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-rw-r--r--fs/btrfs/delayed-ref.h62
1 files changed, 18 insertions, 44 deletions
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index 413927f..0d7c90c 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -139,26 +139,6 @@ struct btrfs_delayed_ref_root {
int flushing;
u64 run_delayed_start;
-
- /*
- * seq number of delayed refs. We need to know if a backref was being
- * added before the currently processed ref or afterwards.
- */
- u64 seq;
-
- /*
- * seq_list holds a list of all seq numbers that are currently being
- * added to the list. While walking backrefs (btrfs_find_all_roots,
- * qgroups), which might take some time, no newer ref must be processed,
- * as it might influence the outcome of the walk.
- */
- struct list_head seq_head;
-
- /*
- * when the only refs we have in the list must not be processed, we want
- * to wait for more refs to show up or for the end of backref walking.
- */
- wait_queue_head_t seq_wait;
};
static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
@@ -195,34 +175,28 @@ int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
struct list_head *cluster, u64 search_start);
-static inline u64 inc_delayed_seq(struct btrfs_delayed_ref_root *delayed_refs)
-{
- assert_spin_locked(&delayed_refs->lock);
- ++delayed_refs->seq;
- return delayed_refs->seq;
-}
+int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
+ struct btrfs_delayed_ref_root *delayed_refs,
+ u64 seq);
-static inline void
-btrfs_get_delayed_seq(struct btrfs_delayed_ref_root *delayed_refs,
- struct seq_list *elem)
+/*
+ * delayed refs with a ref_seq > 0 must be held back during backref walking.
+ * this only applies to items in one of the fs-trees. for_cow items never need
+ * to be held back, so they won't get a ref_seq number.
+ */
+static inline int need_ref_seq(int for_cow, u64 rootid)
{
- assert_spin_locked(&delayed_refs->lock);
- elem->seq = delayed_refs->seq;
- list_add_tail(&elem->list, &delayed_refs->seq_head);
-}
+ if (for_cow)
+ return 0;
-static inline void
-btrfs_put_delayed_seq(struct btrfs_delayed_ref_root *delayed_refs,
- struct seq_list *elem)
-{
- spin_lock(&delayed_refs->lock);
- list_del(&elem->list);
- wake_up(&delayed_refs->seq_wait);
- spin_unlock(&delayed_refs->lock);
-}
+ if (rootid == BTRFS_FS_TREE_OBJECTID)
+ return 1;
-int btrfs_check_delayed_seq(struct btrfs_delayed_ref_root *delayed_refs,
- u64 seq);
+ if ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID)
+ return 1;
+
+ return 0;
+}
/*
* a node might live in a head or a regular ref, this lets you
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