Merge tag 'nfs-for-5.7-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - Fix a page leak in nfs_destroy_unlinked_subrequests()

   - Fix use-after-free issues in nfs_pageio_add_request()

   - Fix new mount code constant_table array definitions

   - finish_automount() requires us to hold 2 refs to the mount record

  Features:
   - Improve the accuracy of telldir/seekdir by using 64-bit cookies
     when possible.

   - Allow one RDMA active connection and several zombie connections to
     prevent blocking if the remote server is unresponsive.

   - Limit the size of the NFS access cache by default

   - Reduce the number of references to credentials that are taken by
     NFS

   - pNFS files and flexfiles drivers now support per-layout segment
     COMMIT lists.

   - Enable partial-file layout segments in the pNFS/flexfiles driver.

   - Add support for CB_RECALL_ANY to the pNFS flexfiles layout type

   - pNFS/flexfiles Report NFS4ERR_DELAY and NFS4ERR_GRACE errors from
     the DS using the layouterror mechanism.

  Bugfixes and cleanups:
   - SUNRPC: Fix krb5p regressions

   - Don't specify NFS version in "UDP not supported" error

   - nfsroot: set tcp as the default transport protocol

   - pnfs: Return valid stateids in nfs_layout_find_inode_by_stateid()

   - alloc_nfs_open_context() must use the file cred when available

   - Fix locking when dereferencing the delegation cred

   - Fix memory leaks in O_DIRECT when nfs_get_lock_context() fails

   - Various clean ups of the NFS O_DIRECT commit code

   - Clean up RDMA connect/disconnect

   - Replace zero-length arrays with C99-style flexible arrays"

* tag 'nfs-for-5.7-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (86 commits)
  NFS: Clean up process of marking inode stale.
  SUNRPC: Don't start a timer on an already queued rpc task
  NFS/pnfs: Reference the layout cred in pnfs_prepare_layoutreturn()
  NFS/pnfs: Fix dereference of layout cred in pnfs_layoutcommit_inode()
  NFS: Beware when dereferencing the delegation cred
  NFS: Add a module parameter to set nfs_mountpoint_expiry_timeout
  NFS: finish_automount() requires us to hold 2 refs to the mount record
  NFS: Fix a few constant_table array definitions
  NFS: Try to join page groups before an O_DIRECT retransmission
  NFS: Refactor nfs_lock_and_join_requests()
  NFS: Reverse the submission order of requests in __nfs_pageio_add_request()
  NFS: Clean up nfs_lock_and_join_requests()
  NFS: Remove the redundant function nfs_pgio_has_mirroring()
  NFS: Fix memory leaks in nfs_pageio_stop_mirroring()
  NFS: Fix a request reference leak in nfs_direct_write_clear_reqs()
  NFS: Fix use-after-free issues in nfs_pageio_add_request()
  NFS: Fix races nfs_page_group_destroy() vs nfs_destroy_unlinked_subrequests()
  NFS: Fix a page leak in nfs_destroy_unlinked_subrequests()
  NFS: Remove unused FLUSH_SYNC support in nfs_initiate_pgio()
  pNFS/flexfiles: Specify the layout segment range in LAYOUTGET
  ...

1 files changed, 165 insertions, 154 deletions

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 1865322de142..816e1427f17e 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -378,6 +378,18 @@ nfs_inode_detach_delegation(struct inode *inode)
 }
 
 static void
+nfs_update_delegation_cred(struct nfs_delegation *delegation,
+		const struct cred *cred)
+{
+	const struct cred *old;
+
+	if (cred_fscmp(delegation->cred, cred) != 0) {
+		old = xchg(&delegation->cred, get_cred(cred));
+		put_cred(old);
+	}
+}
+
+static void
 nfs_update_inplace_delegation(struct nfs_delegation *delegation,
 		const struct nfs_delegation *update)
 {
@@ -385,8 +397,14 @@ nfs_update_inplace_delegation(struct nfs_delegation *delegation,
 		delegation->stateid.seqid = update->stateid.seqid;
 		smp_wmb();
 		delegation->type = update->type;
-		if (test_and_clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
+		delegation->pagemod_limit = update->pagemod_limit;
+		if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
+			delegation->change_attr = update->change_attr;
+			nfs_update_delegation_cred(delegation, update->cred);
+			/* smp_mb__before_atomic() is implicit due to xchg() */
+			clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
 			atomic_long_inc(&nfs_active_delegations);
+		}
 	}
 }
 
@@ -545,21 +563,11 @@ static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
 	return ret;
 }
 
-/**
- * nfs_client_return_marked_delegations - return previously marked delegations
- * @clp: nfs_client to process
- *
- * Note that this function is designed to be called by the state
- * manager thread. For this reason, it cannot flush the dirty data,
- * since that could deadlock in case of a state recovery error.
- *
- * Returns zero on success, or a negative errno value.
- */
-int nfs_client_return_marked_delegations(struct nfs_client *clp)
+static int nfs_server_return_marked_delegations(struct nfs_server *server,
+		void __always_unused *data)
 {
 	struct nfs_delegation *delegation;
 	struct nfs_delegation *prev;
-	struct nfs_server *server;
 	struct inode *inode;
 	struct inode *place_holder = NULL;
 	struct nfs_delegation *place_holder_deleg = NULL;
@@ -569,78 +577,79 @@ restart:
 	/*
 	 * To avoid quadratic looping we hold a reference
 	 * to an inode place_holder.  Each time we restart, we
-	 * list nfs_servers from the server of that inode, and
-	 * delegation in the server from the delegations of that
-	 * inode.
+	 * list delegation in the server from the delegations
+	 * of that inode.
 	 * prev is an RCU-protected pointer to a delegation which
 	 * wasn't marked for return and might be a good choice for
 	 * the next place_holder.
 	 */
-	rcu_read_lock();
 	prev = NULL;
+	delegation = NULL;
+	rcu_read_lock();
 	if (place_holder)
-		server = NFS_SERVER(place_holder);
-	else
-		server = list_entry_rcu(clp->cl_superblocks.next,
-					struct nfs_server, client_link);
-	list_for_each_entry_from_rcu(server, &clp->cl_superblocks, client_link) {
-		delegation = NULL;
-		if (place_holder && server == NFS_SERVER(place_holder))
-			delegation = rcu_dereference(NFS_I(place_holder)->delegation);
-		if (!delegation || delegation != place_holder_deleg)
-			delegation = list_entry_rcu(server->delegations.next,
-						    struct nfs_delegation, super_list);
-		list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) {
-			struct inode *to_put = NULL;
-
-			if (!nfs_delegation_need_return(delegation)) {
+		delegation = rcu_dereference(NFS_I(place_holder)->delegation);
+	if (!delegation || delegation != place_holder_deleg)
+		delegation = list_entry_rcu(server->delegations.next,
+					    struct nfs_delegation, super_list);
+	list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) {
+		struct inode *to_put = NULL;
+
+		if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags))
+			continue;
+		if (!nfs_delegation_need_return(delegation)) {
+			if (nfs4_is_valid_delegation(delegation, 0))
 				prev = delegation;
-				continue;
-			}
-			if (!nfs_sb_active(server->super))
-				break; /* continue in outer loop */
-
-			if (prev) {
-				struct inode *tmp;
-
-				tmp = nfs_delegation_grab_inode(prev);
-				if (tmp) {
-					to_put = place_holder;
-					place_holder = tmp;
-					place_holder_deleg = prev;
-				}
-			}
+			continue;
+		}
 
-			inode = nfs_delegation_grab_inode(delegation);
-			if (inode == NULL) {
-				rcu_read_unlock();
-				if (to_put)
-					iput(to_put);
-				nfs_sb_deactive(server->super);
-				goto restart;
+		if (prev) {
+			struct inode *tmp = nfs_delegation_grab_inode(prev);
+			if (tmp) {
+				to_put = place_holder;
+				place_holder = tmp;
+				place_holder_deleg = prev;
 			}
-			delegation = nfs_start_delegation_return_locked(NFS_I(inode));
+		}
+
+		inode = nfs_delegation_grab_inode(delegation);
+		if (inode == NULL) {
 			rcu_read_unlock();
+			iput(to_put);
+			goto restart;
+		}
+		delegation = nfs_start_delegation_return_locked(NFS_I(inode));
+		rcu_read_unlock();
 
-			if (to_put)
-				iput(to_put);
+		iput(to_put);
 
-			err = nfs_end_delegation_return(inode, delegation, 0);
-			iput(inode);
-			nfs_sb_deactive(server->super);
-			cond_resched();
-			if (!err)
-				goto restart;
-			set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
-			if (place_holder)
-				iput(place_holder);
-			return err;
-		}
+		err = nfs_end_delegation_return(inode, delegation, 0);
+		iput(inode);
+		cond_resched();
+		if (!err)
+			goto restart;
+		set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
+		goto out;
 	}
 	rcu_read_unlock();
-	if (place_holder)
-		iput(place_holder);
-	return 0;
+out:
+	iput(place_holder);
+	return err;
+}
+
+/**
+ * nfs_client_return_marked_delegations - return previously marked delegations
+ * @clp: nfs_client to process
+ *
+ * Note that this function is designed to be called by the state
+ * manager thread. For this reason, it cannot flush the dirty data,
+ * since that could deadlock in case of a state recovery error.
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+int nfs_client_return_marked_delegations(struct nfs_client *clp)
+{
+	return nfs_client_for_each_server(clp,
+			nfs_server_return_marked_delegations, NULL);
 }
 
 /**
@@ -1083,53 +1092,51 @@ void nfs_delegation_mark_reclaim(struct nfs_client *clp)
 	rcu_read_unlock();
 }
 
-/**
- * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
- * @clp: nfs_client to process
- *
- */
-void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
+static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
+		void __always_unused *data)
 {
 	struct nfs_delegation *delegation;
-	struct nfs_server *server;
 	struct inode *inode;
-
 restart:
 	rcu_read_lock();
-	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
-		list_for_each_entry_rcu(delegation, &server->delegations,
-								super_list) {
-			if (test_bit(NFS_DELEGATION_INODE_FREEING,
-						&delegation->flags) ||
-			    test_bit(NFS_DELEGATION_RETURNING,
-						&delegation->flags) ||
-			    test_bit(NFS_DELEGATION_NEED_RECLAIM,
-						&delegation->flags) == 0)
-				continue;
-			if (!nfs_sb_active(server->super))
-				break; /* continue in outer loop */
-			inode = nfs_delegation_grab_inode(delegation);
-			if (inode == NULL) {
-				rcu_read_unlock();
-				nfs_sb_deactive(server->super);
-				goto restart;
-			}
-			delegation = nfs_start_delegation_return_locked(NFS_I(inode));
-			rcu_read_unlock();
-			if (delegation != NULL) {
-				if (nfs_detach_delegation(NFS_I(inode), delegation,
-							server) != NULL)
-					nfs_free_delegation(delegation);
-				/* Match nfs_start_delegation_return_locked */
-				nfs_put_delegation(delegation);
-			}
-			iput(inode);
-			nfs_sb_deactive(server->super);
-			cond_resched();
-			goto restart;
+restart_locked:
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+		if (test_bit(NFS_DELEGATION_INODE_FREEING,
+					&delegation->flags) ||
+		    test_bit(NFS_DELEGATION_RETURNING,
+					&delegation->flags) ||
+		    test_bit(NFS_DELEGATION_NEED_RECLAIM,
+					&delegation->flags) == 0)
+			continue;
+		inode = nfs_delegation_grab_inode(delegation);
+		if (inode == NULL)
+			goto restart_locked;
+		delegation = nfs_start_delegation_return_locked(NFS_I(inode));
+		rcu_read_unlock();
+		if (delegation != NULL) {
+			if (nfs_detach_delegation(NFS_I(inode), delegation,
+						server) != NULL)
+				nfs_free_delegation(delegation);
+			/* Match nfs_start_delegation_return_locked */
+			nfs_put_delegation(delegation);
 		}
+		iput(inode);
+		cond_resched();
+		goto restart;
 	}
 	rcu_read_unlock();
+	return 0;
+}
+
+/**
+ * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
+ * @clp: nfs_client to process
+ *
+ */
+void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
+{
+	nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations,
+			NULL);
 }
 
 static inline bool nfs4_server_rebooted(const struct nfs_client *clp)
@@ -1215,62 +1222,61 @@ nfs_delegation_test_free_expired(struct inode *inode,
 		nfs_remove_bad_delegation(inode, stateid);
 }
 
-/**
- * nfs_reap_expired_delegations - reap expired delegations
- * @clp: nfs_client to process
- *
- * Iterates through all the delegations associated with this server and
- * checks if they have may have been revoked. This function is usually
- * expected to be called in cases where the server may have lost its
- * lease.
- */
-void nfs_reap_expired_delegations(struct nfs_client *clp)
+static int nfs_server_reap_expired_delegations(struct nfs_server *server,
+		void __always_unused *data)
 {
 	struct nfs_delegation *delegation;
-	struct nfs_server *server;
 	struct inode *inode;
 	const struct cred *cred;
 	nfs4_stateid stateid;
-
 restart:
 	rcu_read_lock();
-	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
-		list_for_each_entry_rcu(delegation, &server->delegations,
-								super_list) {
-			if (test_bit(NFS_DELEGATION_INODE_FREEING,
-						&delegation->flags) ||
-			    test_bit(NFS_DELEGATION_RETURNING,
-						&delegation->flags) ||
-			    test_bit(NFS_DELEGATION_TEST_EXPIRED,
-						&delegation->flags) == 0)
-				continue;
-			if (!nfs_sb_active(server->super))
-				break; /* continue in outer loop */
-			inode = nfs_delegation_grab_inode(delegation);
-			if (inode == NULL) {
-				rcu_read_unlock();
-				nfs_sb_deactive(server->super);
-				goto restart;
-			}
-			cred = get_cred_rcu(delegation->cred);
-			nfs4_stateid_copy(&stateid, &delegation->stateid);
-			clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
-			rcu_read_unlock();
-			nfs_delegation_test_free_expired(inode, &stateid, cred);
-			put_cred(cred);
-			if (nfs4_server_rebooted(clp)) {
-				nfs_inode_mark_test_expired_delegation(server,inode);
-				iput(inode);
-				nfs_sb_deactive(server->super);
-				return;
-			}
+restart_locked:
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+		if (test_bit(NFS_DELEGATION_INODE_FREEING,
+					&delegation->flags) ||
+		    test_bit(NFS_DELEGATION_RETURNING,
+					&delegation->flags) ||
+		    test_bit(NFS_DELEGATION_TEST_EXPIRED,
+					&delegation->flags) == 0)
+			continue;
+		inode = nfs_delegation_grab_inode(delegation);
+		if (inode == NULL)
+			goto restart_locked;
+		spin_lock(&delegation->lock);
+		cred = get_cred_rcu(delegation->cred);
+		nfs4_stateid_copy(&stateid, &delegation->stateid);
+		spin_unlock(&delegation->lock);
+		clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
+		rcu_read_unlock();
+		nfs_delegation_test_free_expired(inode, &stateid, cred);
+		put_cred(cred);
+		if (!nfs4_server_rebooted(server->nfs_client)) {
 			iput(inode);
-			nfs_sb_deactive(server->super);
 			cond_resched();
 			goto restart;
 		}
+		nfs_inode_mark_test_expired_delegation(server,inode);
+		iput(inode);
+		return -EAGAIN;
 	}
 	rcu_read_unlock();
+	return 0;
+}
+
+/**
+ * nfs_reap_expired_delegations - reap expired delegations
+ * @clp: nfs_client to process
+ *
+ * Iterates through all the delegations associated with this server and
+ * checks if they have may have been revoked. This function is usually
+ * expected to be called in cases where the server may have lost its
+ * lease.
+ */
+void nfs_reap_expired_delegations(struct nfs_client *clp)
+{
+	nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations,
+			NULL);
 }
 
 void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
@@ -1359,11 +1365,14 @@ bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 	struct nfs_delegation *delegation;
-	bool ret;
+	bool ret = false;
 
 	flags &= FMODE_READ|FMODE_WRITE;
 	rcu_read_lock();
 	delegation = rcu_dereference(nfsi->delegation);
+	if (!delegation)
+		goto out;
+	spin_lock(&delegation->lock);
 	ret = nfs4_is_valid_delegation(delegation, flags);
 	if (ret) {
 		nfs4_stateid_copy(dst, &delegation->stateid);
@@ -1371,6 +1380,8 @@ bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
 		if (cred)
 			*cred = get_cred(delegation->cred);
 	}
+	spin_unlock(&delegation->lock);
+out:
 	rcu_read_unlock();
 	return ret;
 }