freebsd-skq/sys/fs/nfsclient/nfs_clnode.c
rmacklem 6a6a18bf5c PR# 165923 reported intermittent write failures for dirty
memory mapped pages being written back on an NFS mount.
Since any thread can call VOP_PUTPAGES() to write back a
dirty page, the credentials of that thread may not have
write access to the file on an NFS server. (Often the uid
is 0, which may be mapped to "nobody" in the NFS server.)
Although there is no completely correct fix for this
(NFS servers check access on every write RPC instead of at
open/mmap time), this patch avoids the common cases by
holding onto a credential that recently opened the file
for writing and uses that credential for the write RPCs
being done by VOP_PUTPAGES() for both NFS clients.

Tested by:	Joel Ray Holveck (joelh at juniper.net)
PR:		kern/165923
Reviewed by:	kib
MFC after:	2 weeks
2012-05-12 12:02:51 +00:00

332 lines
8.6 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_node.c 8.6 (Berkeley) 5/22/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_kdtrace.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <sys/lock.h>
#include <sys/malloc.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 <fs/nfs/nfsport.h>
#include <fs/nfsclient/nfsnode.h>
#include <fs/nfsclient/nfsmount.h>
#include <fs/nfsclient/nfs.h>
#include <fs/nfsclient/nfs_kdtrace.h>
#include <nfs/nfs_lock.h>
extern struct vop_vector newnfs_vnodeops;
extern struct buf_ops buf_ops_newnfs;
MALLOC_DECLARE(M_NEWNFSREQ);
uma_zone_t newnfsnode_zone;
static void nfs_freesillyrename(void *arg, __unused int pending);
void
ncl_nhinit(void)
{
newnfsnode_zone = uma_zcreate("NCLNODE", sizeof(struct nfsnode), NULL,
NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
}
void
ncl_nhuninit(void)
{
uma_zdestroy(newnfsnode_zone);
}
/*
* ONLY USED FOR THE ROOT DIRECTORY. nfscl_nget() does the rest. If this
* function is going to be used to get Regular Files, code must be added
* to fill in the "struct nfsv4node".
* 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
ncl_nget(struct mount *mntp, u_int8_t *fhp, int fhsize, struct nfsnode **npp,
int lkflags)
{
struct thread *td = curthread; /* XXX */
struct nfsnode *np;
struct vnode *vp;
struct vnode *nvp;
int error;
u_int hash;
struct nfsmount *nmp;
struct nfsfh *nfhp;
nmp = VFSTONFS(mntp);
*npp = NULL;
hash = fnv_32_buf(fhp, fhsize, FNV1_32_INIT);
MALLOC(nfhp, struct nfsfh *, sizeof (struct nfsfh) + fhsize,
M_NFSFH, M_WAITOK);
bcopy(fhp, &nfhp->nfh_fh[0], fhsize);
nfhp->nfh_len = fhsize;
error = vfs_hash_get(mntp, hash, lkflags,
td, &nvp, newnfs_vncmpf, nfhp);
FREE(nfhp, M_NFSFH);
if (error)
return (error);
if (nvp != NULL) {
*npp = VTONFS(nvp);
return (0);
}
/*
* Allocate before getnewvnode since doing so afterward
* might cause a bogus v_data pointer to get dereferenced
* elsewhere if zalloc should block.
*/
np = uma_zalloc(newnfsnode_zone, M_WAITOK | M_ZERO);
error = getnewvnode("newnfs", mntp, &newnfs_vnodeops, &nvp);
if (error) {
uma_zfree(newnfsnode_zone, np);
return (error);
}
vp = nvp;
KASSERT(vp->v_bufobj.bo_bsize != 0, ("ncl_nget: bo_bsize == 0"));
vp->v_bufobj.bo_ops = &buf_ops_newnfs;
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, "NEWNFSnode lock", NULL, MTX_DEF | MTX_DUPOK);
/*
* NFS supports recursive and shared locking.
*/
lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_NOWITNESS, NULL);
VN_LOCK_AREC(vp);
VN_LOCK_ASHARE(vp);
/*
* Are we getting the root? If so, make sure the vnode flags
* are correct
*/
if ((fhsize == nmp->nm_fhsize) &&
!bcmp(fhp, nmp->nm_fh, fhsize)) {
if (vp->v_type == VNON)
vp->v_type = VDIR;
vp->v_vflag |= VV_ROOT;
}
MALLOC(np->n_fhp, struct nfsfh *, sizeof (struct nfsfh) + fhsize,
M_NFSFH, M_WAITOK);
bcopy(fhp, np->n_fhp->nfh_fh, fhsize);
np->n_fhp->nfh_len = fhsize;
error = insmntque(vp, mntp);
if (error != 0) {
*npp = NULL;
FREE((caddr_t)np->n_fhp, M_NFSFH);
mtx_destroy(&np->n_mtx);
uma_zfree(newnfsnode_zone, np);
return (error);
}
error = vfs_hash_insert(vp, hash, lkflags,
td, &nvp, newnfs_vncmpf, np->n_fhp);
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_NEWNFSREQ);
}
int
ncl_inactive(struct vop_inactive_args *ap)
{
struct nfsnode *np;
struct sillyrename *sp;
struct vnode *vp = ap->a_vp;
np = VTONFS(vp);
if (NFS_ISV4(vp) && vp->v_type == VREG) {
/*
* Since mmap()'d files do I/O after VOP_CLOSE(), the NFSv4
* Close operations are delayed until now. Any dirty buffers
* must be flushed before the close, so that the stateid is
* available for the writes.
*/
(void) ncl_flush(vp, MNT_WAIT, NULL, ap->a_td, 1, 0);
(void) nfsrpc_close(vp, 1, ap->a_td);
}
mtx_lock(&np->n_mtx);
if (vp->v_type != VDIR) {
sp = np->n_sillyrename;
np->n_sillyrename = NULL;
} else
sp = NULL;
if (sp) {
mtx_unlock(&np->n_mtx);
(void) ncl_vinvalbuf(vp, 0, ap->a_td, 1);
/*
* Remove the silly file that was rename'd earlier
*/
ncl_removeit(sp, vp);
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
ncl_reclaim(struct vop_reclaim_args *ap)
{
struct vnode *vp = ap->a_vp;
struct nfsnode *np = VTONFS(vp);
struct nfsdmap *dp, *dp2;
if (NFS_ISV4(vp) && vp->v_type == VREG)
/*
* Since mmap()'d files do I/O after VOP_CLOSE(), the NFSv4
* Close operations are delayed until ncl_inactive().
* However, since VOP_INACTIVE() is not guaranteed to be
* called, we need to do it again here.
*/
(void) nfsrpc_close(vp, 1, ap->a_td);
/*
* If the NLM is running, give it a chance to abort pending
* locks.
*/
if (nfs_reclaim_p != NULL)
nfs_reclaim_p(ap);
/*
* Destroy the vm object and flush associated pages.
*/
vnode_destroy_vobject(vp);
vfs_hash_remove(vp);
/*
* Call nfscl_reclaimnode() to save attributes in the delegation,
* as required.
*/
if (vp->v_type == VREG)
nfscl_reclaimnode(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);
FREE((caddr_t)np->n_fhp, M_NFSFH);
if (np->n_v4 != NULL)
FREE((caddr_t)np->n_v4, M_NFSV4NODE);
mtx_destroy(&np->n_mtx);
uma_zfree(newnfsnode_zone, vp->v_data);
vp->v_data = NULL;
return (0);
}
/*
* Invalidate both the access and attribute caches for this vnode.
*/
void
ncl_invalcaches(struct vnode *vp)
{
struct nfsnode *np = VTONFS(vp);
int i;
mtx_lock(&np->n_mtx);
for (i = 0; i < NFS_ACCESSCACHESIZE; i++)
np->n_accesscache[i].stamp = 0;
KDTRACE_NFS_ACCESSCACHE_FLUSH_DONE(vp);
np->n_attrstamp = 0;
KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
mtx_unlock(&np->n_mtx);
}