1 files changed, 107 insertions, 44 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index bd8c00635ea4..8924f1427472 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -360,8 +360,10 @@ static int reconn_set_ipaddr(struct TCP_Server_Info *server)
 		return rc;
 	}
 
+	spin_lock(&cifs_tcp_ses_lock);
 	rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
 				  strlen(ipaddr));
+	spin_unlock(&cifs_tcp_ses_lock);
 	kfree(ipaddr);
 
 	return !rc ? -1 : 0;
@@ -376,7 +378,7 @@ static inline int reconn_set_ipaddr(struct TCP_Server_Info *server)
 #ifdef CONFIG_CIFS_DFS_UPCALL
 struct super_cb_data {
 	struct TCP_Server_Info *server;
-	struct cifs_sb_info *cifs_sb;
+	struct super_block *sb;
 };
 
 /* These functions must be called with server->srv_mutex held */
@@ -387,25 +389,39 @@ static void super_cb(struct super_block *sb, void *arg)
 	struct cifs_sb_info *cifs_sb;
 	struct cifs_tcon *tcon;
 
-	if (d->cifs_sb)
+	if (d->sb)
 		return;
 
 	cifs_sb = CIFS_SB(sb);
 	tcon = cifs_sb_master_tcon(cifs_sb);
 	if (tcon->ses->server == d->server)
-		d->cifs_sb = cifs_sb;
+		d->sb = sb;
 }
 
-static inline struct cifs_sb_info *
-find_super_by_tcp(struct TCP_Server_Info *server)
+static struct super_block *get_tcp_super(struct TCP_Server_Info *server)
 {
 	struct super_cb_data d = {
 		.server = server,
-		.cifs_sb = NULL,
+		.sb = NULL,
 	};
 
 	iterate_supers_type(&cifs_fs_type, super_cb, &d);
-	return d.cifs_sb ? d.cifs_sb : ERR_PTR(-ENOENT);
+
+	if (unlikely(!d.sb))
+		return ERR_PTR(-ENOENT);
+	/*
+	 * Grab an active reference in order to prevent automounts (DFS links)
+	 * of expiring and then freeing up our cifs superblock pointer while
+	 * we're doing failover.
+	 */
+	cifs_sb_active(d.sb);
+	return d.sb;
+}
+
+static inline void put_tcp_super(struct super_block *sb)
+{
+	if (!IS_ERR_OR_NULL(sb))
+		cifs_sb_deactive(sb);
 }
 
 static void reconn_inval_dfs_target(struct TCP_Server_Info *server,
@@ -469,6 +485,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
 	struct mid_q_entry *mid_entry;
 	struct list_head retry_list;
 #ifdef CONFIG_CIFS_DFS_UPCALL
+	struct super_block *sb = NULL;
 	struct cifs_sb_info *cifs_sb = NULL;
 	struct dfs_cache_tgt_list tgt_list = {0};
 	struct dfs_cache_tgt_iterator *tgt_it = NULL;
@@ -478,13 +495,15 @@ cifs_reconnect(struct TCP_Server_Info *server)
 	server->nr_targets = 1;
 #ifdef CONFIG_CIFS_DFS_UPCALL
 	spin_unlock(&GlobalMid_Lock);
-	cifs_sb = find_super_by_tcp(server);
-	if (IS_ERR(cifs_sb)) {
-		rc = PTR_ERR(cifs_sb);
+	sb = get_tcp_super(server);
+	if (IS_ERR(sb)) {
+		rc = PTR_ERR(sb);
 		cifs_dbg(FYI, "%s: will not do DFS failover: rc = %d\n",
 			 __func__, rc);
-		cifs_sb = NULL;
+		sb = NULL;
 	} else {
+		cifs_sb = CIFS_SB(sb);
+
 		rc = reconn_setup_dfs_targets(cifs_sb, &tgt_list, &tgt_it);
 		if (rc && (rc != -EOPNOTSUPP)) {
 			cifs_dbg(VFS, "%s: no target servers for DFS failover\n",
@@ -501,6 +520,10 @@ cifs_reconnect(struct TCP_Server_Info *server)
 		/* the demux thread will exit normally
 		next time through the loop */
 		spin_unlock(&GlobalMid_Lock);
+#ifdef CONFIG_CIFS_DFS_UPCALL
+		dfs_cache_free_tgts(&tgt_list);
+		put_tcp_super(sb);
+#endif
 		return rc;
 	} else
 		server->tcpStatus = CifsNeedReconnect;
@@ -553,9 +576,11 @@ cifs_reconnect(struct TCP_Server_Info *server)
 	spin_lock(&GlobalMid_Lock);
 	list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 		mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
+		kref_get(&mid_entry->refcount);
 		if (mid_entry->mid_state == MID_REQUEST_SUBMITTED)
 			mid_entry->mid_state = MID_RETRY_NEEDED;
 		list_move(&mid_entry->qhead, &retry_list);
+		mid_entry->mid_flags |= MID_DELETED;
 	}
 	spin_unlock(&GlobalMid_Lock);
 	mutex_unlock(&server->srv_mutex);
@@ -565,6 +590,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
 		mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 		list_del_init(&mid_entry->qhead);
 		mid_entry->callback(mid_entry);
+		cifs_mid_q_entry_release(mid_entry);
 	}
 
 	if (cifs_rdma_enabled(server)) {
@@ -577,26 +603,26 @@ cifs_reconnect(struct TCP_Server_Info *server)
 		try_to_freeze();
 
 		mutex_lock(&server->srv_mutex);
+#ifdef CONFIG_CIFS_DFS_UPCALL
 		/*
 		 * Set up next DFS target server (if any) for reconnect. If DFS
 		 * feature is disabled, then we will retry last server we
 		 * connected to before.
 		 */
+		reconn_inval_dfs_target(server, cifs_sb, &tgt_list, &tgt_it);
+#endif
+		rc = reconn_set_ipaddr(server);
+		if (rc) {
+			cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
+				 __func__, rc);
+		}
+
 		if (cifs_rdma_enabled(server))
 			rc = smbd_reconnect(server);
 		else
 			rc = generic_ip_connect(server);
 		if (rc) {
 			cifs_dbg(FYI, "reconnect error %d\n", rc);
-#ifdef CONFIG_CIFS_DFS_UPCALL
-			reconn_inval_dfs_target(server, cifs_sb, &tgt_list,
-						&tgt_it);
-#endif
-			rc = reconn_set_ipaddr(server);
-			if (rc) {
-				cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
-					 __func__, rc);
-			}
 			mutex_unlock(&server->srv_mutex);
 			msleep(3000);
 		} else {
@@ -624,7 +650,10 @@ cifs_reconnect(struct TCP_Server_Info *server)
 				 __func__, rc);
 		}
 		dfs_cache_free_tgts(&tgt_list);
+
 	}
+
+	put_tcp_super(sb);
 #endif
 	if (server->tcpStatus == CifsNeedNegotiate)
 		mod_delayed_work(cifsiod_wq, &server->echo, 0);
@@ -884,11 +913,27 @@ dequeue_mid(struct mid_q_entry *mid, bool malformed)
 	if (mid->mid_flags & MID_DELETED)
 		printk_once(KERN_WARNING
 			    "trying to dequeue a deleted mid\n");
-	else
+	else {
 		list_del_init(&mid->qhead);
+		mid->mid_flags |= MID_DELETED;
+	}
 	spin_unlock(&GlobalMid_Lock);
 }
 
+static unsigned int
+smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
+{
+	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
+
+	/*
+	 * SMB1 does not use credits.
+	 */
+	if (server->vals->header_preamble_size)
+		return 0;
+
+	return le16_to_cpu(shdr->CreditRequest);
+}
+
 static void
 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 	   char *buf, int malformed)
@@ -896,6 +941,7 @@ handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 	if (server->ops->check_trans2 &&
 	    server->ops->check_trans2(mid, server, buf, malformed))
 		return;
+	mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 	mid->resp_buf = buf;
 	mid->large_buf = server->large_buf;
 	/* Was previous buf put in mpx struct for multi-rsp? */
@@ -955,8 +1001,10 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server)
 		list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 			cifs_dbg(FYI, "Clearing mid 0x%llx\n", mid_entry->mid);
+			kref_get(&mid_entry->refcount);
 			mid_entry->mid_state = MID_SHUTDOWN;
 			list_move(&mid_entry->qhead, &dispose_list);
+			mid_entry->mid_flags |= MID_DELETED;
 		}
 		spin_unlock(&GlobalMid_Lock);
 
@@ -966,6 +1014,7 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server)
 			cifs_dbg(FYI, "Callback mid 0x%llx\n", mid_entry->mid);
 			list_del_init(&mid_entry->qhead);
 			mid_entry->callback(mid_entry);
+			cifs_mid_q_entry_release(mid_entry);
 		}
 		/* 1/8th of sec is more than enough time for them to exit */
 		msleep(125);
@@ -1202,12 +1251,6 @@ next_pdu:
 		for (i = 0; i < num_mids; i++) {
 			if (mids[i] != NULL) {
 				mids[i]->resp_buf_size = server->pdu_size;
-				if ((mids[i]->mid_flags & MID_WAIT_CANCELLED) &&
-				    mids[i]->mid_state == MID_RESPONSE_RECEIVED &&
-				    server->ops->handle_cancelled_mid)
-					server->ops->handle_cancelled_mid(
-							mids[i]->resp_buf,
-							server);
 
 				if (!mids[i]->multiRsp || mids[i]->multiEnd)
 					mids[i]->callback(mids[i]);
@@ -3248,6 +3291,10 @@ cifs_find_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each(tmp, &ses->tcon_list) {
 		tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
+#ifdef CONFIG_CIFS_DFS_UPCALL
+		if (tcon->dfs_path)
+			continue;
+#endif
 		if (!match_tcon(tcon, volume_info))
 			continue;
 		++tcon->tc_count;
@@ -3532,8 +3579,10 @@ match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
 {
 	struct cifs_sb_info *old = CIFS_SB(sb);
 	struct cifs_sb_info *new = mnt_data->cifs_sb;
-	bool old_set = old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH;
-	bool new_set = new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH;
+	bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
+		old->prepath;
+	bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
+		new->prepath;
 
 	if (old_set && new_set && !strcmp(new->prepath, old->prepath))
 		return 1;
@@ -3964,7 +4013,7 @@ int cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
 	cifs_sb->mnt_gid = pvolume_info->linux_gid;
 	cifs_sb->mnt_file_mode = pvolume_info->file_mode;
 	cifs_sb->mnt_dir_mode = pvolume_info->dir_mode;
-	cifs_dbg(FYI, "file mode: 0x%hx  dir mode: 0x%hx\n",
+	cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
 		 cifs_sb->mnt_file_mode, cifs_sb->mnt_dir_mode);
 
 	cifs_sb->actimeo = pvolume_info->actimeo;
@@ -4582,6 +4631,17 @@ static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb_vol *vol,
 }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
+static inline void set_root_tcon(struct cifs_sb_info *cifs_sb,
+				 struct cifs_tcon *tcon,
+				 struct cifs_tcon **root)
+{
+	spin_lock(&cifs_tcp_ses_lock);
+	tcon->tc_count++;
+	tcon->remap = cifs_remap(cifs_sb);
+	spin_unlock(&cifs_tcp_ses_lock);
+	*root = tcon;
+}
+
 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol)
 {
 	int rc = 0;
@@ -4683,18 +4743,10 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol)
 	/* Cache out resolved root server */
 	(void)dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
 			     root_path + 1, NULL, NULL);
-	/*
-	 * Save root tcon for additional DFS requests to update or create a new
-	 * DFS cache entry, or even perform DFS failover.
-	 */
-	spin_lock(&cifs_tcp_ses_lock);
-	tcon->tc_count++;
-	tcon->dfs_path = root_path;
+	kfree(root_path);
 	root_path = NULL;
-	tcon->remap = cifs_remap(cifs_sb);
-	spin_unlock(&cifs_tcp_ses_lock);
 
-	root_tcon = tcon;
+	set_root_tcon(cifs_sb, tcon, &root_tcon);
 
 	for (count = 1; ;) {
 		if (!rc && tcon) {
@@ -4731,6 +4783,15 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol)
 			mount_put_conns(cifs_sb, xid, server, ses, tcon);
 			rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses,
 					     &tcon);
+			/*
+			 * Ensure that DFS referrals go through new root server.
+			 */
+			if (!rc && tcon &&
+			    (tcon->share_flags & (SHI1005_FLAGS_DFS |
+						  SHI1005_FLAGS_DFS_ROOT))) {
+				cifs_put_tcon(root_tcon);
+				set_root_tcon(cifs_sb, tcon, &root_tcon);
+			}
 		}
 		if (rc) {
 			if (rc == -EACCES || rc == -EOPNOTSUPP)
@@ -5110,9 +5171,15 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
 	vol_info->nocase = master_tcon->nocase;
 	vol_info->nohandlecache = master_tcon->nohandlecache;
 	vol_info->local_lease = master_tcon->local_lease;
+	vol_info->no_lease = master_tcon->no_lease;
+	vol_info->resilient = master_tcon->use_resilient;
+	vol_info->persistent = master_tcon->use_persistent;
+	vol_info->handle_timeout = master_tcon->handle_timeout;
 	vol_info->no_linux_ext = !master_tcon->unix_ext;
+	vol_info->linux_ext = master_tcon->posix_extensions;
 	vol_info->sectype = master_tcon->ses->sectype;
 	vol_info->sign = master_tcon->ses->sign;
+	vol_info->seal = master_tcon->seal;
 
 	rc = cifs_set_vol_auth(vol_info, master_tcon->ses);
 	if (rc) {
@@ -5138,10 +5205,6 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
 		goto out;
 	}
 
-	/* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
-	if (tcon->posix_extensions)
-		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
-
 	if (cap_unix(ses))
 		reset_cifs_unix_caps(0, tcon, NULL, vol_info);