freebsd-dev/sys/nfs/nfs_node.c
Kirk McKusick d6514f21d7 In preparation for deprecating CIRCLEQ macros in favor of TAILQ
macros which provide the same functionality and are a bit more
efficient, convert use of CIRCLEQ's in NFS to TAILQ's.
2000-11-14 08:00:39 +00:00

405 lines
10 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_node.c 8.6 (Berkeley) 5/22/95
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <vm/vm_zone.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsnode.h>
#include <nfs/nfsmount.h>
static vm_zone_t nfsnode_zone;
static LIST_HEAD(nfsnodehashhead, nfsnode) *nfsnodehashtbl;
static u_long nfsnodehash;
#define TRUE 1
#define FALSE 0
/*
* Initialize hash links for nfsnodes
* and build nfsnode free list.
*/
void
nfs_nhinit()
{
nfsnode_zone = zinit("NFSNODE", sizeof(struct nfsnode), 0, 0, 1);
nfsnodehashtbl = hashinit(desiredvnodes, M_NFSHASH, &nfsnodehash);
}
/*
* Compute an entry in the NFS hash table structure
*/
u_long
nfs_hash(fhp, fhsize)
register nfsfh_t *fhp;
int fhsize;
{
register u_char *fhpp;
register u_long fhsum;
register int i;
fhpp = &fhp->fh_bytes[0];
fhsum = 0;
for (i = 0; i < fhsize; i++)
fhsum += *fhpp++;
return (fhsum);
}
/*
* 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.
*/
static int nfs_node_hash_lock;
int
nfs_nget(mntp, fhp, fhsize, npp)
struct mount *mntp;
register nfsfh_t *fhp;
int fhsize;
struct nfsnode **npp;
{
struct proc *p = curproc; /* XXX */
struct nfsnode *np, *np2;
struct nfsnodehashhead *nhpp;
register struct vnode *vp;
struct vnode *nvp;
int error;
int rsflags;
struct nfsmount *nmp;
/*
* Calculate nfs mount point and figure out whether the rslock should
* be interruptable or not.
*/
nmp = VFSTONFS(mntp);
if (nmp->nm_flag & NFSMNT_INT)
rsflags = PCATCH;
else
rsflags = 0;
retry:
nhpp = NFSNOHASH(nfs_hash(fhp, fhsize));
loop:
for (np = nhpp->lh_first; np != 0; np = np->n_hash.le_next) {
if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize ||
bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize))
continue;
vp = NFSTOV(np);
if (vget(vp, LK_EXCLUSIVE, p))
goto loop;
*npp = np;
return(0);
}
/*
* Obtain a lock to prevent a race condition if the getnewvnode()
* or MALLOC() below happens to block.
*/
if (nfs_node_hash_lock) {
while (nfs_node_hash_lock) {
nfs_node_hash_lock = -1;
tsleep(&nfs_node_hash_lock, PVM, "nfsngt", 0);
}
goto loop;
}
nfs_node_hash_lock = 1;
/*
* Allocate before getnewvnode since doing so afterward
* might cause a bogus v_data pointer to get dereferenced
* elsewhere if zalloc should block.
*/
np = zalloc(nfsnode_zone);
error = getnewvnode(VT_NFS, mntp, nfsv2_vnodeop_p, &nvp);
if (error) {
if (nfs_node_hash_lock < 0)
wakeup(&nfs_node_hash_lock);
nfs_node_hash_lock = 0;
*npp = 0;
zfree(nfsnode_zone, np);
return (error);
}
vp = nvp;
bzero((caddr_t)np, sizeof *np);
vp->v_data = np;
np->n_vnode = vp;
/*
* Insert the nfsnode in the hash queue for its new file handle
*/
for (np2 = nhpp->lh_first; np2 != 0; np2 = np2->n_hash.le_next) {
if (mntp != NFSTOV(np2)->v_mount || np2->n_fhsize != fhsize ||
bcmp((caddr_t)fhp, (caddr_t)np2->n_fhp, fhsize))
continue;
vrele(vp);
if (nfs_node_hash_lock < 0)
wakeup(&nfs_node_hash_lock);
nfs_node_hash_lock = 0;
zfree(nfsnode_zone, np);
goto retry;
}
LIST_INSERT_HEAD(nhpp, np, n_hash);
if (fhsize > NFS_SMALLFH) {
MALLOC(np->n_fhp, nfsfh_t *, 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;
lockinit(&np->n_rslock, PVFS | rsflags, "nfrslk", 0, LK_NOPAUSE);
lockinit(&vp->v_lock, PVFS, "nfsnlk", 0, LK_NOPAUSE);
*npp = np;
if (nfs_node_hash_lock < 0)
wakeup(&nfs_node_hash_lock);
nfs_node_hash_lock = 0;
/*
* Lock the new nfsnode.
*/
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (0);
}
int
nfs_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct proc *a_p;
} */ *ap;
{
register struct nfsnode *np;
register struct sillyrename *sp;
struct proc *p = curproc; /* XXX */
np = VTONFS(ap->a_vp);
if (prtactive && ap->a_vp->v_usecount != 0)
vprint("nfs_inactive: pushing active", ap->a_vp);
if (ap->a_vp->v_type != VDIR) {
sp = np->n_sillyrename;
np->n_sillyrename = (struct sillyrename *)0;
} else
sp = (struct sillyrename *)0;
if (sp) {
/*
* We need a reference to keep the vnode from being
* recycled by getnewvnode while we do the I/O
* associated with discarding the buffers unless we
* are being forcibly unmounted in which case we already
* have our own reference.
*/
if (ap->a_vp->v_usecount > 0)
(void) nfs_vinvalbuf(ap->a_vp, 0, sp->s_cred, p, 1);
else if (vget(ap->a_vp, 0, p))
panic("nfs_inactive: lost vnode");
else {
(void) nfs_vinvalbuf(ap->a_vp, 0, sp->s_cred, p, 1);
vrele(ap->a_vp);
}
/*
* Remove the silly file that was rename'd earlier
*/
nfs_removeit(sp);
crfree(sp->s_cred);
vrele(sp->s_dvp);
FREE((caddr_t)sp, M_NFSREQ);
}
np->n_flag &= (NMODIFIED | NFLUSHINPROG | NFLUSHWANT | NQNFSEVICTED |
NQNFSNONCACHE | NQNFSWRITE);
VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
return (0);
}
/*
* Reclaim an nfsnode so that it can be used for other purposes.
*/
int
nfs_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
register struct nfsnode *np = VTONFS(vp);
register struct nfsmount *nmp = VFSTONFS(vp->v_mount);
register struct nfsdmap *dp, *dp2;
if (prtactive && vp->v_usecount != 0)
vprint("nfs_reclaim: pushing active", vp);
if (np->n_hash.le_prev != NULL)
LIST_REMOVE(np, n_hash);
/*
* For nqnfs, take it off the timer queue as required.
*/
if ((nmp->nm_flag & NFSMNT_NQNFS) && TAILQ_NEXT(np, n_timer) != 0) {
TAILQ_REMOVE(&nmp->nm_timerhead, np, n_timer);
}
/*
* 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 = np->n_cookies.lh_first;
while (dp) {
dp2 = dp;
dp = dp->ndm_list.le_next;
FREE((caddr_t)dp2, M_NFSDIROFF);
}
}
if (np->n_fhsize > NFS_SMALLFH) {
FREE((caddr_t)np->n_fhp, M_NFSBIGFH);
}
lockdestroy(&np->n_rslock);
cache_purge(vp);
zfree(nfsnode_zone, vp->v_data);
vp->v_data = (void *)0;
return (0);
}
#if 0
/*
* Lock an nfsnode
*/
int
nfs_lock(ap)
struct vop_lock_args /* {
struct vnode *a_vp;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
/*
* Ugh, another place where interruptible mounts will get hung.
* If you make this sleep interruptible, then you have to fix all
* the VOP_LOCK() calls to expect interruptibility.
*/
while (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
(void) tsleep((caddr_t)vp, PINOD, "nfslck", 0);
}
if (vp->v_tag == VT_NON)
return (ENOENT);
#if 0
/*
* Only lock regular files. If a server crashed while we were
* holding a directory lock, we could easily end up sleeping
* until the server rebooted while holding a lock on the root.
* Locks are only needed for protecting critical sections in
* VMIO at the moment.
* New vnodes will have type VNON but they should be locked
* since they may become VREG. This is checked in loadattrcache
* and unwanted locks are released there.
*/
if (vp->v_type == VREG || vp->v_type == VNON) {
while (np->n_flag & NLOCKED) {
np->n_flag |= NWANTED;
(void) tsleep((caddr_t) np, PINOD, "nfslck2", 0);
/*
* If the vnode has transmuted into a VDIR while we
* were asleep, then skip the lock.
*/
if (vp->v_type != VREG && vp->v_type != VNON)
return (0);
}
np->n_flag |= NLOCKED;
}
#endif
return (0);
}
/*
* Unlock an nfsnode
*/
int
nfs_unlock(ap)
struct vop_unlock_args /* {
struct vnode *a_vp;
} */ *ap;
{
#if 0
struct vnode* vp = ap->a_vp;
struct nfsnode* np = VTONFS(vp);
if (vp->v_type == VREG || vp->v_type == VNON) {
if (!(np->n_flag & NLOCKED))
panic("nfs_unlock: nfsnode not locked");
np->n_flag &= ~NLOCKED;
if (np->n_flag & NWANTED) {
np->n_flag &= ~NWANTED;
wakeup((caddr_t) np);
}
}
#endif
return (0);
}
/*
* Check for a locked nfsnode
*/
int
nfs_islocked(ap)
struct vop_islocked_args /* {
struct vnode *a_vp;
struct proc *a_p;
} */ *ap;
{
return VTONFS(ap->a_vp)->n_flag & NLOCKED ? 1 : 0;
}
#endif