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Commit f8671e0f authored by Yi-Yo Chiang's avatar Yi-Yo Chiang Committed by Yi-yo Chiang
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fs_mgr_fstab: Refactor & cleanup DSU mounting logic 

* Instead of copy-and-modify `/data` mount entry, TransformFstabForDsu()
  can just modify all `/data` mount entries in-place.
* This also stops TransformFstabForDsu() from shuffling the mount entry
  of `/data` in fstab, simplifying the testcase.
* Implement GetEntriesForMountPoint() with GetEntriesByPred().
* Remove unused method BuildDsuUserdataFstabEntry() and
  EraseFstabEntry().

Bug: 235111004
Test: atest CtsFsMgrTestCases
Test: Presubmit GSI boot test
Change-Id: I4afb443b7e527038fb42424543bb1538b01d5ec9
parent fad8eaba

fs_mgr/fs_mgr_fstab.cpp

+16 −66
Original line number Diff line number Diff line
@@ -510,35 +510,6 @@ std::set<std::string> ExtraBootDevices(const Fstab& fstab) { 
    return boot_devices;

}



FstabEntry BuildDsuUserdataFstabEntry() {

    constexpr uint32_t kFlags = MS_NOATIME | MS_NOSUID | MS_NODEV;



    FstabEntry userdata = {

            .blk_device = "userdata_gsi",

            .mount_point = "/data",

            .fs_type = "ext4",

            .flags = kFlags,

            .reserved_size = 128 * 1024 * 1024,

    };

    userdata.fs_mgr_flags.wait = true;

    userdata.fs_mgr_flags.check = true;

    userdata.fs_mgr_flags.logical = true;

    userdata.fs_mgr_flags.quota = true;

    userdata.fs_mgr_flags.late_mount = true;

    userdata.fs_mgr_flags.formattable = true;

    return userdata;

}



bool EraseFstabEntry(Fstab* fstab, const std::string& mount_point) {

    auto iter = std::remove_if(fstab->begin(), fstab->end(),

                               [&](const auto& entry) { return entry.mount_point == mount_point; });

    if (iter != fstab->end()) {

        fstab->erase(iter, fstab->end());

        return true;

    }

    return false;

}



template <typename Pred>

std::vector<FstabEntry*> GetEntriesByPred(Fstab* fstab, const Pred& pred) {

    if (fstab == nullptr) {
@@ -613,34 +584,28 @@ bool ParseFstabFromString(const std::string& fstab_str, bool proc_mounts, Fstab* 
void TransformFstabForDsu(Fstab* fstab, const std::string& dsu_slot,

                          const std::vector<std::string>& dsu_partitions) {

    static constexpr char kDsuKeysDir[] = "/avb";

    // Convert userdata

    // Inherit fstab properties for userdata.

    FstabEntry userdata;

    if (FstabEntry* entry = GetEntryForMountPoint(fstab, "/data")) {

        userdata = *entry;

        userdata.blk_device = android::gsi::kDsuUserdata;

        userdata.fs_mgr_flags.logical = true;

        userdata.fs_mgr_flags.formattable = true;

        if (!userdata.metadata_key_dir.empty()) {

            userdata.metadata_key_dir = android::gsi::GetDsuMetadataKeyDir(dsu_slot);

        }

    } else {

        userdata = BuildDsuUserdataFstabEntry();

    }



    // Convert RO partitions.

    for (auto&& partition : dsu_partitions) {

        if (!EndsWith(partition, gsi::kDsuPostfix)) {

            continue;

        }

        // userdata has been handled

        if (partition == android::gsi::kDsuUserdata) {

            continue;

        }

        // scratch is handled by fs_mgr_overlayfs

        if (partition == android::gsi::kDsuScratch) {

            continue;

        }

        // Convert userdata partition.

        if (partition == android::gsi::kDsuUserdata) {

            for (auto&& entry : GetEntriesForMountPoint(fstab, "/data")) {

                entry->blk_device = android::gsi::kDsuUserdata;

                entry->fs_mgr_flags.logical = true;

                entry->fs_mgr_flags.formattable = true;

                if (!entry->metadata_key_dir.empty()) {

                    entry->metadata_key_dir = android::gsi::GetDsuMetadataKeyDir(dsu_slot);

                }

            }

            continue;

        }

        // Convert RO partitions.

        //

        // dsu_partition_name = corresponding_partition_name + kDsuPostfix

        // e.g.

        //    system_gsi for system
@@ -696,11 +661,6 @@ void TransformFstabForDsu(Fstab* fstab, const std::string& dsu_slot, 
            }

        }

    }



    // Always append userdata last for stable ordering.

    if (EraseFstabEntry(fstab, "/data")) {

        fstab->emplace_back(userdata);

    }

}



void EnableMandatoryFlags(Fstab* fstab) {
@@ -877,18 +837,8 @@ FstabEntry* GetEntryForMountPoint(Fstab* fstab, const std::string& path) { 
}



std::vector<FstabEntry*> GetEntriesForMountPoint(Fstab* fstab, const std::string& path) {

    std::vector<FstabEntry*> entries;

    if (fstab == nullptr) {

        return entries;

    }



    for (auto& entry : *fstab) {

        if (entry.mount_point == path) {

            entries.emplace_back(&entry);

        }

    }



    return entries;

    return GetEntriesByPred(fstab,

                            [&path](const FstabEntry& entry) { return entry.mount_point == path; });

}



std::set<std::string> GetBootDevices() {

fs_mgr/tests/fs_mgr_test.cpp

+8 −8
Original line number Diff line number Diff line
@@ -1127,6 +1127,10 @@ vendor /vendor ext4 ro wait,logical,first_stage_mount 


    auto entry = fstab.begin();



    EXPECT_EQ("/data", entry->mount_point);

    EXPECT_EQ("userdata_gsi", entry->blk_device);

    entry++;



    EXPECT_EQ("/system", entry->mount_point);

    EXPECT_EQ("system_gsi", entry->blk_device);

    EXPECT_EQ("erofs", entry->fs_type);
@@ -1140,10 +1144,6 @@ vendor /vendor ext4 ro wait,logical,first_stage_mount 
    EXPECT_EQ("/vendor", entry->mount_point);

    EXPECT_EQ("vendor", entry->blk_device);

    entry++;



    EXPECT_EQ("/data", entry->mount_point);

    EXPECT_EQ("userdata_gsi", entry->blk_device);

    entry++;

}



TEST(fs_mgr, TransformFstabForDsu_synthesisExt4Entry) {
@@ -1200,6 +1200,10 @@ vendor /vendor ext4 ro wait,logical,first_stage_mount 


    auto entry = fstab.begin();



    EXPECT_EQ("/data", entry->mount_point);

    EXPECT_EQ("userdata_gsi", entry->blk_device);

    entry++;



    EXPECT_EQ("/vendor", entry->mount_point);

    EXPECT_EQ("vendor", entry->blk_device);

    entry++;
@@ -1213,8 +1217,4 @@ vendor /vendor ext4 ro wait,logical,first_stage_mount 
    EXPECT_EQ("system_gsi", entry->blk_device);

    EXPECT_EQ("erofs", entry->fs_type);

    entry++;



    EXPECT_EQ("/data", entry->mount_point);

    EXPECT_EQ("userdata_gsi", entry->blk_device);

    entry++;

}