1 files changed, 117 insertions, 63 deletions

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 9b85b5341822..7a16e12f5da8 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -175,6 +175,8 @@ cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+		if (cifs_ses_exiting(ses))
+			continue;
 		spin_lock(&ses->chan_lock);
 		for (i = 0; i < ses->chan_count; i++) {
 			if (!ses->chans[i].server)
@@ -232,7 +234,13 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
-		/* check if iface is still active */
+		spin_lock(&ses->ses_lock);
+		if (ses->ses_status == SES_EXITING) {
+			spin_unlock(&ses->ses_lock);
+			continue;
+		}
+		spin_unlock(&ses->ses_lock);
+
 		spin_lock(&ses->chan_lock);
 		if (cifs_ses_get_chan_index(ses, server) ==
 		    CIFS_INVAL_CHAN_INDEX) {
@@ -1860,6 +1868,9 @@ static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 	    ctx->sectype != ses->sectype)
 		return 0;
 
+	if (ctx->dfs_root_ses != ses->dfs_root_ses)
+		return 0;
+
 	/*
 	 * If an existing session is limited to less channels than
 	 * requested, it should not be reused
@@ -1932,7 +1943,7 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 	}
 
 	/* no need to setup directory caching on IPC share, so pass in false */
-	tcon = tcon_info_alloc(false);
+	tcon = tcon_info_alloc(false, netfs_trace_tcon_ref_new_ipc);
 	if (tcon == NULL)
 		return -ENOMEM;
 
@@ -1949,7 +1960,7 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 
 	if (rc) {
 		cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
-		tconInfoFree(tcon);
+		tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc_fail);
 		goto out;
 	}
 
@@ -1963,31 +1974,6 @@ out:
 	return rc;
 }
 
-/**
- * cifs_free_ipc - helper to release the session IPC tcon
- * @ses: smb session to unmount the IPC from
- *
- * Needs to be called everytime a session is destroyed.
- *
- * On session close, the IPC is closed and the server must release all tcons of the session.
- * No need to send a tree disconnect here.
- *
- * Besides, it will make the server to not close durable and resilient files on session close, as
- * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
- */
-static int
-cifs_free_ipc(struct cifs_ses *ses)
-{
-	struct cifs_tcon *tcon = ses->tcon_ipc;
-
-	if (tcon == NULL)
-		return 0;
-
-	tconInfoFree(tcon);
-	ses->tcon_ipc = NULL;
-	return 0;
-}
-
 static struct cifs_ses *
 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 {
@@ -2019,48 +2005,52 @@ cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 void __cifs_put_smb_ses(struct cifs_ses *ses)
 {
 	struct TCP_Server_Info *server = ses->server;
+	struct cifs_tcon *tcon;
 	unsigned int xid;
 	size_t i;
+	bool do_logoff;
 	int rc;
 
+	spin_lock(&cifs_tcp_ses_lock);
 	spin_lock(&ses->ses_lock);
-	if (ses->ses_status == SES_EXITING) {
+	cifs_dbg(FYI, "%s: id=0x%llx ses_count=%d ses_status=%u ipc=%s\n",
+		 __func__, ses->Suid, ses->ses_count, ses->ses_status,
+		 ses->tcon_ipc ? ses->tcon_ipc->tree_name : "none");
+	if (ses->ses_status == SES_EXITING || --ses->ses_count > 0) {
 		spin_unlock(&ses->ses_lock);
+		spin_unlock(&cifs_tcp_ses_lock);
 		return;
 	}
-	spin_unlock(&ses->ses_lock);
+	/* ses_count can never go negative */
+	WARN_ON(ses->ses_count < 0);
 
-	cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
-	cifs_dbg(FYI,
-		 "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
+	spin_lock(&ses->chan_lock);
+	cifs_chan_clear_need_reconnect(ses, server);
+	spin_unlock(&ses->chan_lock);
 
-	spin_lock(&cifs_tcp_ses_lock);
-	if (--ses->ses_count > 0) {
-		spin_unlock(&cifs_tcp_ses_lock);
-		return;
-	}
-	spin_lock(&ses->ses_lock);
-	if (ses->ses_status == SES_GOOD)
-		ses->ses_status = SES_EXITING;
+	do_logoff = ses->ses_status == SES_GOOD && server->ops->logoff;
+	ses->ses_status = SES_EXITING;
+	tcon = ses->tcon_ipc;
+	ses->tcon_ipc = NULL;
 	spin_unlock(&ses->ses_lock);
 	spin_unlock(&cifs_tcp_ses_lock);
 
-	/* ses_count can never go negative */
-	WARN_ON(ses->ses_count < 0);
-
-	spin_lock(&ses->ses_lock);
-	if (ses->ses_status == SES_EXITING && server->ops->logoff) {
-		spin_unlock(&ses->ses_lock);
-		cifs_free_ipc(ses);
+	/*
+	 * On session close, the IPC is closed and the server must release all
+	 * tcons of the session.  No need to send a tree disconnect here.
+	 *
+	 * Besides, it will make the server to not close durable and resilient
+	 * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an
+	 * SMB2 LOGOFF Request.
+	 */
+	tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc);
+	if (do_logoff) {
 		xid = get_xid();
 		rc = server->ops->logoff(xid, ses);
 		if (rc)
 			cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
 				__func__, rc);
 		_free_xid(xid);
-	} else {
-		spin_unlock(&ses->ses_lock);
-		cifs_free_ipc(ses);
 	}
 
 	spin_lock(&cifs_tcp_ses_lock);
@@ -2193,6 +2183,7 @@ cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
 	}
 
 	++delim;
+	/* BB consider adding support for password2 (Key Rotation) for multiuser in future */
 	ctx->password = kstrndup(delim, len, GFP_KERNEL);
 	if (!ctx->password) {
 		cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
@@ -2216,6 +2207,7 @@ cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
 			kfree(ctx->username);
 			ctx->username = NULL;
 			kfree_sensitive(ctx->password);
+			/* no need to free ctx->password2 since not allocated in this path */
 			ctx->password = NULL;
 			goto out_key_put;
 		}
@@ -2327,6 +2319,12 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 		if (!ses->password)
 			goto get_ses_fail;
 	}
+	/* ctx->password freed at unmount */
+	if (ctx->password2) {
+		ses->password2 = kstrdup(ctx->password2, GFP_KERNEL);
+		if (!ses->password2)
+			goto get_ses_fail;
+	}
 	if (ctx->domainname) {
 		ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
 		if (!ses->domainName)
@@ -2373,9 +2371,9 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 	 * need to lock before changing something in the session.
 	 */
 	spin_lock(&cifs_tcp_ses_lock);
+	if (ctx->dfs_root_ses)
+		cifs_smb_ses_inc_refcount(ctx->dfs_root_ses);
 	ses->dfs_root_ses = ctx->dfs_root_ses;
-	if (ses->dfs_root_ses)
-		ses->dfs_root_ses->ses_count++;
 	list_add(&ses->smb_ses_list, &server->smb_ses_list);
 	spin_unlock(&cifs_tcp_ses_lock);
 
@@ -2434,6 +2432,8 @@ cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 			continue;
 		}
 		++tcon->tc_count;
+		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+				    netfs_trace_tcon_ref_get_find);
 		spin_unlock(&tcon->tc_lock);
 		spin_unlock(&cifs_tcp_ses_lock);
 		return tcon;
@@ -2443,7 +2443,7 @@ cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 }
 
 void
-cifs_put_tcon(struct cifs_tcon *tcon)
+cifs_put_tcon(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
 {
 	unsigned int xid;
 	struct cifs_ses *ses;
@@ -2459,6 +2459,7 @@ cifs_put_tcon(struct cifs_tcon *tcon)
 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
 	spin_lock(&cifs_tcp_ses_lock);
 	spin_lock(&tcon->tc_lock);
+	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count - 1, trace);
 	if (--tcon->tc_count > 0) {
 		spin_unlock(&tcon->tc_lock);
 		spin_unlock(&cifs_tcp_ses_lock);
@@ -2495,7 +2496,7 @@ cifs_put_tcon(struct cifs_tcon *tcon)
 	_free_xid(xid);
 
 	cifs_fscache_release_super_cookie(tcon);
-	tconInfoFree(tcon);
+	tconInfoFree(tcon, netfs_trace_tcon_ref_free);
 	cifs_put_smb_ses(ses);
 }
 
@@ -2549,7 +2550,7 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 		nohandlecache = ctx->nohandlecache;
 	else
 		nohandlecache = true;
-	tcon = tcon_info_alloc(!nohandlecache);
+	tcon = tcon_info_alloc(!nohandlecache, netfs_trace_tcon_ref_new);
 	if (tcon == NULL) {
 		rc = -ENOMEM;
 		goto out_fail;
@@ -2739,7 +2740,7 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 	return tcon;
 
 out_fail:
-	tconInfoFree(tcon);
+	tconInfoFree(tcon, netfs_trace_tcon_ref_free_fail);
 	return ERR_PTR(rc);
 }
 
@@ -2756,7 +2757,7 @@ cifs_put_tlink(struct tcon_link *tlink)
 	}
 
 	if (!IS_ERR(tlink_tcon(tlink)))
-		cifs_put_tcon(tlink_tcon(tlink));
+		cifs_put_tcon(tlink_tcon(tlink), netfs_trace_tcon_ref_put_tlink);
 	kfree(tlink);
 }
 
@@ -3321,11 +3322,14 @@ void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
 	int rc = 0;
 
 	if (mnt_ctx->tcon)
-		cifs_put_tcon(mnt_ctx->tcon);
+		cifs_put_tcon(mnt_ctx->tcon, netfs_trace_tcon_ref_put_mnt_ctx);
 	else if (mnt_ctx->ses)
 		cifs_put_smb_ses(mnt_ctx->ses);
 	else if (mnt_ctx->server)
 		cifs_put_tcp_session(mnt_ctx->server, 0);
+	mnt_ctx->ses = NULL;
+	mnt_ctx->tcon = NULL;
+	mnt_ctx->server = NULL;
 	mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
 	free_xid(mnt_ctx->xid);
 }
@@ -3604,8 +3608,6 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
 	bool isdfs;
 	int rc;
 
-	INIT_LIST_HEAD(&mnt_ctx.dfs_ses_list);
-
 	rc = dfs_mount_share(&mnt_ctx, &isdfs);
 	if (rc)
 		goto error;
@@ -3636,7 +3638,6 @@ out:
 	return rc;
 
 error:
-	dfs_put_root_smb_sessions(&mnt_ctx.dfs_ses_list);
 	cifs_mount_put_conns(&mnt_ctx);
 	return rc;
 }
@@ -3651,6 +3652,18 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
 		goto error;
 
 	rc = cifs_mount_get_tcon(&mnt_ctx);
+	if (!rc) {
+		/*
+		 * Prevent superblock from being created with any missing
+		 * connections.
+		 */
+		if (WARN_ON(!mnt_ctx.server))
+			rc = -EHOSTDOWN;
+		else if (WARN_ON(!mnt_ctx.ses))
+			rc = -EACCES;
+		else if (WARN_ON(!mnt_ctx.tcon))
+			rc = -ENOENT;
+	}
 	if (rc)
 		goto error;
 
@@ -3988,13 +4001,14 @@ cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
 }
 
 static struct cifs_tcon *
-cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
+__cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
 {
 	int rc;
 	struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
 	struct cifs_ses *ses;
 	struct cifs_tcon *tcon = NULL;
 	struct smb3_fs_context *ctx;
+	char *origin_fullpath = NULL;
 
 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 	if (ctx == NULL)
@@ -4018,6 +4032,7 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
 	ctx->sign = master_tcon->ses->sign;
 	ctx->seal = master_tcon->seal;
 	ctx->witness = master_tcon->use_witness;
+	ctx->dfs_root_ses = master_tcon->ses->dfs_root_ses;
 
 	rc = cifs_set_vol_auth(ctx, master_tcon->ses);
 	if (rc) {
@@ -4037,12 +4052,39 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
 		goto out;
 	}
 
+#ifdef CONFIG_CIFS_DFS_UPCALL
+	spin_lock(&master_tcon->tc_lock);
+	if (master_tcon->origin_fullpath) {
+		spin_unlock(&master_tcon->tc_lock);
+		origin_fullpath = dfs_get_path(cifs_sb, cifs_sb->ctx->source);
+		if (IS_ERR(origin_fullpath)) {
+			tcon = ERR_CAST(origin_fullpath);
+			origin_fullpath = NULL;
+			cifs_put_smb_ses(ses);
+			goto out;
+		}
+	} else {
+		spin_unlock(&master_tcon->tc_lock);
+	}
+#endif
+
 	tcon = cifs_get_tcon(ses, ctx);
 	if (IS_ERR(tcon)) {
 		cifs_put_smb_ses(ses);
 		goto out;
 	}
 
+#ifdef CONFIG_CIFS_DFS_UPCALL
+	if (origin_fullpath) {
+		spin_lock(&tcon->tc_lock);
+		tcon->origin_fullpath = origin_fullpath;
+		spin_unlock(&tcon->tc_lock);
+		origin_fullpath = NULL;
+		queue_delayed_work(dfscache_wq, &tcon->dfs_cache_work,
+				   dfs_cache_get_ttl() * HZ);
+	}
+#endif
+
 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 	if (cap_unix(ses))
 		reset_cifs_unix_caps(0, tcon, NULL, ctx);
@@ -4051,11 +4093,23 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
 out:
 	kfree(ctx->username);
 	kfree_sensitive(ctx->password);
+	kfree(origin_fullpath);
 	kfree(ctx);
 
 	return tcon;
 }
 
+static struct cifs_tcon *
+cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
+{
+	struct cifs_tcon *ret;
+
+	cifs_mount_lock();
+	ret = __cifs_construct_tcon(cifs_sb, fsuid);
+	cifs_mount_unlock();
+	return ret;
+}
+
 struct cifs_tcon *
 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
 {