From 6a9301d933d5e1505bd93b4348d16986ecd617f0 Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Sun, 21 Feb 2010 23:40:43 -0800
Subject: [PATCH] kernel - NFS - Add the 'cache' flag to enable swapcache on a
 NFS mount

* The current round of swapcache work doesn't propagate the cache flag
  across mount points so NFS needs a cache mount flag.
---
 sbin/mount_nfs/mount_nfs.c |  6 +++++-
 sys/vfs/nfs/nfs.h          |  2 +-
 sys/vfs/nfs/nfs_vnops.c    | 13 +++++++++++--
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/sbin/mount_nfs/mount_nfs.c b/sbin/mount_nfs/mount_nfs.c
index 51a3ee8a46..b2d79bdb43 100644
--- a/sbin/mount_nfs/mount_nfs.c
+++ b/sbin/mount_nfs/mount_nfs.c
@@ -76,7 +76,7 @@
 #define ALTF_KERB	0x10
 #define ALTF_NFSV3	0x20
 #define ALTF_RDIRPLUS	0x40
-#define	ALTF_UNUSED080	0x80
+#define	ALTF_CACHE	0x80
 #define ALTF_RESVPORT	0x100
 #define ALTF_SEQPACKET	0x200
 #define ALTF_UNUSED400	0x400
@@ -114,6 +114,7 @@ struct mntopt mopts[] = {
 	{ "acregmax=", 0, ALTF_ACREGMAX, 1 },
 	{ "acdirmin=", 0, ALTF_ACDIRMIN, 1 },
 	{ "acdirmax=", 0, ALTF_ACDIRMAX, 1 },
+	{ "cache", 0, ALTF_CACHE, 1 },
 	MOPT_NULL
 };
 
@@ -249,6 +250,9 @@ set_flags(int* altflags, int* nfsflags, int dir)
 	F(ACREGMAX);
 	F(ACDIRMIN);
 	F(ACDIRMAX);
+#ifdef NFSMNT_CACHE
+	F(CACHE);
+#endif
 
 #undef F
 #undef F2
diff --git a/sys/vfs/nfs/nfs.h b/sys/vfs/nfs/nfs.h
index 5e7102199e..d0fa2c5284 100644
--- a/sys/vfs/nfs/nfs.h
+++ b/sys/vfs/nfs/nfs.h
@@ -165,7 +165,7 @@ struct nfs_args {
 #define	NFSMNT_NFSV3		0x00000200  /* Use NFS Version 3 protocol */
 #define	NFSMNT_KERB		0x00000400  /* Use Kerberos authentication */
 #define	NFSMNT_DUMBTIMR		0x00000800  /* Don't estimate rtt dynamically */
-#define	NFSMNT_UNUSED1000	0x00001000  /* set lease term (nqnfs) */
+#define	NFSMNT_CACHE		0x00001000  /* enable swapcache */
 #define	NFSMNT_READAHEAD	0x00002000  /* set read ahead */
 #define	NFSMNT_DEADTHRESH	0x00004000  /* set dead server retry thresh */
 #define	NFSMNT_RESVPORT		0x00008000  /* Allocate a reserved port */
diff --git a/sys/vfs/nfs/nfs_vnops.c b/sys/vfs/nfs/nfs_vnops.c
index dcd47e4c78..3b5685da82 100644
--- a/sys/vfs/nfs/nfs_vnops.c
+++ b/sys/vfs/nfs/nfs_vnops.c
@@ -643,12 +643,14 @@ nfs_getattr(struct vop_getattr_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsnode *np = VTONFS(vp);
+	struct nfsmount *nmp;
 	int error = 0;
 	thread_t td = curthread;
 	struct nfsm_info info;
 
 	info.mrep = NULL;
 	info.v3 = NFS_ISV3(vp);
+	nmp = VFSTONFS(vp->v_mount);
 	
 	/*
 	 * Update local times for special files.
@@ -659,13 +661,13 @@ nfs_getattr(struct vop_getattr_args *ap)
 	 * First look in the cache.
 	 */
 	if (nfs_getattrcache(vp, ap->a_vap) == 0)
-		return (0);
+		goto done;
 
 	if (info.v3 && nfsaccess_cache_timeout > 0) {
 		nfsstats.accesscache_misses++;
 		nfs3_access_otw(vp, NFSV3ACCESS_ALL, td, nfs_vpcred(vp, ND_CHECK));
 		if (nfs_getattrcache(vp, ap->a_vap) == 0)
-			return (0);
+			goto done;
 	}
 
 	nfsstats.rpccnt[NFSPROC_GETATTR]++;
@@ -678,6 +680,13 @@ nfs_getattr(struct vop_getattr_args *ap)
 	}
 	m_freem(info.mrep);
 	info.mrep = NULL;
+done:
+	/*
+	 * NFS doesn't support chflags flags.  If the nfs mount was
+	 * made -o cache set the UF_CACHE bit for swapcache.
+	 */
+	if ((nmp->nm_flag & NFSMNT_CACHE) && (vp->v_flag & VROOT))
+		ap->a_vap->va_flags |= UF_CACHE;
 nfsmout:
 	return (error);
 }
-- 
2.11.4.GIT