diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 5598a0d02295..4cfce1ee31fa 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -87,7 +87,7 @@ static int ceph_set_page_dirty(struct page *page)
 
 	/* dirty the head */
 	spin_lock(&inode->i_lock);
-	if (ci->i_wrbuffer_ref_head == 0)
+	if (ci->i_head_snapc == NULL)
 		ci->i_head_snapc = ceph_get_snap_context(snapc);
 	++ci->i_wrbuffer_ref_head;
 	if (ci->i_wrbuffer_ref == 0)
@@ -105,13 +105,7 @@ static int ceph_set_page_dirty(struct page *page)
 	spin_lock_irq(&mapping->tree_lock);
 	if (page->mapping) {	/* Race with truncate? */
 		WARN_ON_ONCE(!PageUptodate(page));
-
-		if (mapping_cap_account_dirty(mapping)) {
-			__inc_zone_page_state(page, NR_FILE_DIRTY);
-			__inc_bdi_stat(mapping->backing_dev_info,
-					BDI_RECLAIMABLE);
-			task_io_account_write(PAGE_CACHE_SIZE);
-		}
+		account_page_dirtied(page, page->mapping);
 		radix_tree_tag_set(&mapping->page_tree,
 				page_index(page), PAGECACHE_TAG_DIRTY);
 
@@ -352,7 +346,7 @@ static struct ceph_snap_context *get_oldest_context(struct inode *inode,
 			break;
 		}
 	}
-	if (!snapc && ci->i_head_snapc) {
+	if (!snapc && ci->i_wrbuffer_ref_head) {
 		snapc = ceph_get_snap_context(ci->i_head_snapc);
 		dout(" head snapc %p has %d dirty pages\n",
 		     snapc, ci->i_wrbuffer_ref_head);
diff --git a/fs/ceph/auth_x.c b/fs/ceph/auth_x.c
index 582e0b2caf8a..a2d002cbdec2 100644
--- a/fs/ceph/auth_x.c
+++ b/fs/ceph/auth_x.c
@@ -376,7 +376,7 @@ static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
 
 		th = get_ticket_handler(ac, service);
 
-		if (!th) {
+		if (IS_ERR(th)) {
 			*pneed |= service;
 			continue;
 		}
@@ -399,6 +399,9 @@ static int ceph_x_build_request(struct ceph_auth_client *ac,
 	struct ceph_x_ticket_handler *th =
 		get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
 
+	if (IS_ERR(th))
+		return PTR_ERR(th);
+
 	ceph_x_validate_tickets(ac, &need);
 
 	dout("build_request want %x have %x need %x\n",
@@ -450,7 +453,6 @@ static int ceph_x_build_request(struct ceph_auth_client *ac,
 			return -ERANGE;
 		head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
 
-		BUG_ON(!th);
 		ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
 		if (ret)
 			return ret;
@@ -505,7 +507,8 @@ static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
 
 	case CEPHX_GET_PRINCIPAL_SESSION_KEY:
 		th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
-		BUG_ON(!th);
+		if (IS_ERR(th))
+			return PTR_ERR(th);
 		ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
 					       buf + sizeof(*head), end);
 		break;
@@ -563,8 +566,8 @@ static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
 	void *end = p + sizeof(au->reply_buf);
 
 	th = get_ticket_handler(ac, au->service);
-	if (!th)
-		return -EIO;  /* hrm! */
+	if (IS_ERR(th))
+		return PTR_ERR(th);
 	ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply));
 	if (ret < 0)
 		return ret;
@@ -626,7 +629,7 @@ static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
 	struct ceph_x_ticket_handler *th;
 
 	th = get_ticket_handler(ac, peer_type);
-	if (th && !IS_ERR(th))
+	if (!IS_ERR(th))
 		remove_ticket_handler(ac, th);
 }
 
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 7bf182b03973..a2069b6680ae 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1082,6 +1082,7 @@ static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
 	gid_t gid;
 	struct ceph_mds_session *session;
 	u64 xattr_version = 0;
+	struct ceph_buffer *xattr_blob = NULL;
 	int delayed = 0;
 	u64 flush_tid = 0;
 	int i;
@@ -1142,6 +1143,10 @@ static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
 		for (i = 0; i < CEPH_CAP_BITS; i++)
 			if (flushing & (1 << i))
 				ci->i_cap_flush_tid[i] = flush_tid;
+
+		follows = ci->i_head_snapc->seq;
+	} else {
+		follows = 0;
 	}
 
 	keep = cap->implemented;
@@ -1155,14 +1160,14 @@ static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
 	mtime = inode->i_mtime;
 	atime = inode->i_atime;
 	time_warp_seq = ci->i_time_warp_seq;
-	follows = ci->i_snap_realm->cached_context->seq;
 	uid = inode->i_uid;
 	gid = inode->i_gid;
 	mode = inode->i_mode;
 
-	if (dropping & CEPH_CAP_XATTR_EXCL) {
+	if (flushing & CEPH_CAP_XATTR_EXCL) {
 		__ceph_build_xattrs_blob(ci);
-		xattr_version = ci->i_xattrs.version + 1;
+		xattr_blob = ci->i_xattrs.blob;
+		xattr_version = ci->i_xattrs.version;
 	}
 
 	spin_unlock(&inode->i_lock);
@@ -1170,9 +1175,7 @@ static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
 	ret = send_cap_msg(session, ceph_vino(inode).ino, cap_id,
 		op, keep, want, flushing, seq, flush_tid, issue_seq, mseq,
 		size, max_size, &mtime, &atime, time_warp_seq,
-		uid, gid, mode,
-		xattr_version,
-		(flushing & CEPH_CAP_XATTR_EXCL) ? ci->i_xattrs.blob : NULL,
+		uid, gid, mode, xattr_version, xattr_blob,
 		follows);
 	if (ret < 0) {
 		dout("error sending cap msg, must requeue %p\n", inode);
@@ -1282,7 +1285,7 @@ retry:
 			     &capsnap->mtime, &capsnap->atime,
 			     capsnap->time_warp_seq,
 			     capsnap->uid, capsnap->gid, capsnap->mode,
-			     0, NULL,
+			     capsnap->xattr_version, capsnap->xattr_blob,
 			     capsnap->follows);
 
 		next_follows = capsnap->follows + 1;
@@ -1332,7 +1335,11 @@ void __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
 	     ceph_cap_string(was | mask));
 	ci->i_dirty_caps |= mask;
 	if (was == 0) {
-		dout(" inode %p now dirty\n", &ci->vfs_inode);
+		if (!ci->i_head_snapc)
+			ci->i_head_snapc = ceph_get_snap_context(
+				ci->i_snap_realm->cached_context);
+		dout(" inode %p now dirty snapc %p\n", &ci->vfs_inode,
+			ci->i_head_snapc);
 		BUG_ON(!list_empty(&ci->i_dirty_item));
 		spin_lock(&mdsc->cap_dirty_lock);
 		list_add(&ci->i_dirty_item, &mdsc->cap_dirty);
@@ -2190,7 +2197,9 @@ void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
 
 	if (ci->i_head_snapc == snapc) {
 		ci->i_wrbuffer_ref_head -= nr;
-		if (!ci->i_wrbuffer_ref_head) {
+		if (ci->i_wrbuffer_ref_head == 0 &&
+		    ci->i_dirty_caps == 0 && ci->i_flushing_caps == 0) {
+			BUG_ON(!ci->i_head_snapc);
 			ceph_put_snap_context(ci->i_head_snapc);
 			ci->i_head_snapc = NULL;
 		}
@@ -2483,6 +2492,11 @@ static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid,
 			dout(" inode %p now clean\n", inode);
 			BUG_ON(!list_empty(&ci->i_dirty_item));
 			drop = 1;
+			if (ci->i_wrbuffer_ref_head == 0) {
+				BUG_ON(!ci->i_head_snapc);
+				ceph_put_snap_context(ci->i_head_snapc);
+				ci->i_head_snapc = NULL;
+			}
 		} else {
 			BUG_ON(list_empty(&ci->i_dirty_item));
 		}
diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c
index 360c4f22718d..6fd8b20a8611 100644
--- a/fs/ceph/debugfs.c
+++ b/fs/ceph/debugfs.c
@@ -171,6 +171,8 @@ static int mdsc_show(struct seq_file *s, void *p)
 		} else if (req->r_dentry) {
 			path = ceph_mdsc_build_path(req->r_dentry, &pathlen,
 						    &pathbase, 0);
+			if (IS_ERR(path))
+				path = NULL;
 			spin_lock(&req->r_dentry->d_lock);
 			seq_printf(s, " #%llx/%.*s (%s)",
 				   ceph_ino(req->r_dentry->d_parent->d_inode),
@@ -187,6 +189,8 @@ static int mdsc_show(struct seq_file *s, void *p)
 		if (req->r_old_dentry) {
 			path = ceph_mdsc_build_path(req->r_old_dentry, &pathlen,
 						    &pathbase, 0);
+			if (IS_ERR(path))
+				path = NULL;
 			spin_lock(&req->r_old_dentry->d_lock);
 			seq_printf(s, " #%llx/%.*s (%s)",
 			   ceph_ino(req->r_old_dentry->d_parent->d_inode),
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 67bbb41d5526..6e4f43ff23ec 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -46,7 +46,7 @@ int ceph_init_dentry(struct dentry *dentry)
 	else
 		dentry->d_op = &ceph_snap_dentry_ops;
 
-	di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS);
+	di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS | __GFP_ZERO);
 	if (!di)
 		return -ENOMEM;          /* oh well */
 
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 5d893d31e399..e7cca414da03 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -677,6 +677,7 @@ static int fill_inode(struct inode *inode,
 		if (ci->i_files == 0 && ci->i_subdirs == 0 &&
 		    ceph_snap(inode) == CEPH_NOSNAP &&
 		    (le32_to_cpu(info->cap.caps) & CEPH_CAP_FILE_SHARED) &&
+		    (issued & CEPH_CAP_FILE_EXCL) == 0 &&
 		    (ci->i_ceph_flags & CEPH_I_COMPLETE) == 0) {
 			dout(" marking %p complete (empty)\n", inode);
 			ci->i_ceph_flags |= CEPH_I_COMPLETE;
@@ -1229,11 +1230,11 @@ retry_lookup:
 			in = dn->d_inode;
 		} else {
 			in = ceph_get_inode(parent->d_sb, vino);
-			if (in == NULL) {
+			if (IS_ERR(in)) {
 				dout("new_inode badness\n");
 				d_delete(dn);
 				dput(dn);
-				err = -ENOMEM;
+				err = PTR_ERR(in);
 				goto out;
 			}
 			dn = splice_dentry(dn, in, NULL);
diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c
index ae85af06454f..ff4e753aae92 100644
--- a/fs/ceph/locks.c
+++ b/fs/ceph/locks.c
@@ -82,7 +82,8 @@ int ceph_lock(struct file *file, int cmd, struct file_lock *fl)
 		length = fl->fl_end - fl->fl_start + 1;
 
 	err = ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
-				(u64)fl->fl_pid, (u64)fl->fl_nspid,
+				(u64)fl->fl_pid,
+				(u64)(unsigned long)fl->fl_nspid,
 				lock_cmd, fl->fl_start,
 				length, wait);
 	if (!err) {
@@ -92,7 +93,8 @@ int ceph_lock(struct file *file, int cmd, struct file_lock *fl)
 			/* undo! This should only happen if the kernel detects
 			 * local deadlock. */
 			ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
-					  (u64)fl->fl_pid, (u64)fl->fl_nspid,
+					  (u64)fl->fl_pid,
+					  (u64)(unsigned long)fl->fl_nspid,
 					  CEPH_LOCK_UNLOCK, fl->fl_start,
 					  length, 0);
 			dout("got %d on posix_lock_file, undid lock", err);
@@ -132,7 +134,8 @@ int ceph_flock(struct file *file, int cmd, struct file_lock *fl)
 		length = fl->fl_end - fl->fl_start + 1;
 
 	err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK,
-				file, (u64)fl->fl_pid, (u64)fl->fl_nspid,
+				file, (u64)fl->fl_pid,
+				(u64)(unsigned long)fl->fl_nspid,
 				lock_cmd, fl->fl_start,
 				length, wait);
 	if (!err) {
@@ -141,7 +144,7 @@ int ceph_flock(struct file *file, int cmd, struct file_lock *fl)
 			ceph_lock_message(CEPH_LOCK_FLOCK,
 					  CEPH_MDS_OP_SETFILELOCK,
 					  file, (u64)fl->fl_pid,
-					  (u64)fl->fl_nspid,
+					  (u64)(unsigned long)fl->fl_nspid,
 					  CEPH_LOCK_UNLOCK, fl->fl_start,
 					  length, 0);
 			dout("got %d on flock_lock_file_wait, undid lock", err);
@@ -235,7 +238,8 @@ int lock_to_ceph_filelock(struct file_lock *lock,
 	cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1);
 	cephlock->client = cpu_to_le64(0);
 	cephlock->pid = cpu_to_le64(lock->fl_pid);
-	cephlock->pid_namespace = cpu_to_le64((u64)lock->fl_nspid);
+	cephlock->pid_namespace =
+	        cpu_to_le64((u64)(unsigned long)lock->fl_nspid);
 
 	switch (lock->fl_type) {
 	case F_RDLCK:
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index a75ddbf9fe37..f091b1351786 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -560,6 +560,13 @@ static void __unregister_request(struct ceph_mds_client *mdsc,
  *
  * Called under mdsc->mutex.
  */
+struct dentry *get_nonsnap_parent(struct dentry *dentry)
+{
+	while (!IS_ROOT(dentry) && ceph_snap(dentry->d_inode) != CEPH_NOSNAP)
+		dentry = dentry->d_parent;
+	return dentry;
+}
+
 static int __choose_mds(struct ceph_mds_client *mdsc,
 			struct ceph_mds_request *req)
 {
@@ -590,14 +597,29 @@ static int __choose_mds(struct ceph_mds_client *mdsc,
 	if (req->r_inode) {
 		inode = req->r_inode;
 	} else if (req->r_dentry) {
-		if (req->r_dentry->d_inode) {
+		struct inode *dir = req->r_dentry->d_parent->d_inode;
+
+		if (dir->i_sb != mdsc->client->sb) {
+			/* not this fs! */
+			inode = req->r_dentry->d_inode;
+		} else if (ceph_snap(dir) != CEPH_NOSNAP) {
+			/* direct snapped/virtual snapdir requests
+			 * based on parent dir inode */
+			struct dentry *dn =
+				get_nonsnap_parent(req->r_dentry->d_parent);
+			inode = dn->d_inode;
+			dout("__choose_mds using nonsnap parent %p\n", inode);
+		} else if (req->r_dentry->d_inode) {
+			/* dentry target */
 			inode = req->r_dentry->d_inode;
 		} else {
-			inode = req->r_dentry->d_parent->d_inode;
+			/* dir + name */
+			inode = dir;
 			hash = req->r_dentry->d_name.hash;
 			is_hash = true;
 		}
 	}
+
 	dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 	     (int)hash, mode);
 	if (!inode)
@@ -2208,7 +2230,7 @@ static void handle_session(struct ceph_mds_session *session,
 			pr_info("mds%d reconnect denied\n", session->s_mds);
 		remove_session_caps(session);
 		wake = 1; /* for good measure */
-		complete_all(&mdsc->session_close_waiters);
+		wake_up_all(&mdsc->session_close_wq);
 		kick_requests(mdsc, mds);
 		break;
 
@@ -2302,7 +2324,7 @@ static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
 		path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
 		if (IS_ERR(path)) {
 			err = PTR_ERR(path);
-			BUG_ON(err);
+			goto out_dput;
 		}
 	} else {
 		path = NULL;
@@ -2310,7 +2332,7 @@ static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
 	}
 	err = ceph_pagelist_encode_string(pagelist, path, pathlen);
 	if (err)
-		goto out;
+		goto out_free;
 
 	spin_lock(&inode->i_lock);
 	cap->seq = 0;        /* reset cap seq */
@@ -2354,8 +2376,9 @@ static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
 		unlock_kernel();
 	}
 
-out:
+out_free:
 	kfree(path);
+out_dput:
 	dput(dentry);
 	return err;
 }
@@ -2876,7 +2899,7 @@ int ceph_mdsc_init(struct ceph_mds_client *mdsc, struct ceph_client *client)
 		return -ENOMEM;
 
 	init_completion(&mdsc->safe_umount_waiters);
-	init_completion(&mdsc->session_close_waiters);
+	init_waitqueue_head(&mdsc->session_close_wq);
 	INIT_LIST_HEAD(&mdsc->waiting_for_map);
 	mdsc->sessions = NULL;
 	mdsc->max_sessions = 0;
@@ -3021,6 +3044,23 @@ void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
 	wait_event(mdsc->cap_flushing_wq, check_cap_flush(mdsc, want_flush));
 }
 
+/*
+ * true if all sessions are closed, or we force unmount
+ */
+bool done_closing_sessions(struct ceph_mds_client *mdsc)
+{
+	int i, n = 0;
+
+	if (mdsc->client->mount_state == CEPH_MOUNT_SHUTDOWN)
+		return true;
+
+	mutex_lock(&mdsc->mutex);
+	for (i = 0; i < mdsc->max_sessions; i++)
+		if (mdsc->sessions[i])
+			n++;
+	mutex_unlock(&mdsc->mutex);
+	return n == 0;
+}
 
 /*
  * called after sb is ro.
@@ -3029,45 +3069,32 @@ void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
 {
 	struct ceph_mds_session *session;
 	int i;
-	int n;
 	struct ceph_client *client = mdsc->client;
-	unsigned long started, timeout = client->mount_args->mount_timeout * HZ;
+	unsigned long timeout = client->mount_args->mount_timeout * HZ;
 
 	dout("close_sessions\n");
 
-	mutex_lock(&mdsc->mutex);
-
 	/* close sessions */
-	started = jiffies;
-	while (time_before(jiffies, started + timeout)) {
-		dout("closing sessions\n");
-		n = 0;
-		for (i = 0; i < mdsc->max_sessions; i++) {
-			session = __ceph_lookup_mds_session(mdsc, i);
-			if (!session)
-				continue;
-			mutex_unlock(&mdsc->mutex);
-			mutex_lock(&session->s_mutex);
-			__close_session(mdsc, session);
-			mutex_unlock(&session->s_mutex);
-			ceph_put_mds_session(session);
-			mutex_lock(&mdsc->mutex);
-			n++;
-		}
-		if (n == 0)
-			break;
-
-		if (client->mount_state == CEPH_MOUNT_SHUTDOWN)
-			break;
-
-		dout("waiting for sessions to close\n");
+	mutex_lock(&mdsc->mutex);
+	for (i = 0; i < mdsc->max_sessions; i++) {
+		session = __ceph_lookup_mds_session(mdsc, i);
+		if (!session)
+			continue;
 		mutex_unlock(&mdsc->mutex);
-		wait_for_completion_timeout(&mdsc->session_close_waiters,
-					    timeout);
+		mutex_lock(&session->s_mutex);
+		__close_session(mdsc, session);
+		mutex_unlock(&session->s_mutex);
+		ceph_put_mds_session(session);
 		mutex_lock(&mdsc->mutex);
 	}
+	mutex_unlock(&mdsc->mutex);
+
+	dout("waiting for sessions to close\n");
+	wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
+			   timeout);
 
 	/* tear down remaining sessions */
+	mutex_lock(&mdsc->mutex);
 	for (i = 0; i < mdsc->max_sessions; i++) {
 		if (mdsc->sessions[i]) {
 			session = get_session(mdsc->sessions[i]);
@@ -3080,9 +3107,7 @@ void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
 			mutex_lock(&mdsc->mutex);
 		}
 	}
-
 	WARN_ON(!list_empty(&mdsc->cap_delay_list));
-
 	mutex_unlock(&mdsc->mutex);
 
 	ceph_cleanup_empty_realms(mdsc);
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index ab7e89f5e344..c98267ce6d2a 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -234,7 +234,8 @@ struct ceph_mds_client {
 	struct mutex            mutex;         /* all nested structures */
 
 	struct ceph_mdsmap      *mdsmap;
-	struct completion       safe_umount_waiters, session_close_waiters;
+	struct completion       safe_umount_waiters;
+	wait_queue_head_t       session_close_wq;
 	struct list_head        waiting_for_map;
 
 	struct ceph_mds_session **sessions;    /* NULL for mds if no session */
diff --git a/fs/ceph/osd_client.c b/fs/ceph/osd_client.c
index bed6391e52c7..dfced1dacbcd 100644
--- a/fs/ceph/osd_client.c
+++ b/fs/ceph/osd_client.c
@@ -661,7 +661,7 @@ static int __send_request(struct ceph_osd_client *osdc,
 	reqhead->reassert_version = req->r_reassert_version;
 
 	req->r_stamp = jiffies;
-	list_move_tail(&osdc->req_lru, &req->r_req_lru_item);
+	list_move_tail(&req->r_req_lru_item, &osdc->req_lru);
 
 	ceph_msg_get(req->r_request); /* send consumes a ref */
 	ceph_con_send(&req->r_osd->o_con, req->r_request);
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index c0b26b6badba..4868b9dcac5a 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -435,7 +435,7 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci)
 {
 	struct inode *inode = &ci->vfs_inode;
 	struct ceph_cap_snap *capsnap;
-	int used;
+	int used, dirty;
 
 	capsnap = kzalloc(sizeof(*capsnap), GFP_NOFS);
 	if (!capsnap) {
@@ -445,6 +445,7 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci)
 
 	spin_lock(&inode->i_lock);
 	used = __ceph_caps_used(ci);
+	dirty = __ceph_caps_dirty(ci);
 	if (__ceph_have_pending_cap_snap(ci)) {
 		/* there is no point in queuing multiple "pending" cap_snaps,
 		   as no new writes are allowed to start when pending, so any
@@ -452,11 +453,15 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci)
 		   cap_snap.  lucky us. */
 		dout("queue_cap_snap %p already pending\n", inode);
 		kfree(capsnap);
-	} else if (ci->i_wrbuffer_ref_head || (used & CEPH_CAP_FILE_WR)) {
+	} else if (ci->i_wrbuffer_ref_head || (used & CEPH_CAP_FILE_WR) ||
+		   (dirty & (CEPH_CAP_AUTH_EXCL|CEPH_CAP_XATTR_EXCL|
+			     CEPH_CAP_FILE_EXCL|CEPH_CAP_FILE_WR))) {
 		struct ceph_snap_context *snapc = ci->i_head_snapc;
 
+		dout("queue_cap_snap %p cap_snap %p queuing under %p\n", inode,
+		     capsnap, snapc);
 		igrab(inode);
-
+		
 		atomic_set(&capsnap->nref, 1);
 		capsnap->ci = ci;
 		INIT_LIST_HEAD(&capsnap->ci_item);
@@ -464,15 +469,21 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci)
 
 		capsnap->follows = snapc->seq - 1;
 		capsnap->issued = __ceph_caps_issued(ci, NULL);
-		capsnap->dirty = __ceph_caps_dirty(ci);
+		capsnap->dirty = dirty;
 
 		capsnap->mode = inode->i_mode;
 		capsnap->uid = inode->i_uid;
 		capsnap->gid = inode->i_gid;
 
-		/* fixme? */
-		capsnap->xattr_blob = NULL;
-		capsnap->xattr_len = 0;
+		if (dirty & CEPH_CAP_XATTR_EXCL) {
+			__ceph_build_xattrs_blob(ci);
+			capsnap->xattr_blob =
+				ceph_buffer_get(ci->i_xattrs.blob);
+			capsnap->xattr_version = ci->i_xattrs.version;
+		} else {
+			capsnap->xattr_blob = NULL;
+			capsnap->xattr_version = 0;
+		}
 
 		/* dirty page count moved from _head to this cap_snap;
 		   all subsequent writes page dirties occur _after_ this
@@ -480,7 +491,9 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci)
 		capsnap->dirty_pages = ci->i_wrbuffer_ref_head;
 		ci->i_wrbuffer_ref_head = 0;
 		capsnap->context = snapc;
-		ci->i_head_snapc = NULL;
+		ci->i_head_snapc =
+			ceph_get_snap_context(ci->i_snap_realm->cached_context);
+		dout(" new snapc is %p\n", ci->i_head_snapc);
 		list_add_tail(&capsnap->ci_item, &ci->i_cap_snaps);
 
 		if (used & CEPH_CAP_FILE_WR) {
@@ -539,6 +552,41 @@ int __ceph_finish_cap_snap(struct ceph_inode_info *ci,
 	return 1;  /* caller may want to ceph_flush_snaps */
 }
 
+/*
+ * Queue cap_snaps for snap writeback for this realm and its children.
+ * Called under snap_rwsem, so realm topology won't change.
+ */
+static void queue_realm_cap_snaps(struct ceph_snap_realm *realm)
+{
+	struct ceph_inode_info *ci;
+	struct inode *lastinode = NULL;
+	struct ceph_snap_realm *child;
+
+	dout("queue_realm_cap_snaps %p %llx inodes\n", realm, realm->ino);
+
+	spin_lock(&realm->inodes_with_caps_lock);
+	list_for_each_entry(ci, &realm->inodes_with_caps,
+			    i_snap_realm_item) {
+		struct inode *inode = igrab(&ci->vfs_inode);
+		if (!inode)
+			continue;
+		spin_unlock(&realm->inodes_with_caps_lock);
+		if (lastinode)
+			iput(lastinode);
+		lastinode = inode;
+		ceph_queue_cap_snap(ci);
+		spin_lock(&realm->inodes_with_caps_lock);
+	}
+	spin_unlock(&realm->inodes_with_caps_lock);
+	if (lastinode)
+		iput(lastinode);
+
+	dout("queue_realm_cap_snaps %p %llx children\n", realm, realm->ino);
+	list_for_each_entry(child, &realm->children, child_item)
+		queue_realm_cap_snaps(child);
+
+	dout("queue_realm_cap_snaps %p %llx done\n", realm, realm->ino);
+}
 
 /*
  * Parse and apply a snapblob "snap trace" from the MDS.  This specifies
@@ -589,29 +637,8 @@ more:
 		 *
 		 * ...unless it's a snap deletion!
 		 */
-		if (!deletion) {
-			struct ceph_inode_info *ci;
-			struct inode *lastinode = NULL;
-
-			spin_lock(&realm->inodes_with_caps_lock);
-			list_for_each_entry(ci, &realm->inodes_with_caps,
-					    i_snap_realm_item) {
-				struct inode *inode = igrab(&ci->vfs_inode);
-				if (!inode)
-					continue;
-				spin_unlock(&realm->inodes_with_caps_lock);
-				if (lastinode)
-					iput(lastinode);
-				lastinode = inode;
-				ceph_queue_cap_snap(ci);
-				spin_lock(&realm->inodes_with_caps_lock);
-			}
-			spin_unlock(&realm->inodes_with_caps_lock);
-			if (lastinode)
-				iput(lastinode);
-			dout("update_snap_trace cap_snaps queued\n");
-		}
-
+		if (!deletion)
+			queue_realm_cap_snaps(realm);
 	} else {
 		dout("update_snap_trace %llx %p seq %lld unchanged\n",
 		     realm->ino, realm, realm->seq);
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 2482d696f0de..c33897ae5725 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -216,8 +216,7 @@ struct ceph_cap_snap {
 	uid_t uid;
 	gid_t gid;
 
-	void *xattr_blob;
-	int xattr_len;
+	struct ceph_buffer *xattr_blob;
 	u64 xattr_version;
 
 	u64 size;
@@ -229,8 +228,11 @@ struct ceph_cap_snap {
 
 static inline void ceph_put_cap_snap(struct ceph_cap_snap *capsnap)
 {
-	if (atomic_dec_and_test(&capsnap->nref))
+	if (atomic_dec_and_test(&capsnap->nref)) {
+		if (capsnap->xattr_blob)
+			ceph_buffer_put(capsnap->xattr_blob);
 		kfree(capsnap);
+	}
 }
 
 /*
@@ -342,7 +344,8 @@ struct ceph_inode_info {
 	unsigned i_cap_exporting_issued;
 	struct ceph_cap_reservation i_cap_migration_resv;
 	struct list_head i_cap_snaps;   /* snapped state pending flush to mds */
-	struct ceph_snap_context *i_head_snapc;  /* set if wr_buffer_head > 0 */
+	struct ceph_snap_context *i_head_snapc;  /* set if wr_buffer_head > 0 or
+						    dirty|flushing caps */
 	unsigned i_snap_caps;           /* cap bits for snapped files */
 
 	int i_nr_by_mode[CEPH_FILE_MODE_NUM];  /* open file counts */
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 097a2654c00f..9578af610b73 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -485,6 +485,7 @@ void __ceph_build_xattrs_blob(struct ceph_inode_info *ci)
 		ci->i_xattrs.blob = ci->i_xattrs.prealloc_blob;
 		ci->i_xattrs.prealloc_blob = NULL;
 		ci->i_xattrs.dirty = false;
+		ci->i_xattrs.version++;
 	}
 }
 
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index a803f5e33471..e3bccac1f025 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1126,6 +1126,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
 		task_io_account_write(PAGE_CACHE_SIZE);
 	}
 }
+EXPORT_SYMBOL(account_page_dirtied);
 
 /*
  * For address_spaces which do not use buffers.  Just tag the page as dirty in