Remove the magic way of configuring NFS backed swap.

This code dates back to the very first diskless support on FreeBSD,
back when swapon(8) couldn't simply be run on a NFS backed file.

Suggested replacement command sequence on the client:

        dd if=/dev/zero of=/swapfile bs=1k count=1 oseek=100000
        swapon /swapfile
        rm -f /swapfile

For whatever value of 100000 you want.

4 files changed, 1 insertions, 243 deletions

diff --git a/sys/nfsclient/bootp_subr.c b/sys/nfsclient/bootp_subr.c
index 61c02c0..740242b 100644
--- a/sys/nfsclient/bootp_subr.c
+++ b/sys/nfsclient/bootp_subr.c
@@ -155,17 +155,14 @@ struct bootpc_globalcontext {
 	struct bootpc_ifcontext *lastinterface;
 	u_int32_t xid;
 	int gotrootpath;
-	int gotswappath;
 	int gotgw;
 	int ifnum;
 	int secs;
 	int starttime;
 	struct bootp_packet reply;
 	int replylen;
-	struct bootpc_ifcontext *setswapfs;
 	struct bootpc_ifcontext *setrootfs;
 	struct bootpc_ifcontext *sethostname;
-	char lookup_path[24];
 	struct bootpc_tagcontext tmptag;
 	struct bootpc_tagcontext tag;
 };
@@ -220,9 +217,6 @@ SYSCTL_STRING(_kern, OID_AUTO, bootp_cookie, CTLFLAG_RD,
 /* mountd RPC */
 static int	md_mount(struct sockaddr_in *mdsin, char *path, u_char *fhp,
 		    int *fhsizep, struct nfs_args *args, struct thread *td);
-static int	md_lookup_swap(struct sockaddr_in *mdsin, char *path,
-		    u_char *fhp, int *fhsizep, struct nfs_args *args,
-		    struct thread *td);
 static int	setfs(struct sockaddr_in *addr, char *path, char *p);
 static int	getdec(char **ptr);
 static char	*substr(char *a, char *b);
@@ -1495,9 +1489,6 @@ bootpc_decode_reply(struct nfsv3_diskless *nd, struct bootpc_ifcontext *ifctx,
 	ifctx->myaddr.sin_addr = ifctx->reply.yiaddr;
 
 	ip = ntohl(ifctx->myaddr.sin_addr.s_addr);
-	snprintf(gctx->lookup_path, sizeof(gctx->lookup_path),
-		 "swap.%d.%d.%d.%d",
-		 ip >> 24, (ip >> 16) & 255, (ip >> 8) & 255, ip & 255);
 
 	printf("%s at ", ifctx->ireq.ifr_name);
 	print_sin_addr(&ifctx->myaddr);
@@ -1576,45 +1567,6 @@ bootpc_decode_reply(struct nfsv3_diskless *nd, struct bootpc_ifcontext *ifctx,
 	}
 
 	p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
-		       TAG_SWAP);
-	if (p != NULL) {
-		if (gctx->setswapfs != NULL) {
-			printf("swapfs %s (ignored) ", p);
-		} else 	if (setfs(&nd->swap_saddr,
-				  nd->swap_hostnam, p)) {
-			gctx->gotswappath = 1;
-			gctx->setswapfs = ifctx;
-			printf("swapfs %s ", p);
-
-			p = bootpc_tag(&gctx->tag, &ifctx->reply,
-				       ifctx->replylen,
-				       TAG_SWAPOPTS);
-			if (p != NULL) {
-				/* swap mount options */
-				mountopts(&nd->swap_args, p);
-				printf("swapopts %s ", p);
-			}
-
-			p = bootpc_tag(&gctx->tag, &ifctx->reply,
-				       ifctx->replylen,
-				       TAG_SWAPSIZE);
-			if (p != NULL) {
-				int swaplen;
-				if (gctx->tag.taglen != 4)
-					panic("bootpc: "
-					      "Expected 4 bytes for swaplen, "
-					      "not %d bytes",
-					      gctx->tag.taglen);
-				bcopy(p, &swaplen, 4);
-				nd->swap_nblks = ntohl(swaplen);
-				printf("swapsize %d KB ",
-				       nd->swap_nblks);
-			}
-		} else
-			panic("Failed to set swapfs to %s", p);
-	}
-
-	p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
 		       TAG_HOSTNAME);
 	if (p != NULL) {
 		if (gctx->tag.taglen >= MAXHOSTNAMELEN)
@@ -1762,14 +1714,10 @@ bootpc_init(void)
 
 	mountopts(&nd->root_args, NULL);
 
-	mountopts(&nd->swap_args, NULL);
-
 	for (ifctx = gctx->interfaces; ifctx != NULL; ifctx = ifctx->next)
 		if (bootpc_ifctx_isresolved(ifctx) != 0)
 			bootpc_decode_reply(nd, ifctx, gctx);
 
-	if (gctx->gotswappath == 0)
-		nd->swap_nblks = 0;
 #ifdef BOOTP_NFSROOT
 	if (gctx->gotrootpath == 0)
 		panic("bootpc: No root path offered");
@@ -1802,24 +1750,6 @@ bootpc_init(void)
 		if (error != 0)
 			panic("nfs_boot: mountd root, error=%d", error);
 
-		if (gctx->gotswappath != 0) {
-
-			error = md_mount(&nd->swap_saddr,
-					 nd->swap_hostnam,
-					 nd->swap_fh, &nd->swap_fhsize,
-					 &nd->swap_args, td);
-			if (error != 0)
-				panic("nfs_boot: mountd swap, error=%d",
-				      error);
-
-			error = md_lookup_swap(&nd->swap_saddr,
-					       gctx->lookup_path,
-					       nd->swap_fh, &nd->swap_fhsize,
-					       &nd->swap_args, td);
-			if (error != 0)
-				panic("nfs_boot: lookup swap, error=%d",
-				      error);
-		}
 		nfs_diskless_valid = 3;
 	}
 
@@ -1936,96 +1866,3 @@ out:
 	m_freem(m);
 	return error;
 }
-
-static int
-md_lookup_swap(struct sockaddr_in *mdsin, char *path, u_char *fhp, int *fhsizep,
-    struct nfs_args *args, struct thread *td)
-{
-	struct mbuf *m;
-	int error;
-	int size = -1;
-	int attribs_present;
-	int status;
-	union {
-		u_int32_t v2[17];
-		u_int32_t v3[21];
-	} fattribs;
-
-	m = m_get(M_TRYWAIT, MT_DATA);
-	if (m == NULL)
-	  	return ENOBUFS;
-
-	if ((args->flags & NFSMNT_NFSV3) != 0) {
-		*mtod(m, u_int32_t *) = txdr_unsigned(*fhsizep);
-		bcopy(fhp, mtod(m, u_char *) + sizeof(u_int32_t), *fhsizep);
-		m->m_len = *fhsizep + sizeof(u_int32_t);
-	} else {
-		bcopy(fhp, mtod(m, u_char *), NFSX_V2FH);
-		m->m_len = NFSX_V2FH;
-	}
-
-	m->m_next = xdr_string_encode(path, strlen(path));
-	if (m->m_next == NULL) {
-		error = ENOBUFS;
-		goto out;
-	}
-
-	/* Do RPC to nfsd. */
-	if ((args->flags & NFSMNT_NFSV3) != 0)
-		error = krpc_call(mdsin, NFS_PROG, NFS_VER3,
-				  NFSPROC_LOOKUP, &m, NULL, td);
-	else
-		error = krpc_call(mdsin, NFS_PROG, NFS_VER2,
-				  NFSV2PROC_LOOKUP, &m, NULL, td);
-	if (error != 0)
-		return error;	/* message already freed */
-
-	if (xdr_int_decode(&m, &status) != 0)
-		goto bad;
-	if (status != 0) {
-		error = ENOENT;
-		goto out;
-	}
-
-	if ((args->flags & NFSMNT_NFSV3) != 0) {
-		if (xdr_int_decode(&m, fhsizep) != 0 ||
-		    *fhsizep > NFSX_V3FHMAX ||
-		    *fhsizep <= 0)
-			goto bad;
-	} else
-		*fhsizep = NFSX_V2FH;
-
-	if (xdr_opaque_decode(&m, fhp, *fhsizep) != 0)
-		goto bad;
-
-	if ((args->flags & NFSMNT_NFSV3) != 0) {
-		if (xdr_int_decode(&m, &attribs_present) != 0)
-			goto bad;
-		if (attribs_present != 0) {
-			if (xdr_opaque_decode(&m, (u_char *) &fattribs.v3,
-					      sizeof(u_int32_t) * 21) != 0)
-				goto bad;
-			size = fxdr_unsigned(u_int32_t, fattribs.v3[6]);
-		}
-	} else {
-		if (xdr_opaque_decode(&m,(u_char *) &fattribs.v2,
-				      sizeof(u_int32_t) * 17) != 0)
-			goto bad;
-		size = fxdr_unsigned(u_int32_t, fattribs.v2[5]);
-	}
-
-	if (nfsv3_diskless.swap_nblks == 0 && size != -1) {
-		nfsv3_diskless.swap_nblks = size / 1024;
-		printf("md_lookup_swap: Swap size is %d KB\n",
-		       nfsv3_diskless.swap_nblks);
-	}
-
-	goto out;
-
-bad:
-	error = EBADRPC;
-
-out:
-	m_freem(m);
-	return error;
-}
diff --git a/sys/nfsclient/nfs_diskless.c b/sys/nfsclient/nfs_diskless.c
index 4fb45a6..dc847de 100644
--- a/sys/nfsclient/nfs_diskless.c
+++ b/sys/nfsclient/nfs_diskless.c
@@ -129,8 +129,6 @@ match_done:
 	/* set up gateway */
 	inaddr_to_sockaddr("boot.netif.gateway", &nd->mygateway);
 
-	/* XXX set up swap? */
-
 	/* set up root mount */
 	nd->root_args.rsize = 8192;		/* XXX tunable? */
 	nd->root_args.wsize = 8192;
diff --git a/sys/nfsclient/nfs_vfsops.c b/sys/nfsclient/nfs_vfsops.c
index 51c7a0e..6976012 100644
--- a/sys/nfsclient/nfs_vfsops.c
+++ b/sys/nfsclient/nfs_vfsops.c
@@ -141,13 +141,6 @@ SYSCTL_OPAQUE(_vfs_nfs, OID_AUTO, diskless_rootaddr, CTLFLAG_RD,
 	&nfsv3_diskless.root_saddr, sizeof nfsv3_diskless.root_saddr,
 	"%Ssockaddr_in", "");
 
-SYSCTL_STRING(_vfs_nfs, OID_AUTO, diskless_swappath, CTLFLAG_RD,
-	nfsv3_diskless.swap_hostnam, 0, "");
-
-SYSCTL_OPAQUE(_vfs_nfs, OID_AUTO, diskless_swapaddr, CTLFLAG_RD,
-	&nfsv3_diskless.swap_saddr, sizeof nfsv3_diskless.swap_saddr,
-	"%Ssockaddr_in","");
-
 
 void		nfsargs_ntoh(struct nfs_args *);
 static int	nfs_mountdiskless(char *, char *, int,
@@ -204,15 +197,6 @@ nfs_convert_diskless(void)
 		sizeof(struct ifaliasreq));
 	bcopy(&nfs_diskless.mygateway, &nfsv3_diskless.mygateway,
 		sizeof(struct sockaddr_in));
-	nfs_convert_oargs(&nfsv3_diskless.swap_args,&nfs_diskless.swap_args);
-	nfsv3_diskless.swap_fhsize = NFSX_V2FH;
-	bcopy(nfs_diskless.swap_fh, nfsv3_diskless.swap_fh, NFSX_V2FH);
-	bcopy(&nfs_diskless.swap_saddr,&nfsv3_diskless.swap_saddr,
-		sizeof(struct sockaddr_in));
-	bcopy(nfs_diskless.swap_hostnam, nfsv3_diskless.swap_hostnam, MNAMELEN);
-	nfsv3_diskless.swap_nblks = nfs_diskless.swap_nblks;
-	bcopy(&nfs_diskless.swap_ucred, &nfsv3_diskless.swap_ucred,
-		sizeof(struct ucred));
 	nfs_convert_oargs(&nfsv3_diskless.root_args,&nfs_diskless.root_args);
 	nfsv3_diskless.root_fhsize = NFSX_V2FH;
 	bcopy(nfs_diskless.root_fh, nfsv3_diskless.root_fh, NFSX_V2FH);
@@ -385,7 +369,6 @@ nfsmout:
 int
 nfs_mountroot(struct mount *mp, struct thread *td)
 {
-	struct mount  *swap_mp;
 	struct nfsv3_diskless *nd = &nfsv3_diskless;
 	struct socket *so;
 	struct vnode *vp;
@@ -409,17 +392,6 @@ nfs_mountroot(struct mount *mp, struct thread *td)
 	 */
 	splnet();
 
-#ifdef notyet
-	/* Set up swap credentials. */
-	proc0.p_ucred->cr_uid = ntohl(nd->swap_ucred.cr_uid);
-	proc0.p_ucred->cr_gid = ntohl(nd->swap_ucred.cr_gid);
-	if ((proc0.p_ucred->cr_ngroups = ntohs(nd->swap_ucred.cr_ngroups)) >
-		NGROUPS)
-		proc0.p_ucred->cr_ngroups = NGROUPS;
-	for (i = 0; i < proc0.p_ucred->cr_ngroups; i++)
-	    proc0.p_ucred->cr_groups[i] = ntohl(nd->swap_ucred.cr_groups[i]);
-#endif
-
 	/*
 	 * Do enough of ifconfig(8) so that the critical net interface can
 	 * talk to the server.
@@ -488,41 +460,6 @@ nfs_mountroot(struct mount *mp, struct thread *td)
 		return (error);
 	}
 
-	swap_mp = NULL;
-	if (nd->swap_nblks) {
-
-		/* Convert to DEV_BSIZE instead of Kilobyte */
-		nd->swap_nblks *= 2;
-
-		/*
-		 * Create a fake mount point just for the swap vnode so that the
-		 * swap file can be on a different server from the rootfs.
-		 */
-		nd->swap_args.fh = nd->swap_fh;
-		nd->swap_args.fhsize = nd->swap_fhsize;
-		l = ntohl(nd->swap_saddr.sin_addr.s_addr);
-		snprintf(buf, sizeof(buf), "%ld.%ld.%ld.%ld:%s",
-			(l >> 24) & 0xff, (l >> 16) & 0xff,
-			(l >>  8) & 0xff, (l >>  0) & 0xff, nd->swap_hostnam);
-		printf("NFS SWAP: %s\n", buf);
-		if ((error = nfs_mountdiskless(buf, "/swap", 0,
-		    &nd->swap_saddr, &nd->swap_args, td, &vp, &swap_mp)) != 0)
-			return (error);
-		vfs_unbusy(swap_mp, td);
-
-		VTONFS(vp)->n_size = VTONFS(vp)->n_vattr.va_size =
-				nd->swap_nblks * DEV_BSIZE ;
-		/*
-		 * Since the swap file is not the root dir of a filesystem,
-		 * hack it to a regular file.
-		 */
-		vp->v_type = VREG;
-		vp->v_vflag = 0;
-		vp->v_iflag = 0;
-		VREF(vp);
-		swaponvp(td, vp, NODEV, nd->swap_nblks);
-	}
-
 	mp->mnt_flag |= MNT_ROOTFS;
 	mp->mnt_vnodecovered = NULLVP;
 	rootvp = vp;
diff --git a/sys/nfsclient/nfsdiskless.h b/sys/nfsclient/nfsdiskless.h
index 4a189a2..5e00b81 100644
--- a/sys/nfsclient/nfsdiskless.h
+++ b/sys/nfsclient/nfsdiskless.h
@@ -46,8 +46,7 @@
  * and to do a partial ifconfig(8) and route(8) so that the critical net
  * interface can communicate with the server.
  * The primary bootstrap is expected to fill in the appropriate fields before
- * starting the kernel. Whether or not the swap area is nfs mounted is
- * determined by the value in swdevt[0]. (equal to NODEV --> swap over nfs)
+ * starting the kernel.
  * Currently only works for AF_INET protocols.
  * NB: All fields are stored in net byte order to avoid hassles with
  * client/server byte ordering differences.
@@ -64,13 +63,6 @@
 struct nfsv3_diskless {
 	struct ifaliasreq myif;			/* Default interface */
 	struct sockaddr_in mygateway;		/* Default gateway */
-	struct nfs_args	swap_args;		/* Mount args for swap file */
-	int		swap_fhsize;		/* Size of file handle */
-	u_char		swap_fh[NFSX_V3FHMAX];	/* Swap file's file handle */
-	struct sockaddr_in swap_saddr;		/* Address of swap server */
-	char		swap_hostnam[MNAMELEN];	/* Host name for mount pt */
-	int		swap_nblks;		/* Size of server swap file */
-	struct ucred	swap_ucred;		/* Swap credentials */
 	struct nfs_args	root_args;		/* Mount args for root fs */
 	int		root_fhsize;		/* Size of root file handle */
 	u_char		root_fh[NFSX_V3FHMAX];	/* File handle of root dir */
@@ -106,12 +98,6 @@ struct onfs_args {
 struct nfs_diskless {
 	struct ifaliasreq myif;			/* Default interface */
 	struct sockaddr_in mygateway;		/* Default gateway */
-	struct onfs_args swap_args;		/* Mount args for swap file */
-	u_char		swap_fh[NFSX_V2FH];	/* Swap file's file handle */
-	struct sockaddr_in swap_saddr;		/* Address of swap server */
-	char		swap_hostnam[MNAMELEN];	/* Host name for mount pt */
-	int		swap_nblks;		/* Size of server swap file */
-	struct ucred	swap_ucred;		/* Swap credentials */
 	struct onfs_args root_args;		/* Mount args for root fs */
 	u_char		root_fh[NFSX_V2FH];	/* File handle of root dir */
 	struct sockaddr_in root_saddr;		/* Address of root server */