/*      $NetBSD: nfs_clnode.c,v 1.3 2016/12/13 22:17:33 pgoyette Exp $  */
/*-
* 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: head/sys/fs/nfsclient/nfs_clnode.c 302210 2016-06-26 14:18:28Z kib "); */
__RCSID("$NetBSD: nfs_clnode.c,v 1.3 2016/12/13 22:17:33 pgoyette Exp $");

#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/common/nfsport.h>
#include <fs/nfs/client/nfsnode.h>
#include <fs/nfs/client/nfsmount.h>
#include <fs/nfs/client/nfs.h>
#include <fs/nfs/client/nfs_kdtrace.h>

#include <fs/nfs/common/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;

const char nfs_vnode_tag[] = "nfs";

static void     nfs_freesillyrename(void *arg);

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);
       }
       np = uma_zalloc(newnfsnode_zone, M_WAITOK | M_ZERO);

       error = getnewvnode(nfs_vnode_tag, 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)
{
       struct sillyrename *sp;

       sp = arg;
       vrele(sp->s_dvp);
       free(sp, M_NEWNFSREQ);
}

static void
ncl_releasesillyrename(struct vnode *vp, struct thread *td)
{
       struct nfsnode *np;
       struct sillyrename *sp;

       ASSERT_VOP_ELOCKED(vp, "releasesillyrename");
       np = VTONFS(vp);
       mtx_assert(&np->n_mtx, MA_OWNED);
       if (vp->v_type != VDIR) {
               sp = np->n_sillyrename;
               np->n_sillyrename = NULL;
       } else
               sp = NULL;
       if (sp != NULL) {
               mtx_unlock(&np->n_mtx);
               (void) ncl_vinvalbuf(vp, 0, td, 1);
               /*
                * Remove the silly file that was rename'd earlier
                */
               ncl_removeit(sp, vp);
               crfree(sp->s_cred);
               sysmon_task_queue_sched(0, nfs_freesillyrename, sp);
               mtx_lock(&np->n_mtx);
       }
}

int
ncl_inactive(struct vop_inactive_args *ap)
{
       struct vnode *vp = ap->a_vp;
       struct nfsnode *np;
       boolean_t retv;

       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/pages must be flushed before the close, so that the
                * stateid is available for the writes.
                */
               if (vp->v_object != NULL) {
                       VM_OBJECT_WLOCK(vp->v_object);
                       retv = vm_object_page_clean(vp->v_object, 0, 0,
                           OBJPC_SYNC);
                       VM_OBJECT_WUNLOCK(vp->v_object);
               } else
                       retv = TRUE;
               if (retv == TRUE) {
                       (void)ncl_flush(vp, MNT_WAIT, NULL, ap->a_td, 1, 0);
                       (void)nfsrpc_close(vp, 1, ap->a_td);
               }
       }

       np = VTONFS(vp);
       mtx_lock(&np->n_mtx);
       ncl_releasesillyrename(vp, ap->a_td);

       /*
        * NMODIFIED means that there might be dirty/stale buffers
        * associated with the NFS vnode.  None of the other flags are
        * meaningful after the vnode is unused.
        */
       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 the NLM is running, give it a chance to abort pending
        * locks.
        */
       if (nfs_reclaim_p != NULL)
               nfs_reclaim_p(ap);

       mtx_lock(&np->n_mtx);
       ncl_releasesillyrename(vp, ap->a_td);
       mtx_unlock(&np->n_mtx);

       /*
        * Destroy the vm object and flush associated pages.
        */
       vnode_destroy_vobject(vp);

       if (NFS_ISV4(vp) && vp->v_type == VREG)
               /*
                * We can now safely close any remaining NFSv4 Opens for
                * this file. Most opens will have already been closed by
                * ncl_inactive(), but there are cases where it is not
                * called, so we need to do it again here.
                */
               (void) nfsrpc_close(vp, 1, ap->a_td);

       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);
}