/*
* xattrs work a lot like directories, this inserts an xattr item
* into the tree
*/
int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, const char *name,
u16 name_len, const void *data, u16 data_len,
u64 dir)
{
int ret = 0;
struct btrfs_path *path;
struct btrfs_dir_item *dir_item;
unsigned long name_ptr, data_ptr;
struct btrfs_key key, location;
struct btrfs_disk_key disk_key;
struct extent_buffer *leaf;
u32 data_size;
key.objectid = dir;
btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
key.offset = btrfs_name_hash(name, name_len);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (name_len + data_len + sizeof(struct btrfs_dir_item) >
BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item))
return -ENOSPC;
data_size = sizeof(*dir_item) + name_len + data_len;
dir_item = insert_with_overflow(trans, root, path, &key, data_size,
name, name_len);
/*
* FIXME: at some point we should handle xattr's that are larger than
* what we can fit in our leaf. We set location to NULL b/c we arent
* pointing at anything else, that will change if we store the xattr
* data in a separate inode.
*/
BUG_ON(IS_ERR(dir_item));
memset(&location, 0, sizeof(location));
leaf = path->nodes[0];
btrfs_cpu_key_to_disk(&disk_key, &location);
btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
btrfs_set_dir_name_len(leaf, dir_item, name_len);
btrfs_set_dir_transid(leaf, dir_item, trans->transid);
btrfs_set_dir_data_len(leaf, dir_item, data_len);
name_ptr = (unsigned long)(dir_item + 1);
data_ptr = (unsigned long)((char *)name_ptr + name_len);
write_extent_buffer(leaf, name, name_ptr, name_len);
write_extent_buffer(leaf, data, data_ptr, data_len);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
return ret;
}
/*
* xattrs work a lot like directories, this inserts an xattr item
* into the tree
*/
int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid,
const char *name, u16 name_len,
const void *data, u16 data_len)
{
int ret = 0;
struct btrfs_dir_item *dir_item;
unsigned long name_ptr, data_ptr;
struct btrfs_key key, location;
struct btrfs_disk_key disk_key;
struct extent_buffer *leaf;
u32 data_size;
if (name_len + data_len > BTRFS_MAX_XATTR_SIZE(root->fs_info))
return -ENOSPC;
key.objectid = objectid;
key.type = BTRFS_XATTR_ITEM_KEY;
key.offset = btrfs_name_hash(name, name_len);
data_size = sizeof(*dir_item) + name_len + data_len;
dir_item = insert_with_overflow(trans, root, path, &key, data_size,
name, name_len);
if (IS_ERR(dir_item))
return PTR_ERR(dir_item);
memset(&location, 0, sizeof(location));
leaf = path->nodes[0];
btrfs_cpu_key_to_disk(&disk_key, &location);
btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
btrfs_set_dir_name_len(leaf, dir_item, name_len);
btrfs_set_dir_transid(leaf, dir_item, trans->transid);
btrfs_set_dir_data_len(leaf, dir_item, data_len);
name_ptr = (unsigned long)(dir_item + 1);
data_ptr = (unsigned long)((char *)name_ptr + name_len);
write_extent_buffer(leaf, name, name_ptr, name_len);
write_extent_buffer(leaf, data, data_ptr, data_len);
btrfs_mark_buffer_dirty(path->nodes[0]);
return ret;
}
/*
* insert a directory item in the tree, doing all the magic for
* both indexes. 'dir' indicates which objectid to insert it into,
* 'location' is the key to stuff into the directory item, 'type' is the
* type of the inode we're pointing to, and 'index' is the sequence number
* to use for the second index (if one is created).
* Will return 0 or -ENOMEM
*/
int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
*root, const char *name, int name_len,
struct inode *dir, struct btrfs_key *location,
u8 type, u64 index)
{
int ret = 0;
int ret2 = 0;
struct btrfs_path *path;
struct btrfs_dir_item *dir_item;
struct extent_buffer *leaf;
unsigned long name_ptr;
struct btrfs_key key;
struct btrfs_disk_key disk_key;
u32 data_size;
key.objectid = btrfs_ino(dir);
btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
key.offset = btrfs_name_hash(name, name_len);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
btrfs_cpu_key_to_disk(&disk_key, location);
data_size = sizeof(*dir_item) + name_len;
dir_item = insert_with_overflow(trans, root, path, &key, data_size,
name, name_len);
if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
if (ret == -EEXIST)
goto second_insert;
goto out_free;
}
leaf = path->nodes[0];
btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
btrfs_set_dir_type(leaf, dir_item, type);
btrfs_set_dir_data_len(leaf, dir_item, 0);
btrfs_set_dir_name_len(leaf, dir_item, name_len);
btrfs_set_dir_transid(leaf, dir_item, trans->transid);
name_ptr = (unsigned long)(dir_item + 1);
write_extent_buffer(leaf, name, name_ptr, name_len);
btrfs_mark_buffer_dirty(leaf);
second_insert:
/* FIXME, use some real flag for selecting the extra index */
if (root == root->fs_info->tree_root) {
ret = 0;
goto out_free;
}
btrfs_release_path(path);
ret2 = btrfs_insert_delayed_dir_index(trans, root, name, name_len, dir,
&disk_key, type, index);
out_free:
btrfs_free_path(path);
if (ret)
return ret;
if (ret2)
return ret2;
return 0;
}
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.
*/
}
