[STACK] >3k call path in ncpfs

[STACK] >3k call path in ncpfs

[Jörn Engel]

ncpfs has a few stack-hungry functions.  Could you try to put
ncp_ioctl() and/or ncp_conn_logged_in() on a diet?  Example call path
is below.

stackframes for call path too long (3004):
    size  function
     720  ncp_ioctl
     616  ncp_conn_logged_in
      24  ncp_lookup_volume
       0  ncp_request2
     164  sock_sendmsg
       0  wait_on_sync_kiocb
      84  schedule
      16  __put_task_struct
      20  audit_free
      36  audit_log_start
      16  __kmalloc
       0  __get_free_pages
      28  __alloc_pages
     284  try_to_free_pages
       0  out_of_memory
       0  mmput
      16  exit_aio
       0  __put_ioctx
      16  do_munmap
       0  split_vma
      36  vma_adjust
       0  fput
       0  __fput
       0  locks_remove_flock
      12  panic
       0  sys_sync
       0  sync_inodes
     308  sync_inodes_sb
       0  do_writepages
     128  mpage_writepages
       4  write_boundary_block
       0  ll_rw_block
      28  submit_bh
       0  bio_alloc
      88  mempool_alloc
     256  wakeup_bdflush
      20  pdflush_operation
       0  printk
       0  preempt_schedule
      84  schedule

Jörn

-- 
Time? What's that? Time is only worth what you do with it.
-- Theo de Raadt

Re: [STACK] >3k call path in ncpfs

[Byron Stanoszek]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 405 bytes --]

Jörn, do you have any analysis of stack usage for x86-64 or other 64-bit
processors? I assume they would more readily reach the 4K stack boundaries as
all longs and pointers are 8 bytes instead of 4.

Thanks,
  -Byron

--
Byron Stanoszek                         Ph: (330) 644-3059
Systems Programmer                      Fax: (330) 644-8110
Commercial Timesharing Inc.             Email: byron@comtime.com

Re: [STACK] >3k call path in ncpfs

[Jörn Engel]

On Wed, 9 June 2004 14:15:19 -0400, Byron Stanoszek wrote:
> 
> Jörn, do you have any analysis of stack usage for x86-64 or other 64-bit
> processors? I assume they would more readily reach the 4K stack boundaries 
> as all longs and pointers are 8 bytes instead of 4.

No I don't, the tool isn't even tested on anything but i386.  Do any
64bit architectures use 4k stacks?

Jörn

-- 
If you're willing to restrict the flexibility of your approach,
you can almost always do something better.
-- John Carmack

Re: [STACK] >3k call path in ncpfs

[Byron Stanoszek]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 772 bytes --]

On Wed, 9 Jun 2004, Jörn Engel wrote:

> On Wed, 9 June 2004 14:15:19 -0400, Byron Stanoszek wrote:
>>
>> Jörn, do you have any analysis of stack usage for x86-64 or other 64-bit
>> processors? I assume they would more readily reach the 4K stack boundaries
>> as all longs and pointers are 8 bytes instead of 4.
>
> No I don't, the tool isn't even tested on anything but i386.  Do any
> 64bit architectures use 4k stacks?

Guess not :)  I thought I saw it as an option on my x86-64 here but I guess I
was compiling too many different kernels this week.

Sorry for the mixup!

  -Byron

--
Byron Stanoszek                         Ph: (330) 644-3059
Systems Programmer                      Fax: (330) 644-8110
Commercial Timesharing Inc.             Email: byron@comtime.com

[PATCH] Decrease stack usage in ncpfs's ioctl (was Re: [STACK] >3k call path in ncpfs)

[Petr Vandrovec]

On Wed, Jun 09, 2004 at 02:20:02PM +0200, Jörn Engel wrote:
> ncpfs has a few stack-hungry functions.  Could you try to put
> ncp_ioctl() and/or ncp_conn_logged_in() on a diet?  Example call path
> is below.
> 
> stackframes for call path too long (3004):
>     size  function
>      720  ncp_ioctl
>      616  ncp_conn_logged_in

Hi Andrew,
  please apply this. It decreases stack consumption in one of
ncpfs's paths from 3000 to 2200 bytes (and stack portion in ncpfs
ioctl code from 1336 to 452 bytes).
						Thanks,
							Petr Vandrovec

Decrease stack usage in ncpfs's ncp_ioctl: 
* some code used large structure (with embeded 256 bytes for filename) while
  it never passed filename around. Use something smaller in ncp_conn_logged_in.
  Decrease 616 => 300.
* gcc-3.3 is very bad when it comes to parallel blocks in ioctl. Split
  some branches from large switch to separate functions. ncp_ioctl now uses
  152 bytes of stack (instead of 720) and biggest child 64.

Signed-off-by: Petr Vandrovec <vandrove@vc.cvut.cz>

diff -urdN linux/fs/ncpfs/dir.c linux/fs/ncpfs/dir.c
--- linux/fs/ncpfs/dir.c	2004-06-09 19:25:01.000000000 +0000
+++ linux/fs/ncpfs/dir.c	2004-06-09 20:47:09.000000000 +0000
@@ -762,12 +762,12 @@
 int ncp_conn_logged_in(struct super_block *sb)
 {
 	struct ncp_server* server = NCP_SBP(sb);
-	struct nw_info_struct i;
 	int result;
 
 	if (ncp_single_volume(server)) {
 		int len;
 		struct dentry* dent;
+		__u32 volNumber, dirEntNum, DosDirNum;
 		__u8 __name[NCP_MAXPATHLEN + 1];
 
 		len = sizeof(__name);
@@ -776,7 +776,7 @@
 		if (result)
 			goto out;
 		result = -ENOENT;
-		if (ncp_lookup_volume(server, __name, &i)) {
+		if (ncp_get_volume_root(server, __name, &volNumber, &dirEntNum, &DosDirNum)) {
 			PPRINTK("ncp_conn_logged_in: %s not found\n",
 				server->m.mounted_vol);
 			goto out;
@@ -785,9 +785,9 @@
 		if (dent) {
 			struct inode* ino = dent->d_inode;
 			if (ino) {
-				NCP_FINFO(ino)->volNumber = i.volNumber;
-				NCP_FINFO(ino)->dirEntNum = i.dirEntNum;
-				NCP_FINFO(ino)->DosDirNum = i.DosDirNum;
+				NCP_FINFO(ino)->volNumber = volNumber;
+				NCP_FINFO(ino)->dirEntNum = dirEntNum;
+				NCP_FINFO(ino)->DosDirNum = DosDirNum;
 			} else {
 				DPRINTK("ncpfs: sb->s_root->d_inode == NULL!\n");
 			}
diff -urdN linux/fs/ncpfs/ioctl.c linux/fs/ncpfs/ioctl.c
--- linux/fs/ncpfs/ioctl.c	2004-06-09 19:25:01.000000000 +0000
+++ linux/fs/ncpfs/ioctl.c	2004-06-09 21:12:33.000000000 +0000
@@ -29,6 +29,155 @@
 /* maximum negotiable packet size */
 #define NCP_PACKET_SIZE_INTERNAL 65536
 
+static int
+ncp_get_fs_info(struct ncp_server* server, struct inode* inode, struct ncp_fs_info* arg)
+{
+	struct ncp_fs_info info;
+
+	if ((permission(inode, MAY_WRITE, NULL) != 0)
+	    && (current->uid != server->m.mounted_uid)) {
+		return -EACCES;
+	}
+	if (copy_from_user(&info, arg, sizeof(info)))
+		return -EFAULT;
+
+	if (info.version != NCP_GET_FS_INFO_VERSION) {
+		DPRINTK("info.version invalid: %d\n", info.version);
+		return -EINVAL;
+	}
+	/* TODO: info.addr = server->m.serv_addr; */
+	SET_UID(info.mounted_uid, server->m.mounted_uid);
+	info.connection		= server->connection;
+	info.buffer_size	= server->buffer_size;
+	info.volume_number	= NCP_FINFO(inode)->volNumber;
+	info.directory_id	= NCP_FINFO(inode)->DosDirNum;
+
+	if (copy_to_user(arg, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int
+ncp_get_fs_info_v2(struct ncp_server* server, struct inode* inode, struct ncp_fs_info_v2* arg)
+{
+	struct ncp_fs_info_v2 info2;
+
+	if ((permission(inode, MAY_WRITE, NULL) != 0)
+	    && (current->uid != server->m.mounted_uid)) {
+		return -EACCES;
+	}
+	if (copy_from_user(&info2, arg, sizeof(info2)))
+		return -EFAULT;
+
+	if (info2.version != NCP_GET_FS_INFO_VERSION_V2) {
+		DPRINTK("info.version invalid: %d\n", info2.version);
+		return -EINVAL;
+	}
+	info2.mounted_uid   = server->m.mounted_uid;
+	info2.connection    = server->connection;
+	info2.buffer_size   = server->buffer_size;
+	info2.volume_number = NCP_FINFO(inode)->volNumber;
+	info2.directory_id  = NCP_FINFO(inode)->DosDirNum;
+	info2.dummy1 = info2.dummy2 = info2.dummy3 = 0;
+
+	if (copy_to_user(arg, &info2, sizeof(info2)))
+		return -EFAULT;
+	return 0;
+}
+
+#ifdef CONFIG_NCPFS_NLS
+/* Here we are select the iocharset and the codepage for NLS.
+ * Thanks Petr Vandrovec for idea and many hints.
+ */
+static int
+ncp_set_charsets(struct ncp_server* server, struct ncp_nls_ioctl* arg)
+{
+	struct ncp_nls_ioctl user;
+	struct nls_table *codepage;
+	struct nls_table *iocharset;
+	struct nls_table *oldset_io;
+	struct nls_table *oldset_cp;
+			
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+	if (server->root_setuped)
+		return -EBUSY;
+
+	if (copy_from_user(&user, arg, sizeof(user)))
+		return -EFAULT;
+
+	codepage = NULL;
+	user.codepage[NCP_IOCSNAME_LEN] = 0;
+	if (!user.codepage[0] || !strcmp(user.codepage, "default"))
+		codepage = load_nls_default();
+	else {
+		codepage = load_nls(user.codepage);
+		if (!codepage) {
+			return -EBADRQC;
+		}
+	}
+
+	iocharset = NULL;
+	user.iocharset[NCP_IOCSNAME_LEN] = 0;
+	if (!user.iocharset[0] || !strcmp(user.iocharset, "default")) {
+		iocharset = load_nls_default();
+		NCP_CLR_FLAG(server, NCP_FLAG_UTF8);
+	} else if (!strcmp(user.iocharset, "utf8")) {
+		iocharset = load_nls_default();
+		NCP_SET_FLAG(server, NCP_FLAG_UTF8);
+	} else {
+		iocharset = load_nls(user.iocharset);
+		if (!iocharset) {
+			unload_nls(codepage);
+			return -EBADRQC;
+		}
+		NCP_CLR_FLAG(server, NCP_FLAG_UTF8);
+	}
+
+	oldset_cp = server->nls_vol;
+	server->nls_vol = codepage;
+	oldset_io = server->nls_io;
+	server->nls_io = iocharset;
+
+	if (oldset_cp)
+		unload_nls(oldset_cp);
+	if (oldset_io)
+		unload_nls(oldset_io);
+
+	return 0;
+}
+
+static int
+ncp_get_charsets(struct ncp_server* server, struct ncp_nls_ioctl* arg)
+{		
+	struct ncp_nls_ioctl user;
+	int len;
+
+	memset(&user, 0, sizeof(user));
+	if (server->nls_vol && server->nls_vol->charset) {
+		len = strlen(server->nls_vol->charset);
+		if (len > NCP_IOCSNAME_LEN)
+			len = NCP_IOCSNAME_LEN;
+		strncpy(user.codepage, server->nls_vol->charset, len);
+		user.codepage[len] = 0;
+	}
+
+	if (NCP_IS_FLAG(server, NCP_FLAG_UTF8))
+		strcpy(user.iocharset, "utf8");
+	else if (server->nls_io && server->nls_io->charset) {
+		len = strlen(server->nls_io->charset);
+		if (len > NCP_IOCSNAME_LEN)
+			len = NCP_IOCSNAME_LEN;
+		strncpy(user.iocharset,	server->nls_io->charset, len);
+		user.iocharset[len] = 0;
+	}
+
+	if (copy_to_user(arg, &user, sizeof(user)))
+		return -EFAULT;
+	return 0;
+}
+#endif /* CONFIG_NCPFS_NLS */
+
 int ncp_ioctl(struct inode *inode, struct file *filp,
 	      unsigned int cmd, unsigned long arg)
 {
@@ -96,60 +245,10 @@
 		return ncp_conn_logged_in(inode->i_sb);
 
 	case NCP_IOC_GET_FS_INFO:
-		{
-			struct ncp_fs_info info;
-
-			if ((permission(inode, MAY_WRITE, NULL) != 0)
-			    && (current->uid != server->m.mounted_uid)) {
-				return -EACCES;
-			}
-			if (copy_from_user(&info, (struct ncp_fs_info *) arg, 
-				sizeof(info)))
-				return -EFAULT;
-
-			if (info.version != NCP_GET_FS_INFO_VERSION) {
-				DPRINTK("info.version invalid: %d\n", info.version);
-				return -EINVAL;
-			}
-			/* TODO: info.addr = server->m.serv_addr; */
-			SET_UID(info.mounted_uid, server->m.mounted_uid);
-			info.connection		= server->connection;
-			info.buffer_size	= server->buffer_size;
-			info.volume_number	= NCP_FINFO(inode)->volNumber;
-			info.directory_id	= NCP_FINFO(inode)->DosDirNum;
-
-			if (copy_to_user((struct ncp_fs_info *) arg, &info, 
-				sizeof(info))) return -EFAULT;
-			return 0;
-		}
+		return ncp_get_fs_info(server, inode, (struct ncp_fs_info *)arg);
 
 	case NCP_IOC_GET_FS_INFO_V2:
-		{
-			struct ncp_fs_info_v2 info2;
-
-			if ((permission(inode, MAY_WRITE, NULL) != 0)
-			    && (current->uid != server->m.mounted_uid)) {
-				return -EACCES;
-			}
-			if (copy_from_user(&info2, (struct ncp_fs_info_v2 *) arg, 
-				sizeof(info2)))
-				return -EFAULT;
-
-			if (info2.version != NCP_GET_FS_INFO_VERSION_V2) {
-				DPRINTK("info.version invalid: %d\n", info2.version);
-				return -EINVAL;
-			}
-			info2.mounted_uid   = server->m.mounted_uid;
-			info2.connection    = server->connection;
-			info2.buffer_size   = server->buffer_size;
-			info2.volume_number = NCP_FINFO(inode)->volNumber;
-			info2.directory_id  = NCP_FINFO(inode)->DosDirNum;
-			info2.dummy1 = info2.dummy2 = info2.dummy3 = 0;
-
-			if (copy_to_user((struct ncp_fs_info_v2 *) arg, &info2, 
-				sizeof(info2))) return -EFAULT;
-			return 0;
-		}
+		return ncp_get_fs_info_v2(server, inode, (struct ncp_fs_info_v2 *)arg);
 
 	case NCP_IOC_GETMOUNTUID2:
 		{
@@ -201,7 +300,7 @@
 	case NCP_IOC_SETROOT:
 		{
 			struct ncp_setroot_ioctl sr;
-			unsigned int vnum, de, dosde;
+			__u32 vnum, de, dosde;
 			struct dentry* dentry;
 
 			if (!capable(CAP_SYS_ADMIN))
@@ -219,15 +318,10 @@
 				dosde = 0;
 			} else if (sr.volNumber >= NCP_NUMBER_OF_VOLUMES) {
 				return -EINVAL;
-			} else {
-				struct nw_info_struct ni;
-				
-				if (ncp_mount_subdir(server, &ni, sr.volNumber,
-						sr.namespace, sr.dirEntNum))
-					return -ENOENT;
-				vnum = ni.volNumber;
-				de = ni.dirEntNum;
-				dosde = ni.DosDirNum;
+			} else if (ncp_mount_subdir(server, sr.volNumber,
+						sr.namespace, sr.dirEntNum,
+						&vnum, &de, &dosde)) {
+				return -ENOENT;
 			}
 			
 			dentry = inode->i_sb->s_root;
@@ -508,105 +602,14 @@
 		}
 
 #ifdef CONFIG_NCPFS_NLS
-/* Here we are select the iocharset and the codepage for NLS.
- * Thanks Petr Vandrovec for idea and many hints.
- */
 	case NCP_IOC_SETCHARSETS:
-		if (!capable(CAP_SYS_ADMIN))
-			return -EACCES;
-		if (server->root_setuped)
-			return -EBUSY;
-
-		{
-			struct ncp_nls_ioctl user;
-			struct nls_table *codepage;
-			struct nls_table *iocharset;
-			struct nls_table *oldset_io;
-			struct nls_table *oldset_cp;
-			
-			if (copy_from_user(&user, (struct ncp_nls_ioctl*)arg,
-					sizeof(user)))
-				return -EFAULT;
-
-			codepage = NULL;
-			user.codepage[NCP_IOCSNAME_LEN] = 0;
-			if (!user.codepage[0] ||
-					!strcmp(user.codepage, "default"))
-				codepage = load_nls_default();
-			else {
-				codepage = load_nls(user.codepage);
-				if (!codepage) {
-					return -EBADRQC;
-				}
-			}
-
-			iocharset = NULL;
-			user.iocharset[NCP_IOCSNAME_LEN] = 0;
-			if (!user.iocharset[0] ||
-					!strcmp(user.iocharset, "default")) {
-				iocharset = load_nls_default();
-				NCP_CLR_FLAG(server, NCP_FLAG_UTF8);
-			} else {
-				if (!strcmp(user.iocharset, "utf8")) {
-					iocharset = load_nls_default();
-					NCP_SET_FLAG(server, NCP_FLAG_UTF8);
-				} else {
-					iocharset = load_nls(user.iocharset);
-					if (!iocharset) {
-						unload_nls(codepage);
-						return -EBADRQC;
-					}
-					NCP_CLR_FLAG(server, NCP_FLAG_UTF8);
-				}
-			}
-
-			oldset_cp = server->nls_vol;
-			server->nls_vol = codepage;
-			oldset_io = server->nls_io;
-			server->nls_io = iocharset;
-
-			if (oldset_cp)
-				unload_nls(oldset_cp);
-			if (oldset_io)
-				unload_nls(oldset_io);
-
-			return 0;
-		}
+		return ncp_set_charsets(server, (struct ncp_nls_ioctl *)arg);
 		
-	case NCP_IOC_GETCHARSETS: /* not tested */
-		{
-			struct ncp_nls_ioctl user;
-			int len;
-
-			memset(&user, 0, sizeof(user));
-			if (server->nls_vol && server->nls_vol->charset) {
-				len = strlen(server->nls_vol->charset);
-				if (len > NCP_IOCSNAME_LEN)
-					len = NCP_IOCSNAME_LEN;
-				strncpy(user.codepage,
-						server->nls_vol->charset, len);
-				user.codepage[len] = 0;
-			}
-
-			if (NCP_IS_FLAG(server, NCP_FLAG_UTF8))
-				strcpy(user.iocharset, "utf8");
-			else
-				if (server->nls_io && server->nls_io->charset) {
-					len = strlen(server->nls_io->charset);
-					if (len > NCP_IOCSNAME_LEN)
-						len = NCP_IOCSNAME_LEN;
-					strncpy(user.iocharset,
-						server->nls_io->charset, len);
-					user.iocharset[len] = 0;
-				}
-
-			if (copy_to_user((struct ncp_nls_ioctl*)arg, &user,
-					sizeof(user)))
-				return -EFAULT;
+	case NCP_IOC_GETCHARSETS:
+		return ncp_get_charsets(server, (struct ncp_nls_ioctl *)arg);
 
-			return 0;
-		}
 #endif /* CONFIG_NCPFS_NLS */
+
 	case NCP_IOC_SETDENTRYTTL:
 		if ((permission(inode, MAY_WRITE, NULL) != 0) &&
 				 (current->uid != server->m.mounted_uid))
diff -urdN linux/fs/ncpfs/ncplib_kernel.c linux/fs/ncpfs/ncplib_kernel.c
--- linux/fs/ncpfs/ncplib_kernel.c	2004-06-09 19:24:45.000000000 +0000
+++ linux/fs/ncpfs/ncplib_kernel.c	2004-06-09 21:10:25.000000000 +0000
@@ -536,37 +536,34 @@
 }
 
 int
-ncp_mount_subdir(struct ncp_server *server, struct nw_info_struct *i,
-			__u8 volNumber, __u8 srcNS, __u32 dirEntNum)
+ncp_mount_subdir(struct ncp_server *server,
+		 __u8 volNumber, __u8 srcNS, __u32 dirEntNum,
+		 __u32* volume, __u32* newDirEnt, __u32* newDosEnt)
 {
 	int dstNS;
 	int result;
-	__u32 newDirEnt;
-	__u32 newDosEnt;
 	
 	dstNS = ncp_get_known_namespace(server, volNumber);
 	if ((result = ncp_ObtainSpecificDirBase(server, srcNS, dstNS, volNumber, 
-				      dirEntNum, NULL, &newDirEnt, &newDosEnt)) != 0)
+				      dirEntNum, NULL, newDirEnt, newDosEnt)) != 0)
 	{
 		return result;
 	}
 	server->name_space[volNumber] = dstNS;
-	i->volNumber = volNumber;
-	i->dirEntNum = newDirEnt;
-	i->DosDirNum = newDosEnt;
+	*volume = volNumber;
 	server->m.mounted_vol[1] = 0;
 	server->m.mounted_vol[0] = 'X';
 	return 0;
 }
 
 int 
-ncp_lookup_volume(struct ncp_server *server, char *volname,
-		      struct nw_info_struct *target)
+ncp_get_volume_root(struct ncp_server *server, const char *volname,
+		    __u32* volume, __u32* dirent, __u32* dosdirent)
 {
 	int result;
-	int volnum;
+	__u8 volnum;
 
-	DPRINTK("ncp_lookup_volume: looking up vol %s\n", volname);
+	DPRINTK("ncp_get_volume_root: looking up vol %s\n", volname);
 
 	ncp_init_request(server);
 	ncp_add_byte(server, 22);	/* Subfunction: Generate dir handle */
@@ -585,16 +582,31 @@
 		ncp_unlock_server(server);
 		return result;
 	}
-	memset(target, 0, sizeof(*target));
-	target->DosDirNum = target->dirEntNum = ncp_reply_dword(server, 4);
-	target->volNumber = volnum = ncp_reply_byte(server, 8);
+	*dirent = *dosdirent = ncp_reply_dword(server, 4);
+	volnum = ncp_reply_byte(server, 8);
 	ncp_unlock_server(server);
-
+	*volume = volnum;
+	
 	server->name_space[volnum] = ncp_get_known_namespace(server, volnum);
-
+	
 	DPRINTK("lookup_vol: namespace[%d] = %d\n",
 		volnum, server->name_space[volnum]);
 
+	return 0;
+}
+
+int 
+ncp_lookup_volume(struct ncp_server *server, const char *volname,
+		  struct nw_info_struct *target)
+{
+	int result;
+
+	memset(target, 0, sizeof(*target));
+	result = ncp_get_volume_root(server, volname,
+			&target->volNumber, &target->dirEntNum, &target->DosDirNum);
+	if (result) {
+		return result;
+	}
 	target->nameLen = strlen(volname);
 	memcpy(target->entryName, volname, target->nameLen+1);
 	target->attributes = aDIR;
diff -urdN linux/fs/ncpfs/ncplib_kernel.h linux/fs/ncpfs/ncplib_kernel.h
--- linux/fs/ncpfs/ncplib_kernel.h	2004-06-09 19:24:13.000000000 +0000
+++ linux/fs/ncpfs/ncplib_kernel.h	2004-06-09 21:11:11.000000000 +0000
@@ -70,7 +70,9 @@
 int ncp_obtain_info(struct ncp_server *server, struct inode *, char *,
 		struct nw_info_struct *target);
 int ncp_obtain_nfs_info(struct ncp_server *server, struct nw_info_struct *target);
-int ncp_lookup_volume(struct ncp_server *, char *, struct nw_info_struct *);
+int ncp_get_volume_root(struct ncp_server *server, const char *volname, 
+			__u32 *volume, __u32 *dirent, __u32 *dosdirent);
+int ncp_lookup_volume(struct ncp_server *, const char *, struct nw_info_struct *);
 int ncp_modify_file_or_subdir_dos_info(struct ncp_server *, struct inode *,
 	 __u32, const struct nw_modify_dos_info *info);
 int ncp_modify_file_or_subdir_dos_info_path(struct ncp_server *, struct inode *,
@@ -111,8 +113,8 @@
 #endif	/* CONFIG_NCPFS_IOCTL_LOCKING */
 
 int
-ncp_mount_subdir(struct ncp_server *, struct nw_info_struct *,
-			__u8, __u8, __u32);
+ncp_mount_subdir(struct ncp_server *, __u8, __u8, __u32,
+		 __u32* volume, __u32* dirent, __u32* dosdirent);
 int ncp_dirhandle_alloc(struct ncp_server *, __u8 vol, __u32 dirent, __u8 *dirhandle);
 int ncp_dirhandle_free(struct ncp_server *, __u8 dirhandle);