daisy: fsync after block device writes

When markBoolSuccessful is invoked, we update the partition table. These writes should be synced before merge operation is resumed post OTA. If not, any crash before these writes are landed to backing storage will lead to incorrect switching of slots. BUG: 175711601 Test: Verify slot switching correctly after crash when merge in progress (on redbull) Signed-off-by: Akilesh Kailash <[email protected]> Change-Id: I4d30342b44aaeb7a4fdc915cc1e53ffb20c17a2f
RevengeOS-Devices · Jul 16, 2021 · 54cb835 · 54cb835
1 parent d304654
commit 54cb835
Showing 1 changed file with 10 additions and 3 deletions.
diff --git a/recovery/gpt-utils/gpt-utils.cpp b/recovery/gpt-utils/gpt-utils.cpp
@@ -156,11 +156,18 @@ static int blk_rw(int fd, int rw, int64_t offset, uint8_t *buf, unsigned len)
     else
         r = read(fd, buf, len);
 
-    if (r < 0)
+    if (r < 0) {
         fprintf(stderr, "block dev %s failed: %s\n", rw ? "write" : "read",
                 strerror(errno));
-    else
-        r = 0;
+    } else {
+        if (rw) {
+            r = fsync(fd);
+            if (r < 0)
+                fprintf(stderr, "fsync failed: %s\n", strerror(errno));
+        } else {
+            r = 0;
+        }
+    }
 
     return r;
 }