recovery: autodetect filesystem type

* Multiple fstab lines (supported in android) cause recovery to fail
  to mount partitions if the fs type is not the same as the first
  fstab entry. So when we attempt to find an fstab entry that matches
  a path for an f2fs, ext4 or vfat type, check it against blkid's
  determination of what filesystem type it is. If there is a discrepancy,
  query fs_mgr for the next possible entry that matches that path until
  either we find one that is good, or run out of fstab entries.

* Also attempt to autodetect the filesystem type for mounting from
  update.zips.

Change-Id: Ib6f4535dd88ef714ae1ca6fb0ffae1c7dac0f7ce

4 files changed, 42 insertions, 3 deletions

diff --git a/Android.mk b/Android.mk
index 0ae92de..d51e218 100644
--- a/Android.mk
+++ b/Android.mk
@@ -70,6 +70,7 @@ LOCAL_C_INCLUDES += \
     system/vold \
     system/extras/ext4_utils \
     system/core/adb \
+    external/e2fsprogs/lib
 
 LOCAL_STATIC_LIBRARIES := \
     libext4_utils_static \
@@ -221,7 +222,9 @@ LOCAL_STATIC_LIBRARIES += \
     libcutils \
     liblog \
     libm \
-    libc
+    libc \
+    libext2_blkid \
+    libext2_uuid
 
 LOCAL_C_INCLUDES +=         	\
     system/core/fs_mgr/include	\
@@ -232,7 +235,8 @@ LOCAL_C_INCLUDES +=         	\
     external/libtar/listhash    \
     external/openssl/include    \
     external/zlib               \
-    bionic/libc/bionic
+    bionic/libc/bionic          \
+    external/e2fsprogs/lib
 
 
 include $(BUILD_EXECUTABLE)
diff --git a/roots.cpp b/roots.cpp
index d27a2dd..3c51c35 100644
--- a/roots.cpp
+++ b/roots.cpp
@@ -37,6 +37,7 @@ extern "C" {
 }
 
 #include "voldclient.h"
+#include <blkid/blkid.h>
 
 static struct fstab *fstab = NULL;
 
@@ -143,7 +144,27 @@ bool volume_is_verity(Volume *v)
 }
 
 Volume* volume_for_path(const char* path) {
-    return fs_mgr_get_entry_for_mount_point(fstab, path);
+    Volume *rec = fs_mgr_get_entry_for_mount_point(fstab, path);
+
+    if (rec == NULL)
+        return rec;
+
+    if (strcmp(rec->fs_type, "ext4") == 0 || strcmp(rec->fs_type, "f2fs") == 0 ||
+            strcmp(rec->fs_type, "vfat") == 0) {
+        char *detected_fs_type = blkid_get_tag_value(NULL, "TYPE", rec->blk_device);
+
+        if (detected_fs_type == NULL)
+            return rec;
+
+        Volume *fetched_rec = rec;
+        while (rec != NULL && strcmp(rec->fs_type, detected_fs_type) != 0)
+            rec = fs_mgr_get_entry_for_mount_point_after(rec, fstab, path);
+
+        if (rec == NULL)
+            return fetched_rec;
+    }
+
+    return rec;
 }
 
 Volume* volume_for_label(const char* label) {
diff --git a/updater/Android.mk b/updater/Android.mk
index 9f9da06..1ea1fb7 100644
--- a/updater/Android.mk
+++ b/updater/Android.mk
@@ -28,6 +28,9 @@ LOCAL_STATIC_LIBRARIES += \
     libsparse_static \
     libz
 
+LOCAL_C_INCLUDES += external/e2fsprogs/lib
+LOCAL_STATIC_LIBRARIES += libext2_blkid libext2_uuid
+
 ifneq ($(BOARD_RECOVERY_BLDRMSG_OFFSET),)
     LOCAL_CFLAGS += -DBOARD_RECOVERY_BLDRMSG_OFFSET=$(BOARD_RECOVERY_BLDRMSG_OFFSET)
 endif
diff --git a/updater/install.c b/updater/install.c
index 8d569ff..43d5cfb 100644
--- a/updater/install.c
+++ b/updater/install.c
@@ -33,6 +33,7 @@
 #include <sys/xattr.h>
 #include <linux/xattr.h>
 #include <inttypes.h>
+#include <blkid/blkid.h>
 
 #include "bootloader.h"
 #include "applypatch/applypatch.h"
@@ -167,6 +168,16 @@ Value* MountFn(const char* name, State* state, int argc, Expr* argv[]) {
         }
         result = mount_point;
     } else {
+        char *detected_fs_type = blkid_get_tag_value(NULL, "TYPE", location);
+        if (detected_fs_type) {
+            uiPrintf(state, "detected filesystem %s for %s\n",
+                    detected_fs_type, location);
+            fs_type = detected_fs_type;
+        } else {
+            uiPrintf(state, "could not detect filesystem for %s, assuming %s\n",
+                    location, fs_type);
+        }
+
         if (mount(location, mount_point, fs_type,
                   MS_NOATIME | MS_NODEV | MS_NODIRATIME,
                   has_mount_options ? mount_options : "") < 0) {