mariadb/mysys/my_redel.c
Vladislav Vaintroub c61c1d7ce1 MDEV-4576 : Aria storage engine's temporary files might not be deleted (Errcode : 13)
See also MySQL Bug #39750  and similar ones.

Fix my_delete() on Windows, to safely remvoe files on Windows, including files  that are opened by another threads in the same process, antiviruses and  backup applications. If file to be deleted is  also  opened by another thread, the file is renamed to unique name prior to deletion - this makes it possible to create file with the same name right after deletion.
With this patch my_delete_allow_opened() becomes obsolete and is replaced with my_delete().

This patch is rework of the patch  http://lists.mysql.com/commits/59327  for MySQL bug#39750.
2013-06-16 22:13:26 +02:00

154 lines
4.2 KiB
C

/*
Copyright (c) 2000, 2010, 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 02110-1301 USA */
#include "mysys_priv.h"
#include "mysys_err.h"
#include <my_dir.h>
#include <m_string.h>
#include "mysys_err.h"
#if defined(HAVE_UTIME_H)
#include <utime.h>
#elif defined(HAVE_SYS_UTIME_H)
#include <sys/utime.h>
#elif !defined(HPUX10)
struct utimbuf {
time_t actime;
time_t modtime;
};
#endif
/*
Rename with copy stat form old file
Copy stats from old file to new file, deletes orginal and
changes new file name to old file name
if MY_REDEL_MAKE_COPY is given, then the orginal file
is renamed to org_name-'current_time'.BAK
*/
#define REDEL_EXT ".BAK"
int my_redel(const char *org_name, const char *tmp_name,
time_t backup_time_stamp, myf MyFlags)
{
int error=1;
DBUG_ENTER("my_redel");
DBUG_PRINT("my",("org_name: '%s' tmp_name: '%s' MyFlags: %d",
org_name,tmp_name,MyFlags));
if (my_copystat(org_name,tmp_name,MyFlags) < 0)
goto end;
if (MyFlags & MY_REDEL_MAKE_BACKUP)
{
char name_buff[FN_REFLEN + MY_BACKUP_NAME_EXTRA_LENGTH];
my_create_backup_name(name_buff, org_name, backup_time_stamp);
if (my_rename(org_name, name_buff, MyFlags))
goto end;
}
else if (my_delete(org_name, MyFlags))
goto end;
if (my_rename(tmp_name,org_name,MyFlags))
goto end;
error=0;
end:
DBUG_RETURN(error);
} /* my_redel */
/**
Copy stat from one file to another
@fn my_copystat()
@param from Copy stat from this file
@param to Copy stat to this file
@param MyFlags Flags:
MY_WME Give error if something goes wrong
MY_FAE Abort operation if something goes wrong
If MY_FAE is not given, we don't return -1 for
errors from chown (which normally require root
privilege)
@return 0 ok
-1 if can't get stat,
1 if wrong type of file
*/
int my_copystat(const char *from, const char *to, int MyFlags)
{
MY_STAT statbuf;
if (my_stat(from, &statbuf, MyFlags) == NULL)
return -1; /* Can't get stat on input file */
if ((statbuf.st_mode & S_IFMT) != S_IFREG)
return 1;
/* Copy modes */
if (chmod(to, statbuf.st_mode & 07777))
{
my_errno= errno;
if (MyFlags & (MY_FAE+MY_WME))
my_error(EE_CHANGE_PERMISSIONS, MYF(ME_BELL+ME_WAITTANG), from, errno);
return -1;
}
#if !defined(__WIN__)
if (statbuf.st_nlink > 1 && MyFlags & MY_LINK_WARNING)
{
if (MyFlags & MY_LINK_WARNING)
my_error(EE_LINK_WARNING,MYF(ME_BELL+ME_WAITTANG),from,statbuf.st_nlink);
}
/* Copy ownership */
if (chown(to, statbuf.st_uid, statbuf.st_gid))
{
my_errno= errno;
if (MyFlags & MY_WME)
my_error(EE_CHANGE_OWNERSHIP, MYF(ME_BELL+ME_WAITTANG), from, errno);
if (MyFlags & MY_FAE)
return -1;
}
#endif /* !__WIN__ */
if (MyFlags & MY_COPYTIME)
{
struct utimbuf timep;
timep.actime = statbuf.st_atime;
timep.modtime = statbuf.st_mtime;
(void) utime((char*) to, &timep);/* Update last accessed and modified times */
}
return 0;
} /* my_copystat */
/**
Create a backup file name.
@fn my_create_backup_name()
@param to Store new file name here
@param from Original name
@info
The backup name is made by adding -YYMMDDHHMMSS.BAK to the file name
*/
void my_create_backup_name(char *to, const char *from, time_t backup_start)
{
char ext[MY_BACKUP_NAME_EXTRA_LENGTH+1];
ext[0]='-';
get_date(ext+1, GETDATE_SHORT_DATE | GETDATE_HHMMSSTIME, backup_start);
strmov(strend(ext),REDEL_EXT);
strmov(strmov(to, from), ext);
}