Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1aab3909 authored by David Anderson's avatar David Anderson
Browse files

liblp: Try to merge extents during partition resizes. 

When adding extents to partitions, if the previous extent and new extent
are contiguous, merge them together to avoid allocating unnecessary
device-mapper targets.

Bug: 79173901
Test: liblp_test gtest
Change-Id: I80087df9aea8141c5e16f8d4cdb3dd7da02aee8c
parent 615745ce

fs_mgr/liblp/builder.cpp

+13 −0
Original line number Diff line number Diff line
@@ -84,6 +84,19 @@ Partition::Partition(const std::string& name, const std::string& guid, uint32_t 


void Partition::AddExtent(std::unique_ptr<Extent>&& extent) {

    size_ += extent->num_sectors() * LP_SECTOR_SIZE;



    if (LinearExtent* new_extent = extent->AsLinearExtent()) {

        if (!extents_.empty() && extents_.back()->AsLinearExtent() &&

            extents_.back()->AsLinearExtent()->end_sector() == new_extent->physical_sector()) {

            // If the previous extent can be merged into this new one, do so

            // to avoid creating unnecessary extents.

            LinearExtent* prev_extent = extents_.back()->AsLinearExtent();

            extent = std::make_unique<LinearExtent>(

                    prev_extent->num_sectors() + new_extent->num_sectors(),

                    prev_extent->physical_sector());

            extents_.pop_back();

        }

    }

    extents_.push_back(std::move(extent));

}

fs_mgr/liblp/builder_test.cpp

+5 −0
Original line number Diff line number Diff line
@@ -69,6 +69,11 @@ TEST(liblp, ResizePartition) { 
    EXPECT_EQ(system->size(), 131072);

    EXPECT_EQ(system->extents().size(), 1);

    EXPECT_EQ(system->extents()[0]->num_sectors(), 131072 / LP_SECTOR_SIZE);

    // Test resizing again, that the extents are merged together.

    builder->ResizePartition(system, 1024 * 256);

    EXPECT_EQ(system->size(), 1024 * 256);

    EXPECT_EQ(system->extents().size(), 1);

    EXPECT_EQ(system->extents()[0]->num_sectors(), (1024 * 256) / LP_SECTOR_SIZE);



    // Test shrinking within the same extent.

    builder->ResizePartition(system, 32768);

fs_mgr/liblp/include/liblp/builder.h

+1 −0
Original line number Diff line number Diff line
@@ -81,6 +81,7 @@ class LinearExtent final : public Extent { 
    LinearExtent* AsLinearExtent() override { return this; }



    uint64_t physical_sector() const { return physical_sector_; }

    uint64_t end_sector() const { return physical_sector_ + num_sectors_; }



  private:

    uint64_t physical_sector_;