commit 009f775c535897c61b4040ec0e97823618b7cf91
author Momoko Hattori <momohatt@google.com> Tue Oct 08 14:02:00 2024
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Oct 08 14:02:00 2024
tree d9a0cdac28f2646dd0adf82064e395bd50a79ec3
parent 23f2a038fee82c4149fca20f6842e47f6259d98b

Unmount and drop cache of removable media in ARC before UnmountPath()

This CL implements the logic that asks ARC to drop caches of files in
removable media device when DiskMountManager::UnmountPath() is called
for a removable media mount path. The request to ARC is done via a new
mojo method added in CL:5901557.
Ideally, the rest of the UnmountPath() method should be blocked until
ARC sends the mojo reply after the cache drop operation completion, but
blocking UnmountPath() also causes user-visible delay until the volume
is shown unmounted on the UI. To avoid blocking it for too long, resume
the UnmountPath() method when the mojo reply isn't received after 3
seconds.

BUG=b:317944073
TEST=With http://ag/q/topic:%22avms-drop-caches-all%22:
TEST=* tast run <DUT> crostini.USBShareMassStorage.bookworm_stable
TEST=* Manually check that USB disk unmount on Files app does not hang
       more than 3 seconds even when the ARC-side implementation of
       the new mojo method takes more than 3 seconds to finish

Change-Id: I3b73dac0df2d956c40dd03b05aa103b56e9b2b5c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5845688
Reviewed-by: François Degros <fdegros@chromium.org>
Reviewed-by: Yuichiro Hanada <yhanada@chromium.org>
Commit-Queue: Momoko Hattori <momohatt@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1365529}