Merge tag 'v5.2-rc4' into media/master

There are some conflicts due to SPDX changes. We also have more
patches being merged via media tree touching them.

So, let's merge back from upstream and address those.

Linux 5.2-rc4

* tag 'v5.2-rc4': (767 commits)
  Linux 5.2-rc4
  MAINTAINERS: Karthikeyan Ramasubramanian is MIA
  i2c: xiic: Add max_read_len quirk
  lockref: Limit number of cmpxchg loop retries
  uaccess: add noop untagged_addr definition
  x86/insn-eval: Fix use-after-free access to LDT entry
  kbuild: use more portable 'command -v' for cc-cross-prefix
  s390/unwind: correct stack switching during unwind
  block, bfq: add weight symlink to the bfq.weight cgroup parameter
  cgroup: let a symlink too be created with a cftype file
  drm/nouveau/secboot/gp10[2467]: support newer FW to fix SEC2 failures on some boards
  drm/nouveau/secboot: enable loading of versioned LS PMU/SEC2 ACR msgqueue FW
  drm/nouveau/secboot: split out FW version-specific LS function pointers
  drm/nouveau/secboot: pass max supported FW version to LS load funcs
  drm/nouveau/core: support versioned firmware loading
  drm/nouveau/core: pass subdev into nvkm_firmware_get, rather than device
  block: free sched's request pool in blk_cleanup_queue
  pktgen: do not sleep with the thread lock held.
  net: mvpp2: Use strscpy to handle stat strings
  net: rds: fix memory leak in rds_ib_flush_mr_pool
  ...

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

11 files changed, 159 insertions, 181 deletions

diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
index 5f0103f40079..8a19c249036c 100644
--- a/fs/ceph/acl.c
+++ b/fs/ceph/acl.c
@@ -1,21 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/fs/ceph/acl.c
  *
  * Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
  */
 
 #include <linux/ceph/ceph_debug.h>
diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c
index 1bf3502bdd6f..bc90cf6ad7ed 100644
--- a/fs/ceph/cache.c
+++ b/fs/ceph/cache.c
@@ -1,24 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Ceph cache definitions.
  *
  *  Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
  *  Written by Milosz Tanski (milosz@adfin.com)
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License version 2
- *  as published by the Free Software Foundation.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to:
- *  Free Software Foundation
- *  51 Franklin Street, Fifth Floor
- *  Boston, MA  02111-1301  USA
- *
  */
 
 #include "super.h"
diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index 7e72c7594f0c..e486fac3434d 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -1,24 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Ceph cache definitions.
  *
  *  Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
  *  Written by Milosz Tanski (milosz@adfin.com)
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License version 2
- *  as published by the Free Software Foundation.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to:
- *  Free Software Foundation
- *  51 Franklin Street, Fifth Floor
- *  Boston, MA  02111-1301  USA
- *
  */
 
 #ifndef _CEPH_CACHE_H
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);