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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997,2007 Oracle. All rights reserved.
*
* $Id: os_rw.c,v 1.6 2007/05/17 15:15:47 bostic Exp $
*/
#include "db_config.h"
#include "db_int.h"
/*
* __os_io --
* Do an I/O.
*/
int
__os_io(dbenv, op, fhp, pgno, pgsize, relative, io_len, buf, niop)
DB_ENV *dbenv;
int op;
DB_FH *fhp;
db_pgno_t pgno;
u_int32_t pgsize, relative, io_len;
u_int8_t *buf;
size_t *niop;
{
int ret;
MUTEX_LOCK(dbenv, fhp->mtx_fh);
if ((ret = __os_seek(dbenv, fhp, pgno, pgsize, relative)) != 0)
goto err;
switch (op) {
case DB_IO_READ:
ret = __os_read(dbenv, fhp, buf, io_len, niop);
break;
case DB_IO_WRITE:
ret = __os_write(dbenv, fhp, buf, io_len, niop);
break;
default:
ret = EINVAL;
break;
}
err: MUTEX_UNLOCK(dbenv, fhp->mtx_fh);
return (ret);
}
/*
* __os_read --
* Read from a file handle.
*/
int
__os_read(dbenv, fhp, addr, len, nrp)
DB_ENV *dbenv;
DB_FH *fhp;
void *addr;
size_t len;
size_t *nrp;
{
FileInfo pInfo;
int ret;
ret = 0;
if ((*nrp = (size_t)IFILE_Read(fhp->ifp, addr, len)) != len) {
IFILE_GetInfo(fhp->ifp, &pInfo);
if (pInfo.dwSize != 0) {
ret = __os_get_syserr();
__db_syserr(dbenv, ret, "IFILE_Read: %#lx, %lu",
P_TO_ULONG(addr), (u_long)len);
ret = __os_posix_err(ret);
}
}
return (ret);
}
/*
* __os_write --
* Write to a file handle.
*/
int
__os_write(dbenv, fhp, addr, len, nwp)
DB_ENV *dbenv;
DB_FH *fhp;
void *addr;
size_t len;
size_t *nwp;
{
#ifdef HAVE_FILESYSTEM_NOTZERO
/* Zero-fill as necessary. */
if (__os_fs_notzero()) {
int ret;
if ((ret = __os_zerofill(dbenv, fhp)) != 0)
return (ret);
}
#endif
return (__os_physwrite(dbenv, fhp, addr, len, nwp));
}
/*
* __os_physwrite --
* Physical write to a file handle.
*/
int
__os_physwrite(dbenv, fhp, addr, len, nwp)
DB_ENV *dbenv;
DB_FH *fhp;
void *addr;
size_t len;
size_t *nwp;
{
int ret;
/*
* Make a last "panic" check. Imagine a thread of control running in
* Berkeley DB, going to sleep. Another thread of control decides to
* run recovery because the environment is broken. The first thing
* recovery does is panic the existing environment, but we only check
* the panic flag when crossing the public API. If the sleeping thread
* wakes up and writes something, we could have two threads of control
* writing the log files at the same time. So, before writing, make a
* last panic check. Obviously, there's still a window, but it's very,
* very small.
*/
PANIC_CHECK(dbenv);
ret = 0;
if ((*nwp = (size_t)IFILE_Write(fhp->ifp, addr, len)) != len) {
ret = __os_get_syserr();
__db_syserr(dbenv, ret, "IFILE_Write: %#lx, %lu",
P_TO_ULONG(addr), (u_long)len);
ret = __os_posix_err(ret);
}
return (ret);
}
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