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Commit 8775ce01 authored by Daniel Rosenberg's avatar Daniel Rosenberg
Browse files

Support casefolded encryption 

On ext4, enable casefolding if it is requested, but not currently
enabled.

Test: Enable casefolding on device. Check fs configuration on /data
Bug: 138322712
Change-Id: I3d54ab8bf15f28cf52c5b4344aa3fa254af83d60
parent 7cd37ba4

fs_mgr/fs_mgr.cpp

+46 −2
Original line number Diff line number Diff line
@@ -86,6 +86,7 @@ 
#define ZRAM_BACK_DEV   "/sys/block/zram0/backing_dev"



#define SYSFS_EXT4_VERITY "/sys/fs/ext4/features/verity"

#define SYSFS_EXT4_CASEFOLD "/sys/fs/ext4/features/casefold"



// FIXME: this should be in system/extras

#define EXT4_FEATURE_COMPAT_STABLE_INODES 0x0800
@@ -123,6 +124,7 @@ enum FsStatFlags { 
    FS_STAT_SET_RESERVED_BLOCKS_FAILED = 0x20000,

    FS_STAT_ENABLE_ENCRYPTION_FAILED = 0x40000,

    FS_STAT_ENABLE_VERITY_FAILED = 0x80000,

    FS_STAT_ENABLE_CASEFOLD_FAILED = 0x100000,

};



static void log_fs_stat(const std::string& blk_device, int fs_stat) {
@@ -344,6 +346,7 @@ static void tune_quota(const std::string& blk_device, const FstabEntry& entry, 
                       const struct ext4_super_block* sb, int* fs_stat) {

    bool has_quota = (sb->s_feature_ro_compat & cpu_to_le32(EXT4_FEATURE_RO_COMPAT_QUOTA)) != 0;

    bool want_quota = entry.fs_mgr_flags.quota;

    bool want_projid = android::base::GetBoolProperty("ro.emulated_storage.projid", false);



    if (has_quota == want_quota) {

        return;
@@ -360,12 +363,16 @@ static void tune_quota(const std::string& blk_device, const FstabEntry& entry, 
    if (want_quota) {

        LINFO << "Enabling quotas on " << blk_device;

        argv[1] = "-Oquota";

        // Once usr/grp unneeded, make just prjquota to save overhead

        if (want_projid)

            argv[2] = "-Qusrquota,grpquota,prjquota";

        else

            argv[2] = "-Qusrquota,grpquota";

        *fs_stat |= FS_STAT_QUOTA_ENABLED;

    } else {

        LINFO << "Disabling quotas on " << blk_device;

        argv[1] = "-O^quota";

        argv[2] = "-Q^usrquota,^grpquota";

        argv[2] = "-Q^usrquota,^grpquota,^prjquota";

    }



    if (!run_tune2fs(argv, ARRAY_SIZE(argv))) {
@@ -498,6 +505,42 @@ static void tune_verity(const std::string& blk_device, const FstabEntry& entry, 
    }

}



// Enable casefold if needed.

static void tune_casefold(const std::string& blk_device, const struct ext4_super_block* sb,

                          int* fs_stat) {

    bool has_casefold =

            (sb->s_feature_ro_compat & cpu_to_le32(EXT4_FEATURE_INCOMPAT_CASEFOLD)) != 0;

    bool wants_casefold = android::base::GetBoolProperty("ro.emulated_storage.casefold", false);



    if (!wants_casefold || has_casefold) return;



    std::string casefold_support;

    if (!android::base::ReadFileToString(SYSFS_EXT4_CASEFOLD, &casefold_support)) {

        LERROR << "Failed to open " << SYSFS_EXT4_CASEFOLD;

        return;

    }



    if (!(android::base::Trim(casefold_support) == "supported")) {

        LERROR << "Current ext4 casefolding not supported by kernel";

        return;

    }



    if (!tune2fs_available()) {

        LERROR << "Unable to enable ext4 casefold on " << blk_device

               << " because " TUNE2FS_BIN " is missing";

        return;

    }



    LINFO << "Enabling ext4 casefold on " << blk_device;



    const char* argv[] = {TUNE2FS_BIN, "-O", "casefold", "-E", "encoding=utf8", blk_device.c_str()};

    if (!run_tune2fs(argv, ARRAY_SIZE(argv))) {

        LERROR << "Failed to run " TUNE2FS_BIN " to enable "

               << "ext4 casefold on " << blk_device;

        *fs_stat |= FS_STAT_ENABLE_CASEFOLD_FAILED;

    }

}



// Read the primary superblock from an f2fs filesystem.  On failure return

// false.  If it's not an f2fs filesystem, also set FS_STAT_INVALID_MAGIC.

#define F2FS_BLKSIZE 4096
@@ -595,6 +638,7 @@ static int prepare_fs_for_mount(const std::string& blk_device, const FstabEntry& 
            tune_reserved_size(blk_device, entry, &sb, &fs_stat);

            tune_encrypt(blk_device, entry, &sb, &fs_stat);

            tune_verity(blk_device, entry, &sb, &fs_stat);

            tune_casefold(blk_device, &sb, &fs_stat);

        }

    }