NFS client bugfixes for Linux 3.14

Highlights:
 
 - Fix several races in nfs_revalidate_mapping
 - NFSv4.1 slot leakage in the pNFS files driver
 - Stable fix for a slot leak in nfs40_sequence_done
 - Don't reject NFSv4 servers that support ACLs with only ALLOW aces
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Merge tag 'nfs-for-3.14-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights:

   - Fix several races in nfs_revalidate_mapping
   - NFSv4.1 slot leakage in the pNFS files driver
   - Stable fix for a slot leak in nfs40_sequence_done
   - Don't reject NFSv4 servers that support ACLs with only ALLOW aces"

* tag 'nfs-for-3.14-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  nfs: initialize the ACL support bits to zero.
  NFSv4.1: Cleanup
  NFSv4.1: Clean up nfs41_sequence_done
  NFSv4: Fix a slot leak in nfs40_sequence_done
  NFSv4.1 free slot before resending I/O to MDS
  nfs: add memory barriers around NFS_INO_INVALID_DATA and NFS_INO_INVALIDATING
  NFS: Fix races in nfs_revalidate_mapping
  sunrpc: turn warn_gssd() log message into a dprintk()
  NFS: fix the handling of NFS_INO_INVALID_DATA flag in nfs_revalidate_mapping
  nfs: handle servers that support only ALLOW ACE type.

fs/nfs/dir.c

@@ -274,6 +274,15 @@ out_eof:
 	return -EBADCOOKIE;
 }
 
+static bool
+nfs_readdir_inode_mapping_valid(struct nfs_inode *nfsi)
+{
+	if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
+		return false;
+	smp_rmb();
+	return !test_bit(NFS_INO_INVALIDATING, &nfsi->flags);
+}
+
 static
 int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
 {
@@ -287,8 +296,8 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des
 			struct nfs_open_dir_context *ctx = desc->file->private_data;
 
 			new_pos = desc->current_index + i;
-			if (ctx->attr_gencount != nfsi->attr_gencount
-			    || (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))) {
+			if (ctx->attr_gencount != nfsi->attr_gencount ||
+			    !nfs_readdir_inode_mapping_valid(nfsi)) {
 				ctx->duped = 0;
 				ctx->attr_gencount = nfsi->attr_gencount;
 			} else if (new_pos < desc->ctx->pos) {

fs/nfs/inode.c

@@ -977,11 +977,11 @@ static int nfs_invalidate_mapping(struct inode *inode, struct address_space *map
 		if (ret < 0)
 			return ret;
 	}
+	if (S_ISDIR(inode->i_mode)) {
 		spin_lock(&inode->i_lock);
-	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
-	if (S_ISDIR(inode->i_mode))
 		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
 		spin_unlock(&inode->i_lock);
+	}
 	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
 	nfs_fscache_wait_on_invalidate(inode);
 
@@ -1008,6 +1008,7 @@ static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
 int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
+	unsigned long *bitlock = &nfsi->flags;
 	int ret = 0;
 
 	/* swapfiles are not supposed to be shared. */
@@ -1019,12 +1020,46 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
 		if (ret < 0)
 			goto out;
 	}
-	if (nfsi->cache_validity & NFS_INO_INVALID_DATA) {
+
+	/*
+	 * We must clear NFS_INO_INVALID_DATA first to ensure that
+	 * invalidations that come in while we're shooting down the mappings
+	 * are respected. But, that leaves a race window where one revalidator
+	 * can clear the flag, and then another checks it before the mapping
+	 * gets invalidated. Fix that by serializing access to this part of
+	 * the function.
+	 *
+	 * At the same time, we need to allow other tasks to see whether we
+	 * might be in the middle of invalidating the pages, so we only set
+	 * the bit lock here if it looks like we're going to be doing that.
+	 */
+	for (;;) {
+		ret = wait_on_bit(bitlock, NFS_INO_INVALIDATING,
+				  nfs_wait_bit_killable, TASK_KILLABLE);
+		if (ret)
+			goto out;
+		spin_lock(&inode->i_lock);
+		if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
+			spin_unlock(&inode->i_lock);
+			continue;
+		}
+		if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
+			break;
+		spin_unlock(&inode->i_lock);
+		goto out;
+	}
+
+	set_bit(NFS_INO_INVALIDATING, bitlock);
+	smp_wmb();
+	nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
+	spin_unlock(&inode->i_lock);
 	trace_nfs_invalidate_mapping_enter(inode);
 	ret = nfs_invalidate_mapping(inode, mapping);
 	trace_nfs_invalidate_mapping_exit(inode, ret);
-	}
 
+	clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
+	smp_mb__after_clear_bit();
+	wake_up_bit(bitlock, NFS_INO_INVALIDATING);
 out:
 	return ret;
 }

fs/nfs/nfs4_fs.h

@@ -270,6 +270,7 @@ static inline struct nfs4_session *nfs4_get_session(const struct nfs_server *ser
 extern int nfs41_setup_sequence(struct nfs4_session *session,
 		struct nfs4_sequence_args *args, struct nfs4_sequence_res *res,
 		struct rpc_task *task);
+extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *);
 extern int nfs4_proc_create_session(struct nfs_client *, struct rpc_cred *);
 extern int nfs4_proc_destroy_session(struct nfs4_session *, struct rpc_cred *);
 extern int nfs4_proc_get_lease_time(struct nfs_client *clp,

fs/nfs/nfs4client.c

@@ -372,10 +372,7 @@ struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
 	__set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
 
-	error = -EINVAL;
-	if (gssd_running(clp->cl_net))
-		error = nfs_create_rpc_client(clp, timeparms,
-					      RPC_AUTH_GSS_KRB5I);
+	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_GSS_KRB5I);
 	if (error == -EINVAL)
 		error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX);
 	if (error < 0)

fs/nfs/nfs4filelayout.c

@@ -335,8 +335,10 @@ static void filelayout_read_call_done(struct rpc_task *task, void *data)
 	dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
 
 	if (test_bit(NFS_IOHDR_REDO, &rdata->header->flags) &&
-	    task->tk_status == 0)
+	    task->tk_status == 0) {
+		nfs41_sequence_done(task, &rdata->res.seq_res);
 		return;
+	}
 
 	/* Note this may cause RPC to be resent */
 	rdata->header->mds_ops->rpc_call_done(task, data);
@@ -442,8 +444,10 @@ static void filelayout_write_call_done(struct rpc_task *task, void *data)
 	struct nfs_write_data *wdata = data;
 
 	if (test_bit(NFS_IOHDR_REDO, &wdata->header->flags) &&
-	    task->tk_status == 0)
+	    task->tk_status == 0) {
+		nfs41_sequence_done(task, &wdata->res.seq_res);
 		return;
+	}
 
 	/* Note this may cause RPC to be resent */
 	wdata->header->mds_ops->rpc_call_done(task, data);

fs/nfs/nfs4proc.c

@@ -539,7 +539,7 @@ static int nfs40_sequence_done(struct rpc_task *task,
 	struct nfs4_slot *slot = res->sr_slot;
 	struct nfs4_slot_table *tbl;
 
-	if (!RPC_WAS_SENT(task))
+	if (slot == NULL)
 		goto out;
 
 	tbl = slot->table;
@@ -559,15 +559,10 @@ static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
 {
 	struct nfs4_session *session;
 	struct nfs4_slot_table *tbl;
+	struct nfs4_slot *slot = res->sr_slot;
 	bool send_new_highest_used_slotid = false;
 
-	if (!res->sr_slot) {
-		/* just wake up the next guy waiting since
-		 * we may have not consumed a slot after all */
-		dprintk("%s: No slot\n", __func__);
-		return;
-	}
-	tbl = res->sr_slot->table;
+	tbl = slot->table;
 	session = tbl->session;
 
 	spin_lock(&tbl->slot_tbl_lock);
@@ -577,11 +572,11 @@ static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
 	if (tbl->highest_used_slotid > tbl->target_highest_slotid)
 		send_new_highest_used_slotid = true;
 
-	if (nfs41_wake_and_assign_slot(tbl, res->sr_slot)) {
+	if (nfs41_wake_and_assign_slot(tbl, slot)) {
 		send_new_highest_used_slotid = false;
 		goto out_unlock;
 	}
-	nfs4_free_slot(tbl, res->sr_slot);
+	nfs4_free_slot(tbl, slot);
 
 	if (tbl->highest_used_slotid != NFS4_NO_SLOT)
 		send_new_highest_used_slotid = false;
@@ -592,19 +587,20 @@ out_unlock:
 		nfs41_server_notify_highest_slotid_update(session->clp);
 }
 
-static int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *res)
+int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *res)
 {
 	struct nfs4_session *session;
-	struct nfs4_slot *slot;
+	struct nfs4_slot *slot = res->sr_slot;
 	struct nfs_client *clp;
 	bool interrupted = false;
 	int ret = 1;
 
+	if (slot == NULL)
+		goto out_noaction;
 	/* don't increment the sequence number if the task wasn't sent */
 	if (!RPC_WAS_SENT(task))
 		goto out;
 
-	slot = res->sr_slot;
 	session = slot->table->session;
 
 	if (slot->interrupted) {
@@ -679,6 +675,7 @@ out:
 	/* The session may be reset by one of the error handlers. */
 	dprintk("%s: Error %d free the slot \n", __func__, res->sr_status);
 	nfs41_sequence_free_slot(res);
+out_noaction:
 	return ret;
 retry_nowait:
 	if (rpc_restart_call_prepare(task)) {
@@ -692,6 +689,7 @@ out_retry:
 	rpc_delay(task, NFS4_POLL_RETRY_MAX);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(nfs41_sequence_done);
 
 static int nfs4_sequence_done(struct rpc_task *task,
 			       struct nfs4_sequence_res *res)
@@ -2744,7 +2742,8 @@ static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *f
 				NFS_CAP_OWNER_GROUP|NFS_CAP_ATIME|
 				NFS_CAP_CTIME|NFS_CAP_MTIME|
 				NFS_CAP_SECURITY_LABEL);
-		if (res.attr_bitmask[0] & FATTR4_WORD0_ACL)
+		if (res.attr_bitmask[0] & FATTR4_WORD0_ACL &&
+				res.acl_bitmask & ACL4_SUPPORT_ALLOW_ACL)
 			server->caps |= NFS_CAP_ACLS;
 		if (res.has_links != 0)
 			server->caps |= NFS_CAP_HARDLINKS;
@@ -4321,9 +4320,7 @@ static int nfs4_proc_renew(struct nfs_client *clp, struct rpc_cred *cred)
 
 static inline int nfs4_server_supports_acls(struct nfs_server *server)
 {
-	return (server->caps & NFS_CAP_ACLS)
-		&& (server->acl_bitmask & ACL4_SUPPORT_ALLOW_ACL)
-		&& (server->acl_bitmask & ACL4_SUPPORT_DENY_ACL);
+	return server->caps & NFS_CAP_ACLS;
 }
 
 /* Assuming that XATTR_SIZE_MAX is a multiple of PAGE_SIZE, and that

fs/nfs/nfs4xdr.c

@@ -3449,7 +3449,7 @@ static int decode_attr_aclsupport(struct xdr_stream *xdr, uint32_t *bitmap, uint
 {
 	__be32 *p;
 
-	*res = ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL;
+	*res = 0;
 	if (unlikely(bitmap[0] & (FATTR4_WORD0_ACLSUPPORT - 1U)))
 		return -EIO;
 	if (likely(bitmap[0] & FATTR4_WORD0_ACLSUPPORT)) {

fs/nfs/nfstrace.h

@@ -36,6 +36,7 @@
 	__print_flags(v, "|", \
 			{ 1 << NFS_INO_ADVISE_RDPLUS, "ADVISE_RDPLUS" }, \
 			{ 1 << NFS_INO_STALE, "STALE" }, \
+			{ 1 << NFS_INO_INVALIDATING, "INVALIDATING" }, \
 			{ 1 << NFS_INO_FLUSHING, "FLUSHING" }, \
 			{ 1 << NFS_INO_FSCACHE, "FSCACHE" }, \
 			{ 1 << NFS_INO_COMMIT, "COMMIT" }, \

fs/nfs/write.c

@@ -909,9 +909,14 @@ bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx)
  */
 static bool nfs_write_pageuptodate(struct page *page, struct inode *inode)
 {
+	struct nfs_inode *nfsi = NFS_I(inode);
+
 	if (nfs_have_delegated_attributes(inode))
 		goto out;
-	if (NFS_I(inode)->cache_validity & (NFS_INO_INVALID_DATA|NFS_INO_REVAL_PAGECACHE))
+	if (nfsi->cache_validity & (NFS_INO_INVALID_DATA|NFS_INO_REVAL_PAGECACHE))
+		return false;
+	smp_rmb();
+	if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags))
 		return false;
 out:
 	return PageUptodate(page) != 0;

include/linux/nfs_fs.h

@@ -211,6 +211,7 @@ struct nfs_inode {
 #define NFS_INO_ADVISE_RDPLUS	(0)		/* advise readdirplus */
 #define NFS_INO_STALE		(1)		/* possible stale inode */
 #define NFS_INO_ACL_LRU_SET	(2)		/* Inode is on the LRU list */
+#define NFS_INO_INVALIDATING	(3)		/* inode is being invalidated */
 #define NFS_INO_FLUSHING	(4)		/* inode is flushing out data */
 #define NFS_INO_FSCACHE		(5)		/* inode can be cached by FS-Cache */
 #define NFS_INO_FSCACHE_LOCK	(6)		/* FS-Cache cookie management lock */

net/sunrpc/auth_gss/auth_gss.c

@@ -532,13 +532,7 @@ gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 
 static void warn_gssd(void)
 {
-	static unsigned long ratelimit;
-	unsigned long now = jiffies;
-
-	if (time_after(now, ratelimit)) {
-		pr_warn("RPC: AUTH_GSS upcall failed. Please check user daemon is running.\n");
-		ratelimit = now + 15*HZ;
-	}
+	dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
 }
 
 static inline int