Merge "Add support for esdfs mounting"
diff --git a/sdcard/sdcard.cpp b/sdcard/sdcard.cpp
index 574bbfe..dc36596 100644
--- a/sdcard/sdcard.cpp
+++ b/sdcard/sdcard.cpp
@@ -43,6 +43,44 @@
#include <private/android_filesystem_config.h>
+#define PROP_SDCARDFS_DEVICE "ro.sys.sdcardfs"
+#define PROP_SDCARDFS_USER "persist.sys.sdcardfs"
+
+static bool supports_esdfs(void) {
+ std::string filesystems;
+ if (!android::base::ReadFileToString("/proc/filesystems", &filesystems)) {
+ PLOG(ERROR) << "Could not read /proc/filesystems";
+ return false;
+ }
+ for (const auto& fs : android::base::Split(filesystems, "\n")) {
+ if (fs.find("esdfs") != std::string::npos) return true;
+ }
+ return false;
+}
+
+static bool should_use_sdcardfs(void) {
+ char property[PROPERTY_VALUE_MAX];
+
+ // Allow user to have a strong opinion about state
+ property_get(PROP_SDCARDFS_USER, property, "");
+ if (!strcmp(property, "force_on")) {
+ LOG(WARNING) << "User explicitly enabled sdcardfs";
+ return true;
+ } else if (!strcmp(property, "force_off")) {
+ LOG(WARNING) << "User explicitly disabled sdcardfs";
+ return !supports_esdfs();
+ }
+
+ // Fall back to device opinion about state
+ if (property_get_bool(PROP_SDCARDFS_DEVICE, true)) {
+ LOG(WARNING) << "Device explicitly enabled sdcardfs";
+ return true;
+ } else {
+ LOG(WARNING) << "Device explicitly disabled sdcardfs";
+ return !supports_esdfs();
+ }
+}
+
// NOTE: This is a vestigial program that simply exists to mount the in-kernel
// sdcardfs filesystem. The older FUSE-based design that used to live here has
// been completely removed to avoid confusion.
@@ -61,7 +99,7 @@
static bool sdcardfs_setup(const std::string& source_path, const std::string& dest_path,
uid_t fsuid, gid_t fsgid, bool multi_user, userid_t userid, gid_t gid,
- mode_t mask, bool derive_gid, bool default_normal) {
+ mode_t mask, bool derive_gid, bool default_normal, bool use_esdfs) {
// Try several attempts, each time with one less option, to gracefully
// handle older kernels that aren't updated yet.
for (int i = 0; i < 4; i++) {
@@ -72,7 +110,7 @@
auto opts = android::base::StringPrintf("fsuid=%d,fsgid=%d,%smask=%d,userid=%d,gid=%d",
fsuid, fsgid, new_opts.c_str(), mask, userid, gid);
- if (mount(source_path.c_str(), dest_path.c_str(), "sdcardfs",
+ if (mount(source_path.c_str(), dest_path.c_str(), use_esdfs ? "esdfs" : "sdcardfs",
MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_NOATIME, opts.c_str()) == -1) {
PLOG(WARNING) << "Failed to mount sdcardfs with options " << opts;
} else {
@@ -104,9 +142,21 @@
return true;
}
+static bool sdcardfs_setup_secondary(const std::string& default_path, const std::string& source_path,
+ const std::string& dest_path, uid_t fsuid, gid_t fsgid,
+ bool multi_user, userid_t userid, gid_t gid, mode_t mask,
+ bool derive_gid, bool default_normal, bool use_esdfs) {
+ if (use_esdfs) {
+ return sdcardfs_setup(source_path, dest_path, fsuid, fsgid, multi_user, userid, gid, mask,
+ derive_gid, default_normal, use_esdfs);
+ } else {
+ return sdcardfs_setup_bind_remount(default_path, dest_path, gid, mask);
+ }
+}
+
static void run_sdcardfs(const std::string& source_path, const std::string& label, uid_t uid,
gid_t gid, userid_t userid, bool multi_user, bool full_write,
- bool derive_gid, bool default_normal) {
+ bool derive_gid, bool default_normal, bool use_esdfs) {
std::string dest_path_default = "/mnt/runtime/default/" + label;
std::string dest_path_read = "/mnt/runtime/read/" + label;
std::string dest_path_write = "/mnt/runtime/write/" + label;
@@ -116,10 +166,13 @@
// Multi-user storage is fully isolated per user, so "other"
// permissions are completely masked off.
if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
- AID_SDCARD_RW, 0006, derive_gid, default_normal) ||
- !sdcardfs_setup_bind_remount(dest_path_default, dest_path_read, AID_EVERYBODY, 0027) ||
- !sdcardfs_setup_bind_remount(dest_path_default, dest_path_write, AID_EVERYBODY,
- full_write ? 0007 : 0027)) {
+ AID_SDCARD_RW, 0006, derive_gid, default_normal, use_esdfs) ||
+ !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_read, uid, gid,
+ multi_user, userid, AID_EVERYBODY, 0027, derive_gid,
+ default_normal, use_esdfs) ||
+ !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_write, uid, gid,
+ multi_user, userid, AID_EVERYBODY, full_write ? 0007 : 0027,
+ derive_gid, default_normal, use_esdfs)) {
LOG(FATAL) << "failed to sdcardfs_setup";
}
} else {
@@ -127,11 +180,13 @@
// the Android directories are masked off to a single user
// deep inside attr_from_stat().
if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
- AID_SDCARD_RW, 0006, derive_gid, default_normal) ||
- !sdcardfs_setup_bind_remount(dest_path_default, dest_path_read, AID_EVERYBODY,
- full_write ? 0027 : 0022) ||
- !sdcardfs_setup_bind_remount(dest_path_default, dest_path_write, AID_EVERYBODY,
- full_write ? 0007 : 0022)) {
+ AID_SDCARD_RW, 0006, derive_gid, default_normal, use_esdfs) ||
+ !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_read, uid, gid,
+ multi_user, userid, AID_EVERYBODY, full_write ? 0027 : 0022,
+ derive_gid, default_normal, use_esdfs) ||
+ !sdcardfs_setup_secondary(dest_path_default, source_path, dest_path_write, uid, gid,
+ multi_user, userid, AID_EVERYBODY, full_write ? 0007 : 0022,
+ derive_gid, default_normal, use_esdfs)) {
LOG(FATAL) << "failed to sdcardfs_setup";
}
}
@@ -242,6 +297,6 @@
}
run_sdcardfs(source_path, label, uid, gid, userid, multi_user, full_write, derive_gid,
- default_normal);
+ default_normal, !should_use_sdcardfs());
return 1;
}