IdleMaint: skip swap space, bind mounts, and virtual filesystems

When the idle maintenance task runs on Cuttlefish, there are several
warnings printed to logcat after the expected messages:

    D vold    : Starting trim of /data
    I vold    : Trimmed 0 bytes on /data in 36ms
    D vold    : Starting trim of /cache
    I vold    : Trimmed 58662912 bytes on /cache in 0ms
    D vold    : Starting trim of /metadata
    I vold    : Trimmed 7725056 bytes on /metadata in 12ms
    D vold    : Starting trim of none
    W vold    : Failed to open none: No such file or directory
    D vold    : Starting trim of /sdcard
    W vold    : Failed to open /sdcard: Not a directory
    D vold    : Starting trim of /mnt/vendor/shared
    W vold    : Trim failed on /mnt/vendor/shared: Inappropriate ioctl for device

This is because vold gathers the filesystems to trim from the fstab, but
it fails to exclude some entries that aren't appropriate to trim:

    /dev/block/zram0 none swap defaults zramsize=75%
    /tmp /sdcard none defaults,bind recoveryonly
    shared /mnt/vendor/shared virtiofs nosuid,nodev,noatime nofail

These should be excluded because they are swap space, a bind mount, and
a virtual filesystem respectively.

Fix addFromFstab() to exclude the above cases.

Afterwards, the messages on Cuttlefish are:

    D vold    : Starting trim of /data
    I vold    : Trimmed 0 bytes on /data in 39ms
    D vold    : Starting trim of /cache
    I vold    : Trimmed 58662912 bytes on /cache in 0ms
    D vold    : Starting trim of /metadata
    I vold    : Trimmed 9822208 bytes on /metadata in 12ms

Change-Id: Idc575106fe6f81c737f684429d58dba4bd5478ad
This commit is contained in:
Eric Biggers 2020-10-15 16:54:38 -07:00
parent 019d5163cc
commit 9a3dc8c709

View file

@ -105,12 +105,16 @@ static void addFromVolumeManager(std::list<std::string>* paths, PathTypes path_t
static void addFromFstab(std::list<std::string>* paths, PathTypes path_type) { static void addFromFstab(std::list<std::string>* paths, PathTypes path_type) {
std::string previous_mount_point; std::string previous_mount_point;
for (const auto& entry : fstab_default) { for (const auto& entry : fstab_default) {
// Skip raw partitions. // Skip raw partitions and swap space.
if (entry.fs_type == "emmc" || entry.fs_type == "mtd") { if (entry.fs_type == "emmc" || entry.fs_type == "mtd" || entry.fs_type == "swap") {
continue; continue;
} }
// Skip read-only filesystems // Skip read-only filesystems and bind mounts.
if (entry.flags & MS_RDONLY) { if (entry.flags & (MS_RDONLY | MS_BIND)) {
continue;
}
// Skip anything without an underlying block device, e.g. virtiofs.
if (entry.blk_device[0] != '/') {
continue; continue;
} }
if (entry.fs_mgr_flags.vold_managed) { if (entry.fs_mgr_flags.vold_managed) {