROR) &&
stream.total_out < sizeof(delta_head));
return NULL;
}
-static off_t get_delta_base(struct packed_git *p,
- struct pack_window **w_curs,
- off_t *curpos,
- enum object_type type,
- off_t delta_obj_offset)
+off_t get_delta_base(struct packed_git *p,
+ struct pack_window **w_curs,
+ off_t *curpos,
+ enum object_type type,
+ off_t delta_obj_offset)
{
unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
off_t base_offset;
* the final object lookup), but more expensive for OFS deltas (we
* have to load the revidx to convert the offset back into a sha1).
*/
-static const unsigned char *get_delta_base_sha1(struct packed_git *p,
- struct pack_window **w_curs,
- off_t curpos,
- enum object_type type,
- off_t delta_obj_offset)
+static int get_delta_base_oid(struct packed_git *p,
+ struct pack_window **w_curs,
+ off_t curpos,
+ struct object_id *oid,
+ enum object_type type,
+ off_t delta_obj_offset)
{
if (type == OBJ_REF_DELTA) {
unsigned char *base = use_pack(p, w_curs, curpos, NULL);
- return base;
+ oidread(oid, base);
+ return 0;
} else if (type == OBJ_OFS_DELTA) {
struct revindex_entry *revidx;
off_t base_offset = get_delta_base(p, w_curs, &curpos,
type, delta_obj_offset);
if (!base_offset)
- return NULL;
+ return -1;
revidx = find_pack_revindex(p, base_offset);
if (!revidx)
- return NULL;
+ return -1;
- return nth_packed_object_sha1(p, revidx->nr);
+ return nth_packed_object_id(oid, p, revidx->nr);
} else
- return NULL;
+ return -1;
}
static int retry_bad_packed_offset(struct repository *r,
revidx = find_pack_revindex(p, obj_offset);
if (!revidx)
return OBJ_BAD;
- nth_packed_object_oid(&oid, p, revidx->nr);
+ nth_packed_object_id(&oid, p, revidx->nr);
mark_bad_packed_object(p, oid.hash);
type = oid_object_info(r, &oid, NULL);
if (type <= OBJ_NONE)
struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
struct list_head *lru, *tmp;
+ /*
+ * Check required to avoid redundant entries when more than one thread
+ * is unpacking the same object, in unpack_entry() (since its phases I
+ * and III might run concurrently across multiple threads).
+ */
+ if (in_delta_base_cache(p, base_offset))
+ return;
+
delta_base_cached += base_size;
list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
}
}
- if (oi->delta_base_sha1) {
+ if (oi->delta_base_oid) {
if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
- const unsigned char *base;
-
- base = get_delta_base_sha1(p, &w_curs, curpos,
- type, obj_offset);
- if (!base) {
+ if (get_delta_base_oid(p, &w_curs, curpos,
+ oi->delta_base_oid,
+ type, obj_offset) < 0) {
type = OBJ_BAD;
goto out;
}
-
- hashcpy(oi->delta_base_sha1, base);
} else
- hashclr(oi->delta_base_sha1);
+ oidclr(oi->delta_base_oid);
}
oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
do {
in = use_pack(p, w_curs, curpos, &stream.avail_in);
stream.next_in = in;
+ /*
+ * Note: we must ensure the window section returned by
+ * use_pack() will be available throughout git_inflate()'s
+ * unlocked execution. Please refer to the comment at
+ * get_size_from_delta() to see how this is done.
+ */
+ obj_read_unlock();
st = git_inflate(&stream, Z_FINISH);
+ obj_read_lock();
if (!stream.avail_out)
break; /* the payload is larger than it should be */
curpos += stream.next_in - in;
off_t len = revidx[1].offset - obj_offset;
if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
struct object_id oid;
- nth_packed_object_oid(&oid, p, revidx->nr);
+ nth_packed_object_id(&oid, p, revidx->nr);
error("bad packed object CRC for %s",
oid_to_hex(&oid));
mark_bad_packed_object(p, oid.hash);
struct object_id base_oid;
revidx = find_pack_revindex(p, obj_offset);
if (revidx) {
- nth_packed_object_oid(&base_oid, p, revidx->nr);
+ nth_packed_object_id(&base_oid, p, revidx->nr);
error("failed to read delta base object %s"
" at offset %"PRIuMAX" from %s",
oid_to_hex(&base_oid), (uintmax_t)obj_offset,
index_lookup, index_lookup_width, result);
}
-const unsigned char *nth_packed_object_sha1(struct packed_git *p,
- uint32_t n)
+int nth_packed_object_id(struct object_id *oid,
+ struct packed_git *p,
+ uint32_t n)
{
const unsigned char *index = p->index_data;
const unsigned int hashsz = the_hash_algo->rawsz;
if (!index) {
if (open_pack_index(p))
- return NULL;
+ return -1;
index = p->index_data;
}
if (n >= p->num_objects)
- return NULL;
+ return -1;
index += 4 * 256;
if (p->index_version == 1) {
- return index + (hashsz + 4) * n + 4;
+ oidread(oid, index + (hashsz + 4) * n + 4);
} else {
index += 8;
- return index + hashsz * n;
+ oidread(oid, index + hashsz * n);
}
-}
-
-const struct object_id *nth_packed_object_oid(struct object_id *oid,
- struct packed_git *p,
- uint32_t n)
-{
- const unsigned char *hash = nth_packed_object_sha1(p, n);
- if (!hash)
- return NULL;
- hashcpy(oid->hash, hash);
- return oid;
+ return 0;
}
void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
else
pos = i;
- if (!nth_packed_object_oid(&oid, p, pos))
+ if (nth_packed_object_id(&oid, p, pos) < 0)
return error("unable to get sha1 of object %u in %s",
pos, p->pack_name);
projects / thirdparty / git.git / blobdiff