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Copyright (c) 2008, Sun Microsystems, Inc. All Rights Reserved.
Copyright 1989 AT&T
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
aio_reqp
cred_p
Copyright (c) 2008, Sun Microsystems, Inc. All Rights Reserved.
Copyright 1989 AT&T
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
AWRITE 9E "February 15, 2020"
NAME
awrite - asynchronous write to a device
SYNOPSIS
#include <sys/uio.h> #include <sys/aio_req.h> #include <sys/cred.h> #include <sys/ddi.h> #include <sys/sunddi.h> int prefixawrite(dev_t dev, struct aio_req *aio_reqp, cred_t *cred_p);
INTERFACE LEVEL
illumos DDI specific (illumos DDI). This entry point is optional. Drivers
that do not support an awrite() entry point should use nodev(9F)
PARAMETERS
dev
Device number.
Pointer to the aio_req(9S) structure that describes where the data is stored.
Pointer to the credential structure.
DESCRIPTION
The driver's awrite() routine is called to perform an asynchronous write.
getminor(9F) can be used to access the minor number component of the
dev argument. awrite() may use the credential structure pointed to
by cred_p to check for superuser access by calling drv_priv(9F).
The awrite() routine may also examine the uio(9S) structure
through the aio_req structure pointer, aio_reqp. awrite()
must call aphysio(9F) with the aio_req pointer and a pointer to the
driver's strategy(9E) routine.
No fields of the uio(9S) structure pointed to by aio_req, other than uio_offset or uio_loffset, may be modified for non-seekable devices.
RETURN VALUES
The awrite() routine should return 0 for success, or the
appropriate error number.
CONTEXT
This function is called from user context only.
EXAMPLES
Example 1 Using the awrite() routine:
The following is an example of an awrite() routine:
static int
xxawrite(dev_t dev, struct aio_req *aio, cred_t *cred_p)
{
int instance;
struct xxstate *xsp;
instance = getminor(dev);
xsp = ddi_get_soft_state(statep, instance);
/*Verify soft state structure has been allocated */
if (xsp == NULL)
return (ENXIO);
return (aphysio(xxstrategy, anocancel, dev, B_WRITE, \e
xxminphys, aio));
}
SEE ALSO
write(2), aiowrite(3C), aread(9E), read(9E),
strategy(9E), write(9E), anocancel(9F), aphysio(9F),
ddi_get_soft_state(9F), drv_priv(9F), getminor(9F),
minphys(9F), nodev(9F), aio_req(9S), cb_ops(9S),
uio(9S)
Writing Device Drivers
BUGS
There is no way other than calling aphysio(9F) to accomplish an
asynchronous write.