6 cifs/smb3 client fixes

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Merge tag '6.2-rc2-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "cifs/smb3 client fixes:

   - two multichannel fixes

   - three reconnect fixes

   - unmap fix"

* tag '6.2-rc2-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix interface count calculation during refresh
  cifs: refcount only the selected iface during interface update
  cifs: protect access of TCP_Server_Info::{dstaddr,hostname}
  cifs: fix race in assemble_neg_contexts()
  cifs: ignore ipc reconnect failures during dfs failover
  cifs: Fix kmap_local_page() unmapping

fs/cifs/dfs.c

@@ -327,8 +327,8 @@ static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb
 	return rc;
 }
 
-static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
-				       size_t tcp_host_len, char *share, bool *target_match)
+static int target_share_matches_server(struct TCP_Server_Info *server, char *share,
+				       bool *target_match)
 {
 	int rc = 0;
 	const char *dfs_host;
@@ -338,13 +338,16 @@ static int target_share_matches_server(struct TCP_Server_Info *server, const cha
 	extract_unc_hostname(share, &dfs_host, &dfs_host_len);
 
 	/* Check if hostnames or addresses match */
-	if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
-		cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
-			 dfs_host, (int)tcp_host_len, tcp_host);
+	cifs_server_lock(server);
+	if (dfs_host_len != strlen(server->hostname) ||
+	    strncasecmp(dfs_host, server->hostname, dfs_host_len)) {
+		cifs_dbg(FYI, "%s: %.*s doesn't match %s\n", __func__,
+			 (int)dfs_host_len, dfs_host, server->hostname);
 		rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
 		if (rc)
 			cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
 	}
+	cifs_server_unlock(server);
 	return rc;
 }
 
@@ -358,13 +361,9 @@ static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *t
 	struct cifs_ses *root_ses = CIFS_DFS_ROOT_SES(tcon->ses);
 	struct cifs_tcon *ipc = root_ses->tcon_ipc;
 	char *share = NULL, *prefix = NULL;
-	const char *tcp_host;
-	size_t tcp_host_len;
 	struct dfs_cache_tgt_iterator *tit;
 	bool target_match;
 
-	extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
-
 	tit = dfs_cache_get_tgt_iterator(tl);
 	if (!tit) {
 		rc = -ENOENT;
@@ -387,8 +386,7 @@ static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *t
 			break;
 		}
 
-		rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
-						 &target_match);
+		rc = target_share_matches_server(server, share, &target_match);
 		if (rc)
 			break;
 		if (!target_match) {
@@ -401,8 +399,7 @@ static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *t
 		if (ipc->need_reconnect) {
 			scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
 			rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
-			if (rc)
-				break;
+			cifs_dbg(FYI, "%s: reconnect ipc: %d\n", __func__, rc);
 		}
 
 		scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
@@ -498,7 +495,9 @@ int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const stru
 	}
 
 	if (tcon->ipc) {
+		cifs_server_lock(server);
 		scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
+		cifs_server_unlock(server);
 		rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
 		goto out;
 	}

fs/cifs/misc.c

@@ -1277,7 +1277,9 @@ int match_target_ip(struct TCP_Server_Info *server,
 	if (rc < 0)
 		return rc;
 
+	spin_lock(&server->srv_lock);
 	*result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);
+	spin_unlock(&server->srv_lock);
 	cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
 	return 0;
 }

fs/cifs/sess.c

@@ -292,9 +292,10 @@ cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server)
 			continue;
 		}
 		kref_get(&iface->refcount);
+		break;
 	}
 
-	if (!list_entry_is_head(iface, &ses->iface_list, iface_head)) {
+	if (list_entry_is_head(iface, &ses->iface_list, iface_head)) {
 		rc = 1;
 		iface = NULL;
 		cifs_dbg(FYI, "unable to find a suitable iface\n");

fs/cifs/smb2ops.c

@@ -530,7 +530,6 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 	p = buf;
 
 	spin_lock(&ses->iface_lock);
-	ses->iface_count = 0;
 	/*
 	 * Go through iface_list and do kref_put to remove
 	 * any unused ifaces. ifaces in use will be removed
@@ -540,6 +539,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 				 iface_head) {
 		iface->is_active = 0;
 		kref_put(&iface->refcount, release_iface);
+		ses->iface_count--;
 	}
 	spin_unlock(&ses->iface_lock);
 
@@ -618,6 +618,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 				/* just get a ref so that it doesn't get picked/freed */
 				iface->is_active = 1;
 				kref_get(&iface->refcount);
+				ses->iface_count++;
 				spin_unlock(&ses->iface_lock);
 				goto next_iface;
 			} else if (ret < 0) {
@@ -4488,17 +4489,12 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, int num_rqst,
 
 		/* copy pages form the old */
 		for (j = 0; j < npages; j++) {
-			char *dst, *src;
 			unsigned int offset, len;
 
 			rqst_page_get_length(new, j, &len, &offset);
 
-			dst = kmap_local_page(new->rq_pages[j]) + offset;
-			src = kmap_local_page(old->rq_pages[j]) + offset;
-
-			memcpy(dst, src, len);
-			kunmap(new->rq_pages[j]);
-			kunmap(old->rq_pages[j]);
+			memcpy_page(new->rq_pages[j], offset,
+				    old->rq_pages[j], offset, len);
 		}
 	}
 

fs/cifs/smb2pdu.c

@@ -541,9 +541,10 @@ static void
 assemble_neg_contexts(struct smb2_negotiate_req *req,
 		      struct TCP_Server_Info *server, unsigned int *total_len)
 {
-	char *pneg_ctxt;
-	char *hostname = NULL;
 	unsigned int ctxt_len, neg_context_count;
+	struct TCP_Server_Info *pserver;
+	char *pneg_ctxt;
+	char *hostname;
 
 	if (*total_len > 200) {
 		/* In case length corrupted don't want to overrun smb buffer */
@@ -574,8 +575,9 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 	 * secondary channels don't have the hostname field populated
 	 * use the hostname field in the primary channel instead
 	 */
-	hostname = CIFS_SERVER_IS_CHAN(server) ?
-		server->primary_server->hostname : server->hostname;
+	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
+	cifs_server_lock(pserver);
+	hostname = pserver->hostname;
 	if (hostname && (hostname[0] != 0)) {
 		ctxt_len = build_netname_ctxt((struct smb2_netname_neg_context *)pneg_ctxt,
 					      hostname);
@@ -584,6 +586,7 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 		neg_context_count = 3;
 	} else
 		neg_context_count = 2;
+	cifs_server_unlock(pserver);
 
 	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
 	*total_len += sizeof(struct smb2_posix_neg_context);