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authorChris Mason <chris.mason@oracle.com>2009-03-25 09:55:11 -0400
committerChris Mason <chris.mason@oracle.com>2009-03-25 09:55:11 -0400
commit1a81af4d1d9c60d4313309f937a1fc5567205a87 (patch)
tree535b65b3948d34f0948613afc6ebdfe693683f33 /fs/btrfs/delayed-ref.h
parentaf4176b49c5ee15a9c9b10720c92456b28e7aac7 (diff)
Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_mod
btrfs_update_delayed_ref is optimized to add and remove different references in one pass through the delayed ref tree. It is a zero sum on the total number of refs on a given extent. But, the code was recording an extra ref in the head node. This never made it down to the disk but was used when deciding if it was safe to free the extent while dropping snapshots. The fix used here is to make sure the ref_mod count is unchanged on the head ref when btrfs_update_delayed_ref is called. Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/delayed-ref.h')
-rw-r--r--fs/btrfs/delayed-ref.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index 57153fcc347b..3bec2ff0b15c 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -22,6 +22,7 @@
#define BTRFS_ADD_DELAYED_REF 1 /* add one backref to the tree */
#define BTRFS_DROP_DELAYED_REF 2 /* delete one backref from the tree */
#define BTRFS_ADD_DELAYED_EXTENT 3 /* record a full extent allocation */
+#define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */
struct btrfs_delayed_ref_node {
struct rb_node rb_node;