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

Commit 8471f92a authored by Mark Salyzyn's avatar Mark Salyzyn
Browse files

fs_mgr: overlayfs: ReadFstabFromFile touches errno 

(cherry picked from commit 98a0128e)

Regression from commit 77c28476
("Remove the mount points defined in skip_mount.cfg from
ReadDefaultFstab()") resulted in ReadFstabFromFile to report
errno ENOENT even upon success, preventing clear error propagation
for real failures (ReadFstabFromFile would _always_ report ENOENT).

The bad error propagation resulted in an adb remount failure.

Added immunization against future adjustments that may also
result in a similar regression in adb remount behaviors.

Test: adb-remount-test.sh
Bug: 132594161
Bug: 128961335
Change-Id: Icf5d48bbfc6d938d4b9657ca8004a6a6ddaab5a6
parent 122bf2ae

fs_mgr/fs_mgr_fstab.cpp

+2 −0
Original line number Diff line number Diff line
@@ -704,7 +704,9 @@ bool SkipMountingPartitions(Fstab* fstab) { 
    constexpr const char kSkipMountConfig[] = "/system/etc/init/config/skip_mount.cfg";



    std::string skip_config;

    auto save_errno = errno;

    if (!ReadFileToString(kSkipMountConfig, &skip_config)) {

        errno = save_errno;  // missing file is expected

        return true;

    }

fs_mgr/fs_mgr_overlayfs.cpp

+7 −1
Original line number Diff line number Diff line
@@ -139,7 +139,11 @@ bool fs_mgr_filesystem_has_space(const std::string& mount_point) { 
    // If we have access issues to find out space remaining, return true

    // to prevent us trying to override with overlayfs.

    struct statvfs vst;

    if (statvfs(mount_point.c_str(), &vst)) return true;

    auto save_errno = errno;

    if (statvfs(mount_point.c_str(), &vst)) {

        errno = save_errno;

        return true;

    }



    static constexpr int kPercentThreshold = 1;  // 1%
@@ -265,9 +269,11 @@ bool fs_mgr_rw_access(const std::string& path) { 


bool fs_mgr_overlayfs_already_mounted(const std::string& mount_point, bool overlay_only = true) {

    Fstab fstab;

    auto save_errno = errno;

    if (!ReadFstabFromFile("/proc/mounts", &fstab)) {

        return false;

    }

    errno = save_errno;

    const auto lowerdir = kLowerdirOption + mount_point;

    for (const auto& entry : fstab) {

        if (overlay_only && "overlay" != entry.fs_type && "overlayfs" != entry.fs_type) continue;