From dba750e0e0d0cc996c70d7699cd35e34226565de Mon Sep 17 00:00:00 2001
From: Wei Wang <wvw@google.com>
Date: Wed, 26 Oct 2016 13:35:27 -0700
Subject: [PATCH] Make sure wait for the dm device

Bug: 32408249
Test: on m/s
Change-Id: I65fa4fec94c82ef51d2c8d0aabf9e90b8448f27f
---
 fs_mgr/fs_mgr_verity.cpp | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/fs_mgr/fs_mgr_verity.cpp b/fs_mgr/fs_mgr_verity.cpp
index 767b3b3e8..67104cc3a 100644
--- a/fs_mgr/fs_mgr_verity.cpp
+++ b/fs_mgr/fs_mgr_verity.cpp
@@ -341,6 +341,17 @@ static int resume_verity_table(struct dm_ioctl *io, char *name, int fd)
     return 0;
 }
 
+static int test_access(char *device) {
+    int tries = 25;
+    while (tries--) {
+        if (!access(device, F_OK) || errno != ENOENT) {
+            return 0;
+        }
+        usleep(40 * 1000);
+    }
+    return -1;
+}
+
 static int check_verity_restart(const char *fname)
 {
     char buffer[VERITY_KMSG_BUFSIZE + 1];
@@ -1020,6 +1031,11 @@ loaded:
     fstab->blk_device = verity_blk_name;
     verity_blk_name = 0;
 
+    // make sure we've set everything up properly
+    if (test_access(fstab->blk_device) < 0) {
+        goto out;
+    }
+
     retval = FS_MGR_SETUP_VERITY_SUCCESS;
 
 out: