return -ENOMEM;
ref->root_id = root_id;
- if (key)
+ if (key) {
ref->key_for_search = *key;
- else
+ /*
+ * We can often find data backrefs with an offset that is too
+ * large (>= LLONG_MAX, maximum allowed file offset) due to
+ * underflows when subtracting a file's offset with the data
+ * offset of its corresponding extent data item. This can
+ * happen for example in the clone ioctl.
+ * So if we detect such case we set the search key's offset to
+ * zero to make sure we will find the matching file extent item
+ * at add_all_parents(), otherwise we will miss it because the
+ * offset taken form the backref is much larger then the offset
+ * of the file extent item. This can make us scan a very large
+ * number of file extent items, but at least it will not make
+ * us miss any.
+ * This is an ugly workaround for a behaviour that should have
+ * never existed, but it does and a fix for the clone ioctl
+ * would touch a lot of places, cause backwards incompatibility
+ * and would not fix the problem for extents cloned with older
+ * kernels.
+ */
+ if (ref->key_for_search.type == BTRFS_EXTENT_DATA_KEY &&
+ ref->key_for_search.offset >= LLONG_MAX)
+ ref->key_for_search.offset = 0;
+ } else {
memset(&ref->key_for_search, 0, sizeof(ref->key_for_search));
+ }
ref->inode_list = NULL;
ref->level = level;
* the first item to check. But sometimes, we may enter it with
* slot==nritems. In that case, go to the next leaf before we continue.
*/
- if (path->slots[0] >= btrfs_header_nritems(path->nodes[0]))
- ret = btrfs_next_old_leaf(root, path, time_seq);
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+ if (time_seq == (u64)-1)
+ ret = btrfs_next_leaf(root, path);
+ else
+ ret = btrfs_next_old_leaf(root, path, time_seq);
+ }
while (!ret && count < total_refs) {
eb = path->nodes[0];
eie = NULL;
}
next:
- ret = btrfs_next_old_item(root, path, time_seq);
+ if (time_seq == (u64)-1)
+ ret = btrfs_next_item(root, path);
+ else
+ ret = btrfs_next_old_item(root, path, time_seq);
}
if (ret > 0)
index = srcu_read_lock(&fs_info->subvol_srcu);
- root = btrfs_read_fs_root_no_name(fs_info, &root_key);
+ root = btrfs_get_fs_root(fs_info, &root_key, false);
if (IS_ERR(root)) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
ret = PTR_ERR(root);
goto out;
}
+ if (btrfs_test_is_dummy_root(root)) {
+ srcu_read_unlock(&fs_info->subvol_srcu, index);
+ ret = -ENOENT;
+ goto out;
+ }
+
if (path->search_commit_root)
root_level = btrfs_header_level(root->commit_root);
+ else if (time_seq == (u64)-1)
+ root_level = btrfs_header_level(root->node);
else
root_level = btrfs_old_root_level(root, time_seq);
}
path->lowest_level = level;
- ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq);
+ if (time_seq == (u64)-1)
+ ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path,
+ 0, 0);
+ else
+ ret = btrfs_search_old_slot(root, &ref->key_for_search, path,
+ time_seq);
/* root node has been locked, we can release @subvol_srcu safely here */
srcu_read_unlock(&fs_info->subvol_srcu, index);
BUG_ON(!ref->wanted_disk_byte);
eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte,
0);
- if (!eb || !extent_buffer_uptodate(eb)) {
+ if (IS_ERR(eb)) {
+ return PTR_ERR(eb);
+ } else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
return -EIO;
}
}
/*
- * merge two lists of backrefs and adjust counts accordingly
+ * merge backrefs and adjust counts accordingly
*
* mode = 1: merge identical keys, if key is set
* FIXME: if we add more keys in __add_prelim_ref, we can merge more here.
ref2 = list_entry(pos2, struct __prelim_ref, list);
+ if (!ref_for_same_block(ref1, ref2))
+ continue;
if (mode == 1) {
- if (!ref_for_same_block(ref1, ref2))
- continue;
if (!ref1->parent && ref2->parent) {
xchg = ref1;
ref1 = ref2;
struct list_head *prefs, u64 *total_refs,
u64 inum)
{
+ struct btrfs_delayed_ref_node *node;
struct btrfs_delayed_extent_op *extent_op = head->extent_op;
- struct rb_node *n = &head->node.rb_node;
struct btrfs_key key;
struct btrfs_key op_key = {0};
int sgn;
btrfs_disk_key_to_cpu(&op_key, &extent_op->key);
spin_lock(&head->lock);
- n = rb_first(&head->ref_root);
- while (n) {
- struct btrfs_delayed_ref_node *node;
- node = rb_entry(n, struct btrfs_delayed_ref_node,
- rb_node);
- n = rb_next(n);
+ list_for_each_entry(node, &head->ref_list, list) {
if (node->seq > seq)
continue;
struct btrfs_delayed_tree_ref *ref;
ref = btrfs_delayed_node_to_tree_ref(node);
- ret = __add_prelim_ref(prefs, ref->root, NULL,
+ ret = __add_prelim_ref(prefs, 0, NULL,
ref->level + 1, ref->parent,
node->bytenr,
node->ref_mod * sgn, GFP_ATOMIC);
struct btrfs_delayed_data_ref *ref;
ref = btrfs_delayed_node_to_data_ref(node);
-
- key.objectid = ref->objectid;
- key.type = BTRFS_EXTENT_DATA_KEY;
- key.offset = ref->offset;
- ret = __add_prelim_ref(prefs, ref->root, &key, 0,
+ ret = __add_prelim_ref(prefs, 0, NULL, 0,
ref->parent, node->bytenr,
node->ref_mod * sgn, GFP_ATOMIC);
break;
*
* NOTE: This can return values > 0
*
+ * If time_seq is set to (u64)-1, it will not search delayed_refs, and behave
+ * much like trans == NULL case, the difference only lies in it will not
+ * commit root.
+ * The special case is for qgroup to search roots in commit_transaction().
+ *
* FIXME some caching might speed things up
*/
static int find_parent_nodes(struct btrfs_trans_handle *trans,
path->skip_locking = 1;
}
+ if (time_seq == (u64)-1)
+ path->skip_locking = 1;
+
/*
* grab both a lock on the path and a lock on the delayed ref head.
* We need both to get a consistent picture of how the refs look
BUG_ON(ret == 0);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
- if (trans && likely(trans->type != __TRANS_DUMMY)) {
+ if (trans && likely(trans->type != __TRANS_DUMMY) &&
+ time_seq != (u64)-1) {
#else
- if (trans) {
+ if (trans && time_seq != (u64)-1) {
#endif
/*
* look if there are updates for this ref queued and lock the
eb = read_tree_block(fs_info->extent_root,
ref->parent, 0);
- if (!eb || !extent_buffer_uptodate(eb)) {
+ if (IS_ERR(eb)) {
+ ret = PTR_ERR(eb);
+ goto out;
+ } else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
ret = -EIO;
goto out;
read_extent_buffer(eb, dest + bytes_left,
name_off, name_len);
if (eb != eb_in) {
- btrfs_tree_read_unlock_blocking(eb);
+ if (!path->skip_locking)
+ btrfs_tree_read_unlock_blocking(eb);
free_extent_buffer(eb);
}
ret = btrfs_find_item(fs_root, path, parent, 0,
eb = path->nodes[0];
/* make sure we can use eb after releasing the path */
if (eb != eb_in) {
- atomic_inc(&eb->refs);
- btrfs_tree_read_lock(eb);
- btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+ if (!path->skip_locking)
+ btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+ path->nodes[0] = NULL;
+ path->locks[0] = 0;
}
btrfs_release_path(path);
iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
int found = 0;
struct extent_buffer *eb;
struct btrfs_inode_extref *extref;
- struct extent_buffer *leaf;
u32 item_size;
u32 cur_offset;
unsigned long ptr;
btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
btrfs_release_path(path);
- leaf = path->nodes[0];
- item_size = btrfs_item_size_nr(leaf, slot);
- ptr = btrfs_item_ptr_offset(leaf, slot);
+ item_size = btrfs_item_size_nr(eb, slot);
+ ptr = btrfs_item_ptr_offset(eb, slot);
cur_offset = 0;
while (cur_offset < item_size) {
if (ret)
break;
- cur_offset += btrfs_inode_extref_name_len(leaf, extref);
+ cur_offset += btrfs_inode_extref_name_len(eb, extref);
cur_offset += sizeof(*extref);
}
btrfs_tree_read_unlock_blocking(eb);
Code Review / kvmfornfv.git / blobdiff