Unverified Commit e6d9398c authored by Konstantin Komarov's avatar Konstantin Komarov
Browse files

fs/ntfs3: Check possible errors in run_pack in advance 



Checking in advance speeds things up in some cases.

Signed-off-by: default avatarKonstantin Komarov <almaz.alexandrovich@paragon-software.com>
parent 54033c13

fs/ntfs3/run.c

+22 −17
Original line number Diff line number Diff line
@@ -820,26 +820,36 @@ int run_pack(const struct runs_tree *run, CLST svcn, CLST len, u8 *run_buf, 
	CLST next_vcn, vcn, lcn;

	CLST prev_lcn = 0;

	CLST evcn1 = svcn + len;

	const struct ntfs_run *r, *r_end;

	int packed_size = 0;

	size_t i;

	bool ok;

	s64 dlcn;

	int offset_size, size_size, tmp;



	next_vcn = vcn = svcn;



	*packed_vcns = 0;



	if (!len)

		goto out;



	ok = run_lookup_entry(run, vcn, &lcn, &len, &i);

	/* Check all required entries [svcn, encv1) available. */

	if (!run_lookup(run, svcn, &i))

		return -ENOENT;



	r_end = run->runs + run->count;

	r = run->runs + i;



	if (!ok)

		goto error;

	for (next_vcn = r->vcn + r->len; next_vcn < evcn1;

	     next_vcn = r->vcn + r->len) {

		if (++r >= r_end || r->vcn != next_vcn)

			return -ENOENT;

	}



	if (next_vcn != vcn)

		goto error;

	/* Repeat cycle above and pack runs. Assume no errors. */

	r = run->runs + i;

	len = svcn - r->vcn;

	vcn = svcn;

	lcn = r->lcn == SPARSE_LCN ? SPARSE_LCN : (r->lcn + len);

	len = r->len - len;



	for (;;) {

		next_vcn = vcn + len;
@@ -888,12 +898,10 @@ int run_pack(const struct runs_tree *run, CLST svcn, CLST len, u8 *run_buf, 
		if (packed_size + 1 >= run_buf_size || next_vcn >= evcn1)

			goto out;



		ok = run_get_entry(run, ++i, &vcn, &lcn, &len);

		if (!ok)

			goto error;



		if (next_vcn != vcn)

			goto error;

		r += 1;

		vcn = r->vcn;

		lcn = r->lcn;

		len = r->len;

	}



out:
@@ -902,9 +910,6 @@ int run_pack(const struct runs_tree *run, CLST svcn, CLST len, u8 *run_buf, 
		run_buf[0] = 0;



	return packed_size + 1;



error:

	return -EOPNOTSUPP;

}



/*