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[block-cache] fix potential file descriptor leak

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Encapsulate file descriptor into an object, to ensure that an fd will be
closed properly while exception raised, e.g., the block_cache throws
exception during the block_manager's construction.
This commit is contained in:
Ming-Hung Tsai
2020-02-22 17:37:22 +08:00
parent c85ea5ef76
commit 955e11bc28
9 changed files with 42 additions and 32 deletions
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28
base/file_utils.cc
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@ -39,14 +39,16 @@ namespace {
//----------------------------------------------------------------
int
file_utils::open_file(string const &path, int flags) {
int fd = ::open(path.c_str(), OPEN_FLAGS | flags, DEFAULT_MODE);
if (fd < 0)
file_utils::file_descriptor::file_descriptor(string const &path, int flags) {
fd_ = ::open(path.c_str(), OPEN_FLAGS | flags, DEFAULT_MODE);
if (fd_ < 0)
syscall_failed("open",
"Note: you cannot run this tool with these options on live metadata.");
}
return fd;
file_utils::file_descriptor::~file_descriptor() {
close(fd_);
fd_ = -1;
}
bool
@ -76,7 +78,7 @@ file_utils::check_file_exists(string const &file, bool must_be_regular_file) {
throw runtime_error("Not a regular file");
}
int
file_utils::file_descriptor
file_utils::create_block_file(string const &path, off_t file_size) {
if (file_exists(path)) {
ostringstream out;
@ -84,16 +86,16 @@ file_utils::create_block_file(string const &path, off_t file_size) {
throw runtime_error(out.str());
}
int fd = open_file(path, O_CREAT | O_EXCL | O_RDWR);
file_descriptor fd(path, O_CREAT | O_EXCL | O_RDWR);
int r = ::ftruncate(fd, file_size);
int r = ::ftruncate(fd.fd_, file_size);
if (r < 0)
syscall_failed("ftruncate");
return fd;
}
int
file_utils::file_descriptor
file_utils::open_block_file(string const &path, off_t min_size, bool writeable, bool excl) {
if (!file_exists(path)) {
ostringstream out;
@ -105,7 +107,7 @@ file_utils::open_block_file(string const &path, off_t min_size, bool writeable,
if (excl)
flags |= O_EXCL;
return open_file(path, flags);
return file_descriptor(path, flags);
}
uint64_t
@ -146,17 +148,15 @@ file_utils::zero_superblock(std::string const &path)
{
char *buffer;
unsigned const SUPERBLOCK_SIZE = 4096;
int fd = open_block_file(path, SUPERBLOCK_SIZE, true, true);
file_descriptor fd = open_block_file(path, SUPERBLOCK_SIZE, true, true);
buffer = reinterpret_cast<char *>(aligned_alloc(SUPERBLOCK_SIZE, SUPERBLOCK_SIZE));
if (!buffer)
throw runtime_error("out of memory");
memset(buffer, 0, SUPERBLOCK_SIZE);
if (::write(fd, buffer, SUPERBLOCK_SIZE) != SUPERBLOCK_SIZE)
if (::write(fd.fd_, buffer, SUPERBLOCK_SIZE) != SUPERBLOCK_SIZE)
throw runtime_error("couldn't zero superblock");
::close(fd);
}
//----------------------------------------------------------------