On Sat, Jan 28, 2017 at 06:06:32AM +0000, [email protected] wrote: > From: Filipe Manana <[email protected]> > > 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.
Looks good. Reviewed-by: Liu Bo <[email protected]> Thanks, -liubo > > Signed-off-by: Filipe Manana <[email protected]> > --- > 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 e97e322..d7d6d4a 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) > -- > 2.7.0.rc3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
