Reset to 3.12.37

10 files changed, 130 insertions, 102 deletions

diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
index 8a50b3c..e15bcbd 100644
--- a/fs/nfsd/nfs4acl.c
+++ b/fs/nfsd/nfs4acl.c
@@ -385,8 +385,10 @@ sort_pacl(struct posix_acl *pacl)
 	 * by uid/gid. */
 	int i, j;
 
-	if (pacl->a_count <= 4)
-		return; /* no users or groups */
+	/* no users or groups */
+	if (!pacl || pacl->a_count <= 4)
+		return;
+
 	i = 1;
 	while (pacl->a_entries[i].e_tag == ACL_USER)
 		i++;
@@ -513,13 +515,12 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
 
 	/*
 	 * ACLs with no ACEs are treated differently in the inheritable
-	 * and effective cases: when there are no inheritable ACEs, we
-	 * set a zero-length default posix acl:
+	 * and effective cases: when there are no inheritable ACEs,
+	 * calls ->set_acl with a NULL ACL structure.
 	 */
-	if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) {
-		pacl = posix_acl_alloc(0, GFP_KERNEL);
-		return pacl ? pacl : ERR_PTR(-ENOMEM);
-	}
+	if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT))
+		return NULL;
+
 	/*
 	 * When there are no effective ACEs, the following will end
 	 * up setting a 3-element effective posix ACL with all
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 7f05cd1..f42bbe5 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -637,9 +637,11 @@ static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc
 
 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
 {
+	int maxtime = max_cb_time(clp->net);
 	struct rpc_timeout	timeparms = {
-		.to_initval	= max_cb_time(clp->net),
+		.to_initval	= maxtime,
 		.to_retries	= 0,
+		.to_maxval	= maxtime,
 	};
 	struct rpc_create_args args = {
 		.net		= clp->net,
@@ -670,7 +672,8 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c
 		clp->cl_cb_session = ses;
 		args.bc_xprt = conn->cb_xprt;
 		args.prognumber = clp->cl_cb_session->se_cb_prog;
-		args.protocol = XPRT_TRANSPORT_BC_TCP;
+		args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
+				XPRT_TRANSPORT_BC;
 		args.authflavor = ses->se_cb_sec.flavor;
 	}
 	/* Create RPC client */
@@ -781,8 +784,12 @@ static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
 {
 	if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
 		rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
-		dprintk("%s slot is busy\n", __func__);
-		return false;
+		/* Race breaker */
+		if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
+			dprintk("%s slot is busy\n", __func__);
+			return false;
+		}
+		rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
 	}
 	return true;
 }
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 419572f..25024d5 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -610,15 +610,6 @@ nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 
 	switch (create->cr_type) {
 	case NF4LNK:
-		/* ugh! we have to null-terminate the linktext, or
-		 * vfs_symlink() will choke.  it is always safe to
-		 * null-terminate by brute force, since at worst we
-		 * will overwrite the first byte of the create namelen
-		 * in the XDR buffer, which has already been extracted
-		 * during XDR decode.
-		 */
-		create->cr_linkname[create->cr_linklen] = 0;
-
 		status = nfsd_symlink(rqstp, &cstate->current_fh,
 				      create->cr_name, create->cr_namelen,
 				      create->cr_linkname, create->cr_linklen,
@@ -1242,7 +1233,8 @@ static bool need_wrongsec_check(struct svc_rqst *rqstp)
 	 */
 	if (argp->opcnt == resp->opcnt)
 		return false;
-
+	if (next->opnum == OP_ILLEGAL)
+		return false;
 	nextd = OPDESC(next);
 	/*
 	 * Rest of 2.6.3.1.1: certain operations will return WRONGSEC
@@ -1349,6 +1341,12 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
 		/* If op is non-idempotent */
 		if (opdesc->op_flags & OP_MODIFIES_SOMETHING) {
 			plen = opdesc->op_rsize_bop(rqstp, op);
+			/*
+			 * If there's still another operation, make sure
+			 * we'll have space to at least encode an error:
+			 */
+			if (resp->opcnt < args->opcnt)
+				plen += COMPOUND_ERR_SLACK_SPACE;
 			op->status = nfsd4_check_resp_size(resp, plen);
 		}
 
@@ -1513,7 +1511,8 @@ static inline u32 nfsd4_setattr_rsize(struct svc_rqst *rqstp, struct nfsd4_op *o
 
 static inline u32 nfsd4_setclientid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
-	return (op_encode_hdr_size + 2 + 1024) * sizeof(__be32);
+	return (op_encode_hdr_size + 2 + XDR_QUADLEN(NFS4_VERIFIER_SIZE)) *
+								sizeof(__be32);
 }
 
 static inline u32 nfsd4_write_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 0874998..0a138e4 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1071,6 +1071,18 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name)
 		return NULL;
 	}
 	clp->cl_name.len = name.len;
+	INIT_LIST_HEAD(&clp->cl_sessions);
+	idr_init(&clp->cl_stateids);
+	atomic_set(&clp->cl_refcount, 0);
+	clp->cl_cb_state = NFSD4_CB_UNKNOWN;
+	INIT_LIST_HEAD(&clp->cl_idhash);
+	INIT_LIST_HEAD(&clp->cl_openowners);
+	INIT_LIST_HEAD(&clp->cl_delegations);
+	INIT_LIST_HEAD(&clp->cl_lru);
+	INIT_LIST_HEAD(&clp->cl_callbacks);
+	INIT_LIST_HEAD(&clp->cl_revoked);
+	spin_lock_init(&clp->cl_lock);
+	rpc_init_wait_queue(&clp->cl_cb_waitq, "Backchannel slot table");
 	return clp;
 }
 
@@ -1088,6 +1100,7 @@ free_client(struct nfs4_client *clp)
 		WARN_ON_ONCE(atomic_read(&ses->se_ref));
 		free_session(ses);
 	}
+	rpc_destroy_wait_queue(&clp->cl_cb_waitq);
 	free_svc_cred(&clp->cl_cred);
 	kfree(clp->cl_name.data);
 	idr_destroy(&clp->cl_stateids);
@@ -1184,15 +1197,14 @@ static int copy_cred(struct svc_cred *target, struct svc_cred *source)
 	return 0;
 }
 
-static long long
+static int
 compare_blob(const struct xdr_netobj *o1, const struct xdr_netobj *o2)
 {
-	long long res;
-
-	res = o1->len - o2->len;
-	if (res)
-		return res;
-	return (long long)memcmp(o1->data, o2->data, o1->len);
+	if (o1->len < o2->len)
+		return -1;
+	if (o1->len > o2->len)
+		return 1;
+	return memcmp(o1->data, o2->data, o1->len);
 }
 
 static int same_name(const char *n1, const char *n2)
@@ -1335,7 +1347,6 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
 	if (clp == NULL)
 		return NULL;
 
-	INIT_LIST_HEAD(&clp->cl_sessions);
 	ret = copy_cred(&clp->cl_cred, &rqstp->rq_cred);
 	if (ret) {
 		spin_lock(&nn->client_lock);
@@ -1343,20 +1354,9 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
 		spin_unlock(&nn->client_lock);
 		return NULL;
 	}
-	idr_init(&clp->cl_stateids);
-	atomic_set(&clp->cl_refcount, 0);
-	clp->cl_cb_state = NFSD4_CB_UNKNOWN;
-	INIT_LIST_HEAD(&clp->cl_idhash);
-	INIT_LIST_HEAD(&clp->cl_openowners);
-	INIT_LIST_HEAD(&clp->cl_delegations);
-	INIT_LIST_HEAD(&clp->cl_lru);
-	INIT_LIST_HEAD(&clp->cl_callbacks);
-	INIT_LIST_HEAD(&clp->cl_revoked);
-	spin_lock_init(&clp->cl_lock);
 	nfsd4_init_callback(&clp->cl_cb_null);
 	clp->cl_time = get_seconds();
 	clear_bit(0, &clp->cl_cb_slot_busy);
-	rpc_init_wait_queue(&clp->cl_cb_waitq, "Backchannel slot table");
 	copy_verf(clp, verf);
 	rpc_copy_addr((struct sockaddr *) &clp->cl_addr, sa);
 	gen_confirm(clp);
@@ -1388,7 +1388,7 @@ add_clp_to_name_tree(struct nfs4_client *new_clp, struct rb_root *root)
 static struct nfs4_client *
 find_clp_in_name_tree(struct xdr_netobj *name, struct rb_root *root)
 {
-	long long cmp;
+	int cmp;
 	struct rb_node *node = root->rb_node;
 	struct nfs4_client *clp;
 
@@ -3695,9 +3695,16 @@ out:
 static __be32
 nfsd4_free_lock_stateid(struct nfs4_ol_stateid *stp)
 {
-	if (check_for_locks(stp->st_file, lockowner(stp->st_stateowner)))
+	struct nfs4_lockowner *lo = lockowner(stp->st_stateowner);
+
+	if (check_for_locks(stp->st_file, lo))
 		return nfserr_locks_held;
-	release_lock_stateid(stp);
+	/*
+	 * Currently there's a 1-1 lock stateid<->lockowner
+	 * correspondance, and we have to delete the lockowner when we
+	 * delete the lock stateid:
+	 */
+	release_lockowner(lo);
 	return nfs_ok;
 }
 
@@ -4141,6 +4148,10 @@ static bool same_lockowner_ino(struct nfs4_lockowner *lo, struct inode *inode, c
 
 	if (!same_owner_str(&lo->lo_owner, owner, clid))
 		return false;
+	if (list_empty(&lo->lo_owner.so_stateids)) {
+		WARN_ON_ONCE(1);
+		return false;
+	}
 	lst = list_first_entry(&lo->lo_owner.so_stateids,
 			       struct nfs4_ol_stateid, st_perstateowner);
 	return lst->st_file->fi_inode == inode;
@@ -5048,7 +5059,6 @@ nfs4_state_destroy_net(struct net *net)
 	int i;
 	struct nfs4_client *clp = NULL;
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
-	struct rb_node *node, *tmp;
 
 	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
 		while (!list_empty(&nn->conf_id_hashtbl[i])) {
@@ -5057,13 +5067,11 @@ nfs4_state_destroy_net(struct net *net)
 		}
 	}
 
-	node = rb_first(&nn->unconf_name_tree);
-	while (node != NULL) {
-		tmp = node;
-		node = rb_next(tmp);
-		clp = rb_entry(tmp, struct nfs4_client, cl_namenode);
-		rb_erase(tmp, &nn->unconf_name_tree);
-		destroy_client(clp);
+	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
+		while (!list_empty(&nn->unconf_id_hashtbl[i])) {
+			clp = list_entry(nn->unconf_id_hashtbl[i].next, struct nfs4_client, cl_idhash);
+			destroy_client(clp);
+		}
 	}
 
 	kfree(nn->sessionid_hashtbl);
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index ecc735e..1c825ae 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -594,7 +594,18 @@ nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create
 		READ_BUF(4);
 		READ32(create->cr_linklen);
 		READ_BUF(create->cr_linklen);
-		SAVEMEM(create->cr_linkname, create->cr_linklen);
+		/*
+		 * The VFS will want a null-terminated string, and
+		 * null-terminating in place isn't safe since this might
+		 * end on a page boundary:
+		 */
+		create->cr_linkname =
+				kmalloc(create->cr_linklen + 1, GFP_KERNEL);
+		if (!create->cr_linkname)
+			return nfserr_jukebox;
+		memcpy(create->cr_linkname, p, create->cr_linklen);
+		create->cr_linkname[create->cr_linklen] = '\0';
+		defer_free(argp, kfree, create->cr_linkname);
 		break;
 	case NF4BLK:
 	case NF4CHR:
@@ -1775,6 +1786,9 @@ static __be32 nfsd4_encode_components_esc(char sep, char *components,
 		}
 		else
 			end++;
+		if (found_esc)
+			end = next;
+
 		str = end;
 	}
 	*pp = p;
@@ -2113,8 +2127,8 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
 	err = vfs_getattr(&path, &stat);
 	if (err)
 		goto out_nfserr;
-	if ((bmval0 & (FATTR4_WORD0_FILES_FREE | FATTR4_WORD0_FILES_TOTAL |
-			FATTR4_WORD0_MAXNAME)) ||
+	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
+			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
 	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
 		       FATTR4_WORD1_SPACE_TOTAL))) {
 		err = vfs_statfs(&path, &statfs);
@@ -2502,6 +2516,8 @@ out_acl:
 			goto out;
 	}
 	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
+		if ((buflen -= 16) < 0)
+			goto out_resource;
 		WRITE32(3);
 		WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD0);
 		WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD1);
@@ -3510,6 +3526,9 @@ nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
 	struct nfsd4_test_stateid_id *stateid, *next;
 	__be32 *p;
 
+	if (nfserr)
+		return nfserr;
+
 	RESERVE_SPACE(4 + (4 * test_stateid->ts_num_ids));
 	*p++ = htonl(test_stateid->ts_num_ids);
 
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index b6af150..6040da8 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -132,13 +132,6 @@ nfsd_reply_cache_alloc(void)
 }
 
 static void
-nfsd_reply_cache_unhash(struct svc_cacherep *rp)
-{
-	hlist_del_init(&rp->c_hash);
-	list_del_init(&rp->c_lru);
-}
-
-static void
 nfsd_reply_cache_free_locked(struct svc_cacherep *rp)
 {
 	if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base) {
@@ -231,13 +224,6 @@ hash_refile(struct svc_cacherep *rp)
 	hlist_add_head(&rp->c_hash, cache_hash + hash_32(rp->c_xid, maskbits));
 }
 
-static inline bool
-nfsd_cache_entry_expired(struct svc_cacherep *rp)
-{
-	return rp->c_state != RC_INPROG &&
-	       time_after(jiffies, rp->c_timestamp + RC_EXPIRE);
-}
-
 /*
  * Walk the LRU list and prune off entries that are older than RC_EXPIRE.
  * Also prune the oldest ones when the total exceeds the max number of entries.
@@ -249,8 +235,14 @@ prune_cache_entries(void)
 	long freed = 0;
 
 	list_for_each_entry_safe(rp, tmp, &lru_head, c_lru) {
-		if (!nfsd_cache_entry_expired(rp) &&
-		    num_drc_entries <= max_drc_entries)
+		/*
+		 * Don't free entries attached to calls that are still
+		 * in-progress, but do keep scanning the list.
+		 */
+		if (rp->c_state == RC_INPROG)
+			continue;
+		if (num_drc_entries <= max_drc_entries &&
+		    time_before(jiffies, rp->c_timestamp + RC_EXPIRE))
 			break;
 		nfsd_reply_cache_free_locked(rp);
 		freed++;
@@ -416,22 +408,8 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
 
 	/*
 	 * Since the common case is a cache miss followed by an insert,
-	 * preallocate an entry. First, try to reuse the first entry on the LRU
-	 * if it works, then go ahead and prune the LRU list.
+	 * preallocate an entry.
 	 */
-	spin_lock(&cache_lock);
-	if (!list_empty(&lru_head)) {
-		rp = list_first_entry(&lru_head, struct svc_cacherep, c_lru);
-		if (nfsd_cache_entry_expired(rp) ||
-		    num_drc_entries >= max_drc_entries) {
-			nfsd_reply_cache_unhash(rp);
-			prune_cache_entries();
-			goto search_cache;
-		}
-	}
-
-	/* No expired ones available, allocate a new one. */
-	spin_unlock(&cache_lock);
 	rp = nfsd_reply_cache_alloc();
 	spin_lock(&cache_lock);
 	if (likely(rp)) {
@@ -439,7 +417,9 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
 		drc_mem_usage += sizeof(*rp);
 	}
 
-search_cache:
+	/* go ahead and prune the cache */
+	prune_cache_entries();
+
 	found = nfsd_cache_search(rqstp, csum);
 	if (found) {
 		if (likely(rp))
@@ -453,15 +433,6 @@ search_cache:
 		goto out;
 	}
 
-	/*
-	 * We're keeping the one we just allocated. Are we now over the
-	 * limit? Prune one off the tip of the LRU in trade for the one we
-	 * just allocated if so.
-	 */
-	if (num_drc_entries >= max_drc_entries)
-		nfsd_reply_cache_free_locked(list_first_entry(&lru_head,
-						struct svc_cacherep, c_lru));
-
 	nfsdstats.rcmisses++;
 	rqstp->rq_cacherep = rp;
 	rp->c_state = RC_INPROG;
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 7f55517..f34d9de 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -699,6 +699,11 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net)
 	if (err != 0 || fd < 0)
 		return -EINVAL;
 
+	if (svc_alien_sock(net, fd)) {
+		printk(KERN_ERR "%s: socket net is different to NFSd's one\n", __func__);
+		return -EINVAL;
+	}
+
 	err = nfsd_create_serv(net);
 	if (err != 0)
 		return err;
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 30f34ab..f417fef 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -282,7 +282,7 @@ void		nfsd_lockd_shutdown(void);
  * reason.
  */
 #define	COMPOUND_SLACK_SPACE		140    /* OP_GETFH */
-#define COMPOUND_ERR_SLACK_SPACE	12     /* OP_SETATTR */
+#define COMPOUND_ERR_SLACK_SPACE	16     /* OP_SETATTR */
 
 #define NFSD_LAUNDROMAT_MINTIMEOUT      1   /* seconds */
 
@@ -328,12 +328,15 @@ void		nfsd_lockd_shutdown(void);
 	(NFSD4_SUPPORTED_ATTRS_WORD2 | FATTR4_WORD2_SUPPATTR_EXCLCREAT)
 
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
-#define NFSD4_2_SUPPORTED_ATTRS_WORD2 \
-	(NFSD4_1_SUPPORTED_ATTRS_WORD2 | FATTR4_WORD2_SECURITY_LABEL)
+#define NFSD4_2_SECURITY_ATTRS		FATTR4_WORD2_SECURITY_LABEL
 #else
-#define NFSD4_2_SUPPORTED_ATTRS_WORD2 0
+#define NFSD4_2_SECURITY_ATTRS		0
 #endif
 
+#define NFSD4_2_SUPPORTED_ATTRS_WORD2 \
+	(NFSD4_1_SUPPORTED_ATTRS_WORD2 | \
+	NFSD4_2_SECURITY_ATTRS)
+
 static inline u32 nfsd_suppattrs0(u32 minorversion)
 {
 	return minorversion ? NFSD4_1_SUPPORTED_ATTRS_WORD0
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 760c85a..4942f43 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -221,7 +221,8 @@ static int nfsd_startup_generic(int nrservs)
 	 */
 	ret = nfsd_racache_init(2*nrservs);
 	if (ret)
-		return ret;
+		goto dec_users;
+
 	ret = nfs4_state_start();
 	if (ret)
 		goto out_racache;
@@ -229,6 +230,8 @@ static int nfsd_startup_generic(int nrservs)
 
 out_racache:
 	nfsd_racache_shutdown();
+dec_users:
+	nfsd_users--;
 	return ret;
 }
 
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 72cb28e..fafac65 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -407,6 +407,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 	umode_t		ftype = 0;
 	__be32		err;
 	int		host_err;
+	bool		get_write_count;
 	int		size_change = 0;
 
 	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
@@ -414,10 +415,18 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 	if (iap->ia_valid & ATTR_SIZE)
 		ftype = S_IFREG;
 
+	/* Callers that do fh_verify should do the fh_want_write: */
+	get_write_count = !fhp->fh_dentry;
+
 	/* Get inode */
 	err = fh_verify(rqstp, fhp, ftype, accmode);
 	if (err)
 		goto out;
+	if (get_write_count) {
+		host_err = fh_want_write(fhp);
+		if (host_err)
+			return nfserrno(host_err);
+	}
 
 	dentry = fhp->fh_dentry;
 	inode = dentry->d_inode;
@@ -500,6 +509,9 @@ set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
 	char *buf = NULL;
 	int error = 0;
 
+	if (!pacl)
+		return vfs_setxattr(dentry, key, NULL, 0, 0);
+
 	buflen = posix_acl_xattr_size(pacl->a_count);
 	buf = kmalloc(buflen, GFP_KERNEL);
 	error = -ENOMEM;