commit dc148de23ea1437f0e9f9794c8977ad6cf70f361
author Jerry Zhang <zhangjerry@google.com> Mon May 14 12:07:16 2018 -0700
committer Jerry Zhang <zhangjerry@google.com> Mon May 14 19:28:20 2018 +0000
tree 88fe154c746933e85ba24f1d3babd9851a3a3e28
parent bf2e1e8debbe1e91549b2defe2345d1a1876a8df

Call access(2) on all files/dirs modified by Mtp

External sdcards are accessed through /mnt/media_rw,
so access() each touched file for sdcardfs to update
its metadata. This is done for all created/deleted/renamed
folders and files.

Bug: 77849654
Test: use mtp with emulated sdcard
Change-Id: Ic8cef9dc90e9cbc9783ff45a87c481833f910665

media/mtp/MtpServer.cpp

diff --git a/media/mtp/MtpServer.cpp b/media/mtp/MtpServer.cpp
index 86d59dd..ccddd6e 100644
--- a/media/mtp/MtpServer.cpp
+++ b/media/mtp/MtpServer.cpp
@@ -809,7 +809,7 @@
     uint64_t finalsize = sstat.st_size;
     ALOGV("Sent a file over MTP. Time: %f s, Size: %" PRIu64 ", Rate: %f bytes/s",
             diff.count(), finalsize, ((double) finalsize) / diff.count());
-    close(mfr.fd);
+    closeObjFd(mfr.fd, filePath);
     return result;
 }
 
@@ -887,7 +887,7 @@
         else
             result = MTP_RESPONSE_GENERAL_ERROR;
     }
-    close(mfr.fd);
+    closeObjFd(mfr.fd, filePath);
     return result;
 }
 
@@ -1043,7 +1043,7 @@
 
     if (info.mStorageID == storageID) {
         ALOGV("Moving file from %s to %s", (const char*)fromPath, (const char*)path);
-        if (rename(fromPath, path)) {
+        if (renameTo(fromPath, path)) {
             PLOG(ERROR) << "rename() failed from " << fromPath << " to " << path;
             result = MTP_RESPONSE_GENERAL_ERROR;
         }
@@ -1226,7 +1226,7 @@
     }
 
     fstat(mfr.fd, &sstat);
-    close(mfr.fd);
+    closeObjFd(mfr.fd, mSendObjectFilePath);
 
     if (ret < 0) {
         ALOGE("Mtp receive file got error %s", strerror(errno));

media/mtp/MtpUtils.cpp

diff --git a/media/mtp/MtpUtils.cpp b/media/mtp/MtpUtils.cpp
index 51cfd7d..8564576 100644
--- a/media/mtp/MtpUtils.cpp
+++ b/media/mtp/MtpUtils.cpp
@@ -36,6 +36,13 @@
 
 constexpr unsigned long FILE_COPY_SIZE = 262144;
 
+static void access_ok(const char *path) {
+    if (access(path, F_OK) == -1) {
+        // Ignore. Failure could be common in cases of delete where
+        // the metadata was updated through other paths.
+    }
+}
+
 /*
 DateTime strings follow a compatible subset of the definition found in ISO 8601, and
 take the form of a Unicode string formatted as: "YYYYMMDDThhmmss.s". In this
@@ -101,6 +108,7 @@
     } else {
         chown((const char *)path, getuid(), FILE_GROUP);
     }
+    access_ok(path);
     return ret;
 }
 
@@ -181,6 +189,7 @@
     LOG(DEBUG) << "Copied a file with MTP. Time: " << diff.count() << " s, Size: " << length <<
         ", Rate: " << ((double) length) / diff.count() << " bytes/s";
     chown(toPath, getuid(), FILE_GROUP);
+    access_ok(toPath);
     return ret == -1 ? -1 : 0;
 }
 
@@ -212,6 +221,7 @@
         } else {
             success = unlink(childPath.c_str());
         }
+        access_ok(childPath.c_str());
         if (success == -1)
             PLOG(ERROR) << "Deleting path " << childPath << " failed";
     }
@@ -236,7 +246,22 @@
     }
     if (success == -1)
         PLOG(ERROR) << "Deleting path " << path << " failed";
+    access_ok(path);
     return success == 0;
 }
 
+int renameTo(const char *oldPath, const char *newPath) {
+    int ret = rename(oldPath, newPath);
+    access_ok(oldPath);
+    access_ok(newPath);
+    return ret;
+}
+
+// Calls access(2) on the path to update underlying filesystems,
+// then closes the fd.
+void closeObjFd(int fd, const char *path) {
+    close(fd);
+    access_ok(path);
+}
+
 }  // namespace android

media/mtp/MtpUtils.h

diff --git a/media/mtp/MtpUtils.h b/media/mtp/MtpUtils.h
index 744546b..21f5df0 100644
--- a/media/mtp/MtpUtils.h
+++ b/media/mtp/MtpUtils.h
@@ -34,7 +34,9 @@
 int copyRecursive(const char *fromPath, const char *toPath);
 int copyFile(const char *fromPath, const char *toPath);
 bool deletePath(const char* path);
+int renameTo(const char *oldPath, const char *newPath);
 
+void closeObjFd(int fd, const char *path);
 }; // namespace android
 
 #endif // _MTP_UTILS_H