freebsd-src/sys/nfsclient/nfs_node.c
Attilio Rao c6e0355cee r16312 is not any longer real since many years (likely since when VFS
received granular locking) but the comment present in UFS has been
copied all over other filesystems code incorrectly for several times.

Removes comments that makes no sense now.

Reviewed by:	kib
MFC after:	3 days
2012-11-19 22:43:45 +00:00

277 lines
6.8 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.
*
* @(#)nfs_node.c 8.6 (Berkeley) 5/22/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <sys/fnv_hash.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <sys/vnode.h>
#include <vm/uma.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs_lock.h>
#include <nfsclient/nfs.h>
#include <nfsclient/nfsnode.h>
#include <nfsclient/nfsmount.h>
static uma_zone_t nfsnode_zone;
static void nfs_freesillyrename(void *arg, __unused int pending);
#define TRUE 1
#define FALSE 0
void
nfs_nhinit(void)
{
nfsnode_zone = uma_zcreate("NFSNODE", sizeof(struct nfsnode), NULL,
NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
}
void
nfs_nhuninit(void)
{
uma_zdestroy(nfsnode_zone);
}
struct nfs_vncmp {
int fhsize;
void *fh;
};
static int
nfs_vncmpf(struct vnode *vp, void *arg)
{
struct nfs_vncmp *a;
struct nfsnode *np;
a = arg;
np = VTONFS(vp);
return (bcmp(a->fh, np->n_fhp, a->fhsize));
}
/*
* Look up a vnode/nfsnode by file handle.
* Callers must check for mount points!!
* In all cases, a pointer to a
* nfsnode structure is returned.
*/
int
nfs_nget(struct mount *mntp, nfsfh_t *fhp, int fhsize, struct nfsnode **npp, int flags)
{
struct thread *td = curthread; /* XXX */
struct nfsnode *np;
struct vnode *vp;
struct vnode *nvp;
int error;
u_int hash;
struct nfsmount *nmp;
struct nfs_vncmp ncmp;
nmp = VFSTONFS(mntp);
*npp = NULL;
hash = fnv_32_buf(fhp->fh_bytes, fhsize, FNV1_32_INIT);
ncmp.fhsize = fhsize;
ncmp.fh = fhp;
error = vfs_hash_get(mntp, hash, flags,
td, &nvp, nfs_vncmpf, &ncmp);
if (error)
return (error);
if (nvp != NULL) {
*npp = VTONFS(nvp);
return (0);
}
np = uma_zalloc(nfsnode_zone, M_WAITOK | M_ZERO);
error = getnewvnode("nfs", mntp, &nfs_vnodeops, &nvp);
if (error) {
uma_zfree(nfsnode_zone, np);
return (error);
}
vp = nvp;
vp->v_bufobj.bo_ops = &buf_ops_nfs;
vp->v_data = np;
np->n_vnode = vp;
/*
* Initialize the mutex even if the vnode is going to be a loser.
* This simplifies the logic in reclaim, which can then unconditionally
* destroy the mutex (in the case of the loser, or if hash_insert happened
* to return an error no special casing is needed).
*/
mtx_init(&np->n_mtx, "NFSnode lock", NULL, MTX_DEF);
/*
* NFS supports recursive and shared locking.
*/
lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_NOWITNESS, NULL);
VN_LOCK_AREC(vp);
VN_LOCK_ASHARE(vp);
if (fhsize > NFS_SMALLFH) {
np->n_fhp = malloc(fhsize, M_NFSBIGFH, M_WAITOK);
} else
np->n_fhp = &np->n_fh;
bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize);
np->n_fhsize = fhsize;
error = insmntque(vp, mntp);
if (error != 0) {
*npp = NULL;
if (np->n_fhsize > NFS_SMALLFH) {
free((caddr_t)np->n_fhp, M_NFSBIGFH);
}
mtx_destroy(&np->n_mtx);
uma_zfree(nfsnode_zone, np);
return (error);
}
error = vfs_hash_insert(vp, hash, flags,
td, &nvp, nfs_vncmpf, &ncmp);
if (error)
return (error);
if (nvp != NULL) {
*npp = VTONFS(nvp);
/* vfs_hash_insert() vput()'s the losing vnode */
return (0);
}
*npp = np;
return (0);
}
/*
* Do the vrele(sp->s_dvp) as a separate task in order to avoid a
* deadlock because of a LOR when vrele() locks the directory vnode.
*/
static void
nfs_freesillyrename(void *arg, __unused int pending)
{
struct sillyrename *sp;
sp = arg;
vrele(sp->s_dvp);
free(sp, M_NFSREQ);
}
int
nfs_inactive(struct vop_inactive_args *ap)
{
struct nfsnode *np;
struct sillyrename *sp;
struct thread *td = curthread; /* XXX */
np = VTONFS(ap->a_vp);
mtx_lock(&np->n_mtx);
if (ap->a_vp->v_type != VDIR) {
sp = np->n_sillyrename;
np->n_sillyrename = NULL;
} else
sp = NULL;
if (sp) {
mtx_unlock(&np->n_mtx);
(void)nfs_vinvalbuf(ap->a_vp, 0, td, 1);
/*
* Remove the silly file that was rename'd earlier
*/
(sp->s_removeit)(sp);
crfree(sp->s_cred);
TASK_INIT(&sp->s_task, 0, nfs_freesillyrename, sp);
taskqueue_enqueue(taskqueue_thread, &sp->s_task);
mtx_lock(&np->n_mtx);
}
np->n_flag &= NMODIFIED;
mtx_unlock(&np->n_mtx);
return (0);
}
/*
* Reclaim an nfsnode so that it can be used for other purposes.
*/
int
nfs_reclaim(struct vop_reclaim_args *ap)
{
struct vnode *vp = ap->a_vp;
struct nfsnode *np = VTONFS(vp);
struct nfsdmap *dp, *dp2;
/*
* If the NLM is running, give it a chance to abort pending
* locks.
*/
if (nfs_reclaim_p)
nfs_reclaim_p(ap);
/*
* Destroy the vm object and flush associated pages.
*/
vnode_destroy_vobject(vp);
vfs_hash_remove(vp);
/*
* Free up any directory cookie structures and
* large file handle structures that might be associated with
* this nfs node.
*/
if (vp->v_type == VDIR) {
dp = LIST_FIRST(&np->n_cookies);
while (dp) {
dp2 = dp;
dp = LIST_NEXT(dp, ndm_list);
free((caddr_t)dp2, M_NFSDIROFF);
}
}
if (np->n_writecred != NULL)
crfree(np->n_writecred);
if (np->n_fhsize > NFS_SMALLFH) {
free((caddr_t)np->n_fhp, M_NFSBIGFH);
}
mtx_destroy(&np->n_mtx);
uma_zfree(nfsnode_zone, vp->v_data);
vp->v_data = NULL;
return (0);
}