1 files changed, 37 insertions, 9 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index ea9f6ca8f30f..23a78a742b61 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -789,16 +789,17 @@ again:
 		goto out;
 	}
 
+	nfs_set_verifier(dentry, dir_verifier);
 	inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
 	alias = d_splice_alias(inode, dentry);
 	d_lookup_done(dentry);
 	if (alias) {
 		if (IS_ERR(alias))
 			goto out;
+		nfs_set_verifier(alias, dir_verifier);
 		dput(dentry);
 		dentry = alias;
 	}
-	nfs_set_verifier(dentry, dir_verifier);
 	trace_nfs_readdir_lookup(d_inode(parent), dentry, 0);
 out:
 	dput(dentry);
@@ -1514,6 +1515,15 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry,
 		return 0;
 	if (!nfs_dentry_verify_change(dir, dentry))
 		return 0;
+
+	/*
+	 * If we have a directory delegation then we don't need to revalidate
+	 * the directory. The delegation will either get recalled or we will
+	 * receive a notification when it changes.
+	 */
+	if (nfs_have_directory_delegation(dir))
+		return 0;
+
 	/* Revalidate nfsi->cache_change_attribute before we declare a match */
 	if (nfs_mapping_need_revalidate_inode(dir)) {
 		if (rcu_walk)
@@ -1894,13 +1904,15 @@ static int nfs_dentry_delete(const struct dentry *dentry)
 }
 
 /* Ensure that we revalidate inode->i_nlink */
-static void nfs_drop_nlink(struct inode *inode)
+static void nfs_drop_nlink(struct inode *inode, unsigned long gencount)
 {
+	struct nfs_inode *nfsi = NFS_I(inode);
+
 	spin_lock(&inode->i_lock);
 	/* drop the inode if we're reasonably sure this is the last link */
-	if (inode->i_nlink > 0)
+	if (inode->i_nlink > 0 && gencount == nfsi->attr_gencount)
 		drop_nlink(inode);
-	NFS_I(inode)->attr_gencount = nfs_inc_attr_generation_counter();
+	nfsi->attr_gencount = nfs_inc_attr_generation_counter();
 	nfs_set_cache_invalid(
 		inode, NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME |
 			       NFS_INO_INVALID_NLINK);
@@ -1914,8 +1926,9 @@ static void nfs_drop_nlink(struct inode *inode)
 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
 {
 	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+		unsigned long gencount = READ_ONCE(NFS_I(inode)->attr_gencount);
 		nfs_complete_unlink(dentry, inode);
-		nfs_drop_nlink(inode);
+		nfs_drop_nlink(inode, gencount);
 	}
 	iput(inode);
 }
@@ -1991,13 +2004,14 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in
 	nfs_lookup_advise_force_readdirplus(dir, flags);
 
 no_entry:
+	nfs_set_verifier(dentry, dir_verifier);
 	res = d_splice_alias(inode, dentry);
 	if (res != NULL) {
 		if (IS_ERR(res))
 			goto out;
+		nfs_set_verifier(res, dir_verifier);
 		dentry = res;
 	}
-	nfs_set_verifier(dentry, dir_verifier);
 out:
 	trace_nfs_lookup_exit(dir, dentry, flags, PTR_ERR_OR_ZERO(res));
 	nfs_free_fattr(fattr);
@@ -2139,12 +2153,12 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
 		d_drop(dentry);
 		switch (err) {
 		case -ENOENT:
-			d_splice_alias(NULL, dentry);
 			if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE))
 				dir_verifier = inode_peek_iversion_raw(dir);
 			else
 				dir_verifier = nfs_save_change_attribute(dir);
 			nfs_set_verifier(dentry, dir_verifier);
+			d_splice_alias(NULL, dentry);
 			break;
 		case -EISDIR:
 		case -ENOTDIR:
@@ -2203,6 +2217,13 @@ no_open:
 EXPORT_SYMBOL_GPL(nfs_atomic_open);
 
 static int
+nfs_lookup_revalidate_delegated_parent(struct inode *dir, struct dentry *dentry,
+				       struct inode *inode)
+{
+	return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
+}
+
+static int
 nfs4_lookup_revalidate(struct inode *dir, const struct qstr *name,
 		       struct dentry *dentry, unsigned int flags)
 {
@@ -2229,6 +2250,9 @@ nfs4_lookup_revalidate(struct inode *dir, const struct qstr *name,
 	if (nfs_verifier_is_delegated(dentry))
 		return nfs_lookup_revalidate_delegated(dir, dentry, inode);
 
+	if (nfs_have_directory_delegation(dir))
+		return nfs_lookup_revalidate_delegated_parent(dir, dentry, inode);
+
 	/* NFS only supports OPEN on regular files */
 	if (!S_ISREG(inode->i_mode))
 		goto full_reval;
@@ -2507,9 +2531,11 @@ static int nfs_safe_remove(struct dentry *dentry)
 
 	trace_nfs_remove_enter(dir, dentry);
 	if (inode != NULL) {
+		unsigned long gencount = READ_ONCE(NFS_I(inode)->attr_gencount);
+
 		error = NFS_PROTO(dir)->remove(dir, dentry);
 		if (error == 0)
-			nfs_drop_nlink(inode);
+			nfs_drop_nlink(inode, gencount);
 	} else
 		error = NFS_PROTO(dir)->remove(dir, dentry);
 	if (error == -ENOENT)
@@ -2709,6 +2735,7 @@ int nfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 {
 	struct inode *old_inode = d_inode(old_dentry);
 	struct inode *new_inode = d_inode(new_dentry);
+	unsigned long new_gencount = 0;
 	struct dentry *dentry = NULL;
 	struct rpc_task *task;
 	bool must_unblock = false;
@@ -2761,6 +2788,7 @@ int nfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		} else {
 			block_revalidate(new_dentry);
 			must_unblock = true;
+			new_gencount = NFS_I(new_inode)->attr_gencount;
 			spin_unlock(&new_dentry->d_lock);
 		}
 
@@ -2800,7 +2828,7 @@ out:
 			new_dir, new_dentry, error);
 	if (!error) {
 		if (new_inode != NULL)
-			nfs_drop_nlink(new_inode);
+			nfs_drop_nlink(new_inode, new_gencount);
 		/*
 		 * The d_move() should be here instead of in an async RPC completion
 		 * handler because we need the proper locks to move the dentry.  If