Retry mounts on -EAGAIN

F2fs may return -EAGAIN on mounting with checkpoint=disable. This
signals that the required garbage collection was taking a while, and
that more garbage collection is required, and will be resumed by
attempting to mount again.

Test: Start device with checkpointing set up with an f2fs userdata
      partition that is in need of heavy garbage collection.
      Mount should fail with EAGAIN and retry
Bug: 122917966

Change-Id: I83341f68e5cffa5f1bd569dfb2037ad5d3cbd7a3

1 files changed, 10 insertions, 2 deletions

diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 943fe109c..d25df77ae 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -556,9 +556,17 @@ static int __mount(const std::string& source, const std::string& target, const F
     mkdir(target.c_str(), 0755);
     errno = 0;
     unsigned long mountflags = entry.flags;
-    int ret = mount(source.c_str(), target.c_str(), entry.fs_type.c_str(), mountflags,
+    int ret = 0;
+    int save_errno = 0;
+    do {
+        if (save_errno == EAGAIN) {
+            PINFO << "Retrying mount (source=" << source << ",target=" << target
+                  << ",type=" << entry.fs_type << ")=" << ret << "(" << save_errno << ")";
+        }
+        ret = mount(source.c_str(), target.c_str(), entry.fs_type.c_str(), mountflags,
                     entry.fs_options.c_str());
-    int save_errno = errno;
+        save_errno = errno;
+    } while (ret && save_errno == EAGAIN);
     const char* target_missing = "";
     const char* source_missing = "";
     if (save_errno == ENOENT) {