1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
/* Copyright (C) 2003 MySQL AB
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include "mysys_priv.h"
#include "mysys_err.h"
#include <errno.h>
/*
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;
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: */
#endif
#if defined(HAVE_FDATASYNC)
res= fdatasync(fd);
#elif defined(HAVE_FSYNC)
res= 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 ((my_flags & MY_IGNORE_BADFD) &&
(er == EBADF || er == EINVAL || er == EROFS))
{
res= 0;
}
else if (my_flags & MY_WME)
my_error(EE_SYNC, MYF(ME_BELL+ME_WAITTANG), my_filename(fd), my_errno);
}
return(res);
} /* my_sync */
static const char cur_dir_name[]= {FN_CURLIB, 0};
/*
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, myf my_flags)
{
#ifdef NEED_EXPLICIT_SYNC_DIR
File dir_fd;
int res= 0;
const char *correct_dir_name;
/* 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;
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, myf my_flags)
{
#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);
#else
return 0;
#endif
}
|