commit c5ced1e8e31614283d5a77fa43b4c37c87a0c221
author Junichi Uekawa <uekawa@google.com> Wed Sep 16 18:12:35 2020 +0900
committer Junichi Uekawa <uekawa@google.com> Fri Sep 18 09:31:19 2020 +0900
tree 98b695789c78b8af03c940b241528ccff7f1d255
parent dfc059da55983a124a9b7fbb8daf44ad159b1112

apexd: Allow mounting on squashfs.

O_DIRECT does not work on squashfs file systems, and will return EINVAL. Try
without O_DIRECT.

On boards with `BOARD_SYSTEMIMAGE_FILE_SYSTEM_TYPE := squashfs` apexd will fail
to loop mount.  Unfortunately O_DIRECT is not possible because image is
compressed on disk and we do need the buffering.

Bug: 167309455
Bug: 168746790
Test: tast run kukui-arc-r arc.Boot.vm
Change-Id: I9da1af535cb18cebed751ecab0e250780e2df377

apexd/apexd_loop.cpp

diff --git a/apexd/apexd_loop.cpp b/apexd/apexd_loop.cpp
index d97ab34..aaeeaff 100644
--- a/apexd/apexd_loop.cpp
+++ b/apexd/apexd_loop.cpp
@@ -172,10 +172,11 @@
   if (target_fd.get() == -1) {
     struct statfs stbuf;
     int saved_errno = errno;
-    // let's give another try with buffered I/O for EROFS
+    // let's give another try with buffered I/O for EROFS and squashfs
     if (statfs(target.c_str(), &stbuf) != 0 ||
-        stbuf.f_type != EROFS_SUPER_MAGIC_V1) {
-        return Error(saved_errno) << "Failed to open " << target;
+        (stbuf.f_type != EROFS_SUPER_MAGIC_V1 &&
+         stbuf.f_type != SQUASHFS_MAGIC)) {
+      return Error(saved_errno) << "Failed to open " << target;
     }
     LOG(WARNING) << "Fallback to buffered I/O for " << target;
     target_fd.reset(open(target.c_str(), O_RDONLY | O_CLOEXEC));