freebsd-skq/sys/fs/nfsclient/nfs_clnfsiod.c
Rick Macklem 9ec7b004d0 Add the experimental nfs subtree to the kernel, that includes
support for NFSv4 as well as NFSv2 and 3.
	It lives in 3 subdirs under sys/fs:
	nfs - functions that are common to the client and server
	nfsclient - a mutation of sys/nfsclient that call generic functions
	to do RPCs and handle state. As such, it retains the
	buffer cache handling characteristics and vnode semantics that
	are found in sys/nfsclient, for the most part.
	nfsserver - the server. It includes a DRC designed specifically for
	NFSv4, that is used instead of the generic DRC in sys/rpc.
	The build glue will be checked in later, so at this point, it
	consists of 3 new subdirs that should not affect kernel building.

Approved by:	kib (mentor)
2009-05-04 15:23:58 +00:00

309 lines
8.2 KiB
C

/*-
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from nfs_syscalls.c 8.5 (Berkeley) 3/30/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/namei.h>
#include <sys/unistd.h>
#include <sys/kthread.h>
#include <sys/fcntl.h>
#include <sys/lockf.h>
#include <sys/mutex.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <fs/nfs/nfsport.h>
#include <fs/nfsclient/nfsmount.h>
#include <fs/nfsclient/nfs.h>
#include <fs/nfsclient/nfsnode.h>
#include <fs/nfsclient/nfs_lock.h>
extern struct mtx ncl_iod_mutex;
int ncl_numasync;
struct proc *ncl_iodwant[NFS_MAXRAHEAD];
struct nfsmount *ncl_iodmount[NFS_MAXRAHEAD];
static void nfssvc_iod(void *);
static int nfs_asyncdaemon[NFS_MAXRAHEAD];
SYSCTL_DECL(_vfs_newnfs);
/* Maximum number of seconds a nfsiod kthread will sleep before exiting */
static unsigned int ncl_iodmaxidle = 120;
SYSCTL_UINT(_vfs_newnfs, OID_AUTO, iodmaxidle, CTLFLAG_RW, &ncl_iodmaxidle, 0, "");
/* Maximum number of nfsiod kthreads */
unsigned int ncl_iodmax = NFS_MAXRAHEAD;
/* Minimum number of nfsiod kthreads to keep as spares */
static unsigned int nfs_iodmin = 0;
static int
sysctl_iodmin(SYSCTL_HANDLER_ARGS)
{
int error, i;
int newmin;
newmin = nfs_iodmin;
error = sysctl_handle_int(oidp, &newmin, 0, req);
if (error || (req->newptr == NULL))
return (error);
mtx_lock(&ncl_iod_mutex);
if (newmin > ncl_iodmax) {
error = EINVAL;
goto out;
}
nfs_iodmin = newmin;
if (ncl_numasync >= nfs_iodmin)
goto out;
/*
* If the current number of nfsiod is lower
* than the new minimum, create some more.
*/
for (i = nfs_iodmin - ncl_numasync; i > 0; i--)
ncl_nfsiodnew();
out:
mtx_unlock(&ncl_iod_mutex);
return (0);
}
SYSCTL_PROC(_vfs_newnfs, OID_AUTO, iodmin, CTLTYPE_UINT | CTLFLAG_RW, 0,
sizeof (nfs_iodmin), sysctl_iodmin, "IU", "");
static int
sysctl_iodmax(SYSCTL_HANDLER_ARGS)
{
int error, i;
int iod, newmax;
newmax = ncl_iodmax;
error = sysctl_handle_int(oidp, &newmax, 0, req);
if (error || (req->newptr == NULL))
return (error);
if (newmax > NFS_MAXRAHEAD)
return (EINVAL);
mtx_lock(&ncl_iod_mutex);
ncl_iodmax = newmax;
if (ncl_numasync <= ncl_iodmax)
goto out;
/*
* If there are some asleep nfsiods that should
* exit, wakeup() them so that they check ncl_iodmax
* and exit. Those who are active will exit as
* soon as they finish I/O.
*/
iod = ncl_numasync - 1;
for (i = 0; i < ncl_numasync - ncl_iodmax; i++) {
if (ncl_iodwant[iod])
wakeup(&ncl_iodwant[iod]);
iod--;
}
out:
mtx_unlock(&ncl_iod_mutex);
return (0);
}
SYSCTL_PROC(_vfs_newnfs, OID_AUTO, iodmax, CTLTYPE_UINT | CTLFLAG_RW, 0,
sizeof (ncl_iodmax), sysctl_iodmax, "IU", "");
int
ncl_nfsiodnew(void)
{
int error, i;
int newiod;
if (ncl_numasync >= ncl_iodmax)
return (-1);
newiod = -1;
for (i = 0; i < ncl_iodmax; i++)
if (nfs_asyncdaemon[i] == 0) {
nfs_asyncdaemon[i]++;
newiod = i;
break;
}
if (newiod == -1)
return (-1);
mtx_unlock(&ncl_iod_mutex);
error = kproc_create(nfssvc_iod, nfs_asyncdaemon + i, NULL, RFHIGHPID,
0, "nfsiod %d", newiod);
mtx_lock(&ncl_iod_mutex);
if (error)
return (-1);
ncl_numasync++;
return (newiod);
}
static void
nfsiod_setup(void *dummy)
{
int i;
int error;
TUNABLE_INT_FETCH("vfs.newnfs.iodmin", &nfs_iodmin);
nfscl_init();
mtx_lock(&ncl_iod_mutex);
/* Silently limit the start number of nfsiod's */
if (nfs_iodmin > NFS_MAXRAHEAD)
nfs_iodmin = NFS_MAXRAHEAD;
for (i = 0; i < nfs_iodmin; i++) {
error = ncl_nfsiodnew();
if (error == -1)
panic("newnfsiod_setup: ncl_nfsiodnew failed");
}
mtx_unlock(&ncl_iod_mutex);
}
SYSINIT(newnfsiod, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, nfsiod_setup, NULL);
static int nfs_defect = 0;
SYSCTL_INT(_vfs_newnfs, OID_AUTO, defect, CTLFLAG_RW, &nfs_defect, 0, "");
/*
* Asynchronous I/O daemons for client nfs.
* They do read-ahead and write-behind operations on the block I/O cache.
* Returns if we hit the timeout defined by the iodmaxidle sysctl.
*/
static void
nfssvc_iod(void *instance)
{
struct buf *bp;
struct nfsmount *nmp;
int myiod, timo;
int error = 0;
mtx_lock(&ncl_iod_mutex);
myiod = (int *)instance - nfs_asyncdaemon;
/*
* Main loop
*/
for (;;) {
while (((nmp = ncl_iodmount[myiod]) == NULL)
|| !TAILQ_FIRST(&nmp->nm_bufq)) {
if (myiod >= ncl_iodmax)
goto finish;
if (nmp)
nmp->nm_bufqiods--;
ncl_iodwant[myiod] = curthread->td_proc;
ncl_iodmount[myiod] = NULL;
/*
* Always keep at least nfs_iodmin kthreads.
*/
timo = (myiod < nfs_iodmin) ? 0 : ncl_iodmaxidle * hz;
error = msleep(&ncl_iodwant[myiod], &ncl_iod_mutex, PWAIT | PCATCH,
"-", timo);
if (error) {
nmp = ncl_iodmount[myiod];
/*
* Rechecking the nm_bufq closes a rare race where the
* nfsiod is woken up at the exact time the idle timeout
* fires
*/
if (nmp && TAILQ_FIRST(&nmp->nm_bufq))
error = 0;
break;
}
}
if (error)
break;
while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) {
/* Take one off the front of the list */
TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist);
nmp->nm_bufqlen--;
if (nmp->nm_bufqwant && nmp->nm_bufqlen <= ncl_numasync) {
nmp->nm_bufqwant = 0;
wakeup(&nmp->nm_bufq);
}
mtx_unlock(&ncl_iod_mutex);
if (bp->b_flags & B_DIRECT) {
KASSERT((bp->b_iocmd == BIO_WRITE), ("nfscvs_iod: BIO_WRITE not set"));
(void)ncl_doio_directwrite(bp);
} else {
if (bp->b_iocmd == BIO_READ)
(void) ncl_doio(bp->b_vp, bp, bp->b_rcred, NULL);
else
(void) ncl_doio(bp->b_vp, bp, bp->b_wcred, NULL);
}
mtx_lock(&ncl_iod_mutex);
/*
* If there are more than one iod on this mount, then defect
* so that the iods can be shared out fairly between the mounts
*/
if (nfs_defect && nmp->nm_bufqiods > 1) {
NFS_DPF(ASYNCIO,
("nfssvc_iod: iod %d defecting from mount %p\n",
myiod, nmp));
ncl_iodmount[myiod] = NULL;
nmp->nm_bufqiods--;
break;
}
}
}
finish:
nfs_asyncdaemon[myiod] = 0;
if (nmp)
nmp->nm_bufqiods--;
ncl_iodwant[myiod] = NULL;
ncl_iodmount[myiod] = NULL;
/* Someone may be waiting for the last nfsiod to terminate. */
if (--ncl_numasync == 0)
wakeup(&ncl_numasync);
mtx_unlock(&ncl_iod_mutex);
if ((error == 0) || (error == EWOULDBLOCK))
kproc_exit(0);
/* Abnormal termination */
kproc_exit(1);
}