commit 11c2d380a786d9e304416be98881b90b74ff666d
author Jeff Sharkey <jsharkey@android.com> Mon Sep 11 10:32:01 2017 -0600
committer Jeff Sharkey <jsharkey@android.com> Mon Sep 11 18:44:17 2017 -0600
tree 9d751c5daa6f601465c320977aaa6d79d81bfee1
parent a94fc7cdcd853923c84b903e89257b80a53b6410

Move even more vold commands over to Binder.

This moves fstrim, obb and appfuse commands over to the new Binder
interface.  This change also separates creating/destroying and
mounting/unmounting of OBB volumes, which means they finally flow
nicely into the modern VolumeInfo/VolumeBase design.

We now generate unique identifiers for all OBB volumes, instead of
using a shady MD5 hash.

Change all "loop" and "dm" devices to tag the kernel resources with
a vold-specific prefix so that we can clean them up if vold crashes;
there are new destroyAll() methods that handle this cleanup.

Move appfuse mounting/unmounting into VolumeManager so it can be
shared.  Move various model objects into a separate directory to
tidy things up.

Test: cts-tradefed run commandAndExit cts-dev -m CtsOsTestCases -t android.os.storage.cts.StorageManagerTest
Bug: 13758960
Change-Id: I7294e32b3fb6efe07cb3b77bd20166e70b66958f

Loop.cpp

diff --git a/Loop.cpp b/Loop.cpp
index 6ec5e6d..325b0d3 100644
--- a/Loop.cpp
+++ b/Loop.cpp
@@ -45,6 +45,8 @@
 using android::base::StringPrintf;
 using android::base::unique_fd;
 
+static const char* kVoldPrefix = "vold:";
+
 int Loop::dumpState(SocketClient *c) {
     int i;
     int fd;
@@ -87,7 +89,10 @@
     return 0;
 }
 
-int Loop::lookupActive(const char *id, char *buffer, size_t len) {
+int Loop::lookupActive(const char *id_raw, char *buffer, size_t len) {
+    auto id_string = StringPrintf("%s%s", kVoldPrefix, id_raw);
+    const char* id = id_string.c_str();
+
     int i;
     int fd;
     char filename[256];
@@ -134,7 +139,10 @@
     return 0;
 }
 
-int Loop::create(const char *id, const char *loopFile, char *loopDeviceBuffer, size_t len) {
+int Loop::create(const char *id_raw, const char *loopFile, char *loopDeviceBuffer, size_t len) {
+    auto id_string = StringPrintf("%s%s", kVoldPrefix, id_raw);
+    const char* id = id_string.c_str();
+
     int i;
     int fd;
     char filename[256];
@@ -267,6 +275,14 @@
         return -errno;
     }
 
+    struct loop_info64 li;
+    memset(&li, 0, sizeof(li));
+    strlcpy((char*) li.lo_crypt_name, kVoldPrefix, LO_NAME_SIZE);
+    if (ioctl(device_fd.get(), LOOP_SET_STATUS64, &li) == -1) {
+        PLOG(ERROR) << "Failed to LOOP_SET_STATUS64";
+        return -errno;
+    }
+
     return 0;
 }
 
@@ -289,9 +305,36 @@
     return 0;
 }
 
-int Loop::destroyByFile(const char * /*loopFile*/) {
-    errno = ENOSYS;
-    return -1;
+int Loop::destroyAll() {
+    for (int i = 0; i < LOOP_MAX; i++) {
+        auto path = StringPrintf("/dev/block/loop%d", i);
+
+        unique_fd fd(open(path.c_str(), O_RDWR | O_CLOEXEC));
+        if (fd.get() == -1) {
+            if (errno != ENOENT) {
+                PLOG(WARNING) << "Failed to open " << path;
+            }
+            continue;
+        }
+
+        struct loop_info64 li;
+        if (ioctl(fd.get(), LOOP_GET_STATUS64, &li) < 0) {
+            PLOG(WARNING) << "Failed to LOOP_GET_STATUS64 " << path;
+            continue;
+        }
+
+        char* id = (char*) li.lo_crypt_name;
+        if (strncmp(id, kVoldPrefix, strlen(kVoldPrefix)) == 0) {
+            LOG(DEBUG) << "Tearing down stale loop device at " << path << " named " << id;
+
+            if (ioctl(fd.get(), LOOP_CLR_FD, 0) < 0) {
+                PLOG(WARNING) << "Failed to LOOP_CLR_FD " << path;
+            }
+        } else {
+            LOG(VERBOSE) << "Found unmanaged loop device at " << path << " named " << id;
+        }
+    }
+    return 0;
 }
 
 int Loop::createImageFile(const char *file, unsigned long numSectors) {