8 files changed, 156 insertions, 135 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 72f8e1311392..0176241eaea7 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2738,15 +2738,13 @@ int ceph_get_caps(struct ceph_inode_info *ci, int need, int want,
 		_got = 0;
 		ret = try_get_cap_refs(ci, need, want, endoff,
 				       false, &_got);
-		if (ret == -EAGAIN) {
+		if (ret == -EAGAIN)
 			continue;
-		} else if (!ret) {
-			int err;
-
+		if (!ret) {
 			DEFINE_WAIT_FUNC(wait, woken_wake_function);
 			add_wait_queue(&ci->i_cap_wq, &wait);
 
-			while (!(err = try_get_cap_refs(ci, need, want, endoff,
+			while (!(ret = try_get_cap_refs(ci, need, want, endoff,
 							true, &_got))) {
 				if (signal_pending(current)) {
 					ret = -ERESTARTSYS;
@@ -2756,14 +2754,16 @@ int ceph_get_caps(struct ceph_inode_info *ci, int need, int want,
 			}
 
 			remove_wait_queue(&ci->i_cap_wq, &wait);
-			if (err == -EAGAIN)
+			if (ret == -EAGAIN)
 				continue;
 		}
-		if (ret == -ESTALE) {
-			/* session was killed, try renew caps */
-			ret = ceph_renew_caps(&ci->vfs_inode);
-			if (ret == 0)
-				continue;
+		if (ret < 0) {
+			if (ret == -ESTALE) {
+				/* session was killed, try renew caps */
+				ret = ceph_renew_caps(&ci->vfs_inode);
+				if (ret == 0)
+					continue;
+			}
 			return ret;
 		}
 
@@ -2992,8 +2992,10 @@ void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
 	}
 	if (complete_capsnap)
 		wake_up_all(&ci->i_cap_wq);
-	while (put-- > 0)
-		iput(inode);
+	while (put-- > 0) {
+		/* avoid calling iput_final() in osd dispatch threads */
+		ceph_async_iput(inode);
+	}
 }
 
 /*
@@ -3964,8 +3966,9 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 done:
 	mutex_unlock(&session->s_mutex);
 done_unlocked:
-	iput(inode);
 	ceph_put_string(extra_info.pool_ns);
+	/* avoid calling iput_final() in mds dispatch threads */
+	ceph_async_iput(inode);
 	return;
 
 flush_cap_releases:
@@ -4011,7 +4014,8 @@ void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
 		if (inode) {
 			dout("check_delayed_caps on %p\n", inode);
 			ceph_check_caps(ci, flags, NULL);
-			iput(inode);
+			/* avoid calling iput_final() in tick thread */
+			ceph_async_iput(inode);
 		}
 	}
 	spin_unlock(&mdsc->cap_delay_lock);
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 305daf043eb0..183c37c0a8fc 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -791,7 +791,7 @@ static void ceph_aio_complete_req(struct ceph_osd_request *req)
 		if (aio_work) {
 			INIT_WORK(&aio_work->work, ceph_aio_retry_work);
 			aio_work->req = req;
-			queue_work(ceph_inode_to_client(inode)->wb_wq,
+			queue_work(ceph_inode_to_client(inode)->inode_wq,
 				   &aio_work->work);
 			return;
 		}
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index f85355bf49c4..761451f36e2d 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -33,9 +33,7 @@
 
 static const struct inode_operations ceph_symlink_iops;
 
-static void ceph_invalidate_work(struct work_struct *work);
-static void ceph_writeback_work(struct work_struct *work);
-static void ceph_vmtruncate_work(struct work_struct *work);
+static void ceph_inode_work(struct work_struct *work);
 
 /*
  * find or create an inode, given the ceph ino number
@@ -509,10 +507,8 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
 	INIT_LIST_HEAD(&ci->i_snap_realm_item);
 	INIT_LIST_HEAD(&ci->i_snap_flush_item);
 
-	INIT_WORK(&ci->i_wb_work, ceph_writeback_work);
-	INIT_WORK(&ci->i_pg_inv_work, ceph_invalidate_work);
-
-	INIT_WORK(&ci->i_vmtruncate_work, ceph_vmtruncate_work);
+	INIT_WORK(&ci->i_work, ceph_inode_work);
+	ci->i_work_mask = 0;
 
 	ceph_fscache_inode_init(ci);
 
@@ -1480,7 +1476,8 @@ static int readdir_prepopulate_inodes_only(struct ceph_mds_request *req,
 			pr_err("fill_inode badness on %p got %d\n", in, rc);
 			err = rc;
 		}
-		iput(in);
+		/* avoid calling iput_final() in mds dispatch threads */
+		ceph_async_iput(in);
 	}
 
 	return err;
@@ -1678,8 +1675,11 @@ retry_lookup:
 				 &req->r_caps_reservation);
 		if (ret < 0) {
 			pr_err("fill_inode badness on %p\n", in);
-			if (d_really_is_negative(dn))
-				iput(in);
+			if (d_really_is_negative(dn)) {
+				/* avoid calling iput_final() in mds
+				 * dispatch threads */
+				ceph_async_iput(in);
+			}
 			d_drop(dn);
 			err = ret;
 			goto next_item;
@@ -1689,7 +1689,7 @@ retry_lookup:
 			if (ceph_security_xattr_deadlock(in)) {
 				dout(" skip splicing dn %p to inode %p"
 				     " (security xattr deadlock)\n", dn, in);
-				iput(in);
+				ceph_async_iput(in);
 				skipped++;
 				goto next_item;
 			}
@@ -1741,56 +1741,86 @@ bool ceph_inode_set_size(struct inode *inode, loff_t size)
 }
 
 /*
+ * Put reference to inode, but avoid calling iput_final() in current thread.
+ * iput_final() may wait for reahahead pages. The wait can cause deadlock in
+ * some contexts.
+ */
+void ceph_async_iput(struct inode *inode)
+{
+	if (!inode)
+		return;
+	for (;;) {
+		if (atomic_add_unless(&inode->i_count, -1, 1))
+			break;
+		if (queue_work(ceph_inode_to_client(inode)->inode_wq,
+			       &ceph_inode(inode)->i_work))
+			break;
+		/* queue work failed, i_count must be at least 2 */
+	}
+}
+
+/*
  * Write back inode data in a worker thread.  (This can't be done
  * in the message handler context.)
  */
 void ceph_queue_writeback(struct inode *inode)
 {
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	set_bit(CEPH_I_WORK_WRITEBACK, &ci->i_work_mask);
+
 	ihold(inode);
-	if (queue_work(ceph_inode_to_client(inode)->wb_wq,
-		       &ceph_inode(inode)->i_wb_work)) {
+	if (queue_work(ceph_inode_to_client(inode)->inode_wq,
+		       &ci->i_work)) {
 		dout("ceph_queue_writeback %p\n", inode);
 	} else {
-		dout("ceph_queue_writeback %p failed\n", inode);
+		dout("ceph_queue_writeback %p already queued, mask=%lx\n",
+		     inode, ci->i_work_mask);
 		iput(inode);
 	}
 }
 
-static void ceph_writeback_work(struct work_struct *work)
-{
-	struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
-						  i_wb_work);
-	struct inode *inode = &ci->vfs_inode;
-
-	dout("writeback %p\n", inode);
-	filemap_fdatawrite(&inode->i_data);
-	iput(inode);
-}
-
 /*
  * queue an async invalidation
  */
 void ceph_queue_invalidate(struct inode *inode)
 {
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	set_bit(CEPH_I_WORK_INVALIDATE_PAGES, &ci->i_work_mask);
+
 	ihold(inode);
-	if (queue_work(ceph_inode_to_client(inode)->pg_inv_wq,
-		       &ceph_inode(inode)->i_pg_inv_work)) {
+	if (queue_work(ceph_inode_to_client(inode)->inode_wq,
+		       &ceph_inode(inode)->i_work)) {
 		dout("ceph_queue_invalidate %p\n", inode);
 	} else {
-		dout("ceph_queue_invalidate %p failed\n", inode);
+		dout("ceph_queue_invalidate %p already queued, mask=%lx\n",
+		     inode, ci->i_work_mask);
 		iput(inode);
 	}
 }
 
 /*
- * Invalidate inode pages in a worker thread.  (This can't be done
- * in the message handler context.)
+ * Queue an async vmtruncate.  If we fail to queue work, we will handle
+ * the truncation the next time we call __ceph_do_pending_vmtruncate.
  */
-static void ceph_invalidate_work(struct work_struct *work)
+void ceph_queue_vmtruncate(struct inode *inode)
 {
-	struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
-						  i_pg_inv_work);
-	struct inode *inode = &ci->vfs_inode;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	set_bit(CEPH_I_WORK_VMTRUNCATE, &ci->i_work_mask);
+
+	ihold(inode);
+	if (queue_work(ceph_inode_to_client(inode)->inode_wq,
+		       &ci->i_work)) {
+		dout("ceph_queue_vmtruncate %p\n", inode);
+	} else {
+		dout("ceph_queue_vmtruncate %p already queued, mask=%lx\n",
+		     inode, ci->i_work_mask);
+		iput(inode);
+	}
+}
+
+static void ceph_do_invalidate_pages(struct inode *inode)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 	u32 orig_gen;
 	int check = 0;
@@ -1842,44 +1872,6 @@ static void ceph_invalidate_work(struct work_struct *work)
 out:
 	if (check)
 		ceph_check_caps(ci, 0, NULL);
-	iput(inode);
-}
-
-
-/*
- * called by trunc_wq;
- *
- * We also truncate in a separate thread as well.
- */
-static void ceph_vmtruncate_work(struct work_struct *work)
-{
-	struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
-						  i_vmtruncate_work);
-	struct inode *inode = &ci->vfs_inode;
-
-	dout("vmtruncate_work %p\n", inode);
-	__ceph_do_pending_vmtruncate(inode);
-	iput(inode);
-}
-
-/*
- * Queue an async vmtruncate.  If we fail to queue work, we will handle
- * the truncation the next time we call __ceph_do_pending_vmtruncate.
- */
-void ceph_queue_vmtruncate(struct inode *inode)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-
-	ihold(inode);
-
-	if (queue_work(ceph_sb_to_client(inode->i_sb)->trunc_wq,
-		       &ci->i_vmtruncate_work)) {
-		dout("ceph_queue_vmtruncate %p\n", inode);
-	} else {
-		dout("ceph_queue_vmtruncate %p failed, pending=%d\n",
-		     inode, ci->i_truncate_pending);
-		iput(inode);
-	}
 }
 
 /*
@@ -1943,6 +1935,25 @@ retry:
 	wake_up_all(&ci->i_cap_wq);
 }
 
+static void ceph_inode_work(struct work_struct *work)
+{
+	struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
+						 i_work);
+	struct inode *inode = &ci->vfs_inode;
+
+	if (test_and_clear_bit(CEPH_I_WORK_WRITEBACK, &ci->i_work_mask)) {
+		dout("writeback %p\n", inode);
+		filemap_fdatawrite(&inode->i_data);
+	}
+	if (test_and_clear_bit(CEPH_I_WORK_INVALIDATE_PAGES, &ci->i_work_mask))
+		ceph_do_invalidate_pages(inode);
+
+	if (test_and_clear_bit(CEPH_I_WORK_VMTRUNCATE, &ci->i_work_mask))
+		__ceph_do_pending_vmtruncate(inode);
+
+	iput(inode);
+}
+
 /*
  * symlinks
  */
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 959b1bf7c327..6af2d0d4a87a 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -690,11 +690,12 @@ void ceph_mdsc_release_request(struct kref *kref)
 		ceph_msg_put(req->r_reply);
 	if (req->r_inode) {
 		ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
-		iput(req->r_inode);
+		/* avoid calling iput_final() in mds dispatch threads */
+		ceph_async_iput(req->r_inode);
 	}
 	if (req->r_parent)
 		ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
-	iput(req->r_target_inode);
+	ceph_async_iput(req->r_target_inode);
 	if (req->r_dentry)
 		dput(req->r_dentry);
 	if (req->r_old_dentry)
@@ -708,7 +709,7 @@ void ceph_mdsc_release_request(struct kref *kref)
 		 */
 		ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 				  CEPH_CAP_PIN);
-		iput(req->r_old_dentry_dir);
+		ceph_async_iput(req->r_old_dentry_dir);
 	}
 	kfree(req->r_path1);
 	kfree(req->r_path2);
@@ -818,7 +819,8 @@ static void __unregister_request(struct ceph_mds_client *mdsc,
 	}
 
 	if (req->r_unsafe_dir) {
-		iput(req->r_unsafe_dir);
+		/* avoid calling iput_final() in mds dispatch threads */
+		ceph_async_iput(req->r_unsafe_dir);
 		req->r_unsafe_dir = NULL;
 	}
 
@@ -983,7 +985,7 @@ static int __choose_mds(struct ceph_mds_client *mdsc,
 		cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 	if (!cap) {
 		spin_unlock(&ci->i_ceph_lock);
-		iput(inode);
+		ceph_async_iput(inode);
 		goto random;
 	}
 	mds = cap->session->s_mds;
@@ -992,7 +994,9 @@ static int __choose_mds(struct ceph_mds_client *mdsc,
 	     cap == ci->i_auth_cap ? "auth " : "", cap);
 	spin_unlock(&ci->i_ceph_lock);
 out:
-	iput(inode);
+	/* avoid calling iput_final() while holding mdsc->mutex or
+	 * in mds dispatch threads */
+	ceph_async_iput(inode);
 	return mds;
 
 random:
@@ -1302,7 +1306,9 @@ int ceph_iterate_session_caps(struct ceph_mds_session *session,
 		spin_unlock(&session->s_cap_lock);
 
 		if (last_inode) {
-			iput(last_inode);
+			/* avoid calling iput_final() while holding
+			 * s_mutex or in mds dispatch threads */
+			ceph_async_iput(last_inode);
 			last_inode = NULL;
 		}
 		if (old_cap) {
@@ -1335,7 +1341,7 @@ out:
 	session->s_cap_iterator = NULL;
 	spin_unlock(&session->s_cap_lock);
 
-	iput(last_inode);
+	ceph_async_iput(last_inode);
 	if (old_cap)
 		ceph_put_cap(session->s_mdsc, old_cap);
 
@@ -1471,7 +1477,8 @@ static void remove_session_caps(struct ceph_mds_session *session)
 			spin_unlock(&session->s_cap_lock);
 
 			inode = ceph_find_inode(sb, vino);
-			iput(inode);
+			 /* avoid calling iput_final() while holding s_mutex */
+			ceph_async_iput(inode);
 
 			spin_lock(&session->s_cap_lock);
 		}
@@ -3912,8 +3919,9 @@ release:
 	ceph_con_send(&session->s_con, msg);
 
 out:
-	iput(inode);
 	mutex_unlock(&session->s_mutex);
+	/* avoid calling iput_final() in mds dispatch threads */
+	ceph_async_iput(inode);
 	return;
 
 bad:
diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
index c4522212872c..d629fc857450 100644
--- a/fs/ceph/quota.c
+++ b/fs/ceph/quota.c
@@ -74,7 +74,8 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc,
 		            le64_to_cpu(h->max_files));
 	spin_unlock(&ci->i_ceph_lock);
 
-	iput(inode);
+	/* avoid calling iput_final() in dispatch thread */
+	ceph_async_iput(inode);
 }
 
 static struct ceph_quotarealm_inode *
@@ -235,7 +236,8 @@ restart:
 
 		ci = ceph_inode(in);
 		has_quota = __ceph_has_any_quota(ci);
-		iput(in);
+		/* avoid calling iput_final() while holding mdsc->snap_rwsem */
+		ceph_async_iput(in);
 
 		next = realm->parent;
 		if (has_quota || !next)
@@ -372,7 +374,8 @@ restart:
 			pr_warn("Invalid quota check op (%d)\n", op);
 			exceeded = true; /* Just break the loop */
 		}
-		iput(in);
+		/* avoid calling iput_final() while holding mdsc->snap_rwsem */
+		ceph_async_iput(in);
 
 		next = realm->parent;
 		if (exceeded || !next)
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index b26e12cd8ec3..72c6c022f02b 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -648,13 +648,15 @@ static void queue_realm_cap_snaps(struct ceph_snap_realm *realm)
 		if (!inode)
 			continue;
 		spin_unlock(&realm->inodes_with_caps_lock);
-		iput(lastinode);
+		/* avoid calling iput_final() while holding
+		 * mdsc->snap_rwsem or in mds dispatch threads */
+		ceph_async_iput(lastinode);
 		lastinode = inode;
 		ceph_queue_cap_snap(ci);
 		spin_lock(&realm->inodes_with_caps_lock);
 	}
 	spin_unlock(&realm->inodes_with_caps_lock);
-	iput(lastinode);
+	ceph_async_iput(lastinode);
 
 	dout("queue_realm_cap_snaps %p %llx done\n", realm, realm->ino);
 }
@@ -806,7 +808,9 @@ static void flush_snaps(struct ceph_mds_client *mdsc)
 		ihold(inode);
 		spin_unlock(&mdsc->snap_flush_lock);
 		ceph_flush_snaps(ci, &session);
-		iput(inode);
+		/* avoid calling iput_final() while holding
+		 * session->s_mutex or in mds dispatch threads */
+		ceph_async_iput(inode);
 		spin_lock(&mdsc->snap_flush_lock);
 	}
 	spin_unlock(&mdsc->snap_flush_lock);
@@ -950,12 +954,14 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc,
 			ceph_get_snap_realm(mdsc, realm);
 			ceph_put_snap_realm(mdsc, oldrealm);
 
-			iput(inode);
+			/* avoid calling iput_final() while holding
+			 * mdsc->snap_rwsem or mds in dispatch threads */
+			ceph_async_iput(inode);
 			continue;
 
 skip_inode:
 			spin_unlock(&ci->i_ceph_lock);
-			iput(inode);
+			ceph_async_iput(inode);
 		}
 
 		/* we may have taken some of the old realm's children. */
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 01be7c1bc4c6..d57fa60dcd43 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -672,18 +672,12 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
 	 * The number of concurrent works can be high but they don't need
 	 * to be processed in parallel, limit concurrency.
 	 */
-	fsc->wb_wq = alloc_workqueue("ceph-writeback", 0, 1);
-	if (!fsc->wb_wq)
+	fsc->inode_wq = alloc_workqueue("ceph-inode", WQ_UNBOUND, 0);
+	if (!fsc->inode_wq)
 		goto fail_client;
-	fsc->pg_inv_wq = alloc_workqueue("ceph-pg-invalid", 0, 1);
-	if (!fsc->pg_inv_wq)
-		goto fail_wb_wq;
-	fsc->trunc_wq = alloc_workqueue("ceph-trunc", 0, 1);
-	if (!fsc->trunc_wq)
-		goto fail_pg_inv_wq;
 	fsc->cap_wq = alloc_workqueue("ceph-cap", 0, 1);
 	if (!fsc->cap_wq)
-		goto fail_trunc_wq;
+		goto fail_inode_wq;
 
 	/* set up mempools */
 	err = -ENOMEM;
@@ -697,12 +691,8 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
 
 fail_cap_wq:
 	destroy_workqueue(fsc->cap_wq);
-fail_trunc_wq:
-	destroy_workqueue(fsc->trunc_wq);
-fail_pg_inv_wq:
-	destroy_workqueue(fsc->pg_inv_wq);
-fail_wb_wq:
-	destroy_workqueue(fsc->wb_wq);
+fail_inode_wq:
+	destroy_workqueue(fsc->inode_wq);
 fail_client:
 	ceph_destroy_client(fsc->client);
 fail:
@@ -715,9 +705,7 @@ fail:
 
 static void flush_fs_workqueues(struct ceph_fs_client *fsc)
 {
-	flush_workqueue(fsc->wb_wq);
-	flush_workqueue(fsc->pg_inv_wq);
-	flush_workqueue(fsc->trunc_wq);
+	flush_workqueue(fsc->inode_wq);
 	flush_workqueue(fsc->cap_wq);
 }
 
@@ -725,9 +713,7 @@ static void destroy_fs_client(struct ceph_fs_client *fsc)
 {
 	dout("destroy_fs_client %p\n", fsc);
 
-	destroy_workqueue(fsc->wb_wq);
-	destroy_workqueue(fsc->pg_inv_wq);
-	destroy_workqueue(fsc->trunc_wq);
+	destroy_workqueue(fsc->inode_wq);
 	destroy_workqueue(fsc->cap_wq);
 
 	mempool_destroy(fsc->wb_pagevec_pool);
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 6edab9a750f8..5f27e1f7f2d6 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -109,9 +109,7 @@ struct ceph_fs_client {
 	mempool_t *wb_pagevec_pool;
 	atomic_long_t writeback_count;
 
-	struct workqueue_struct *wb_wq;
-	struct workqueue_struct *pg_inv_wq;
-	struct workqueue_struct *trunc_wq;
+	struct workqueue_struct *inode_wq;
 	struct workqueue_struct *cap_wq;
 
 #ifdef CONFIG_DEBUG_FS
@@ -387,10 +385,8 @@ struct ceph_inode_info {
 	struct list_head i_snap_realm_item;
 	struct list_head i_snap_flush_item;
 
-	struct work_struct i_wb_work;  /* writeback work */
-	struct work_struct i_pg_inv_work;  /* page invalidation work */
-
-	struct work_struct i_vmtruncate_work;
+	struct work_struct i_work;
+	unsigned long  i_work_mask;
 
 #ifdef CONFIG_CEPH_FSCACHE
 	struct fscache_cookie *fscache;
@@ -513,6 +509,13 @@ static inline struct inode *ceph_find_inode(struct super_block *sb,
 
 
 /*
+ * Masks of ceph inode work.
+ */
+#define CEPH_I_WORK_WRITEBACK		0 /* writeback */
+#define CEPH_I_WORK_INVALIDATE_PAGES	1 /* invalidate pages */
+#define CEPH_I_WORK_VMTRUNCATE		2 /* vmtruncate */
+
+/*
  * We set the ERROR_WRITE bit when we start seeing write errors on an inode
  * and then clear it when they start succeeding. Note that we do a lockless
  * check first, and only take the lock if it looks like it needs to be changed.
@@ -896,9 +899,9 @@ extern int ceph_inode_holds_cap(struct inode *inode, int mask);
 extern bool ceph_inode_set_size(struct inode *inode, loff_t size);
 extern void __ceph_do_pending_vmtruncate(struct inode *inode);
 extern void ceph_queue_vmtruncate(struct inode *inode);
-
 extern void ceph_queue_invalidate(struct inode *inode);
 extern void ceph_queue_writeback(struct inode *inode);
+extern void ceph_async_iput(struct inode *inode);
 
 extern int __ceph_do_getattr(struct inode *inode, struct page *locked_page,
 			     int mask, bool force);