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-rw-r--r--mysys/my_sync.c188
1 files changed, 188 insertions, 0 deletions
diff --git a/mysys/my_sync.c b/mysys/my_sync.c
new file mode 100644
index 00000000..6f8760c3
--- /dev/null
+++ b/mysys/my_sync.c
@@ -0,0 +1,188 @@
+/*
+ Copyright (c) 2003, 2011, Oracle and/or its affiliates
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+#include "mysys_priv.h"
+#include "mysys_err.h"
+#include <errno.h>
+
+
+ulong my_sync_count; /* Count number of sync calls */
+
+static void (*before_sync_wait)(void)= 0;
+static void (*after_sync_wait)(void)= 0;
+
+void thr_set_sync_wait_callback(void (*before_wait)(void),
+ void (*after_wait)(void))
+{
+ before_sync_wait= before_wait;
+ after_sync_wait= after_wait;
+}
+
+/*
+ Sync data in file to disk
+
+ SYNOPSIS
+ my_sync()
+ fd File descritor to sync
+ my_flags Flags (now only MY_WME is supported)
+
+ NOTE
+ If file system supports its, only file data is synced, not inode data.
+
+ MY_IGNORE_BADFD is useful when fd is "volatile" - not protected by a
+ mutex. In this case by the time of fsync(), fd may be already closed by
+ another thread, or even reassigned to a different file. With this flag -
+ MY_IGNORE_BADFD - such a situation will not be considered an error.
+ (which is correct behaviour, if we know that the other thread synced the
+ file before closing)
+
+ RETURN
+ 0 ok
+ -1 error
+*/
+
+int my_sync(File fd, myf my_flags)
+{
+ int res;
+ DBUG_ENTER("my_sync");
+ DBUG_PRINT("my",("fd: %d my_flags: %lu", fd, my_flags));
+
+ if (my_disable_sync)
+ DBUG_RETURN(0);
+
+ statistic_increment(my_sync_count,&THR_LOCK_open);
+
+ if (before_sync_wait)
+ (*before_sync_wait)();
+
+ do
+ {
+#if defined(F_FULLFSYNC)
+ /*
+ In Mac OS X >= 10.3 this call is safer than fsync() (it forces the
+ disk's cache and guarantees ordered writes).
+ */
+ if (!(res= fcntl(fd, F_FULLFSYNC, 0)))
+ break; /* ok */
+ /* Some file systems don't support F_FULLFSYNC and fail above: */
+ DBUG_PRINT("info",("fcntl(F_FULLFSYNC) failed, falling back"));
+#endif
+#if defined(HAVE_FDATASYNC) && HAVE_DECL_FDATASYNC
+ res= fdatasync(fd);
+#elif defined(HAVE_FSYNC)
+ res= fsync(fd);
+ if (res == -1 && errno == ENOLCK)
+ res= 0; /* Result Bug in Old FreeBSD */
+#elif defined(_WIN32)
+ res= my_win_fsync(fd);
+#else
+#error Cannot find a way to sync a file, durability in danger
+ res= 0; /* No sync (strange OS) */
+#endif
+ } while (res == -1 && errno == EINTR);
+
+ if (res)
+ {
+ int er= errno;
+ if (!(my_errno= er))
+ my_errno= -1; /* Unknown error */
+ if (after_sync_wait)
+ (*after_sync_wait)();
+ if ((my_flags & MY_IGNORE_BADFD) &&
+ (er == EBADF || er == EINVAL || er == EROFS))
+ {
+ DBUG_PRINT("info", ("ignoring errno %d", er));
+ res= 0;
+ }
+ else if (my_flags & MY_WME)
+ my_error(EE_SYNC, MYF(ME_BELL), my_filename(fd), my_errno);
+ }
+ else
+ {
+ if (after_sync_wait)
+ (*after_sync_wait)();
+ }
+ DBUG_RETURN(res);
+} /* my_sync */
+
+
+/*
+ Force directory information to disk.
+
+ SYNOPSIS
+ my_sync_dir()
+ dir_name the name of the directory
+ my_flags flags (MY_WME etc)
+
+ RETURN
+ 0 if ok, !=0 if error
+*/
+
+int my_sync_dir(const char *dir_name __attribute__((unused)),
+ myf my_flags __attribute__((unused)))
+{
+#ifdef NEED_EXPLICIT_SYNC_DIR
+ static const char cur_dir_name[]= {FN_CURLIB, 0};
+ File dir_fd;
+ int res= 0;
+ const char *correct_dir_name;
+ DBUG_ENTER("my_sync_dir");
+ DBUG_PRINT("my",("Dir: '%s' my_flags: %lu", dir_name, my_flags));
+ /* Sometimes the path does not contain an explicit directory */
+ correct_dir_name= (dir_name[0] == 0) ? cur_dir_name : dir_name;
+ /*
+ Syncing a dir may give EINVAL on tmpfs on Linux, which is ok.
+ EIO on the other hand is very important. Hence MY_IGNORE_BADFD.
+ */
+ if ((dir_fd= my_open(correct_dir_name, O_RDONLY, MYF(my_flags))) >= 0)
+ {
+ if (my_sync(dir_fd, MYF(my_flags | MY_IGNORE_BADFD)))
+ res= 2;
+ if (my_close(dir_fd, MYF(my_flags)))
+ res= 3;
+ }
+ else
+ res= 1;
+ DBUG_RETURN(res);
+#else
+ return 0;
+#endif
+}
+
+/*
+ Force directory information to disk.
+
+ SYNOPSIS
+ my_sync_dir_by_file()
+ file_name the name of a file in the directory
+ my_flags flags (MY_WME etc)
+
+ RETURN
+ 0 if ok, !=0 if error
+*/
+
+int my_sync_dir_by_file(const char *file_name __attribute__((unused)),
+ myf my_flags __attribute__((unused)))
+{
+#ifdef NEED_EXPLICIT_SYNC_DIR
+ char dir_name[FN_REFLEN];
+ size_t dir_name_length;
+ dirname_part(dir_name, file_name, &dir_name_length);
+ return my_sync_dir(dir_name, my_flags & ~MY_NOSYMLINKS);
+#else
+ return 0;
+#endif
+}