[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))) {
		pr_warn("btrfs: uuid item with illegal size %lu!\n",
			(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) {
		pr_warn("btrfs: insert uuid item failed %d (0x%016llx, 0x%016llx) type %u!\n",
			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) {
		pr_warn("btrfs: error %d while searching for uuid item!\n",
			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))) {
		pr_warn("btrfs: uuid item with illegal size %lu!\n",
			(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_key max_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;
	max_key.objectid = (u64)-1;
	max_key.type = (u8)-1;
	max_key.offset = (u64)-1;

again_search_slot:
	path->keep_locks = 1;
	ret = btrfs_search_forward(root, &key, &max_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))) {
			pr_warn("btrfs: uuid item with illegal size %lu!\n",
				(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)
		pr_warn("btrfs: btrfs_uuid_tree_iterate failed %d\n", 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))) {
72	pr_warn("btrfs: uuid item with illegal size %lu!\n",
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) {
140	pr_warn("btrfs: insert uuid item failed %d (0x%016llx, 0x%016llx) type %u!\n",
141	ret, (unsigned long long)key.objectid,
142	(unsigned long long)key.offset, type);
143	goto out;
144	}
145
146	ret = 0;
147	subid_le = cpu_to_le64(subid_cpu);
148	write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le));
149	btrfs_mark_buffer_dirty(eb);
150
151	out:
152	btrfs_free_path(path);
153	return ret;
154	}
155
156	int btrfs_uuid_tree_rem(struct btrfs_trans_handle *trans,
157	struct btrfs_root uuid_root, u8 uuid, u8 type,
158	u64 subid)
159	{
160	int ret;
161	struct btrfs_path *path = NULL;
162	struct btrfs_key key;
163	struct extent_buffer *eb;
164	int slot;
165	unsigned long offset;
166	u32 item_size;
167	unsigned long move_dst;
168	unsigned long move_src;
169	unsigned long move_len;
170
171	if (WARN_ON_ONCE(!uuid_root)) {
172	ret = -EINVAL;
173	goto out;
174	}
175
176	btrfs_uuid_to_key(uuid, type, &key);
177
178	path = btrfs_alloc_path();
179	if (!path) {
180	ret = -ENOMEM;
181	goto out;
182	}
183
184	ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1);
185	if (ret < 0) {
186	pr_warn("btrfs: error %d while searching for uuid item!\n",
187	ret);
188	goto out;
189	}
190	if (ret > 0) {
191	ret = -ENOENT;
192	goto out;
193	}
194
195	eb = path->nodes[0];
196	slot = path->slots[0];
197	offset = btrfs_item_ptr_offset(eb, slot);
198	item_size = btrfs_item_size_nr(eb, slot);
199	if (!IS_ALIGNED(item_size, sizeof(u64))) {
200	pr_warn("btrfs: uuid item with illegal size %lu!\n",
201	(unsigned long)item_size);
202	ret = -ENOENT;
203	goto out;
204	}
205	while (item_size) {
206	__le64 read_subid;
207
208	read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid));
209	if (le64_to_cpu(read_subid) == subid)
210	break;
211	offset += sizeof(read_subid);
212	item_size -= sizeof(read_subid);
213	}
214
215	if (!item_size) {
216	ret = -ENOENT;
217	goto out;
218	}
219
220	item_size = btrfs_item_size_nr(eb, slot);
221	if (item_size == sizeof(subid)) {
222	ret = btrfs_del_item(trans, uuid_root, path);
223	goto out;
224	}
225
226	move_dst = offset;
227	move_src = offset + sizeof(subid);
228	move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot));
229	memmove_extent_buffer(eb, move_dst, move_src, move_len);
230	btrfs_truncate_item(uuid_root, path, item_size - sizeof(subid), 1);
231
232	out:
233	btrfs_free_path(path);
234	return ret;
235	}
70f80175 SB	236
	237	static int btrfs_uuid_iter_rem(struct btrfs_root uuid_root, u8 uuid, u8 type,
	238	u64 subid)
	239	{
	240	struct btrfs_trans_handle *trans;
	241	int ret;
	242
	243	/* 1 - for the uuid item */
	244	trans = btrfs_start_transaction(uuid_root, 1);
	245	if (IS_ERR(trans)) {
	246	ret = PTR_ERR(trans);
	247	goto out;
	248	}
	249
	250	ret = btrfs_uuid_tree_rem(trans, uuid_root, uuid, type, subid);
	251	btrfs_end_transaction(trans, uuid_root);
	252
	253	out:
	254	return ret;
	255	}
	256
	257	int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info,
	258	int (check_func)(struct btrfs_fs_info , u8 *, u8,
	259	u64))
	260	{
	261	struct btrfs_root *root = fs_info->uuid_root;
	262	struct btrfs_key key;
	263	struct btrfs_key max_key;
	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;
	280	max_key.objectid = (u64)-1;
	281	max_key.type = (u8)-1;
	282	max_key.offset = (u64)-1;
	283
	284	again_search_slot:
	285	path->keep_locks = 1;
	286	ret = btrfs_search_forward(root, &key, &max_key, path, 0);
	287	if (ret) {
	288	if (ret > 0)
	289	ret = 0;
	290	goto out;
	291	}
	292
	293	while (1) {
	294	cond_resched();
	295	leaf = path->nodes[0];
	296	slot = path->slots[0];
	297	btrfs_item_key_to_cpu(leaf, &key, slot);
	298
	299	if (key.type != BTRFS_UUID_KEY_SUBVOL &&
300	key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
301	goto skip;
302
303	offset = btrfs_item_ptr_offset(leaf, slot);
304	item_size = btrfs_item_size_nr(leaf, slot);
305	if (!IS_ALIGNED(item_size, sizeof(u64))) {
306	pr_warn("btrfs: uuid item with illegal size %lu!\n",
307	(unsigned long)item_size);
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);
355	if (ret)
356	pr_warn("btrfs: btrfs_uuid_tree_iterate failed %d\n", ret);
357	return 0;
358	}