nfs_vnops.c

早期freebsd实现

 * - make nfs_bmap() essentially a no-op that does no translation
 * - do nfs_strategy() by faking physical I/O with nfs_readrpc/nfs_writerpc
 *   after mapping the physical addresses into Kernel Virtual space in the
 *   nfsiobuf area.
 *   (Maybe I could use the process's page mapping, but I was concerned that
 *    Kernel Write might not be enabled and also figured copyout() would do
 *    a lot more work than bcopy() and also it currently happens in the
 *    context of the swapper process (2).
 */
int
nfs_bmap(ap)
	struct vop_bmap_args /* {
		struct vnode *a_vp;
		daddr_t  a_bn;
		struct vnode **a_vpp;
		daddr_t *a_bnp;
		int *a_runp;
	} */ *ap;
{
	register struct vnode *vp = ap->a_vp;

	if (ap->a_vpp != NULL)
		*ap->a_vpp = vp;
	if (ap->a_bnp != NULL)
		*ap->a_bnp = ap->a_bn * btodb(vp->v_mount->mnt_stat.f_iosize);
	return (0);
}

/*
 * Strategy routine.
 * For async requests when nfsiod(s) are running, queue the request by
 * calling nfs_asyncio(), otherwise just all nfs_doio() to do the
 * request.
 */
int
nfs_strategy(ap)
	struct vop_strategy_args *ap;
{
	register struct buf *bp = ap->a_bp;
	struct ucred *cr;
	struct proc *p;
	int error = 0;

	if (bp->b_flags & B_PHYS)
		panic("nfs physio");
	if (bp->b_flags & B_ASYNC)
		p = (struct proc *)0;
	else
		p = curproc;	/* XXX */
	if (bp->b_flags & B_READ)
		cr = bp->b_rcred;
	else
		cr = bp->b_wcred;
	/*
	 * If the op is asynchronous and an i/o daemon is waiting
	 * queue the request, wake it up and wait for completion
	 * otherwise just do it ourselves.
	 */
	if ((bp->b_flags & B_ASYNC) == 0 ||
		nfs_asyncio(bp, NOCRED))
		error = nfs_doio(bp, cr, p);
	return (error);
}

/*
 * Mmap a file
 *
 * NB Currently unsupported.
 */
/* ARGSUSED */
int
nfs_mmap(ap)
	struct vop_mmap_args /* {
		struct vnode *a_vp;
		int  a_fflags;
		struct ucred *a_cred;
		struct proc *a_p;
	} */ *ap;
{

	return (EINVAL);
}

/*
 * Flush all the blocks associated with a vnode.
 * 	Walk through the buffer pool and push any dirty pages
 *	associated with the vnode.
 */
/* ARGSUSED */
int
nfs_fsync(ap)
	struct vop_fsync_args /* {
		struct vnodeop_desc *a_desc;
		struct vnode * a_vp;
		struct ucred * a_cred;
		int  a_waitfor;
		struct proc * a_p;
	} */ *ap;
{
	register struct vnode *vp = ap->a_vp;
	register struct nfsnode *np = VTONFS(vp);
	register struct buf *bp;
	struct buf *nbp;
	struct nfsmount *nmp;
	int s, error = 0, slptimeo = 0, slpflag = 0;

	nmp = VFSTONFS(vp->v_mount);
	if (nmp->nm_flag & NFSMNT_INT)
		slpflag = PCATCH;
loop:
	s = splbio();
	for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) {
		nbp = bp->b_vnbufs.le_next;
		if (bp->b_flags & B_BUSY) {
			if (ap->a_waitfor != MNT_WAIT)
				continue;
			bp->b_flags |= B_WANTED;
			error = tsleep((caddr_t)bp, slpflag | (PRIBIO + 1),
				"nfsfsync", slptimeo);
			splx(s);
			if (error) {
			    if (nfs_sigintr(nmp, (struct nfsreq *)0, ap->a_p))
				return (EINTR);
			    if (slpflag == PCATCH) {
				slpflag = 0;
				slptimeo = 2 * hz;
			    }
			}
			goto loop;
		}
		if ((bp->b_flags & B_DELWRI) == 0)
			panic("nfs_fsync: not dirty");
		bremfree(bp);
		bp->b_flags |= B_BUSY;
		splx(s);
		bp->b_flags |= B_ASYNC;
		VOP_BWRITE(bp);
		goto loop;
	}
	splx(s);
	if (ap->a_waitfor == MNT_WAIT) {
		while (vp->v_numoutput) {
			vp->v_flag |= VBWAIT;
			error = tsleep((caddr_t)&vp->v_numoutput,
				slpflag | (PRIBIO + 1), "nfsfsync", slptimeo);
			if (error) {
			    if (nfs_sigintr(nmp, (struct nfsreq *)0, ap->a_p))
				return (EINTR);
			    if (slpflag == PCATCH) {
				slpflag = 0;
				slptimeo = 2 * hz;
			    }
			}
		}
		if (vp->v_dirtyblkhd.lh_first) {
#ifdef DIAGNOSTIC
			vprint("nfs_fsync: dirty", vp);
#endif
			goto loop;
		}
	}
	if (np->n_flag & NWRITEERR) {
		error = np->n_error;
		np->n_flag &= ~NWRITEERR;
	}
	return (error);
}

/*
 * Return POSIX pathconf information applicable to nfs.
 *
 * Currently the NFS protocol does not support getting such
 * information from the remote server.
 */
/* ARGSUSED */
nfs_pathconf(ap)
	struct vop_pathconf_args /* {
		struct vnode *a_vp;
		int a_name;
		int *a_retval;
	} */ *ap;
{

	return (EINVAL);
}

/*
 * NFS advisory byte-level locks.
 * Currently unsupported.
 */
int
nfs_advlock(ap)
	struct vop_advlock_args /* {
		struct vnode *a_vp;
		caddr_t  a_id;
		int  a_op;
		struct flock *a_fl;
		int  a_flags;
	} */ *ap;
{

	return (EOPNOTSUPP);
}

/*
 * Print out the contents of an nfsnode.
 */
int
nfs_print(ap)
	struct vop_print_args /* {
		struct vnode *a_vp;
	} */ *ap;
{
	register struct vnode *vp = ap->a_vp;
	register struct nfsnode *np = VTONFS(vp);

	printf("tag VT_NFS, fileid %d fsid 0x%x",
		np->n_vattr.va_fileid, np->n_vattr.va_fsid);
#ifdef FIFO
	if (vp->v_type == VFIFO)
		fifo_printinfo(vp);
#endif /* FIFO */
	printf("\n");
}

/*
 * NFS directory offset lookup.
 * Currently unsupported.
 */
int
nfs_blkatoff(ap)
	struct vop_blkatoff_args /* {
		struct vnode *a_vp;
		off_t a_offset;
		char **a_res;
		struct buf **a_bpp;
	} */ *ap;
{

	return (EOPNOTSUPP);
}

/*
 * NFS flat namespace allocation.
 * Currently unsupported.
 */
int
nfs_valloc(ap)
	struct vop_valloc_args /* {
		struct vnode *a_pvp;
		int a_mode;
		struct ucred *a_cred;
		struct vnode **a_vpp;
	} */ *ap;
{

	return (EOPNOTSUPP);
}

/*
 * NFS flat namespace free.
 * Currently unsupported.
 */
int
nfs_vfree(ap)
	struct vop_vfree_args /* {
		struct vnode *a_pvp;
		ino_t a_ino;
		int a_mode;
	} */ *ap;
{

	return (EOPNOTSUPP);
}

/*
 * NFS file truncation.
 */
int
nfs_truncate(ap)
	struct vop_truncate_args /* {
		struct vnode *a_vp;
		off_t a_length;
		int a_flags;
		struct ucred *a_cred;
		struct proc *a_p;
	} */ *ap;
{

	/* Use nfs_setattr */
	printf("nfs_truncate: need to implement!!");
	return (EOPNOTSUPP);
}

/*
 * NFS update.
 */
int
nfs_update(ap)
	struct vop_update_args /* {
		struct vnode *a_vp;
		struct timeval *a_ta;
		struct timeval *a_tm;
		int a_waitfor;
	} */ *ap;
{

	/* Use nfs_setattr */
	printf("nfs_update: need to implement!!");
	return (EOPNOTSUPP);
}

/*
 * nfs special file access vnode op.
 * Essentially just get vattr and then imitate iaccess() since the device is
 * local to the client.
 */
int
nfsspec_access(ap)
	struct vop_access_args /* {
		struct vnode *a_vp;
		int  a_mode;
		struct ucred *a_cred;
		struct proc *a_p;
	} */ *ap;
{
	register struct vattr *vap;
	register gid_t *gp;
	register struct ucred *cred = ap->a_cred;
	mode_t mode = ap->a_mode;
	struct vattr vattr;
	register int i;
	int error;

	/*
	 * If you're the super-user,
	 * you always get access.
	 */
	if (cred->cr_uid == 0)
		return (0);
	vap = &vattr;
	if (error = VOP_GETATTR(ap->a_vp, vap, cred, ap->a_p))
		return (error);
	/*
	 * Access check is based on only one of owner, group, public.
	 * If not owner, then check group. If not a member of the
	 * group, then check public access.
	 */
	if (cred->cr_uid != vap->va_uid) {
		mode >>= 3;
		gp = cred->cr_groups;
		for (i = 0; i < cred->cr_ngroups; i++, gp++)
			if (vap->va_gid == *gp)
				goto found;
		mode >>= 3;
found:
		;
	}
	return ((vap->va_mode & mode) == mode ? 0 : EACCES);
}

/*
 * Read wrapper for special devices.
 */
int
nfsspec_read(ap)
	struct vop_read_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int  a_ioflag;
		struct ucred *a_cred;
	} */ *ap;
{
	register struct nfsnode *np = VTONFS(ap->a_vp);

	/*
	 * Set access flag.
	 */
	np->n_flag |= NACC;
	np->n_atim = time;
	return (VOCALL(spec_vnodeop_p, VOFFSET(vop_read), ap));
}

/*
 * Write wrapper for special devices.
 */
int
nfsspec_write(ap)
	struct vop_write_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int  a_ioflag;
		struct ucred *a_cred;
	} */ *ap;
{
	register struct nfsnode *np = VTONFS(ap->a_vp);

	/*
	 * Set update flag.
	 */
	np->n_flag |= NUPD;
	np->n_mtim = time;
	return (VOCALL(spec_vnodeop_p, VOFFSET(vop_write), ap));
}

/*
 * Close wrapper for special devices.
 *
 * Update the times on the nfsnode then do device close.
 */
int
nfsspec_close(ap)
	struct vop_close_args /* {
		struct vnode *a_vp;
		int  a_fflag;
		struct ucred *a_cred;
		struct proc *a_p;
	} */ *ap;
{
	register struct vnode *vp = ap->a_vp;
	register struct nfsnode *np = VTONFS(vp);
	struct vattr vattr;

	if (np->n_flag & (NACC | NUPD)) {
		np->n_flag |= NCHG;
		if (vp->v_usecount == 1 &&
		    (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
			VATTR_NULL(&vattr);
			if (np->n_flag & NACC) {
				vattr.va_atime.ts_sec = np->n_atim.tv_sec;
				vattr.va_atime.ts_nsec =
				    np->n_atim.tv_usec * 1000;
			}
			if (np->n_flag & NUPD) {
				vattr.va_mtime.ts_sec = np->n_mtim.tv_sec;
				vattr.va_mtime.ts_nsec =
				    np->n_mtim.tv_usec * 1000;
			}
			(void)VOP_SETATTR(vp, &vattr, ap->a_cred, ap->a_p);
		}
	}
	return (VOCALL(spec_vnodeop_p, VOFFSET(vop_close), ap));
}

#ifdef FIFO
/*
 * Read wrapper for fifos.
 */
int
nfsfifo_read(ap)
	struct vop_read_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int  a_ioflag;
		struct ucred *a_cred;
	} */ *ap;
{
	extern int (**fifo_vnodeop_p)();
	register struct nfsnode *np = VTONFS(ap->a_vp);

	/*
	 * Set access flag.
	 */
	np->n_flag |= NACC;
	np->n_atim = time;
	return (VOCALL(fifo_vnodeop_p, VOFFSET(vop_read), ap));
}

/*
 * Write wrapper for fifos.
 */
int
nfsfifo_write(ap)
	struct vop_write_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int  a_ioflag;
		struct ucred *a_cred;
	} */ *ap;
{
	extern int (**fifo_vnodeop_p)();
	register struct nfsnode *np = VTONFS(ap->a_vp);

	/*
	 * Set update flag.
	 */
	np->n_flag |= NUPD;
	np->n_mtim = time;
	return (VOCALL(fifo_vnodeop_p, VOFFSET(vop_write), ap));
}

/*
 * Close wrapper for fifos.
 *
 * Update the times on the nfsnode then do fifo close.
 */
int
nfsfifo_close(ap)
	struct vop_close_args /* {
		struct vnode *a_vp;
		int  a_fflag;