/*      $OpenBSD: nfs_bio.c,v 1.87 2024/09/18 05:21:19 jsg Exp $        */
/*      $NetBSD: nfs_bio.c,v 1.25.4.2 1996/07/08 20:47:04 jtc 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.
 * 3. 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_bio.c   8.9 (Berkeley) 3/30/95
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/queue.h>
#include <sys/time.h>

#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsmount.h>
#include <nfs/nfsnode.h>
#include <nfs/nfs_var.h>

extern int nfs_numasync;
extern struct nfsstats nfsstats;
struct nfs_bufqhead nfs_bufq;
uint32_t nfs_bufqmax, nfs_bufqlen;

struct buf *nfs_getcacheblk(struct vnode *, daddr_t, int, struct proc *);

/*
 * Vnode op for read using bio
 * Any similarity to readip() is purely coincidental
 */
int
nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
{
        struct nfsnode *np = VTONFS(vp);
        int biosize, diff;
        struct buf *bp = NULL, *rabp;
        struct vattr vattr;
        struct proc *p;
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        daddr_t lbn, bn, rabn;
        caddr_t baddr;
        int got_buf = 0, nra, error = 0, n = 0, on = 0, not_readin;
        off_t offdiff;

#ifdef DIAGNOSTIC
        if (uio->uio_rw != UIO_READ)
                panic("nfs_read mode");
#endif
        if (uio->uio_resid == 0)
                return (0);
        if (uio->uio_offset < 0)
                return (EINVAL);
        p = uio->uio_procp;
        if ((nmp->nm_flag & (NFSMNT_NFSV3 | NFSMNT_GOTFSINFO)) == NFSMNT_NFSV3)
                (void)nfs_fsinfo(nmp, vp, cred, p);
        biosize = nmp->nm_rsize;
        /*
         * For nfs, cache consistency can only be maintained approximately.
         * Although RFC1094 does not specify the criteria, the following is
         * believed to be compatible with the reference port.
         * For nfs:
         * If the file's modify time on the server has changed since the
         * last read rpc or you have written to the file,
         * you may have lost data cache consistency with the
         * server, so flush all of the file's data out of the cache.
         * Then force a getattr rpc to ensure that you have up to date
         * attributes.
         */
        if (np->n_flag & NMODIFIED) {
                NFS_INVALIDATE_ATTRCACHE(np);
                error = VOP_GETATTR(vp, &vattr, cred, p);
                if (error)
                        return (error);
                np->n_mtime = vattr.va_mtime;
        } else {
                error = VOP_GETATTR(vp, &vattr, cred, p);
                if (error)
                        return (error);
                if (timespeccmp(&np->n_mtime, &vattr.va_mtime, !=)) {
                        error = nfs_vinvalbuf(vp, V_SAVE, cred, p);
                        if (error)
                                return (error);
                        np->n_mtime = vattr.va_mtime;
                }
        }

        /*
         * update the cache read creds for this vnode
         */
        if (np->n_rcred)
                crfree(np->n_rcred);
        np->n_rcred = cred;
        crhold(cred);

        do {
            if ((vp->v_flag & VROOT) && vp->v_type == VLNK) {
                    return (nfs_readlinkrpc(vp, uio, cred));
            }
            baddr = NULL;
            switch (vp->v_type) {
            case VREG:
                nfsstats.biocache_reads++;
                lbn = uio->uio_offset / biosize;
                on = uio->uio_offset & (biosize - 1);
                bn = lbn * (biosize / DEV_BSIZE);
                not_readin = 1;

                /*
                 * Start the read ahead(s), as required.
                 */
                if (nfs_numasync > 0 && nmp->nm_readahead > 0) {
                    for (nra = 0; nra < nmp->nm_readahead &&
                        (lbn + 1 + nra) * biosize < np->n_size; nra++) {
                        rabn = (lbn + 1 + nra) * (biosize / DEV_BSIZE);
                        if (!incore(vp, rabn)) {
                            rabp = nfs_getcacheblk(vp, rabn, biosize, p);
                            if (!rabp)
                                return (EINTR);
                            if ((rabp->b_flags & (B_DELWRI | B_DONE)) == 0) {
                                rabp->b_flags |= (B_READ | B_ASYNC);
                                if (nfs_asyncio(rabp, 1)) {
                                    rabp->b_flags |= B_INVAL;
                                    brelse(rabp);
                                }
                            } else
                                brelse(rabp);
                        }
                    }
                }

again:
                bp = nfs_getcacheblk(vp, bn, biosize, p);
                if (!bp)
                        return (EINTR);
                got_buf = 1;
                if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) {
                        bp->b_flags |= B_READ;
                        not_readin = 0;
                        error = nfs_doio(bp, p);
                        if (error) {
                            brelse(bp);
                            return (error);
                        }
                }
                n = ulmin(biosize - on, uio->uio_resid);
                offdiff = np->n_size - uio->uio_offset;
                if (offdiff < (off_t)n)
                        n = (int)offdiff;
                if (not_readin && n > 0) {
                        if (on < bp->b_validoff || (on + n) > bp->b_validend) {
                                bp->b_flags |= B_INVAFTERWRITE;
                                if (bp->b_dirtyend > 0) {
                                    if ((bp->b_flags & B_DELWRI) == 0)
                                        panic("nfsbioread");
                                    if (VOP_BWRITE(bp) == EINTR)
                                        return (EINTR);
                                } else
                                    brelse(bp);
                                goto again;
                        }
                }
                diff = (on >= bp->b_validend) ? 0 : (bp->b_validend - on);
                if (diff < n)
                        n = diff;
                break;
            case VLNK:
                nfsstats.biocache_readlinks++;
                bp = nfs_getcacheblk(vp, 0, NFS_MAXPATHLEN, p);
                if (!bp)
                        return (EINTR);
                if ((bp->b_flags & B_DONE) == 0) {
                        bp->b_flags |= B_READ;
                        error = nfs_doio(bp, p);
                        if (error) {
                                brelse(bp);
                                return (error);
                        }
                }
                n = ulmin(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
                got_buf = 1;
                on = 0;
                break;
            default:
                panic("nfsbioread: type %x unexpected", vp->v_type);
                break;
            }

            if (n > 0) {
                if (!baddr)
                        baddr = bp->b_data;
                error = uiomove(baddr + on, n, uio);
            }

            if (vp->v_type == VLNK)
                n = 0;

            if (got_buf)
                brelse(bp);
        } while (error == 0 && uio->uio_resid > 0 && n > 0);
        return (error);
}

/*
 * Vnode op for write using bio
 */
int
nfs_write(void *v)
{
        struct vop_write_args *ap = v;
        int biosize;
        struct uio *uio = ap->a_uio;
        struct proc *p = uio->uio_procp;
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np = VTONFS(vp);
        struct ucred *cred = ap->a_cred;
        int ioflag = ap->a_ioflag;
        struct buf *bp;
        struct vattr vattr;
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        daddr_t lbn, bn;
        int n, on, error = 0, extended = 0, wrotedta = 0, truncated = 0;
        ssize_t overrun;

#ifdef DIAGNOSTIC
        if (uio->uio_rw != UIO_WRITE)
                panic("nfs_write mode");
        if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
                panic("nfs_write proc");
#endif
        if (vp->v_type != VREG)
                return (EIO);
        if (np->n_flag & NWRITEERR) {
                np->n_flag &= ~NWRITEERR;
                return (np->n_error);
        }
        if ((nmp->nm_flag & (NFSMNT_NFSV3 | NFSMNT_GOTFSINFO)) == NFSMNT_NFSV3)
                (void)nfs_fsinfo(nmp, vp, cred, p);
        if (ioflag & (IO_APPEND | IO_SYNC)) {
                if (np->n_flag & NMODIFIED) {
                        NFS_INVALIDATE_ATTRCACHE(np);
                        error = nfs_vinvalbuf(vp, V_SAVE, cred, p);
                        if (error)
                                return (error);
                }
                if (ioflag & IO_APPEND) {
                        NFS_INVALIDATE_ATTRCACHE(np);
                        error = VOP_GETATTR(vp, &vattr, cred, p);
                        if (error)
                                return (error);
                        uio->uio_offset = np->n_size;
                }
        }
        if (uio->uio_offset < 0)
                return (EINVAL);
        if (uio->uio_resid == 0)
                return (0);

        /* do the filesize rlimit check */
        if ((error = vn_fsizechk(vp, uio, ioflag, &overrun)))
                return (error);

        /*
         * update the cache write creds for this node.
         */
        if (np->n_wcred)
                crfree(np->n_wcred);
        np->n_wcred = cred;
        crhold(cred);

        /*
         * I use nm_rsize, not nm_wsize so that all buffer cache blocks
         * will be the same size within a filesystem. nfs_writerpc will
         * still use nm_wsize when sizing the rpc's.
         */
        biosize = nmp->nm_rsize;
        do {

                /*
                 * XXX make sure we aren't cached in the VM page cache
                 */
                uvm_vnp_uncache(vp);

                nfsstats.biocache_writes++;
                lbn = uio->uio_offset / biosize;
                on = uio->uio_offset & (biosize-1);
                n = ulmin(biosize - on, uio->uio_resid);
                bn = lbn * (biosize / DEV_BSIZE);
again:
                bp = nfs_getcacheblk(vp, bn, biosize, p);
                if (!bp) {
                        error = EINTR;
                        goto out;
                }
                np->n_flag |= NMODIFIED;
                if (uio->uio_offset + n > np->n_size) {
                        np->n_size = uio->uio_offset + n;
                        uvm_vnp_setsize(vp, np->n_size);
                        extended = 1;
                } else if (uio->uio_offset + n < np->n_size)
                        truncated = 1;

                /*
                 * If the new write will leave a contiguous dirty
                 * area, just update the b_dirtyoff and b_dirtyend,
                 * otherwise force a write rpc of the old dirty area.
                 */
                if (bp->b_dirtyend > 0 &&
                    (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
                        bp->b_proc = p;
                        if (VOP_BWRITE(bp) == EINTR) {
                                error = EINTR;
                                goto out;
                        }
                        goto again;
                }

                error = uiomove((char *)bp->b_data + on, n, uio);
                if (error) {
                        bp->b_flags |= B_ERROR;
                        brelse(bp);
                        goto out;
                }
                if (bp->b_dirtyend > 0) {
                        bp->b_dirtyoff = min(on, bp->b_dirtyoff);
                        bp->b_dirtyend = max((on + n), bp->b_dirtyend);
                } else {
                        bp->b_dirtyoff = on;
                        bp->b_dirtyend = on + n;
                }
                if (bp->b_validend == 0 || bp->b_validend < bp->b_dirtyoff ||
                    bp->b_validoff > bp->b_dirtyend) {
                        bp->b_validoff = bp->b_dirtyoff;
                        bp->b_validend = bp->b_dirtyend;
                } else {
                        bp->b_validoff = min(bp->b_validoff, bp->b_dirtyoff);
                        bp->b_validend = max(bp->b_validend, bp->b_dirtyend);
                }

                wrotedta = 1;

                /*
                 * Since this block is being modified, it must be written
                 * again and not just committed.
                 */

                if (NFS_ISV3(vp)) {
                        rw_enter_write(&np->n_commitlock);
                        if (bp->b_flags & B_NEEDCOMMIT) {
                                bp->b_flags &= ~B_NEEDCOMMIT;
                                nfs_del_tobecommitted_range(vp, bp);
                        }
                        nfs_del_committed_range(vp, bp);
                        rw_exit_write(&np->n_commitlock);
                } else 
                        bp->b_flags &= ~B_NEEDCOMMIT;

                if (ioflag & IO_SYNC) {
                        bp->b_proc = p;
                        error = VOP_BWRITE(bp);
                        if (error)
                                goto out;
                } else if ((n + on) == biosize) {
                        bp->b_proc = NULL;
                        bp->b_flags |= B_ASYNC;
                        (void)nfs_writebp(bp, 0);
                } else {
                        bdwrite(bp);
                }
        } while (uio->uio_resid > 0 && n > 0);

/*out: XXX belongs here??? */
        if (wrotedta)
                VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0) |
                    (truncated ? NOTE_TRUNCATE : 0));

out:
        /* correct the result for writes clamped by vn_fsizechk() */
        uio->uio_resid += overrun;

        return (error);
}

/*
 * Get an nfs cache block.
 * Allocate a new one if the block isn't currently in the cache
 * and return the block marked busy. If the calling process is
 * interrupted by a signal for an interruptible mount point, return
 * NULL.
 */
struct buf *
nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct proc *p)
{
        struct buf *bp;
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);

        if (nmp->nm_flag & NFSMNT_INT) {
                bp = getblk(vp, bn, size, PCATCH, INFSLP);
                while (bp == NULL) {
                        if (nfs_sigintr(nmp, NULL, p))
                                return (NULL);
                        bp = getblk(vp, bn, size, 0, SEC_TO_NSEC(2));
                }
        } else
                bp = getblk(vp, bn, size, 0, INFSLP);
        return (bp);
}

/*
 * Flush and invalidate all dirty buffers. If another process is already
 * doing the flush, just wait for completion.
 */
int
nfs_vinvalbuf(struct vnode *vp, int flags, struct ucred *cred, struct proc *p)
{
        struct nfsmount         *nmp= VFSTONFS(vp->v_mount);
        struct nfsnode          *np = VTONFS(vp);
        uint64_t                 stimeo;
        int                      error, sintr;

        stimeo = INFSLP;
        error = sintr = 0;

        if (ISSET(nmp->nm_flag, NFSMNT_INT)) {
                sintr = PCATCH;
                stimeo = SEC_TO_NSEC(2);
        }

        /* First wait for any other process doing a flush to complete. */
        while (np->n_flag & NFLUSHINPROG) {
                np->n_flag |= NFLUSHWANT;
                error = tsleep_nsec(&np->n_flag, PRIBIO|sintr, "nfsvinval",
                    stimeo);
                if (error && sintr && nfs_sigintr(nmp, NULL, p))
                        return (EINTR);
        }

        /* Now, flush as required. */
        np->n_flag |= NFLUSHINPROG;
        error = vinvalbuf(vp, flags, cred, p, sintr, INFSLP);
        while (error) {
                if (sintr && nfs_sigintr(nmp, NULL, p)) {
                        np->n_flag &= ~NFLUSHINPROG;
                        if (np->n_flag & NFLUSHWANT) {
                                np->n_flag &= ~NFLUSHWANT;
                                wakeup(&np->n_flag);
                        }
                        return (EINTR);
                }
                error = vinvalbuf(vp, flags, cred, p, 0, stimeo);
        }
        np->n_flag &= ~(NMODIFIED | NFLUSHINPROG);
        if (np->n_flag & NFLUSHWANT) {
                np->n_flag &= ~NFLUSHWANT;
                wakeup(&np->n_flag);
        }
        return (0);
}

/*
 * Initiate asynchronous I/O. Return an error if no nfsiods are available.
 * This is mainly to avoid queueing async I/O requests when the nfsiods
 * are all hung on a dead server.
 */
int
nfs_asyncio(struct buf *bp, int readahead)
{
        if (nfs_numasync == 0)
                goto out;

        while (nfs_bufqlen > nfs_bufqmax)
                if (readahead)
                        goto out;
                else
                        tsleep_nsec(&nfs_bufqlen, PRIBIO, "nfs_bufq", INFSLP);

        if ((bp->b_flags & B_READ) == 0) {
                bp->b_flags |= B_WRITEINPROG;
        }

        TAILQ_INSERT_TAIL(&nfs_bufq, bp, b_freelist);
        nfs_bufqlen++;

        wakeup_one(&nfs_bufq);
        return (0);

out:
        nfsstats.forcedsync++;
        return (EIO);
}

/*
 * Do an I/O operation to/from a cache block. This may be called
 * synchronously or from an nfsiod.
 */
int
nfs_doio(struct buf *bp, struct proc *p)
{
        struct uio *uiop;
        struct vnode *vp;
        struct nfsnode *np;
        struct nfsmount *nmp;
        int s, error = 0, diff, len, iomode, must_commit = 0;
        struct uio uio;
        struct iovec io;

        vp = bp->b_vp;
        np = VTONFS(vp);
        nmp = VFSTONFS(vp->v_mount);
        uiop = &uio;
        uiop->uio_iov = &io;
        uiop->uio_iovcnt = 1;
        uiop->uio_segflg = UIO_SYSSPACE;
        uiop->uio_procp = p;

        /*
         * Historically, paging was done with physio, but no more.
         */
        if (bp->b_flags & B_PHYS) {
            io.iov_len = uiop->uio_resid = bp->b_bcount;
            /* mapping was done by vmapbuf() */
            io.iov_base = bp->b_data;
            uiop->uio_offset = ((off_t)bp->b_blkno) << DEV_BSHIFT;
            if (bp->b_flags & B_READ) {
                uiop->uio_rw = UIO_READ;
                nfsstats.read_physios++;
                error = nfs_readrpc(vp, uiop);
            } else {
                iomode = NFSV3WRITE_DATASYNC;
                uiop->uio_rw = UIO_WRITE;
                nfsstats.write_physios++;
                error = nfs_writerpc(vp, uiop, &iomode, &must_commit);
            }
            if (error) {
                bp->b_flags |= B_ERROR;
                bp->b_error = error;
            }
        } else if (bp->b_flags & B_READ) {
            io.iov_len = uiop->uio_resid = bp->b_bcount;
            io.iov_base = bp->b_data;
            uiop->uio_rw = UIO_READ;
            switch (vp->v_type) {
            case VREG:
                uiop->uio_offset = ((off_t)bp->b_blkno) << DEV_BSHIFT;
                nfsstats.read_bios++;
                bcstats.pendingreads++;
                bcstats.numreads++;
                error = nfs_readrpc(vp, uiop);
                if (!error) {
                    bp->b_validoff = 0;
                    if (uiop->uio_resid) {
                        /*
                         * If len > 0, there is a hole in the file and
                         * no writes after the hole have been pushed to
                         * the server yet.
                         * Just zero fill the rest of the valid area.
                         */
                        diff = bp->b_bcount - uiop->uio_resid;
                        len = np->n_size - ((((off_t)bp->b_blkno) << DEV_BSHIFT)
                                + diff);
                        if (len > 0) {
                            len = ulmin(len, uiop->uio_resid);
                            memset((char *)bp->b_data + diff, 0, len);
                            bp->b_validend = diff + len;
                        } else
                            bp->b_validend = diff;
                    } else
                        bp->b_validend = bp->b_bcount;
                }
                if (p && (vp->v_flag & VTEXT) &&
                    (timespeccmp(&np->n_mtime, &np->n_vattr.va_mtime, !=))) {
                        uprintf("Process killed due to text file modification\n");
                        psignal(p, SIGKILL);
                }
                break;
            case VLNK:
                uiop->uio_offset = (off_t)0;
                nfsstats.readlink_bios++;
                bcstats.pendingreads++;
                bcstats.numreads++;
                error = nfs_readlinkrpc(vp, uiop, curproc->p_ucred);
                break;
            default:
                panic("nfs_doio:  type %x unexpected", vp->v_type);
                break;
            }
            if (error) {
                bp->b_flags |= B_ERROR;
                bp->b_error = error;
            }
        } else {
            io.iov_len = uiop->uio_resid = bp->b_dirtyend
                - bp->b_dirtyoff;
            uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE
                + bp->b_dirtyoff;
            io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
            uiop->uio_rw = UIO_WRITE;
            nfsstats.write_bios++;
            bcstats.pendingwrites++;
            bcstats.numwrites++;
            if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE)) == B_ASYNC)
                iomode = NFSV3WRITE_UNSTABLE;
            else
                iomode = NFSV3WRITE_FILESYNC;
            bp->b_flags |= B_WRITEINPROG;
            error = nfs_writerpc(vp, uiop, &iomode, &must_commit);

            rw_enter_write(&np->n_commitlock);
            if (!error && iomode == NFSV3WRITE_UNSTABLE) {
                bp->b_flags |= B_NEEDCOMMIT;
                nfs_add_tobecommitted_range(vp, bp);
            } else {
                bp->b_flags &= ~B_NEEDCOMMIT;
                nfs_del_committed_range(vp, bp);
            }
            rw_exit_write(&np->n_commitlock);

            bp->b_flags &= ~B_WRITEINPROG;

            /*
             * For an interrupted write, the buffer is still valid and the
             * write hasn't been pushed to the server yet, so we can't set
             * B_ERROR and report the interruption by setting B_EINTR. For
             * the B_ASYNC case, B_EINTR is not relevant, so the rpc attempt
             * is essentially a noop.
             * For the case of a V3 write rpc not being committed to stable
             * storage, the block is still dirty and requires either a commit
             * rpc or another write rpc with iomode == NFSV3WRITE_FILESYNC
             * before the block is reused. This is indicated by setting the
             * B_DELWRI and B_NEEDCOMMIT flags.
             */
            if (error == EINTR || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
                    s = splbio();
                    buf_dirty(bp);
                    splx(s);

                    if (!(bp->b_flags & B_ASYNC) && error)
                            bp->b_flags |= B_EINTR;
            } else {
                if (error) {
                    bp->b_flags |= B_ERROR;
                    bp->b_error = np->n_error = error;
                    np->n_flag |= NWRITEERR;
                }
                bp->b_dirtyoff = bp->b_dirtyend = 0;
            }
        }
        bp->b_resid = uiop->uio_resid;
        if (must_commit)
                nfs_clearcommit(vp->v_mount);
        s = splbio();
        biodone(bp);
        splx(s);
        return (error);
}