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btrfs: delayed-ref: Cleanup the unneeded functions.
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Cleanup the rb_tree merge/insert/update functions, since now we use list
instead of rb_tree now.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
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Qu Wenruo authored and Chris Mason committed Jun 10, 2015
1 parent c6fc245 commit c43d160
Showing 1 changed file with 0 additions and 174 deletions.
174 changes: 0 additions & 174 deletions fs/btrfs/delayed-ref.c
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Original file line number Diff line number Diff line change
Expand Up @@ -84,87 +84,6 @@ static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
return 0;
}

/*
* entries in the rb tree are ordered by the byte number of the extent,
* type of the delayed backrefs and content of delayed backrefs.
*/
static int comp_entry(struct btrfs_delayed_ref_node *ref2,
struct btrfs_delayed_ref_node *ref1,
bool compare_seq)
{
if (ref1->bytenr < ref2->bytenr)
return -1;
if (ref1->bytenr > ref2->bytenr)
return 1;
if (ref1->is_head && ref2->is_head)
return 0;
if (ref2->is_head)
return -1;
if (ref1->is_head)
return 1;
if (ref1->type < ref2->type)
return -1;
if (ref1->type > ref2->type)
return 1;
if (ref1->no_quota > ref2->no_quota)
return 1;
if (ref1->no_quota < ref2->no_quota)
return -1;
/* merging of sequenced refs is not allowed */
if (compare_seq) {
if (ref1->seq < ref2->seq)
return -1;
if (ref1->seq > ref2->seq)
return 1;
}
if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) {
return comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref2),
btrfs_delayed_node_to_tree_ref(ref1),
ref1->type);
} else if (ref1->type == BTRFS_EXTENT_DATA_REF_KEY ||
ref1->type == BTRFS_SHARED_DATA_REF_KEY) {
return comp_data_refs(btrfs_delayed_node_to_data_ref(ref2),
btrfs_delayed_node_to_data_ref(ref1));
}
BUG();
return 0;
}

/*
* insert a new ref into the rbtree. This returns any existing refs
* for the same (bytenr,parent) tuple, or NULL if the new node was properly
* inserted.
*/
static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
struct rb_node *node)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent_node = NULL;
struct btrfs_delayed_ref_node *entry;
struct btrfs_delayed_ref_node *ins;
int cmp;

ins = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
while (*p) {
parent_node = *p;
entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
rb_node);

cmp = comp_entry(entry, ins, 1);
if (cmp < 0)
p = &(*p)->rb_left;
else if (cmp > 0)
p = &(*p)->rb_right;
else
return entry;
}

rb_link_node(node, parent_node, p);
rb_insert_color(node, root);
return NULL;
}

/* insert a new ref to head ref rbtree */
static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
struct rb_node *node)
Expand Down Expand Up @@ -277,57 +196,6 @@ static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
trans->delayed_ref_updates--;
}

static int merge_ref(struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_root *delayed_refs,
struct btrfs_delayed_ref_head *head,
struct btrfs_delayed_ref_node *ref, u64 seq)
{
struct rb_node *node;
int mod = 0;
int done = 0;

node = rb_next(&ref->rb_node);
while (!done && node) {
struct btrfs_delayed_ref_node *next;

next = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
node = rb_next(node);
if (seq && next->seq >= seq)
break;
if (comp_entry(ref, next, 0))
continue;

if (ref->action == next->action) {
mod = next->ref_mod;
} else {
if (ref->ref_mod < next->ref_mod) {
struct btrfs_delayed_ref_node *tmp;

tmp = ref;
ref = next;
next = tmp;
done = 1;
}
mod = -next->ref_mod;
}

drop_delayed_ref(trans, delayed_refs, head, next);
ref->ref_mod += mod;
if (ref->ref_mod == 0) {
drop_delayed_ref(trans, delayed_refs, head, ref);
done = 1;
} else {
/*
* You can't have multiples of the same ref on a tree
* block.
*/
WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
}
}
return done;
}

int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
struct btrfs_delayed_ref_root *delayed_refs,
u64 seq)
Expand Down Expand Up @@ -400,48 +268,6 @@ btrfs_select_ref_head(struct btrfs_trans_handle *trans)
return head;
}

/*
* helper function to update an extent delayed ref in the
* rbtree. existing and update must both have the same
* bytenr and parent
*
* This may free existing if the update cancels out whatever
* operation it was doing.
*/
static noinline void
update_existing_ref(struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_root *delayed_refs,
struct btrfs_delayed_ref_head *head,
struct btrfs_delayed_ref_node *existing,
struct btrfs_delayed_ref_node *update)
{
if (update->action != existing->action) {
/*
* this is effectively undoing either an add or a
* drop. We decrement the ref_mod, and if it goes
* down to zero we just delete the entry without
* every changing the extent allocation tree.
*/
existing->ref_mod--;
if (existing->ref_mod == 0)
drop_delayed_ref(trans, delayed_refs, head, existing);
else
WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
} else {
WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
/*
* the action on the existing ref matches
* the action on the ref we're trying to add.
* Bump the ref_mod by one so the backref that
* is eventually added/removed has the correct
* reference count
*/
existing->ref_mod += update->ref_mod;
}
}

/*
* Helper to insert the ref_node to the tail or merge with tail.
*
Expand Down

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