[deliverable/linux.git] / fs / btrfs / uuid-tree.c

/*
 * Copyright (C) STRATO AG 2013.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */
#include <linux/uuid.h>
#include <asm/unaligned.h>
#include "ctree.h"
#include "transaction.h"
#include "disk-io.h"
#include "print-tree.h"


static void btrfs_uuid_to_key(u8 *uuid, u8 type, struct btrfs_key *key)
{
	key->type = type;
	key->objectid = get_unaligned_le64(uuid);
	key->offset = get_unaligned_le64(uuid + sizeof(u64));
}

/* return -ENOENT for !found, < 0 for errors, or 0 if an item was found */
static int btrfs_uuid_tree_lookup(struct btrfs_root *uuid_root, u8 *uuid,
				  u8 type, u64 subid)
{
	int ret;
	struct btrfs_path *path = NULL;
	struct extent_buffer *eb;
	int slot;
	u32 item_size;
	unsigned long offset;
	struct btrfs_key key;

	if (WARN_ON_ONCE(!uuid_root)) {
		ret = -ENOENT;
		goto out;
	}

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	btrfs_uuid_to_key(uuid, type, &key);
	ret = btrfs_search_slot(NULL, uuid_root, &key, path, 0, 0);
	if (ret < 0) {
		goto out;
	} else if (ret > 0) {
		ret = -ENOENT;
		goto out;
	}

	eb = path->nodes[0];
	slot = path->slots[0];
	item_size = btrfs_item_size_nr(eb, slot);
	offset = btrfs_item_ptr_offset(eb, slot);
	ret = -ENOENT;

	if (!IS_ALIGNED(item_size, sizeof(u64))) {
		btrfs_warn(uuid_root->fs_info, "uuid item with illegal size %lu!",
			(unsigned long)item_size);
		goto out;
	}
	while (item_size) {
		__le64 data;

		read_extent_buffer(eb, &data, offset, sizeof(data));
		if (le64_to_cpu(data) == subid) {
			ret = 0;
			break;
		}
		offset += sizeof(data);
		item_size -= sizeof(data);
	}

out:
	btrfs_free_path(path);
	return ret;
}

int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans,
			struct btrfs_root *uuid_root, u8 *uuid, u8 type,
			u64 subid_cpu)
{
	int ret;
	struct btrfs_path *path = NULL;
	struct btrfs_key key;
	struct extent_buffer *eb;
	int slot;
	unsigned long offset;
	__le64 subid_le;

	ret = btrfs_uuid_tree_lookup(uuid_root, uuid, type, subid_cpu);
	if (ret != -ENOENT)
		return ret;

	if (WARN_ON_ONCE(!uuid_root)) {
		ret = -EINVAL;
		goto out;
	}

	btrfs_uuid_to_key(uuid, type, &key);

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	ret = btrfs_insert_empty_item(trans, uuid_root, path, &key,
				      sizeof(subid_le));
	if (ret >= 0) {
		/* Add an item for the type for the first time */
		eb = path->nodes[0];
		slot = path->slots[0];
		offset = btrfs_item_ptr_offset(eb, slot);
	} else if (ret == -EEXIST) {
		/*
		 * An item with that type already exists.
		 * Extend the item and store the new subid at the end.
		 */
		btrfs_extend_item(uuid_root, path, sizeof(subid_le));
		eb = path->nodes[0];
		slot = path->slots[0];
		offset = btrfs_item_ptr_offset(eb, slot);
		offset += btrfs_item_size_nr(eb, slot) - sizeof(subid_le);
	} else if (ret < 0) {
		btrfs_warn(uuid_root->fs_info, "insert uuid item failed %d "
			"(0x%016llx, 0x%016llx) type %u!",
			ret, (unsigned long long)key.objectid,
			(unsigned long long)key.offset, type);
		goto out;
	}

	ret = 0;
	subid_le = cpu_to_le64(subid_cpu);
	write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le));
	btrfs_mark_buffer_dirty(eb);

out:
	btrfs_free_path(path);
	return ret;
}

int btrfs_uuid_tree_rem(struct btrfs_trans_handle *trans,
			struct btrfs_root *uuid_root, u8 *uuid, u8 type,
			u64 subid)
{
	int ret;
	struct btrfs_path *path = NULL;
	struct btrfs_key key;
	struct extent_buffer *eb;
	int slot;
	unsigned long offset;
	u32 item_size;
	unsigned long move_dst;
	unsigned long move_src;
	unsigned long move_len;

	if (WARN_ON_ONCE(!uuid_root)) {
		ret = -EINVAL;
		goto out;
	}

	btrfs_uuid_to_key(uuid, type, &key);

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1);
	if (ret < 0) {
		btrfs_warn(uuid_root->fs_info, "error %d while searching for uuid item!",
			ret);
		goto out;
	}
	if (ret > 0) {
		ret = -ENOENT;
		goto out;
	}

	eb = path->nodes[0];
	slot = path->slots[0];
	offset = btrfs_item_ptr_offset(eb, slot);
	item_size = btrfs_item_size_nr(eb, slot);
	if (!IS_ALIGNED(item_size, sizeof(u64))) {
		btrfs_warn(uuid_root->fs_info, "uuid item with illegal size %lu!",
			(unsigned long)item_size);
		ret = -ENOENT;
		goto out;
	}
	while (item_size) {
		__le64 read_subid;

		read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid));
		if (le64_to_cpu(read_subid) == subid)
			break;
		offset += sizeof(read_subid);
		item_size -= sizeof(read_subid);
	}

	if (!item_size) {
		ret = -ENOENT;
		goto out;
	}

	item_size = btrfs_item_size_nr(eb, slot);
	if (item_size == sizeof(subid)) {
		ret = btrfs_del_item(trans, uuid_root, path);
		goto out;
	}

	move_dst = offset;
	move_src = offset + sizeof(subid);
	move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot));
	memmove_extent_buffer(eb, move_dst, move_src, move_len);
	btrfs_truncate_item(uuid_root, path, item_size - sizeof(subid), 1);

out:
	btrfs_free_path(path);
	return ret;
}

static int btrfs_uuid_iter_rem(struct btrfs_root *uuid_root, u8 *uuid, u8 type,
			       u64 subid)
{
	struct btrfs_trans_handle *trans;
	int ret;

	/* 1 - for the uuid item */
	trans = btrfs_start_transaction(uuid_root, 1);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto out;
	}

	ret = btrfs_uuid_tree_rem(trans, uuid_root, uuid, type, subid);
	btrfs_end_transaction(trans, uuid_root);

out:
	return ret;
}

int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info,
			    int (*check_func)(struct btrfs_fs_info *, u8 *, u8,
					      u64))
{
	struct btrfs_root *root = fs_info->uuid_root;
	struct btrfs_key key;
	struct btrfs_path *path;
	int ret = 0;
	struct extent_buffer *leaf;
	int slot;
	u32 item_size;
	unsigned long offset;

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	key.objectid = 0;
	key.type = 0;
	key.offset = 0;

again_search_slot:
	ret = btrfs_search_forward(root, &key, path, 0);
	if (ret) {
		if (ret > 0)
			ret = 0;
		goto out;
	}

	while (1) {
		cond_resched();
		leaf = path->nodes[0];
		slot = path->slots[0];
		btrfs_item_key_to_cpu(leaf, &key, slot);

		if (key.type != BTRFS_UUID_KEY_SUBVOL &&
		    key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
			goto skip;

		offset = btrfs_item_ptr_offset(leaf, slot);
		item_size = btrfs_item_size_nr(leaf, slot);
		if (!IS_ALIGNED(item_size, sizeof(u64))) {
			btrfs_warn(fs_info, "uuid item with illegal size %lu!",
				(unsigned long)item_size);
			goto skip;
		}
		while (item_size) {
			u8 uuid[BTRFS_UUID_SIZE];
			__le64 subid_le;
			u64 subid_cpu;

			put_unaligned_le64(key.objectid, uuid);
			put_unaligned_le64(key.offset, uuid + sizeof(u64));
			read_extent_buffer(leaf, &subid_le, offset,
					   sizeof(subid_le));
			subid_cpu = le64_to_cpu(subid_le);
			ret = check_func(fs_info, uuid, key.type, subid_cpu);
			if (ret < 0)
				goto out;
			if (ret > 0) {
				btrfs_release_path(path);
				ret = btrfs_uuid_iter_rem(root, uuid, key.type,
							  subid_cpu);
				if (ret == 0) {
					/*
					 * this might look inefficient, but the
					 * justification is that it is an
					 * exception that check_func returns 1,
					 * and that in the regular case only one
					 * entry per UUID exists.
					 */
					goto again_search_slot;
				}
				if (ret < 0 && ret != -ENOENT)
					goto out;
			}
			item_size -= sizeof(subid_le);
			offset += sizeof(subid_le);
		}

skip:
		ret = btrfs_next_item(root, path);
		if (ret == 0)
			continue;
		else if (ret > 0)
			ret = 0;
		break;
	}

out:
	btrfs_free_path(path);
	if (ret)
		btrfs_warn(fs_info, "btrfs_uuid_tree_iterate failed %d", ret);
	return 0;
}
Commit	Line	Data
07b30a49 SB	1	/*
	2	* Copyright (C) STRATO AG 2013. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public
	6	* License v2 as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public
	14	* License along with this program; if not, write to the
	15	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	16	* Boston, MA 021110-1307, USA.
	17	*/
	18	#include <linux/uuid.h>
	19	#include <asm/unaligned.h>
	20	#include "ctree.h"
	21	#include "transaction.h"
	22	#include "disk-io.h"
	23	#include "print-tree.h"
	24
	25
	26	static void btrfs_uuid_to_key(u8 uuid, u8 type, struct btrfs_key key)
	27	{
	28	key->type = type;
	29	key->objectid = get_unaligned_le64(uuid);
	30	key->offset = get_unaligned_le64(uuid + sizeof(u64));
	31	}
	32
	33	/* return -ENOENT for !found, < 0 for errors, or 0 if an item was found */
	34	static int btrfs_uuid_tree_lookup(struct btrfs_root uuid_root, u8 uuid,
	35	u8 type, u64 subid)
	36	{
	37	int ret;
	38	struct btrfs_path *path = NULL;
	39	struct extent_buffer *eb;
	40	int slot;
	41	u32 item_size;
	42	unsigned long offset;
	43	struct btrfs_key key;
	44
	45	if (WARN_ON_ONCE(!uuid_root)) {
	46	ret = -ENOENT;
	47	goto out;
	48	}
	49
	50	path = btrfs_alloc_path();
	51	if (!path) {
	52	ret = -ENOMEM;
	53	goto out;
	54	}
	55
	56	btrfs_uuid_to_key(uuid, type, &key);
	57	ret = btrfs_search_slot(NULL, uuid_root, &key, path, 0, 0);
	58	if (ret < 0) {
	59	goto out;
	60	} else if (ret > 0) {
	61	ret = -ENOENT;
	62	goto out;
	63	}
	64
65	eb = path->nodes[0];
66	slot = path->slots[0];
67	item_size = btrfs_item_size_nr(eb, slot);
68	offset = btrfs_item_ptr_offset(eb, slot);
69	ret = -ENOENT;
70
71	if (!IS_ALIGNED(item_size, sizeof(u64))) {
efe120a0	72	btrfs_warn(uuid_root->fs_info, "uuid item with illegal size %lu!",
07b30a49 SB	73	(unsigned long)item_size);
	74	goto out;
	75	}
	76	while (item_size) {
	77	__le64 data;
	78
	79	read_extent_buffer(eb, &data, offset, sizeof(data));
	80	if (le64_to_cpu(data) == subid) {
	81	ret = 0;
	82	break;
	83	}
	84	offset += sizeof(data);
	85	item_size -= sizeof(data);
	86	}
	87
	88	out:
	89	btrfs_free_path(path);
	90	return ret;
	91	}
	92
	93	int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans,
	94	struct btrfs_root uuid_root, u8 uuid, u8 type,
	95	u64 subid_cpu)
	96	{
	97	int ret;
	98	struct btrfs_path *path = NULL;
	99	struct btrfs_key key;
	100	struct extent_buffer *eb;
	101	int slot;
	102	unsigned long offset;
	103	__le64 subid_le;
	104
	105	ret = btrfs_uuid_tree_lookup(uuid_root, uuid, type, subid_cpu);
	106	if (ret != -ENOENT)
	107	return ret;
	108
	109	if (WARN_ON_ONCE(!uuid_root)) {
	110	ret = -EINVAL;
	111	goto out;
	112	}
	113
	114	btrfs_uuid_to_key(uuid, type, &key);
	115
	116	path = btrfs_alloc_path();
	117	if (!path) {
	118	ret = -ENOMEM;
	119	goto out;
	120	}
	121
	122	ret = btrfs_insert_empty_item(trans, uuid_root, path, &key,
	123	sizeof(subid_le));
	124	if (ret >= 0) {
	125	/* Add an item for the type for the first time */
	126	eb = path->nodes[0];
	127	slot = path->slots[0];
	128	offset = btrfs_item_ptr_offset(eb, slot);
	129	} else if (ret == -EEXIST) {
	130	/*
	131	* An item with that type already exists.
	132	* Extend the item and store the new subid at the end.
	133	*/
	134	btrfs_extend_item(uuid_root, path, sizeof(subid_le));
	135	eb = path->nodes[0];
	136	slot = path->slots[0];
137	offset = btrfs_item_ptr_offset(eb, slot);
138	offset += btrfs_item_size_nr(eb, slot) - sizeof(subid_le);
139	} else if (ret < 0) {
efe120a0 FH	140	btrfs_warn(uuid_root->fs_info, "insert uuid item failed %d "
efe120a0 FH	141	"(0x%016llx, 0x%016llx) type %u!",
07b30a49 SB	142	ret, (unsigned long long)key.objectid,
	143	(unsigned long long)key.offset, type);
	144	goto out;
	145	}
	146
	147	ret = 0;
	148	subid_le = cpu_to_le64(subid_cpu);
	149	write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le));
	150	btrfs_mark_buffer_dirty(eb);
	151
	152	out:
	153	btrfs_free_path(path);
	154	return ret;
	155	}
	156
	157	int btrfs_uuid_tree_rem(struct btrfs_trans_handle *trans,
	158	struct btrfs_root uuid_root, u8 uuid, u8 type,
	159	u64 subid)
	160	{
	161	int ret;
	162	struct btrfs_path *path = NULL;
	163	struct btrfs_key key;
	164	struct extent_buffer *eb;
	165	int slot;
	166	unsigned long offset;
	167	u32 item_size;
	168	unsigned long move_dst;
	169	unsigned long move_src;
	170	unsigned long move_len;
	171
	172	if (WARN_ON_ONCE(!uuid_root)) {
	173	ret = -EINVAL;
	174	goto out;
	175	}
	176
	177	btrfs_uuid_to_key(uuid, type, &key);
	178
	179	path = btrfs_alloc_path();
	180	if (!path) {
	181	ret = -ENOMEM;
	182	goto out;
	183	}
	184
	185	ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1);
	186	if (ret < 0) {
efe120a0	187	btrfs_warn(uuid_root->fs_info, "error %d while searching for uuid item!",
07b30a49 SB	188	ret);
	189	goto out;
	190	}
	191	if (ret > 0) {
	192	ret = -ENOENT;
	193	goto out;
	194	}
	195
	196	eb = path->nodes[0];
	197	slot = path->slots[0];
	198	offset = btrfs_item_ptr_offset(eb, slot);
	199	item_size = btrfs_item_size_nr(eb, slot);
	200	if (!IS_ALIGNED(item_size, sizeof(u64))) {
efe120a0	201	btrfs_warn(uuid_root->fs_info, "uuid item with illegal size %lu!",
07b30a49 SB	202	(unsigned long)item_size);
	203	ret = -ENOENT;
	204	goto out;
	205	}
	206	while (item_size) {
	207	__le64 read_subid;
	208
	209	read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid));
	210	if (le64_to_cpu(read_subid) == subid)
	211	break;
	212	offset += sizeof(read_subid);
	213	item_size -= sizeof(read_subid);
	214	}
	215
	216	if (!item_size) {
	217	ret = -ENOENT;
	218	goto out;
	219	}
	220
	221	item_size = btrfs_item_size_nr(eb, slot);
	222	if (item_size == sizeof(subid)) {
	223	ret = btrfs_del_item(trans, uuid_root, path);
	224	goto out;
	225	}
	226
	227	move_dst = offset;
	228	move_src = offset + sizeof(subid);
	229	move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot));
	230	memmove_extent_buffer(eb, move_dst, move_src, move_len);
	231	btrfs_truncate_item(uuid_root, path, item_size - sizeof(subid), 1);
	232
	233	out:
	234	btrfs_free_path(path);
	235	return ret;
	236	}
70f80175 SB	237
	238	static int btrfs_uuid_iter_rem(struct btrfs_root uuid_root, u8 uuid, u8 type,
	239	u64 subid)
	240	{
	241	struct btrfs_trans_handle *trans;
	242	int ret;
	243
	244	/* 1 - for the uuid item */
	245	trans = btrfs_start_transaction(uuid_root, 1);
	246	if (IS_ERR(trans)) {
	247	ret = PTR_ERR(trans);
	248	goto out;
	249	}
	250
	251	ret = btrfs_uuid_tree_rem(trans, uuid_root, uuid, type, subid);
	252	btrfs_end_transaction(trans, uuid_root);
	253
	254	out:
	255	return ret;
	256	}
	257
	258	int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info,
	259	int (check_func)(struct btrfs_fs_info , u8 *, u8,
	260	u64))
	261	{
	262	struct btrfs_root *root = fs_info->uuid_root;
	263	struct btrfs_key key;
70f80175 SB	264	struct btrfs_path *path;
	265	int ret = 0;
	266	struct extent_buffer *leaf;
	267	int slot;
	268	u32 item_size;
	269	unsigned long offset;
	270
	271	path = btrfs_alloc_path();
	272	if (!path) {
	273	ret = -ENOMEM;
	274	goto out;
	275	}
	276
	277	key.objectid = 0;
	278	key.type = 0;
	279	key.offset = 0;
70f80175 SB	280
70f80175 SB	281	again_search_slot:
6174d3cb	282	ret = btrfs_search_forward(root, &key, path, 0);
70f80175 SB	283	if (ret) {
	284	if (ret > 0)
	285	ret = 0;
	286	goto out;
	287	}
	288
	289	while (1) {
	290	cond_resched();
	291	leaf = path->nodes[0];
	292	slot = path->slots[0];
	293	btrfs_item_key_to_cpu(leaf, &key, slot);
	294
	295	if (key.type != BTRFS_UUID_KEY_SUBVOL &&
	296	key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
	297	goto skip;
	298
	299	offset = btrfs_item_ptr_offset(leaf, slot);
	300	item_size = btrfs_item_size_nr(leaf, slot);
	301	if (!IS_ALIGNED(item_size, sizeof(u64))) {
efe120a0	302	btrfs_warn(fs_info, "uuid item with illegal size %lu!",
70f80175 SB	303	(unsigned long)item_size);
	304	goto skip;
	305	}
	306	while (item_size) {
	307	u8 uuid[BTRFS_UUID_SIZE];
	308	__le64 subid_le;
	309	u64 subid_cpu;
	310
	311	put_unaligned_le64(key.objectid, uuid);
	312	put_unaligned_le64(key.offset, uuid + sizeof(u64));
	313	read_extent_buffer(leaf, &subid_le, offset,
	314	sizeof(subid_le));
	315	subid_cpu = le64_to_cpu(subid_le);
	316	ret = check_func(fs_info, uuid, key.type, subid_cpu);
	317	if (ret < 0)
	318	goto out;
	319	if (ret > 0) {
	320	btrfs_release_path(path);
	321	ret = btrfs_uuid_iter_rem(root, uuid, key.type,
	322	subid_cpu);
	323	if (ret == 0) {
	324	/*
	325	* this might look inefficient, but the
	326	* justification is that it is an
	327	* exception that check_func returns 1,
	328	* and that in the regular case only one
	329	* entry per UUID exists.
	330	*/
	331	goto again_search_slot;
	332	}
	333	if (ret < 0 && ret != -ENOENT)
	334	goto out;
	335	}
	336	item_size -= sizeof(subid_le);
	337	offset += sizeof(subid_le);
	338	}
	339
	340	skip:
	341	ret = btrfs_next_item(root, path);
	342	if (ret == 0)
	343	continue;
	344	else if (ret > 0)
	345	ret = 0;
	346	break;
	347	}
	348
	349	out:
	350	btrfs_free_path(path);
	351	if (ret)
efe120a0	352	btrfs_warn(fs_info, "btrfs_uuid_tree_iterate failed %d", ret);
70f80175 SB	353	return 0;
70f80175 SB	354	}