git: 44d99af3c545 - stable/12 - nfscl: return delegations in the NFS VOP_RECLAIM()

Rick Macklem rmacklem at FreeBSD.org
Wed May 12 02:37:38 UTC 2021


The branch stable/12 has been updated by rmacklem:

URL: https://cgit.FreeBSD.org/src/commit/?id=44d99af3c545398c5bbc01b20c611fe63ccdad76

commit 44d99af3c545398c5bbc01b20c611fe63ccdad76
Author:     Rick Macklem <rmacklem at FreeBSD.org>
AuthorDate: 2021-04-26 00:57:55 +0000
Commit:     Rick Macklem <rmacklem at FreeBSD.org>
CommitDate: 2021-05-12 02:32:12 +0000

    nfscl: return delegations in the NFS VOP_RECLAIM()
    
    After a vnode is recycled it can no longer be
    acquired via vfs_hash_get() and, as such,
    a delegation for the vnode cannot be recalled.
    
    In the unlikely event that a delegation still
    exists when the vnode is being recycled, return
    the delegation since it will no longer be
    recallable.
    
    Until you have this patch in your NFSv4 client,
    you should consider avoiding the use of delegations.
    
    (cherry picked from commit aad780464fad1e32c97316515a4044d661413a6b)
---
 sys/fs/nfs/nfs_var.h           |  1 +
 sys/fs/nfsclient/nfs_clnode.c  | 10 ++++++++-
 sys/fs/nfsclient/nfs_clstate.c | 49 ++++++++++++++++++++++++++++++++++--------
 3 files changed, 50 insertions(+), 10 deletions(-)

diff --git a/sys/fs/nfs/nfs_var.h b/sys/fs/nfs/nfs_var.h
index bee66d15b016..0f656601e531 100644
--- a/sys/fs/nfs/nfs_var.h
+++ b/sys/fs/nfs/nfs_var.h
@@ -578,6 +578,7 @@ void nfscl_lockinit(struct nfsv4lock *);
 void nfscl_lockexcl(struct nfsv4lock *, void *);
 void nfscl_lockunlock(struct nfsv4lock *);
 void nfscl_lockderef(struct nfsv4lock *);
+void nfscl_delegreturnvp(vnode_t, NFSPROC_T *);
 void nfscl_docb(struct nfsrv_descript *, NFSPROC_T *);
 void nfscl_releasealllocks(struct nfsclclient *, vnode_t, NFSPROC_T *, void *,
     int);
diff --git a/sys/fs/nfsclient/nfs_clnode.c b/sys/fs/nfsclient/nfs_clnode.c
index f41cb8749020..cdebf9c56631 100644
--- a/sys/fs/nfsclient/nfs_clnode.c
+++ b/sys/fs/nfsclient/nfs_clnode.c
@@ -303,7 +303,7 @@ ncl_reclaim(struct vop_reclaim_args *ap)
 	 */
 	vnode_destroy_vobject(vp);
 
-	if (NFS_ISV4(vp) && vp->v_type == VREG)
+	if (NFS_ISV4(vp) && vp->v_type == VREG) {
 		/*
 		 * We can now safely close any remaining NFSv4 Opens for
 		 * this file. Most opens will have already been closed by
@@ -311,6 +311,14 @@ ncl_reclaim(struct vop_reclaim_args *ap)
 		 * called, so we need to do it again here.
 		 */
 		(void) nfsrpc_close(vp, 1, ap->a_td);
+		/*
+		 * It it unlikely a delegation will still exist, but
+		 * if one does, it must be returned before calling
+		 * vfs_hash_remove(), since it cannot be recalled once the
+		 * nfs node is no longer available.
+		 */
+		nfscl_delegreturnvp(vp, td);
+	}
 
 	vfs_hash_remove(vp);
 
diff --git a/sys/fs/nfsclient/nfs_clstate.c b/sys/fs/nfsclient/nfs_clstate.c
index 03c046c36ccc..5d2641e1f4b0 100644
--- a/sys/fs/nfsclient/nfs_clstate.c
+++ b/sys/fs/nfsclient/nfs_clstate.c
@@ -148,7 +148,8 @@ static int nfscl_trylock(struct nfsmount *, vnode_t , u_int8_t *,
     struct ucred *, NFSPROC_T *);
 static int nfsrpc_reopen(struct nfsmount *, u_int8_t *, int, u_int32_t,
     struct nfsclopen *, struct nfscldeleg **, struct ucred *, NFSPROC_T *);
-static void nfscl_freedeleg(struct nfscldeleghead *, struct nfscldeleg *);
+static void nfscl_freedeleg(struct nfscldeleghead *, struct nfscldeleg *,
+    bool);
 static int nfscl_errmap(struct nfsrv_descript *, u_int32_t);
 static void nfscl_cleanup_common(struct nfsclclient *, u_int8_t *);
 static int nfscl_recalldeleg(struct nfsclclient *, struct nfsmount *,
@@ -1610,12 +1611,13 @@ nfscl_cleandeleg(struct nfscldeleg *dp)
  * Free a delegation.
  */
 static void
-nfscl_freedeleg(struct nfscldeleghead *hdp, struct nfscldeleg *dp)
+nfscl_freedeleg(struct nfscldeleghead *hdp, struct nfscldeleg *dp, bool freeit)
 {
 
 	TAILQ_REMOVE(hdp, dp, nfsdl_list);
 	LIST_REMOVE(dp, nfsdl_hash);
-	free(dp, M_NFSCLDELEG);
+	if (freeit)
+		free(dp, M_NFSCLDELEG);
 	nfsstatsv1.cldelegates--;
 	nfscl_delegcnt--;
 }
@@ -1713,7 +1715,7 @@ nfscl_expireclient(struct nfsclclient *clp, struct nfsmount *nmp,
 		printf("nfsv4 expired locks lost\n");
 	    }
 	    nfscl_cleandeleg(dp);
-	    nfscl_freedeleg(&clp->nfsc_deleg, dp);
+	    nfscl_freedeleg(&clp->nfsc_deleg, dp, true);
 	    dp = ndp;
 	}
 	if (!TAILQ_EMPTY(&clp->nfsc_deleg))
@@ -2230,7 +2232,7 @@ nfscl_recover(struct nfsclclient *clp, struct ucred *cred, NFSPROC_T *p)
 		     * away. Ouch!!
 		     */
 		    nfscl_cleandeleg(dp);
-		    nfscl_freedeleg(&clp->nfsc_deleg, dp);
+		    nfscl_freedeleg(&clp->nfsc_deleg, dp, true);
 		} else {
 		    LIST_INSERT_HEAD(&extra_open, nop, nfso_list);
 		}
@@ -3247,11 +3249,40 @@ nfscl_delegreturnall(struct nfsclclient *clp, NFSPROC_T *p)
 	TAILQ_FOREACH_SAFE(dp, &clp->nfsc_deleg, nfsdl_list, ndp) {
 		nfscl_cleandeleg(dp);
 		(void) nfscl_trydelegreturn(dp, cred, clp->nfsc_nmp, p);
-		nfscl_freedeleg(&clp->nfsc_deleg, dp);
+		nfscl_freedeleg(&clp->nfsc_deleg, dp, true);
 	}
 	NFSFREECRED(cred);
 }
 
+/*
+ * Return any delegation for this vp.
+ */
+void
+nfscl_delegreturnvp(vnode_t vp, NFSPROC_T *p)
+{
+	struct nfsclclient *clp;
+	struct nfscldeleg *dp;
+	struct ucred *cred;
+	struct nfsnode *np;
+
+	np = VTONFS(vp);
+	cred = newnfs_getcred();
+	NFSLOCKCLSTATE();
+	clp = VFSTONFS(vp->v_mount)->nm_clp;
+	dp = nfscl_finddeleg(clp, np->n_fhp->nfh_fh,
+	    np->n_fhp->nfh_len);
+	if (dp != NULL) {
+		nfscl_cleandeleg(dp);
+		nfscl_freedeleg(&clp->nfsc_deleg, dp, false);
+		NFSUNLOCKCLSTATE();
+		newnfs_copycred(&dp->nfsdl_cred, cred);
+		nfscl_trydelegreturn(dp, cred, clp->nfsc_nmp, p);
+		free(dp, M_NFSCLDELEG);
+	} else
+		NFSUNLOCKCLSTATE();
+	NFSFREECRED(cred);
+}
+
 /*
  * Do a callback RPC.
  */
@@ -4478,7 +4509,7 @@ nfscl_removedeleg(vnode_t vp, NFSPROC_T *p, nfsv4stateid_t *stp)
 		    *stp = dp->nfsdl_stateid;
 		    retcnt = 1;
 		    nfscl_cleandeleg(dp);
-		    nfscl_freedeleg(&clp->nfsc_deleg, dp);
+		    nfscl_freedeleg(&clp->nfsc_deleg, dp, true);
 		}
 		if (igotlock)
 		    nfsv4_unlock(&clp->nfsc_lock, 0);
@@ -4578,7 +4609,7 @@ nfscl_renamedeleg(vnode_t fvp, nfsv4stateid_t *fstp, int *gotfdp, vnode_t tvp,
 		    retcnt++;
 		    *gotfdp = 1;
 		    nfscl_cleandeleg(dp);
-		    nfscl_freedeleg(&clp->nfsc_deleg, dp);
+		    nfscl_freedeleg(&clp->nfsc_deleg, dp, true);
 		}
 		if (igotlock) {
 		    nfsv4_unlock(&clp->nfsc_lock, 0);
@@ -4614,7 +4645,7 @@ nfscl_renamedeleg(vnode_t fvp, nfsv4stateid_t *fstp, int *gotfdp, vnode_t tvp,
 			retcnt++;
 			*gottdp = 1;
 			nfscl_cleandeleg(dp);
-			nfscl_freedeleg(&clp->nfsc_deleg, dp);
+			nfscl_freedeleg(&clp->nfsc_deleg, dp, true);
 		    }
 		}
 		NFSUNLOCKCLSTATE();


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