From c7ca3b6760d62651ad8c1a8fb2c2590c590720ad Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@google.com>
Date: Tue, 22 Jan 2019 14:54:02 -0800
Subject: [PATCH] Expose IsFilePinned through FiemapWriter.

This is needed for gsid to verify whether a file is pinned.

Bug: 122556707
Test: manual test
Change-Id: I662402294028597241ce11f86421f6ebb4a3cd6b
---
 fs_mgr/libfiemap_writer/fiemap_writer.cpp         | 15 +++++++++++++++
 fs_mgr/libfiemap_writer/fiemap_writer_test.cpp    |  8 ++++++++
 .../include/libfiemap_writer/fiemap_writer.h      | 12 ++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/fs_mgr/libfiemap_writer/fiemap_writer.cpp b/fs_mgr/libfiemap_writer/fiemap_writer.cpp
index 164fc9145..6ccdb5781 100644
--- a/fs_mgr/libfiemap_writer/fiemap_writer.cpp
+++ b/fs_mgr/libfiemap_writer/fiemap_writer.cpp
@@ -359,6 +359,21 @@ static bool IsFilePinned(int file_fd, const std::string& file_path, uint32_t fs_
     return moved_blocks_nr == 0;
 }
 
+bool FiemapWriter::HasPinnedExtents(const std::string& file_path) {
+    android::base::unique_fd fd(open(file_path.c_str(), O_NOFOLLOW | O_CLOEXEC | O_RDONLY));
+    if (fd < 0) {
+        PLOG(ERROR) << "open: " << file_path;
+        return false;
+    }
+
+    struct statfs64 sfs;
+    if (fstatfs64(fd, &sfs)) {
+        PLOG(ERROR) << "fstatfs64: " << file_path;
+        return false;
+    }
+    return IsFilePinned(fd, file_path, sfs.f_type);
+}
+
 static void LogExtent(uint32_t num, const struct fiemap_extent& ext) {
     LOG(INFO) << "Extent #" << num;
     LOG(INFO) << "  fe_logical:  " << ext.fe_logical;
diff --git a/fs_mgr/libfiemap_writer/fiemap_writer_test.cpp b/fs_mgr/libfiemap_writer/fiemap_writer_test.cpp
index 51015378c..3d20ff32d 100644
--- a/fs_mgr/libfiemap_writer/fiemap_writer_test.cpp
+++ b/fs_mgr/libfiemap_writer/fiemap_writer_test.cpp
@@ -51,6 +51,8 @@ class FiemapWriterTest : public ::testing::Test {
         testfile = ::android::base::StringPrintf("%s/testdata/%s", exec_dir.c_str(), tinfo->name());
     }
 
+    void TearDown() override { unlink(testfile.c_str()); }
+
     // name of the file we use for testing
     std::string testfile;
 };
@@ -102,6 +104,12 @@ TEST_F(FiemapWriterTest, CheckProgress) {
     EXPECT_EQ(invocations, 2);
 }
 
+TEST_F(FiemapWriterTest, CheckPinning) {
+    auto ptr = FiemapWriter::Open(testfile, 4096);
+    ASSERT_NE(ptr, nullptr);
+    EXPECT_TRUE(FiemapWriter::HasPinnedExtents(testfile));
+}
+
 TEST_F(FiemapWriterTest, CheckBlockDevicePath) {
     FiemapUniquePtr fptr = FiemapWriter::Open(testfile, 4096);
     EXPECT_EQ(fptr->size(), 4096);
diff --git a/fs_mgr/libfiemap_writer/include/libfiemap_writer/fiemap_writer.h b/fs_mgr/libfiemap_writer/include/libfiemap_writer/fiemap_writer.h
index ab78f9361..a0085cfe2 100644
--- a/fs_mgr/libfiemap_writer/include/libfiemap_writer/fiemap_writer.h
+++ b/fs_mgr/libfiemap_writer/include/libfiemap_writer/fiemap_writer.h
@@ -45,6 +45,18 @@ class FiemapWriter final {
                                 bool create = true,
                                 std::function<bool(uint64_t, uint64_t)> progress = {});
 
+    // Check that a file still has the same extents since it was last opened with FiemapWriter,
+    // assuming the file was not resized outside of FiemapWriter. Returns false either on error
+    // or if the file was not pinned.
+    //
+    // This will always return true on Ext4. On F2FS, it will return true if either of the
+    // following cases are true:
+    //   - The file was never pinned.
+    //   - The file is pinned and has not been moved by the GC.
+    // Thus, this method should only be called for pinned files (such as those returned by
+    // FiemapWriter::Open).
+    static bool HasPinnedExtents(const std::string& file_path);
+
     // Syncs block device writes.
     bool Flush() const;