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Commit abc6e134 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: fix key checks and advance in the search ioctl 



The search ioctl was working well for finding tree roots, but using it for
generic searches requires a few changes to how the keys are advanced.
This treats the search control min fields for objectid, type and offset
more like a key, where we drop the offset to zero once we bump the type,
etc.

The downside of this is that we are changing the min_type and min_offset
fields during the search, and so the ioctl caller needs extra checks to make sure
the keys in the result are the ones it wanted.

This also changes key_in_sk to use btrfs_comp_cpu_keys, just to make
things more readable.

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 7fde62bf

fs/btrfs/ioctl.c

+25 −14
Original line number Diff line number Diff line
@@ -914,17 +914,23 @@ out: 
static noinline int key_in_sk(struct btrfs_key *key,

			      struct btrfs_ioctl_search_key *sk)

{

	if (key->objectid < sk->min_objectid)

		return 0;

	if (key->offset < sk->min_offset)

		return 0;

	if (key->type < sk->min_type)

		return 0;

	if (key->objectid > sk->max_objectid)

		return 0;

	if (key->type > sk->max_type)

	struct btrfs_key test;

	int ret;



	test.objectid = sk->min_objectid;

	test.type = sk->min_type;

	test.offset = sk->min_offset;



	ret = btrfs_comp_cpu_keys(key, &test);

	if (ret < 0)

		return 0;

	if (key->offset > sk->max_offset)



	test.objectid = sk->max_objectid;

	test.type = sk->max_type;

	test.offset = sk->max_offset;



	ret = btrfs_comp_cpu_keys(key, &test);

	if (ret > 0)

		return 0;

	return 1;

}
@@ -998,13 +1004,18 @@ static noinline int copy_to_sk(struct btrfs_root *root, 
			break;

	}

advance_key:

	if (key->offset < (u64)-1)

	ret = 0;

	if (key->offset < (u64)-1 && key->offset < sk->max_offset)

		key->offset++;

	else if (key->type < (u8)-1)

	else if (key->type < (u8)-1 && key->type < sk->max_type) {

		key->offset = 0;

		key->type++;

	else if (key->objectid < (u64)-1)

	} else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {

		key->offset = 0;

		key->type = 0;

		key->objectid++;

	ret = 0;

	} else

		ret = 1;

overflow:

	*num_found += found;

	return ret;