Re: panic: No NCF_TS

From: Kostik Belousov <kostikbel_at_gmail.com>
Date: Mon, 23 Jan 2012 05:05:13 +0200
On Mon, Jan 23, 2012 at 05:36:42AM +0400, Yuri Pankov wrote:
> Seems to be reproducible here running r230467 as the NFS client and
> r230135 as NFS server. NFSv4 not enabled.
> 
> # mount
> [...]
> sirius:/data/distfiles on /usr/ports/distfiles (nfs)
> 
> # /usr/bin/env /usr/bin/fetch -AFpr -S 4682084 -o /usr/ports/distfiles/sqlite-src-3071000.zip http://www.sqlite.org/sqlite-src-3071000.zip
> /usr/ports/distfiles/sqlite-src-3071000.zip   100% of 4572 kB  379 kBps 00m00s
> # rm /usr/ports/distfiles/sqlite-src-3071000.zip
> 
> immediately followed by:
> 
> panic: No NCF_TS
> cpuid = 2
> KDB: enter: panic
> [ thread pid 1603 tid 100494 ]
> Stopped at	kdb_enter+0x3e:	movq	$0,kdb_why
> db> bt
> Tracing pid 1603 tid 100494 td 0xfffffe0089585460
> kdb_enter() at kdb_enter+0x3e
> panic() at panic+0x245
> cache_lookup_times() at cache_lookup_times+0x6b5
> nfs_lookup() at nfs_lookup+0x190
> VOP_LOOKUP_APV() at VOP_LOOKUP_APV+0x8b
> lookup() at lookup+0x7e9
> namei() at namei+0x74c
> kern_statat_vnhook() at kern_statat_vnhook+0x90
> sys_lstat() at sys_lstat+0x30
> amd64_syscall() at amd64_syscall+0x221
> Xfast_syscall() at Xfast_syscall+0xfb
> --- syscall (190, FreeBSD ELF64, sys_lstat), rip = 0x80093ff3c, rsp = 0x7fffffffd8d8, rbp = 0x7fffffffd979 ---
> 

Yes, my bad. I wrote the r230441 with the assumption that filesystems
are consistent in their use of cache_enter_time(). And my net-booting
test box did not catched this, which is at least interesting.

Please try the change below. Actually, it should be enough to only apply
the changes for fs/nfsclient (or nfsclient/ if you use old nfs). If this
does not help, then please try the whole patch.

Even if not needed for correctness, I think vfs_cache.c change could
be made useful by adding KASSERT to it.

commit 9771eb4739170d014fcebfbad07bfed4076c6d85
Author: Konstantin Belousov <kostik_at_pooma.home>
Date:   Mon Jan 23 04:36:08 2012 +0200

    Make NCF_TS mismatch not fatal.
    Consistently use cache_enter_time in nfs clients.

diff --git a/sys/fs/nfsclient/nfs_clvnops.c b/sys/fs/nfsclient/nfs_clvnops.c
index 2747191..2841647 100644
--- a/sys/fs/nfsclient/nfs_clvnops.c
+++ b/sys/fs/nfsclient/nfs_clvnops.c
_at__at_ -1432,7 +1432,7 _at__at_ nfs_mknodrpc(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp,
 	}
 	if (!error) {
 		if ((cnp->cn_flags & MAKEENTRY))
-			cache_enter(dvp, newvp, cnp);
+			cache_enter_time(dvp, newvp, cnp, &vattr.va_ctime);
 		*vpp = newvp;
 	} else if (NFS_ISV4(dvp)) {
 		error = nfscl_maperr(cnp->cn_thread, error, vap->va_uid,
_at__at_ -1591,7 +1591,7 _at__at_ again:
 	}
 	if (!error) {
 		if (cnp->cn_flags & MAKEENTRY)
-			cache_enter(dvp, newvp, cnp);
+			cache_enter_time(dvp, newvp, cnp, &vap->va_ctime);
 		*ap->a_vpp = newvp;
 	} else if (NFS_ISV4(dvp)) {
 		error = nfscl_maperr(cnp->cn_thread, error, vap->va_uid,
_at__at_ -1923,6 +1923,7 _at__at_ nfs_link(struct vop_link_args *ap)
 	struct componentname *cnp = ap->a_cnp;
 	struct nfsnode *np, *tdnp;
 	struct nfsvattr nfsva, dnfsva;
+	struct timespec ts;
 	int error = 0, attrflag, dattrflag;
 
 	if (vp->v_mount != tdvp->v_mount) {
_at__at_ -1966,8 +1967,10 _at__at_ nfs_link(struct vop_link_args *ap)
 	 * must care about lookup caching hit rate, so...
 	 */
 	if (VFSTONFS(vp->v_mount)->nm_negnametimeo != 0 &&
-	    (cnp->cn_flags & MAKEENTRY))
-		cache_enter(tdvp, vp, cnp);
+	    (cnp->cn_flags & MAKEENTRY)) {
+		vfs_timestamp(&ts);
+		cache_enter_time(tdvp, vp, cnp, &ts);
+	}
 	if (error && NFS_ISV4(vp))
 		error = nfscl_maperr(cnp->cn_thread, error, (uid_t)0,
 		    (gid_t)0);
_at__at_ -1987,6 +1990,7 _at__at_ nfs_symlink(struct vop_symlink_args *ap)
 	struct nfsfh *nfhp;
 	struct nfsnode *np = NULL, *dnp;
 	struct vnode *newvp = NULL;
+	struct timespec ts;
 	int error = 0, attrflag, dattrflag, ret;
 
 	vap->va_type = VLNK;
_at__at_ -2030,8 +2034,10 _at__at_ nfs_symlink(struct vop_symlink_args *ap)
 		 * must care about lookup caching hit rate, so...
 		 */
 		if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 &&
-		    (cnp->cn_flags & MAKEENTRY))
-			cache_enter(dvp, newvp, cnp);
+		    (cnp->cn_flags & MAKEENTRY)) {
+			vfs_timestamp(&ts);
+			cache_enter_time(dvp, newvp, cnp, &ts);
+		}
 		*ap->a_vpp = newvp;
 	}
 
_at__at_ -2063,6 +2069,7 _at__at_ nfs_mkdir(struct vop_mkdir_args *ap)
 	struct vattr vattr;
 	struct nfsfh *nfhp;
 	struct nfsvattr nfsva, dnfsva;
+	struct timespec ts;
 	int error = 0, attrflag, dattrflag, ret;
 
 	if ((error = VOP_GETATTR(dvp, &vattr, cnp->cn_cred)) != 0)
_at__at_ -2116,8 +2123,10 _at__at_ nfs_mkdir(struct vop_mkdir_args *ap)
 		 * must care about lookup caching hit rate, so...
 		 */
 		if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 &&
-		    (cnp->cn_flags & MAKEENTRY))
-			cache_enter(dvp, newvp, cnp);
+		    (cnp->cn_flags & MAKEENTRY)) {
+			vfs_timestamp(&ts);
+			cache_enter_time(dvp, newvp, cnp, &ts);
+		}
 		*ap->a_vpp = newvp;
 	}
 	return (error);
diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index c11f25f..647dcac 100644
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
_at__at_ -233,6 +233,24 _at__at_ nc_get_name(struct namecache *ncp)
 	return (ncp_ts->nc_name);
 }
 
+static void
+cache_out_ts(struct namecache *ncp, struct timespec *tsp, int *ticksp)
+{
+
+	if ((ncp->nc_flag & NCF_TS) == 0) {
+		if (tsp != NULL)
+			bzero(tsp, sizeof(*tsp));
+		if (ticksp != NULL)
+			*ticksp = 0;
+		return;
+	}
+
+	if (tsp != NULL)
+		*tsp = ((struct namecache_ts *)ncp)->nc_time;
+	if (ticksp != NULL)
+		*ticksp = ((struct namecache_ts *)ncp)->nc_ticks;
+}
+
 static int	doingcache = 1;		/* 1 => enable the cache */
 SYSCTL_INT(_debug, OID_AUTO, vfscache, CTLFLAG_RW, &doingcache, 0,
     "VFS namecache enabled");
_at__at_ -506,17 +524,7 _at__at_ retry_wlocked:
 			    dvp, cnp->cn_nameptr, *vpp);
 			SDT_PROBE(vfs, namecache, lookup, hit, dvp, "..",
 			    *vpp, 0, 0);
-			if (tsp != NULL) {
-				KASSERT((ncp->nc_flag & NCF_TS) != 0,
-				    ("No NCF_TS"));
-				*tsp = ((struct namecache_ts *)ncp)->nc_time;
-			}
-			if (ticksp != NULL) {
-				KASSERT((ncp->nc_flag & NCF_TS) != 0,
-				    ("No NCF_TS"));
-				*ticksp = ((struct namecache_ts *)ncp)->
-				    nc_ticks;
-			}
+			cache_out_ts(ncp, tsp, ticksp);
 			goto success;
 		}
 	}
_at__at_ -563,14 +571,7 _at__at_ retry_wlocked:
 		    dvp, cnp->cn_nameptr, *vpp, ncp);
 		SDT_PROBE(vfs, namecache, lookup, hit, dvp, nc_get_name(ncp),
 		    *vpp, 0, 0);
-		if (tsp != NULL) {
-			KASSERT((ncp->nc_flag & NCF_TS) != 0, ("No NCF_TS"));
-			*tsp = ((struct namecache_ts *)ncp)->nc_time;
-		}
-		if (ticksp != NULL) {
-			KASSERT((ncp->nc_flag & NCF_TS) != 0, ("No NCF_TS"));
-			*ticksp = ((struct namecache_ts *)ncp)->nc_ticks;
-		}
+		cache_out_ts(ncp, tsp, ticksp);
 		goto success;
 	}
 
_at__at_ -602,14 +603,7 _at__at_ negative_success:
 		cnp->cn_flags |= ISWHITEOUT;
 	SDT_PROBE(vfs, namecache, lookup, hit_negative, dvp, nc_get_name(ncp),
 	    0, 0, 0);
-	if (tsp != NULL) {
-		KASSERT((ncp->nc_flag & NCF_TS) != 0, ("No NCF_TS"));
-		*tsp = ((struct namecache_ts *)ncp)->nc_time;
-	}
-	if (ticksp != NULL) {
-		KASSERT((ncp->nc_flag & NCF_TS) != 0, ("No NCF_TS"));
-		*ticksp = ((struct namecache_ts *)ncp)->nc_ticks;
-	}
+	cache_out_ts(ncp, tsp, ticksp);
 	CACHE_WUNLOCK();
 	return (ENOENT);
 
_at__at_ -797,8 +791,8 _at__at_ cache_enter_time(dvp, vp, cnp, tsp)
 		    n2->nc_nlen == cnp->cn_namelen &&
 		    !bcmp(nc_get_name(n2), cnp->cn_nameptr, n2->nc_nlen)) {
 			if (tsp != NULL) {
-				KASSERT((n2->nc_flag & NCF_TS) != 0,
-				    ("no NCF_TS"));
+				if ((n2->nc_flag & NCF_TS) == 0)
+					continue;
 				n3 = (struct namecache_ts *)n2;
 				n3->nc_time =
 				    ((struct namecache_ts *)ncp)->nc_time;
diff --git a/sys/nfsclient/nfs_vnops.c b/sys/nfsclient/nfs_vnops.c
index a39b29b..2fc4d2c 100644
--- a/sys/nfsclient/nfs_vnops.c
+++ b/sys/nfsclient/nfs_vnops.c
_at__at_ -1531,7 +1531,7 _at__at_ nfsmout:
 			vput(newvp);
 	} else {
 		if (cnp->cn_flags & MAKEENTRY)
-			cache_enter(dvp, newvp, cnp);
+			cache_enter_time(dvp, newvp, cnp, &vap->va_ctime);
 		*vpp = newvp;
 	}
 	mtx_lock(&(VTONFS(dvp))->n_mtx);
_at__at_ -1671,7 +1671,7 _at__at_ nfsmout:
 	}
 	if (!error) {
 		if (cnp->cn_flags & MAKEENTRY)
-			cache_enter(dvp, newvp, cnp);
+			cache_enter_time(dvp, newvp, cnp, &vap->va_ctime);
 		*ap->a_vpp = newvp;
 	}
 	mtx_lock(&(VTONFS(dvp))->n_mtx);

Received on Mon Jan 23 2012 - 02:05:19 UTC

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