[PATCH v8 04/11] btrfs: delete stripe extent on extent deletion

[Johannes Thumshirn <johannes.thumshirn@wdc.com>]

As each stripe extent is tied to an extent item, delete the stripe extent
once the corresponding extent item is deleted.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 fs/btrfs/extent-tree.c      |  6 +++++
 fs/btrfs/raid-stripe-tree.c | 60 +++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/raid-stripe-tree.h |  2 ++
 3 files changed, 68 insertions(+)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2e11a699ab77..c64dd3fd4463 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2857,6 +2857,12 @@ static int do_free_extent_accounting(struct btrfs_trans_handle *trans,
 			btrfs_abort_transaction(trans, ret);
 			return ret;
 		}
+
+		ret = btrfs_delete_raid_extent(trans, bytenr, num_bytes);
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			return ret;
+		}
 	}
 
 	ret = add_to_free_space_tree(trans, bytenr, num_bytes);
diff --git a/fs/btrfs/raid-stripe-tree.c b/fs/btrfs/raid-stripe-tree.c
index 2415698a8fef..5b12f40877b5 100644
--- a/fs/btrfs/raid-stripe-tree.c
+++ b/fs/btrfs/raid-stripe-tree.c
@@ -15,6 +15,66 @@
 #include "misc.h"
 #include "print-tree.h"
 
+int btrfs_delete_raid_extent(struct btrfs_trans_handle *trans, u64 start,
+			     u64 length)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_root *stripe_root = btrfs_stripe_tree_root(fs_info);
+	struct btrfs_path *path;
+	struct btrfs_key key;
+	struct extent_buffer *leaf;
+	u64 found_start;
+	u64 found_end;
+	u64 end = start + length;
+	int slot;
+	int ret;
+
+	if (!stripe_root)
+		return 0;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	while (1) {
+
+		key.objectid = start;
+		key.type = BTRFS_RAID_STRIPE_KEY;
+		key.offset = length;
+
+		ret = btrfs_search_slot(trans, stripe_root, &key, path, -1, 1);
+		if (ret < 0)
+			break;
+		if (ret > 0) {
+			ret = 0;
+			if (path->slots[0] == 0)
+				break;
+			path->slots[0]--;
+		}
+
+		leaf = path->nodes[0];
+		slot = path->slots[0];
+		btrfs_item_key_to_cpu(leaf, &key, slot);
+		found_start = key.objectid;
+		found_end = found_start + key.offset;
+
+		/* That stripe ends before we start, we're done */
+		if (found_end <= start)
+			break;
+
+		ASSERT(found_start >= start && found_end <= end);
+		ret = btrfs_del_item(trans, stripe_root, path);
+		if (ret)
+			break;
+
+		btrfs_release_path(path);
+	}
+
+	btrfs_free_path(path);
+	return ret;
+
+}
+
 static u8 btrfs_bg_type_to_raid_encoding(u64 map_type)
 {
 	switch (map_type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
diff --git a/fs/btrfs/raid-stripe-tree.h b/fs/btrfs/raid-stripe-tree.h
index f36e4c2d46b0..7560dc501a65 100644
--- a/fs/btrfs/raid-stripe-tree.h
+++ b/fs/btrfs/raid-stripe-tree.h
@@ -11,6 +11,8 @@
 struct btrfs_io_context;
 struct btrfs_io_stripe;
 
+int btrfs_delete_raid_extent(struct btrfs_trans_handle *trans, u64 start,
+			     u64 length);
 int btrfs_insert_raid_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_ordered_extent *ordered_extent);
 

-- 
2.41.0