Merge tag 'afs-fixes-20190516' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull misc AFS fixes from David Howells:
 "This fixes a set of miscellaneous issues in the afs filesystem,
  including:

   - leak of keys on file close.

   - broken error handling in xattr functions.

   - missing locking when updating VL server list.

   - volume location server DNS lookup whereby preloaded cells may not
     ever get a lookup and regular DNS lookups to maintain server lists
     consume power unnecessarily.

   - incorrect error propagation and handling in the fileserver
     iteration code causes operations to sometimes apparently succeed.

   - interruption of server record check/update side op during
     fileserver iteration causes uninterruptible main operations to fail
     unexpectedly.

   - callback promise expiry time miscalculation.

   - over invalidation of the callback promise on directories.

   - double locking on callback break waking up file locking waiters.

   - double increment of the vnode callback break counter.

  Note that it makes some changes outside of the afs code, including:

   - an extra parameter to dns_query() to allow the dns_resolver key
     just accessed to be immediately invalidated. AFS is caching the
     results itself, so the key can be discarded.

   - an interruptible version of wait_var_event().

   - an rxrpc function to allow the maximum lifespan to be set on a
     call.

   - a way for an rxrpc call to be marked as non-interruptible"

* tag 'afs-fixes-20190516' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Fix double inc of vnode->cb_break
  afs: Fix lock-wait/callback-break double locking
  afs: Don't invalidate callback if AFS_VNODE_DIR_VALID not set
  afs: Fix calculation of callback expiry time
  afs: Make dynamic root population wait uninterruptibly for proc_cells_lock
  afs: Make some RPC operations non-interruptible
  rxrpc: Allow the kernel to mark a call as being non-interruptible
  afs: Fix error propagation from server record check/update
  afs: Fix the maximum lifespan of VL and probe calls
  rxrpc: Provide kernel interface to set max lifespan on a call
  afs: Fix "kAFS: AFS vnode with undefined type 0"
  afs: Fix cell DNS lookup
  Add wait_var_event_interruptible()
  dns_resolver: Allow used keys to be invalidated
  afs: Fix afs_cell records to always have a VL server list record
  afs: Fix missing lock when replacing VL server list
  afs: Fix afs_xattr_get_yfs() to not try freeing an error value
  afs: Fix incorrect error handling in afs_xattr_get_acl()
  afs: Fix key leak in afs_release() and afs_evict_inode()

26 files changed, 393 insertions, 289 deletions

diff --git a/fs/afs/addr_list.c b/fs/afs/addr_list.c
index 967db336d11a..9eaff55df7b4 100644
--- a/fs/afs/addr_list.c
+++ b/fs/afs/addr_list.c
@@ -251,7 +251,7 @@ struct afs_vlserver_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry
 	_enter("%s", cell->name);
 
 	ret = dns_query("afsdb", cell->name, cell->name_len, "srv=1",
-			&result, _expiry);
+			&result, _expiry, true);
 	if (ret < 0) {
 		_leave(" = %d [dns]", ret);
 		return ERR_PTR(ret);
diff --git a/fs/afs/afs.h b/fs/afs/afs.h
index d12ffb457e47..74913c707bba 100644
--- a/fs/afs/afs.h
+++ b/fs/afs/afs.h
@@ -23,6 +23,9 @@
 #define AFSPATHMAX		1024	/* Maximum length of a pathname plus NUL */
 #define AFSOPAQUEMAX		1024	/* Maximum length of an opaque field */
 
+#define AFS_VL_MAX_LIFESPAN	(120 * HZ)
+#define AFS_PROBE_MAX_LIFESPAN	(30 * HZ)
+
 typedef u64			afs_volid_t;
 typedef u64			afs_vnodeid_t;
 typedef u64			afs_dataversion_t;
diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index 128f2dbe256a..4876079aa643 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -218,14 +218,8 @@ void __afs_break_callback(struct afs_vnode *vnode)
 		vnode->cb_break++;
 		afs_clear_permits(vnode);
 
-		spin_lock(&vnode->lock);
-
-		_debug("break callback");
-
-		if (list_empty(&vnode->granted_locks) &&
-		    !list_empty(&vnode->pending_locks))
+		if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB)
 			afs_lock_may_be_available(vnode);
-		spin_unlock(&vnode->lock);
 	}
 }
 
diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 9de46116c749..9c3b07ba2222 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -123,6 +123,7 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
 				       const char *name, unsigned int namelen,
 				       const char *addresses)
 {
+	struct afs_vlserver_list *vllist;
 	struct afs_cell *cell;
 	int i, ret;
 
@@ -151,18 +152,14 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
 
 	atomic_set(&cell->usage, 2);
 	INIT_WORK(&cell->manager, afs_manage_cell);
-	cell->flags = ((1 << AFS_CELL_FL_NOT_READY) |
-		       (1 << AFS_CELL_FL_NO_LOOKUP_YET));
 	INIT_LIST_HEAD(&cell->proc_volumes);
 	rwlock_init(&cell->proc_lock);
 	rwlock_init(&cell->vl_servers_lock);
 
-	/* Fill in the VL server list if we were given a list of addresses to
-	 * use.
+	/* Provide a VL server list, filling it in if we were given a list of
+	 * addresses to use.
 	 */
 	if (addresses) {
-		struct afs_vlserver_list *vllist;
-
 		vllist = afs_parse_text_addrs(net,
 					      addresses, strlen(addresses), ':',
 					      VL_SERVICE, AFS_VL_PORT);
@@ -171,19 +168,32 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
 			goto parse_failed;
 		}
 
-		rcu_assign_pointer(cell->vl_servers, vllist);
+		vllist->source = DNS_RECORD_FROM_CONFIG;
+		vllist->status = DNS_LOOKUP_NOT_DONE;
 		cell->dns_expiry = TIME64_MAX;
-		__clear_bit(AFS_CELL_FL_NO_LOOKUP_YET, &cell->flags);
 	} else {
+		ret = -ENOMEM;
+		vllist = afs_alloc_vlserver_list(0);
+		if (!vllist)
+			goto error;
+		vllist->source = DNS_RECORD_UNAVAILABLE;
+		vllist->status = DNS_LOOKUP_NOT_DONE;
 		cell->dns_expiry = ktime_get_real_seconds();
 	}
 
+	rcu_assign_pointer(cell->vl_servers, vllist);
+
+	cell->dns_source = vllist->source;
+	cell->dns_status = vllist->status;
+	smp_store_release(&cell->dns_lookup_count, 1); /* vs source/status */
+
 	_leave(" = %p", cell);
 	return cell;
 
 parse_failed:
 	if (ret == -EINVAL)
 		printk(KERN_ERR "kAFS: bad VL server IP address\n");
+error:
 	kfree(cell);
 	_leave(" = %d", ret);
 	return ERR_PTR(ret);
@@ -208,6 +218,7 @@ struct afs_cell *afs_lookup_cell(struct afs_net *net,
 {
 	struct afs_cell *cell, *candidate, *cursor;
 	struct rb_node *parent, **pp;
+	enum afs_cell_state state;
 	int ret, n;
 
 	_enter("%s,%s", name, vllist);
@@ -267,18 +278,16 @@ struct afs_cell *afs_lookup_cell(struct afs_net *net,
 
 wait_for_cell:
 	_debug("wait_for_cell");
-	ret = wait_on_bit(&cell->flags, AFS_CELL_FL_NOT_READY, TASK_INTERRUPTIBLE);
-	smp_rmb();
-
-	switch (READ_ONCE(cell->state)) {
-	case AFS_CELL_FAILED:
+	wait_var_event(&cell->state,
+		       ({
+			       state = smp_load_acquire(&cell->state); /* vs error */
+			       state == AFS_CELL_ACTIVE || state == AFS_CELL_FAILED;
+		       }));
+
+	/* Check the state obtained from the wait check. */
+	if (state == AFS_CELL_FAILED) {
 		ret = cell->error;
 		goto error;
-	default:
-		_debug("weird %u %d", cell->state, cell->error);
-		goto error;
-	case AFS_CELL_ACTIVE:
-		break;
 	}
 
 	_leave(" = %p [cell]", cell);
@@ -360,16 +369,46 @@ int afs_cell_init(struct afs_net *net, const char *rootcell)
 /*
  * Update a cell's VL server address list from the DNS.
  */
-static void afs_update_cell(struct afs_cell *cell)
+static int afs_update_cell(struct afs_cell *cell)
 {
-	struct afs_vlserver_list *vllist, *old;
+	struct afs_vlserver_list *vllist, *old = NULL, *p;
 	unsigned int min_ttl = READ_ONCE(afs_cell_min_ttl);
 	unsigned int max_ttl = READ_ONCE(afs_cell_max_ttl);
 	time64_t now, expiry = 0;
+	int ret = 0;
 
 	_enter("%s", cell->name);
 
 	vllist = afs_dns_query(cell, &expiry);
+	if (IS_ERR(vllist)) {
+		ret = PTR_ERR(vllist);
+
+		_debug("%s: fail %d", cell->name, ret);
+		if (ret == -ENOMEM)
+			goto out_wake;
+
+		ret = -ENOMEM;
+		vllist = afs_alloc_vlserver_list(0);
+		if (!vllist)
+			goto out_wake;
+
+		switch (ret) {
+		case -ENODATA:
+		case -EDESTADDRREQ:
+			vllist->status = DNS_LOOKUP_GOT_NOT_FOUND;
+			break;
+		case -EAGAIN:
+		case -ECONNREFUSED:
+			vllist->status = DNS_LOOKUP_GOT_TEMP_FAILURE;
+			break;
+		default:
+			vllist->status = DNS_LOOKUP_GOT_LOCAL_FAILURE;
+			break;
+		}
+	}
+
+	_debug("%s: got list %d %d", cell->name, vllist->source, vllist->status);
+	cell->dns_status = vllist->status;
 
 	now = ktime_get_real_seconds();
 	if (min_ttl > max_ttl)
@@ -379,48 +418,47 @@ static void afs_update_cell(struct afs_cell *cell)
 	else if (expiry > now + max_ttl)
 		expiry = now + max_ttl;
 
-	if (IS_ERR(vllist)) {
-		switch (PTR_ERR(vllist)) {
-		case -ENODATA:
-		case -EDESTADDRREQ:
+	_debug("%s: status %d", cell->name, vllist->status);
+	if (vllist->source == DNS_RECORD_UNAVAILABLE) {
+		switch (vllist->status) {
+		case DNS_LOOKUP_GOT_NOT_FOUND:
 			/* The DNS said that the cell does not exist or there
 			 * weren't any addresses to be had.
 			 */
-			set_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags);
-			clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
 			cell->dns_expiry = expiry;
 			break;
 
-		case -EAGAIN:
-		case -ECONNREFUSED:
+		case DNS_LOOKUP_BAD:
+		case DNS_LOOKUP_GOT_LOCAL_FAILURE:
+		case DNS_LOOKUP_GOT_TEMP_FAILURE:
+		case DNS_LOOKUP_GOT_NS_FAILURE:
 		default:
-			set_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
 			cell->dns_expiry = now + 10;
 			break;
 		}
-
-		cell->error = -EDESTADDRREQ;
 	} else {
-		clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
-		clear_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags);
-
-		/* Exclusion on changing vl_addrs is achieved by a
-		 * non-reentrant work item.
-		 */
-		old = rcu_dereference_protected(cell->vl_servers, true);
-		rcu_assign_pointer(cell->vl_servers, vllist);
 		cell->dns_expiry = expiry;
-
-		if (old)
-			afs_put_vlserverlist(cell->net, old);
 	}
 
-	if (test_and_clear_bit(AFS_CELL_FL_NO_LOOKUP_YET, &cell->flags))
-		wake_up_bit(&cell->flags, AFS_CELL_FL_NO_LOOKUP_YET);
+	/* Replace the VL server list if the new record has servers or the old
+	 * record doesn't.
+	 */
+	write_lock(&cell->vl_servers_lock);
+	p = rcu_dereference_protected(cell->vl_servers, true);
+	if (vllist->nr_servers > 0 || p->nr_servers == 0) {
+		rcu_assign_pointer(cell->vl_servers, vllist);
+		cell->dns_source = vllist->source;
+		old = p;
+	}
+	write_unlock(&cell->vl_servers_lock);
+	afs_put_vlserverlist(cell->net, old);
 
-	now = ktime_get_real_seconds();
-	afs_set_cell_timer(cell->net, cell->dns_expiry - now);
-	_leave("");
+out_wake:
+	smp_store_release(&cell->dns_lookup_count,
+			  cell->dns_lookup_count + 1); /* vs source/status */
+	wake_up_var(&cell->dns_lookup_count);
+	_leave(" = %d", ret);
+	return ret;
 }
 
 /*
@@ -491,8 +529,7 @@ void afs_put_cell(struct afs_net *net, struct afs_cell *cell)
 	now = ktime_get_real_seconds();
 	cell->last_inactive = now;
 	expire_delay = 0;
-	if (!test_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags) &&
-	    !test_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags))
+	if (cell->vl_servers->nr_servers)
 		expire_delay = afs_cell_gc_delay;
 
 	if (atomic_dec_return(&cell->usage) > 1)
@@ -623,11 +660,13 @@ again:
 			goto final_destruction;
 		if (cell->state == AFS_CELL_FAILED)
 			goto done;
-		cell->state = AFS_CELL_UNSET;
+		smp_store_release(&cell->state, AFS_CELL_UNSET);
+		wake_up_var(&cell->state);
 		goto again;
 
 	case AFS_CELL_UNSET:
-		cell->state = AFS_CELL_ACTIVATING;
+		smp_store_release(&cell->state, AFS_CELL_ACTIVATING);
+		wake_up_var(&cell->state);
 		goto again;
 
 	case AFS_CELL_ACTIVATING:
@@ -635,28 +674,29 @@ again:
 		if (ret < 0)
 			goto activation_failed;
 
-		cell->state = AFS_CELL_ACTIVE;
-		smp_wmb();
-		clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
-		wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
+		smp_store_release(&cell->state, AFS_CELL_ACTIVE);
+		wake_up_var(&cell->state);
 		goto again;
 
 	case AFS_CELL_ACTIVE:
 		if (atomic_read(&cell->usage) > 1) {
-			time64_t now = ktime_get_real_seconds();
-			if (cell->dns_expiry <= now && net->live)
-				afs_update_cell(cell);
+			if (test_and_clear_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) {
+				ret = afs_update_cell(cell);
+				if (ret < 0)
+					cell->error = ret;
+			}
 			goto done;
 		}
-		cell->state = AFS_CELL_DEACTIVATING;
+		smp_store_release(&cell->state, AFS_CELL_DEACTIVATING);
+		wake_up_var(&cell->state);
 		goto again;
 
 	case AFS_CELL_DEACTIVATING:
-		set_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
 		if (atomic_read(&cell->usage) > 1)
 			goto reverse_deactivation;
 		afs_deactivate_cell(net, cell);
-		cell->state = AFS_CELL_INACTIVE;
+		smp_store_release(&cell->state, AFS_CELL_INACTIVE);
+		wake_up_var(&cell->state);
 		goto again;
 
 	default:
@@ -669,17 +709,13 @@ activation_failed:
 	cell->error = ret;
 	afs_deactivate_cell(net, cell);
 
-	cell->state = AFS_CELL_FAILED;
-	smp_wmb();
-	if (test_and_clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags))
-		wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
+	smp_store_release(&cell->state, AFS_CELL_FAILED); /* vs error */
+	wake_up_var(&cell->state);
 	goto again;
 
 reverse_deactivation:
-	cell->state = AFS_CELL_ACTIVE;
-	smp_wmb();
-	clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
-	wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
+	smp_store_release(&cell->state, AFS_CELL_ACTIVE);
+	wake_up_var(&cell->state);
 	_leave(" [deact->act]");
 	return;
 
@@ -739,11 +775,16 @@ void afs_manage_cells(struct work_struct *work)
 		}
 
 		if (usage == 1) {
+			struct afs_vlserver_list *vllist;
 			time64_t expire_at = cell->last_inactive;
 
-			if (!test_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags) &&
-			    !test_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags))
+			read_lock(&cell->vl_servers_lock);
+			vllist = rcu_dereference_protected(
+				cell->vl_servers,
+				lockdep_is_held(&cell->vl_servers_lock));
+			if (vllist->nr_servers > 0)
 				expire_at += afs_cell_gc_delay;
+			read_unlock(&cell->vl_servers_lock);
 			if (purging || expire_at <= now)
 				sched_cell = true;
 			else if (expire_at < next_manage)
@@ -751,10 +792,8 @@ void afs_manage_cells(struct work_struct *work)
 		}
 
 		if (!purging) {
-			if (cell->dns_expiry <= now)
+			if (test_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags))
 				sched_cell = true;
-			else if (cell->dns_expiry <= next_manage)
-				next_manage = cell->dns_expiry;
 		}
 
 		if (sched_cell)
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 9a466be583d2..c15550310f62 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -704,7 +704,7 @@ static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry,
 		goto no_inline_bulk_status;
 
 	inode = ERR_PTR(-ERESTARTSYS);
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			if (test_bit(AFS_SERVER_FL_NO_IBULK,
 				      &fc.cbi->server->flags)) {
@@ -739,7 +739,7 @@ no_inline_bulk_status:
 	 */
 	cookie->nr_fids = 1;
 	inode = ERR_PTR(-ERESTARTSYS);
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			afs_fs_fetch_status(&fc,
 					    afs_v2net(dvnode),
@@ -1166,7 +1166,7 @@ static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 			afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
@@ -1250,7 +1250,7 @@ static int afs_rmdir(struct inode *dir, struct dentry *dentry)
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 			afs_fs_remove(&fc, vnode, dentry->d_name.name, true,
@@ -1374,7 +1374,7 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
 	spin_unlock(&dentry->d_lock);
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 
@@ -1445,7 +1445,7 @@ static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 			afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
@@ -1510,7 +1510,7 @@ static int afs_link(struct dentry *from, struct inode *dir,
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		if (mutex_lock_interruptible_nested(&vnode->io_lock, 1) < 0) {
 			afs_end_vnode_operation(&fc);
 			goto error_key;
@@ -1584,7 +1584,7 @@ static int afs_symlink(struct inode *dir, struct dentry *dentry,
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 			afs_fs_symlink(&fc, dentry->d_name.name,
@@ -1696,7 +1696,7 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, orig_dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, orig_dvnode, key, true)) {
 		if (orig_dvnode != new_dvnode) {
 			if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) {
 				afs_end_vnode_operation(&fc);
diff --git a/fs/afs/dir_silly.c b/fs/afs/dir_silly.c
index f6f89fdab6b2..fbc2d301ffe8 100644
--- a/fs/afs/dir_silly.c
+++ b/fs/afs/dir_silly.c
@@ -30,7 +30,7 @@ static int afs_do_silly_rename(struct afs_vnode *dvnode, struct afs_vnode *vnode
 	_enter("%pd,%pd", old, new);
 
 	trace_afs_silly_rename(vnode, false);
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 			afs_fs_rename(&fc, old->d_name.name,
@@ -149,7 +149,7 @@ static int afs_do_silly_unlink(struct afs_vnode *dvnode, struct afs_vnode *vnode
 	_enter("");
 
 	trace_afs_silly_rename(vnode, true);
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, false)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 
diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c
index a9ba81ddf154..af1689d1f32e 100644
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -46,7 +46,7 @@ static int afs_probe_cell_name(struct dentry *dentry)
 		return 0;
 	}
 
-	ret = dns_query("afsdb", name, len, "srv=1", NULL, NULL);
+	ret = dns_query("afsdb", name, len, "srv=1", NULL, NULL, false);
 	if (ret == -ENODATA)
 		ret = -EDESTADDRREQ;
 	return ret;
@@ -261,8 +261,7 @@ int afs_dynroot_populate(struct super_block *sb)
 	struct afs_net *net = afs_sb2net(sb);
 	int ret;
 
-	if (mutex_lock_interruptible(&net->proc_cells_lock) < 0)
-		return -ERESTARTSYS;
+	mutex_lock(&net->proc_cells_lock);
 
 	net->dynroot_sb = sb;
 	hlist_for_each_entry(cell, &net->proc_cells, proc_link) {
diff --git a/fs/afs/file.c b/fs/afs/file.c
index e8d6619890a9..f59c6149fa02 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -170,11 +170,12 @@ int afs_release(struct inode *inode, struct file *file)
 {
 	struct afs_vnode *vnode = AFS_FS_I(inode);
 	struct afs_file *af = file->private_data;
+	int ret = 0;
 
 	_enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
 
 	if ((file->f_mode & FMODE_WRITE))
-		return vfs_fsync(file, 0);
+		ret = vfs_fsync(file, 0);
 
 	file->private_data = NULL;
 	if (af->wb)
@@ -182,8 +183,8 @@ int afs_release(struct inode *inode, struct file *file)
 	key_put(af->key);
 	kfree(af);
 	afs_prune_wb_keys(vnode);
-	_leave(" = 0");
-	return 0;
+	_leave(" = %d", ret);
+	return ret;
 }
 
 /*
@@ -237,7 +238,7 @@ int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *de
 	       key_serial(key));
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, vnode, key)) {
+	if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(vnode);
 			afs_fs_fetch_data(&fc, desc);
diff --git a/fs/afs/flock.c b/fs/afs/flock.c
index adc88eff7849..c91cd201013f 100644
--- a/fs/afs/flock.c
+++ b/fs/afs/flock.c
@@ -41,9 +41,6 @@ void afs_lock_may_be_available(struct afs_vnode *vnode)
 {
 	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
 
-	if (vnode->lock_state != AFS_VNODE_LOCK_WAITING_FOR_CB)
-		return;
-
 	spin_lock(&vnode->lock);
 	if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB)
 		afs_next_locker(vnode, 0);
@@ -196,7 +193,7 @@ static int afs_set_lock(struct afs_vnode *vnode, struct key *key,
 	       key_serial(key), type);
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, vnode, key)) {
+	if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(vnode);
 			afs_fs_set_lock(&fc, type);
@@ -227,7 +224,7 @@ static int afs_extend_lock(struct afs_vnode *vnode, struct key *key)
 	       key_serial(key));
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, vnode, key)) {
+	if (afs_begin_vnode_operation(&fc, vnode, key, false)) {
 		while (afs_select_current_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(vnode);
 			afs_fs_extend_lock(&fc);
@@ -258,7 +255,7 @@ static int afs_release_lock(struct afs_vnode *vnode, struct key *key)
 	       key_serial(key));
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, vnode, key)) {
+	if (afs_begin_vnode_operation(&fc, vnode, key, false)) {
 		while (afs_select_current_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(vnode);
 			afs_fs_release_lock(&fc);
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 1296f5dc4c1e..388750d80cab 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -256,6 +256,23 @@ static int afs_decode_status(struct afs_call *call,
 	return ret;
 }
 
+static time64_t xdr_decode_expiry(struct afs_call *call, u32 expiry)
+{
+	return ktime_divns(call->reply_time, NSEC_PER_SEC) + expiry;
+}
+
+static void xdr_decode_AFSCallBack_raw(struct afs_call *call,
+				       struct afs_callback *cb,
+				       const __be32 **_bp)
+{
+	const __be32 *bp = *_bp;
+
+	cb->version	= ntohl(*bp++);
+	cb->expires_at	= xdr_decode_expiry(call, ntohl(*bp++));
+	cb->type	= ntohl(*bp++);
+	*_bp = bp;
+}
+
 /*
  * decode an AFSCallBack block
  */
@@ -264,46 +281,26 @@ static void xdr_decode_AFSCallBack(struct afs_call *call,
 				   const __be32 **_bp)
 {
 	struct afs_cb_interest *old, *cbi = call->cbi;
-	const __be32 *bp = *_bp;
-	u32 cb_expiry;
+	struct afs_callback cb;
+
+	xdr_decode_AFSCallBack_raw(call, &cb, _bp);
 
 	write_seqlock(&vnode->cb_lock);
 
 	if (!afs_cb_is_broken(call->cb_break, vnode, cbi)) {
-		vnode->cb_version	= ntohl(*bp++);
-		cb_expiry		= ntohl(*bp++);
-		vnode->cb_type		= ntohl(*bp++);
-		vnode->cb_expires_at	= cb_expiry + ktime_get_real_seconds();
+		vnode->cb_version	= cb.version;
+		vnode->cb_type		= cb.type;
+		vnode->cb_expires_at	= cb.expires_at;
 		old = vnode->cb_interest;
 		if (old != call->cbi) {
 			vnode->cb_interest = cbi;
 			cbi = old;
 		}
 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
-	} else {
-		bp += 3;
 	}
 
 	write_sequnlock(&vnode->cb_lock);
 	call->cbi = cbi;
-	*_bp = bp;
-}
-
-static ktime_t xdr_decode_expiry(struct afs_call *call, u32 expiry)
-{
-	return ktime_add_ns(call->reply_time, expiry * NSEC_PER_SEC);
-}
-
-static void xdr_decode_AFSCallBack_raw(struct afs_call *call,
-				       const __be32 **_bp,
-				       struct afs_callback *cb)
-{
-	const __be32 *bp = *_bp;
-
-	cb->version	= ntohl(*bp++);
-	cb->expires_at	= xdr_decode_expiry(call, ntohl(*bp++));
-	cb->type	= ntohl(*bp++);
-	*_bp = bp;
 }
 
 /*
@@ -469,6 +466,7 @@ int afs_fs_fetch_file_status(struct afs_fs_cursor *fc, struct afs_volsync *volsy
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call(call, &vnode->fid);
 
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -664,6 +662,7 @@ static int afs_fs_fetch_data64(struct afs_fs_cursor *fc, struct afs_read *req)
 	call->cb_break = fc->cb_break;
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call(call, &vnode->fid);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -712,6 +711,7 @@ int afs_fs_fetch_data(struct afs_fs_cursor *fc, struct afs_read *req)
 	call->cb_break = fc->cb_break;
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call(call, &vnode->fid);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -741,7 +741,7 @@ static int afs_deliver_fs_create_vnode(struct afs_call *call)
 				&call->expected_version, NULL);
 	if (ret < 0)
 		return ret;
-	xdr_decode_AFSCallBack_raw(call, &bp, call->reply[3]);
+	xdr_decode_AFSCallBack_raw(call, call->reply[3], &bp);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
 	_leave(" = 0 [done]");
@@ -833,6 +833,7 @@ int afs_fs_create(struct afs_fs_cursor *fc,
 
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call1(call, &vnode->fid, name);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -930,6 +931,7 @@ int afs_fs_remove(struct afs_fs_cursor *fc, struct afs_vnode *vnode,
 
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call1(call, &dvnode->fid, name);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -1023,6 +1025,7 @@ int afs_fs_link(struct afs_fs_cursor *fc, struct afs_vnode *vnode,
 
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call1(call, &vnode->fid, name);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -1138,6 +1141,7 @@ int afs_fs_symlink(struct afs_fs_cursor *fc,
 
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call1(call, &vnode->fid, name);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -1257,6 +1261,7 @@ int afs_fs_rename(struct afs_fs_cursor *fc,
 
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call2(call, &orig_dvnode->fid, orig_name, new_name);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -1362,6 +1367,7 @@ static int afs_fs_store_data64(struct afs_fs_cursor *fc,
 	*bp++ = htonl((u32) i_size);
 
 	trace_afs_make_fs_call(call, &vnode->fid);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -1439,6 +1445,7 @@ int afs_fs_store_data(struct afs_fs_cursor *fc, struct address_space *mapping,
 
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call(call, &vnode->fid);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -1538,6 +1545,7 @@ static int afs_fs_setattr_size64(struct afs_fs_cursor *fc, struct iattr *attr)
 
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call(call, &vnode->fid);
+	afs_set_fc_call(call, fc);
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
@@ -1585,6 +1593,7 @@ static int afs_fs_setattr_size(struct afs_fs_cursor *fc, struct iattr *attr)
 
 	afs_use_fs_server(call, fc->cbi);<