From 3a21e4cf09d85097d0e6531db0f92b386f4d7f6c Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Sat, 28 Jan 2017 01:47:56 +0000 Subject: [PATCH] Btrfs: bulk delete checksum items in the same leaf Very often we have the checksums for an extent spread in multiple items in the checksums tree, and currently the algorithm to delete them starts by looking for them one by one and then deleting them one by one, which is not optimal since each deletion involves shifting all the other items in the leaf and when the leaf reaches some low threshold, to move items off the leaf into its left and right neighbor leafs. Also, after each item deletion we release our search path and start a new search for other checksums items. So optimize this by deleting in bulk all the items in the same leaf that contain checksums for the extent being freed. Signed-off-by: Filipe Manana Reviewed-by: Liu Bo --- fs/btrfs/file-item.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index f7b9a92ad56d1..e35df48b43838 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -643,7 +643,33 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans, /* delete the entire item, it is inside our range */ if (key.offset >= bytenr && csum_end <= end_byte) { - ret = btrfs_del_item(trans, root, path); + int del_nr = 1; + + /* + * Check how many csum items preceding this one in this + * leaf correspond to our range and then delete them all + * at once. + */ + if (key.offset > bytenr && path->slots[0] > 0) { + int slot = path->slots[0] - 1; + + while (slot >= 0) { + struct btrfs_key pk; + + btrfs_item_key_to_cpu(leaf, &pk, slot); + if (pk.offset < bytenr || + pk.type != BTRFS_EXTENT_CSUM_KEY || + pk.objectid != + BTRFS_EXTENT_CSUM_OBJECTID) + break; + path->slots[0] = slot; + del_nr++; + key.offset = pk.offset; + slot--; + } + } + ret = btrfs_del_items(trans, root, path, + path->slots[0], del_nr); if (ret) goto out; if (key.offset == bytenr) -- 2.39.5