freebsd-nq/sys/nfsclient/nfs_nfsiod.c
Scott Long 316ec49abd Some kernel threads try to do significant work, and the default KSTACK_PAGES
doesn't give them enough stack to do much before blowing away the pcb.
This adds MI and MD code to allow the allocation of an alternate kstack
who's size can be speficied when calling kthread_create.  Passing the
value 0 prevents the alternate kstack from being created.  Note that the
ia64 MD code is missing for now, and PowerPC was only partially written
due to the pmap.c being incomplete there.
Though this patch does not modify anything to make use of the alternate
kstack, acpi and usb are good candidates.

Reviewed by:	jake, peter, jhb
2002-10-02 07:44:29 +00:00

290 lines
7.9 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*
* @(#)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 <nfs/xdr_subs.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfsclient/nfs.h>
#include <nfsclient/nfsm_subs.h>
#include <nfsclient/nfsmount.h>
#include <nfsclient/nfsnode.h>
#include <nfsclient/nfs_lock.h>
static MALLOC_DEFINE(M_NFSSVC, "NFS srvsock", "Nfs server structure");
static void nfssvc_iod(void *);
static int nfs_asyncdaemon[NFS_MAXASYNCDAEMON];
SYSCTL_DECL(_vfs_nfs);
/* Maximum number of seconds a nfsiod kthread will sleep before exiting */
static unsigned int nfs_iodmaxidle = 120;
SYSCTL_UINT(_vfs_nfs, OID_AUTO, iodmaxidle, CTLFLAG_RW, &nfs_iodmaxidle, 0, "");
/* Maximum number of nfsiod kthreads */
static unsigned int nfs_iodmax = 20;
/* Minimum number of nfsiod kthreads to keep as spares */
static unsigned int nfs_iodmin = 4;
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);
if (newmin > nfs_iodmax)
return (EINVAL);
nfs_iodmin = newmin;
if (nfs_numasync >= nfs_iodmin)
return (0);
/*
* If the current number of nfsiod is lower
* than the new minimum, create some more.
*/
for (i = nfs_iodmin - nfs_numasync; i > 0; i--)
nfs_nfsiodnew();
return (0);
}
SYSCTL_PROC(_vfs_nfs, 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 = nfs_iodmax;
error = sysctl_handle_int(oidp, &newmax, 0, req);
if (error || (req->newptr == NULL))
return (error);
if (newmax > NFS_MAXASYNCDAEMON)
return (EINVAL);
nfs_iodmax = newmax;
if (nfs_numasync <= nfs_iodmax)
return (0);
/*
* If there are some asleep nfsiods that should
* exit, wakeup() them so that they check nfs_iodmax
* and exit. Those who are active will exit as
* soon as they finish I/O.
*/
iod = nfs_numasync - 1;
for (i = 0; i < nfs_numasync - nfs_iodmax; i++) {
if (nfs_iodwant[iod])
wakeup((caddr_t)&nfs_iodwant[iod]);
iod--;
}
return (0);
}
SYSCTL_PROC(_vfs_nfs, OID_AUTO, iodmax, CTLTYPE_UINT | CTLFLAG_RW, 0,
sizeof (nfs_iodmax), sysctl_iodmax, "IU", "");
int
nfs_nfsiodnew(void)
{
int error, i;
int newiod;
if (nfs_numasync >= nfs_iodmax)
return (-1);
newiod = -1;
for (i = 0; i < nfs_iodmax; i++)
if (nfs_asyncdaemon[i] == 0) {
nfs_asyncdaemon[i]++;
newiod = i;
break;
}
if (newiod == -1)
return (-1);
error = kthread_create(nfssvc_iod, nfs_asyncdaemon + i, NULL, RFHIGHPID,
0, "nfsiod %d", newiod);
if (error)
return (-1);
nfs_numasync++;
return (newiod);
}
static void
nfsiod_setup(void *dummy)
{
int i;
int error;
TUNABLE_INT_FETCH("vfs.nfs.iodmin", &nfs_iodmin);
/* Silently limit the start number of nfsiod's */
if (nfs_iodmin > NFS_MAXASYNCDAEMON)
nfs_iodmin = NFS_MAXASYNCDAEMON;
for (i = 0; i < nfs_iodmin; i++) {
error = nfs_nfsiodnew();
if (error == -1)
panic("nfsiod_setup: nfs_nfsiodnew failed");
}
}
SYSINIT(nfsiod, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, nfsiod_setup, NULL);
static int nfs_defect = 0;
SYSCTL_INT(_vfs_nfs, OID_AUTO, defect, CTLFLAG_RW, &nfs_defect, 0, "");
int
nfsclnt(struct thread *td, struct nfsclnt_args *uap)
{
struct lockd_ans la;
int error;
if ((uap->flag & NFSCLNT_LOCKDANS) != 0) {
error = copyin(uap->argp, &la, sizeof(la));
return (error != 0 ? error : nfslockdans(td, &la));
}
return EINVAL;
}
/*
* 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(&Giant);
myiod = (int *)instance - nfs_asyncdaemon;
/*
* Main loop
*/
for (;;) {
while (((nmp = nfs_iodmount[myiod]) == NULL
|| !TAILQ_FIRST(&nmp->nm_bufq))
&& error == 0) {
if (myiod >= nfs_iodmax)
goto finish;
if (nmp)
nmp->nm_bufqiods--;
nfs_iodwant[myiod] = curthread->td_proc;
nfs_iodmount[myiod] = NULL;
/*
* Always keep at least nfs_iodmin kthreads.
*/
timo = (myiod < nfs_iodmin) ? 0 : nfs_iodmaxidle * hz;
error = tsleep((caddr_t)&nfs_iodwant[myiod], PWAIT | PCATCH,
"nfsidl", timo);
}
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 <= nfs_numasync) {
nmp->nm_bufqwant = 0;
wakeup(&nmp->nm_bufq);
}
if (bp->b_iocmd == BIO_READ)
(void) nfs_doio(bp, bp->b_rcred, NULL);
else
(void) nfs_doio(bp, bp->b_wcred, NULL);
/*
* 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));
nfs_iodmount[myiod] = NULL;
nmp->nm_bufqiods--;
break;
}
}
}
finish:
nfs_asyncdaemon[myiod] = 0;
if (nmp)
nmp->nm_bufqiods--;
nfs_iodwant[myiod] = NULL;
nfs_iodmount[myiod] = NULL;
nfs_numasync--;
if ((error == 0) || (error == EWOULDBLOCK))
kthread_exit(0);
/* Abnormal termination */
kthread_exit(1);
}