openldap/servers/slurpd/lock.c
Hallvard Furuseth f0688d71a1 Locks were not always released, in particular if something went wrong.
Fixed in slurpd and the slapd main dir.  Slapd clients were not examined.
It also "felt right" to swap the order of closing dfp and rfp in slurpd
copy_replog(), so the last acquired lock is unlocked first.
1998-11-11 19:17:25 +00:00

140 lines
2.5 KiB
C

/*
* Copyright (c) 1996 Regents of the University of Michigan.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and that due credit is given
* to the University of Michigan at Ann Arbor. The name of the University
* may not be used to endorse or promote products derived from this
* software without specific prior written permission. This software
* is provided ``as is'' without express or implied warranty.
*/
/*
* lock.c - routines to open and apply an advisory lock to a file
*/
#include "portable.h"
#include <stdio.h>
#include <ac/string.h>
#include <ac/socket.h>
#include <ac/time.h>
#include <ac/unistd.h>
#include <sys/file.h>
#include <sys/param.h>
#include "../slapd/slap.h"
FILE *
lock_fopen(
char *fname,
char *type,
FILE **lfp
)
{
FILE *fp;
char buf[MAXPATHLEN];
/* open the lock file */
strcpy( buf, fname );
strcat( buf, ".lock" );
if ( (*lfp = fopen( buf, "w" )) == NULL ) {
Debug( LDAP_DEBUG_ANY,
"Error: could not open \"%s\"\n", buf, 0, 0 );
return( NULL );
}
/* acquire the lock */
#ifdef HAVE_FLOCK
while ( flock( fileno( *lfp ), LOCK_EX ) != 0 )
#else
while ( lockf( fileno( *lfp ), F_LOCK, 0 ) != 0 )
#endif
{
; /* NULL */
}
/* open the log file */
if ( (fp = fopen( fname, type )) == NULL ) {
Debug( LDAP_DEBUG_ANY,
"Error: could not open \"%s\"\n", fname, 0, 0 );
#ifdef HAVE_FLOCK
flock( fileno( *lfp ), LOCK_UN );
#else
lockf( fileno( *lfp ), F_ULOCK, 0 );
#endif
fclose( *lfp );
*lfp = NULL;
return( NULL );
}
return( fp );
}
int
lock_fclose(
FILE *fp,
FILE *lfp
)
{
/* unlock */
#ifdef HAVE_FLOCK
flock( fileno( lfp ), LOCK_UN );
#else
lockf( fileno( lfp ), F_ULOCK, 0 );
#endif
fclose( lfp );
return( fclose( fp ) );
}
/*
* Apply an advisory lock on a file. Just calls lock_fopen()
*/
int
acquire_lock(
char *file,
FILE **rfp,
FILE **lfp
)
{
if (( *rfp = lock_fopen( file, "r+", lfp )) == NULL ) {
Debug( LDAP_DEBUG_ANY,
"Error: acquire_lock(%d): Could not acquire lock on \"%s\"\n",
getpid(), file, 0);
return( -1 );
}
return( 0 );
}
/*
* Relinquish a lock on a file. Calls lock_fclose() and also removes the
* lock file.
*/
int
relinquish_lock(
char *file,
FILE *rfp,
FILE *lfp
)
{
if ( lock_fclose( rfp, lfp ) == EOF ) {
Debug( LDAP_DEBUG_ANY,
"Error: relinquish_lock (%d): Error closing \"%s\"\n",
getpid(), file, 0 );
return( -1 );
}
return( 0 );
}