Unmount pass_through path last.

There've been reports of issues where, when a volume is ejected, the
MediaProvider process gets killed. This happens because the
MediaProvider has a file open on the volume (eg, during a scan). We do
abort the scan when the volume is ejected, however this could take some
time. So, we give MediaProvider a bit more time before getting killed,
by only looking for files open on the pass_through paths last. This
order anyway seems to make more sense - ideally we kill apps using
external storage before we unmount the pass_through path underlying it.

Bug: 171367622
Test: atets AdoptableHostTest
Change-Id: Ie8eacaa72a80ff8161ecf1e8c0243afcd890ee39

diff --git a/Utils.cpp b/Utils.cpp
index afb0989..d5648f7 100644 (file)
--- a/Utils.cpp
+++ b/Utils.cpp
@@ -1588,18 +1588,8 @@ status_t UnmountUserFuse(userid_t user_id, const std::string& absolute_lower_pat
     std::string pass_through_path(
             StringPrintf("/mnt/pass_through/%d/%s", user_id, relative_upper_path.c_str()));
 
-    // Best effort unmount pass_through path
-    sSleepOnUnmount = false;
-    LOG(INFO) << "Unmounting pass_through_path " << pass_through_path;
-    auto status = ForceUnmount(pass_through_path);
-    if (status != android::OK) {
-        LOG(ERROR) << "Failed to unmount " << pass_through_path;
-    }
-    rmdir(pass_through_path.c_str());
-
     LOG(INFO) << "Unmounting fuse path " << fuse_path;
     android::status_t result = ForceUnmount(fuse_path);
-    sSleepOnUnmount = true;
     if (result != android::OK) {
         // TODO(b/135341433): MNT_DETACH is needed for fuse because umount2 can fail with EBUSY.
         // Figure out why we get EBUSY and remove this special casing if possible.
@@ -1613,6 +1603,13 @@ status_t UnmountUserFuse(userid_t user_id, const std::string& absolute_lower_pat
     }
     rmdir(fuse_path.c_str());
 
+    LOG(INFO) << "Unmounting pass_through_path " << pass_through_path;
+    auto status = ForceUnmount(pass_through_path);
+    if (status != android::OK) {
+        LOG(ERROR) << "Failed to unmount " << pass_through_path;
+    }
+    rmdir(pass_through_path.c_str());
+
     return result;
 }