From fe52f3946168c858098ad39cc413b4883a36188d Mon Sep 17 00:00:00 2001
From: Yi-Yo Chiang <yochiang@google.com>
Date: Tue, 9 Jan 2024 17:21:35 +0800
Subject: [PATCH] adb-remount-test: Only test mounts that are remounted by us

Right now we assume all RW mounts (minus /data & special FS) are
remounted by us and we apply the remount/overlayfs related checks
on them unconditionally. This would generate false positives when
a partition was RW but not remounted by us.
The test should instead check mounts that were remounted by us
(transitioned from RO to RW after adb-remount), and ignore
partitions that were already RW before running adb-remount.

Bug: 313609600
Test: adb-remount-test
Change-Id: I94e8a35775271f557790a458781657eb3b24a6f5
---
 fs_mgr/tests/adb-remount-test.sh | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/fs_mgr/tests/adb-remount-test.sh b/fs_mgr/tests/adb-remount-test.sh
index c87e564c4..7ac7a1642 100755
--- a/fs_mgr/tests/adb-remount-test.sh
+++ b/fs_mgr/tests/adb-remount-test.sh
@@ -1233,6 +1233,12 @@ adb_sh grep -qE " (/system|/) [^ ]* rw," /proc/mounts </dev/null &&
 adb_sh grep -q " /vendor [^ ]* rw," /proc/mounts </dev/null &&
   die "/vendor is not RO"
 
+data_device=$(adb_sh awk '$2 == "/data" { print $1; exit }' /proc/mounts)
+RO=$(adb_sh grep " ro," /proc/mounts </dev/null |
+    grep -v "^${data_device}" |
+    skip_administrative_mounts |
+    awk '{ print $1 }')
+
 T=$(adb_date)
 adb remount >&2 ||
   die -t "${T}" "adb remount"
@@ -1241,6 +1247,12 @@ adb_sh grep -qE " (/system|/) [^ ]* rw," /proc/mounts </dev/null ||
 adb_sh grep -q " /vendor [^ ]* rw," /proc/mounts </dev/null ||
   die -t "${T}" "/vendor is not RW"
 
+# Only find mounts that are remounted RO -> RW
+RW=$(adb_sh grep " rw," /proc/mounts </dev/null |
+    grep -v "^${data_device}" |
+    skip_administrative_mounts |
+    grep -E "^($(join_with '|' ${RO})) ")
+
 scratch_on_super=false
 if ${overlayfs_needed}; then
   is_overlayfs_mounted /system ||
@@ -1287,27 +1299,19 @@ if ${overlayfs_needed}; then
     fi
   done
 
-  data_device=$(adb_sh awk '$2 == "/data" { print $1; exit }' /proc/mounts)
   # KISS (we do not support sub-mounts for system partitions currently)
   adb_sh grep "^overlay " /proc/mounts </dev/null |
     grep -vE "^overlay.* /(apex|system|vendor)/[^ ]" |
     grep " overlay ro," &&
     die "expected overlay to be RW after remount"
-  adb_sh grep -v noatime /proc/mounts </dev/null |
-    grep -v "^${data_device}" |
-    skip_administrative_mounts |
-    grep -v ' ro,' &&
-    die "mounts are not noatime"
 
-  D=$(adb_sh grep " rw," /proc/mounts </dev/null |
-      grep -v "^${data_device}" |
-      skip_administrative_mounts |
+  D=$(echo "${RW}" |
       awk '{ print $1 }' |
       sed 's|/dev/root|/|' |
       sort -u)
   if [ -n "${D}" ]; then
     adb_sh df -k ${D} </dev/null |
-      sed -e 's/^Filesystem      /Filesystem (rw) /'
+      sed -e 's/^Filesystem     /Filesystem (rw)/'
   fi >&2
   for d in ${D}; do
     if adb_sh tune2fs -l "${d}" </dev/null 2>&1 | grep -q "Filesystem features:.*shared_blocks" ||
@@ -1319,6 +1323,10 @@ else
   is_overlayfs_mounted && die -t "${T}" "unexpected overlay takeover"
 fi
 
+echo -n "${RW}" |
+  grep -v noatime &&
+  die "mounts (rw) are not noatime"
+
 LOG OK "adb remount RW"
 
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