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

Commit 4cd9a469 authored by Sandeep Patil's avatar Sandeep Patil
Browse files

fs_mgr: refactor: consolidate device tree file reading in one place 



If Device tree values are read for comparison, they produce false
negatives with std::strings due to trailing '\0'. This change
consolidates the triming of trailing null into a single helper function
to be used everywhere fs_mgr reads DT values for comparison or other
reasons where it wishes to have the trailing null trimmed.

b/27805372

Test: Boot sailfish w/ early mount /vendor

Change-Id: If71efc830dc440323df764c7461867e71ed6515b
Signed-off-by: default avatarSandeep Patil <sspatil@google.com>
parent e396c607

fs_mgr/fs_mgr_fstab.cpp

+26 −22
Original line number Diff line number Diff line
@@ -135,6 +135,24 @@ static uint64_t parse_size(const char *arg) 
    return size;

}



/* fills 'dt_value' with the underlying device tree value string without

 * the trailing '\0'. Returns true if 'dt_value' has a valid string, 'false'

 * otherwise.

 */

static bool read_dt_file(const std::string& file_name, std::string* dt_value)

{

    if (android::base::ReadFileToString(file_name, dt_value)) {

        if (!dt_value->empty()) {

            // trim the trailing '\0' out, otherwise the comparison

            // will produce false-negatives.

            dt_value->resize(dt_value->size() - 1);

            return true;

        }

    }



    return false;

}



static int parse_flags(char *flags, struct flag_list *fl,

                       struct fs_mgr_flag_values *flag_vals,

                       char *fs_options, int fs_options_len)
@@ -298,11 +316,7 @@ static int parse_flags(char *flags, struct flag_list *fl, 
static bool is_dt_fstab_compatible() {

    std::string dt_value;

    std::string file_name = kAndroidDtDir + "/fstab/compatible";



    if (android::base::ReadFileToString(file_name, &dt_value)) {

        // trim the trailing '\0' out, otherwise the comparison

        // will produce false-negatives.

        dt_value.resize(dt_value.size() - 1);

    if (read_dt_file(file_name, &dt_value)) {

        if (dt_value == "android,fstab") {

            return true;

        }
@@ -339,41 +353,36 @@ static std::string read_fstab_from_dt() { 
        std::string file_name;

        std::string value;

        file_name = android::base::StringPrintf("%s/%s/dev", fstabdir_name.c_str(), dp->d_name);

        if (!android::base::ReadFileToString(file_name, &value)) {

        if (!read_dt_file(file_name, &value)) {

            LERROR << "dt_fstab: Failed to find device for partition " << dp->d_name;

            fstab.clear();

            break;

        }

        // trim the terminating '\0' out

        value.resize(value.size() - 1);

        fstab_entry.push_back(value);

        fstab_entry.push_back(android::base::StringPrintf("/%s", dp->d_name));



        file_name = android::base::StringPrintf("%s/%s/type", fstabdir_name.c_str(), dp->d_name);

        if (!android::base::ReadFileToString(file_name, &value)) {

        if (!read_dt_file(file_name, &value)) {

            LERROR << "dt_fstab: Failed to find type for partition " << dp->d_name;

            fstab.clear();

            break;

        }

        value.resize(value.size() - 1);

        fstab_entry.push_back(value);



        file_name = android::base::StringPrintf("%s/%s/mnt_flags", fstabdir_name.c_str(), dp->d_name);

        if (!android::base::ReadFileToString(file_name, &value)) {

        if (!read_dt_file(file_name, &value)) {

            LERROR << "dt_fstab: Failed to find type for partition " << dp->d_name;

            fstab.clear();

            break;

        }

        value.resize(value.size() - 1);

        fstab_entry.push_back(value);



        file_name = android::base::StringPrintf("%s/%s/fsmgr_flags", fstabdir_name.c_str(), dp->d_name);

        if (!android::base::ReadFileToString(file_name, &value)) {

        if (!read_dt_file(file_name, &value)) {

            LERROR << "dt_fstab: Failed to find type for partition " << dp->d_name;

            fstab.clear();

            break;

        }

        value.resize(value.size() - 1);

        fstab_entry.push_back(value);



        fstab += android::base::Join(fstab_entry, " ");
@@ -386,16 +395,11 @@ static std::string read_fstab_from_dt() { 
bool is_dt_compatible() {

    std::string file_name = kAndroidDtDir + "/compatible";

    std::string dt_value;

    if (android::base::ReadFileToString(file_name, &dt_value)) {

        if (!dt_value.empty()) {

            // trim the trailing '\0' out, otherwise the comparison

            // will produce false-negatives.

            dt_value.resize(dt_value.size() - 1);

    if (read_dt_file(file_name, &dt_value)) {

        if (dt_value == "android,firmware") {

            return true;

        }

    }

    }



    return false;

}