Exemplo n.º 1
0
/*
 * insert a name into a directory, doing overflow properly if there is a hash
 * collision.  data_size indicates how big the item inserted should be.  On
 * success a struct btrfs_dir_item pointer is returned, otherwise it is
 * an ERR_PTR.
 *
 * The name is not copied into the dir item, you have to do that yourself.
 */
static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
						   *trans,
						   struct btrfs_root *root,
						   struct btrfs_path *path,
						   struct btrfs_key *cpu_key,
						   u32 data_size,
						   const char *name,
						   int name_len)
{
	int ret;
	char *ptr;
	struct btrfs_item *item;
	struct extent_buffer *leaf;

	ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
	if (ret == -EEXIST) {
		struct btrfs_dir_item *di;
		di = btrfs_match_dir_item_name(root, path, name, name_len);
		if (di)
			return ERR_PTR(-EEXIST);
		btrfs_extend_item(trans, root, path, data_size);
	} else if (ret < 0)
		return ERR_PTR(ret);
	WARN_ON(ret > 0);
	leaf = path->nodes[0];
	item = btrfs_item_nr(leaf, path->slots[0]);
	ptr = btrfs_item_ptr(leaf, path->slots[0], char);
	BUG_ON(data_size > btrfs_item_size(leaf, item));
	ptr += btrfs_item_size(leaf, item) - data_size;
	return (struct btrfs_dir_item *)ptr;
}
Exemplo n.º 2
0
static struct btrfs_dir_item *insert_with_overflow(struct
						   btrfs_trans_handle *trans,
						   struct btrfs_root *root,
						   struct btrfs_path *path,
						   struct btrfs_key *cpu_key,
						   u32 data_size)
{
	int ret;
	char *ptr;
	struct btrfs_item *item;
	struct btrfs_leaf *leaf;

	ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
	if (ret == -EEXIST) {
		ret = btrfs_extend_item(trans, root, path, data_size);
		BUG_ON(ret > 0);
		if (ret)
			return NULL;
	}
	BUG_ON(ret > 0);
	leaf = &path->nodes[0]->leaf;
	item = leaf->items + path->slots[0];
	ptr = btrfs_item_ptr(leaf, path->slots[0], char);
	BUG_ON(data_size > btrfs_item_size(item));
	ptr += btrfs_item_size(item) - data_size;
	return (struct btrfs_dir_item *)ptr;
}
Exemplo n.º 3
0
int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root,
			   const char *name, int name_len,
			   u64 inode_objectid, u64 ref_objectid, u64 index)
{
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_inode_ref *ref;
	unsigned long ptr;
	int ret;
	int ins_len = name_len + sizeof(*ref);

	key.objectid = inode_objectid;
	key.offset = ref_objectid;
	btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	ret = btrfs_insert_empty_item(trans, root, path, &key,
				      ins_len);
	if (ret == -EEXIST) {
		u32 old_size;

		if (find_name_in_backref(path, name, name_len, &ref))
			goto out;

		old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
		ret = btrfs_extend_item(trans, root, path, ins_len);
		BUG_ON(ret);
		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
				     struct btrfs_inode_ref);
		ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
		ptr = (unsigned long)(ref + 1);
		ret = 0;
	} else if (ret < 0) {
Exemplo n.º 4
0
/*
 * insert a name into a directory, doing overflow properly if there is a hash
 * collision.  data_size indicates how big the item inserted should be.  On
 * success a struct btrfs_dir_item pointer is returned, otherwise it is
 * an ERR_PTR.
 *
 * The name is not copied into the dir item, you have to do that yourself.
 */
static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
						   *trans,
						   struct btrfs_root *root,
						   struct btrfs_path *path,
						   struct btrfs_key *cpu_key,
						   u32 data_size,
						   const char *name,
						   int name_len)
{
	int ret;
	char *ptr;
	struct btrfs_item *item;
	struct extent_buffer *leaf;

	ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
	if (ret == -EEXIST) {
		struct btrfs_dir_item *di;
		di = btrfs_match_dir_item_name(root, path, name, name_len);
		if (di)
			return ERR_PTR(-EEXIST);
<<<<<<< HEAD
		btrfs_extend_item(trans, root, path, data_size);
	} else if (ret < 0)
Exemplo n.º 5
0
int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
			  struct btrfs_root *root, u64 alloc_end,
			  u64 bytenr, char *data, size_t len)
{
	int ret;
	struct btrfs_key file_key;
	struct btrfs_key found_key;
	u64 next_offset = (u64)-1;
	int found_next = 0;
	struct btrfs_path *path;
	struct btrfs_csum_item *item;
	struct extent_buffer *leaf = NULL;
	u64 csum_offset;
	u32 csum_result = ~(u32)0;
	u32 nritems;
	u32 ins_size;
	u16 csum_size =
		btrfs_super_csum_size(&root->fs_info->super_copy);

	path = btrfs_alloc_path();
	BUG_ON(!path);

	file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
	file_key.offset = bytenr;
	file_key.type = BTRFS_EXTENT_CSUM_KEY;

	item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
	if (!IS_ERR(item)) {
		leaf = path->nodes[0];
		goto found;
	}
	ret = PTR_ERR(item);
	if (ret == -EFBIG) {
		u32 item_size;
		/* we found one, but it isn't big enough yet */
		leaf = path->nodes[0];
		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
		if ((item_size / csum_size) >= MAX_CSUM_ITEMS(root, csum_size)) {
			/* already at max size, make a new one */
			goto insert;
		}
	} else {
		int slot = path->slots[0] + 1;
		/* we didn't find a csum item, insert one */
		nritems = btrfs_header_nritems(path->nodes[0]);
		if (path->slots[0] >= nritems - 1) {
			ret = btrfs_next_leaf(root, path);
			if (ret == 1)
				found_next = 1;
			if (ret != 0)
				goto insert;
			slot = 0;
		}
		btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
		if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
		    found_key.type != BTRFS_EXTENT_CSUM_KEY) {
			found_next = 1;
			goto insert;
		}
		next_offset = found_key.offset;
		found_next = 1;
		goto insert;
	}

	/*
	 * at this point, we know the tree has an item, but it isn't big
	 * enough yet to put our csum in.  Grow it
	 */
	btrfs_release_path(root, path);
	ret = btrfs_search_slot(trans, root, &file_key, path,
				csum_size, 1);
	if (ret < 0)
		goto fail;
	if (ret == 0) {
		BUG();
	}
	if (path->slots[0] == 0) {
		goto insert;
	}
	path->slots[0]--;
	leaf = path->nodes[0];
	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	csum_offset = (file_key.offset - found_key.offset) / root->sectorsize;
	if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
	    found_key.type != BTRFS_EXTENT_CSUM_KEY ||
	    csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
		goto insert;
	}
	if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
	    csum_size) {
		u32 diff = (csum_offset + 1) * csum_size;
		diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
		if (diff != csum_size)
			goto insert;
		ret = btrfs_extend_item(trans, root, path, diff);
		BUG_ON(ret);
		goto csum;
	}

insert:
	btrfs_release_path(root, path);
	csum_offset = 0;
	if (found_next) {
		u64 tmp = min(alloc_end, next_offset);
		tmp -= file_key.offset;
		tmp /= root->sectorsize;
		tmp = max((u64)1, tmp);
		tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
		ins_size = csum_size * tmp;
	} else {
		ins_size = csum_size;
	}
	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
				      ins_size);
	if (ret < 0)
		goto fail;
	if (ret != 0) {
		WARN_ON(1);
		goto fail;
	}
csum:
	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
	ret = 0;
	item = (struct btrfs_csum_item *)((unsigned char *)item +
					  csum_offset * csum_size);
found:
	csum_result = btrfs_csum_data(root, data, csum_result, len);
	btrfs_csum_final(csum_result, (char *)&csum_result);
	if (csum_result == 0) {
		printk("csum result is 0 for block %llu\n",
		       (unsigned long long)bytenr);
	}

	write_extent_buffer(leaf, &csum_result, (unsigned long)item,
			    csum_size);
	btrfs_mark_buffer_dirty(path->nodes[0]);
fail:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	return ret;
}
Exemplo n.º 6
0
Arquivo: xattr.c Projeto: 020gzh/linux
static int do_setxattr(struct btrfs_trans_handle *trans,
		       struct inode *inode, const char *name,
		       const void *value, size_t size, int flags)
{
	struct btrfs_dir_item *di = NULL;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_path *path;
	size_t name_len = strlen(name);
	int ret = 0;

	if (name_len + size > BTRFS_MAX_XATTR_SIZE(root))
		return -ENOSPC;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
	path->skip_release_on_error = 1;

	if (!value) {
		di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
					name, name_len, -1);
		if (!di && (flags & XATTR_REPLACE))
			ret = -ENODATA;
		else if (IS_ERR(di))
			ret = PTR_ERR(di);
		else if (di)
			ret = btrfs_delete_one_dir_name(trans, root, path, di);
		goto out;
	}

	/*
	 * For a replace we can't just do the insert blindly.
	 * Do a lookup first (read-only btrfs_search_slot), and return if xattr
	 * doesn't exist. If it exists, fall down below to the insert/replace
	 * path - we can't race with a concurrent xattr delete, because the VFS
	 * locks the inode's i_mutex before calling setxattr or removexattr.
	 */
	if (flags & XATTR_REPLACE) {
		ASSERT(inode_is_locked(inode));
		di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode),
					name, name_len, 0);
		if (!di)
			ret = -ENODATA;
		else if (IS_ERR(di))
			ret = PTR_ERR(di);
		if (ret)
			goto out;
		btrfs_release_path(path);
		di = NULL;
	}

	ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
				      name, name_len, value, size);
	if (ret == -EOVERFLOW) {
		/*
		 * We have an existing item in a leaf, split_leaf couldn't
		 * expand it. That item might have or not a dir_item that
		 * matches our target xattr, so lets check.
		 */
		ret = 0;
		btrfs_assert_tree_locked(path->nodes[0]);
		di = btrfs_match_dir_item_name(root, path, name, name_len);
		if (!di && !(flags & XATTR_REPLACE)) {
			ret = -ENOSPC;
			goto out;
		}
	} else if (ret == -EEXIST) {
		ret = 0;
		di = btrfs_match_dir_item_name(root, path, name, name_len);
		ASSERT(di); /* logic error */
	} else if (ret) {
		goto out;
	}

	if (di && (flags & XATTR_CREATE)) {
		ret = -EEXIST;
		goto out;
	}

	if (di) {
		/*
		 * We're doing a replace, and it must be atomic, that is, at
		 * any point in time we have either the old or the new xattr
		 * value in the tree. We don't want readers (getxattr and
		 * listxattrs) to miss a value, this is specially important
		 * for ACLs.
		 */
		const int slot = path->slots[0];
		struct extent_buffer *leaf = path->nodes[0];
		const u16 old_data_len = btrfs_dir_data_len(leaf, di);
		const u32 item_size = btrfs_item_size_nr(leaf, slot);
		const u32 data_size = sizeof(*di) + name_len + size;
		struct btrfs_item *item;
		unsigned long data_ptr;
		char *ptr;

		if (size > old_data_len) {
			if (btrfs_leaf_free_space(root, leaf) <
			    (size - old_data_len)) {
				ret = -ENOSPC;
				goto out;
			}
		}

		if (old_data_len + name_len + sizeof(*di) == item_size) {
			/* No other xattrs packed in the same leaf item. */
			if (size > old_data_len)
				btrfs_extend_item(root, path,
						  size - old_data_len);
			else if (size < old_data_len)
				btrfs_truncate_item(root, path, data_size, 1);
		} else {
			/* There are other xattrs packed in the same item. */
			ret = btrfs_delete_one_dir_name(trans, root, path, di);
			if (ret)
				goto out;
			btrfs_extend_item(root, path, data_size);
		}

		item = btrfs_item_nr(slot);
		ptr = btrfs_item_ptr(leaf, slot, char);
		ptr += btrfs_item_size(leaf, item) - data_size;
		di = (struct btrfs_dir_item *)ptr;
		btrfs_set_dir_data_len(leaf, di, size);
		data_ptr = ((unsigned long)(di + 1)) + name_len;
		write_extent_buffer(leaf, value, data_ptr, size);
		btrfs_mark_buffer_dirty(leaf);
	} else {
		/*
		 * Insert, and we had space for the xattr, so path->slots[0] is
		 * where our xattr dir_item is and btrfs_insert_xattr_item()
		 * filled it.
		 */
	}
Exemplo n.º 7
0
int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans, u8 *uuid, u8 type,
			u64 subid_cpu)
{
	struct btrfs_fs_info *fs_info = trans->fs_info;
	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(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 {
		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;
}