Commit 4e456b30 authored by Shyam Prasad N's avatar Shyam Prasad N Committed by Steve French
Browse files

cifs: On cifs_reconnect, resolve the hostname again. 



On cifs_reconnect, make sure that DNS resolution happens again.
It could be the cause of connection to go dead in the first place.

This also contains the fix for a build issue identified by Intel bot.
Reported-by: default avatarkernel test robot <lkp@intel.com>

Signed-off-by: default avatarShyam Prasad N <sprasad@microsoft.com>
Reviewed-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
CC: <stable@vger.kernel.org> # 5.11+
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent e49d033b

fs/cifs/Kconfig

+1 −2
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ config CIFS 
	select CRYPTO_AES

	select CRYPTO_LIB_DES

	select KEYS

	select DNS_RESOLVER

	help

	  This is the client VFS module for the SMB3 family of NAS protocols,

	  (including support for the most recent, most secure dialect SMB3.1.1)
@@ -112,7 +113,6 @@ config CIFS_WEAK_PW_HASH 
config CIFS_UPCALL

	bool "Kerberos/SPNEGO advanced session setup"

	depends on CIFS

	select DNS_RESOLVER

	help

	  Enables an upcall mechanism for CIFS which accesses userspace helper

	  utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets
@@ -179,7 +179,6 @@ config CIFS_DEBUG_DUMP_KEYS 
config CIFS_DFS_UPCALL

	bool "DFS feature support"

	depends on CIFS

	select DNS_RESOLVER

	help

	  Distributed File System (DFS) support is used to access shares

	  transparently in an enterprise name space, even if the share

fs/cifs/Makefile

+3 −2
Original line number Diff line number Diff line
@@ -10,13 +10,14 @@ cifs-y := trace.o cifsfs.o cifssmb.o cifs_debug.o connect.o dir.o file.o \ 
	  cifs_unicode.o nterr.o cifsencrypt.o \

	  readdir.o ioctl.o sess.o export.o smb1ops.o unc.o winucase.o \

	  smb2ops.o smb2maperror.o smb2transport.o \

	  smb2misc.o smb2pdu.o smb2inode.o smb2file.o cifsacl.o fs_context.o

	  smb2misc.o smb2pdu.o smb2inode.o smb2file.o cifsacl.o fs_context.o \

	  dns_resolve.o



cifs-$(CONFIG_CIFS_XATTR) += xattr.o



cifs-$(CONFIG_CIFS_UPCALL) += cifs_spnego.o



cifs-$(CONFIG_CIFS_DFS_UPCALL) += dns_resolve.o cifs_dfs_ref.o dfs_cache.o

cifs-$(CONFIG_CIFS_DFS_UPCALL) += cifs_dfs_ref.o dfs_cache.o



cifs-$(CONFIG_CIFS_SWN_UPCALL) += netlink.o cifs_swn.o

fs/cifs/connect.c

+16 −1
Original line number Diff line number Diff line
@@ -87,7 +87,6 @@ static void cifs_prune_tlinks(struct work_struct *work); 
 *

 * This should be called with server->srv_mutex held.

 */

#ifdef CONFIG_CIFS_DFS_UPCALL

static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)

{

	int rc;
@@ -124,6 +123,7 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server) 
	return !rc ? -1 : 0;

}



#ifdef CONFIG_CIFS_DFS_UPCALL

/* These functions must be called with server->srv_mutex held */

static void reconn_set_next_dfs_target(struct TCP_Server_Info *server,

				       struct cifs_sb_info *cifs_sb,
@@ -321,13 +321,28 @@ cifs_reconnect(struct TCP_Server_Info *server) 
#endif



#ifdef CONFIG_CIFS_DFS_UPCALL

		if (cifs_sb && cifs_sb->origin_fullpath)

			/*

			 * 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_set_next_dfs_target(server, cifs_sb, &tgt_list, &tgt_it);

		else {

#endif

			/*

			 * Resolve the hostname again to make sure that IP address is up-to-date.

			 */

			rc = reconn_set_ipaddr_from_hostname(server);

			if (rc) {

				cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",

						__func__, rc);

			}



#ifdef CONFIG_CIFS_DFS_UPCALL

		}

#endif





#ifdef CONFIG_CIFS_SWN_UPCALL

		}