From bd96536637724413173271e8d5df1777f7879c29 Mon Sep 17 00:00:00 2001 From: moneromooo-monero Date: Fri, 15 May 2020 18:39:06 +0000 Subject: db_lmdb: test for mmap support at init time It'll make it clearer when a DB init failure is due to being on a filesystem which does not support mmap --- src/blockchain_db/lmdb/db_lmdb.cpp | 29 +++++++++++++++++++++++++++++ src/blockchain_db/lmdb/db_lmdb.h | 1 + 2 files changed, 30 insertions(+) diff --git a/src/blockchain_db/lmdb/db_lmdb.cpp b/src/blockchain_db/lmdb/db_lmdb.cpp index 5cec8879d..5cdbf44e8 100644 --- a/src/blockchain_db/lmdb/db_lmdb.cpp +++ b/src/blockchain_db/lmdb/db_lmdb.cpp @@ -25,6 +25,13 @@ // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +#ifndef _WIN32 +#include +#include +#include +#include +#endif + #include "db_lmdb.h" #include @@ -1287,6 +1294,26 @@ BlockchainLMDB::BlockchainLMDB(bool batch_transactions): BlockchainDB() m_hardfork = nullptr; } +void BlockchainLMDB::check_mmap_support() +{ +#ifndef _WIN32 + const boost::filesystem::path mmap_test_file = m_folder / boost::filesystem::unique_path(); + int mmap_test_fd = ::open(mmap_test_file.string().c_str(), O_RDWR | O_CREAT, 0600); + if (mmap_test_fd < 0) + throw0(DB_ERROR((std::string("Failed to check for mmap support: open failed: ") + strerror(errno)).c_str())); + epee::misc_utils::auto_scope_leave_caller scope_exit_handler = epee::misc_utils::create_scope_leave_handler([mmap_test_fd, &mmap_test_file]() { + ::close(mmap_test_fd); + boost::filesystem::remove(mmap_test_file.string()); + }); + if (write(mmap_test_fd, "mmaptest", 8) != 8) + throw0(DB_ERROR((std::string("Failed to check for mmap support: write failed: ") + strerror(errno)).c_str())); + void *mmap_res = mmap(NULL, 8, PROT_READ, MAP_SHARED, mmap_test_fd, 0); + if (mmap_res == MAP_FAILED) + throw0(DB_ERROR("This filesystem does not support mmap: use --data-dir to place the blockchain on a filesystem which does")); + munmap(mmap_res, 8); +#endif +} + void BlockchainLMDB::open(const std::string& filename, const int db_flags) { int result; @@ -1328,6 +1355,8 @@ void BlockchainLMDB::open(const std::string& filename, const int db_flags) m_folder = filename; + check_mmap_support(); + #ifdef __OpenBSD__ if ((mdb_flags & MDB_WRITEMAP) == 0) { MCLOG_RED(el::Level::Info, "global", "Running on OpenBSD: forcing WRITEMAP"); diff --git a/src/blockchain_db/lmdb/db_lmdb.h b/src/blockchain_db/lmdb/db_lmdb.h index 6ddeed671..ba91bd4d5 100644 --- a/src/blockchain_db/lmdb/db_lmdb.h +++ b/src/blockchain_db/lmdb/db_lmdb.h @@ -356,6 +356,7 @@ public: static int compare_string(const MDB_val *a, const MDB_val *b); private: + void check_mmap_support(); void do_resize(uint64_t size_increase=0); bool need_resize(uint64_t threshold_size=0) const; -- cgit v1.2.3