[mirror_ubuntu-artful-kernel.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_fs_info *fs_info, u8 *uuid, u8 type,
			u64 subid_cpu)
{
	struct btrfs_root *uuid_root = fs_info->uuid_root;
	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(fs_info, 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(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_fs_info *fs_info, u8 *uuid, u8 type,
			u64 subid)
{
	struct btrfs_root *uuid_root = fs_info->uuid_root;
	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(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(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(fs_info, 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->fs_info, uuid, type, subid);
	btrfs_end_transaction(trans);

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);
	return ret;
}
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))) {
5d163e0e JM	72	btrfs_warn(uuid_root->fs_info,
	73	"uuid item with illegal size %lu!",
	74	(unsigned long)item_size);
07b30a49 SB	75	goto out;
	76	}
	77	while (item_size) {
	78	__le64 data;
	79
	80	read_extent_buffer(eb, &data, offset, sizeof(data));
	81	if (le64_to_cpu(data) == subid) {
	82	ret = 0;
	83	break;
	84	}
	85	offset += sizeof(data);
	86	item_size -= sizeof(data);
	87	}
	88
	89	out:
	90	btrfs_free_path(path);
	91	return ret;
	92	}
	93
	94	int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans,
6bccf3ab	95	struct btrfs_fs_info fs_info, u8 uuid, u8 type,
07b30a49 SB	96	u64 subid_cpu)
07b30a49 SB	97	{
6bccf3ab	98	struct btrfs_root *uuid_root = fs_info->uuid_root;
07b30a49 SB	99	int ret;
	100	struct btrfs_path *path = NULL;
	101	struct btrfs_key key;
	102	struct extent_buffer *eb;
	103	int slot;
	104	unsigned long offset;
	105	__le64 subid_le;
	106
	107	ret = btrfs_uuid_tree_lookup(uuid_root, uuid, type, subid_cpu);
	108	if (ret != -ENOENT)
	109	return ret;
	110
	111	if (WARN_ON_ONCE(!uuid_root)) {
	112	ret = -EINVAL;
	113	goto out;
	114	}
	115
	116	btrfs_uuid_to_key(uuid, type, &key);
	117
	118	path = btrfs_alloc_path();
	119	if (!path) {
	120	ret = -ENOMEM;
	121	goto out;
	122	}
	123
	124	ret = btrfs_insert_empty_item(trans, uuid_root, path, &key,
	125	sizeof(subid_le));
	126	if (ret >= 0) {
	127	/* Add an item for the type for the first time */
	128	eb = path->nodes[0];
	129	slot = path->slots[0];
	130	offset = btrfs_item_ptr_offset(eb, slot);
	131	} else if (ret == -EEXIST) {
	132	/*
	133	* An item with that type already exists.
	134	* Extend the item and store the new subid at the end.
	135	*/
2ff7e61e	136	btrfs_extend_item(fs_info, path, sizeof(subid_le));
07b30a49 SB	137	eb = path->nodes[0];
	138	slot = path->slots[0];
	139	offset = btrfs_item_ptr_offset(eb, slot);
	140	offset += btrfs_item_size_nr(eb, slot) - sizeof(subid_le);
	141	} else if (ret < 0) {
6bccf3ab	142	btrfs_warn(fs_info,
5d163e0e JM	143	"insert uuid item failed %d (0x%016llx, 0x%016llx) type %u!",
	144	ret, (unsigned long long)key.objectid,
	145	(unsigned long long)key.offset, type);
07b30a49 SB	146	goto out;
	147	}
	148
	149	ret = 0;
	150	subid_le = cpu_to_le64(subid_cpu);
	151	write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le));
	152	btrfs_mark_buffer_dirty(eb);
	153
	154	out:
	155	btrfs_free_path(path);
	156	return ret;
	157	}
	158
	159	int btrfs_uuid_tree_rem(struct btrfs_trans_handle *trans,
6bccf3ab	160	struct btrfs_fs_info fs_info, u8 uuid, u8 type,
07b30a49 SB	161	u64 subid)
07b30a49 SB	162	{
6bccf3ab	163	struct btrfs_root *uuid_root = fs_info->uuid_root;
07b30a49 SB	164	int ret;
	165	struct btrfs_path *path = NULL;
	166	struct btrfs_key key;
	167	struct extent_buffer *eb;
	168	int slot;
	169	unsigned long offset;
	170	u32 item_size;
	171	unsigned long move_dst;
	172	unsigned long move_src;
	173	unsigned long move_len;
	174
	175	if (WARN_ON_ONCE(!uuid_root)) {
	176	ret = -EINVAL;
	177	goto out;
	178	}
	179
	180	btrfs_uuid_to_key(uuid, type, &key);
	181
	182	path = btrfs_alloc_path();
	183	if (!path) {
	184	ret = -ENOMEM;
	185	goto out;
	186	}
	187
	188	ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1);
	189	if (ret < 0) {
0b246afa JM	190	btrfs_warn(fs_info, "error %d while searching for uuid item!",
0b246afa JM	191	ret);
07b30a49 SB	192	goto out;
	193	}
	194	if (ret > 0) {
	195	ret = -ENOENT;
	196	goto out;
	197	}
	198
	199	eb = path->nodes[0];
	200	slot = path->slots[0];
	201	offset = btrfs_item_ptr_offset(eb, slot);
	202	item_size = btrfs_item_size_nr(eb, slot);
	203	if (!IS_ALIGNED(item_size, sizeof(u64))) {
0b246afa	204	btrfs_warn(fs_info, "uuid item with illegal size %lu!",
5d163e0e	205	(unsigned long)item_size);
07b30a49 SB	206	ret = -ENOENT;
	207	goto out;
	208	}
	209	while (item_size) {
	210	__le64 read_subid;
	211
	212	read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid));
	213	if (le64_to_cpu(read_subid) == subid)
	214	break;
	215	offset += sizeof(read_subid);
	216	item_size -= sizeof(read_subid);
	217	}
	218
	219	if (!item_size) {
	220	ret = -ENOENT;
	221	goto out;
	222	}
	223
	224	item_size = btrfs_item_size_nr(eb, slot);
	225	if (item_size == sizeof(subid)) {
	226	ret = btrfs_del_item(trans, uuid_root, path);
	227	goto out;
	228	}
	229
	230	move_dst = offset;
	231	move_src = offset + sizeof(subid);
	232	move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot));
	233	memmove_extent_buffer(eb, move_dst, move_src, move_len);
2ff7e61e	234	btrfs_truncate_item(fs_info, path, item_size - sizeof(subid), 1);
07b30a49 SB	235
	236	out:
	237	btrfs_free_path(path);
	238	return ret;
	239	}
70f80175 SB	240
	241	static int btrfs_uuid_iter_rem(struct btrfs_root uuid_root, u8 uuid, u8 type,
	242	u64 subid)
	243	{
	244	struct btrfs_trans_handle *trans;
	245	int ret;
	246
	247	/* 1 - for the uuid item */
	248	trans = btrfs_start_transaction(uuid_root, 1);
	249	if (IS_ERR(trans)) {
	250	ret = PTR_ERR(trans);
	251	goto out;
	252	}
	253
6bccf3ab	254	ret = btrfs_uuid_tree_rem(trans, uuid_root->fs_info, uuid, type, subid);
3a45bb20	255	btrfs_end_transaction(trans);
70f80175 SB	256
	257	out:
	258	return ret;
	259	}
	260
	261	int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info,
	262	int (check_func)(struct btrfs_fs_info , u8 *, u8,
	263	u64))
	264	{
	265	struct btrfs_root *root = fs_info->uuid_root;
	266	struct btrfs_key key;
70f80175 SB	267	struct btrfs_path *path;
	268	int ret = 0;
	269	struct extent_buffer *leaf;
	270	int slot;
	271	u32 item_size;
	272	unsigned long offset;
	273
	274	path = btrfs_alloc_path();
	275	if (!path) {
	276	ret = -ENOMEM;
	277	goto out;
	278	}
	279
	280	key.objectid = 0;
	281	key.type = 0;
	282	key.offset = 0;
70f80175 SB	283
70f80175 SB	284	again_search_slot:
6174d3cb	285	ret = btrfs_search_forward(root, &key, path, 0);
70f80175 SB	286	if (ret) {
	287	if (ret > 0)
	288	ret = 0;
	289	goto out;
	290	}
	291
	292	while (1) {
	293	cond_resched();
	294	leaf = path->nodes[0];
	295	slot = path->slots[0];
	296	btrfs_item_key_to_cpu(leaf, &key, slot);
	297
	298	if (key.type != BTRFS_UUID_KEY_SUBVOL &&
	299	key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
	300	goto skip;
	301
	302	offset = btrfs_item_ptr_offset(leaf, slot);
	303	item_size = btrfs_item_size_nr(leaf, slot);
	304	if (!IS_ALIGNED(item_size, sizeof(u64))) {
5d163e0e JM	305	btrfs_warn(fs_info,
	306	"uuid item with illegal size %lu!",
	307	(unsigned long)item_size);
70f80175 SB	308	goto skip;
	309	}
	310	while (item_size) {
	311	u8 uuid[BTRFS_UUID_SIZE];
	312	__le64 subid_le;
	313	u64 subid_cpu;
	314
	315	put_unaligned_le64(key.objectid, uuid);
	316	put_unaligned_le64(key.offset, uuid + sizeof(u64));
	317	read_extent_buffer(leaf, &subid_le, offset,
	318	sizeof(subid_le));
	319	subid_cpu = le64_to_cpu(subid_le);
	320	ret = check_func(fs_info, uuid, key.type, subid_cpu);
	321	if (ret < 0)
	322	goto out;
	323	if (ret > 0) {
	324	btrfs_release_path(path);
	325	ret = btrfs_uuid_iter_rem(root, uuid, key.type,
	326	subid_cpu);
	327	if (ret == 0) {
	328	/*
	329	* this might look inefficient, but the
	330	* justification is that it is an
	331	* exception that check_func returns 1,
	332	* and that in the regular case only one
	333	* entry per UUID exists.
	334	*/
	335	goto again_search_slot;
	336	}
	337	if (ret < 0 && ret != -ENOENT)
	338	goto out;
	339	}
	340	item_size -= sizeof(subid_le);
	341	offset += sizeof(subid_le);
	342	}
	343
	344	skip:
	345	ret = btrfs_next_item(root, path);
	346	if (ret == 0)
	347	continue;
	348	else if (ret > 0)
	349	ret = 0;
	350	break;
	351	}
	352
	353	out:
	354	btrfs_free_path(path);
73ba39ab	355	return ret;
70f80175	356	}