1 files changed, 632 insertions, 344 deletions

diff --git a/fs/afs/flock.c b/fs/afs/flock.c
index a8cf2cff836c..f0e96a35093f 100644
--- a/fs/afs/flock.c
+++ b/fs/afs/flock.c
@@ -1,68 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* AFS file locking support
  *
  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */
 
 #include "internal.h"
 
 #define AFS_LOCK_GRANTED	0
 #define AFS_LOCK_PENDING	1
+#define AFS_LOCK_YOUR_TRY	2
+
+struct workqueue_struct *afs_lock_manager;
 
+static void afs_next_locker(struct afs_vnode *vnode, int error);
 static void afs_fl_copy_lock(struct file_lock *new, struct file_lock *fl);
 static void afs_fl_release_private(struct file_lock *fl);
 
-static struct workqueue_struct *afs_lock_manager;
-static DEFINE_MUTEX(afs_lock_manager_mutex);
-
 static const struct file_lock_operations afs_lock_ops = {
 	.fl_copy_lock		= afs_fl_copy_lock,
 	.fl_release_private	= afs_fl_release_private,
 };
 
-/*
- * initialise the lock manager thread if it isn't already running
- */
-static int afs_init_lock_manager(void)
+static inline void afs_set_lock_state(struct afs_vnode *vnode, enum afs_lock_state state)
 {
-	int ret;
-
-	ret = 0;
-	if (!afs_lock_manager) {
-		mutex_lock(&afs_lock_manager_mutex);
-		if (!afs_lock_manager) {
-			afs_lock_manager =
-				create_singlethread_workqueue("kafs_lockd");
-			if (!afs_lock_manager)
-				ret = -ENOMEM;
-		}
-		mutex_unlock(&afs_lock_manager_mutex);
-	}
-	return ret;
+	_debug("STATE %u -> %u", vnode->lock_state, state);
+	vnode->lock_state = state;
 }
 
-/*
- * destroy the lock manager thread if it's running
- */
-void __exit afs_kill_lock_manager(void)
-{
-	if (afs_lock_manager)
-		destroy_workqueue(afs_lock_manager);
-}
+static atomic_t afs_file_lock_debug_id;
 
 /*
  * if the callback is broken on this vnode, then the lock may now be available
  */
 void afs_lock_may_be_available(struct afs_vnode *vnode)
 {
-	_enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
+	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
 
-	queue_delayed_work(afs_lock_manager, &vnode->lock_work, 0);
+	spin_lock(&vnode->lock);
+	if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB)
+		afs_next_locker(vnode, 0);
+	trace_afs_flock_ev(vnode, NULL, afs_flock_callback_break, 0);
+	spin_unlock(&vnode->lock);
 }
 
 /*
@@ -71,8 +50,36 @@ void afs_lock_may_be_available(struct afs_vnode *vnode)
  */
 static void afs_schedule_lock_extension(struct afs_vnode *vnode)
 {
-	queue_delayed_work(afs_lock_manager, &vnode->lock_work,
-			   AFS_LOCKWAIT * HZ / 2);
+	ktime_t expires_at, now, duration;
+	u64 duration_j;
+
+	expires_at = ktime_add_ms(vnode->locked_at, AFS_LOCKWAIT * 1000 / 2);
+	now = ktime_get_real();
+	duration = ktime_sub(expires_at, now);
+	if (duration <= 0)
+		duration_j = 0;
+	else
+		duration_j = nsecs_to_jiffies(ktime_to_ns(duration));
+
+	queue_delayed_work(afs_lock_manager, &vnode->lock_work, duration_j);
+}
+
+/*
+ * In the case of successful completion of a lock operation, record the time
+ * the reply appeared and start the lock extension timer.
+ */
+void afs_lock_op_done(struct afs_call *call)
+{
+	struct afs_operation *op = call->op;
+	struct afs_vnode *vnode = op->file[0].vnode;
+
+	if (call->error == 0) {
+		spin_lock(&vnode->lock);
+		trace_afs_flock_ev(vnode, NULL, afs_flock_timestamp, 0);
+		vnode->locked_at = call->issue_time;
+		afs_schedule_lock_extension(vnode);
+		spin_unlock(&vnode->lock);
+	}
 }
 
 /*
@@ -80,22 +87,190 @@ static void afs_schedule_lock_extension(struct afs_vnode *vnode)
  * first lock in the queue is itself a readlock)
  * - the caller must hold the vnode lock
  */
-static void afs_grant_locks(struct afs_vnode *vnode, struct file_lock *fl)
+static void afs_grant_locks(struct afs_vnode *vnode)
 {
 	struct file_lock *p, *_p;
+	bool exclusive = (vnode->lock_type == AFS_LOCK_WRITE);
 
-	list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks);
-	if (fl->fl_type == F_RDLCK) {
-		list_for_each_entry_safe(p, _p, &vnode->pending_locks,
-					 fl_u.afs.link) {
-			if (p->fl_type == F_RDLCK) {
-				p->fl_u.afs.state = AFS_LOCK_GRANTED;
-				list_move_tail(&p->fl_u.afs.link,
-					       &vnode->granted_locks);
-				wake_up(&p->fl_wait);
-			}
+	list_for_each_entry_safe(p, _p, &vnode->pending_locks, fl_u.afs.link) {
+		if (!exclusive && lock_is_write(p))
+			continue;
+
+		list_move_tail(&p->fl_u.afs.link, &vnode->granted_locks);
+		p->fl_u.afs.state = AFS_LOCK_GRANTED;
+		trace_afs_flock_op(vnode, p, afs_flock_op_grant);
+		locks_wake_up(p);
+	}
+}
+
+/*
+ * If an error is specified, reject every pending lock that matches the
+ * authentication and type of the lock we failed to get.  If there are any
+ * remaining lockers, try to wake up one of them to have a go.
+ */
+static void afs_next_locker(struct afs_vnode *vnode, int error)
+{
+	struct file_lock *p, *_p, *next = NULL;
+	struct key *key = vnode->lock_key;
+	unsigned int type = F_RDLCK;
+
+	_enter("");
+
+	if (vnode->lock_type == AFS_LOCK_WRITE)
+		type = F_WRLCK;
+
+	list_for_each_entry_safe(p, _p, &vnode->pending_locks, fl_u.afs.link) {
+		if (error &&
+		    p->c.flc_type == type &&
+		    afs_file_key(p->c.flc_file) == key) {
+			list_del_init(&p->fl_u.afs.link);
+			p->fl_u.afs.state = error;
+			locks_wake_up(p);
 		}
+
+		/* Select the next locker to hand off to. */
+		if (next && (lock_is_write(next) || lock_is_read(p)))
+			continue;
+		next = p;
+	}
+
+	vnode->lock_key = NULL;
+	key_put(key);
+
+	if (next) {
+		afs_set_lock_state(vnode, AFS_VNODE_LOCK_SETTING);
+		next->fl_u.afs.state = AFS_LOCK_YOUR_TRY;
+		trace_afs_flock_op(vnode, next, afs_flock_op_wake);
+		locks_wake_up(next);
+	} else {
+		afs_set_lock_state(vnode, AFS_VNODE_LOCK_NONE);
+		trace_afs_flock_ev(vnode, NULL, afs_flock_no_lockers, 0);
 	}
+
+	_leave("");
+}
+
+/*
+ * Kill off all waiters in the the pending lock queue due to the vnode being
+ * deleted.
+ */
+static void afs_kill_lockers_enoent(struct afs_vnode *vnode)
+{
+	struct file_lock *p;
+
+	afs_set_lock_state(vnode, AFS_VNODE_LOCK_DELETED);
+
+	while (!list_empty(&vnode->pending_locks)) {
+		p = list_entry(vnode->pending_locks.next,
+			       struct file_lock, fl_u.afs.link);
+		list_del_init(&p->fl_u.afs.link);
+		p->fl_u.afs.state = -ENOENT;
+		locks_wake_up(p);
+	}
+
+	key_put(vnode->lock_key);
+	vnode->lock_key = NULL;
+}
+
+static void afs_lock_success(struct afs_operation *op)
+{
+	_enter("op=%08x", op->debug_id);
+	afs_vnode_commit_status(op, &op->file[0]);
+}
+
+static const struct afs_operation_ops afs_set_lock_operation = {
+	.issue_afs_rpc	= afs_fs_set_lock,
+	.issue_yfs_rpc	= yfs_fs_set_lock,
+	.success	= afs_lock_success,
+	.aborted	= afs_check_for_remote_deletion,
+};
+
+/*
+ * Get a lock on a file
+ */
+static int afs_set_lock(struct afs_vnode *vnode, struct key *key,
+			afs_lock_type_t type)
+{
+	struct afs_operation *op;
+
+	_enter("%s{%llx:%llu.%u},%x,%u",
+	       vnode->volume->name,
+	       vnode->fid.vid,
+	       vnode->fid.vnode,
+	       vnode->fid.unique,
+	       key_serial(key), type);
+
+	op = afs_alloc_operation(key, vnode->volume);
+	if (IS_ERR(op))
+		return PTR_ERR(op);
+
+	afs_op_set_vnode(op, 0, vnode);
+
+	op->lock.type	= type;
+	op->ops		= &afs_set_lock_operation;
+	return afs_do_sync_operation(op);
+}
+
+static const struct afs_operation_ops afs_extend_lock_operation = {
+	.issue_afs_rpc	= afs_fs_extend_lock,
+	.issue_yfs_rpc	= yfs_fs_extend_lock,
+	.success	= afs_lock_success,
+};
+
+/*
+ * Extend a lock on a file
+ */
+static int afs_extend_lock(struct afs_vnode *vnode, struct key *key)
+{
+	struct afs_operation *op;
+
+	_enter("%s{%llx:%llu.%u},%x",
+	       vnode->volume->name,
+	       vnode->fid.vid,
+	       vnode->fid.vnode,
+	       vnode->fid.unique,
+	       key_serial(key));
+
+	op = afs_alloc_operation(key, vnode->volume);
+	if (IS_ERR(op))
+		return PTR_ERR(op);
+
+	afs_op_set_vnode(op, 0, vnode);
+
+	op->flags	|= AFS_OPERATION_UNINTR;
+	op->ops		= &afs_extend_lock_operation;
+	return afs_do_sync_operation(op);
+}
+
+static const struct afs_operation_ops afs_release_lock_operation = {
+	.issue_afs_rpc	= afs_fs_release_lock,
+	.issue_yfs_rpc	= yfs_fs_release_lock,
+	.success	= afs_lock_success,
+};
+
+/*
+ * Release a lock on a file
+ */
+static int afs_release_lock(struct afs_vnode *vnode, struct key *key)
+{
+	struct afs_operation *op;
+
+	_enter("%s{%llx:%llu.%u},%x",
+	       vnode->volume->name,
+	       vnode->fid.vid,
+	       vnode->fid.vnode,
+	       vnode->fid.unique,
+	       key_serial(key));
+
+	op = afs_alloc_operation(key, vnode->volume);
+	if (IS_ERR(op))
+		return PTR_ERR(op);
+
+	afs_op_set_vnode(op, 0, vnode);
+
+	op->flags	|= AFS_OPERATION_UNINTR;
+	op->ops		= &afs_release_lock_operation;
+	return afs_do_sync_operation(op);
 }
 
 /*
@@ -107,126 +282,105 @@ void afs_lock_work(struct work_struct *work)
 {
 	struct afs_vnode *vnode =
 		container_of(work, struct afs_vnode, lock_work.work);
-	struct file_lock *fl;
-	afs_lock_type_t type;
 	struct key *key;
 	int ret;
 
-	_enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
+	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
 
 	spin_lock(&vnode->lock);
 
-	if (test_bit(AFS_VNODE_UNLOCKING, &vnode->flags)) {
-		_debug("unlock");
+again:
+	_debug("wstate %u for %p", vnode->lock_state, vnode);
+	switch (vnode->lock_state) {
+	case AFS_VNODE_LOCK_NEED_UNLOCK:
+		afs_set_lock_state(vnode, AFS_VNODE_LOCK_UNLOCKING);
+		trace_afs_flock_ev(vnode, NULL, afs_flock_work_unlocking, 0);
 		spin_unlock(&vnode->lock);
 
 		/* attempt to release the server lock; if it fails, we just
-		 * wait 5 minutes and it'll time out anyway */
-		ret = afs_vnode_release_lock(vnode, vnode->unlock_key);
-		if (ret < 0)
+		 * wait 5 minutes and it'll expire anyway */
+		ret = afs_release_lock(vnode, vnode->lock_key);
+		if (ret < 0 && vnode->lock_state != AFS_VNODE_LOCK_DELETED) {
+			trace_afs_flock_ev(vnode, NULL, afs_flock_release_fail,
+					   ret);
 			printk(KERN_WARNING "AFS:"
-			       " Failed to release lock on {%x:%x} error %d\n",
+			       " Failed to release lock on {%llx:%llx} error %d\n",
 			       vnode->fid.vid, vnode->fid.vnode, ret);
+		}
 
 		spin_lock(&vnode->lock);
-		key_put(vnode->unlock_key);
-		vnode->unlock_key = NULL;
-		clear_bit(AFS_VNODE_UNLOCKING, &vnode->flags);
-	}
+		if (ret == -ENOENT)
+			afs_kill_lockers_enoent(vnode);
+		else
+			afs_next_locker(vnode, 0);
+		spin_unlock(&vnode->lock);
+		return;
 
-	/* if we've got a lock, then it must be time to extend that lock as AFS
-	 * locks time out after 5 minutes */
-	if (!list_empty(&vnode->granted_locks)) {
+	/* If we've already got a lock, then it must be time to extend that
+	 * lock as AFS locks time out after 5 minutes.
+	 */
+	case AFS_VNODE_LOCK_GRANTED:
 		_debug("extend");
 
-		if (test_and_set_bit(AFS_VNODE_LOCKING, &vnode->flags))
-			BUG();
-		fl = list_entry(vnode->granted_locks.next,
-				struct file_lock, fl_u.afs.link);
-		key = key_get(fl->fl_file->private_data);
+		ASSERT(!list_empty(&vnode->granted_locks));
+
+		key = key_get(vnode->lock_key);
+		afs_set_lock_state(vnode, AFS_VNODE_LOCK_EXTENDING);
+		trace_afs_flock_ev(vnode, NULL, afs_flock_work_extending, 0);
 		spin_unlock(&vnode->lock);
 
-		ret = afs_vnode_extend_lock(vnode, key);
-		clear_bit(AFS_VNODE_LOCKING, &vnode->flags);
+		ret = afs_extend_lock(vnode, key); /* RPC */
 		key_put(key);
-		switch (ret) {
-		case 0:
-			afs_schedule_lock_extension(vnode);
-			break;
-		default:
-			/* ummm... we failed to extend the lock - retry
-			 * extension shortly */
-			printk(KERN_WARNING "AFS:"
-			       " Failed to extend lock on {%x:%x} error %d\n",
-			       vnode->fid.vid, vnode->fid.vnode, ret);
+
+		if (ret < 0) {
+			trace_afs_flock_ev(vnode, NULL, afs_flock_extend_fail,
+					   ret);
+			pr_warn("AFS: Failed to extend lock on {%llx:%llx} error %d\n",
+				vnode->fid.vid, vnode->fid.vnode, ret);
+		}
+
+		spin_lock(&vnode->lock);
+
+		if (ret == -ENOENT) {
+			afs_kill_lockers_enoent(vnode);
+			spin_unlock(&vnode->lock);
+			return;
+		}
+
+		if (vnode->lock_state != AFS_VNODE_LOCK_EXTENDING)
+			goto again;
+		afs_set_lock_state(vnode, AFS_VNODE_LOCK_GRANTED);
+
+		if (ret != 0)
 			queue_delayed_work(afs_lock_manager, &vnode->lock_work,
 					   HZ * 10);
-			break;
-		}
-		_leave(" [extend]");
+		spin_unlock(&vnode->lock);
+		_leave(" [ext]");
 		return;
-	}
 
-	/* if we don't have a granted lock, then we must've been called back by
-	 * the server, and so if might be possible to get a lock we're
-	 * currently waiting for */
-	if (!list_empty(&vnode->pending_locks)) {
-		_debug("get");
-
-		if (test_and_set_bit(AFS_VNODE_LOCKING, &vnode->flags))
-			BUG();
-		fl = list_entry(vnode->pending_locks.next,
-				struct file_lock, fl_u.afs.link);
-		key = key_get(fl->fl_file->private_data);
-		type = (fl->fl_type == F_RDLCK) ?
-			AFS_LOCK_READ : AFS_LOCK_WRITE;
+	/* If we're waiting for a callback to indicate lock release, we can't
+	 * actually rely on this, so need to recheck at regular intervals.  The
+	 * problem is that the server might not notify us if the lock just
+	 * expires (say because a client died) rather than being explicitly
+	 * released.
+	 */
+	case AFS_VNODE_LOCK_WAITING_FOR_CB:
+		_debug("retry");
+		afs_next_locker(vnode, 0);
 		spin_unlock(&vnode->lock);
+		return;
 
-		ret = afs_vnode_set_lock(vnode, key, type);
-		clear_bit(AFS_VNODE_LOCKING, &vnode->flags);
-		switch (ret) {
-		case -EWOULDBLOCK:
-			_debug("blocked");
-			break;
-		case 0:
-			_debug("acquired");
-			if (type == AFS_LOCK_READ)
-				set_bit(AFS_VNODE_READLOCKED, &vnode->flags);
-			else
-				set_bit(AFS_VNODE_WRITELOCKED, &vnode->flags);
-			ret = AFS_LOCK_GRANTED;
-		default:
-			spin_lock(&vnode->lock);
-			/* the pending lock may have been withdrawn due to a
-			 * signal */
-			if (list_entry(vnode->pending_locks.next,
-				       struct file_lock, fl_u.afs.link) == fl) {
-				fl->fl_u.afs.state = ret;
-				if (ret == AFS_LOCK_GRANTED)
-					afs_grant_locks(vnode, fl);
-				else
-					list_del_init(&fl->fl_u.afs.link);
-				wake_up(&fl->fl_wait);
-				spin_unlock(&vnode->lock);
-			} else {
-				_debug("withdrawn");
-				clear_bit(AFS_VNODE_READLOCKED, &vnode->flags);
-				clear_bit(AFS_VNODE_WRITELOCKED, &vnode->flags);
-				spin_unlock(&vnode->lock);
-				afs_vnode_release_lock(vnode, key);
-				if (!list_empty(&vnode->pending_locks))
-					afs_lock_may_be_available(vnode);
-			}
-			break;
-		}
-		key_put(key);
-		_leave(" [pend]");
+	case AFS_VNODE_LOCK_DELETED:
+		afs_kill_lockers_enoent(vnode);
+		spin_unlock(&vnode->lock);
 		return;
-	}
 
-	/* looks like the lock request was withdrawn on a signal */
-	spin_unlock(&vnode->lock);
-	_leave(" [no locks]");
+	default:
+		/* Looks like a lock request was withdrawn. */
+		spin_unlock(&vnode->lock);
+		_leave(" [no]");
+		return;
+	}
 }
 
 /*
@@ -235,16 +389,60 @@ void afs_lock_work(struct work_struct *work)
  * AF_RXRPC
  * - the caller must hold the vnode lock
  */
-static void afs_defer_unlock(struct afs_vnode *vnode, struct key *key)
+static void afs_defer_unlock(struct afs_vnode *vnode)
 {
-	cancel_delayed_work(&vnode->lock_work);
-	if (!test_and_clear_bit(AFS_VNODE_READLOCKED, &vnode->flags) &&
-	    !test_and_clear_bit(AFS_VNODE_WRITELOCKED, &vnode->flags))
-		BUG();
-	if (test_and_set_bit(AFS_VNODE_UNLOCKING, &vnode->flags))
-		BUG();
-	vnode->unlock_key = key_get(key);
-	afs_lock_may_be_available(vnode);
+	_enter("%u", vnode->lock_state);
+
+	if (list_empty(&vnode->granted_locks) &&
+	    (vnode->lock_state == AFS_VNODE_LOCK_GRANTED ||
+	     vnode->lock_state == AFS_VNODE_LOCK_EXTENDING)) {
+		cancel_delayed_work(&vnode->lock_work);
+
+		afs_set_lock_state(vnode, AFS_VNODE_LOCK_NEED_UNLOCK);
+		trace_afs_flock_ev(vnode, NULL, afs_flock_defer_unlock, 0);
+		queue_delayed_work(afs_lock_manager, &vnode->lock_work, 0);
+	}
+}
+
+/*
+ * Check that our view of the file metadata is up to date and check to see
+ * whether we think that we have a locking permit.
+ */
+static int afs_do_setlk_check(struct afs_vnode *vnode, struct key *key,
+			      enum afs_flock_mode mode, afs_lock_type_t type)
+{
+	afs_access_t access;
+	int ret;
+
+	/* Make sure we've got a callback on this file and that our view of the
+	 * data version is up to date.
+	 */
+	ret = afs_validate(vnode, key);
+	if (ret < 0)
+		return ret;
+
+	/* Check the permission set to see if we're actually going to be
+	 * allowed to get a lock on this file.
+	 */
+	ret = afs_check_permit(vnode, key, &access);
+	if (ret < 0)
+		return ret;
+
+	/* At a rough estimation, you need LOCK, WRITE or INSERT perm to
+	 * read-lock a file and WRITE or INSERT perm to write-lock a file.
+	 *
+	 * We can't rely on the server to do this for us since if we want to
+	 * share a read lock that we already have, we won't go the server.
+	 */
+	if (type == AFS_LOCK_READ) {
+		if (!(access & (AFS_ACE_INSERT | AFS_ACE_WRITE | AFS_ACE_LOCK)))
+			return -EACCES;
+	} else {
+		if (!(access & (AFS_ACE_INSERT | AFS_ACE_WRITE)))
+			return -EACCES;
+	}
+
+	return 0;
 }
 
 /*
@@ -254,185 +452,247 @@ static int afs_do_setlk(struct file *file, struct file_lock *fl)
 {
 	struct inode *inode = file_inode(file);
 	struct afs_vnode *vnode = AFS_FS_I(inode);
+	enum afs_flock_mode mode = AFS_FS_S(inode->i_sb)->flock_mode;
 	afs_lock_type_t type;
-	struct key *key = file->private_data;
+	struct key *key = afs_file_key(file);
+	bool partial, no_server_lock = false;
 	int ret;
 
-	_enter("{%x:%u},%u", vnode->fid.vid, vnode->fid.vnode, fl->fl_type);
+	if (mode == afs_flock_mode_unset)
+		mode = afs_flock_mode_openafs;
 
-	/* only whole-file locks are supported */
-	if (fl->fl_start != 0 || fl->fl_end != OFFSET_MAX)
-		return -EINVAL;
-
-	ret = afs_init_lock_manager();
-	if (ret < 0)
-		return ret;
+	_enter("{%llx:%llu},%llu-%llu,%u,%u",
+	       vnode->fid.vid, vnode->fid.vnode,
+	       fl->fl_start, fl->fl_end, fl->c.flc_type, mode);
 
 	fl->fl_ops = &afs_lock_ops;
 	INIT_LIST_HEAD(&fl->fl_u.afs.link);
 	fl->fl_u.afs.state = AFS_LOCK_PENDING;
 
-	type = (fl->fl_type == F_RDLCK) ? AFS_LOCK_READ : AFS_LOCK_WRITE;
-
-	spin_lock(&inode->i_lock);
+	partial = (fl->fl_start != 0 || fl->fl_end != OFFSET_MAX);
+	type = lock_is_read(fl) ? AFS_LOCK_READ : AFS_LOCK_WRITE;
+	if (mode == afs_flock_mode_write && partial)
+		type = AFS_LOCK_WRITE;
 
-	/* make sure we've got a callback on this file and that our view of the
-	 * data version is up to date */
-	ret = afs_vnode_fetch_status(vnode, NULL, key);
+	ret = afs_do_setlk_check(vnode, key, mode, type);
 	if (ret < 0)
-		goto error;
+		return ret;
 
-	if (vnode->status.lock_count != 0 && !(fl->fl_flags & FL_SLEEP)) {
-		ret = -EAGAIN;
-		goto error;
+	trace_afs_flock_op(vnode, fl, afs_flock_op_set_lock);
+
+	/* AFS3 protocol only supports full-file locks and doesn't provide any
+	 * method of upgrade/downgrade, so we need to emulate for partial-file
+	 * locks.
+	 *
+	 * The OpenAFS client only gets a server lock for a full-file lock and
+	 * keeps partial-file locks local.  Allow this behaviour to be emulated
+	 * (as the default).
+	 */
+	if (mode == afs_flock_mode_local ||
+	    (partial && mode == afs_flock_mode_openafs)) {
+		no_server_lock = true;
+		goto skip_server_lock;
 	}
 
 	spin_lock(&vnode->lock);
+	list_add_tail(&fl->fl_u.afs.link, &vnode->pending_locks);
 
-	/* if we've already got a readlock on the server then we can instantly
-	 * grant another readlock, irrespective of whether there are any
-	 * pending writelocks */
-	if (type == AFS_LOCK_READ &&
-	    vnode->flags & (1 << AFS_VNODE_READLOCKED)) {
-		_debug("instant readlock");
-		ASSERTCMP(vnode->flags &
-			  ((1 << AFS_VNODE_LOCKING) |
-			   (1 << AFS_VNODE_WRITELOCKED)), ==, 0);
-		ASSERT(!list_empty(&vnode->granted_locks));
-		goto sharing_existing_lock;
-	}
+	ret = -ENOENT;
+	if (vnode->lock_state == AFS_VNODE_LOCK_DELETED)
+		goto error_unlock;
 
-	/* if there's no-one else with a lock on this vnode, then we need to
-	 * ask the server for a lock */
-	if (list_empty(&vnode->pending_locks) &&
-	    list_empty(&vnode->granted_locks)) {
-		_debug("not locked");
-		ASSERTCMP(vnode->flags &
-			  ((1 << AFS_VNODE_LOCKING) |
-			   (1 << AFS_VNODE_READLOCKED) |
-			   (1 << AFS_VNODE_WRITELOCKED)), ==, 0);
-		list_add_tail(&fl->fl_u.afs.link, &vnode->pending_locks);
-		set_bit(AFS_VNODE_LOCKING, &vnode->flags);
-		spin_unlock(&vnode->lock);
+	/* If we've already got a lock on the server then try to move to having
+	 * the VFS grant the requested lock.  Note that this means that other
+	 * clients may get starved out.
+	 */
+	_debug("try %u", vnode->lock_state);
+	if (vnode->lock_state == AFS_VNODE_LOCK_GRANTED) {
+		if (type == AFS_LOCK_READ) {
+			_debug("instant readlock");
+			list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks);
+			fl->fl_u.afs.state = AFS_LOCK_GRANTED;
+			goto vnode_is_locked_u;
+		}
 
-		ret = afs_vnode_set_lock(vnode, key, type);
-		clear_bit(AFS_VNODE_LOCKING, &vnode->flags);
-		switch (ret) {
-		case 0:
-			_debug("acquired");
-			goto acquired_server_lock;
-		case -EWOULDBLOCK:
-			_debug("would block");
-			spin_lock(&vnode->lock);
-			ASSERT(list_empty(&vnode->granted_locks));
-			ASSERTCMP(vnode->pending_locks.next, ==,
-				  &fl->fl_u.afs.link);
-			goto wait;
-		default:
-			spin_lock(&vnode->lock);
-			list_del_init(&fl->fl_u.afs.link);
-			spin_unlock(&vnode->lock);
-			goto error;
+		if (vnode->lock_type == AFS_LOCK_WRITE) {
+			_debug("instant writelock");
+			list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks);
+			fl->fl_u.afs.state = AFS_LOCK_GRANTED;
+			goto vnode_is_locked_u;
 		}
 	}
 
-	/* otherwise, we need to wait for a local lock to become available */
-	_debug("wait local");
-	list_add_tail(&fl->fl_u.afs.link, &vnode->pending_locks);
-wait:
-	if (!(fl->fl_flags & FL_SLEEP)) {
-		_debug("noblock");
+	if (vnode->lock_state == AFS_VNODE_LOCK_NONE &&
+	    !(fl->c.flc_flags & FL_SLEEP)) {
 		ret = -EAGAIN;
-		goto abort_attempt;
+		if (type == AFS_LOCK_READ) {
+			if (vnode->status.lock_count == -1)
+				goto lock_is_contended; /* Write locked */
+		} else {
+			if (vnode->status.lock_count != 0)
+				goto lock_is_contended; /* Locked */
+		}
 	}
-	spin_unlock(&vnode->lock);
 
-	/* now we need to sleep and wait for the lock manager thread to get the
-	 * lock from the server */
-	_debug("sleep");
-	ret = wait_event_interruptible(fl->fl_wait,
-				       fl->fl_u.afs.state <= AFS_LOCK_GRANTED);
-	if (fl->fl_u.afs.state <= AFS_LOCK_GRANTED) {
-		ret = fl->fl_u.afs.state;
-		if (ret < 0)
-			goto error;
-		spin_lock(&vnode->lock);
-		goto given_lock;
-	}
+	if (vnode->lock_state != AFS_VNODE_LOCK_NONE)
+		goto need_to_wait;
+
+try_to_lock:
+	/* We don't have a lock on this vnode and we aren't currently waiting
+	 * for one either, so ask the server for a lock.
+	 *
+	 * Note that we need to be careful if we get interrupted by a signal
+	 * after dispatching the request as we may still get the lock, even
+	 * though we don't wait for the reply (it's not too bad a problem - the
+	 * lock will expire in 5 mins anyway).
+	 */
+	trace_afs_flock_ev(vnode, fl, afs_flock_try_to_lock, 0);
+	vnode->lock_key = key_get(key);
+	vnode->lock_type = type;
+	afs_set_lock_state(vnode, AFS_VNODE_LOCK_SETTING);
+	spin_unlock(&vnode->lock);
 
-	/* we were interrupted, but someone may still be in the throes of
-	 * giving us the lock */
-	_debug("intr");
-	ASSERTCMP(ret, ==, -ERESTARTSYS);
+	ret = afs_set_lock(vnode, key, type); /* RPC */
 
 	spin_lock(&vnode->lock);
-	if (fl->fl_u.afs.state <= AFS_LOCK_GRANTED) {
-		ret = fl->fl_u.afs.state;
-		if (ret < 0) {
-			spin_unlock(&vnode->lock);
-			goto error;
-		}
-		goto given_lock;
-	}
+	switch (ret) {
+	case -EKEYREJECTED:
+	case -EKEYEXPIRED:
+	case -EKEYREVOKED:
+	case -EPERM:
+	case -EACCES:
+		fl->fl_u.afs.state = ret;
+		trace_afs_flock_ev(vnode, fl, afs_flock_fail_perm, ret);
+		list_del_init(&fl->fl_u.afs.link);
+		afs_next_locker(vnode, ret);
+		goto error_unlock;
 
-abort_attempt:
-	/* we aren't going to get the lock, either because we're unwilling to
-	 * wait, or because some signal happened */
-	_debug("abort");
-	if (list_empty(&vnode->granted_locks) &&
-	    vnode->pending_locks.next == &fl->fl_u.afs.link) {
-		if (vnode->pending_locks.prev != &fl->fl_u.afs.link) {
-			/* kick the next pending lock into having a go */
-			list_del_init(&fl->fl_u.afs.link);
-			afs_lock_may_be_available(vnode);
-		}
-	} else {
+	case -ENOENT:
+		fl->fl_u.afs.state = ret;
+		trace_afs_flock_ev(vnode, fl, afs_flock_fail_other, ret);
+		list_del_init(&fl->fl_u.afs.link);
+		afs_kill_lockers_enoent(vnode);
+		goto error_unlock;
+
+	default:
+		fl->fl_u.afs.state = ret;
+		trace_afs_flock_ev(vnode, fl, afs_flock_fail_other, ret);
 		list_del_init(&fl->fl_u.afs.link);
+		afs_next_locker(vnode, 0);
+		goto error_unlock;
+
+	case -EWOULDBLOCK:
+		/* The server doesn't have a lock-waiting queue, so the client
+		 * will have to retry.  The server will break the outstanding
+		 * callbacks on a file when a lock is released.
+		 */
+		ASSERT(list_empty(&vnode->granted_locks));
+		ASSERTCMP(vnode->pending_locks.next, ==, &fl->fl_u.afs.link);
+		goto lock_is_contended;
+
+	case 0:
+		afs_set_lock_state(vnode, AFS_VNODE_LOCK_GRANTED);
+		trace_afs_flock_ev(vnode, fl, afs_flock_acquired, type);
+		afs_grant_locks(vnode);
+		goto vnode_is_locked_u;
 	}
-	spin_unlock(&vnode->lock);
-	goto error;
 
-acquired_server_lock:
-	/* we've acquired a server lock, but it needs to be renewed after 5
-	 * mins */
-	spin_lock(&vnode->lock);
-	afs_schedule_lock_extension(vnode);
-	if (type == AFS_LOCK_READ)
-		set_bit(AFS_VNODE_READLOCKED, &vnode->flags);
-	else
-		set_bit(AFS_VNODE_WRITELOCKED, &vnode->flags);
-sharing_existing_lock:
-	/* the lock has been granted as far as we're concerned... */
-	fl->fl_u.afs.state = AFS_LOCK_GRANTED;
-	list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks);
-given_lock:
-	/* ... but we do still need to get the VFS's blessing */
-	ASSERT(!(vnode->flags & (1 << AFS_VNODE_LOCKING)));
-	ASSERT((vnode->flags & ((1 << AFS_VNODE_READLOCKED) |
-				(1 << AFS_VNODE_WRITELOCKED))) != 0);
-	ret = posix_lock_file(file, fl, NULL);
+vnode_is_locked_u:
+	spin_unlock(&vnode->lock);
+vnode_is_locked:
+	/* the lock has been granted by the server... */
+	ASSERTCMP(fl->fl_u.afs.state, ==, AFS_LOCK_GRANTED);
+
+skip_server_lock:
+	/* ... but the VFS still needs to distribute access on this client. */
+	trace_afs_flock_ev(vnode, fl, afs_flock_vfs_locking, 0);
+	ret = locks_lock_file_wait(file, fl);
+	trace_afs_flock_ev(vnode, fl, afs_flock_vfs_lock, ret);
 	if (ret < 0)
 		goto vfs_rejected_lock;
-	spin_unlock(&vnode->lock);
 
-	/* again, make sure we've got a callback on this file and, again, make
+	/* Again, make sure we've got a callback on this file and, again, make
 	 * sure that our view of the data version is up to date (we ignore
-	 * errors incurred here and deal with the consequences elsewhere) */
-	afs_vnode_fetch_status(vnode, NULL, key);
+	 * errors incurred here and deal with the consequences elsewhere).
+	 */
+	afs_validate(vnode, key);
+	_leave(" = 0");
+	return 0;
 
-error:
-	spin_unlock(&inode->i_lock);
-	_leave(" = %d", ret);
-	return ret;
+lock_is_contended:
+	if (!(fl->c.flc_flags & FL_SLEEP)) {
+		list_del_init(&fl->fl_u.afs.link);
+		afs_next_locker(vnode, 0);
+		ret = -EAGAIN;
+		goto error_unlock;
+	}
+
+	afs_set_lock_state(vnode, AFS_VNODE_LOCK_WAITING_FOR_CB);
+	trace_afs_flock_ev(vnode, fl, afs_flock_would_block, ret);
+	queue_delayed_work(afs_lock_manager, &vnode->lock_work, HZ * 5);
+
+need_to_wait:
+	/* We're going to have to wait.  Either this client doesn't have a lock
+	 * on the server yet and we need to wait for a callback to occur, or
+	 * the client does have a lock on the server, but it's shared and we
+	 * need an exclusive lock.
+	 */
+	spin_unlock(&vnode->lock);
+
+	trace_afs_flock_ev(vnode, fl, afs_flock_waiting, 0);
+	ret = wait_event_interruptible(fl->c.flc_wait,
+				       fl->fl_u.afs.state != AFS_LOCK_PENDING);
+	trace_afs_flock_ev(vnode, fl, afs_flock_waited, ret);
+
+	if (fl->fl_u.afs.state >= 0 && fl->fl_u.afs.state != AFS_LOCK_GRANTED) {
+		spin_lock(&vnode->lock);
+
+		switch (fl->fl_u.afs.state) {
+		case AFS_LOCK_YOUR_TRY:
+			fl->fl_u.afs.state = AFS_LOCK_PENDING;
+			goto try_to_lock;
+		case AFS_LOCK_PENDING:
+			if (ret > 0) {
+				/* We need to retry the lock.  We may not be
+				 * notified by the server if it just expired
+				 * rather than being released.
+				 */
+				ASSERTCMP(vnode->lock_state, ==, AFS_VNODE_LOCK_WAITING_FOR_CB);
+				afs_set_lock_state(vnode, AFS_VNODE_LOCK_SETTING);
+				fl->fl_u.afs.state = AFS_LOCK_PENDING;
+				goto try_to_lock;
+			}
+			goto error_unlock;
+		case AFS_LOCK_GRANTED:
+		default:
+			break;
+		}
+
+		spin_unlock(&vnode->lock);
+	}
+
+	if (fl->fl_u.afs.state == AFS_LOCK_GRANTED)
+		goto vnode_is_locked;
+	ret = fl->fl_u.afs.state;
+	goto error;
 
 vfs_rejected_lock:
-	/* the VFS rejected the lock we just obtained, so we have to discard
-	 * what we just got */
+	/* The VFS rejected the lock we just obtained, so we have to discard
+	 * what we just got.  We defer this to the lock manager work item to
+	 * deal with.
+	 */
 	_debug("vfs refused %d", ret);
+	if (no_server_lock)
+		goto error;
+	spin_lock(&vnode->lock);
 	list_del_init(&fl->fl_u.afs.link);
-	if (list_empty(&vnode->granted_locks))
-		afs_defer_unlock(vnode, key);
-	goto abort_attempt;
+	afs_defer_unlock(vnode);
+
+error_unlock:
+	spin_unlock(&vnode->lock);
+error:
+	_leave(" = %d", ret);
+	return ret;
 }
 
 /*
@@ -440,34 +700,20 @@ vfs_rejected_lock:
  */
 static int afs_do_unlk(struct file *file, struct file_lock *fl)
 {
-	struct afs_vnode *vnode = AFS_FS_I(file->f_mapping->host);
-	struct key *key = file->private_data;
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
 	int ret;
 
-	_enter("{%x:%u},%u", vnode->fid.vid, vnode->fid.vnode, fl->fl_type);
+	_enter("{%llx:%llu},%u", vnode->fid.vid, vnode->fid.vnode,
+	       fl->c.flc_type);
 
-	/* only whole-file unlocks are supported */
-	if (fl->fl_start != 0 || fl->fl_end != OFFSET_MAX)
-		return -EINVAL;
+	trace_afs_flock_op(vnode, fl, afs_flock_op_unlock);
 
-	fl->fl_ops = &afs_lock_ops;
-	INIT_LIST_HEAD(&fl->fl_u.afs.link);
-	fl->fl_u.afs.state = AFS_LOCK_PENDING;
+	/* Flush all pending writes before doing anything with locks. */
+	vfs_fsync(file, 0);
 
-	spin_lock(&vnode->lock);
-	ret = posix_lock_file(file, fl, NULL);
-	if (ret < 0) {
-		spin_unlock(&vnode->lock);
-		_leave(" = %d [vfs]", ret);
-		return ret;
-	}
-
-	/* discard the server lock only if all granted locks are gone */
-	if (list_empty(&vnode->granted_locks))
-		afs_defer_unlock(vnode, key);
-	spin_unlock(&vnode->lock);
-	_leave(" = 0");
-	return 0;
+	ret = locks_lock_file_wait(file, fl);
+	_leave(" = %d [%u]", ret, vnode->lock_state);
+	return ret;
 }
 
 /*
@@ -475,38 +721,40 @@ static int afs_do_unlk(struct file *file, struct file_lock *fl)
  */
 static int afs_do_getlk(struct file *file, struct file_lock *fl)
 {
-	struct afs_vnode *vnode = AFS_FS_I(file->f_mapping->host);
-	struct key *key = file->private_data;
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
+	struct key *key = afs_file_key(file);
 	int ret, lock_count;
 
 	_enter("");
 
-	fl->fl_type = F_UNLCK;
+	if (vnode->lock_state == AFS_VNODE_LOCK_DELETED)
+		return -ENOENT;
 
-	mutex_lock(&vnode->vfs_inode.i_mutex);
+	fl->c.flc_type = F_UNLCK;
 
 	/* check local lock records first */
-	ret = 0;
 	posix_test_lock(file, fl);
-	if (fl->fl_type == F_UNLCK) {
+	if (lock_is_unlock(fl)) {
 		/* no local locks; consult the server */
-		ret = afs_vnode_fetch_status(vnode, NULL, key);
+		ret = afs_fetch_status(vnode, key, false, NULL);
 		if (ret < 0)
 			goto error;
-		lock_count = vnode->status.lock_count;
-		if (lock_count) {
+
+		lock_count = READ_ONCE(vnode->status.lock_count);
+		if (lock_count != 0) {
 			if (lock_count > 0)
-				fl->fl_type = F_RDLCK;
+				fl->c.flc_type = F_RDLCK;
 			else
-				fl->fl_type = F_WRLCK;
+				fl->c.flc_type = F_WRLCK;
 			fl->fl_start = 0;
 			fl->fl_end = OFFSET_MAX;
+			fl->c.flc_pid = 0;
 		}
 	}
 
+	ret = 0;
 error:
-	mutex_unlock(&vnode->vfs_inode.i_mutex);
-	_leave(" = %d [%hd]", ret, fl->fl_type);
+	_leave(" = %d [%hd]", ret, fl->c.flc_type);
 	return ret;
 }
 
@@ -516,21 +764,33 @@ error:
 int afs_lock(struct file *file, int cmd, struct file_lock *fl)
 {
 	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
+	enum afs_flock_operation op;
+	int ret;
 
-	_enter("{%x:%u},%d,{t=%x,fl=%x,r=%Ld:%Ld}",
+	_enter("{%llx:%llu},%d,{t=%x,fl=%x,r=%Ld:%Ld}",
 	       vnode->fid.vid, vnode->fid.vnode, cmd,
-	       fl->fl_type, fl->fl_flags,
+	       fl->c.flc_type, fl->c.flc_flags,
 	       (long long) fl->fl_start, (long long) fl->fl_end);
 
-	/* AFS doesn't support mandatory locks */
-	if (__mandatory_lock(&vnode->vfs_inode) && fl->fl_type != F_UNLCK)
-		return -ENOLCK;
-
 	if (IS_GETLK(cmd))
 		return afs_do_getlk(file, fl);
-	if (fl->fl_type == F_UNLCK)
-		return afs_do_unlk(file, fl);
-	return afs_do_setlk(file, fl);
+
+	fl->fl_u.afs.debug_id = atomic_inc_return(&afs_file_lock_debug_id);
+	trace_afs_flock_op(vnode, fl, afs_flock_op_lock);
+
+	if (lock_is_unlock(fl))
+		ret = afs_do_unlk(file, fl);
+	else
+		ret = afs_do_setlk(file, fl);
+
+	switch (ret) {
+	case 0:		op = afs_flock_op_return_ok; break;
+	case -EAGAIN:	op = afs_flock_op_return_eagain; break;
+	case -EDEADLK:	op = afs_flock_op_return_edeadlk; break;
+	default:	op = afs_flock_op_return_error; break;
+	}
+	trace_afs_flock_op(vnode, fl, op);
+	return ret;
 }
 
 /*
@@ -539,10 +799,12 @@ int afs_lock(struct file *file, int cmd, struct file_lock *fl)
 int afs_flock(struct file *file, int cmd, struct file_lock *fl)
 {
 	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
+	enum afs_flock_operation op;
+	int ret;
 
-	_enter("{%x:%u},%d,{t=%x,fl=%x}",
+	_enter("{%llx:%llu},%d,{t=%x,fl=%x}",
 	       vnode->fid.vid, vnode->fid.vnode, cmd,
-	       fl->fl_type, fl->fl_flags);
+	       fl->c.flc_type, fl->c.flc_flags);
 
 	/*
 	 * No BSD flocks over NFS allowed.
@@ -551,17 +813,26 @@ int afs_flock(struct file *file, int cmd, struct file_lock *fl)
 	 * Not sure whether that would be unique, though, or whether
 	 * that would break in other places.
 	 */
-	if (!(fl->fl_flags & FL_FLOCK))
+	if (!(fl->c.flc_flags & FL_FLOCK))
 		return -ENOLCK;
 
+	fl->fl_u.afs.debug_id = atomic_inc_return(&afs_file_lock_debug_id);
+	trace_afs_flock_op(vnode, fl, afs_flock_op_flock);
+
 	/* we're simulating flock() locks using posix locks on the server */
-	fl->fl_owner = (fl_owner_t) file;
-	fl->fl_start = 0;
-	fl->fl_end = OFFSET_MAX;
+	if (lock_is_unlock(fl))
+		ret = afs_do_unlk(file, fl);
+	else
+		ret = afs_do_setlk(file, fl);
 
-	if (fl->fl_type == F_UNLCK)
-		return afs_do_unlk(file, fl);
-	return afs_do_setlk(file, fl);
+	switch (ret) {
+	case 0:		op = afs_flock_op_return_ok; break;
+	case -EAGAIN:	op = afs_flock_op_return_eagain; break;
+	case -EDEADLK:	op = afs_flock_op_return_edeadlk; break;
+	default:	op = afs_flock_op_return_error; break;
+	}
+	trace_afs_flock_op(vnode, fl, op);
+	return ret;
 }
 
 /*
@@ -572,9 +843,16 @@ int afs_flock(struct file *file, int cmd, struct file_lock *fl)
  */
 static void afs_fl_copy_lock(struct file_lock *new, struct file_lock *fl)
 {
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(fl->c.flc_file));
+
 	_enter("");
 
+	new->fl_u.afs.debug_id = atomic_inc_return(&afs_file_lock_debug_id);
+
+	spin_lock(&vnode->lock);
+	trace_afs_flock_op(vnode, new, afs_flock_op_copy_lock);
 	list_add(&new->fl_u.afs.link, &fl->fl_u.afs.link);
+	spin_unlock(&vnode->lock);
 }
 
 /*
@@ -583,7 +861,17 @@ static void afs_fl_copy_lock(struct file_lock *new, struct file_lock *fl)
  */
 static void afs_fl_release_private(struct file_lock *fl)
 {
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(fl->c.flc_file));
+
 	_enter("");
 
+	spin_lock(&vnode->lock);
+
+	trace_afs_flock_op(vnode, fl, afs_flock_op_release_lock);
 	list_del_init(&fl->fl_u.afs.link);
+	if (list_empty(&vnode->granted_locks))
+		afs_defer_unlock(vnode);
+
+	_debug("state %u for %p", vnode->lock_state, vnode);
+	spin_unlock(&vnode->lock);
 }