From 4500d49f362502c8f3117e335190d72e33bcd126 Mon Sep 17 00:00:00 2001 From: Howard Chu Date: Thu, 8 Jan 2015 13:03:55 +0000 Subject: [PATCH] fdatasync hack, again Check for ext3/ext4 fs, then check kernel version. --- libraries/liblmdb/mdb.c | 61 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c index 0867af7f52..264c15fc9f 100644 --- a/libraries/liblmdb/mdb.c +++ b/libraries/liblmdb/mdb.c @@ -1142,6 +1142,9 @@ struct MDB_env { #elif defined(MDB_USE_POSIX_SEM) sem_t *me_rmutex; /* Shared mutexes are not supported */ sem_t *me_wmutex; +#endif +#ifdef __linux + int me_fsynconly; /**< fdatasync is unreliable */ #endif void *me_userctx; /**< User-settable context */ MDB_assert_func *me_assert_func; /**< Callback for assertion failures */ @@ -2313,6 +2316,12 @@ mdb_env_sync(MDB_env *env, int force) rc = ErrCode(); #endif } else { +#ifdef __linux + if (env->me_fsynconly) { + if (fsync(env->me_fd)) + rc = ErrCode(); + } else +#endif if (MDB_FDATASYNC(env->me_fd)) rc = ErrCode(); } @@ -3850,6 +3859,11 @@ mdb_fsize(HANDLE fd, size_t *size) return MDB_SUCCESS; } +#ifdef __linux +#include +#include +#endif + /** Further setup required for opening an LMDB environment */ static int ESECT @@ -3867,6 +3881,53 @@ mdb_env_open2(MDB_env *env) else env->me_pidquery = PROCESS_QUERY_INFORMATION; #endif /* _WIN32 */ +#ifdef __linux + /* ext3/ext4 fdatasync is broken on some older Linux kernels. + * https://lkml.org/lkml/2012/9/3/83 + * Kernels after 3.6-rc6 are known good. + * https://lkml.org/lkml/2012/9/10/556 + * See if the DB is on ext3/ext4, then check for new enough kernel + * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known + * to be patched. + */ + { + struct statfs st; + fstatfs(env->me_fd, &st); + while (st.f_type == 0xEF53) { + struct utsname uts; + int i; + uname(&uts); + if (uts.release[0] < '3') { + if (!strncmp(uts.release, "2.6.32.", 7)) { + i = atoi(uts.release+7); + if (i >= 60) + break; /* 2.6.32.60 and newer is OK */ + } else if (!strncmp(uts.release, "2.6.34.", 7)) { + i = atoi(uts.release+7); + if (i >= 15) + break; /* 2.6.34.15 and newer is OK */ + } + } else if (uts.release[0] == '3') { + i = atoi(uts.release+2); + if (i > 5) + break; /* 3.6 and newer is OK */ + if (i == 5) { + i = atoi(uts.release+4); + if (i >= 4) + break; /* 3.5.4 and newer is OK */ + } else if (i == 2) { + i = atoi(uts.release+4); + if (i >= 30) + break; /* 3.2.30 and newer is OK */ + } + } else { /* 4.x and newer is OK */ + break; + } + env->me_fsynconly = 1; + break; + } + } +#endif memset(&meta, 0, sizeof(meta)); -- 2.39.2