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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997, 2012 Oracle and/or its affiliates. All rights reserved.
*
* $Id$
*/
#include "db_config.h"
#include "db_int.h"
/*
* __os_open --
* Open a file descriptor (including page size and log size information).
*
* PUBLIC: int __os_open __P((ENV *,
* PUBLIC: const char *, u_int32_t, u_int32_t, int, DB_FH **));
*/
int
__os_open(env, name, page_size, flags, mode, fhpp)
ENV *env;
const char *name;
u_int32_t page_size, flags;
int mode;
DB_FH **fhpp;
{
DB_ENV *dbenv;
DB_FH *fhp;
int oflags, ret;
COMPQUIET(page_size, 0);
dbenv = env == NULL ? NULL : env->dbenv;
*fhpp = NULL;
oflags = 0;
if (dbenv != NULL &&
FLD_ISSET(dbenv->verbose, DB_VERB_FILEOPS | DB_VERB_FILEOPS_ALL))
__db_msg(env, DB_STR_A("0152",
"fileops: open %s", "%s"), name);
#undef OKFLAGS
#define OKFLAGS \
(DB_OSO_ABSMODE | DB_OSO_CREATE | DB_OSO_DIRECT | DB_OSO_DSYNC |\
DB_OSO_EXCL | DB_OSO_RDONLY | DB_OSO_REGION | DB_OSO_SEQ | \
DB_OSO_TEMP | DB_OSO_TRUNC)
if ((ret = __db_fchk(env, "__os_open", flags, OKFLAGS)) != 0)
return (ret);
#if defined(O_BINARY)
/*
* If there's a binary-mode open flag, set it, we never want any
* kind of translation. Some systems do translations by default,
* e.g., with Cygwin, the default mode for an open() is set by the
* mode of the mount that underlies the file.
*/
oflags |= O_BINARY;
#endif
/*
* DB requires the POSIX 1003.1 semantic that two files opened at the
* same time with DB_OSO_CREATE/O_CREAT and DB_OSO_EXCL/O_EXCL flags
* set return an EEXIST failure in at least one.
*/
if (LF_ISSET(DB_OSO_CREATE))
oflags |= O_CREAT;
if (LF_ISSET(DB_OSO_EXCL))
oflags |= O_EXCL;
#ifdef HAVE_O_DIRECT
if (LF_ISSET(DB_OSO_DIRECT))
oflags |= O_DIRECT;
#endif
#ifdef O_DSYNC
if (LF_ISSET(DB_OSO_DSYNC))
oflags |= O_DSYNC;
#endif
if (LF_ISSET(DB_OSO_RDONLY))
oflags |= O_RDONLY;
else
oflags |= O_RDWR;
if (LF_ISSET(DB_OSO_TRUNC))
oflags |= O_TRUNC;
/*
* Undocumented feature: allow applications to create intermediate
* directories whenever a file is opened.
*/
if (dbenv != NULL &&
env->dir_mode != 0 && LF_ISSET(DB_OSO_CREATE) &&
(ret = __db_mkpath(env, name)) != 0)
return (ret);
/* Open the file. */
#ifdef HAVE_QNX
if (LF_ISSET(DB_OSO_REGION))
ret = __os_qnx_region_open(env, name, oflags, mode, &fhp);
else
#endif
ret = __os_openhandle(env, name, oflags, mode, &fhp);
if (ret != 0)
return (ret);
if (LF_ISSET(DB_OSO_REGION))
F_SET(fhp, DB_FH_REGION);
#ifdef HAVE_FCHMOD
/*
* If the code using Berkeley DB is a library, that code may not be able
* to control the application's umask value. Allow applications to set
* absolute file modes. We can't fix the race between file creation and
* the fchmod call -- we can't modify the process' umask here since the
* process may be multi-threaded and the umask value is per-process, not
* per-thread.
*/
if (LF_ISSET(DB_OSO_CREATE) && LF_ISSET(DB_OSO_ABSMODE))
(void)fchmod(fhp->fd, mode);
#endif
#ifdef O_DSYNC
/*
* If we can configure the file descriptor to flush on write, the
* file descriptor does not need to be explicitly sync'd.
*/
if (LF_ISSET(DB_OSO_DSYNC))
F_SET(fhp, DB_FH_NOSYNC);
#endif
#if defined(HAVE_DIRECTIO) && defined(DIRECTIO_ON)
/*
* The Solaris C library includes directio, but you have to set special
* compile flags to #define DIRECTIO_ON. Require both in order to call
* directio.
*/
if (LF_ISSET(DB_OSO_DIRECT))
(void)directio(fhp->fd, DIRECTIO_ON);
#endif
/*
* Delete any temporary file.
*
* !!!
* There's a race here, where we've created a file and we crash before
* we can unlink it. Temporary files aren't common in DB, regardless,
* it's not a security problem because the file is empty. There's no
* reasonable way to avoid the race (playing signal games isn't worth
* the portability nightmare), so we just live with it.
*/
if (LF_ISSET(DB_OSO_TEMP)) {
#if defined(HAVE_UNLINK_WITH_OPEN_FAILURE) || defined(CONFIG_TEST)
F_SET(fhp, DB_FH_UNLINK);
#else
(void)__os_unlink(env, name, 0);
#endif
}
*fhpp = fhp;
return (0);
}
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