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Merge "libfiemap_writer: Calculate FIBMAP blocks correctly."

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am: 9d3310c019

Change-Id: I37ff4a029fc722518a11caab744c4f5378e6eb3b
This commit is contained in:
David Anderson 2019-03-14 10:14:29 -07:00 committed by android-build-merger
commit 2cf4f08bd5
2 changed files with 72 additions and 8 deletions
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23
fs_mgr/libfiemap_writer/fiemap_writer.cpp
View file

@ -507,7 +507,17 @@ static bool ReadFibmap(int file_fd, const std::string& file_path,
return false;
}
uint64_t num_blocks = (s.st_size + s.st_blksize - 1) / s.st_blksize;
unsigned int blksize;
if (ioctl(file_fd, FIGETBSZ, &blksize) < 0) {
PLOG(ERROR) << "Failed to get FIGETBSZ for " << file_path;
return false;
}
if (!blksize) {
LOG(ERROR) << "Invalid filesystem block size: " << blksize;
return false;
}
uint64_t num_blocks = (s.st_size + blksize - 1) / blksize;
if (num_blocks > std::numeric_limits<uint32_t>::max()) {
LOG(ERROR) << "Too many blocks for FIBMAP (" << num_blocks << ")";
return false;
@ -525,13 +535,12 @@ static bool ReadFibmap(int file_fd, const std::string& file_path,
}
if (!extents->empty() && block == last_block + 1) {
extents->back().fe_length += s.st_blksize;
extents->back().fe_length += blksize;
} else {
extents->push_back(
fiemap_extent{.fe_logical = block_number,
.fe_physical = static_cast<uint64_t>(block) * s.st_blksize,
.fe_length = static_cast<uint64_t>(s.st_blksize),
.fe_flags = 0});
extents->push_back(fiemap_extent{.fe_logical = block_number,
.fe_physical = static_cast<uint64_t>(block) * blksize,
.fe_length = static_cast<uint64_t>(blksize),
.fe_flags = 0});
}
last_block = block;
}

57
fs_mgr/libfiemap_writer/fiemap_writer_test.cpp
View file

@ -196,6 +196,61 @@ TEST_F(FiemapWriterTest, MaxBlockSize) {
ASSERT_GT(DetermineMaximumFileSize(testfile), 0);
}
TEST_F(FiemapWriterTest, FibmapBlockAddressing) {
FiemapUniquePtr fptr = FiemapWriter::Open(testfile, gBlockSize);
ASSERT_NE(fptr, nullptr);
switch (fptr->fs_type()) {
case F2FS_SUPER_MAGIC:
case EXT4_SUPER_MAGIC:
// Skip the test for FIEMAP supported filesystems. This is really
// because f2fs/ext4 have caches that seem to defeat reading back
// directly from the block device, and writing directly is too
// dangerous.
std::cout << "Skipping test, filesystem does not use FIBMAP\n";
return;
}
bool uses_dm;
std::string bdev_path;
ASSERT_TRUE(FiemapWriter::GetBlockDeviceForFile(testfile, &bdev_path, &uses_dm));
if (uses_dm) {
// We could use a device-mapper wrapper here to bypass encryption, but
// really this test is for FIBMAP correctness on VFAT (where encryption
// is never used), so we don't bother.
std::cout << "Skipping test, block device is metadata encrypted\n";
return;
}
std::string data(fptr->size(), '\0');
for (size_t i = 0; i < data.size(); i++) {
data[i] = 'A' + static_cast<char>(data.size() % 26);
}
{
unique_fd fd(open(testfile.c_str(), O_WRONLY | O_CLOEXEC));
ASSERT_GE(fd, 0);
ASSERT_TRUE(android::base::WriteFully(fd, data.data(), data.size()));
ASSERT_EQ(fsync(fd), 0);
}
ASSERT_FALSE(fptr->extents().empty());
const auto& first_extent = fptr->extents()[0];
unique_fd bdev(open(fptr->bdev_path().c_str(), O_RDONLY | O_CLOEXEC));
ASSERT_GE(bdev, 0);
off_t where = first_extent.fe_physical;
ASSERT_EQ(lseek(bdev, where, SEEK_SET), where);
// Note: this will fail on encrypted folders.
std::string actual(data.size(), '\0');
ASSERT_GE(first_extent.fe_length, data.size());
ASSERT_TRUE(android::base::ReadFully(bdev, actual.data(), actual.size()));
EXPECT_EQ(memcmp(actual.data(), data.data(), data.size()), 0);
}
TEST_F(SplitFiemapTest, Create) {
auto ptr = SplitFiemap::Create(testfile, 1024 * 768, 1024 * 32);
ASSERT_NE(ptr, nullptr);
@ -446,7 +501,7 @@ int main(int argc, char** argv) {
if (argc <= 1) {
cerr << "Usage: <test_dir> [file_size]\n";
cerr << "\n";
cerr << "Note: test_dir must be a writable directory.\n";
cerr << "Note: test_dir must be a writable, unencrypted directory.\n";
exit(EXIT_FAILURE);
}
::android::base::InitLogging(argv, ::android::base::StderrLogger);